Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 7538 insertions, 0 deletions

diff --git a/gfx/angle/checkout/src/compiler/translator/ParseContext.cpp b/gfx/angle/checkout/src/compiler/translator/ParseContext.cpp
new file mode 100644
index 0000000000..4312c2c966
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/ParseContext.cpp
@@ -0,0 +1,7538 @@
+//
+// Copyright 2002 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#include "compiler/translator/ParseContext.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "common/mathutil.h"
+#include "common/utilities.h"
+#include "compiler/preprocessor/SourceLocation.h"
+#include "compiler/translator/Declarator.h"
+#include "compiler/translator/StaticType.h"
+#include "compiler/translator/ValidateGlobalInitializer.h"
+#include "compiler/translator/ValidateSwitch.h"
+#include "compiler/translator/glslang.h"
+#include "compiler/translator/tree_util/IntermNode_util.h"
+#include "compiler/translator/util.h"
+
+namespace sh
+{
+
+///////////////////////////////////////////////////////////////////////
+//
+// Sub- vector and matrix fields
+//
+////////////////////////////////////////////////////////////////////////
+
+namespace
+{
+
+const int kWebGLMaxStructNesting = 4;
+
+bool ContainsSampler(const TStructure *structType);
+
+bool ContainsSampler(const TType &type)
+{
+    if (IsSampler(type.getBasicType()))
+    {
+        return true;
+    }
+    if (type.getBasicType() == EbtStruct)
+    {
+        return ContainsSampler(type.getStruct());
+    }
+
+    return false;
+}
+
+bool ContainsSampler(const TStructure *structType)
+{
+    for (const auto &field : structType->fields())
+    {
+        if (ContainsSampler(*field->type()))
+            return true;
+    }
+    return false;
+}
+
+// Get a token from an image argument to use as an error message token.
+const char *GetImageArgumentToken(TIntermTyped *imageNode)
+{
+    ASSERT(IsImage(imageNode->getBasicType()));
+    while (imageNode->getAsBinaryNode() &&
+           (imageNode->getAsBinaryNode()->getOp() == EOpIndexIndirect ||
+            imageNode->getAsBinaryNode()->getOp() == EOpIndexDirect))
+    {
+        imageNode = imageNode->getAsBinaryNode()->getLeft();
+    }
+    TIntermSymbol *imageSymbol = imageNode->getAsSymbolNode();
+    if (imageSymbol)
+    {
+        return imageSymbol->getName().data();
+    }
+    return "image";
+}
+
+bool CanSetDefaultPrecisionOnType(const TPublicType &type)
+{
+    if (!SupportsPrecision(type.getBasicType()))
+    {
+        return false;
+    }
+    if (type.getBasicType() == EbtUInt)
+    {
+        // ESSL 3.00.4 section 4.5.4
+        return false;
+    }
+    if (type.isAggregate())
+    {
+        // Not allowed to set for aggregate types
+        return false;
+    }
+    return true;
+}
+
+// Map input primitive types to input array sizes in a geometry shader.
+GLuint GetGeometryShaderInputArraySize(TLayoutPrimitiveType primitiveType)
+{
+    switch (primitiveType)
+    {
+        case EptPoints:
+            return 1u;
+        case EptLines:
+            return 2u;
+        case EptTriangles:
+            return 3u;
+        case EptLinesAdjacency:
+            return 4u;
+        case EptTrianglesAdjacency:
+            return 6u;
+        default:
+            UNREACHABLE();
+            return 0u;
+    }
+}
+
+bool IsBufferOrSharedVariable(TIntermTyped *var)
+{
+    if (var->isInterfaceBlock() || var->getQualifier() == EvqBuffer ||
+        var->getQualifier() == EvqShared)
+    {
+        return true;
+    }
+    return false;
+}
+
+TIntermTyped *FindLValueBase(TIntermTyped *node)
+{
+    do
+    {
+        const TIntermBinary *binary = node->getAsBinaryNode();
+        if (binary == nullptr)
+        {
+            return node;
+        }
+
+        TOperator op = binary->getOp();
+        if (op != EOpIndexDirect && op != EOpIndexIndirect)
+        {
+            return static_cast<TIntermTyped *>(nullptr);
+        }
+
+        node = binary->getLeft();
+    } while (true);
+}
+
+void AddAdvancedBlendEquation(gl::BlendEquationType eq, TLayoutQualifier *qualifier)
+{
+    qualifier->advancedBlendEquations.set(static_cast<uint32_t>(eq));
+}
+
+constexpr bool IsValidWithPixelLocalStorage(TLayoutImageInternalFormat internalFormat)
+{
+    switch (internalFormat)
+    {
+        case EiifRGBA8:
+        case EiifRGBA8I:
+        case EiifRGBA8UI:
+        case EiifR32F:
+        case EiifR32UI:
+            return true;
+        default:
+            return false;
+    }
+}
+}  // namespace
+
+// This tracks each binding point's current default offset for inheritance of subsequent
+// variables using the same binding, and keeps offsets unique and non overlapping.
+// See GLSL ES 3.1, section 4.4.6.
+class TParseContext::AtomicCounterBindingState
+{
+  public:
+    AtomicCounterBindingState() : mDefaultOffset(0) {}
+    // Inserts a new span and returns -1 if overlapping, else returns the starting offset of
+    // newly inserted span.
+    int insertSpan(int start, size_t length)
+    {
+        gl::RangeI newSpan(start, start + static_cast<int>(length));
+        for (const auto &span : mSpans)
+        {
+            if (newSpan.intersects(span))
+            {
+                return -1;
+            }
+        }
+        mSpans.push_back(newSpan);
+        mDefaultOffset = newSpan.high();
+        return start;
+    }
+    // Inserts a new span starting from the default offset.
+    int appendSpan(size_t length) { return insertSpan(mDefaultOffset, length); }
+    void setDefaultOffset(int offset) { mDefaultOffset = offset; }
+
+  private:
+    int mDefaultOffset;
+    std::vector<gl::RangeI> mSpans;
+};
+
+TParseContext::TParseContext(TSymbolTable &symt,
+                             TExtensionBehavior &ext,
+                             sh::GLenum type,
+                             ShShaderSpec spec,
+                             const ShCompileOptions &options,
+                             bool checksPrecErrors,
+                             TDiagnostics *diagnostics,
+                             const ShBuiltInResources &resources,
+                             ShShaderOutput outputType)
+    : symbolTable(symt),
+      mDeferredNonEmptyDeclarationErrorCheck(false),
+      mShaderType(type),
+      mShaderSpec(spec),
+      mCompileOptions(options),
+      mShaderVersion(100),
+      mTreeRoot(nullptr),
+      mLoopNestingLevel(0),
+      mStructNestingLevel(0),
+      mSwitchNestingLevel(0),
+      mCurrentFunctionType(nullptr),
+      mFunctionReturnsValue(false),
+      mChecksPrecisionErrors(checksPrecErrors),
+      mFragmentPrecisionHighOnESSL1(false),
+      mEarlyFragmentTestsSpecified(false),
+      mHasDiscard(false),
+      mSampleQualifierSpecified(false),
+      mDefaultUniformMatrixPacking(EmpColumnMajor),
+      mDefaultUniformBlockStorage(sh::IsWebGLBasedSpec(spec) ? EbsStd140 : EbsShared),
+      mDefaultBufferMatrixPacking(EmpColumnMajor),
+      mDefaultBufferBlockStorage(sh::IsWebGLBasedSpec(spec) ? EbsStd140 : EbsShared),
+      mDiagnostics(diagnostics),
+      mDirectiveHandler(ext, *mDiagnostics, mShaderVersion, mShaderType),
+      mPreprocessor(mDiagnostics, &mDirectiveHandler, angle::pp::PreprocessorSettings(spec)),
+      mScanner(nullptr),
+      mMinProgramTexelOffset(resources.MinProgramTexelOffset),
+      mMaxProgramTexelOffset(resources.MaxProgramTexelOffset),
+      mMinProgramTextureGatherOffset(resources.MinProgramTextureGatherOffset),
+      mMaxProgramTextureGatherOffset(resources.MaxProgramTextureGatherOffset),
+      mComputeShaderLocalSizeDeclared(false),
+      mComputeShaderLocalSize(-1),
+      mNumViews(-1),
+      mMaxNumViews(resources.MaxViewsOVR),
+      mMaxImageUnits(resources.MaxImageUnits),
+      mMaxCombinedTextureImageUnits(resources.MaxCombinedTextureImageUnits),
+      mMaxUniformLocations(resources.MaxUniformLocations),
+      mMaxUniformBufferBindings(resources.MaxUniformBufferBindings),
+      mMaxVertexAttribs(resources.MaxVertexAttribs),
+      mMaxAtomicCounterBindings(resources.MaxAtomicCounterBindings),
+      mMaxShaderStorageBufferBindings(resources.MaxShaderStorageBufferBindings),
+      mDeclaringFunction(false),
+      mGeometryShaderInputPrimitiveType(EptUndefined),
+      mGeometryShaderOutputPrimitiveType(EptUndefined),
+      mGeometryShaderInvocations(0),
+      mGeometryShaderMaxVertices(-1),
+      mMaxGeometryShaderInvocations(resources.MaxGeometryShaderInvocations),
+      mMaxGeometryShaderMaxVertices(resources.MaxGeometryOutputVertices),
+      mGeometryInputArraySize(0),
+      mMaxPatchVertices(resources.MaxPatchVertices),
+      mTessControlShaderOutputVertices(0),
+      mTessEvaluationShaderInputPrimitiveType(EtetUndefined),
+      mTessEvaluationShaderInputVertexSpacingType(EtetUndefined),
+      mTessEvaluationShaderInputOrderingType(EtetUndefined),
+      mTessEvaluationShaderInputPointType(EtetUndefined),
+      mHasAnyPreciseType(false),
+      mAdvancedBlendEquations(0),
+      mFunctionBodyNewScope(false),
+      mOutputType(outputType)
+{}
+
+TParseContext::~TParseContext() {}
+
+bool TParseContext::anyMultiviewExtensionAvailable()
+{
+    return isExtensionEnabled(TExtension::OVR_multiview) ||
+           isExtensionEnabled(TExtension::OVR_multiview2);
+}
+
+bool TParseContext::parseVectorFields(const TSourceLoc &line,
+                                      const ImmutableString &compString,
+                                      int vecSize,
+                                      TVector<int> *fieldOffsets)
+{
+    ASSERT(fieldOffsets);
+    size_t fieldCount = compString.length();
+    if (fieldCount > 4u)
+    {
+        error(line, "illegal vector field selection", compString);
+        return false;
+    }
+    fieldOffsets->resize(fieldCount);
+
+    enum
+    {
+        exyzw,
+        ergba,
+        estpq
+    } fieldSet[4];
+
+    for (unsigned int i = 0u; i < fieldOffsets->size(); ++i)
+    {
+        switch (compString[i])
+        {
+            case 'x':
+                (*fieldOffsets)[i] = 0;
+                fieldSet[i]        = exyzw;
+                break;
+            case 'r':
+                (*fieldOffsets)[i] = 0;
+                fieldSet[i]        = ergba;
+                break;
+            case 's':
+                (*fieldOffsets)[i] = 0;
+                fieldSet[i]        = estpq;
+                break;
+            case 'y':
+                (*fieldOffsets)[i] = 1;
+                fieldSet[i]        = exyzw;
+                break;
+            case 'g':
+                (*fieldOffsets)[i] = 1;
+                fieldSet[i]        = ergba;
+                break;
+            case 't':
+                (*fieldOffsets)[i] = 1;
+                fieldSet[i]        = estpq;
+                break;
+            case 'z':
+                (*fieldOffsets)[i] = 2;
+                fieldSet[i]        = exyzw;
+                break;
+            case 'b':
+                (*fieldOffsets)[i] = 2;
+                fieldSet[i]        = ergba;
+                break;
+            case 'p':
+                (*fieldOffsets)[i] = 2;
+                fieldSet[i]        = estpq;
+                break;
+
+            case 'w':
+                (*fieldOffsets)[i] = 3;
+                fieldSet[i]        = exyzw;
+                break;
+            case 'a':
+                (*fieldOffsets)[i] = 3;
+                fieldSet[i]        = ergba;
+                break;
+            case 'q':
+                (*fieldOffsets)[i] = 3;
+                fieldSet[i]        = estpq;
+                break;
+            default:
+                error(line, "illegal vector field selection", compString);
+                return false;
+        }
+    }
+
+    for (unsigned int i = 0u; i < fieldOffsets->size(); ++i)
+    {
+        if ((*fieldOffsets)[i] >= vecSize)
+        {
+            error(line, "vector field selection out of range", compString);
+            return false;
+        }
+
+        if (i > 0)
+        {
+            if (fieldSet[i] != fieldSet[i - 1])
+            {
+                error(line, "illegal - vector component fields not from the same set", compString);
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////
+//
+// Errors
+//
+////////////////////////////////////////////////////////////////////////
+
+//
+// Used by flex/bison to output all syntax and parsing errors.
+//
+void TParseContext::error(const TSourceLoc &loc, const char *reason, const char *token)
+{
+    mDiagnostics->error(loc, reason, token);
+}
+
+void TParseContext::error(const TSourceLoc &loc, const char *reason, const ImmutableString &token)
+{
+    mDiagnostics->error(loc, reason, token.data());
+}
+
+void TParseContext::warning(const TSourceLoc &loc, const char *reason, const char *token)
+{
+    mDiagnostics->warning(loc, reason, token);
+}
+
+void TParseContext::errorIfPLSDeclared(const TSourceLoc &loc, PLSIllegalOperations op)
+{
+    if (!isExtensionEnabled(TExtension::ANGLE_shader_pixel_local_storage))
+    {
+        return;
+    }
+    if (mPLSBindings.empty())
+    {
+        // No pixel local storage uniforms have been declared yet. Remember this potential error in
+        // case PLS gets declared later.
+        mPLSPotentialErrors.emplace_back(loc, op);
+        return;
+    }
+    switch (op)
+    {
+        case PLSIllegalOperations::Discard:
+            error(loc, "illegal discard when pixel local storage is declared", "discard");
+            break;
+        case PLSIllegalOperations::ReturnFromMain:
+            error(loc, "illegal return from main when pixel local storage is declared", "return");
+            break;
+        case PLSIllegalOperations::AssignFragDepth:
+            error(loc, "value not assignable when pixel local storage is declared", "gl_FragDepth");
+            break;
+        case PLSIllegalOperations::AssignSampleMask:
+            error(loc, "value not assignable when pixel local storage is declared",
+                  "gl_SampleMask");
+            break;
+    }
+}
+
+void TParseContext::outOfRangeError(bool isError,
+                                    const TSourceLoc &loc,
+                                    const char *reason,
+                                    const char *token)
+{
+    if (isError)
+    {
+        error(loc, reason, token);
+    }
+    else
+    {
+        warning(loc, reason, token);
+    }
+}
+
+void TParseContext::setTreeRoot(TIntermBlock *treeRoot)
+{
+    mTreeRoot = treeRoot;
+    mTreeRoot->setIsTreeRoot();
+}
+
+//
+// Same error message for all places assignments don't work.
+//
+void TParseContext::assignError(const TSourceLoc &line,
+                                const char *op,
+                                const TType &left,
+                                const TType &right)
+{
+    TInfoSinkBase reasonStream;
+    reasonStream << "cannot convert from '" << right << "' to '" << left << "'";
+    error(line, reasonStream.c_str(), op);
+}
+
+//
+// Same error message for all places unary operations don't work.
+//
+void TParseContext::unaryOpError(const TSourceLoc &line, const char *op, const TType &operand)
+{
+    TInfoSinkBase reasonStream;
+    reasonStream << "wrong operand type - no operation '" << op
+                 << "' exists that takes an operand of type " << operand
+                 << " (or there is no acceptable conversion)";
+    error(line, reasonStream.c_str(), op);
+}
+
+//
+// Same error message for all binary operations don't work.
+//
+void TParseContext::binaryOpError(const TSourceLoc &line,
+                                  const char *op,
+                                  const TType &left,
+                                  const TType &right)
+{
+    TInfoSinkBase reasonStream;
+    reasonStream << "wrong operand types - no operation '" << op
+                 << "' exists that takes a left-hand operand of type '" << left
+                 << "' and a right operand of type '" << right
+                 << "' (or there is no acceptable conversion)";
+    error(line, reasonStream.c_str(), op);
+}
+
+void TParseContext::checkPrecisionSpecified(const TSourceLoc &line,
+                                            TPrecision precision,
+                                            TBasicType type)
+{
+    if (!mChecksPrecisionErrors)
+        return;
+
+    if (precision != EbpUndefined && !SupportsPrecision(type))
+    {
+        error(line, "illegal type for precision qualifier", getBasicString(type));
+    }
+
+    if (precision == EbpUndefined)
+    {
+        switch (type)
+        {
+            case EbtFloat:
+                error(line, "No precision specified for (float)", "");
+                return;
+            case EbtInt:
+            case EbtUInt:
+                UNREACHABLE();  // there's always a predeclared qualifier
+                error(line, "No precision specified (int)", "");
+                return;
+            default:
+                if (IsOpaqueType(type))
+                {
+                    error(line, "No precision specified", getBasicString(type));
+                    return;
+                }
+        }
+    }
+}
+
+void TParseContext::markStaticReadIfSymbol(TIntermNode *node)
+{
+    TIntermSwizzle *swizzleNode = node->getAsSwizzleNode();
+    if (swizzleNode)
+    {
+        markStaticReadIfSymbol(swizzleNode->getOperand());
+        return;
+    }
+    TIntermBinary *binaryNode = node->getAsBinaryNode();
+    if (binaryNode)
+    {
+        switch (binaryNode->getOp())
+        {
+            case EOpIndexDirect:
+            case EOpIndexIndirect:
+            case EOpIndexDirectStruct:
+            case EOpIndexDirectInterfaceBlock:
+                markStaticReadIfSymbol(binaryNode->getLeft());
+                return;
+            default:
+                return;
+        }
+    }
+    TIntermSymbol *symbolNode = node->getAsSymbolNode();
+    if (symbolNode)
+    {
+        symbolTable.markStaticRead(symbolNode->variable());
+    }
+}
+
+// Both test and if necessary, spit out an error, to see if the node is really
+// an l-value that can be operated on this way.
+bool TParseContext::checkCanBeLValue(const TSourceLoc &line, const char *op, TIntermTyped *node)
+{
+    TIntermSwizzle *swizzleNode = node->getAsSwizzleNode();
+    if (swizzleNode)
+    {
+        bool ok = checkCanBeLValue(line, op, swizzleNode->getOperand());
+        if (ok && swizzleNode->hasDuplicateOffsets())
+        {
+            error(line, " l-value of swizzle cannot have duplicate components", op);
+            return false;
+        }
+        return ok;
+    }
+
+    TIntermBinary *binaryNode = node->getAsBinaryNode();
+    if (binaryNode)
+    {
+        switch (binaryNode->getOp())
+        {
+            case EOpIndexDirect:
+            case EOpIndexIndirect:
+            case EOpIndexDirectStruct:
+            case EOpIndexDirectInterfaceBlock:
+                if (node->getMemoryQualifier().readonly)
+                {
+                    error(line, "can't modify a readonly variable", op);
+                    return false;
+                }
+                return checkCanBeLValue(line, op, binaryNode->getLeft());
+            default:
+                break;
+        }
+        error(line, " l-value required", op);
+        return false;
+    }
+
+    std::string message;
+    switch (node->getQualifier())
+    {
+        case EvqConst:
+            message = "can't modify a const";
+            break;
+        case EvqParamConst:
+            message = "can't modify a const";
+            break;
+        case EvqAttribute:
+            message = "can't modify an attribute";
+            break;
+        case EvqFragmentIn:
+        case EvqVertexIn:
+        case EvqGeometryIn:
+        case EvqTessControlIn:
+        case EvqTessEvaluationIn:
+        case EvqFlatIn:
+        case EvqNoPerspectiveIn:
+        case EvqSmoothIn:
+        case EvqCentroidIn:
+        case EvqSampleIn:
+            message = "can't modify an input";
+            break;
+        case EvqUniform:
+            message = "can't modify a uniform";
+            break;
+        case EvqVaryingIn:
+            message = "can't modify a varying";
+            break;
+        case EvqFragCoord:
+            message = "can't modify gl_FragCoord";
+            break;
+        case EvqFrontFacing:
+            message = "can't modify gl_FrontFacing";
+            break;
+        case EvqHelperInvocation:
+            message = "can't modify gl_HelperInvocation";
+            break;
+        case EvqPointCoord:
+            message = "can't modify gl_PointCoord";
+            break;
+        case EvqNumWorkGroups:
+            message = "can't modify gl_NumWorkGroups";
+            break;
+        case EvqWorkGroupSize:
+            message = "can't modify gl_WorkGroupSize";
+            break;
+        case EvqWorkGroupID:
+            message = "can't modify gl_WorkGroupID";
+            break;
+        case EvqLocalInvocationID:
+            message = "can't modify gl_LocalInvocationID";
+            break;
+        case EvqGlobalInvocationID:
+            message = "can't modify gl_GlobalInvocationID";
+            break;
+        case EvqLocalInvocationIndex:
+            message = "can't modify gl_LocalInvocationIndex";
+            break;
+        case EvqViewIDOVR:
+            message = "can't modify gl_ViewID_OVR";
+            break;
+        case EvqComputeIn:
+            message = "can't modify work group size variable";
+            break;
+        case EvqPerVertexIn:
+            message = "can't modify any member in gl_in";
+            break;
+        case EvqPrimitiveIDIn:
+            message = "can't modify gl_PrimitiveIDIn";
+            break;
+        case EvqInvocationID:
+            message = "can't modify gl_InvocationID";
+            break;
+        case EvqPrimitiveID:
+            if (mShaderType == GL_FRAGMENT_SHADER)
+            {
+                message = "can't modify gl_PrimitiveID in a fragment shader";
+            }
+            break;
+        case EvqLayerIn:
+            message = "can't modify gl_Layer in a fragment shader";
+            break;
+        case EvqSampleID:
+            message = "can't modify gl_SampleID";
+            break;
+        case EvqSampleMaskIn:
+            message = "can't modify gl_SampleMaskIn";
+            break;
+        case EvqSamplePosition:
+            message = "can't modify gl_SamplePosition";
+            break;
+        case EvqClipDistance:
+            if (mShaderType == GL_FRAGMENT_SHADER)
+            {
+                message = "can't modify gl_ClipDistance in a fragment shader";
+            }
+            break;
+        case EvqCullDistance:
+            if (mShaderType == GL_FRAGMENT_SHADER)
+            {
+                message = "can't modify gl_CullDistance in a fragment shader";
+            }
+            break;
+        case EvqFragDepth:
+            errorIfPLSDeclared(line, PLSIllegalOperations::AssignFragDepth);
+            break;
+        case EvqSampleMask:
+            errorIfPLSDeclared(line, PLSIllegalOperations::AssignSampleMask);
+            break;
+        default:
+            //
+            // Type that can't be written to?
+            //
+            if (node->getBasicType() == EbtVoid)
+            {
+                message = "can't modify void";
+            }
+            if (IsOpaqueType(node->getBasicType()))
+            {
+                message = "can't modify a variable with type ";
+                message += getBasicString(node->getBasicType());
+            }
+            else if (node->getMemoryQualifier().readonly)
+            {
+                message = "can't modify a readonly variable";
+            }
+    }
+
+    ASSERT(binaryNode == nullptr && swizzleNode == nullptr);
+    TIntermSymbol *symNode = node->getAsSymbolNode();
+    if (message.empty() && symNode != nullptr)
+    {
+        symbolTable.markStaticWrite(symNode->variable());
+        return true;
+    }
+
+    std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
+    reasonStream << "l-value required";
+    if (!message.empty())
+    {
+        if (symNode)
+        {
+            // Symbol inside an expression can't be nameless.
+            ASSERT(symNode->variable().symbolType() != SymbolType::Empty);
+            const ImmutableString &symbol = symNode->getName();
+            reasonStream << " (" << message << " \"" << symbol << "\")";
+        }
+        else
+        {
+            reasonStream << " (" << message << ")";
+        }
+    }
+    std::string reason = reasonStream.str();
+    error(line, reason.c_str(), op);
+
+    return false;
+}
+
+// Both test, and if necessary spit out an error, to see if the node is really
+// a constant.
+void TParseContext::checkIsConst(TIntermTyped *node)
+{
+    if (node->getQualifier() != EvqConst)
+    {
+        error(node->getLine(), "constant expression required", "");
+    }
+}
+
+// Both test, and if necessary spit out an error, to see if the node is really
+// an integer.
+void TParseContext::checkIsScalarInteger(TIntermTyped *node, const char *token)
+{
+    if (!node->isScalarInt())
+    {
+        error(node->getLine(), "integer expression required", token);
+    }
+}
+
+// Both test, and if necessary spit out an error, to see if we are currently
+// globally scoped.
+bool TParseContext::checkIsAtGlobalLevel(const TSourceLoc &line, const char *token)
+{
+    if (!symbolTable.atGlobalLevel())
+    {
+        error(line, "only allowed at global scope", token);
+        return false;
+    }
+    return true;
+}
+
+// ESSL 3.00.5 sections 3.8 and 3.9.
+// If it starts "gl_" or contains two consecutive underscores, it's reserved.
+// Also checks for "webgl_" and "_webgl_" reserved identifiers if parsing a webgl shader.
+bool TParseContext::checkIsNotReserved(const TSourceLoc &line, const ImmutableString &identifier)
+{
+    static const char *reservedErrMsg = "reserved built-in name";
+    if (gl::IsBuiltInName(identifier.data()))
+    {
+        error(line, reservedErrMsg, "gl_");
+        return false;
+    }
+    if (sh::IsWebGLBasedSpec(mShaderSpec))
+    {
+        if (identifier.beginsWith("webgl_"))
+        {
+            error(line, reservedErrMsg, "webgl_");
+            return false;
+        }
+        if (identifier.beginsWith("_webgl_"))
+        {
+            error(line, reservedErrMsg, "_webgl_");
+            return false;
+        }
+    }
+    if (identifier.contains("__"))
+    {
+        if (sh::IsWebGLBasedSpec(mShaderSpec))
+        {
+            error(line,
+                  "identifiers containing two consecutive underscores (__) are reserved as "
+                  "possible future keywords",
+                  identifier);
+            return false;
+        }
+        else
+        {
+            // Using double underscores is allowed, but may result in unintended behaviors, so a
+            // warning is issued.
+            // OpenGL ES Shader Language 3.2 specification:
+            // > 3.7. Keywords
+            // > ...
+            // > In addition, all identifiers containing two consecutive underscores (__) are
+            // > reserved for use by underlying software layers. Defining such a name in a shader
+            // > does not itself result in an error, but may result in unintended behaviors that
+            // > stem from having multiple definitions of the same name.
+            warning(line,
+                    "all identifiers containing two consecutive underscores (__) are reserved - "
+                    "unintented behaviors are possible",
+                    identifier.data());
+        }
+    }
+    return true;
+}
+
+// Make sure the argument types are correct for constructing a specific type.
+bool TParseContext::checkConstructorArguments(const TSourceLoc &line,
+                                              const TIntermSequence &arguments,
+                                              const TType &type)
+{
+    if (arguments.empty())
+    {
+        error(line, "constructor does not have any arguments", "constructor");
+        return false;
+    }
+
+    for (TIntermNode *arg : arguments)
+    {
+        markStaticReadIfSymbol(arg);
+        const TIntermTyped *argTyped = arg->getAsTyped();
+        ASSERT(argTyped != nullptr);
+        if (type.getBasicType() != EbtStruct && IsOpaqueType(argTyped->getBasicType()))
+        {
+            std::string reason("cannot convert a variable with type ");
+            reason += getBasicString(argTyped->getBasicType());
+            error(line, reason.c_str(), "constructor");
+            return false;
+        }
+        else if (argTyped->getMemoryQualifier().writeonly)
+        {
+            error(line, "cannot convert a variable with writeonly", "constructor");
+            return false;
+        }
+        if (argTyped->getBasicType() == EbtVoid)
+        {
+            error(line, "cannot convert a void", "constructor");
+            return false;
+        }
+    }
+
+    if (type.isArray())
+    {
+        // The size of an unsized constructor should already have been determined.
+        ASSERT(!type.isUnsizedArray());
+        if (static_cast<size_t>(type.getOutermostArraySize()) != arguments.size())
+        {
+            error(line, "array constructor needs one argument per array element", "constructor");
+            return false;
+        }
+        // GLSL ES 3.00 section 5.4.4: Each argument must be the same type as the element type of
+        // the array.
+        for (TIntermNode *const &argNode : arguments)
+        {
+            const TType &argType = argNode->getAsTyped()->getType();
+            if (mShaderVersion < 310 && argType.isArray())
+            {
+                error(line, "constructing from a non-dereferenced array", "constructor");
+                return false;
+            }
+            if (!argType.isElementTypeOf(type))
+            {
+                error(line, "Array constructor argument has an incorrect type", "constructor");
+                return false;
+            }
+        }
+    }
+    else if (type.getBasicType() == EbtStruct)
+    {
+        const TFieldList &fields = type.getStruct()->fields();
+        if (fields.size() != arguments.size())
+        {
+            error(line,
+                  "Number of constructor parameters does not match the number of structure fields",
+                  "constructor");
+            return false;
+        }
+
+        for (size_t i = 0; i < fields.size(); i++)
+        {
+            if (i >= arguments.size() ||
+                arguments[i]->getAsTyped()->getType() != *fields[i]->type())
+            {
+                error(line, "Structure constructor arguments do not match structure fields",
+                      "constructor");
+                return false;
+            }
+        }
+    }
+    else
+    {
+        // We're constructing a scalar, vector, or matrix.
+
+        // Note: It's okay to have too many components available, but not okay to have unused
+        // arguments. 'full' will go to true when enough args have been seen. If we loop again,
+        // there is an extra argument, so 'overFull' will become true.
+
+        size_t size    = 0;
+        bool full      = false;
+        bool overFull  = false;
+        bool matrixArg = false;
+        for (TIntermNode *arg : arguments)
+        {
+            const TIntermTyped *argTyped = arg->getAsTyped();
+            ASSERT(argTyped != nullptr);
+
+            if (argTyped->getBasicType() == EbtStruct)
+            {
+                error(line, "a struct cannot be used as a constructor argument for this type",
+                      "constructor");
+                return false;
+            }
+            if (argTyped->getType().isArray())
+            {
+                error(line, "constructing from a non-dereferenced array", "constructor");
+                return false;
+            }
+            if (argTyped->getType().isMatrix())
+            {
+                matrixArg = true;
+            }
+
+            size += argTyped->getType().getObjectSize();
+            if (full)
+            {
+                overFull = true;
+            }
+            if (size >= type.getObjectSize())
+            {
+                full = true;
+            }
+        }
+
+        if (type.isMatrix() && matrixArg)
+        {
+            if (arguments.size() != 1)
+            {
+                error(line, "constructing matrix from matrix can only take one argument",
+                      "constructor");
+                return false;
+            }
+        }
+        else
+        {
+            if (size != 1 && size < type.getObjectSize())
+            {
+                error(line, "not enough data provided for construction", "constructor");
+                return false;
+            }
+            if (overFull)
+            {
+                error(line, "too many arguments", "constructor");
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+// This function checks to see if a void variable has been declared and raise an error message for
+// such a case
+//
+// returns true in case of an error
+//
+bool TParseContext::checkIsNonVoid(const TSourceLoc &line,
+                                   const ImmutableString &identifier,
+                                   const TBasicType &type)
+{
+    if (type == EbtVoid)
+    {
+        error(line, "illegal use of type 'void'", identifier);
+        return false;
+    }
+
+    return true;
+}
+
+// This function checks to see if the node (for the expression) contains a scalar boolean expression
+// or not.
+bool TParseContext::checkIsScalarBool(const TSourceLoc &line, const TIntermTyped *type)
+{
+    if (type->getBasicType() != EbtBool || !type->isScalar())
+    {
+        error(line, "boolean expression expected", "");
+        return false;
+    }
+    return true;
+}
+
+// This function checks to see if the node (for the expression) contains a scalar boolean expression
+// or not.
+void TParseContext::checkIsScalarBool(const TSourceLoc &line, const TPublicType &pType)
+{
+    if (pType.getBasicType() != EbtBool || pType.isAggregate())
+    {
+        error(line, "boolean expression expected", "");
+    }
+}
+
+bool TParseContext::checkIsNotOpaqueType(const TSourceLoc &line,
+                                         const TTypeSpecifierNonArray &pType,
+                                         const char *reason)
+{
+    if (pType.type == EbtStruct)
+    {
+        if (ContainsSampler(pType.userDef))
+        {
+            std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
+            reasonStream << reason << " (structure contains a sampler)";
+            std::string reasonStr = reasonStream.str();
+            error(line, reasonStr.c_str(), getBasicString(pType.type));
+            return false;
+        }
+        // only samplers need to be checked from structs, since other opaque types can't be struct
+        // members.
+        return true;
+    }
+    else if (IsOpaqueType(pType.type))
+    {
+        error(line, reason, getBasicString(pType.type));
+        return false;
+    }
+
+    return true;
+}
+
+void TParseContext::checkDeclaratorLocationIsNotSpecified(const TSourceLoc &line,
+                                                          const TPublicType &pType)
+{
+    if (pType.layoutQualifier.location != -1)
+    {
+        error(line, "location must only be specified for a single input or output variable",
+              "location");
+    }
+}
+
+void TParseContext::checkLocationIsNotSpecified(const TSourceLoc &location,
+                                                const TLayoutQualifier &layoutQualifier)
+{
+    if (layoutQualifier.location != -1)
+    {
+        const char *errorMsg = "invalid layout qualifier: only valid on program inputs and outputs";
+        if (mShaderVersion >= 310)
+        {
+            errorMsg =
+                "invalid layout qualifier: only valid on shader inputs, outputs, and uniforms";
+        }
+        error(location, errorMsg, "location");
+    }
+}
+
+void TParseContext::checkStd430IsForShaderStorageBlock(const TSourceLoc &location,
+                                                       const TLayoutBlockStorage &blockStorage,
+                                                       const TQualifier &qualifier)
+{
+    if (blockStorage == EbsStd430 && qualifier != EvqBuffer)
+    {
+        error(location, "The std430 layout is supported only for shader storage blocks.", "std430");
+    }
+}
+
+void TParseContext::checkOutParameterIsNotOpaqueType(const TSourceLoc &line,
+                                                     TQualifier qualifier,
+                                                     const TType &type)
+{
+    ASSERT(qualifier == EvqParamOut || qualifier == EvqParamInOut);
+    if (IsOpaqueType(type.getBasicType()))
+    {
+        error(line, "opaque types cannot be output parameters", type.getBasicString());
+    }
+}
+
+// Do size checking for an array type's size.
+unsigned int TParseContext::checkIsValidArraySize(const TSourceLoc &line, TIntermTyped *expr)
+{
+    TIntermConstantUnion *constant = expr->getAsConstantUnion();
+
+    // ANGLE should be able to fold any EvqConst expressions resulting in an integer - but to be
+    // safe against corner cases we still check for constant folding. Some interpretations of the
+    // spec have allowed constant expressions with side effects - like array length() method on a
+    // non-constant array.
+    if (expr->getQualifier() != EvqConst || constant == nullptr || !constant->isScalarInt())
+    {
+        error(line, "array size must be a constant integer expression", "");
+        return 1u;
+    }
+
+    unsigned int size = 0u;
+
+    if (constant->getBasicType() == EbtUInt)
+    {
+        size = constant->getUConst(0);
+    }
+    else
+    {
+        int signedSize = constant->getIConst(0);
+
+        if (signedSize < 0)
+        {
+            error(line, "array size must be non-negative", "");
+            return 1u;
+        }
+
+        size = static_cast<unsigned int>(signedSize);
+    }
+
+    if (size == 0u)
+    {
+        error(line, "array size must be greater than zero", "");
+        return 1u;
+    }
+
+    if (IsOutputHLSL(getOutputType()))
+    {
+        // The size of arrays is restricted here to prevent issues further down the
+        // compiler/translator/driver stack. Shader Model 5 generation hardware is limited to
+        // 4096 registers so this should be reasonable even for aggressively optimizable code.
+        const unsigned int sizeLimit = 65536;
+
+        if (size > sizeLimit)
+        {
+            error(line, "array size too large", "");
+            return 1u;
+        }
+    }
+
+    return size;
+}
+
+// See if this qualifier can be an array.
+bool TParseContext::checkIsValidQualifierForArray(const TSourceLoc &line,
+                                                  const TPublicType &elementQualifier)
+{
+    if ((elementQualifier.qualifier == EvqAttribute) ||
+        (elementQualifier.qualifier == EvqVertexIn) ||
+        (elementQualifier.qualifier == EvqConst && mShaderVersion < 300))
+    {
+        error(line, "cannot declare arrays of this qualifier",
+              TType(elementQualifier).getQualifierString());
+        return false;
+    }
+
+    return true;
+}
+
+// See if this element type can be formed into an array.
+bool TParseContext::checkArrayElementIsNotArray(const TSourceLoc &line,
+                                                const TPublicType &elementType)
+{
+    if (mShaderVersion < 310 && elementType.isArray())
+    {
+        TInfoSinkBase typeString;
+        typeString << TType(elementType);
+        error(line, "cannot declare arrays of arrays", typeString.c_str());
+        return false;
+    }
+    return true;
+}
+
+// Check for array-of-arrays being used as non-allowed shader inputs/outputs.
+bool TParseContext::checkArrayOfArraysInOut(const TSourceLoc &line,
+                                            const TPublicType &elementType,
+                                            const TType &arrayType)
+{
+    if (arrayType.isArrayOfArrays())
+    {
+        if (elementType.qualifier == EvqVertexOut)
+        {
+            error(line, "vertex shader output cannot be an array of arrays",
+                  TType(elementType).getQualifierString());
+            return false;
+        }
+        if (elementType.qualifier == EvqFragmentIn)
+        {
+            error(line, "fragment shader input cannot be an array of arrays",
+                  TType(elementType).getQualifierString());
+            return false;
+        }
+        if (elementType.qualifier == EvqFragmentOut || elementType.qualifier == EvqFragmentInOut)
+        {
+            error(line, "fragment shader output cannot be an array of arrays",
+                  TType(elementType).getQualifierString());
+            return false;
+        }
+    }
+    return true;
+}
+
+// Check if this qualified element type can be formed into an array. This is only called when array
+// brackets are associated with an identifier in a declaration, like this:
+//   float a[2];
+// Similar checks are done in addFullySpecifiedType for array declarations where the array brackets
+// are associated with the type, like this:
+//   float[2] a;
+bool TParseContext::checkIsValidTypeAndQualifierForArray(const TSourceLoc &indexLocation,
+                                                         const TPublicType &elementType)
+{
+    if (!checkArrayElementIsNotArray(indexLocation, elementType))
+    {
+        return false;
+    }
+    // In ESSL1.00 shaders, structs cannot be varying (section 4.3.5). This is checked elsewhere.
+    // In ESSL3.00 shaders, struct inputs/outputs are allowed but not arrays of structs (section
+    // 4.3.4).
+    // Geometry shader requires each user-defined input be declared as arrays or inside input
+    // blocks declared as arrays (GL_EXT_geometry_shader section 11.1gs.4.3). For the purposes of
+    // interface matching, such variables and blocks are treated as though they were not declared
+    // as arrays (GL_EXT_geometry_shader section 7.4.1).
+    if (mShaderVersion >= 300 && elementType.getBasicType() == EbtStruct &&
+        sh::IsVarying(elementType.qualifier) &&
+        !IsGeometryShaderInput(mShaderType, elementType.qualifier) &&
+        !IsTessellationControlShaderInput(mShaderType, elementType.qualifier) &&
+        !IsTessellationEvaluationShaderInput(mShaderType, elementType.qualifier) &&
+        !IsTessellationControlShaderOutput(mShaderType, elementType.qualifier))
+    {
+        TInfoSinkBase typeString;
+        typeString << TType(elementType);
+        error(indexLocation, "cannot declare arrays of structs of this qualifier",
+              typeString.c_str());
+        return false;
+    }
+    return checkIsValidQualifierForArray(indexLocation, elementType);
+}
+
+// Enforce non-initializer type/qualifier rules.
+void TParseContext::checkCanBeDeclaredWithoutInitializer(const TSourceLoc &line,
+                                                         const ImmutableString &identifier,
+                                                         TType *type)
+{
+    ASSERT(type != nullptr);
+    if (type->getQualifier() == EvqConst)
+    {
+        // Make the qualifier make sense.
+        type->setQualifier(EvqTemporary);
+
+        // Generate informative error messages for ESSL1.
+        // In ESSL3 arrays and structures containing arrays can be constant.
+        if (mShaderVersion < 300 && type->isStructureContainingArrays())
+        {
+            error(line,
+                  "structures containing arrays may not be declared constant since they cannot be "
+                  "initialized",
+                  identifier);
+        }
+        else
+        {
+            error(line, "variables with qualifier 'const' must be initialized", identifier);
+        }
+    }
+
+    // Implicitly declared arrays are only allowed with tessellation or geometry shader inputs
+    if (type->isArray() &&
+        ((mShaderType != GL_TESS_CONTROL_SHADER && mShaderType != GL_TESS_EVALUATION_SHADER &&
+          mShaderType != GL_GEOMETRY_SHADER) ||
+         (mShaderType == GL_GEOMETRY_SHADER && type->getQualifier() == EvqGeometryOut)))
+    {
+        const TSpan<const unsigned int> &arraySizes = type->getArraySizes();
+        for (unsigned int size : arraySizes)
+        {
+            if (size == 0)
+            {
+                error(line,
+                      "implicitly sized arrays only allowed for tessellation shaders "
+                      "or geometry shader inputs",
+                      identifier);
+            }
+        }
+    }
+}
+
+// Do some simple checks that are shared between all variable declarations,
+// and update the symbol table.
+//
+// Returns true if declaring the variable succeeded.
+//
+bool TParseContext::declareVariable(const TSourceLoc &line,
+                                    const ImmutableString &identifier,
+                                    const TType *type,
+                                    TVariable **variable)
+{
+    ASSERT((*variable) == nullptr);
+
+    SymbolType symbolType = SymbolType::UserDefined;
+    switch (type->getQualifier())
+    {
+        case EvqClipDistance:
+        case EvqCullDistance:
+        case EvqLastFragData:
+            symbolType = SymbolType::BuiltIn;
+            break;
+        default:
+            break;
+    }
+
+    (*variable) = new TVariable(&symbolTable, identifier, type, symbolType);
+
+    ASSERT(type->getLayoutQualifier().index == -1 ||
+           (isExtensionEnabled(TExtension::EXT_blend_func_extended) &&
+            mShaderType == GL_FRAGMENT_SHADER && mShaderVersion >= 300));
+    if (type->getQualifier() == EvqFragmentOut)
+    {
+        if (type->getLayoutQualifier().index != -1 && type->getLayoutQualifier().location == -1)
+        {
+            error(line,
+                  "If index layout qualifier is specified for a fragment output, location must "
+                  "also be specified.",
+                  "index");
+            return false;
+        }
+    }
+    else
+    {
+        checkIndexIsNotSpecified(line, type->getLayoutQualifier().index);
+    }
+
+    if (!((identifier.beginsWith("gl_LastFragData") || type->getQualifier() == EvqFragmentInOut) &&
+          (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch) ||
+           isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent))))
+    {
+        checkNoncoherentIsNotSpecified(line, type->getLayoutQualifier().noncoherent);
+    }
+    else if (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent) &&
+             !isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch))
+    {
+        checkNoncoherentIsSpecified(line, type->getLayoutQualifier().noncoherent);
+    }
+
+    checkBindingIsValid(line, *type);
+
+    bool needsReservedCheck = true;
+
+    // gl_LastFragData may be redeclared with a new precision qualifier
+    if (type->isArray() && identifier.beginsWith("gl_LastFragData"))
+    {
+        const TVariable *maxDrawBuffers = static_cast<const TVariable *>(
+            symbolTable.findBuiltIn(ImmutableString("gl_MaxDrawBuffers"), mShaderVersion));
+        if (type->isArrayOfArrays())
+        {
+            error(line, "redeclaration of gl_LastFragData as an array of arrays", identifier);
+            return false;
+        }
+        else if (static_cast<int>(type->getOutermostArraySize()) ==
+                 maxDrawBuffers->getConstPointer()->getIConst())
+        {
+            if (const TSymbol *builtInSymbol = symbolTable.findBuiltIn(identifier, mShaderVersion))
+            {
+                needsReservedCheck = !checkCanUseOneOfExtensions(line, builtInSymbol->extensions());
+            }
+        }
+        else
+        {
+            error(line, "redeclaration of gl_LastFragData with size != gl_MaxDrawBuffers",
+                  identifier);
+            return false;
+        }
+    }
+    else if (type->isArray() && identifier == "gl_ClipDistance")
+    {
+        // gl_ClipDistance can be redeclared with smaller size than gl_MaxClipDistances
+        const TVariable *maxClipDistances = static_cast<const TVariable *>(
+            symbolTable.findBuiltIn(ImmutableString("gl_MaxClipDistances"), mShaderVersion));
+        if (!maxClipDistances)
+        {
+            // Unsupported extension
+            needsReservedCheck = true;
+        }
+        else if (type->isArrayOfArrays())
+        {
+            error(line, "redeclaration of gl_ClipDistance as an array of arrays", identifier);
+            return false;
+        }
+        else if (static_cast<int>(type->getOutermostArraySize()) <=
+                 maxClipDistances->getConstPointer()->getIConst())
+        {
+            const TSymbol *builtInSymbol = symbolTable.findBuiltIn(identifier, mShaderVersion);
+            if (builtInSymbol)
+            {
+                needsReservedCheck = !checkCanUseOneOfExtensions(line, builtInSymbol->extensions());
+            }
+        }
+        else
+        {
+            error(line, "redeclaration of gl_ClipDistance with size > gl_MaxClipDistances",
+                  identifier);
+            return false;
+        }
+    }
+    else if (type->isArray() && identifier == "gl_CullDistance")
+    {
+        // gl_CullDistance can be redeclared with smaller size than gl_MaxCullDistances
+        const TVariable *maxCullDistances = static_cast<const TVariable *>(
+            symbolTable.findBuiltIn(ImmutableString("gl_MaxCullDistances"), mShaderVersion));
+        if (!maxCullDistances)
+        {
+            // Unsupported extension
+            needsReservedCheck = true;
+        }
+        else if (type->isArrayOfArrays())
+        {
+            error(line, "redeclaration of gl_CullDistance as an array of arrays", identifier);
+            return false;
+        }
+        else if (static_cast<int>(type->getOutermostArraySize()) <=
+                 maxCullDistances->getConstPointer()->getIConst())
+        {
+            if (const TSymbol *builtInSymbol = symbolTable.findBuiltIn(identifier, mShaderVersion))
+            {
+                needsReservedCheck = !checkCanUseOneOfExtensions(line, builtInSymbol->extensions());
+            }
+        }
+        else
+        {
+            error(line, "redeclaration of gl_CullDistance with size > gl_MaxCullDistances",
+                  identifier);
+            return false;
+        }
+    }
+
+    if (needsReservedCheck && !checkIsNotReserved(line, identifier))
+        return false;
+
+    if (!symbolTable.declare(*variable))
+    {
+        error(line, "redefinition", identifier);
+        return false;
+    }
+
+    if (!checkIsNonVoid(line, identifier, type->getBasicType()))
+        return false;
+
+    return true;
+}
+
+void TParseContext::checkIsParameterQualifierValid(
+    const TSourceLoc &line,
+    const TTypeQualifierBuilder &typeQualifierBuilder,
+    TType *type)
+{
+    // The only parameter qualifiers a parameter can have are in, out, inout or const.
+    TTypeQualifier typeQualifier =
+        typeQualifierBuilder.getParameterTypeQualifier(type->getBasicType(), mDiagnostics);
+
+    if (typeQualifier.qualifier == EvqParamOut || typeQualifier.qualifier == EvqParamInOut)
+    {
+        checkOutParameterIsNotOpaqueType(line, typeQualifier.qualifier, *type);
+    }
+
+    if (!IsImage(type->getBasicType()))
+    {
+        checkMemoryQualifierIsNotSpecified(typeQualifier.memoryQualifier, line);
+    }
+    else
+    {
+        type->setMemoryQualifier(typeQualifier.memoryQualifier);
+    }
+
+    type->setQualifier(typeQualifier.qualifier);
+
+    if (typeQualifier.precision != EbpUndefined)
+    {
+        type->setPrecision(typeQualifier.precision);
+    }
+
+    if (typeQualifier.precise)
+    {
+        type->setPrecise(true);
+    }
+}
+
+template <size_t size>
+bool TParseContext::checkCanUseOneOfExtensions(const TSourceLoc &line,
+                                               const std::array<TExtension, size> &extensions)
+{
+    ASSERT(!extensions.empty());
+    const TExtensionBehavior &extBehavior = extensionBehavior();
+
+    bool canUseWithWarning    = false;
+    bool canUseWithoutWarning = false;
+
+    const char *errorMsgString   = "";
+    TExtension errorMsgExtension = TExtension::UNDEFINED;
+
+    for (TExtension extension : extensions)
+    {
+        auto extIter = extBehavior.find(extension);
+        if (canUseWithWarning)
+        {
+            // We already have an extension that we can use, but with a warning.
+            // See if we can use the alternative extension without a warning.
+            if (extIter == extBehavior.end())
+            {
+                continue;
+            }
+            if (extIter->second == EBhEnable || extIter->second == EBhRequire)
+            {
+                canUseWithoutWarning = true;
+                break;
+            }
+            continue;
+        }
+        if (extension == TExtension::UNDEFINED)
+        {
+            continue;
+        }
+        else if (extIter == extBehavior.end())
+        {
+            errorMsgString    = "extension is not supported";
+            errorMsgExtension = extension;
+        }
+        else if (extIter->second == EBhUndefined || extIter->second == EBhDisable)
+        {
+            errorMsgString    = "extension is disabled";
+            errorMsgExtension = extension;
+        }
+        else if (extIter->second == EBhWarn)
+        {
+            errorMsgExtension = extension;
+            canUseWithWarning = true;
+        }
+        else
+        {
+            ASSERT(extIter->second == EBhEnable || extIter->second == EBhRequire);
+            canUseWithoutWarning = true;
+            break;
+        }
+    }
+
+    if (canUseWithoutWarning)
+    {
+        return true;
+    }
+    if (canUseWithWarning)
+    {
+        warning(line, "extension is being used", GetExtensionNameString(errorMsgExtension));
+        return true;
+    }
+    error(line, errorMsgString, GetExtensionNameString(errorMsgExtension));
+    return false;
+}
+
+template bool TParseContext::checkCanUseOneOfExtensions(
+    const TSourceLoc &line,
+    const std::array<TExtension, 1> &extensions);
+template bool TParseContext::checkCanUseOneOfExtensions(
+    const TSourceLoc &line,
+    const std::array<TExtension, 2> &extensions);
+template bool TParseContext::checkCanUseOneOfExtensions(
+    const TSourceLoc &line,
+    const std::array<TExtension, 3> &extensions);
+
+bool TParseContext::checkCanUseExtension(const TSourceLoc &line, TExtension extension)
+{
+    ASSERT(extension != TExtension::UNDEFINED);
+    return checkCanUseOneOfExtensions(line, std::array<TExtension, 1u>{{extension}});
+}
+
+// ESSL 3.00.6 section 4.8 Empty Declarations: "The combinations of qualifiers that cause
+// compile-time or link-time errors are the same whether or not the declaration is empty".
+// This function implements all the checks that are done on qualifiers regardless of if the
+// declaration is empty.
+void TParseContext::declarationQualifierErrorCheck(const sh::TQualifier qualifier,
+                                                   const sh::TLayoutQualifier &layoutQualifier,
+                                                   const TSourceLoc &location)
+{
+    if (qualifier == EvqShared && !layoutQualifier.isEmpty())
+    {
+        error(location, "Shared memory declarations cannot have layout specified", "layout");
+    }
+
+    if (layoutQualifier.matrixPacking != EmpUnspecified)
+    {
+        error(location, "layout qualifier only valid for interface blocks",
+              getMatrixPackingString(layoutQualifier.matrixPacking));
+        return;
+    }
+
+    if (layoutQualifier.blockStorage != EbsUnspecified)
+    {
+        error(location, "layout qualifier only valid for interface blocks",
+              getBlockStorageString(layoutQualifier.blockStorage));
+        return;
+    }
+
+    if (qualifier == EvqFragmentOut)
+    {
+        if (layoutQualifier.location != -1 && layoutQualifier.yuv == true)
+        {
+            error(location, "invalid layout qualifier combination", "yuv");
+            return;
+        }
+    }
+    else
+    {
+        checkYuvIsNotSpecified(location, layoutQualifier.yuv);
+    }
+
+    if (qualifier != EvqFragmentIn)
+    {
+        checkEarlyFragmentTestsIsNotSpecified(location, layoutQualifier.earlyFragmentTests);
+    }
+
+    // If multiview extension is enabled, "in" qualifier is allowed in the vertex shader in previous
+    // parsing steps. So it needs to be checked here.
+    if (anyMultiviewExtensionAvailable() && mShaderVersion < 300 && qualifier == EvqVertexIn)
+    {
+        error(location, "storage qualifier supported in GLSL ES 3.00 and above only", "in");
+    }
+
+    bool canHaveLocation = qualifier == EvqVertexIn || qualifier == EvqFragmentOut;
+    if (mShaderVersion >= 300 &&
+        (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch) ||
+         isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent)))
+    {
+        // In the case of EXT_shader_framebuffer_fetch or EXT_shader_framebuffer_fetch_non_coherent
+        // extension, the location of inout qualifier is used to set the input attachment index
+        canHaveLocation = canHaveLocation || qualifier == EvqFragmentInOut;
+    }
+    if (mShaderVersion >= 310)
+    {
+        canHaveLocation = canHaveLocation || qualifier == EvqUniform || IsVarying(qualifier);
+        // We're not checking whether the uniform location is in range here since that depends on
+        // the type of the variable.
+        // The type can only be fully determined for non-empty declarations.
+    }
+    if (!canHaveLocation)
+    {
+        checkLocationIsNotSpecified(location, layoutQualifier);
+    }
+}
+
+void TParseContext::atomicCounterQualifierErrorCheck(const TPublicType &publicType,
+                                                     const TSourceLoc &location)
+{
+    if (publicType.precision != EbpHigh)
+    {
+        error(location, "Can only be highp", "atomic counter");
+    }
+    // dEQP enforces compile error if location is specified. See uniform_location.test.
+    if (publicType.layoutQualifier.location != -1)
+    {
+        error(location, "location must not be set for atomic_uint", "layout");
+    }
+    if (publicType.layoutQualifier.binding == -1)
+    {
+        error(location, "no binding specified", "atomic counter");
+    }
+}
+
+void TParseContext::emptyDeclarationErrorCheck(const TType &type, const TSourceLoc &location)
+{
+    if (type.isUnsizedArray())
+    {
+        // ESSL3 spec section 4.1.9: Array declaration which leaves the size unspecified is an
+        // error. It is assumed that this applies to empty declarations as well.
+        error(location, "empty array declaration needs to specify a size", "");
+    }
+
+    if (type.getQualifier() != EvqFragmentOut)
+    {
+        checkIndexIsNotSpecified(location, type.getLayoutQualifier().index);
+    }
+}
+
+// These checks are done for all declarations that are non-empty. They're done for non-empty
+// declarations starting a declarator list, and declarators that follow an empty declaration.
+void TParseContext::nonEmptyDeclarationErrorCheck(const TPublicType &publicType,
+                                                  const TSourceLoc &identifierLocation)
+{
+    switch (publicType.qualifier)
+    {
+        case EvqVaryingIn:
+        case EvqVaryingOut:
+        case EvqAttribute:
+        case EvqVertexIn:
+        case EvqFragmentOut:
+        case EvqFragmentInOut:
+        case EvqComputeIn:
+            if (publicType.getBasicType() == EbtStruct)
+            {
+                error(identifierLocation, "cannot be used with a structure",
+                      getQualifierString(publicType.qualifier));
+                return;
+            }
+            break;
+        case EvqBuffer:
+            if (publicType.getBasicType() != EbtInterfaceBlock)
+            {
+                error(identifierLocation,
+                      "cannot declare buffer variables at global scope(outside a block)",
+                      getQualifierString(publicType.qualifier));
+                return;
+            }
+            break;
+        default:
+            break;
+    }
+    std::string reason(getBasicString(publicType.getBasicType()));
+    reason += "s must be uniform";
+    if (publicType.qualifier != EvqUniform &&
+        !checkIsNotOpaqueType(identifierLocation, publicType.typeSpecifierNonArray, reason.c_str()))
+    {
+        return;
+    }
+
+    if ((publicType.qualifier != EvqTemporary && publicType.qualifier != EvqGlobal &&
+         publicType.qualifier != EvqConst) &&
+        publicType.getBasicType() == EbtYuvCscStandardEXT)
+    {
+        error(identifierLocation, "cannot be used with a yuvCscStandardEXT",
+              getQualifierString(publicType.qualifier));
+        return;
+    }
+
+    if (mShaderVersion >= 310 && publicType.qualifier == EvqUniform)
+    {
+        // Valid uniform declarations can't be unsized arrays since uniforms can't be initialized.
+        // But invalid shaders may still reach here with an unsized array declaration.
+        TType type(publicType);
+        if (!type.isUnsizedArray())
+        {
+            checkUniformLocationInRange(identifierLocation, type.getLocationCount(),
+                                        publicType.layoutQualifier);
+        }
+    }
+
+    if (mShaderVersion >= 300 && publicType.qualifier == EvqVertexIn)
+    {
+        // Valid vertex input declarations can't be unsized arrays since they can't be initialized.
+        // But invalid shaders may still reach here with an unsized array declaration.
+        TType type(publicType);
+        if (!type.isUnsizedArray())
+        {
+            checkAttributeLocationInRange(identifierLocation, type.getLocationCount(),
+                                          publicType.layoutQualifier);
+        }
+    }
+
+    // check for layout qualifier issues
+    const TLayoutQualifier layoutQualifier = publicType.layoutQualifier;
+
+    if (IsImage(publicType.getBasicType()))
+    {
+
+        switch (layoutQualifier.imageInternalFormat)
+        {
+            case EiifRGBA32F:
+            case EiifRGBA16F:
+            case EiifR32F:
+            case EiifRGBA8:
+            case EiifRGBA8_SNORM:
+                if (!IsFloatImage(publicType.getBasicType()))
+                {
+                    error(identifierLocation,
+                          "internal image format requires a floating image type",
+                          getBasicString(publicType.getBasicType()));
+                    return;
+                }
+                break;
+            case EiifRGBA32I:
+            case EiifRGBA16I:
+            case EiifRGBA8I:
+            case EiifR32I:
+                if (!IsIntegerImage(publicType.getBasicType()))
+                {
+                    error(identifierLocation,
+                          "internal image format requires an integer image type",
+                          getBasicString(publicType.getBasicType()));
+                    return;
+                }
+                break;
+            case EiifRGBA32UI:
+            case EiifRGBA16UI:
+            case EiifRGBA8UI:
+            case EiifR32UI:
+                if (!IsUnsignedImage(publicType.getBasicType()))
+                {
+                    error(identifierLocation,
+                          "internal image format requires an unsigned image type",
+                          getBasicString(publicType.getBasicType()));
+                    return;
+                }
+                break;
+            case EiifUnspecified:
+                error(identifierLocation, "layout qualifier", "No image internal format specified");
+                return;
+            default:
+                error(identifierLocation, "layout qualifier", "unrecognized token");
+                return;
+        }
+
+        // GLSL ES 3.10 Revision 4, 4.9 Memory Access Qualifiers
+        switch (layoutQualifier.imageInternalFormat)
+        {
+            case EiifR32F:
+            case EiifR32I:
+            case EiifR32UI:
+                break;
+            default:
+                if (!publicType.memoryQualifier.readonly && !publicType.memoryQualifier.writeonly)
+                {
+                    error(identifierLocation, "layout qualifier",
+                          "Except for images with the r32f, r32i and r32ui format qualifiers, "
+                          "image variables must be qualified readonly and/or writeonly");
+                    return;
+                }
+                break;
+        }
+    }
+    else if (IsPixelLocal(publicType.getBasicType()))
+    {
+        if (getShaderType() != GL_FRAGMENT_SHADER)
+        {
+            error(identifierLocation,
+                  "undefined use of pixel local storage outside a fragment shader",
+                  getBasicString(publicType.getBasicType()));
+            return;
+        }
+        switch (layoutQualifier.imageInternalFormat)
+        {
+            case EiifR32F:
+            case EiifRGBA8:
+                if (publicType.getBasicType() != EbtPixelLocalANGLE)
+                {
+                    error(identifierLocation, "pixel local storage format requires pixelLocalANGLE",
+                          getImageInternalFormatString(layoutQualifier.imageInternalFormat));
+                }
+                break;
+            case EiifRGBA8I:
+                if (publicType.getBasicType() != EbtIPixelLocalANGLE)
+                {
+                    error(identifierLocation,
+                          "pixel local storage format requires ipixelLocalANGLE",
+                          getImageInternalFormatString(layoutQualifier.imageInternalFormat));
+                }
+                break;
+            case EiifR32UI:
+            case EiifRGBA8UI:
+                if (publicType.getBasicType() != EbtUPixelLocalANGLE)
+                {
+                    error(identifierLocation,
+                          "pixel local storage format requires upixelLocalANGLE",
+                          getImageInternalFormatString(layoutQualifier.imageInternalFormat));
+                }
+                break;
+            case EiifR32I:
+            case EiifRGBA8_SNORM:
+            case EiifRGBA16F:
+            case EiifRGBA32F:
+            case EiifRGBA16I:
+            case EiifRGBA32I:
+            case EiifRGBA16UI:
+            case EiifRGBA32UI:
+            default:
+                ASSERT(!IsValidWithPixelLocalStorage(layoutQualifier.imageInternalFormat));
+                error(identifierLocation, "illegal pixel local storage format",
+                      getImageInternalFormatString(layoutQualifier.imageInternalFormat));
+                break;
+            case EiifUnspecified:
+                error(identifierLocation, "pixel local storage requires a format specifier",
+                      "layout qualifier");
+                break;
+        }
+        checkMemoryQualifierIsNotSpecified(publicType.memoryQualifier, identifierLocation);
+        checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);
+    }
+    else
+    {
+        checkInternalFormatIsNotSpecified(identifierLocation, layoutQualifier.imageInternalFormat);
+        checkMemoryQualifierIsNotSpecified(publicType.memoryQualifier, identifierLocation);
+    }
+
+    if (IsAtomicCounter(publicType.getBasicType()))
+    {
+        atomicCounterQualifierErrorCheck(publicType, identifierLocation);
+    }
+    else
+    {
+        checkOffsetIsNotSpecified(identifierLocation, layoutQualifier.offset);
+    }
+}
+
+void TParseContext::checkBindingIsValid(const TSourceLoc &identifierLocation, const TType &type)
+{
+    TLayoutQualifier layoutQualifier = type.getLayoutQualifier();
+    // Note that the ESSL 3.10 section 4.4.5 is not particularly clear on how the binding qualifier
+    // on arrays of arrays should be handled. We interpret the spec so that the binding value is
+    // incremented for each element of the innermost nested arrays. This is in line with how arrays
+    // of arrays of blocks are specified to behave in GLSL 4.50 and a conservative interpretation
+    // when it comes to which shaders are accepted by the compiler.
+    int arrayTotalElementCount = type.getArraySizeProduct();
+    if (IsPixelLocal(type.getBasicType()))
+    {
+        checkPixelLocalStorageBindingIsValid(identifierLocation, type);
+    }
+    else if (mShaderVersion < 310)
+    {
+        checkBindingIsNotSpecified(identifierLocation, layoutQualifier.binding);
+    }
+    else if (IsImage(type.getBasicType()))
+    {
+        checkImageBindingIsValid(identifierLocation, layoutQualifier.binding,
+                                 arrayTotalElementCount);
+    }
+    else if (IsSampler(type.getBasicType()))
+    {
+        checkSamplerBindingIsValid(identifierLocation, layoutQualifier.binding,
+                                   arrayTotalElementCount);
+    }
+    else if (IsAtomicCounter(type.getBasicType()))
+    {
+        checkAtomicCounterBindingIsValid(identifierLocation, layoutQualifier.binding);
+    }
+    else
+    {
+        ASSERT(!IsOpaqueType(type.getBasicType()));
+        checkBindingIsNotSpecified(identifierLocation, layoutQualifier.binding);
+    }
+}
+
+void TParseContext::checkCanUseLayoutQualifier(const TSourceLoc &location)
+{
+    constexpr std::array<TExtension, 4u> extensions{
+        {TExtension::EXT_shader_framebuffer_fetch,
+         TExtension::EXT_shader_framebuffer_fetch_non_coherent,
+         TExtension::KHR_blend_equation_advanced, TExtension::ANGLE_shader_pixel_local_storage}};
+    if (getShaderVersion() < 300 && !checkCanUseOneOfExtensions(location, extensions))
+    {
+        error(location, "qualifier supported in GLSL ES 3.00 and above only", "layout");
+    }
+}
+
+bool TParseContext::checkLayoutQualifierSupported(const TSourceLoc &location,
+                                                  const ImmutableString &layoutQualifierName,
+                                                  int versionRequired)
+{
+
+    if (mShaderVersion < versionRequired)
+    {
+        error(location, "invalid layout qualifier: not supported", layoutQualifierName);
+        return false;
+    }
+    return true;
+}
+
+bool TParseContext::checkWorkGroupSizeIsNotSpecified(const TSourceLoc &location,
+                                                     const TLayoutQualifier &layoutQualifier)
+{
+    const sh::WorkGroupSize &localSize = layoutQualifier.localSize;
+    for (size_t i = 0u; i < localSize.size(); ++i)
+    {
+        if (localSize[i] != -1)
+        {
+            error(location,
+                  "invalid layout qualifier: only valid when used with 'in' in a compute shader "
+                  "global layout declaration",
+                  getWorkGroupSizeString(i));
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void TParseContext::checkInternalFormatIsNotSpecified(const TSourceLoc &location,
+                                                      TLayoutImageInternalFormat internalFormat)
+{
+    if (internalFormat != EiifUnspecified)
+    {
+        if (mShaderVersion < 310)
+        {
+            if (IsValidWithPixelLocalStorage(internalFormat))
+            {
+                error(location,
+                      "invalid layout qualifier: not supported before GLSL ES 3.10, except pixel "
+                      "local storage",
+                      getImageInternalFormatString(internalFormat));
+            }
+            else
+            {
+                error(location, "invalid layout qualifier: not supported before GLSL ES 3.10",
+                      getImageInternalFormatString(internalFormat));
+            }
+        }
+        else
+        {
+            if (IsValidWithPixelLocalStorage(internalFormat))
+            {
+                error(location,
+                      "invalid layout qualifier: only valid when used with images or pixel local "
+                      "storage ",
+                      getImageInternalFormatString(internalFormat));
+            }
+            else
+            {
+                error(location, "invalid layout qualifier: only valid when used with images",
+                      getImageInternalFormatString(internalFormat));
+            }
+        }
+    }
+}
+
+void TParseContext::checkIndexIsNotSpecified(const TSourceLoc &location, int index)
+{
+    if (index != -1)
+    {
+        error(location,
+              "invalid layout qualifier: only valid when used with a fragment shader output in "
+              "ESSL version >= 3.00 and EXT_blend_func_extended is enabled",
+              "index");
+    }
+}
+
+void TParseContext::checkBindingIsNotSpecified(const TSourceLoc &location, int binding)
+{
+    if (binding != -1)
+    {
+        if (mShaderVersion < 310)
+        {
+            error(location,
+                  "invalid layout qualifier: only valid when used with pixel local storage",
+                  "binding");
+        }
+        else
+        {
+            error(location,
+                  "invalid layout qualifier: only valid when used with opaque types or blocks",
+                  "binding");
+        }
+    }
+}
+
+void TParseContext::checkOffsetIsNotSpecified(const TSourceLoc &location, int offset)
+{
+    if (offset != -1)
+    {
+        error(location, "invalid layout qualifier: only valid when used with atomic counters",
+              "offset");
+    }
+}
+
+void TParseContext::checkImageBindingIsValid(const TSourceLoc &location,
+                                             int binding,
+                                             int arrayTotalElementCount)
+{
+    // Expects arraySize to be 1 when setting binding for only a single variable.
+    if (binding >= 0 && binding + arrayTotalElementCount > mMaxImageUnits)
+    {
+        error(location, "image binding greater than gl_MaxImageUnits", "binding");
+    }
+}
+
+void TParseContext::checkSamplerBindingIsValid(const TSourceLoc &location,
+                                               int binding,
+                                               int arrayTotalElementCount)
+{
+    // Expects arraySize to be 1 when setting binding for only a single variable.
+    if (binding >= 0 && binding + arrayTotalElementCount > mMaxCombinedTextureImageUnits)
+    {
+        error(location, "sampler binding greater than maximum texture units", "binding");
+    }
+}
+
+void TParseContext::checkBlockBindingIsValid(const TSourceLoc &location,
+                                             const TQualifier &qualifier,
+                                             int binding,
+                                             int arraySize)
+{
+    int size = (arraySize == 0 ? 1 : arraySize);
+    if (qualifier == EvqUniform)
+    {
+        if (binding + size > mMaxUniformBufferBindings)
+        {
+            error(location, "uniform block binding greater than MAX_UNIFORM_BUFFER_BINDINGS",
+                  "binding");
+        }
+    }
+    else if (qualifier == EvqBuffer)
+    {
+        if (binding + size > mMaxShaderStorageBufferBindings)
+        {
+            error(location,
+                  "shader storage block binding greater than MAX_SHADER_STORAGE_BUFFER_BINDINGS",
+                  "binding");
+        }
+    }
+}
+void TParseContext::checkAtomicCounterBindingIsValid(const TSourceLoc &location, int binding)
+{
+    if (binding >= mMaxAtomicCounterBindings)
+    {
+        error(location, "atomic counter binding greater than gl_MaxAtomicCounterBindings",
+              "binding");
+    }
+}
+
+void TParseContext::checkPixelLocalStorageBindingIsValid(const TSourceLoc &location,
+                                                         const TType &type)
+{
+    TLayoutQualifier layoutQualifier = type.getLayoutQualifier();
+    if (type.isArray())
+    {
+        // PLS is not allowed in arrays.
+        // TODO(anglebug.com/7279): Consider allowing this once more backends are implemented.
+        error(location, "pixel local storage handles cannot be aggregated in arrays", "array");
+    }
+    else if (layoutQualifier.binding < 0)
+    {
+        error(location, "pixel local storage requires a binding index", "layout qualifier");
+    }
+    // TODO(anglebug.com/7279):
+    // else if (binding >= GL_MAX_LOCAL_STORAGE_PLANES_ANGLE)
+    // {
+    // }
+    else if (mPLSBindings.find(layoutQualifier.binding) != mPLSBindings.end())
+    {
+        error(location, "duplicate pixel local storage binding index",
+              std::to_string(layoutQualifier.binding).c_str());
+    }
+    else
+    {
+        mPLSBindings[layoutQualifier.binding] = layoutQualifier.imageInternalFormat;
+        // "mPLSBindings" is how we know whether pixel local storage uniforms have been declared, so
+        // flush the queue of potential errors once mPLSBindings isn't empty.
+        if (!mPLSPotentialErrors.empty())
+        {
+            for (const auto &[loc, op] : mPLSPotentialErrors)
+            {
+                errorIfPLSDeclared(loc, op);
+            }
+            mPLSPotentialErrors.clear();
+        }
+    }
+}
+
+void TParseContext::checkUniformLocationInRange(const TSourceLoc &location,
+                                                int objectLocationCount,
+                                                const TLayoutQualifier &layoutQualifier)
+{
+    int loc = layoutQualifier.location;
+    if (loc >= 0)  // Shader-specified location
+    {
+        if (loc >= mMaxUniformLocations || objectLocationCount > mMaxUniformLocations ||
+            static_cast<unsigned int>(loc) + static_cast<unsigned int>(objectLocationCount) >
+                static_cast<unsigned int>(mMaxUniformLocations))
+        {
+            error(location, "Uniform location out of range", "location");
+        }
+    }
+}
+
+void TParseContext::checkAttributeLocationInRange(const TSourceLoc &location,
+                                                  int objectLocationCount,
+                                                  const TLayoutQualifier &layoutQualifier)
+{
+    int loc = layoutQualifier.location;
+    if (loc >= 0)  // Shader-specified location
+    {
+        if (loc >= mMaxVertexAttribs || objectLocationCount > mMaxVertexAttribs ||
+            static_cast<unsigned int>(loc) + static_cast<unsigned int>(objectLocationCount) >
+                static_cast<unsigned int>(mMaxVertexAttribs))
+        {
+            error(location, "Attribute location out of range", "location");
+        }
+    }
+}
+
+void TParseContext::checkYuvIsNotSpecified(const TSourceLoc &location, bool yuv)
+{
+    if (yuv != false)
+    {
+        error(location, "invalid layout qualifier: only valid on program outputs", "yuv");
+    }
+}
+
+void TParseContext::checkEarlyFragmentTestsIsNotSpecified(const TSourceLoc &location,
+                                                          bool earlyFragmentTests)
+{
+    if (earlyFragmentTests != false)
+    {
+        error(location,
+              "invalid layout qualifier: only valid when used with 'in' in a fragment shader",
+              "early_fragment_tests");
+    }
+}
+
+void TParseContext::checkNoncoherentIsSpecified(const TSourceLoc &location, bool noncoherent)
+{
+    if (noncoherent == false)
+    {
+        error(location,
+              "'noncoherent' qualifier must be used when "
+              "GL_EXT_shader_framebuffer_fetch_non_coherent extension is used",
+              "noncoherent");
+    }
+}
+
+void TParseContext::checkNoncoherentIsNotSpecified(const TSourceLoc &location, bool noncoherent)
+{
+    if (noncoherent != false)
+    {
+        error(location,
+              "invalid layout qualifier: only valid when used with 'gl_LastFragData' or the "
+              "variable decorated with 'inout' in a fragment shader",
+              "noncoherent");
+    }
+}
+
+void TParseContext::checkTCSOutVarIndexIsValid(TIntermBinary *binaryExpression,
+                                               const TSourceLoc &location)
+{
+    ASSERT(binaryExpression->getOp() == EOpIndexIndirect ||
+           binaryExpression->getOp() == EOpIndexDirect);
+    const TIntermSymbol *intermSymbol = binaryExpression->getRight()->getAsSymbolNode();
+    if ((intermSymbol == nullptr) || (intermSymbol->getName() != "gl_InvocationID"))
+    {
+        error(location,
+              "tessellation-control per-vertex output l-value must be indexed with "
+              "gl_InvocationID",
+              "[");
+    }
+}
+
+void TParseContext::functionCallRValueLValueErrorCheck(const TFunction *fnCandidate,
+                                                       TIntermAggregate *fnCall)
+{
+    for (size_t i = 0; i < fnCandidate->getParamCount(); ++i)
+    {
+        TQualifier qual        = fnCandidate->getParam(i)->getType().getQualifier();
+        TIntermTyped *argument = (*(fnCall->getSequence()))[i]->getAsTyped();
+        bool argumentIsRead    = (IsQualifierUnspecified(qual) || qual == EvqParamIn ||
+                               qual == EvqParamInOut || qual == EvqParamConst);
+        if (argumentIsRead)
+        {
+            markStaticReadIfSymbol(argument);
+            if (!IsImage(argument->getBasicType()))
+            {
+                if (argument->getMemoryQualifier().writeonly)
+                {
+                    error(argument->getLine(),
+                          "Writeonly value cannot be passed for 'in' or 'inout' parameters.",
+                          fnCall->functionName());
+                    return;
+                }
+            }
+        }
+        if (qual == EvqParamOut || qual == EvqParamInOut)
+        {
+            if (!checkCanBeLValue(argument->getLine(), "assign", argument))
+            {
+                error(argument->getLine(),
+                      "Constant value cannot be passed for 'out' or 'inout' parameters.",
+                      fnCall->functionName());
+                return;
+            }
+        }
+    }
+}
+
+void TParseContext::checkInvariantVariableQualifier(bool invariant,
+                                                    const TQualifier qualifier,
+                                                    const TSourceLoc &invariantLocation)
+{
+    if (!invariant)
+        return;
+
+    if (mShaderVersion < 300)
+    {
+        // input variables in the fragment shader can be also qualified as invariant
+        if (!sh::CanBeInvariantESSL1(qualifier))
+        {
+            error(invariantLocation, "Cannot be qualified as invariant.", "invariant");
+        }
+    }
+    else
+    {
+        if (!sh::CanBeInvariantESSL3OrGreater(qualifier))
+        {
+            error(invariantLocation, "Cannot be qualified as invariant.", "invariant");
+        }
+    }
+}
+
+void TParseContext::checkAdvancedBlendEquationsNotSpecified(
+    const TSourceLoc &location,
+    const AdvancedBlendEquations &advancedBlendEquations,
+    const TQualifier &qualifier)
+{
+    if (advancedBlendEquations.any() && qualifier != EvqFragmentOut)
+    {
+        error(location,
+              "invalid layout qualifier: blending equation qualifiers are only permitted on the "
+              "fragment 'out' qualifier ",
+              "blend_support_qualifier");
+    }
+}
+
+bool TParseContext::isExtensionEnabled(TExtension extension) const
+{
+    return IsExtensionEnabled(extensionBehavior(), extension);
+}
+
+void TParseContext::handleExtensionDirective(const TSourceLoc &loc,
+                                             const char *extName,
+                                             const char *behavior)
+{
+    angle::pp::SourceLocation srcLoc;
+    srcLoc.file = loc.first_file;
+    srcLoc.line = loc.first_line;
+    mDirectiveHandler.handleExtension(srcLoc, extName, behavior);
+}
+
+void TParseContext::handlePragmaDirective(const TSourceLoc &loc,
+                                          const char *name,
+                                          const char *value,
+                                          bool stdgl)
+{
+    angle::pp::SourceLocation srcLoc;
+    srcLoc.file = loc.first_file;
+    srcLoc.line = loc.first_line;
+    mDirectiveHandler.handlePragma(srcLoc, name, value, stdgl);
+}
+
+sh::WorkGroupSize TParseContext::getComputeShaderLocalSize() const
+{
+    sh::WorkGroupSize result(-1);
+    for (size_t i = 0u; i < result.size(); ++i)
+    {
+        if (mComputeShaderLocalSizeDeclared && mComputeShaderLocalSize[i] == -1)
+        {
+            result[i] = 1;
+        }
+        else
+        {
+            result[i] = mComputeShaderLocalSize[i];
+        }
+    }
+    return result;
+}
+
+TIntermConstantUnion *TParseContext::addScalarLiteral(const TConstantUnion *constantUnion,
+                                                      const TSourceLoc &line)
+{
+    TIntermConstantUnion *node = new TIntermConstantUnion(
+        constantUnion, TType(constantUnion->getType(), EbpUndefined, EvqConst));
+    node->setLine(line);
+    return node;
+}
+
+/////////////////////////////////////////////////////////////////////////////////
+//
+// Non-Errors.
+//
+/////////////////////////////////////////////////////////////////////////////////
+
+const TVariable *TParseContext::getNamedVariable(const TSourceLoc &location,
+                                                 const ImmutableString &name,
+                                                 const TSymbol *symbol)
+{
+    if (!symbol)
+    {
+        error(location, "undeclared identifier", name);
+        return nullptr;
+    }
+
+    if (!symbol->isVariable())
+    {
+        error(location, "variable expected", name);
+        return nullptr;
+    }
+
+    const TVariable *variable = static_cast<const TVariable *>(symbol);
+
+    if (!variable->extensions().empty() && variable->extensions()[0] != TExtension::UNDEFINED)
+    {
+        checkCanUseOneOfExtensions(location, variable->extensions());
+    }
+
+    // GLSL ES 3.1 Revision 4, 7.1.3 Compute Shader Special Variables
+    if (getShaderType() == GL_COMPUTE_SHADER && !mComputeShaderLocalSizeDeclared &&
+        variable->getType().getQualifier() == EvqWorkGroupSize)
+    {
+        error(location,
+              "It is an error to use gl_WorkGroupSize before declaring the local group size",
+              "gl_WorkGroupSize");
+    }
+
+    // If EXT_shader_framebuffer_fetch_non_coherent is used, gl_LastFragData should be decorated
+    // with 'layout(noncoherent)' EXT_shader_framebuffer_fetch_non_coherent spec: "Unless the
+    // GL_EXT_shader_framebuffer_fetch extension  has been enabled in addition, it's an error to use
+    // gl_LastFragData if it hasn't been explicitly redeclared with layout(noncoherent)."
+    if (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent) &&
+        !isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch) &&
+        variable->getType().getQualifier() == EvqLastFragData)
+    {
+        checkNoncoherentIsSpecified(location, variable->getType().getLayoutQualifier().noncoherent);
+    }
+    return variable;
+}
+
+TIntermTyped *TParseContext::parseVariableIdentifier(const TSourceLoc &location,
+                                                     const ImmutableString &name,
+                                                     const TSymbol *symbol)
+{
+    const TVariable *variable = getNamedVariable(location, name, symbol);
+
+    if (!variable)
+    {
+        TIntermTyped *node = CreateZeroNode(TType(EbtFloat, EbpHigh, EvqConst));
+        node->setLine(location);
+        return node;
+    }
+
+    const TType &variableType = variable->getType();
+    TIntermTyped *node        = nullptr;
+
+    if (variable->getConstPointer() && variableType.canReplaceWithConstantUnion())
+    {
+        const TConstantUnion *constArray = variable->getConstPointer();
+        node                             = new TIntermConstantUnion(constArray, variableType);
+    }
+    else if (variableType.getQualifier() == EvqWorkGroupSize && mComputeShaderLocalSizeDeclared)
+    {
+        // gl_WorkGroupSize can be used to size arrays according to the ESSL 3.10.4 spec, so it
+        // needs to be added to the AST as a constant and not as a symbol.
+        sh::WorkGroupSize workGroupSize = getComputeShaderLocalSize();
+        TConstantUnion *constArray      = new TConstantUnion[3];
+        for (size_t i = 0; i < 3; ++i)
+        {
+            constArray[i].setUConst(static_cast<unsigned int>(workGroupSize[i]));
+        }
+
+        ASSERT(variableType.getBasicType() == EbtUInt);
+        ASSERT(variableType.getObjectSize() == 3);
+
+        TType type(variableType);
+        type.setQualifier(EvqConst);
+        node = new TIntermConstantUnion(constArray, type);
+    }
+    else if ((mGeometryShaderInputPrimitiveType != EptUndefined) &&
+             (variableType.getQualifier() == EvqPerVertexIn))
+    {
+        ASSERT(symbolTable.getGlInVariableWithArraySize() != nullptr);
+        node = new TIntermSymbol(symbolTable.getGlInVariableWithArraySize());
+    }
+    else
+    {
+        node = new TIntermSymbol(variable);
+    }
+    ASSERT(node != nullptr);
+    node->setLine(location);
+    return node;
+}
+
+void TParseContext::adjustRedeclaredBuiltInType(const ImmutableString &identifier, TType *type)
+{
+    if (identifier == "gl_ClipDistance")
+    {
+        type->setQualifier(EvqClipDistance);
+    }
+    else if (identifier == "gl_CullDistance")
+    {
+        type->setQualifier(EvqCullDistance);
+    }
+    else if (identifier == "gl_LastFragData")
+    {
+        type->setQualifier(EvqLastFragData);
+    }
+}
+
+// Initializers show up in several places in the grammar.  Have one set of
+// code to handle them here.
+//
+// Returns true on success.
+bool TParseContext::executeInitializer(const TSourceLoc &line,
+                                       const ImmutableString &identifier,
+                                       TType *type,
+                                       TIntermTyped *initializer,
+                                       TIntermBinary **initNode)
+{
+    ASSERT(initNode != nullptr);
+    ASSERT(*initNode == nullptr);
+
+    if (type->isUnsizedArray())
+    {
+        // In case initializer is not an array or type has more dimensions than initializer, this
+        // will default to setting array sizes to 1. We have not checked yet whether the initializer
+        // actually is an array or not. Having a non-array initializer for an unsized array will
+        // result in an error later, so we don't generate an error message here.
+        type->sizeUnsizedArrays(initializer->getType().getArraySizes());
+    }
+
+    const TQualifier qualifier = type->getQualifier();
+
+    bool constError = false;
+    if (qualifier == EvqConst)
+    {
+        if (EvqConst != initializer->getType().getQualifier())
+        {
+            TInfoSinkBase reasonStream;
+            reasonStream << "assigning non-constant to '" << *type << "'";
+            error(line, reasonStream.c_str(), "=");
+
+            // We're still going to declare the variable to avoid extra error messages.
+            type->setQualifier(EvqTemporary);
+            constError = true;
+        }
+    }
+
+    TVariable *variable = nullptr;
+    if (!declareVariable(line, identifier, type, &variable))
+    {
+        return false;
+    }
+
+    if (constError)
+    {
+        return false;
+    }
+
+    bool nonConstGlobalInitializers =
+        IsExtensionEnabled(mDirectiveHandler.extensionBehavior(),
+                           TExtension::EXT_shader_non_constant_global_initializers);
+    bool globalInitWarning = false;
+    if (symbolTable.atGlobalLevel() &&
+        !ValidateGlobalInitializer(initializer, mShaderVersion, sh::IsWebGLBasedSpec(mShaderSpec),
+                                   nonConstGlobalInitializers, &globalInitWarning))
+    {
+        // Error message does not completely match behavior with ESSL 1.00, but
+        // we want to steer developers towards only using constant expressions.
+        error(line, "global variable initializers must be constant expressions", "=");
+        return false;
+    }
+    if (globalInitWarning)
+    {
+        warning(
+            line,
+            "global variable initializers should be constant expressions "
+            "(uniforms and globals are allowed in global initializers for legacy compatibility)",
+            "=");
+    }
+
+    // identifier must be of type constant, a global, or a temporary
+    if ((qualifier != EvqTemporary) && (qualifier != EvqGlobal) && (qualifier != EvqConst))
+    {
+        error(line, " cannot initialize this type of qualifier ",
+              variable->getType().getQualifierString());
+        return false;
+    }
+
+    TIntermSymbol *intermSymbol = new TIntermSymbol(variable);
+    intermSymbol->setLine(line);
+
+    if (!binaryOpCommonCheck(EOpInitialize, intermSymbol, initializer, line))
+    {
+        assignError(line, "=", variable->getType(), initializer->getType());
+        return false;
+    }
+
+    if (qualifier == EvqConst)
+    {
+        // Save the constant folded value to the variable if possible.
+        const TConstantUnion *constArray = initializer->getConstantValue();
+        if (constArray)
+        {
+            variable->shareConstPointer(constArray);
+            if (initializer->getType().canReplaceWithConstantUnion())
+            {
+                ASSERT(*initNode == nullptr);
+                return true;
+            }
+        }
+    }
+
+    *initNode = new TIntermBinary(EOpInitialize, intermSymbol, initializer);
+    markStaticReadIfSymbol(initializer);
+    (*initNode)->setLine(line);
+    return true;
+}
+
+TIntermNode *TParseContext::addConditionInitializer(const TPublicType &pType,
+                                                    const ImmutableString &identifier,
+                                                    TIntermTyped *initializer,
+                                                    const TSourceLoc &loc)
+{
+    checkIsScalarBool(loc, pType);
+    TIntermBinary *initNode = nullptr;
+    TType *type             = new TType(pType);
+    if (executeInitializer(loc, identifier, type, initializer, &initNode))
+    {
+        // The initializer is valid. The init condition needs to have a node - either the
+        // initializer node, or a constant node in case the initialized variable is const and won't
+        // be recorded in the AST.
+        if (initNode == nullptr)
+        {
+            return initializer;
+        }
+        else
+        {
+            TIntermDeclaration *declaration = new TIntermDeclaration();
+            declaration->appendDeclarator(initNode);
+            return declaration;
+        }
+    }
+    return nullptr;
+}
+
+TIntermNode *TParseContext::addLoop(TLoopType type,
+                                    TIntermNode *init,
+                                    TIntermNode *cond,
+                                    TIntermTyped *expr,
+                                    TIntermNode *body,
+                                    const TSourceLoc &line)
+{
+    TIntermNode *node       = nullptr;
+    TIntermTyped *typedCond = nullptr;
+    if (cond)
+    {
+        markStaticReadIfSymbol(cond);
+        typedCond = cond->getAsTyped();
+    }
+    if (expr)
+    {
+        markStaticReadIfSymbol(expr);
+    }
+    // In case the loop body was not parsed as a block and contains a statement that simply refers
+    // to a variable, we need to mark it as statically used.
+    if (body)
+    {
+        markStaticReadIfSymbol(body);
+    }
+    if (cond == nullptr || typedCond)
+    {
+        if (type == ELoopDoWhile && typedCond)
+        {
+            checkIsScalarBool(line, typedCond);
+        }
+        // In the case of other loops, it was checked before that the condition is a scalar boolean.
+        ASSERT(mDiagnostics->numErrors() > 0 || typedCond == nullptr ||
+               (typedCond->getBasicType() == EbtBool && !typedCond->isArray() &&
+                !typedCond->isVector()));
+
+        node = new TIntermLoop(type, init, typedCond, expr, EnsureBlock(body));
+        node->setLine(line);
+        return node;
+    }
+
+    ASSERT(type != ELoopDoWhile);
+
+    TIntermDeclaration *declaration = cond->getAsDeclarationNode();
+    ASSERT(declaration);
+    TIntermBinary *declarator = declaration->getSequence()->front()->getAsBinaryNode();
+    ASSERT(declarator->getLeft()->getAsSymbolNode());
+
+    // The condition is a declaration. In the AST representation we don't support declarations as
+    // loop conditions. Wrap the loop to a block that declares the condition variable and contains
+    // the loop.
+    TIntermBlock *block = new TIntermBlock();
+
+    TIntermDeclaration *declareCondition = new TIntermDeclaration();
+    declareCondition->appendDeclarator(declarator->getLeft()->deepCopy());
+    block->appendStatement(declareCondition);
+
+    TIntermBinary *conditionInit = new TIntermBinary(EOpAssign, declarator->getLeft()->deepCopy(),
+                                                     declarator->getRight()->deepCopy());
+    TIntermLoop *loop = new TIntermLoop(type, init, conditionInit, expr, EnsureBlock(body));
+    block->appendStatement(loop);
+    loop->setLine(line);
+    block->setLine(line);
+    return block;
+}
+
+TIntermNode *TParseContext::addIfElse(TIntermTyped *cond,
+                                      TIntermNodePair code,
+                                      const TSourceLoc &loc)
+{
+    bool isScalarBool = checkIsScalarBool(loc, cond);
+    // In case the conditional statements were not parsed as blocks and contain a statement that
+    // simply refers to a variable, we need to mark them as statically used.
+    if (code.node1)
+    {
+        markStaticReadIfSymbol(code.node1);
+    }
+    if (code.node2)
+    {
+        markStaticReadIfSymbol(code.node2);
+    }
+
+    // For compile time constant conditions, prune the code now.
+    if (isScalarBool && cond->getAsConstantUnion())
+    {
+        if (cond->getAsConstantUnion()->getBConst(0) == true)
+        {
+            return EnsureBlock(code.node1);
+        }
+        else
+        {
+            return EnsureBlock(code.node2);
+        }
+    }
+
+    TIntermIfElse *node = new TIntermIfElse(cond, EnsureBlock(code.node1), EnsureBlock(code.node2));
+    markStaticReadIfSymbol(cond);
+    node->setLine(loc);
+
+    return node;
+}
+
+void TParseContext::addFullySpecifiedType(TPublicType *typeSpecifier)
+{
+    checkPrecisionSpecified(typeSpecifier->getLine(), typeSpecifier->precision,
+                            typeSpecifier->getBasicType());
+
+    if (mShaderVersion < 300 && typeSpecifier->isArray())
+    {
+        error(typeSpecifier->getLine(), "not supported", "first-class array");
+        typeSpecifier->clearArrayness();
+    }
+}
+
+TPublicType TParseContext::addFullySpecifiedType(const TTypeQualifierBuilder &typeQualifierBuilder,
+                                                 const TPublicType &typeSpecifier)
+{
+    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);
+
+    TPublicType returnType     = typeSpecifier;
+    returnType.qualifier       = typeQualifier.qualifier;
+    returnType.invariant       = typeQualifier.invariant;
+    returnType.precise         = typeQualifier.precise;
+    returnType.layoutQualifier = typeQualifier.layoutQualifier;
+    returnType.memoryQualifier = typeQualifier.memoryQualifier;
+    returnType.precision       = typeSpecifier.precision;
+
+    if (typeQualifier.precision != EbpUndefined)
+    {
+        returnType.precision = typeQualifier.precision;
+    }
+
+    checkPrecisionSpecified(typeSpecifier.getLine(), returnType.precision,
+                            typeSpecifier.getBasicType());
+
+    checkInvariantVariableQualifier(returnType.invariant, returnType.qualifier,
+                                    typeSpecifier.getLine());
+
+    checkWorkGroupSizeIsNotSpecified(typeSpecifier.getLine(), returnType.layoutQualifier);
+
+    checkEarlyFragmentTestsIsNotSpecified(typeSpecifier.getLine(),
+                                          returnType.layoutQualifier.earlyFragmentTests);
+
+    if (returnType.qualifier == EvqSampleIn || returnType.qualifier == EvqSampleOut)
+    {
+        mSampleQualifierSpecified = true;
+    }
+
+    if (mShaderVersion < 300)
+    {
+        if (typeSpecifier.isArray())
+        {
+            error(typeSpecifier.getLine(), "not supported", "first-class array");
+            returnType.clearArrayness();
+        }
+
+        if (returnType.qualifier == EvqAttribute &&
+            (typeSpecifier.getBasicType() == EbtBool || typeSpecifier.getBasicType() == EbtInt))
+        {
+            error(typeSpecifier.getLine(), "cannot be bool or int",
+                  getQualifierString(returnType.qualifier));
+        }
+
+        if ((returnType.qualifier == EvqVaryingIn || returnType.qualifier == EvqVaryingOut) &&
+            (typeSpecifier.getBasicType() == EbtBool || typeSpecifier.getBasicType() == EbtInt))
+        {
+            error(typeSpecifier.getLine(), "cannot be bool or int",
+                  getQualifierString(returnType.qualifier));
+        }
+    }
+    else
+    {
+        if (!returnType.layoutQualifier.isEmpty())
+        {
+            checkIsAtGlobalLevel(typeSpecifier.getLine(), "layout");
+        }
+        if (sh::IsVarying(returnType.qualifier) || returnType.qualifier == EvqVertexIn ||
+            returnType.qualifier == EvqFragmentOut || returnType.qualifier == EvqFragmentInOut)
+        {
+            checkInputOutputTypeIsValidES3(returnType.qualifier, typeSpecifier,
+                                           typeSpecifier.getLine());
+        }
+        if (returnType.qualifier == EvqComputeIn)
+        {
+            error(typeSpecifier.getLine(), "'in' can be only used to specify the local group size",
+                  "in");
+        }
+    }
+
+    return returnType;
+}
+
+void TParseContext::checkInputOutputTypeIsValidES3(const TQualifier qualifier,
+                                                   const TPublicType &type,
+                                                   const TSourceLoc &qualifierLocation)
+{
+    // An input/output variable can never be bool or a sampler. Samplers are checked elsewhere.
+    if (type.getBasicType() == EbtBool)
+    {
+        error(qualifierLocation, "cannot be bool", getQualifierString(qualifier));
+    }
+
+    // Specific restrictions apply for vertex shader inputs and fragment shader outputs.
+    switch (qualifier)
+    {
+        case EvqVertexIn:
+            // ESSL 3.00 section 4.3.4
+            if (type.isArray())
+            {
+                error(qualifierLocation, "cannot be array", getQualifierString(qualifier));
+            }
+            // Vertex inputs with a struct type are disallowed in nonEmptyDeclarationErrorCheck
+            return;
+        case EvqFragmentOut:
+        case EvqFragmentInOut:
+            // ESSL 3.00 section 4.3.6
+            if (type.typeSpecifierNonArray.isMatrix())
+            {
+                error(qualifierLocation, "cannot be matrix", getQualifierString(qualifier));
+            }
+            // Fragment outputs with a struct type are disallowed in nonEmptyDeclarationErrorCheck
+            return;
+        default:
+            break;
+    }
+
+    // Vertex shader outputs / fragment shader inputs have a different, slightly more lenient set of
+    // restrictions.
+    bool typeContainsIntegers =
+        (type.getBasicType() == EbtInt || type.getBasicType() == EbtUInt ||
+         type.isStructureContainingType(EbtInt) || type.isStructureContainingType(EbtUInt));
+    bool extendedShaderTypes = mShaderVersion >= 320 ||
+                               isExtensionEnabled(TExtension::EXT_geometry_shader) ||
+                               isExtensionEnabled(TExtension::OES_geometry_shader) ||
+                               isExtensionEnabled(TExtension::EXT_tessellation_shader);
+    if (typeContainsIntegers && qualifier != EvqFlatIn && qualifier != EvqFlatOut &&
+        (!extendedShaderTypes || mShaderType == GL_FRAGMENT_SHADER))
+    {
+        error(qualifierLocation, "must use 'flat' interpolation here",
+              getQualifierString(qualifier));
+    }
+
+    if (type.getBasicType() == EbtStruct)
+    {
+        // ESSL 3.00 sections 4.3.4 and 4.3.6.
+        // These restrictions are only implied by the ESSL 3.00 spec, but
+        // the ESSL 3.10 spec lists these restrictions explicitly.
+        if (type.isArray())
+        {
+            error(qualifierLocation, "cannot be an array of structures",
+                  getQualifierString(qualifier));
+        }
+        if (type.isStructureContainingArrays())
+        {
+            error(qualifierLocation, "cannot be a structure containing an array",
+                  getQualifierString(qualifier));
+        }
+        if (type.isStructureContainingType(EbtStruct))
+        {
+            error(qualifierLocation, "cannot be a structure containing a structure",
+                  getQualifierString(qualifier));
+        }
+        if (type.isStructureContainingType(EbtBool))
+        {
+            error(qualifierLocation, "cannot be a structure containing a bool",
+                  getQualifierString(qualifier));
+        }
+    }
+}
+
+void TParseContext::checkLocalVariableConstStorageQualifier(const TQualifierWrapperBase &qualifier)
+{
+    if (qualifier.getType() == QtStorage)
+    {
+        const TStorageQualifierWrapper &storageQualifier =
+            static_cast<const TStorageQualifierWrapper &>(qualifier);
+        if (!declaringFunction() && storageQualifier.getQualifier() != EvqConst &&
+            !symbolTable.atGlobalLevel())
+        {
+            error(storageQualifier.getLine(),
+                  "Local variables can only use the const storage qualifier.",
+                  storageQualifier.getQualifierString());
+        }
+    }
+}
+
+void TParseContext::checkMemoryQualifierIsNotSpecified(const TMemoryQualifier &memoryQualifier,
+                                                       const TSourceLoc &location)
+{
+    const std::string reason(
+        "Only allowed with shader storage blocks, variables declared within shader storage blocks "
+        "and variables declared as image types.");
+    if (memoryQualifier.readonly)
+    {
+        error(location, reason.c_str(), "readonly");
+    }
+    if (memoryQualifier.writeonly)
+    {
+        error(location, reason.c_str(), "writeonly");
+    }
+    if (memoryQualifier.coherent)
+    {
+        error(location, reason.c_str(), "coherent");
+    }
+    if (memoryQualifier.restrictQualifier)
+    {
+        error(location, reason.c_str(), "restrict");
+    }
+    if (memoryQualifier.volatileQualifier)
+    {
+        error(location, reason.c_str(), "volatile");
+    }
+}
+
+// Make sure there is no offset overlapping, and store the newly assigned offset to "type" in
+// intermediate tree.
+void TParseContext::checkAtomicCounterOffsetDoesNotOverlap(bool forceAppend,
+                                                           const TSourceLoc &loc,
+                                                           TType *type)
+{
+    const size_t size = type->isArray() ? kAtomicCounterArrayStride * type->getArraySizeProduct()
+                                        : kAtomicCounterSize;
+    TLayoutQualifier layoutQualifier = type->getLayoutQualifier();
+    auto &bindingState               = mAtomicCounterBindingStates[layoutQualifier.binding];
+    int offset;
+    if (layoutQualifier.offset == -1 || forceAppend)
+    {
+        offset = bindingState.appendSpan(size);
+    }
+    else
+    {
+        offset = bindingState.insertSpan(layoutQualifier.offset, size);
+    }
+    if (offset == -1)
+    {
+        error(loc, "Offset overlapping", "atomic counter");
+        return;
+    }
+    layoutQualifier.offset = offset;
+    type->setLayoutQualifier(layoutQualifier);
+}
+
+void TParseContext::checkAtomicCounterOffsetAlignment(const TSourceLoc &location, const TType &type)
+{
+    TLayoutQualifier layoutQualifier = type.getLayoutQualifier();
+
+    // OpenGL ES 3.1 Table 6.5, Atomic counter offset must be a multiple of 4
+    if (layoutQualifier.offset % 4 != 0)
+    {
+        error(location, "Offset must be multiple of 4", "atomic counter");
+    }
+}
+
+void TParseContext::checkGeometryShaderInputAndSetArraySize(const TSourceLoc &location,
+                                                            const ImmutableString &token,
+                                                            TType *type)
+{
+    if (IsGeometryShaderInput(mShaderType, type->getQualifier()))
+    {
+        if (type->isArray() && type->getOutermostArraySize() == 0u)
+        {
+            // Set size for the unsized geometry shader inputs if they are declared after a valid
+            // input primitive declaration.
+            if (mGeometryShaderInputPrimitiveType != EptUndefined)
+            {
+                ASSERT(symbolTable.getGlInVariableWithArraySize() != nullptr);
+                type->sizeOutermostUnsizedArray(
+                    symbolTable.getGlInVariableWithArraySize()->getType().getOutermostArraySize());
+            }
+            else
+            {
+                // [GLSL ES 3.2 SPEC Chapter 4.4.1.2]
+                // An input can be declared without an array size if there is a previous layout
+                // which specifies the size.
+                warning(location,
+                        "Missing a valid input primitive declaration before declaring an unsized "
+                        "array input",
+                        "Deferred");
+                mDeferredArrayTypesToSize.push_back(type);
+            }
+        }
+        else if (type->isArray())
+        {
+            setGeometryShaderInputArraySize(type->getOutermostArraySize(), location);
+        }
+        else
+        {
+            error(location, "Geometry shader input variable must be declared as an array", token);
+        }
+    }
+}
+
+void TParseContext::checkTessellationShaderUnsizedArraysAndSetSize(const TSourceLoc &location,
+                                                                   const ImmutableString &token,
+                                                                   TType *type)
+{
+    TQualifier qualifier = type->getQualifier();
+    if (!IsTessellationControlShaderOutput(mShaderType, qualifier) &&
+        !IsTessellationControlShaderInput(mShaderType, qualifier) &&
+        !IsTessellationEvaluationShaderInput(mShaderType, qualifier))
+    {
+        return;
+    }
+
+    // Such variables must be declared as arrays or inside output blocks declared as arrays.
+    if (!type->isArray())
+    {
+        error(location, "Tessellation interface variables must be declared as an array", token);
+        return;
+    }
+
+    // If a size is specified, it must match the maximum patch size.
+    unsigned int outermostSize = type->getOutermostArraySize();
+    if (outermostSize == 0u)
+    {
+        switch (qualifier)
+        {
+            case EvqTessControlIn:
+            case EvqTessEvaluationIn:
+            case EvqFlatIn:
+            case EvqCentroidIn:
+            case EvqSmoothIn:
+            case EvqSampleIn:
+                // Declaring an array size is optional. If no size is specified, it will be taken
+                // from the implementation-dependent maximum patch size (gl_MaxPatchVertices).
+                ASSERT(mMaxPatchVertices > 0);
+                type->sizeOutermostUnsizedArray(mMaxPatchVertices);
+                break;
+            case EvqTessControlOut:
+            case EvqFlatOut:
+            case EvqCentroidOut:
+            case EvqSmoothOut:
+            case EvqSampleOut:
+                // Declaring an array size is optional. If no size is specified, it will be taken
+                // from output patch size declared in the shader.  If the patch size is not yet
+                // declared, this is deferred until such time as it does.
+                if (mTessControlShaderOutputVertices == 0)
+                {
+                    mDeferredArrayTypesToSize.push_back(type);
+                }
+                else
+                {
+                    type->sizeOutermostUnsizedArray(mTessControlShaderOutputVertices);
+                }
+                break;
+            default:
+                UNREACHABLE();
+                break;
+        }
+        return;
+    }
+
+    if (IsTessellationControlShaderInput(mShaderType, qualifier) ||
+        IsTessellationEvaluationShaderInput(mShaderType, qualifier))
+    {
+        if (outermostSize != static_cast<unsigned int>(mMaxPatchVertices))
+        {
+            error(location,
+                  "If a size is specified for a tessellation control or evaluation user-defined "
+                  "input variable, it must match the maximum patch size (gl_MaxPatchVertices).",
+                  token);
+        }
+    }
+    else if (IsTessellationControlShaderOutput(mShaderType, qualifier))
+    {
+        if (outermostSize != static_cast<unsigned int>(mTessControlShaderOutputVertices) &&
+            mTessControlShaderOutputVertices != 0)
+        {
+            error(location,
+                  "If a size is specified for a tessellation control user-defined per-vertex "
+                  "output variable, it must match the the number of vertices in the output "
+                  "patch.",
+                  token);
+        }
+    }
+}
+
+TIntermDeclaration *TParseContext::parseSingleDeclaration(
+    TPublicType &publicType,
+    const TSourceLoc &identifierOrTypeLocation,
+    const ImmutableString &identifier)
+{
+    TType *type = new TType(publicType);
+    if (mCompileOptions.flattenPragmaSTDGLInvariantAll &&
+        mDirectiveHandler.pragma().stdgl.invariantAll)
+    {
+        TQualifier qualifier = type->getQualifier();
+
+        // The directive handler has already taken care of rejecting invalid uses of this pragma
+        // (for example, in ESSL 3.00 fragment shaders), so at this point, flatten it into all
+        // affected variable declarations:
+        //
+        // 1. Built-in special variables which are inputs to the fragment shader. (These are handled
+        // elsewhere, in TranslatorGLSL.)
+        //
+        // 2. Outputs from vertex shaders in ESSL 1.00 and 3.00 (EvqVaryingOut and EvqVertexOut). It
+        // is actually less likely that there will be bugs in the handling of ESSL 3.00 shaders, but
+        // the way this is currently implemented we have to enable this compiler option before
+        // parsing the shader and determining the shading language version it uses. If this were
+        // implemented as a post-pass, the workaround could be more targeted.
+        if (qualifier == EvqVaryingOut || qualifier == EvqVertexOut)
+        {
+            type->setInvariant(true);
+        }
+    }
+
+    checkGeometryShaderInputAndSetArraySize(identifierOrTypeLocation, identifier, type);
+    checkTessellationShaderUnsizedArraysAndSetSize(identifierOrTypeLocation, identifier, type);
+
+    declarationQualifierErrorCheck(publicType.qualifier, publicType.layoutQualifier,
+                                   identifierOrTypeLocation);
+
+    bool emptyDeclaration                  = (identifier == "");
+    mDeferredNonEmptyDeclarationErrorCheck = emptyDeclaration;
+
+    TIntermSymbol *symbol = nullptr;
+    if (emptyDeclaration)
+    {
+        emptyDeclarationErrorCheck(*type, identifierOrTypeLocation);
+        // In most cases we don't need to create a symbol node for an empty declaration.
+        // But if the empty declaration is declaring a struct type, the symbol node will store that.
+        if (type->getBasicType() == EbtStruct)
+        {
+            TVariable *emptyVariable =
+                new TVariable(&symbolTable, kEmptyImmutableString, type, SymbolType::Empty);
+            symbol = new TIntermSymbol(emptyVariable);
+        }
+        else if (IsAtomicCounter(publicType.getBasicType()))
+        {
+            setAtomicCounterBindingDefaultOffset(publicType, identifierOrTypeLocation);
+        }
+    }
+    else
+    {
+        nonEmptyDeclarationErrorCheck(publicType, identifierOrTypeLocation);
+
+        checkCanBeDeclaredWithoutInitializer(identifierOrTypeLocation, identifier, type);
+
+        if (IsAtomicCounter(type->getBasicType()))
+        {
+            checkAtomicCounterOffsetDoesNotOverlap(false, identifierOrTypeLocation, type);
+
+            checkAtomicCounterOffsetAlignment(identifierOrTypeLocation, *type);
+        }
+
+        TVariable *variable = nullptr;
+        if (declareVariable(identifierOrTypeLocation, identifier, type, &variable))
+        {
+            symbol = new TIntermSymbol(variable);
+        }
+    }
+
+    TIntermDeclaration *declaration = new TIntermDeclaration();
+    declaration->setLine(identifierOrTypeLocation);
+    if (symbol)
+    {
+        symbol->setLine(identifierOrTypeLocation);
+        declaration->appendDeclarator(symbol);
+    }
+    return declaration;
+}
+
+TIntermDeclaration *TParseContext::parseSingleArrayDeclaration(
+    TPublicType &elementType,
+    const TSourceLoc &identifierLocation,
+    const ImmutableString &identifier,
+    const TSourceLoc &indexLocation,
+    const TVector<unsigned int> &arraySizes)
+{
+    mDeferredNonEmptyDeclarationErrorCheck = false;
+
+    declarationQualifierErrorCheck(elementType.qualifier, elementType.layoutQualifier,
+                                   identifierLocation);
+
+    nonEmptyDeclarationErrorCheck(elementType, identifierLocation);
+
+    checkIsValidTypeAndQualifierForArray(indexLocation, elementType);
+
+    TType *arrayType = new TType(elementType);
+    arrayType->makeArrays(arraySizes);
+
+    checkArrayOfArraysInOut(indexLocation, elementType, *arrayType);
+
+    checkGeometryShaderInputAndSetArraySize(indexLocation, identifier, arrayType);
+    checkTessellationShaderUnsizedArraysAndSetSize(indexLocation, identifier, arrayType);
+
+    checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, arrayType);
+
+    if (IsAtomicCounter(arrayType->getBasicType()))
+    {
+        checkAtomicCounterOffsetDoesNotOverlap(false, identifierLocation, arrayType);
+
+        checkAtomicCounterOffsetAlignment(identifierLocation, *arrayType);
+    }
+
+    adjustRedeclaredBuiltInType(identifier, arrayType);
+
+    TIntermDeclaration *declaration = new TIntermDeclaration();
+    declaration->setLine(identifierLocation);
+
+    TVariable *variable = nullptr;
+    if (declareVariable(identifierLocation, identifier, arrayType, &variable))
+    {
+        TIntermSymbol *symbol = new TIntermSymbol(variable);
+        symbol->setLine(identifierLocation);
+        declaration->appendDeclarator(symbol);
+    }
+
+    return declaration;
+}
+
+TIntermDeclaration *TParseContext::parseSingleInitDeclaration(const TPublicType &publicType,
+                                                              const TSourceLoc &identifierLocation,
+                                                              const ImmutableString &identifier,
+                                                              const TSourceLoc &initLocation,
+                                                              TIntermTyped *initializer)
+{
+    mDeferredNonEmptyDeclarationErrorCheck = false;
+
+    declarationQualifierErrorCheck(publicType.qualifier, publicType.layoutQualifier,
+                                   identifierLocation);
+
+    nonEmptyDeclarationErrorCheck(publicType, identifierLocation);
+
+    TIntermDeclaration *declaration = new TIntermDeclaration();
+    declaration->setLine(identifierLocation);
+
+    TIntermBinary *initNode = nullptr;
+    TType *type             = new TType(publicType);
+    if (executeInitializer(identifierLocation, identifier, type, initializer, &initNode))
+    {
+        if (initNode)
+        {
+            declaration->appendDeclarator(initNode);
+        }
+        else if (publicType.isStructSpecifier())
+        {
+            // The initialization got constant folded.  If it's a struct, declare the struct anyway.
+            TVariable *emptyVariable =
+                new TVariable(&symbolTable, kEmptyImmutableString, type, SymbolType::Empty);
+            TIntermSymbol *symbol = new TIntermSymbol(emptyVariable);
+            symbol->setLine(publicType.getLine());
+            declaration->appendDeclarator(symbol);
+        }
+    }
+    return declaration;
+}
+
+TIntermDeclaration *TParseContext::parseSingleArrayInitDeclaration(
+    TPublicType &elementType,
+    const TSourceLoc &identifierLocation,
+    const ImmutableString &identifier,
+    const TSourceLoc &indexLocation,
+    const TVector<unsigned int> &arraySizes,
+    const TSourceLoc &initLocation,
+    TIntermTyped *initializer)
+{
+    mDeferredNonEmptyDeclarationErrorCheck = false;
+
+    declarationQualifierErrorCheck(elementType.qualifier, elementType.layoutQualifier,
+                                   identifierLocation);
+
+    nonEmptyDeclarationErrorCheck(elementType, identifierLocation);
+
+    checkIsValidTypeAndQualifierForArray(indexLocation, elementType);
+
+    TType *arrayType = new TType(elementType);
+    arrayType->makeArrays(arraySizes);
+
+    TIntermDeclaration *declaration = new TIntermDeclaration();
+    declaration->setLine(identifierLocation);
+
+    // initNode will correspond to the whole of "type b[n] = initializer".
+    TIntermBinary *initNode = nullptr;
+    if (executeInitializer(identifierLocation, identifier, arrayType, initializer, &initNode))
+    {
+        if (initNode)
+        {
+            declaration->appendDeclarator(initNode);
+        }
+    }
+
+    return declaration;
+}
+
+TIntermGlobalQualifierDeclaration *TParseContext::parseGlobalQualifierDeclaration(
+    const TTypeQualifierBuilder &typeQualifierBuilder,
+    const TSourceLoc &identifierLoc,
+    const ImmutableString &identifier,
+    const TSymbol *symbol)
+{
+    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);
+
+    if (!typeQualifier.invariant && !typeQualifier.precise)
+    {
+        error(identifierLoc, "Expected invariant or precise", identifier);
+        return nullptr;
+    }
+    if (typeQualifier.invariant && !checkIsAtGlobalLevel(identifierLoc, "invariant varying"))
+    {
+        return nullptr;
+    }
+    if (!symbol)
+    {
+        error(identifierLoc, "undeclared identifier declared as invariant or precise", identifier);
+        return nullptr;
+    }
+    if (!IsQualifierUnspecified(typeQualifier.qualifier))
+    {
+        error(identifierLoc, "invariant or precise declaration specifies qualifier",
+              getQualifierString(typeQualifier.qualifier));
+    }
+    if (typeQualifier.precision != EbpUndefined)
+    {
+        error(identifierLoc, "invariant or precise declaration specifies precision",
+              getPrecisionString(typeQualifier.precision));
+    }
+    if (!typeQualifier.layoutQualifier.isEmpty())
+    {
+        error(identifierLoc, "invariant or precise declaration specifies layout", "'layout'");
+    }
+
+    const TVariable *variable = getNamedVariable(identifierLoc, identifier, symbol);
+    if (!variable)
+    {
+        return nullptr;
+    }
+    const TType &type = variable->getType();
+
+    checkInvariantVariableQualifier(typeQualifier.invariant, type.getQualifier(),
+                                    typeQualifier.line);
+    checkMemoryQualifierIsNotSpecified(typeQualifier.memoryQualifier, typeQualifier.line);
+
+    symbolTable.addInvariantVarying(*variable);
+
+    TIntermSymbol *intermSymbol = new TIntermSymbol(variable);
+    intermSymbol->setLine(identifierLoc);
+
+    return new TIntermGlobalQualifierDeclaration(intermSymbol, typeQualifier.precise,
+                                                 identifierLoc);
+}
+
+void TParseContext::parseDeclarator(TPublicType &publicType,
+                                    const TSourceLoc &identifierLocation,
+                                    const ImmutableString &identifier,
+                                    TIntermDeclaration *declarationOut)
+{
+    // If the declaration starting this declarator list was empty (example: int,), some checks were
+    // not performed.
+    if (mDeferredNonEmptyDeclarationErrorCheck)
+    {
+        nonEmptyDeclarationErrorCheck(publicType, identifierLocation);
+        mDeferredNonEmptyDeclarationErrorCheck = false;
+    }
+
+    checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);
+
+    TType *type = new TType(publicType);
+
+    checkGeometryShaderInputAndSetArraySize(identifierLocation, identifier, type);
+    checkTessellationShaderUnsizedArraysAndSetSize(identifierLocation, identifier, type);
+
+    checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, type);
+
+    if (IsAtomicCounter(type->getBasicType()))
+    {
+        checkAtomicCounterOffsetDoesNotOverlap(true, identifierLocation, type);
+
+        checkAtomicCounterOffsetAlignment(identifierLocation, *type);
+    }
+
+    adjustRedeclaredBuiltInType(identifier, type);
+
+    TVariable *variable = nullptr;
+    if (declareVariable(identifierLocation, identifier, type, &variable))
+    {
+        TIntermSymbol *symbol = new TIntermSymbol(variable);
+        symbol->setLine(identifierLocation);
+        declarationOut->appendDeclarator(symbol);
+    }
+}
+
+void TParseContext::parseArrayDeclarator(TPublicType &elementType,
+                                         const TSourceLoc &identifierLocation,
+                                         const ImmutableString &identifier,
+                                         const TSourceLoc &arrayLocation,
+                                         const TVector<unsigned int> &arraySizes,
+                                         TIntermDeclaration *declarationOut)
+{
+    // If the declaration starting this declarator list was empty (example: int,), some checks were
+    // not performed.
+    if (mDeferredNonEmptyDeclarationErrorCheck)
+    {
+        nonEmptyDeclarationErrorCheck(elementType, identifierLocation);
+        mDeferredNonEmptyDeclarationErrorCheck = false;
+    }
+
+    checkDeclaratorLocationIsNotSpecified(identifierLocation, elementType);
+
+    if (checkIsValidTypeAndQualifierForArray(arrayLocation, elementType))
+    {
+        TType *arrayType = new TType(elementType);
+        arrayType->makeArrays(arraySizes);
+
+        checkGeometryShaderInputAndSetArraySize(identifierLocation, identifier, arrayType);
+        checkTessellationShaderUnsizedArraysAndSetSize(identifierLocation, identifier, arrayType);
+
+        checkCanBeDeclaredWithoutInitializer(identifierLocation, identifier, arrayType);
+
+        if (IsAtomicCounter(arrayType->getBasicType()))
+        {
+            checkAtomicCounterOffsetDoesNotOverlap(true, identifierLocation, arrayType);
+
+            checkAtomicCounterOffsetAlignment(identifierLocation, *arrayType);
+        }
+
+        adjustRedeclaredBuiltInType(identifier, arrayType);
+
+        TVariable *variable = nullptr;
+        if (declareVariable(identifierLocation, identifier, arrayType, &variable))
+        {
+            TIntermSymbol *symbol = new TIntermSymbol(variable);
+            symbol->setLine(identifierLocation);
+            declarationOut->appendDeclarator(symbol);
+        }
+    }
+}
+
+void TParseContext::parseInitDeclarator(const TPublicType &publicType,
+                                        const TSourceLoc &identifierLocation,
+                                        const ImmutableString &identifier,
+                                        const TSourceLoc &initLocation,
+                                        TIntermTyped *initializer,
+                                        TIntermDeclaration *declarationOut)
+{
+    // If the declaration starting this declarator list was empty (example: int,), some checks were
+    // not performed.
+    if (mDeferredNonEmptyDeclarationErrorCheck)
+    {
+        nonEmptyDeclarationErrorCheck(publicType, identifierLocation);
+        mDeferredNonEmptyDeclarationErrorCheck = false;
+    }
+
+    checkDeclaratorLocationIsNotSpecified(identifierLocation, publicType);
+
+    TIntermBinary *initNode = nullptr;
+    TType *type             = new TType(publicType);
+    if (executeInitializer(identifierLocation, identifier, type, initializer, &initNode))
+    {
+        //
+        // build the intermediate representation
+        //
+        if (initNode)
+        {
+            declarationOut->appendDeclarator(initNode);
+        }
+    }
+}
+
+void TParseContext::parseArrayInitDeclarator(const TPublicType &elementType,
+                                             const TSourceLoc &identifierLocation,
+                                             const ImmutableString &identifier,
+                                             const TSourceLoc &indexLocation,
+                                             const TVector<unsigned int> &arraySizes,
+                                             const TSourceLoc &initLocation,
+                                             TIntermTyped *initializer,
+                                             TIntermDeclaration *declarationOut)
+{
+    // If the declaration starting this declarator list was empty (example: int,), some checks were
+    // not performed.
+    if (mDeferredNonEmptyDeclarationErrorCheck)
+    {
+        nonEmptyDeclarationErrorCheck(elementType, identifierLocation);
+        mDeferredNonEmptyDeclarationErrorCheck = false;
+    }
+
+    checkDeclaratorLocationIsNotSpecified(identifierLocation, elementType);
+
+    checkIsValidTypeAndQualifierForArray(indexLocation, elementType);
+
+    TType *arrayType = new TType(elementType);
+    arrayType->makeArrays(arraySizes);
+
+    // initNode will correspond to the whole of "b[n] = initializer".
+    TIntermBinary *initNode = nullptr;
+    if (executeInitializer(identifierLocation, identifier, arrayType, initializer, &initNode))
+    {
+        if (initNode)
+        {
+            declarationOut->appendDeclarator(initNode);
+        }
+    }
+}
+
+TIntermNode *TParseContext::addEmptyStatement(const TSourceLoc &location)
+{
+    // It's simpler to parse an empty statement as a constant expression rather than having a
+    // different type of node just for empty statements, that will be pruned from the AST anyway.
+    TIntermNode *node = CreateZeroNode(TType(EbtInt, EbpMedium));
+    node->setLine(location);
+    return node;
+}
+
+void TParseContext::setAtomicCounterBindingDefaultOffset(const TPublicType &publicType,
+                                                         const TSourceLoc &location)
+{
+    const TLayoutQualifier &layoutQualifier = publicType.layoutQualifier;
+    checkAtomicCounterBindingIsValid(location, layoutQualifier.binding);
+    if (layoutQualifier.binding == -1 || layoutQualifier.offset == -1)
+    {
+        error(location, "Requires both binding and offset", "layout");
+        return;
+    }
+    mAtomicCounterBindingStates[layoutQualifier.binding].setDefaultOffset(layoutQualifier.offset);
+}
+
+void TParseContext::parseDefaultPrecisionQualifier(const TPrecision precision,
+                                                   const TPublicType &type,
+                                                   const TSourceLoc &loc)
+{
+    if ((precision == EbpHigh) && (getShaderType() == GL_FRAGMENT_SHADER) &&
+        !getFragmentPrecisionHigh())
+    {
+        error(loc, "precision is not supported in fragment shader", "highp");
+    }
+
+    if (!CanSetDefaultPrecisionOnType(type))
+    {
+        error(loc, "illegal type argument for default precision qualifier",
+              getBasicString(type.getBasicType()));
+        return;
+    }
+    symbolTable.setDefaultPrecision(type.getBasicType(), precision);
+}
+
+bool TParseContext::checkPrimitiveTypeMatchesTypeQualifier(const TTypeQualifier &typeQualifier)
+{
+    switch (typeQualifier.layoutQualifier.primitiveType)
+    {
+        case EptLines:
+        case EptLinesAdjacency:
+        case EptTriangles:
+        case EptTrianglesAdjacency:
+            return typeQualifier.qualifier == EvqGeometryIn;
+
+        case EptLineStrip:
+        case EptTriangleStrip:
+            return typeQualifier.qualifier == EvqGeometryOut;
+
+        case EptPoints:
+            return true;
+
+        default:
+            UNREACHABLE();
+            return false;
+    }
+}
+
+void TParseContext::setGeometryShaderInputArraySize(unsigned int inputArraySize,
+                                                    const TSourceLoc &line)
+{
+    if (!symbolTable.setGlInArraySize(inputArraySize))
+    {
+        error(line,
+              "Array size or input primitive declaration doesn't match the size of earlier sized "
+              "array inputs.",
+              "layout");
+    }
+    mGeometryInputArraySize = inputArraySize;
+}
+
+bool TParseContext::parseGeometryShaderInputLayoutQualifier(const TTypeQualifier &typeQualifier)
+{
+    ASSERT(typeQualifier.qualifier == EvqGeometryIn);
+
+    const TLayoutQualifier &layoutQualifier = typeQualifier.layoutQualifier;
+
+    if (layoutQualifier.maxVertices != -1)
+    {
+        error(typeQualifier.line,
+              "max_vertices can only be declared in 'out' layout in a geometry shader", "layout");
+        return false;
+    }
+
+    // Set mGeometryInputPrimitiveType if exists
+    if (layoutQualifier.primitiveType != EptUndefined)
+    {
+        if (!checkPrimitiveTypeMatchesTypeQualifier(typeQualifier))
+        {
+            error(typeQualifier.line, "invalid primitive type for 'in' layout", "layout");
+            return false;
+        }
+
+        if (mGeometryShaderInputPrimitiveType == EptUndefined)
+        {
+            mGeometryShaderInputPrimitiveType = layoutQualifier.primitiveType;
+            setGeometryShaderInputArraySize(
+                GetGeometryShaderInputArraySize(mGeometryShaderInputPrimitiveType),
+                typeQualifier.line);
+        }
+        else if (mGeometryShaderInputPrimitiveType != layoutQualifier.primitiveType)
+        {
+            error(typeQualifier.line, "primitive doesn't match earlier input primitive declaration",
+                  "layout");
+            return false;
+        }
+
+        // Size any implicitly sized arrays that have already been declared.
+        for (TType *type : mDeferredArrayTypesToSize)
+        {
+            type->sizeOutermostUnsizedArray(
+                symbolTable.getGlInVariableWithArraySize()->getType().getOutermostArraySize());
+        }
+        mDeferredArrayTypesToSize.clear();
+    }
+
+    // Set mGeometryInvocations if exists
+    if (layoutQualifier.invocations > 0)
+    {
+        if (mGeometryShaderInvocations == 0)
+        {
+            mGeometryShaderInvocations = layoutQualifier.invocations;
+        }
+        else if (mGeometryShaderInvocations != layoutQualifier.invocations)
+        {
+            error(typeQualifier.line, "invocations contradicts to the earlier declaration",
+                  "layout");
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool TParseContext::parseGeometryShaderOutputLayoutQualifier(const TTypeQualifier &typeQualifier)
+{
+    ASSERT(typeQualifier.qualifier == EvqGeometryOut);
+
+    const TLayoutQualifier &layoutQualifier = typeQualifier.layoutQualifier;
+
+    if (layoutQualifier.invocations > 0)
+    {
+        error(typeQualifier.line,
+              "invocations can only be declared in 'in' layout in a geometry shader", "layout");
+        return false;
+    }
+
+    // Set mGeometryOutputPrimitiveType if exists
+    if (layoutQualifier.primitiveType != EptUndefined)
+    {
+        if (!checkPrimitiveTypeMatchesTypeQualifier(typeQualifier))
+        {
+            error(typeQualifier.line, "invalid primitive type for 'out' layout", "layout");
+            return false;
+        }
+
+        if (mGeometryShaderOutputPrimitiveType == EptUndefined)
+        {
+            mGeometryShaderOutputPrimitiveType = layoutQualifier.primitiveType;
+        }
+        else if (mGeometryShaderOutputPrimitiveType != layoutQualifier.primitiveType)
+        {
+            error(typeQualifier.line,
+                  "primitive doesn't match earlier output primitive declaration", "layout");
+            return false;
+        }
+    }
+
+    // Set mGeometryMaxVertices if exists
+    if (layoutQualifier.maxVertices > -1)
+    {
+        if (mGeometryShaderMaxVertices == -1)
+        {
+            mGeometryShaderMaxVertices = layoutQualifier.maxVertices;
+        }
+        else if (mGeometryShaderMaxVertices != layoutQualifier.maxVertices)
+        {
+            error(typeQualifier.line, "max_vertices contradicts to the earlier declaration",
+                  "layout");
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool TParseContext::parseTessControlShaderOutputLayoutQualifier(const TTypeQualifier &typeQualifier)
+{
+    ASSERT(typeQualifier.qualifier == EvqTessControlOut);
+
+    const TLayoutQualifier &layoutQualifier = typeQualifier.layoutQualifier;
+
+    if (layoutQualifier.vertices == 0)
+    {
+        error(typeQualifier.line, "No vertices specified", "layout");
+        return false;
+    }
+
+    // Set mTessControlShaderOutputVertices if exists
+    if (mTessControlShaderOutputVertices == 0)
+    {
+        mTessControlShaderOutputVertices = layoutQualifier.vertices;
+
+        // Size any implicitly sized arrays that have already been declared.
+        for (TType *type : mDeferredArrayTypesToSize)
+        {
+            type->sizeOutermostUnsizedArray(mTessControlShaderOutputVertices);
+        }
+        mDeferredArrayTypesToSize.clear();
+    }
+    else
+    {
+        error(typeQualifier.line, "Duplicated vertices specified", "layout");
+    }
+    return true;
+}
+
+bool TParseContext::parseTessEvaluationShaderInputLayoutQualifier(
+    const TTypeQualifier &typeQualifier)
+{
+    ASSERT(typeQualifier.qualifier == EvqTessEvaluationIn);
+
+    const TLayoutQualifier &layoutQualifier = typeQualifier.layoutQualifier;
+
+    // Set mTessEvaluationShaderInputPrimitiveType if exists
+    if (layoutQualifier.tesPrimitiveType != EtetUndefined)
+    {
+        if (mTessEvaluationShaderInputPrimitiveType == EtetUndefined)
+        {
+            mTessEvaluationShaderInputPrimitiveType = layoutQualifier.tesPrimitiveType;
+        }
+        else
+        {
+            error(typeQualifier.line, "Duplicated primitive type declaration", "layout");
+        }
+    }
+    // Set mTessEvaluationShaderVertexSpacingType if exists
+    if (layoutQualifier.tesVertexSpacingType != EtetUndefined)
+    {
+        if (mTessEvaluationShaderInputVertexSpacingType == EtetUndefined)
+        {
+            mTessEvaluationShaderInputVertexSpacingType = layoutQualifier.tesVertexSpacingType;
+        }
+        else
+        {
+            error(typeQualifier.line, "Duplicated vertex spacing declaration", "layout");
+        }
+    }
+    // Set mTessEvaluationShaderInputOrderingType if exists
+    if (layoutQualifier.tesOrderingType != EtetUndefined)
+    {
+        if (mTessEvaluationShaderInputOrderingType == EtetUndefined)
+        {
+            mTessEvaluationShaderInputOrderingType = layoutQualifier.tesOrderingType;
+        }
+        else
+        {
+            error(typeQualifier.line, "Duplicated ordering declaration", "layout");
+        }
+    }
+    // Set mTessEvaluationShaderInputPointType if exists
+    if (layoutQualifier.tesPointType != EtetUndefined)
+    {
+        if (mTessEvaluationShaderInputPointType == EtetUndefined)
+        {
+            mTessEvaluationShaderInputPointType = layoutQualifier.tesPointType;
+        }
+        else
+        {
+            error(typeQualifier.line, "Duplicated point type declaration", "layout");
+        }
+    }
+
+    return true;
+}
+
+void TParseContext::parseGlobalLayoutQualifier(const TTypeQualifierBuilder &typeQualifierBuilder)
+{
+    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);
+    const TLayoutQualifier layoutQualifier = typeQualifier.layoutQualifier;
+
+    checkInvariantVariableQualifier(typeQualifier.invariant, typeQualifier.qualifier,
+                                    typeQualifier.line);
+
+    // It should never be the case, but some strange parser errors can send us here.
+    if (layoutQualifier.isEmpty())
+    {
+        error(typeQualifier.line, "Error during layout qualifier parsing.", "?");
+        return;
+    }
+
+    if (!layoutQualifier.isCombinationValid())
+    {
+        error(typeQualifier.line, "invalid layout qualifier combination", "layout");
+        return;
+    }
+
+    checkIndexIsNotSpecified(typeQualifier.line, layoutQualifier.index);
+
+    checkBindingIsNotSpecified(typeQualifier.line, layoutQualifier.binding);
+
+    checkMemoryQualifierIsNotSpecified(typeQualifier.memoryQualifier, typeQualifier.line);
+
+    checkInternalFormatIsNotSpecified(typeQualifier.line, layoutQualifier.imageInternalFormat);
+
+    checkYuvIsNotSpecified(typeQualifier.line, layoutQualifier.yuv);
+
+    checkOffsetIsNotSpecified(typeQualifier.line, layoutQualifier.offset);
+
+    checkStd430IsForShaderStorageBlock(typeQualifier.line, layoutQualifier.blockStorage,
+                                       typeQualifier.qualifier);
+
+    checkAdvancedBlendEquationsNotSpecified(
+        typeQualifier.line, layoutQualifier.advancedBlendEquations, typeQualifier.qualifier);
+
+    if (typeQualifier.qualifier != EvqFragmentIn)
+    {
+        checkEarlyFragmentTestsIsNotSpecified(typeQualifier.line,
+                                              layoutQualifier.earlyFragmentTests);
+    }
+
+    if (typeQualifier.qualifier == EvqComputeIn)
+    {
+        if (mComputeShaderLocalSizeDeclared &&
+            !layoutQualifier.isLocalSizeEqual(mComputeShaderLocalSize))
+        {
+            error(typeQualifier.line, "Work group size does not match the previous declaration",
+                  "layout");
+            return;
+        }
+
+        if (mShaderVersion < 310)
+        {
+            error(typeQualifier.line, "in type qualifier supported in GLSL ES 3.10 only", "layout");
+            return;
+        }
+
+        if (!layoutQualifier.localSize.isAnyValueSet())
+        {
+            error(typeQualifier.line, "No local work group size specified", "layout");
+            return;
+        }
+
+        const TVariable *maxComputeWorkGroupSize = static_cast<const TVariable *>(
+            symbolTable.findBuiltIn(ImmutableString("gl_MaxComputeWorkGroupSize"), mShaderVersion));
+
+        const TConstantUnion *maxComputeWorkGroupSizeData =
+            maxComputeWorkGroupSize->getConstPointer();
+
+        for (size_t i = 0u; i < layoutQualifier.localSize.size(); ++i)
+        {
+            if (layoutQualifier.localSize[i] != -1)
+            {
+                mComputeShaderLocalSize[i]             = layoutQualifier.localSize[i];
+                const int maxComputeWorkGroupSizeValue = maxComputeWorkGroupSizeData[i].getIConst();
+                if (mComputeShaderLocalSize[i] < 1 ||
+                    mComputeShaderLocalSize[i] > maxComputeWorkGroupSizeValue)
+                {
+                    std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
+                    reasonStream << "invalid value: Value must be at least 1 and no greater than "
+                                 << maxComputeWorkGroupSizeValue;
+                    const std::string &reason = reasonStream.str();
+
+                    error(typeQualifier.line, reason.c_str(), getWorkGroupSizeString(i));
+                    return;
+                }
+            }
+        }
+
+        mComputeShaderLocalSizeDeclared = true;
+    }
+    else if (typeQualifier.qualifier == EvqGeometryIn)
+    {
+        if (mShaderVersion < 310)
+        {
+            error(typeQualifier.line, "in type qualifier supported in GLSL ES 3.10 only", "layout");
+            return;
+        }
+
+        if (!parseGeometryShaderInputLayoutQualifier(typeQualifier))
+        {
+            return;
+        }
+    }
+    else if (typeQualifier.qualifier == EvqGeometryOut)
+    {
+        if (mShaderVersion < 310)
+        {
+            error(typeQualifier.line, "out type qualifier supported in GLSL ES 3.10 only",
+                  "layout");
+            return;
+        }
+
+        if (!parseGeometryShaderOutputLayoutQualifier(typeQualifier))
+        {
+            return;
+        }
+    }
+    else if (anyMultiviewExtensionAvailable() && typeQualifier.qualifier == EvqVertexIn)
+    {
+        // This error is only specified in WebGL, but tightens unspecified behavior in the native
+        // specification.
+        if (mNumViews != -1 && layoutQualifier.numViews != mNumViews)
+        {
+            error(typeQualifier.line, "Number of views does not match the previous declaration",
+                  "layout");
+            return;
+        }
+
+        if (layoutQualifier.numViews == -1)
+        {
+            error(typeQualifier.line, "No num_views specified", "layout");
+            return;
+        }
+
+        if (layoutQualifier.numViews > mMaxNumViews)
+        {
+            error(typeQualifier.line, "num_views greater than the value of GL_MAX_VIEWS_OVR",
+                  "layout");
+            return;
+        }
+
+        mNumViews = layoutQualifier.numViews;
+    }
+    else if (typeQualifier.qualifier == EvqFragmentIn)
+    {
+        if (mShaderVersion < 310)
+        {
+            error(typeQualifier.line,
+                  "in type qualifier without variable declaration supported in GLSL ES 3.10 and "
+                  "after",
+                  "layout");
+            return;
+        }
+
+        if (!layoutQualifier.earlyFragmentTests)
+        {
+            error(typeQualifier.line,
+                  "only early_fragment_tests is allowed as layout qualifier when not declaring a "
+                  "variable",
+                  "layout");
+            return;
+        }
+
+        mEarlyFragmentTestsSpecified = true;
+    }
+    else if (typeQualifier.qualifier == EvqFragmentOut)
+    {
+        if (mShaderVersion < 320 && !isExtensionEnabled(TExtension::KHR_blend_equation_advanced))
+        {
+            error(typeQualifier.line,
+                  "out type qualifier without variable declaration is supported in GLSL ES 3.20,"
+                  " or if GL_KHR_blend_equation_advanced is enabled",
+                  "layout");
+            return;
+        }
+
+        if (!layoutQualifier.advancedBlendEquations.any())
+        {
+            error(typeQualifier.line,
+                  "only blend equations are allowed as layout qualifier when not declaring a "
+                  "variable",
+                  "layout");
+            return;
+        }
+
+        mAdvancedBlendEquations |= layoutQualifier.advancedBlendEquations;
+    }
+    else if (typeQualifier.qualifier == EvqTessControlOut)
+    {
+        if (mShaderVersion < 310)
+        {
+            error(typeQualifier.line, "out type qualifier supported in GLSL ES 3.10 and after",
+                  "layout");
+            return;
+        }
+
+        if (!parseTessControlShaderOutputLayoutQualifier(typeQualifier))
+        {
+            return;
+        }
+    }
+    else if (typeQualifier.qualifier == EvqTessEvaluationIn)
+    {
+        if (mShaderVersion < 310)
+        {
+            error(typeQualifier.line, "in type qualifier supported in GLSL ES 3.10 and after",
+                  "layout");
+            return;
+        }
+
+        if (!parseTessEvaluationShaderInputLayoutQualifier(typeQualifier))
+        {
+            return;
+        }
+    }
+    else
+    {
+        if (!checkWorkGroupSizeIsNotSpecified(typeQualifier.line, layoutQualifier))
+        {
+            return;
+        }
+
+        if (typeQualifier.qualifier != EvqUniform && typeQualifier.qualifier != EvqBuffer)
+        {
+            error(typeQualifier.line, "invalid qualifier: global layout can only be set for blocks",
+                  getQualifierString(typeQualifier.qualifier));
+            return;
+        }
+
+        if (mShaderVersion < 300)
+        {
+            error(typeQualifier.line, "layout qualifiers supported in GLSL ES 3.00 and after",
+                  "layout");
+            return;
+        }
+
+        checkLocationIsNotSpecified(typeQualifier.line, layoutQualifier);
+
+        if (layoutQualifier.matrixPacking != EmpUnspecified)
+        {
+            if (typeQualifier.qualifier == EvqUniform)
+            {
+                mDefaultUniformMatrixPacking = layoutQualifier.matrixPacking;
+            }
+            else if (typeQualifier.qualifier == EvqBuffer)
+            {
+                mDefaultBufferMatrixPacking = layoutQualifier.matrixPacking;
+            }
+        }
+
+        if (layoutQualifier.blockStorage != EbsUnspecified)
+        {
+            if (typeQualifier.qualifier == EvqUniform)
+            {
+                mDefaultUniformBlockStorage = layoutQualifier.blockStorage;
+            }
+            else if (typeQualifier.qualifier == EvqBuffer)
+            {
+                mDefaultBufferBlockStorage = layoutQualifier.blockStorage;
+            }
+        }
+    }
+}
+
+TIntermFunctionPrototype *TParseContext::createPrototypeNodeFromFunction(
+    const TFunction &function,
+    const TSourceLoc &location,
+    bool insertParametersToSymbolTable)
+{
+    checkIsNotReserved(location, function.name());
+
+    TIntermFunctionPrototype *prototype = new TIntermFunctionPrototype(&function);
+    prototype->setLine(location);
+
+    for (size_t i = 0; i < function.getParamCount(); i++)
+    {
+        const TVariable *param = function.getParam(i);
+
+        // If the parameter has no name, it's not an error, just don't add it to symbol table (could
+        // be used for unused args).
+        if (param->symbolType() != SymbolType::Empty)
+        {
+            if (insertParametersToSymbolTable)
+            {
+                if (!symbolTable.declare(const_cast<TVariable *>(param)))
+                {
+                    error(location, "redefinition", param->name());
+                }
+            }
+            // Unsized type of a named parameter should have already been checked and sanitized.
+            ASSERT(!param->getType().isUnsizedArray());
+        }
+        else
+        {
+            if (param->getType().isUnsizedArray())
+            {
+                error(location, "function parameter array must be sized at compile time", "[]");
+                // We don't need to size the arrays since the parameter is unnamed and hence
+                // inaccessible.
+            }
+        }
+    }
+    return prototype;
+}
+
+TIntermFunctionPrototype *TParseContext::addFunctionPrototypeDeclaration(
+    const TFunction &parsedFunction,
+    const TSourceLoc &location)
+{
+    // Note: function found from the symbol table could be the same as parsedFunction if this is the
+    // first declaration. Either way the instance in the symbol table is used to track whether the
+    // function is declared multiple times.
+    bool hadPrototypeDeclaration = false;
+    const TFunction *function    = symbolTable.markFunctionHasPrototypeDeclaration(
+           parsedFunction.getMangledName(), &hadPrototypeDeclaration);
+
+    if (hadPrototypeDeclaration && mShaderVersion == 100)
+    {
+        // ESSL 1.00.17 section 4.2.7.
+        // Doesn't apply to ESSL 3.00.4: see section 4.2.3.
+        error(location, "duplicate function prototype declarations are not allowed", "function");
+    }
+
+    TIntermFunctionPrototype *prototype =
+        createPrototypeNodeFromFunction(*function, location, false);
+
+    symbolTable.pop();
+
+    if (!symbolTable.atGlobalLevel())
+    {
+        // ESSL 3.00.4 section 4.2.4.
+        error(location, "local function prototype declarations are not allowed", "function");
+    }
+
+    return prototype;
+}
+
+TIntermFunctionDefinition *TParseContext::addFunctionDefinition(
+    TIntermFunctionPrototype *functionPrototype,
+    TIntermBlock *functionBody,
+    const TSourceLoc &location)
+{
+    // Undo push at end of parseFunctionDefinitionHeader() below for ESSL1.00 case
+    if (mFunctionBodyNewScope)
+    {
+        mFunctionBodyNewScope = false;
+        symbolTable.pop();
+    }
+
+    // Check that non-void functions have at least one return statement.
+    if (mCurrentFunctionType->getBasicType() != EbtVoid && !mFunctionReturnsValue)
+    {
+        error(location,
+              "function does not return a value:", functionPrototype->getFunction()->name());
+    }
+
+    if (functionBody == nullptr)
+    {
+        functionBody = new TIntermBlock();
+        functionBody->setLine(location);
+    }
+    TIntermFunctionDefinition *functionNode =
+        new TIntermFunctionDefinition(functionPrototype, functionBody);
+    functionNode->setLine(location);
+
+    symbolTable.pop();
+    return functionNode;
+}
+
+void TParseContext::parseFunctionDefinitionHeader(const TSourceLoc &location,
+                                                  const TFunction *function,
+                                                  TIntermFunctionPrototype **prototypeOut)
+{
+    ASSERT(function);
+
+    bool wasDefined = false;
+    function        = symbolTable.setFunctionParameterNamesFromDefinition(function, &wasDefined);
+    if (wasDefined)
+    {
+        error(location, "function already has a body", function->name());
+    }
+
+    // Remember the return type for later checking for return statements.
+    mCurrentFunctionType  = &(function->getReturnType());
+    mFunctionReturnsValue = false;
+
+    *prototypeOut = createPrototypeNodeFromFunction(*function, location, true);
+    setLoopNestingLevel(0);
+
+    // ESSL 1.00 spec allows for variable in function body to redefine parameter
+    if (IsSpecWithFunctionBodyNewScope(mShaderSpec, mShaderVersion))
+    {
+        mFunctionBodyNewScope = true;
+        symbolTable.push();
+    }
+}
+
+TFunction *TParseContext::parseFunctionDeclarator(const TSourceLoc &location, TFunction *function)
+{
+    //
+    // We don't know at this point whether this is a function definition or a prototype.
+    // The definition production code will check for redefinitions.
+    // In the case of ESSL 1.00 the prototype production code will also check for redeclarations.
+    //
+
+    for (size_t i = 0u; i < function->getParamCount(); ++i)
+    {
+        const TVariable *param = function->getParam(i);
+        const TType &paramType = param->getType();
+
+        if (paramType.isStructSpecifier())
+        {
+            // ESSL 3.00.6 section 12.10.
+            error(location, "Function parameter type cannot be a structure definition",
+                  function->name());
+        }
+
+        checkPrecisionSpecified(location, paramType.getPrecision(), paramType.getBasicType());
+    }
+
+    if (getShaderVersion() >= 300)
+    {
+        if (symbolTable.isUnmangledBuiltInName(function->name(), getShaderVersion(),
+                                               extensionBehavior()))
+        {
+            // With ESSL 3.00 and above, names of built-in functions cannot be redeclared as
+            // functions. Therefore overloading or redefining builtin functions is an error.
+            error(location, "Name of a built-in function cannot be redeclared as function",
+                  function->name());
+        }
+    }
+    else
+    {
+        // ESSL 1.00.17 section 4.2.6: built-ins can be overloaded but not redefined. We assume that
+        // this applies to redeclarations as well.
+        const TSymbol *builtIn =
+            symbolTable.findBuiltIn(function->getMangledName(), getShaderVersion());
+        if (builtIn)
+        {
+            error(location, "built-in functions cannot be redefined", function->name());
+        }
+    }
+
+    // Return types and parameter qualifiers must match in all redeclarations, so those are checked
+    // here.
+    const TFunction *prevDec =
+        static_cast<const TFunction *>(symbolTable.findGlobal(function->getMangledName()));
+    if (prevDec)
+    {
+        if (prevDec->getReturnType() != function->getReturnType())
+        {
+            error(location, "function must have the same return type in all of its declarations",
+                  function->getReturnType().getBasicString());
+        }
+        for (size_t i = 0; i < prevDec->getParamCount(); ++i)
+        {
+            if (prevDec->getParam(i)->getType().getQualifier() !=
+                function->getParam(i)->getType().getQualifier())
+            {
+                error(location,
+                      "function must have the same parameter qualifiers in all of its declarations",
+                      function->getParam(i)->getType().getQualifierString());
+            }
+        }
+    }
+
+    // Check for previously declared variables using the same name.
+    const TSymbol *prevSym   = symbolTable.find(function->name(), getShaderVersion());
+    bool insertUnmangledName = true;
+    if (prevSym)
+    {
+        if (!prevSym->isFunction())
+        {
+            error(location, "redefinition of a function", function->name());
+        }
+        insertUnmangledName = false;
+    }
+    // Parsing is at the inner scope level of the function's arguments and body statement at this
+    // point, but declareUserDefinedFunction takes care of declaring the function at the global
+    // scope.
+    symbolTable.declareUserDefinedFunction(function, insertUnmangledName);
+
+    // Raise error message if main function takes any parameters or return anything other than void
+    if (function->isMain())
+    {
+        if (function->getParamCount() > 0)
+        {
+            error(location, "function cannot take any parameter(s)", "main");
+        }
+        if (function->getReturnType().getBasicType() != EbtVoid)
+        {
+            error(location, "main function cannot return a value",
+                  function->getReturnType().getBasicString());
+        }
+    }
+
+    mDeclaringMain = function->isMain();
+
+    //
+    // If this is a redeclaration, it could also be a definition, in which case, we want to use the
+    // variable names from this one, and not the one that's
+    // being redeclared.  So, pass back up this declaration, not the one in the symbol table.
+    //
+    return function;
+}
+
+TFunction *TParseContext::parseFunctionHeader(const TPublicType &type,
+                                              const ImmutableString &name,
+                                              const TSourceLoc &location)
+{
+    if (type.qualifier != EvqGlobal && type.qualifier != EvqTemporary)
+    {
+        error(location, "no qualifiers allowed for function return",
+              getQualifierString(type.qualifier));
+    }
+    if (!type.layoutQualifier.isEmpty())
+    {
+        error(location, "no qualifiers allowed for function return", "layout");
+    }
+    // make sure an opaque type is not involved as well...
+    std::string reason(getBasicString(type.getBasicType()));
+    reason += "s can't be function return values";
+    checkIsNotOpaqueType(location, type.typeSpecifierNonArray, reason.c_str());
+    if (mShaderVersion < 300)
+    {
+        // Array return values are forbidden, but there's also no valid syntax for declaring array
+        // return values in ESSL 1.00.
+        ASSERT(!type.isArray() || mDiagnostics->numErrors() > 0);
+
+        if (type.isStructureContainingArrays())
+        {
+            // ESSL 1.00.17 section 6.1 Function Definitions
+            TInfoSinkBase typeString;
+            typeString << TType(type);
+            error(location, "structures containing arrays can't be function return values",
+                  typeString.c_str());
+        }
+    }
+
+    // Add the function as a prototype after parsing it (we do not support recursion)
+    return new TFunction(&symbolTable, name, SymbolType::UserDefined, new TType(type), false);
+}
+
+TFunctionLookup *TParseContext::addNonConstructorFunc(const ImmutableString &name,
+                                                      const TSymbol *symbol)
+{
+    return TFunctionLookup::CreateFunctionCall(name, symbol);
+}
+
+TFunctionLookup *TParseContext::addConstructorFunc(const TPublicType &publicType)
+{
+    if (mShaderVersion < 300 && publicType.isArray())
+    {
+        error(publicType.getLine(), "array constructor supported in GLSL ES 3.00 and above only",
+              "[]");
+    }
+    if (publicType.isStructSpecifier())
+    {
+        error(publicType.getLine(), "constructor can't be a structure definition",
+              getBasicString(publicType.getBasicType()));
+    }
+
+    TType *type = new TType(publicType);
+    if (!type->canBeConstructed())
+    {
+        error(publicType.getLine(), "cannot construct this type",
+              getBasicString(publicType.getBasicType()));
+        type->setBasicType(EbtFloat);
+    }
+    return TFunctionLookup::CreateConstructor(type);
+}
+
+void TParseContext::checkIsNotUnsizedArray(const TSourceLoc &line,
+                                           const char *errorMessage,
+                                           const ImmutableString &token,
+                                           TType *arrayType)
+{
+    if (arrayType->isUnsizedArray())
+    {
+        error(line, errorMessage, token);
+        arrayType->sizeUnsizedArrays(TSpan<const unsigned int>());
+    }
+}
+
+TParameter TParseContext::parseParameterDeclarator(TType *type,
+                                                   const ImmutableString &name,
+                                                   const TSourceLoc &nameLoc)
+{
+    ASSERT(type);
+    checkIsNotUnsizedArray(nameLoc, "function parameter array must specify a size", name, type);
+    if (type->getBasicType() == EbtVoid)
+    {
+        error(nameLoc, "illegal use of type 'void'", name);
+    }
+    checkIsNotReserved(nameLoc, name);
+    TParameter param = {name.data(), type};
+    return param;
+}
+
+TParameter TParseContext::parseParameterDeclarator(const TPublicType &publicType,
+                                                   const ImmutableString &name,
+                                                   const TSourceLoc &nameLoc)
+{
+    TType *type = new TType(publicType);
+    return parseParameterDeclarator(type, name, nameLoc);
+}
+
+TParameter TParseContext::parseParameterArrayDeclarator(const ImmutableString &name,
+                                                        const TSourceLoc &nameLoc,
+                                                        const TVector<unsigned int> &arraySizes,
+                                                        const TSourceLoc &arrayLoc,
+                                                        TPublicType *elementType)
+{
+    checkArrayElementIsNotArray(arrayLoc, *elementType);
+    TType *arrayType = new TType(*elementType);
+    arrayType->makeArrays(arraySizes);
+    return parseParameterDeclarator(arrayType, name, nameLoc);
+}
+
+bool TParseContext::checkUnsizedArrayConstructorArgumentDimensionality(
+    const TIntermSequence &arguments,
+    TType type,
+    const TSourceLoc &line)
+{
+    if (arguments.empty())
+    {
+        error(line, "implicitly sized array constructor must have at least one argument", "[]");
+        return false;
+    }
+    for (TIntermNode *arg : arguments)
+    {
+        const TIntermTyped *element = arg->getAsTyped();
+        ASSERT(element);
+        size_t dimensionalityFromElement = element->getType().getNumArraySizes() + 1u;
+        if (dimensionalityFromElement > type.getNumArraySizes())
+        {
+            error(line, "constructing from a non-dereferenced array", "constructor");
+            return false;
+        }
+        else if (dimensionalityFromElement < type.getNumArraySizes())
+        {
+            if (dimensionalityFromElement == 1u)
+            {
+                error(line, "implicitly sized array of arrays constructor argument is not an array",
+                      "constructor");
+            }
+            else
+            {
+                error(line,
+                      "implicitly sized array of arrays constructor argument dimensionality is too "
+                      "low",
+                      "constructor");
+            }
+            return false;
+        }
+    }
+    return true;
+}
+
+// This function is used to test for the correctness of the parameters passed to various constructor
+// functions and also convert them to the right datatype if it is allowed and required.
+//
+// Returns a node to add to the tree regardless of if an error was generated or not.
+//
+TIntermTyped *TParseContext::addConstructor(TFunctionLookup *fnCall, const TSourceLoc &line)
+{
+    TType type                 = fnCall->constructorType();
+    TIntermSequence &arguments = fnCall->arguments();
+    if (type.isUnsizedArray())
+    {
+        if (!checkUnsizedArrayConstructorArgumentDimensionality(arguments, type, line))
+        {
+            type.sizeUnsizedArrays(TSpan<const unsigned int>());
+            return CreateZeroNode(type);
+        }
+        TIntermTyped *firstElement = arguments.at(0)->getAsTyped();
+        ASSERT(firstElement);
+        if (type.getOutermostArraySize() == 0u)
+        {
+            type.sizeOutermostUnsizedArray(static_cast<unsigned int>(arguments.size()));
+        }
+        for (size_t i = 0; i < firstElement->getType().getNumArraySizes(); ++i)
+        {
+            if (type.getArraySizes()[i] == 0u)
+            {
+                type.setArraySize(i, firstElement->getType().getArraySizes()[i]);
+            }
+        }
+        ASSERT(!type.isUnsizedArray());
+    }
+
+    if (!checkConstructorArguments(line, arguments, type))
+    {
+        return CreateZeroNode(type);
+    }
+
+    TIntermAggregate *constructorNode = TIntermAggregate::CreateConstructor(type, &arguments);
+    constructorNode->setLine(line);
+
+    return constructorNode->fold(mDiagnostics);
+}
+
+//
+// Interface/uniform blocks
+TIntermDeclaration *TParseContext::addInterfaceBlock(
+    const TTypeQualifierBuilder &typeQualifierBuilder,
+    const TSourceLoc &nameLine,
+    const ImmutableString &blockName,
+    TFieldList *fieldList,
+    const ImmutableString &instanceName,
+    const TSourceLoc &instanceLine,
+    const TVector<unsigned int> *arraySizes,
+    const TSourceLoc &arraySizesLine)
+{
+    const bool isGLPerVertex = blockName == "gl_PerVertex";
+    // gl_PerVertex is allowed to be redefined and therefore not reserved
+    if (!isGLPerVertex)
+    {
+        checkIsNotReserved(nameLine, blockName);
+    }
+
+    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);
+
+    const bool isUniformOrBuffer =
+        typeQualifier.qualifier == EvqUniform || typeQualifier.qualifier == EvqBuffer;
+    const bool isShaderIoBlock = IsShaderIoBlock(typeQualifier.qualifier);
+
+    if (mShaderVersion < 310 && typeQualifier.qualifier != EvqUniform)
+    {
+        error(typeQualifier.line,
+              "invalid qualifier: interface blocks must be uniform in version lower than GLSL ES "
+              "3.10",
+              getQualifierString(typeQualifier.qualifier));
+    }
+    else if (typeQualifier.qualifier == EvqPatchOut)
+    {
+        if ((!isExtensionEnabled(TExtension::EXT_tessellation_shader) && mShaderVersion < 320) ||
+            mShaderType != GL_TESS_CONTROL_SHADER)
+        {
+            error(typeQualifier.line,
+                  "invalid qualifier: 'patch out' requires a tessellation control shader",
+                  getQualifierString(typeQualifier.qualifier));
+        }
+    }
+    else if (typeQualifier.qualifier == EvqPatchIn)
+    {
+        if ((!isExtensionEnabled(TExtension::EXT_tessellation_shader) && mShaderVersion < 320) ||
+            mShaderType != GL_TESS_EVALUATION_SHADER)
+        {
+            error(typeQualifier.line,
+                  "invalid qualifier: 'patch in' requires a tessellation evaluation shader",
+                  getQualifierString(typeQualifier.qualifier));
+        }
+    }
+    else if (typeQualifier.qualifier != EvqUniform && typeQualifier.qualifier != EvqBuffer)
+    {
+        if (isShaderIoBlock)
+        {
+            if (!isExtensionEnabled(TExtension::OES_shader_io_blocks) &&
+                !isExtensionEnabled(TExtension::EXT_shader_io_blocks) &&
+                !isExtensionEnabled(TExtension::OES_geometry_shader) &&
+                !isExtensionEnabled(TExtension::EXT_geometry_shader) && mShaderVersion < 320)
+            {
+                error(typeQualifier.line,
+                      "invalid qualifier: shader IO blocks need shader io block extension",
+                      getQualifierString(typeQualifier.qualifier));
+            }
+
+            // Both inputs and outputs of tessellation control shaders must be arrays.
+            // For tessellation evaluation shaders, only inputs must necessarily be arrays.
+            const bool isTCS = mShaderType == GL_TESS_CONTROL_SHADER;
+            const bool isTESIn =
+                mShaderType == GL_TESS_EVALUATION_SHADER && IsShaderIn(typeQualifier.qualifier);
+            if (arraySizes == nullptr && (isTCS || isTESIn))
+            {
+                error(typeQualifier.line, "type must be an array", blockName);
+            }
+        }
+        else
+        {
+            error(typeQualifier.line,
+                  "invalid qualifier: interface blocks must be uniform or buffer",
+                  getQualifierString(typeQualifier.qualifier));
+        }
+    }
+
+    if (typeQualifier.invariant)
+    {
+        error(typeQualifier.line, "invalid qualifier on interface block", "invariant");
+    }
+
+    if (typeQualifier.qualifier != EvqBuffer)
+    {
+        checkMemoryQualifierIsNotSpecified(typeQualifier.memoryQualifier, typeQualifier.line);
+    }
+
+    // Verify array sizes
+    if (arraySizes)
+    {
+        if (isUniformOrBuffer)
+        {
+            if (arraySizes->size() == 0)
+            {
+                error(arraySizesLine, "unsized arrays are not allowed with interface blocks", "");
+            }
+            if (arraySizes->size() > 1)
+            {
+                error(arraySizesLine, "array of arrays are not allowed with interface blocks", "");
+            }
+        }
+        else if (isShaderIoBlock)
+        {
+            size_t arrayDimensions = arraySizes->size();
+
+            // Geometry shader inputs have a level arrayness that must be ignored.
+            if (mShaderType == GL_GEOMETRY_SHADER_EXT && IsVaryingIn(typeQualifier.qualifier))
+            {
+                ASSERT(arrayDimensions > 0);
+                --arrayDimensions;
+
+                // Validate that the array size of input matches the geometry layout
+                // declaration, if not automatic (specified as []).
+                const unsigned int geometryDim = arraySizes->back();
+                if (geometryDim > 0 && geometryDim != mGeometryInputArraySize)
+                {
+                    error(arraySizesLine,
+                          "geometry shader input block array size inconsistent "
+                          "with primitive",
+                          "");
+                }
+            }
+
+            if (arrayDimensions > 1)
+            {
+                error(arraySizesLine, "array of arrays are not allowed with I/O blocks", "");
+            }
+        }
+    }
+    else if (isShaderIoBlock && mShaderType == GL_GEOMETRY_SHADER_EXT &&
+             IsVaryingIn(typeQualifier.qualifier))
+    {
+        error(arraySizesLine, "geometry shader input blocks must be an array", "");
+    }
+
+    checkIndexIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier.index);
+
+    if (mShaderVersion < 310)
+    {
+        checkBindingIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier.binding);
+    }
+    else
+    {
+        unsigned int arraySize =
+            arraySizes == nullptr || arraySizes->empty() ? 0 : (*arraySizes)[0];
+        checkBlockBindingIsValid(typeQualifier.line, typeQualifier.qualifier,
+                                 typeQualifier.layoutQualifier.binding, arraySize);
+    }
+
+    checkYuvIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier.yuv);
+    checkEarlyFragmentTestsIsNotSpecified(typeQualifier.line,
+                                          typeQualifier.layoutQualifier.earlyFragmentTests);
+    checkNoncoherentIsNotSpecified(typeQualifier.line, typeQualifier.layoutQualifier.noncoherent);
+
+    TLayoutQualifier blockLayoutQualifier = typeQualifier.layoutQualifier;
+    if (!IsShaderIoBlock(typeQualifier.qualifier) && typeQualifier.qualifier != EvqPatchIn &&
+        typeQualifier.qualifier != EvqPatchOut)
+    {
+        checkLocationIsNotSpecified(typeQualifier.line, blockLayoutQualifier);
+    }
+    checkStd430IsForShaderStorageBlock(typeQualifier.line, blockLayoutQualifier.blockStorage,
+                                       typeQualifier.qualifier);
+
+    if (blockLayoutQualifier.matrixPacking == EmpUnspecified)
+    {
+        if (typeQualifier.qualifier == EvqUniform)
+        {
+            blockLayoutQualifier.matrixPacking = mDefaultUniformMatrixPacking;
+        }
+        else if (typeQualifier.qualifier == EvqBuffer)
+        {
+            blockLayoutQualifier.matrixPacking = mDefaultBufferMatrixPacking;
+        }
+    }
+
+    if (blockLayoutQualifier.blockStorage == EbsUnspecified)
+    {
+        if (typeQualifier.qualifier == EvqUniform)
+        {
+            blockLayoutQualifier.blockStorage = mDefaultUniformBlockStorage;
+        }
+        else if (typeQualifier.qualifier == EvqBuffer)
+        {
+            blockLayoutQualifier.blockStorage = mDefaultBufferBlockStorage;
+        }
+    }
+
+    checkWorkGroupSizeIsNotSpecified(nameLine, blockLayoutQualifier);
+
+    checkInternalFormatIsNotSpecified(nameLine, blockLayoutQualifier.imageInternalFormat);
+
+    // check for sampler types and apply layout qualifiers
+    for (size_t memberIndex = 0; memberIndex < fieldList->size(); ++memberIndex)
+    {
+        TField *field    = (*fieldList)[memberIndex];
+        TType *fieldType = field->type();
+        if (IsOpaqueType(fieldType->getBasicType()))
+        {
+            std::string reason("unsupported type - ");
+            reason += fieldType->getBasicString();
+            reason += " types are not allowed in interface blocks";
+            error(field->line(), reason.c_str(), fieldType->getBasicString());
+        }
+
+        const TQualifier qualifier = fieldType->getQualifier();
+        switch (qualifier)
+        {
+            case EvqGlobal:
+                break;
+            case EvqUniform:
+                if (typeQualifier.qualifier == EvqBuffer)
+                {
+                    error(field->line(), "invalid qualifier on shader storage block member",
+                          getQualifierString(qualifier));
+                }
+                break;
+            case EvqBuffer:
+                if (typeQualifier.qualifier == EvqUniform)
+                {
+                    error(field->line(), "invalid qualifier on uniform block member",
+                          getQualifierString(qualifier));
+                }
+                break;
+            // a member variable in io block may have different interpolation.
+            case EvqFlatIn:
+            case EvqFlatOut:
+            case EvqNoPerspectiveIn:
+            case EvqNoPerspectiveOut:
+            case EvqSmoothIn:
+            case EvqSmoothOut:
+            case EvqCentroidIn:
+            case EvqCentroidOut:
+                break;
+            // a member variable can have an incomplete qualifier because shader io block has either
+            // in or out.
+            case EvqSmooth:
+            case EvqFlat:
+            case EvqNoPerspective:
+            case EvqCentroid:
+            case EvqGeometryIn:
+            case EvqGeometryOut:
+                if (!IsShaderIoBlock(typeQualifier.qualifier) &&
+                    typeQualifier.qualifier != EvqPatchIn &&
+                    typeQualifier.qualifier != EvqPatchOut &&
+                    typeQualifier.qualifier != EvqGeometryIn &&
+                    typeQualifier.qualifier != EvqGeometryOut)
+                {
+                    error(field->line(), "invalid qualifier on interface block member",
+                          getQualifierString(qualifier));
+                }
+                break;
+            default:
+                error(field->line(), "invalid qualifier on interface block member",
+                      getQualifierString(qualifier));
+                break;
+        }
+
+        // On interface block members, invariant is only applicable to output I/O blocks.
+        const bool isOutputShaderIoBlock = isShaderIoBlock && IsShaderOut(typeQualifier.qualifier);
+        if (fieldType->isInvariant() && !isOutputShaderIoBlock)
+        {
+            error(field->line(), "invalid qualifier on interface block member", "invariant");
+        }
+
+        // check layout qualifiers
+        TLayoutQualifier fieldLayoutQualifier = fieldType->getLayoutQualifier();
+        checkIndexIsNotSpecified(field->line(), fieldLayoutQualifier.index);
+        checkBindingIsNotSpecified(field->line(), fieldLayoutQualifier.binding);
+
+        if (fieldLayoutQualifier.blockStorage != EbsUnspecified)
+        {
+            error(field->line(), "invalid layout qualifier: cannot be used here",
+                  getBlockStorageString(fieldLayoutQualifier.blockStorage));
+        }
+
+        if (fieldLayoutQualifier.matrixPacking == EmpUnspecified)
+        {
+            fieldLayoutQualifier.matrixPacking = blockLayoutQualifier.matrixPacking;
+        }
+        else if (!fieldType->isMatrix() && fieldType->getBasicType() != EbtStruct)
+        {
+            warning(field->line(),
+                    "extraneous layout qualifier: only has an effect on matrix types",
+                    getMatrixPackingString(fieldLayoutQualifier.matrixPacking));
+        }
+
+        fieldType->setLayoutQualifier(fieldLayoutQualifier);
+
+        if (mShaderVersion < 310 || memberIndex != fieldList->size() - 1u ||
+            typeQualifier.qualifier != EvqBuffer)
+        {
+            // ESSL 3.10 spec section 4.1.9 allows for runtime-sized arrays.
+            checkIsNotUnsizedArray(field->line(),
+                                   "array members of interface blocks must specify a size",
+                                   field->name(), field->type());
+        }
+
+        if (typeQualifier.qualifier == EvqBuffer)
+        {
+            // set memory qualifiers
+            // GLSL ES 3.10 session 4.9 [Memory Access Qualifiers]. When a block declaration is
+            // qualified with a memory qualifier, it is as if all of its members were declared with
+            // the same memory qualifier.
+            const TMemoryQualifier &blockMemoryQualifier = typeQualifier.memoryQualifier;
+            TMemoryQualifier fieldMemoryQualifier        = fieldType->getMemoryQualifier();
+            fieldMemoryQualifier.readonly |= blockMemoryQualifier.readonly;
+            fieldMemoryQualifier.writeonly |= blockMemoryQualifier.writeonly;
+            fieldMemoryQualifier.coherent |= blockMemoryQualifier.coherent;
+            fieldMemoryQualifier.restrictQualifier |= blockMemoryQualifier.restrictQualifier;
+            fieldMemoryQualifier.volatileQualifier |= blockMemoryQualifier.volatileQualifier;
+            // TODO(jiajia.qin@intel.com): Decide whether if readonly and writeonly buffer variable
+            // is legal. See bug https://github.com/KhronosGroup/OpenGL-API/issues/7
+            fieldType->setMemoryQualifier(fieldMemoryQualifier);
+        }
+    }
+
+    SymbolType instanceSymbolType = SymbolType::UserDefined;
+    if (isGLPerVertex)
+    {
+        instanceSymbolType = SymbolType::BuiltIn;
+    }
+    TInterfaceBlock *interfaceBlock = new TInterfaceBlock(&symbolTable, blockName, fieldList,
+                                                          blockLayoutQualifier, instanceSymbolType);
+    if (!symbolTable.declare(interfaceBlock) && isUniformOrBuffer)
+    {
+        error(nameLine, "redefinition of an interface block name", blockName);
+    }
+
+    TType *interfaceBlockType =
+        new TType(interfaceBlock, typeQualifier.qualifier, blockLayoutQualifier);
+    if (arraySizes)
+    {
+        interfaceBlockType->makeArrays(*arraySizes);
+
+        checkGeometryShaderInputAndSetArraySize(instanceLine, instanceName, interfaceBlockType);
+        checkTessellationShaderUnsizedArraysAndSetSize(instanceLine, instanceName,
+                                                       interfaceBlockType);
+    }
+
+    // The instance variable gets created to refer to the interface block type from the AST
+    // regardless of if there's an instance name. It's created as an empty symbol if there is no
+    // instance name.
+    TVariable *instanceVariable =
+        new TVariable(&symbolTable, instanceName, interfaceBlockType,
+                      instanceName.empty() ? SymbolType::Empty : SymbolType::UserDefined);
+
+    if (instanceVariable->symbolType() == SymbolType::Empty)
+    {
+        // define symbols for the members of the interface block
+        for (size_t memberIndex = 0; memberIndex < fieldList->size(); ++memberIndex)
+        {
+            TField *field    = (*fieldList)[memberIndex];
+            TType *fieldType = new TType(*field->type());
+
+            // set parent pointer of the field variable
+            fieldType->setInterfaceBlockField(interfaceBlock, memberIndex);
+
+            fieldType->setQualifier(typeQualifier.qualifier);
+
+            SymbolType symbolType = SymbolType::UserDefined;
+            if (field->name() == "gl_Position" || field->name() == "gl_PointSize" ||
+                field->name() == "gl_ClipDistance" || field->name() == "gl_CullDistance")
+            {
+                // These builtins can be redifined only when used within a redefiend gl_PerVertex
+                // block
+                if (interfaceBlock->name() != "gl_PerVertex")
+                {
+                    error(field->line(), "redefinition in an invalid interface block",
+                          field->name());
+                }
+                symbolType = SymbolType::BuiltIn;
+            }
+            TVariable *fieldVariable =
+                new TVariable(&symbolTable, field->name(), fieldType, symbolType);
+            if (!symbolTable.declare(fieldVariable))
+            {
+                error(field->line(), "redefinition of an interface block member name",
+                      field->name());
+            }
+        }
+    }
+    else
+    {
+        checkIsNotReserved(instanceLine, instanceName);
+
+        // add a symbol for this interface block
+        if (!symbolTable.declare(instanceVariable))
+        {
+            error(instanceLine, "redefinition of an interface block instance name", instanceName);
+        }
+    }
+
+    TIntermSymbol *blockSymbol = new TIntermSymbol(instanceVariable);
+    blockSymbol->setLine(typeQualifier.line);
+    TIntermDeclaration *declaration = new TIntermDeclaration();
+    declaration->appendDeclarator(blockSymbol);
+    declaration->setLine(nameLine);
+
+    exitStructDeclaration();
+    return declaration;
+}
+
+void TParseContext::enterStructDeclaration(const TSourceLoc &line,
+                                           const ImmutableString &identifier)
+{
+    ++mStructNestingLevel;
+
+    // Embedded structure definitions are not supported per GLSL ES spec.
+    // ESSL 1.00.17 section 10.9. ESSL 3.00.6 section 12.11.
+    if (mStructNestingLevel > 1)
+    {
+        error(line, "Embedded struct definitions are not allowed", "struct");
+    }
+}
+
+void TParseContext::exitStructDeclaration()
+{
+    --mStructNestingLevel;
+}
+
+void TParseContext::checkIsBelowStructNestingLimit(const TSourceLoc &line, const TField &field)
+{
+    if (!sh::IsWebGLBasedSpec(mShaderSpec))
+    {
+        return;
+    }
+
+    if (field.type()->getBasicType() != EbtStruct)
+    {
+        return;
+    }
+
+    // We're already inside a structure definition at this point, so add
+    // one to the field's struct nesting.
+    if (1 + field.type()->getDeepestStructNesting() > kWebGLMaxStructNesting)
+    {
+        std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
+        if (field.type()->getStruct()->symbolType() == SymbolType::Empty)
+        {
+            // This may happen in case there are nested struct definitions. While they are also
+            // invalid GLSL, they don't cause a syntax error.
+            reasonStream << "Struct nesting";
+        }
+        else
+        {
+            reasonStream << "Reference of struct type " << field.type()->getStruct()->name();
+        }
+        reasonStream << " exceeds maximum allowed nesting level of " << kWebGLMaxStructNesting;
+        std::string reason = reasonStream.str();
+        error(line, reason.c_str(), field.name());
+        return;
+    }
+}
+
+//
+// Parse an array index expression
+//
+TIntermTyped *TParseContext::addIndexExpression(TIntermTyped *baseExpression,
+                                                const TSourceLoc &location,
+                                                TIntermTyped *indexExpression)
+{
+    if (!baseExpression->isArray() && !baseExpression->isMatrix() && !baseExpression->isVector())
+    {
+        if (baseExpression->getAsSymbolNode())
+        {
+            error(location, " left of '[' is not of type array, matrix, or vector ",
+                  baseExpression->getAsSymbolNode()->getName());
+        }
+        else
+        {
+            error(location, " left of '[' is not of type array, matrix, or vector ", "expression");
+        }
+
+        return CreateZeroNode(TType(EbtFloat, EbpHigh, EvqConst));
+    }
+
+    if (baseExpression->getQualifier() == EvqPerVertexIn)
+    {
+        if (mGeometryShaderInputPrimitiveType == EptUndefined &&
+            mShaderType == GL_GEOMETRY_SHADER_EXT)
+        {
+            error(location, "missing input primitive declaration before indexing gl_in.", "[");
+            return CreateZeroNode(TType(EbtFloat, EbpHigh, EvqConst));
+        }
+    }
+
+    TIntermConstantUnion *indexConstantUnion = indexExpression->getAsConstantUnion();
+
+    // ES3.2 or ES3.1's EXT_gpu_shader5 allow dynamically uniform expressions to be used as indices
+    // of opaque types (samplers and atomic counters) as well as UBOs, but not SSBOs and images.
+    bool allowUniformIndices =
+        mShaderVersion >= 320 || isExtensionEnabled(TExtension::EXT_gpu_shader5);
+
+    // ANGLE should be able to fold any constant expressions resulting in an integer - but to be
+    // safe we don't treat "EvqConst" that's evaluated according to the spec as being sufficient
+    // for constness. Some interpretations of the spec have allowed constant expressions with side
+    // effects - like array length() method on a non-constant array.
+    if (indexExpression->getQualifier() != EvqConst || indexConstantUnion == nullptr)
+    {
+        if (baseExpression->isInterfaceBlock())
+        {
+            switch (baseExpression->getQualifier())
+            {
+                case EvqPerVertexIn:
+                    break;
+                case EvqUniform:
+                    if (!allowUniformIndices)
+                    {
+                        error(location,
+                              "array indexes for uniform block arrays must be constant integral "
+                              "expressions",
+                              "[");
+                    }
+                    break;
+                case EvqBuffer:
+                    error(location,
+                          "array indexes for shader storage block arrays must be constant integral "
+                          "expressions",
+                          "[");
+                    break;
+                default:
+                    // It's ok for shader I/O blocks to be dynamically indexed
+                    if (!IsShaderIoBlock(baseExpression->getQualifier()) &&
+                        baseExpression->getQualifier() != EvqPatchIn &&
+                        baseExpression->getQualifier() != EvqPatchOut)
+                    {
+                        // We can reach here only in error cases.
+                        ASSERT(mDiagnostics->numErrors() > 0);
+                    }
+                    break;
+            }
+        }
+        else if (baseExpression->getQualifier() == EvqFragmentOut)
+        {
+            error(location,
+                  "array indexes for fragment outputs must be constant integral expressions", "[");
+        }
+        else if (mShaderSpec == SH_WEBGL2_SPEC && baseExpression->getQualifier() == EvqFragData)
+        {
+            error(location, "array index for gl_FragData must be constant zero", "[");
+        }
+        else if (baseExpression->isArray())
+        {
+            TBasicType elementType = baseExpression->getType().getBasicType();
+
+            // Note: In Section 12.30 of the ESSL 3.00 spec on p143-144:
+            //
+            //   Indexing of arrays of samplers by constant-index-expressions is
+            //   supported in GLSL ES 1.00. A constant-index-expression is an
+            //   expression formed from constant-expressions and certain loop indices,
+            //   defined for a subset of loop constructs. Should this functionality be
+            //   included in GLSL ES 3.00?
+            //
+            //   RESOLUTION: No. Arrays of samplers may only be indexed by constant-
+            //   integral-expressions.
+            if (IsSampler(elementType) && !allowUniformIndices && mShaderVersion > 100)
+            {
+                error(location, "array index for samplers must be constant integral expressions",
+                      "[");
+            }
+            else if (IsImage(elementType))
+            {
+                error(location,
+                      "array indexes for image arrays must be constant integral expressions", "[");
+            }
+        }
+    }
+
+    if (indexConstantUnion)
+    {
+        // If an out-of-range index is not qualified as constant, the behavior in the spec is
+        // undefined. This applies even if ANGLE has been able to constant fold it (ANGLE may
+        // constant fold expressions that are not constant expressions). The most compatible way to
+        // handle this case is to report a warning instead of an error and force the index to be in
+        // the correct range.
+        bool outOfRangeIndexIsError = indexExpression->getQualifier() == EvqConst;
+        int index                   = 0;
+        if (indexConstantUnion->getBasicType() == EbtInt)
+        {
+            index = indexConstantUnion->getIConst(0);
+        }
+        else if (indexConstantUnion->getBasicType() == EbtUInt)
+        {
+            index = static_cast<int>(indexConstantUnion->getUConst(0));
+        }
+
+        int safeIndex = -1;
+
+        if (index < 0)
+        {
+            outOfRangeError(outOfRangeIndexIsError, location, "index expression is negative", "[]");
+            safeIndex = 0;
+        }
+
+        if (!baseExpression->getType().isUnsizedArray())
+        {
+            if (baseExpression->isArray())
+            {
+                if (baseExpression->getQualifier() == EvqFragData && index > 0)
+                {
+                    if (!isExtensionEnabled(TExtension::EXT_draw_buffers))
+                    {
+                        outOfRangeError(outOfRangeIndexIsError, location,
+                                        "array index for gl_FragData must be zero when "
+                                        "GL_EXT_draw_buffers is disabled",
+                                        "[]");
+                        safeIndex = 0;
+                    }
+                }
+            }
+            // Only do generic out-of-range check if similar error hasn't already been reported.
+            if (safeIndex < 0)
+            {
+                if (baseExpression->isArray())
+                {
+                    safeIndex = checkIndexLessThan(outOfRangeIndexIsError, location, index,
+                                                   baseExpression->getOutermostArraySize(),
+                                                   "array index out of range");
+                }
+                else if (baseExpression->isMatrix())
+                {
+                    safeIndex = checkIndexLessThan(outOfRangeIndexIsError, location, index,
+                                                   baseExpression->getType().getCols(),
+                                                   "matrix field selection out of range");
+                }
+                else
+                {
+                    ASSERT(baseExpression->isVector());
+                    safeIndex = checkIndexLessThan(outOfRangeIndexIsError, location, index,
+                                                   baseExpression->getType().getNominalSize(),
+                                                   "vector field selection out of range");
+                }
+            }
+
+            ASSERT(safeIndex >= 0);
+            // Data of constant unions can't be changed, because it may be shared with other
+            // constant unions or even builtins, like gl_MaxDrawBuffers. Instead use a new
+            // sanitized object.
+            if (safeIndex != index || indexConstantUnion->getBasicType() != EbtInt)
+            {
+                TConstantUnion *safeConstantUnion = new TConstantUnion();
+                safeConstantUnion->setIConst(safeIndex);
+                indexExpression =
+                    new TIntermConstantUnion(safeConstantUnion, TType(indexExpression->getType()));
+            }
+
+            TIntermBinary *node =
+                new TIntermBinary(EOpIndexDirect, baseExpression, indexExpression);
+            node->setLine(location);
+            return expressionOrFoldedResult(node);
+        }
+    }
+
+    markStaticReadIfSymbol(indexExpression);
+    TIntermBinary *node = new TIntermBinary(EOpIndexIndirect, baseExpression, indexExpression);
+    node->setLine(location);
+    // Indirect indexing can never be constant folded.
+    return node;
+}
+
+int TParseContext::checkIndexLessThan(bool outOfRangeIndexIsError,
+                                      const TSourceLoc &location,
+                                      int index,
+                                      int arraySize,
+                                      const char *reason)
+{
+    // Should not reach here with an unsized / runtime-sized array.
+    ASSERT(arraySize > 0);
+    // A negative index should already have been checked.
+    ASSERT(index >= 0);
+    if (index >= arraySize)
+    {
+        std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
+        reasonStream << reason << " '" << index << "'";
+        std::string token = reasonStream.str();
+        outOfRangeError(outOfRangeIndexIsError, location, reason, "[]");
+        return arraySize - 1;
+    }
+    return index;
+}
+
+TIntermTyped *TParseContext::addFieldSelectionExpression(TIntermTyped *baseExpression,
+                                                         const TSourceLoc &dotLocation,
+                                                         const ImmutableString &fieldString,
+                                                         const TSourceLoc &fieldLocation)
+{
+    if (baseExpression->isArray())
+    {
+        error(fieldLocation, "cannot apply dot operator to an array", ".");
+        return baseExpression;
+    }
+
+    if (baseExpression->isVector())
+    {
+        TVector<int> fieldOffsets;
+        if (!parseVectorFields(fieldLocation, fieldString, baseExpression->getNominalSize(),
+                               &fieldOffsets))
+        {
+            fieldOffsets.resize(1);
+            fieldOffsets[0] = 0;
+        }
+        TIntermSwizzle *node = new TIntermSwizzle(baseExpression, fieldOffsets);
+        node->setLine(dotLocation);
+
+        return node->fold(mDiagnostics);
+    }
+    else if (baseExpression->getBasicType() == EbtStruct)
+    {
+        const TFieldList &fields = baseExpression->getType().getStruct()->fields();
+        if (fields.empty())
+        {
+            error(dotLocation, "structure has no fields", "Internal Error");
+            return baseExpression;
+        }
+        else
+        {
+            bool fieldFound = false;
+            unsigned int i;
+            for (i = 0; i < fields.size(); ++i)
+            {
+                if (fields[i]->name() == fieldString)
+                {
+                    fieldFound = true;
+                    break;
+                }
+            }
+            if (fieldFound)
+            {
+                TIntermTyped *index = CreateIndexNode(i);
+                index->setLine(fieldLocation);
+                TIntermBinary *node =
+                    new TIntermBinary(EOpIndexDirectStruct, baseExpression, index);
+                node->setLine(dotLocation);
+                return expressionOrFoldedResult(node);
+            }
+            else
+            {
+                error(dotLocation, " no such field in structure", fieldString);
+                return baseExpression;
+            }
+        }
+    }
+    else if (baseExpression->isInterfaceBlock())
+    {
+        const TFieldList &fields = baseExpression->getType().getInterfaceBlock()->fields();
+        if (fields.empty())
+        {
+            error(dotLocation, "interface block has no fields", "Internal Error");
+            return baseExpression;
+        }
+        else
+        {
+            bool fieldFound = false;
+            unsigned int i;
+            for (i = 0; i < fields.size(); ++i)
+            {
+                if (fields[i]->name() == fieldString)
+                {
+                    fieldFound = true;
+                    break;
+                }
+            }
+            if (fieldFound)
+            {
+                TIntermTyped *index = CreateIndexNode(i);
+                index->setLine(fieldLocation);
+                TIntermBinary *node =
+                    new TIntermBinary(EOpIndexDirectInterfaceBlock, baseExpression, index);
+                node->setLine(dotLocation);
+                // Indexing interface blocks can never be constant folded.
+                return node;
+            }
+            else
+            {
+                error(dotLocation, " no such field in interface block", fieldString);
+                return baseExpression;
+            }
+        }
+    }
+    else
+    {
+        if (mShaderVersion < 300)
+        {
+            error(dotLocation, " field selection requires structure or vector on left hand side",
+                  fieldString);
+        }
+        else
+        {
+            error(dotLocation,
+                  " field selection requires structure, vector, or interface block on left hand "
+                  "side",
+                  fieldString);
+        }
+        return baseExpression;
+    }
+}
+
+TLayoutQualifier TParseContext::parseLayoutQualifier(const ImmutableString &qualifierType,
+                                                     const TSourceLoc &qualifierTypeLine)
+{
+    TLayoutQualifier qualifier = TLayoutQualifier::Create();
+
+    if (qualifierType == "shared")
+    {
+        if (sh::IsWebGLBasedSpec(mShaderSpec))
+        {
+            error(qualifierTypeLine, "Only std140 layout is allowed in WebGL", "shared");
+        }
+        qualifier.blockStorage = EbsShared;
+    }
+    else if (qualifierType == "packed")
+    {
+        if (sh::IsWebGLBasedSpec(mShaderSpec))
+        {
+            error(qualifierTypeLine, "Only std140 layout is allowed in WebGL", "packed");
+        }
+        qualifier.blockStorage = EbsPacked;
+    }
+    else if (qualifierType == "std430")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.blockStorage = EbsStd430;
+    }
+    else if (qualifierType == "std140")
+    {
+        qualifier.blockStorage = EbsStd140;
+    }
+    else if (qualifierType == "row_major")
+    {
+        qualifier.matrixPacking = EmpRowMajor;
+    }
+    else if (qualifierType == "column_major")
+    {
+        qualifier.matrixPacking = EmpColumnMajor;
+    }
+    else if (qualifierType == "location")
+    {
+        error(qualifierTypeLine, "invalid layout qualifier: location requires an argument",
+              qualifierType);
+    }
+    else if (qualifierType == "yuv" && mShaderType == GL_FRAGMENT_SHADER)
+    {
+        if (checkCanUseExtension(qualifierTypeLine, TExtension::EXT_YUV_target))
+        {
+            qualifier.yuv = true;
+        }
+    }
+    else if (qualifierType == "early_fragment_tests")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.earlyFragmentTests = true;
+    }
+    else if (qualifierType == "rgba32f")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.imageInternalFormat = EiifRGBA32F;
+    }
+    else if (qualifierType == "rgba16f")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.imageInternalFormat = EiifRGBA16F;
+    }
+    else if (qualifierType == "r32f")
+    {
+        if (!isExtensionEnabled(TExtension::ANGLE_shader_pixel_local_storage))
+        {
+            checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        }
+        qualifier.imageInternalFormat = EiifR32F;
+    }
+    else if (qualifierType == "rgba8")
+    {
+        if (!isExtensionEnabled(TExtension::ANGLE_shader_pixel_local_storage))
+        {
+            checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        }
+        qualifier.imageInternalFormat = EiifRGBA8;
+    }
+    else if (qualifierType == "rgba8_snorm")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.imageInternalFormat = EiifRGBA8_SNORM;
+    }
+    else if (qualifierType == "rgba32i")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.imageInternalFormat = EiifRGBA32I;
+    }
+    else if (qualifierType == "rgba16i")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.imageInternalFormat = EiifRGBA16I;
+    }
+    else if (qualifierType == "rgba8i")
+    {
+        if (!isExtensionEnabled(TExtension::ANGLE_shader_pixel_local_storage))
+        {
+            checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        }
+        qualifier.imageInternalFormat = EiifRGBA8I;
+    }
+    else if (qualifierType == "r32i")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.imageInternalFormat = EiifR32I;
+    }
+    else if (qualifierType == "rgba32ui")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.imageInternalFormat = EiifRGBA32UI;
+    }
+    else if (qualifierType == "rgba16ui")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        qualifier.imageInternalFormat = EiifRGBA16UI;
+    }
+    else if (qualifierType == "rgba8ui")
+    {
+        if (!isExtensionEnabled(TExtension::ANGLE_shader_pixel_local_storage))
+        {
+            checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        }
+        qualifier.imageInternalFormat = EiifRGBA8UI;
+    }
+    else if (qualifierType == "r32ui")
+    {
+        if (!isExtensionEnabled(TExtension::ANGLE_shader_pixel_local_storage))
+        {
+            checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        }
+        qualifier.imageInternalFormat = EiifR32UI;
+    }
+    else if (mShaderType == GL_GEOMETRY_SHADER_EXT &&
+             (mShaderVersion >= 320 ||
+              (checkCanUseOneOfExtensions(
+                   qualifierTypeLine,
+                   std::array<TExtension, 2u>{
+                       {TExtension::EXT_geometry_shader, TExtension::OES_geometry_shader}}) &&
+               checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310))))
+    {
+        if (qualifierType == "points")
+        {
+            qualifier.primitiveType = EptPoints;
+        }
+        else if (qualifierType == "lines")
+        {
+            qualifier.primitiveType = EptLines;
+        }
+        else if (qualifierType == "lines_adjacency")
+        {
+            qualifier.primitiveType = EptLinesAdjacency;
+        }
+        else if (qualifierType == "triangles")
+        {
+            qualifier.primitiveType = EptTriangles;
+        }
+        else if (qualifierType == "triangles_adjacency")
+        {
+            qualifier.primitiveType = EptTrianglesAdjacency;
+        }
+        else if (qualifierType == "line_strip")
+        {
+            qualifier.primitiveType = EptLineStrip;
+        }
+        else if (qualifierType == "triangle_strip")
+        {
+            qualifier.primitiveType = EptTriangleStrip;
+        }
+        else
+        {
+            error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
+        }
+    }
+    else if (mShaderType == GL_TESS_EVALUATION_SHADER_EXT &&
+             (mShaderVersion >= 320 ||
+              (checkCanUseExtension(qualifierTypeLine, TExtension::EXT_tessellation_shader) &&
+               checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310))))
+    {
+        if (qualifierType == "triangles")
+        {
+            qualifier.tesPrimitiveType = EtetTriangles;
+        }
+        else if (qualifierType == "quads")
+        {
+            qualifier.tesPrimitiveType = EtetQuads;
+        }
+        else if (qualifierType == "isolines")
+        {
+            qualifier.tesPrimitiveType = EtetIsolines;
+        }
+        else if (qualifierType == "equal_spacing")
+        {
+            qualifier.tesVertexSpacingType = EtetEqualSpacing;
+        }
+        else if (qualifierType == "fractional_even_spacing")
+        {
+            qualifier.tesVertexSpacingType = EtetFractionalEvenSpacing;
+        }
+        else if (qualifierType == "fractional_odd_spacing")
+        {
+            qualifier.tesVertexSpacingType = EtetFractionalOddSpacing;
+        }
+        else if (qualifierType == "cw")
+        {
+            qualifier.tesOrderingType = EtetCw;
+        }
+        else if (qualifierType == "ccw")
+        {
+            qualifier.tesOrderingType = EtetCcw;
+        }
+        else if (qualifierType == "point_mode")
+        {
+            qualifier.tesPointType = EtetPointMode;
+        }
+        else
+        {
+            error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
+        }
+    }
+    else if (mShaderType == GL_FRAGMENT_SHADER)
+    {
+        if (qualifierType == "noncoherent")
+        {
+            if (checkCanUseOneOfExtensions(
+                    qualifierTypeLine,
+                    std::array<TExtension, 2u>{
+                        {TExtension::EXT_shader_framebuffer_fetch,
+                         TExtension::EXT_shader_framebuffer_fetch_non_coherent}}))
+            {
+                checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 100);
+                qualifier.noncoherent = true;
+            }
+        }
+        else if (qualifierType == "blend_support_multiply")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Multiply, &qualifier);
+        }
+        else if (qualifierType == "blend_support_screen")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Screen, &qualifier);
+        }
+        else if (qualifierType == "blend_support_overlay")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Overlay, &qualifier);
+        }
+        else if (qualifierType == "blend_support_darken")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Darken, &qualifier);
+        }
+        else if (qualifierType == "blend_support_lighten")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Lighten, &qualifier);
+        }
+        else if (qualifierType == "blend_support_colordodge")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Colordodge, &qualifier);
+        }
+        else if (qualifierType == "blend_support_colorburn")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Colorburn, &qualifier);
+        }
+        else if (qualifierType == "blend_support_hardlight")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Hardlight, &qualifier);
+        }
+        else if (qualifierType == "blend_support_softlight")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Softlight, &qualifier);
+        }
+        else if (qualifierType == "blend_support_difference")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Difference, &qualifier);
+        }
+        else if (qualifierType == "blend_support_exclusion")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::Exclusion, &qualifier);
+        }
+        else if (qualifierType == "blend_support_hsl_hue")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::HslHue, &qualifier);
+        }
+        else if (qualifierType == "blend_support_hsl_saturation")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::HslSaturation, &qualifier);
+        }
+        else if (qualifierType == "blend_support_hsl_color")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::HslColor, &qualifier);
+        }
+        else if (qualifierType == "blend_support_hsl_luminosity")
+        {
+            AddAdvancedBlendEquation(gl::BlendEquationType::HslLuminosity, &qualifier);
+        }
+        else if (qualifierType == "blend_support_all_equations")
+        {
+            qualifier.advancedBlendEquations.setAll();
+        }
+        else
+        {
+            error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
+        }
+
+        if (qualifier.advancedBlendEquations.any() && mShaderVersion < 320)
+        {
+            if (!checkCanUseExtension(qualifierTypeLine, TExtension::KHR_blend_equation_advanced))
+            {
+                qualifier.advancedBlendEquations.reset();
+            }
+        }
+    }
+    else
+    {
+        error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
+    }
+
+    return qualifier;
+}
+
+void TParseContext::parseLocalSize(const ImmutableString &qualifierType,
+                                   const TSourceLoc &qualifierTypeLine,
+                                   int intValue,
+                                   const TSourceLoc &intValueLine,
+                                   const std::string &intValueString,
+                                   size_t index,
+                                   sh::WorkGroupSize *localSize)
+{
+    checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+    if (intValue < 1)
+    {
+        std::stringstream reasonStream = sh::InitializeStream<std::stringstream>();
+        reasonStream << "out of range: " << getWorkGroupSizeString(index) << " must be positive";
+        std::string reason = reasonStream.str();
+        error(intValueLine, reason.c_str(), intValueString.c_str());
+    }
+    (*localSize)[index] = intValue;
+}
+
+void TParseContext::parseNumViews(int intValue,
+                                  const TSourceLoc &intValueLine,
+                                  const std::string &intValueString,
+                                  int *numViews)
+{
+    // This error is only specified in WebGL, but tightens unspecified behavior in the native
+    // specification.
+    if (intValue < 1)
+    {
+        error(intValueLine, "out of range: num_views must be positive", intValueString.c_str());
+    }
+    *numViews = intValue;
+}
+
+void TParseContext::parseInvocations(int intValue,
+                                     const TSourceLoc &intValueLine,
+                                     const std::string &intValueString,
+                                     int *numInvocations)
+{
+    // Although SPEC isn't clear whether invocations can be less than 1, we add this limit because
+    // it doesn't make sense to accept invocations <= 0.
+    if (intValue < 1 || intValue > mMaxGeometryShaderInvocations)
+    {
+        error(intValueLine,
+              "out of range: invocations must be in the range of [1, "
+              "MAX_GEOMETRY_SHADER_INVOCATIONS_OES]",
+              intValueString.c_str());
+    }
+    else
+    {
+        *numInvocations = intValue;
+    }
+}
+
+void TParseContext::parseMaxVertices(int intValue,
+                                     const TSourceLoc &intValueLine,
+                                     const std::string &intValueString,
+                                     int *maxVertices)
+{
+    // Although SPEC isn't clear whether max_vertices can be less than 0, we add this limit because
+    // it doesn't make sense to accept max_vertices < 0.
+    if (intValue < 0 || intValue > mMaxGeometryShaderMaxVertices)
+    {
+        error(
+            intValueLine,
+            "out of range: max_vertices must be in the range of [0, gl_MaxGeometryOutputVertices]",
+            intValueString.c_str());
+    }
+    else
+    {
+        *maxVertices = intValue;
+    }
+}
+
+void TParseContext::parseVertices(int intValue,
+                                  const TSourceLoc &intValueLine,
+                                  const std::string &intValueString,
+                                  int *vertices)
+{
+    if (intValue < 1 || intValue > mMaxPatchVertices)
+    {
+        error(intValueLine,
+              "out of range : vertices must be in the range of [1, gl_MaxPatchVertices]",
+              intValueString.c_str());
+    }
+    else
+    {
+        *vertices = intValue;
+    }
+}
+
+void TParseContext::parseIndexLayoutQualifier(int intValue,
+                                              const TSourceLoc &intValueLine,
+                                              const std::string &intValueString,
+                                              int *index)
+{
+    // EXT_blend_func_extended specifies that most validation should happen at link time, but since
+    // we're validating output variable locations at compile time, it makes sense to validate that
+    // index is 0 or 1 also at compile time. Also since we use "-1" as a placeholder for unspecified
+    // index, we can't accept it here.
+    if (intValue < 0 || intValue > 1)
+    {
+        error(intValueLine, "out of range: index layout qualifier can only be 0 or 1",
+              intValueString.c_str());
+    }
+    else
+    {
+        *index = intValue;
+    }
+}
+
+TLayoutQualifier TParseContext::parseLayoutQualifier(const ImmutableString &qualifierType,
+                                                     const TSourceLoc &qualifierTypeLine,
+                                                     int intValue,
+                                                     const TSourceLoc &intValueLine)
+{
+    TLayoutQualifier qualifier = TLayoutQualifier::Create();
+
+    std::string intValueString = Str(intValue);
+
+    if (qualifierType == "location")
+    {
+        // must check that location is non-negative
+        if (intValue < 0)
+        {
+            error(intValueLine, "out of range: location must be non-negative",
+                  intValueString.c_str());
+        }
+        else
+        {
+            qualifier.location           = intValue;
+            qualifier.locationsSpecified = 1;
+        }
+    }
+    else if (qualifierType == "binding")
+    {
+        if (!isExtensionEnabled(TExtension::ANGLE_shader_pixel_local_storage))
+        {
+            checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        }
+        if (intValue < 0)
+        {
+            error(intValueLine, "out of range: binding must be non-negative",
+                  intValueString.c_str());
+        }
+        else
+        {
+            qualifier.binding = intValue;
+        }
+    }
+    else if (qualifierType == "offset")
+    {
+        checkLayoutQualifierSupported(qualifierTypeLine, qualifierType, 310);
+        if (intValue < 0)
+        {
+            error(intValueLine, "out of range: offset must be non-negative",
+                  intValueString.c_str());
+        }
+        else
+        {
+            qualifier.offset = intValue;
+        }
+    }
+    else if (qualifierType == "local_size_x")
+    {
+        parseLocalSize(qualifierType, qualifierTypeLine, intValue, intValueLine, intValueString, 0u,
+                       &qualifier.localSize);
+    }
+    else if (qualifierType == "local_size_y")
+    {
+        parseLocalSize(qualifierType, qualifierTypeLine, intValue, intValueLine, intValueString, 1u,
+                       &qualifier.localSize);
+    }
+    else if (qualifierType == "local_size_z")
+    {
+        parseLocalSize(qualifierType, qualifierTypeLine, intValue, intValueLine, intValueString, 2u,
+                       &qualifier.localSize);
+    }
+    else if (qualifierType == "num_views" && mShaderType == GL_VERTEX_SHADER)
+    {
+        if (checkCanUseOneOfExtensions(
+                qualifierTypeLine, std::array<TExtension, 2u>{
+                                       {TExtension::OVR_multiview, TExtension::OVR_multiview2}}))
+        {
+            parseNumViews(intValue, intValueLine, intValueString, &qualifier.numViews);
+        }
+    }
+    else if (qualifierType == "invocations" && mShaderType == GL_GEOMETRY_SHADER_EXT &&
+             (mShaderVersion >= 320 ||
+              checkCanUseOneOfExtensions(
+                  qualifierTypeLine,
+                  std::array<TExtension, 2u>{
+                      {TExtension::EXT_geometry_shader, TExtension::OES_geometry_shader}})))
+    {
+        parseInvocations(intValue, intValueLine, intValueString, &qualifier.invocations);
+    }
+    else if (qualifierType == "max_vertices" && mShaderType == GL_GEOMETRY_SHADER_EXT &&
+             (mShaderVersion >= 320 ||
+              checkCanUseOneOfExtensions(
+                  qualifierTypeLine,
+                  std::array<TExtension, 2u>{
+                      {TExtension::EXT_geometry_shader, TExtension::OES_geometry_shader}})))
+    {
+        parseMaxVertices(intValue, intValueLine, intValueString, &qualifier.maxVertices);
+    }
+    else if (qualifierType == "index" && mShaderType == GL_FRAGMENT_SHADER &&
+             checkCanUseExtension(qualifierTypeLine, TExtension::EXT_blend_func_extended))
+    {
+        parseIndexLayoutQualifier(intValue, intValueLine, intValueString, &qualifier.index);
+    }
+    else if (qualifierType == "vertices" && mShaderType == GL_TESS_CONTROL_SHADER_EXT &&
+             (mShaderVersion >= 320 ||
+              checkCanUseExtension(qualifierTypeLine, TExtension::EXT_tessellation_shader)))
+    {
+        parseVertices(intValue, intValueLine, intValueString, &qualifier.vertices);
+    }
+    else
+    {
+        error(qualifierTypeLine, "invalid layout qualifier", qualifierType);
+    }
+
+    return qualifier;
+}
+
+TTypeQualifierBuilder *TParseContext::createTypeQualifierBuilder(const TSourceLoc &loc)
+{
+    return new TTypeQualifierBuilder(
+        new TStorageQualifierWrapper(symbolTable.atGlobalLevel() ? EvqGlobal : EvqTemporary, loc),
+        mShaderVersion);
+}
+
+TStorageQualifierWrapper *TParseContext::parseGlobalStorageQualifier(TQualifier qualifier,
+                                                                     const TSourceLoc &loc)
+{
+    checkIsAtGlobalLevel(loc, getQualifierString(qualifier));
+    return new TStorageQualifierWrapper(qualifier, loc);
+}
+
+TStorageQualifierWrapper *TParseContext::parseVaryingQualifier(const TSourceLoc &loc)
+{
+    if (getShaderType() == GL_VERTEX_SHADER)
+    {
+        return parseGlobalStorageQualifier(EvqVaryingOut, loc);
+    }
+    return parseGlobalStorageQualifier(EvqVaryingIn, loc);
+}
+
+TStorageQualifierWrapper *TParseContext::parseInQualifier(const TSourceLoc &loc)
+{
+    if (declaringFunction())
+    {
+        return new TStorageQualifierWrapper(EvqParamIn, loc);
+    }
+
+    switch (getShaderType())
+    {
+        case GL_VERTEX_SHADER:
+        {
+            if (mShaderVersion < 300 && !anyMultiviewExtensionAvailable() &&
+                !IsDesktopGLSpec(mShaderSpec))
+            {
+                error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "in");
+            }
+            return new TStorageQualifierWrapper(EvqVertexIn, loc);
+        }
+        case GL_FRAGMENT_SHADER:
+        {
+            if (mShaderVersion < 300 && !IsDesktopGLSpec(mShaderSpec))
+            {
+                error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "in");
+            }
+            return new TStorageQualifierWrapper(EvqFragmentIn, loc);
+        }
+        case GL_COMPUTE_SHADER:
+        {
+            return new TStorageQualifierWrapper(EvqComputeIn, loc);
+        }
+        case GL_GEOMETRY_SHADER:
+        {
+            return new TStorageQualifierWrapper(EvqGeometryIn, loc);
+        }
+        case GL_TESS_CONTROL_SHADER:
+        {
+            return new TStorageQualifierWrapper(EvqTessControlIn, loc);
+        }
+        case GL_TESS_EVALUATION_SHADER:
+        {
+            return new TStorageQualifierWrapper(EvqTessEvaluationIn, loc);
+        }
+        default:
+        {
+            UNREACHABLE();
+            return new TStorageQualifierWrapper(EvqLast, loc);
+        }
+    }
+}
+
+TStorageQualifierWrapper *TParseContext::parseOutQualifier(const TSourceLoc &loc)
+{
+    if (declaringFunction())
+    {
+        return new TStorageQualifierWrapper(EvqParamOut, loc);
+    }
+    switch (getShaderType())
+    {
+        case GL_VERTEX_SHADER:
+        {
+            if (mShaderVersion < 300 && !IsDesktopGLSpec(mShaderSpec))
+            {
+                error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "out");
+            }
+            return new TStorageQualifierWrapper(EvqVertexOut, loc);
+        }
+        case GL_FRAGMENT_SHADER:
+        {
+            if (mShaderVersion < 300 && !IsDesktopGLSpec(mShaderSpec))
+            {
+                error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "out");
+            }
+            return new TStorageQualifierWrapper(EvqFragmentOut, loc);
+        }
+        case GL_COMPUTE_SHADER:
+        {
+            error(loc, "storage qualifier isn't supported in compute shaders", "out");
+            return new TStorageQualifierWrapper(EvqParamOut, loc);
+        }
+        case GL_GEOMETRY_SHADER_EXT:
+        {
+            return new TStorageQualifierWrapper(EvqGeometryOut, loc);
+        }
+        case GL_TESS_CONTROL_SHADER_EXT:
+        {
+            return new TStorageQualifierWrapper(EvqTessControlOut, loc);
+        }
+        case GL_TESS_EVALUATION_SHADER_EXT:
+        {
+            return new TStorageQualifierWrapper(EvqTessEvaluationOut, loc);
+        }
+        default:
+        {
+            UNREACHABLE();
+            return new TStorageQualifierWrapper(EvqLast, loc);
+        }
+    }
+}
+
+TStorageQualifierWrapper *TParseContext::parseInOutQualifier(const TSourceLoc &loc)
+{
+    if (!declaringFunction())
+    {
+        if (mShaderVersion < 300 && !IsDesktopGLSpec(mShaderSpec))
+        {
+            error(loc, "storage qualifier supported in GLSL ES 3.00 and above only", "inout");
+        }
+
+        if (getShaderType() != GL_FRAGMENT_SHADER)
+        {
+            error(loc, "storage qualifier isn't supported in non-fragment shaders", "inout");
+        }
+
+        if (isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch) ||
+            isExtensionEnabled(TExtension::EXT_shader_framebuffer_fetch_non_coherent))
+        {
+            return new TStorageQualifierWrapper(EvqFragmentInOut, loc);
+        }
+
+        error(loc,
+              "invalid qualifier: can be used with either function parameters or the variables for "
+              "fetching input attachment data",
+              "inout");
+    }
+    return new TStorageQualifierWrapper(EvqParamInOut, loc);
+}
+
+TLayoutQualifier TParseContext::joinLayoutQualifiers(TLayoutQualifier leftQualifier,
+                                                     TLayoutQualifier rightQualifier,
+                                                     const TSourceLoc &rightQualifierLocation)
+{
+    return sh::JoinLayoutQualifiers(leftQualifier, rightQualifier, rightQualifierLocation,
+                                    mDiagnostics);
+}
+
+TDeclarator *TParseContext::parseStructDeclarator(const ImmutableString &identifier,
+                                                  const TSourceLoc &loc)
+{
+    return new TDeclarator(identifier, loc);
+}
+
+TDeclarator *TParseContext::parseStructArrayDeclarator(const ImmutableString &identifier,
+                                                       const TSourceLoc &loc,
+                                                       const TVector<unsigned int> *arraySizes)
+{
+    return new TDeclarator(identifier, arraySizes, loc);
+}
+
+void TParseContext::checkDoesNotHaveDuplicateFieldName(const TFieldList::const_iterator begin,
+                                                       const TFieldList::const_iterator end,
+                                                       const ImmutableString &name,
+                                                       const TSourceLoc &location)
+{
+    for (auto fieldIter = begin; fieldIter != end; ++fieldIter)
+    {
+        if ((*fieldIter)->name() == name)
+        {
+            error(location, "duplicate field name in structure", name);
+        }
+    }
+}
+
+TFieldList *TParseContext::addStructFieldList(TFieldList *fields, const TSourceLoc &location)
+{
+    for (TFieldList::const_iterator fieldIter = fields->begin(); fieldIter != fields->end();
+         ++fieldIter)
+    {
+        checkDoesNotHaveDuplicateFieldName(fields->begin(), fieldIter, (*fieldIter)->name(),
+                                           location);
+    }
+    return fields;
+}
+
+TFieldList *TParseContext::combineStructFieldLists(TFieldList *processedFields,
+                                                   const TFieldList *newlyAddedFields,
+                                                   const TSourceLoc &location)
+{
+    for (TField *field : *newlyAddedFields)
+    {
+        checkDoesNotHaveDuplicateFieldName(processedFields->begin(), processedFields->end(),
+                                           field->name(), location);
+        processedFields->push_back(field);
+    }
+    return processedFields;
+}
+
+TFieldList *TParseContext::addStructDeclaratorListWithQualifiers(
+    const TTypeQualifierBuilder &typeQualifierBuilder,
+    TPublicType *typeSpecifier,
+    const TDeclaratorList *declaratorList)
+{
+    TTypeQualifier typeQualifier = typeQualifierBuilder.getVariableTypeQualifier(mDiagnostics);
+
+    typeSpecifier->qualifier       = typeQualifier.qualifier;
+    typeSpecifier->layoutQualifier = typeQualifier.layoutQualifier;
+    typeSpecifier->memoryQualifier = typeQualifier.memoryQualifier;
+    typeSpecifier->invariant       = typeQualifier.invariant;
+    typeSpecifier->precise         = typeQualifier.precise;
+    if (typeQualifier.precision != EbpUndefined)
+    {
+        typeSpecifier->precision = typeQualifier.precision;
+    }
+    return addStructDeclaratorList(*typeSpecifier, declaratorList);
+}
+
+TFieldList *TParseContext::addStructDeclaratorList(const TPublicType &typeSpecifier,
+                                                   const TDeclaratorList *declaratorList)
+{
+    checkPrecisionSpecified(typeSpecifier.getLine(), typeSpecifier.precision,
+                            typeSpecifier.getBasicType());
+
+    checkIsNonVoid(typeSpecifier.getLine(), (*declaratorList)[0]->name(),
+                   typeSpecifier.getBasicType());
+
+    checkWorkGroupSizeIsNotSpecified(typeSpecifier.getLine(), typeSpecifier.layoutQualifier);
+    checkEarlyFragmentTestsIsNotSpecified(typeSpecifier.getLine(),
+                                          typeSpecifier.layoutQualifier.earlyFragmentTests);
+    checkNoncoherentIsNotSpecified(typeSpecifier.getLine(),
+                                   typeSpecifier.layoutQualifier.noncoherent);
+
+    TFieldList *fieldList = new TFieldList();
+
+    for (const TDeclarator *declarator : *declaratorList)
+    {
+        TType *type = new TType(typeSpecifier);
+        if (declarator->isArray())
+        {
+            // Don't allow arrays of arrays in ESSL < 3.10.
+            checkArrayElementIsNotArray(typeSpecifier.getLine(), typeSpecifier);
+            type->makeArrays(*declarator->arraySizes());
+        }
+
+        SymbolType symbolType = SymbolType::UserDefined;
+        if (declarator->name() == "gl_Position" || declarator->name() == "gl_PointSize" ||
+            declarator->name() == "gl_ClipDistance" || declarator->name() == "gl_CullDistance")
+        {
+            symbolType = SymbolType::BuiltIn;
+        }
+        else
+        {
+            checkIsNotReserved(typeSpecifier.getLine(), declarator->name());
+        }
+        TField *field = new TField(type, declarator->name(), declarator->line(), symbolType);
+        checkIsBelowStructNestingLimit(typeSpecifier.getLine(), *field);
+        fieldList->push_back(field);
+    }
+
+    return fieldList;
+}
+
+TTypeSpecifierNonArray TParseContext::addStructure(const TSourceLoc &structLine,
+                                                   const TSourceLoc &nameLine,
+                                                   const ImmutableString &structName,
+                                                   TFieldList *fieldList)
+{
+    SymbolType structSymbolType = SymbolType::UserDefined;
+    if (structName.empty())
+    {
+        structSymbolType = SymbolType::Empty;
+    }
+    TStructure *structure = new TStructure(&symbolTable, structName, fieldList, structSymbolType);
+
+    // Store a bool in the struct if we're at global scope, to allow us to
+    // skip the local struct scoping workaround in HLSL.
+    structure->setAtGlobalScope(symbolTable.atGlobalLevel());
+
+    if (structSymbolType != SymbolType::Empty)
+    {
+        checkIsNotReserved(nameLine, structName);
+        if (!symbolTable.declare(structure))
+        {
+            error(nameLine, "redefinition of a struct", structName);
+        }
+    }
+
+    // ensure we do not specify any storage qualifiers on the struct members
+    for (unsigned int typeListIndex = 0; typeListIndex < fieldList->size(); typeListIndex++)
+    {
+        TField &field              = *(*fieldList)[typeListIndex];
+        const TQualifier qualifier = field.type()->getQualifier();
+        switch (qualifier)
+        {
+            case EvqGlobal:
+            case EvqTemporary:
+                break;
+            default:
+                error(field.line(), "invalid qualifier on struct member",
+                      getQualifierString(qualifier));
+                break;
+        }
+        if (field.type()->isInvariant())
+        {
+            error(field.line(), "invalid qualifier on struct member", "invariant");
+        }
+        // ESSL 3.10 section 4.1.8 -- atomic_uint or images are not allowed as structure member.
+        // ANGLE_shader_pixel_local_storage also disallows PLS as struct members.
+        if (IsImage(field.type()->getBasicType()) ||
+            IsAtomicCounter(field.type()->getBasicType()) ||
+            IsPixelLocal(field.type()->getBasicType()))
+        {
+            error(field.line(), "disallowed type in struct", field.type()->getBasicString());
+        }
+
+        checkIsNotUnsizedArray(field.line(), "array members of structs must specify a size",
+                               field.name(), field.type());
+
+        checkMemoryQualifierIsNotSpecified(field.type()->getMemoryQualifier(), field.line());
+
+        checkIndexIsNotSpecified(field.line(), field.type()->getLayoutQualifier().index);
+
+        checkBindingIsNotSpecified(field.line(), field.type()->getLayoutQualifier().binding);
+
+        checkLocationIsNotSpecified(field.line(), field.type()->getLayoutQualifier());
+    }
+
+    TTypeSpecifierNonArray typeSpecifierNonArray;
+    typeSpecifierNonArray.initializeStruct(structure, true, structLine);
+    exitStructDeclaration();
+
+    return typeSpecifierNonArray;
+}
+
+TIntermSwitch *TParseContext::addSwitch(TIntermTyped *init,
+                                        TIntermBlock *statementList,
+                                        const TSourceLoc &loc)
+{
+    TBasicType switchType = init->getBasicType();
+    if ((switchType != EbtInt && switchType != EbtUInt) || init->isMatrix() || init->isArray() ||
+        init->isVector())
+    {
+        error(init->getLine(), "init-expression in a switch statement must be a scalar integer",
+              "switch");
+        return nullptr;
+    }
+
+    ASSERT(statementList);
+    if (!ValidateSwitchStatementList(switchType, mDiagnostics, statementList, loc))
+    {
+        ASSERT(mDiagnostics->numErrors() > 0);
+        return nullptr;
+    }
+
+    markStaticReadIfSymbol(init);
+    TIntermSwitch *node = new TIntermSwitch(init, statementList);
+    node->setLine(loc);
+    return node;
+}
+
+TIntermCase *TParseContext::addCase(TIntermTyped *condition, const TSourceLoc &loc)
+{
+    if (mSwitchNestingLevel == 0)
+    {
+        error(loc, "case labels need to be inside switch statements", "case");
+        return nullptr;
+    }
+    if (condition == nullptr)
+    {
+        error(loc, "case label must have a condition", "case");
+        return nullptr;
+    }
+    if ((condition->getBasicType() != EbtInt && condition->getBasicType() != EbtUInt) ||
+        condition->isMatrix() || condition->isArray() || condition->isVector())
+    {
+        error(condition->getLine(), "case label must be a scalar integer", "case");
+    }
+    TIntermConstantUnion *conditionConst = condition->getAsConstantUnion();
+    // ANGLE should be able to fold any EvqConst expressions resulting in an integer - but to be
+    // safe against corner cases we still check for conditionConst. Some interpretations of the
+    // spec have allowed constant expressions with side effects - like array length() method on a
+    // non-constant array.
+    if (condition->getQualifier() != EvqConst || conditionConst == nullptr)
+    {
+        error(condition->getLine(), "case label must be constant", "case");
+    }
+    TIntermCase *node = new TIntermCase(condition);
+    node->setLine(loc);
+    return node;
+}
+
+TIntermCase *TParseContext::addDefault(const TSourceLoc &loc)
+{
+    if (mSwitchNestingLevel == 0)
+    {
+        error(loc, "default labels need to be inside switch statements", "default");
+        return nullptr;
+    }
+    TIntermCase *node = new TIntermCase(nullptr);
+    node->setLine(loc);
+    return node;
+}
+
+TIntermTyped *TParseContext::createUnaryMath(TOperator op,
+                                             TIntermTyped *child,
+                                             const TSourceLoc &loc,
+                                             const TFunction *func)
+{
+    ASSERT(child != nullptr);
+
+    switch (op)
+    {
+        case EOpLogicalNot:
+            if (child->getBasicType() != EbtBool || child->isMatrix() || child->isArray() ||
+                child->isVector())
+            {
+                unaryOpError(loc, GetOperatorString(op), child->getType());
+                return nullptr;
+            }
+            break;
+        case EOpBitwiseNot:
+            if ((child->getBasicType() != EbtInt && child->getBasicType() != EbtUInt) ||
+                child->isMatrix() || child->isArray())
+            {
+                unaryOpError(loc, GetOperatorString(op), child->getType());
+                return nullptr;
+            }
+            break;
+        case EOpPostIncrement:
+        case EOpPreIncrement:
+        case EOpPostDecrement:
+        case EOpPreDecrement:
+        case EOpNegative:
+        case EOpPositive:
+            if (child->getBasicType() == EbtStruct || child->isInterfaceBlock() ||
+                child->getBasicType() == EbtBool || child->isArray() ||
+                child->getBasicType() == EbtVoid || IsOpaqueType(child->getBasicType()))
+            {
+                unaryOpError(loc, GetOperatorString(op), child->getType());
+                return nullptr;
+            }
+            break;
+        // Operators for math built-ins are already type checked against their prototype.
+        default:
+            break;
+    }
+
+    if (child->getMemoryQualifier().writeonly)
+    {
+        const char *opStr =
+            BuiltInGroup::IsBuiltIn(op) ? func->name().data() : GetOperatorString(op);
+        unaryOpError(loc, opStr, child->getType());
+        return nullptr;
+    }
+
+    markStaticReadIfSymbol(child);
+    TIntermUnary *node = new TIntermUnary(op, child, func);
+    node->setLine(loc);
+
+    return node->fold(mDiagnostics);
+}
+
+TIntermTyped *TParseContext::addUnaryMath(TOperator op, TIntermTyped *child, const TSourceLoc &loc)
+{
+    ASSERT(op != EOpNull);
+    TIntermTyped *node = createUnaryMath(op, child, loc, nullptr);
+    if (node == nullptr)
+    {
+        return child;
+    }
+    return node;
+}
+
+TIntermTyped *TParseContext::addUnaryMathLValue(TOperator op,
+                                                TIntermTyped *child,
+                                                const TSourceLoc &loc)
+{
+    checkCanBeLValue(loc, GetOperatorString(op), child);
+    return addUnaryMath(op, child, loc);
+}
+
+TIntermTyped *TParseContext::expressionOrFoldedResult(TIntermTyped *expression)
+{
+    // If we can, we should return the folded version of the expression for subsequent parsing. This
+    // enables folding the containing expression during parsing as well, instead of the separate
+    // FoldExpressions() step where folding nested expressions requires multiple full AST
+    // traversals.
+
+    // Even if folding fails the fold() functions return some node representing the expression,
+    // typically the original node. So "folded" can be assumed to be non-null.
+    TIntermTyped *folded = expression->fold(mDiagnostics);
+    ASSERT(folded != nullptr);
+    if (folded->getQualifier() == expression->getQualifier())
+    {
+        // We need this expression to have the correct qualifier when validating the consuming
+        // expression. So we can only return the folded node from here in case it has the same
+        // qualifier as the original expression. In this kind of a cases the qualifier of the folded
+        // node is EvqConst, whereas the qualifier of the expression is EvqTemporary:
+        //  1. (true ? 1.0 : non_constant)
+        //  2. (non_constant, 1.0)
+        return folded;
+    }
+    return expression;
+}
+
+bool TParseContext::binaryOpCommonCheck(TOperator op,
+                                        TIntermTyped *left,
+                                        TIntermTyped *right,
+                                        const TSourceLoc &loc)
+{
+    // Check opaque types are not allowed to be operands in expressions other than array indexing
+    // and structure member selection.
+    if (IsOpaqueType(left->getBasicType()) || IsOpaqueType(right->getBasicType()))
+    {
+        switch (op)
+        {
+            case EOpIndexDirect:
+            case EOpIndexIndirect:
+                break;
+
+            default:
+                ASSERT(op != EOpIndexDirectStruct);
+                error(loc, "Invalid operation for variables with an opaque type",
+                      GetOperatorString(op));
+                return false;
+        }
+    }
+
+    if (right->getMemoryQualifier().writeonly)
+    {
+        error(loc, "Invalid operation for variables with writeonly", GetOperatorString(op));
+        return false;
+    }
+
+    if (left->getMemoryQualifier().writeonly)
+    {
+        switch (op)
+        {
+            case EOpAssign:
+            case EOpInitialize:
+            case EOpIndexDirect:
+            case EOpIndexIndirect:
+            case EOpIndexDirectStruct:
+            case EOpIndexDirectInterfaceBlock:
+                break;
+            default:
+                error(loc, "Invalid operation for variables with writeonly", GetOperatorString(op));
+                return false;
+        }
+    }
+
+    if (left->getType().getStruct() || right->getType().getStruct())
+    {
+        switch (op)
+        {
+            case EOpIndexDirectStruct:
+                ASSERT(left->getType().getStruct());
+                break;
+            case EOpEqual:
+            case EOpNotEqual:
+            case EOpAssign:
+            case EOpInitialize:
+                if (left->getType() != right->getType())
+                {
+                    return false;
+                }
+                break;
+            default:
+                error(loc, "Invalid operation for structs", GetOperatorString(op));
+                return false;
+        }
+    }
+
+    if (left->isInterfaceBlock() || right->isInterfaceBlock())
+    {
+        switch (op)
+        {
+            case EOpIndexDirectInterfaceBlock:
+                ASSERT(left->getType().getInterfaceBlock());
+                break;
+            default:
+                error(loc, "Invalid operation for interface blocks", GetOperatorString(op));
+                return false;
+        }
+    }
+
+    if (left->isArray() != right->isArray())
+    {
+        error(loc, "array / non-array mismatch", GetOperatorString(op));
+        return false;
+    }
+
+    if (left->isArray())
+    {
+        ASSERT(right->isArray());
+        if (mShaderVersion < 300)
+        {
+            error(loc, "Invalid operation for arrays", GetOperatorString(op));
+            return false;
+        }
+
+        switch (op)
+        {
+            case EOpEqual:
+            case EOpNotEqual:
+            case EOpAssign:
+            case EOpInitialize:
+                break;
+            default:
+                error(loc, "Invalid operation for arrays", GetOperatorString(op));
+                return false;
+        }
+        // At this point, size of implicitly sized arrays should be resolved.
+        if (left->getType().getArraySizes() != right->getType().getArraySizes())
+        {
+            error(loc, "array size mismatch", GetOperatorString(op));
+            return false;
+        }
+    }
+
+    // Check ops which require integer / ivec parameters
+    bool isBitShift = false;
+    switch (op)
+    {
+        case EOpBitShiftLeft:
+        case EOpBitShiftRight:
+        case EOpBitShiftLeftAssign:
+        case EOpBitShiftRightAssign:
+            // Unsigned can be bit-shifted by signed and vice versa, but we need to
+            // check that the basic type is an integer type.
+            isBitShift = true;
+            if (!IsInteger(left->getBasicType()) || !IsInteger(right->getBasicType()))
+            {
+                return false;
+            }
+            break;
+        case EOpBitwiseAnd:
+        case EOpBitwiseXor:
+        case EOpBitwiseOr:
+        case EOpBitwiseAndAssign:
+        case EOpBitwiseXorAssign:
+        case EOpBitwiseOrAssign:
+            // It is enough to check the type of only one operand, since later it
+            // is checked that the operand types match.
+            if (!IsInteger(left->getBasicType()))
+            {
+                return false;
+            }
+            break;
+        default:
+            break;
+    }
+
+    ImplicitTypeConversion conversion = GetConversion(left->getBasicType(), right->getBasicType());
+
+    // Implicit type casting only supported for GL shaders
+    if (!isBitShift && conversion != ImplicitTypeConversion::Same &&
+        (!IsDesktopGLSpec(mShaderSpec) || !IsValidImplicitConversion(conversion, op)))
+    {
+        return false;
+    }
+
+    // Check that:
+    // 1. Type sizes match exactly on ops that require that.
+    // 2. Restrictions for structs that contain arrays or samplers are respected.
+    // 3. Arithmetic op type dimensionality restrictions for ops other than multiply are respected.
+    switch (op)
+    {
+        case EOpAssign:
+        case EOpInitialize:
+        case EOpEqual:
+        case EOpNotEqual:
+            // ESSL 1.00 sections 5.7, 5.8, 5.9
+            if (mShaderVersion < 300 && left->getType().isStructureContainingArrays())
+            {
+                error(loc, "undefined operation for structs containing arrays",
+                      GetOperatorString(op));
+                return false;
+            }
+            // Samplers as l-values are disallowed also in ESSL 3.00, see section 4.1.7,
+            // we interpret the spec so that this extends to structs containing samplers,
+            // similarly to ESSL 1.00 spec.
+            if ((mShaderVersion < 300 || op == EOpAssign || op == EOpInitialize) &&
+                left->getType().isStructureContainingSamplers())
+            {
+                error(loc, "undefined operation for structs containing samplers",
+                      GetOperatorString(op));
+                return false;
+            }
+
+            if ((left->getNominalSize() != right->getNominalSize()) ||
+                (left->getSecondarySize() != right->getSecondarySize()))
+            {
+                error(loc, "dimension mismatch", GetOperatorString(op));
+                return false;
+            }
+            break;
+        case EOpLessThan:
+        case EOpGreaterThan:
+        case EOpLessThanEqual:
+        case EOpGreaterThanEqual:
+            if (!left->isScalar() || !right->isScalar())
+            {
+                error(loc, "comparison operator only defined for scalars", GetOperatorString(op));
+                return false;
+            }
+            break;
+        case EOpAdd:
+        case EOpSub:
+        case EOpDiv:
+        case EOpIMod:
+        case EOpBitShiftLeft:
+        case EOpBitShiftRight:
+        case EOpBitwiseAnd:
+        case EOpBitwiseXor:
+        case EOpBitwiseOr:
+        case EOpAddAssign:
+        case EOpSubAssign:
+        case EOpDivAssign:
+        case EOpIModAssign:
+        case EOpBitShiftLeftAssign:
+        case EOpBitShiftRightAssign:
+        case EOpBitwiseAndAssign:
+        case EOpBitwiseXorAssign:
+        case EOpBitwiseOrAssign:
+            if ((left->isMatrix() && right->isVector()) || (left->isVector() && right->isMatrix()))
+            {
+                return false;
+            }
+
+            // Are the sizes compatible?
+            if (left->getNominalSize() != right->getNominalSize() ||
+                left->getSecondarySize() != right->getSecondarySize())
+            {
+                // If the nominal sizes of operands do not match:
+                // One of them must be a scalar.
+                if (!left->isScalar() && !right->isScalar())
+                    return false;
+
+                // In the case of compound assignment other than multiply-assign,
+                // the right side needs to be a scalar. Otherwise a vector/matrix
+                // would be assigned to a scalar. A scalar can't be shifted by a
+                // vector either.
+                if (!right->isScalar() &&
+                    (IsAssignment(op) || op == EOpBitShiftLeft || op == EOpBitShiftRight))
+                    return false;
+            }
+            break;
+        default:
+            break;
+    }
+
+    return true;
+}
+
+bool TParseContext::isMultiplicationTypeCombinationValid(TOperator op,
+                                                         const TType &left,
+                                                         const TType &right)
+{
+    switch (op)
+    {
+        case EOpMul:
+        case EOpMulAssign:
+            return left.getNominalSize() == right.getNominalSize() &&
+                   left.getSecondarySize() == right.getSecondarySize();
+        case EOpVectorTimesScalar:
+            return true;
+        case EOpVectorTimesScalarAssign:
+            ASSERT(!left.isMatrix() && !right.isMatrix());
+            return left.isVector() && !right.isVector();
+        case EOpVectorTimesMatrix:
+            return left.getNominalSize() == right.getRows();
+        case EOpVectorTimesMatrixAssign:
+            ASSERT(!left.isMatrix() && right.isMatrix());
+            return left.isVector() && left.getNominalSize() == right.getRows() &&
+                   left.getNominalSize() == right.getCols();
+        case EOpMatrixTimesVector:
+            return left.getCols() == right.getNominalSize();
+        case EOpMatrixTimesScalar:
+            return true;
+        case EOpMatrixTimesScalarAssign:
+            ASSERT(left.isMatrix() && !right.isMatrix());
+            return !right.isVector();
+        case EOpMatrixTimesMatrix:
+            return left.getCols() == right.getRows();
+        case EOpMatrixTimesMatrixAssign:
+            ASSERT(left.isMatrix() && right.isMatrix());
+            // We need to check two things:
+            // 1. The matrix multiplication step is valid.
+            // 2. The result will have the same number of columns as the lvalue.
+            return left.getCols() == right.getRows() && left.getCols() == right.getCols();
+
+        default:
+            UNREACHABLE();
+            return false;
+    }
+}
+
+TIntermTyped *TParseContext::addBinaryMathInternal(TOperator op,
+                                                   TIntermTyped *left,
+                                                   TIntermTyped *right,
+                                                   const TSourceLoc &loc)
+{
+    if (!binaryOpCommonCheck(op, left, right, loc))
+        return nullptr;
+
+    switch (op)
+    {
+        case EOpEqual:
+        case EOpNotEqual:
+        case EOpLessThan:
+        case EOpGreaterThan:
+        case EOpLessThanEqual:
+        case EOpGreaterThanEqual:
+            break;
+        case EOpLogicalOr:
+        case EOpLogicalXor:
+        case EOpLogicalAnd:
+            ASSERT(!left->isArray() && !right->isArray() && !left->getType().getStruct() &&
+                   !right->getType().getStruct());
+            if (left->getBasicType() != EbtBool || !left->isScalar() || !right->isScalar())
+            {
+                return nullptr;
+            }
+            // Basic types matching should have been already checked.
+            ASSERT(right->getBasicType() == EbtBool);
+            break;
+        case EOpAdd:
+        case EOpSub:
+        case EOpDiv:
+        case EOpMul:
+            ASSERT(!left->isArray() && !right->isArray() && !left->getType().getStruct() &&
+                   !right->getType().getStruct());
+            if (left->getBasicType() == EbtBool)
+            {
+                return nullptr;
+            }
+            break;
+        case EOpIMod:
+            ASSERT(!left->isArray() && !right->isArray() && !left->getType().getStruct() &&
+                   !right->getType().getStruct());
+            // Note that this is only for the % operator, not for mod()
+            if (left->getBasicType() == EbtBool || left->getBasicType() == EbtFloat)
+            {
+                return nullptr;
+            }
+            break;
+        default:
+            break;
+    }
+
+    if (op == EOpMul)
+    {
+        op = TIntermBinary::GetMulOpBasedOnOperands(left->getType(), right->getType());
+        if (!isMultiplicationTypeCombinationValid(op, left->getType(), right->getType()))
+        {
+            return nullptr;
+        }
+    }
+
+    TIntermBinary *node = new TIntermBinary(op, left, right);
+    ASSERT(op != EOpAssign);
+    markStaticReadIfSymbol(left);
+    markStaticReadIfSymbol(right);
+    node->setLine(loc);
+    return expressionOrFoldedResult(node);
+}
+
+TIntermTyped *TParseContext::addBinaryMath(TOperator op,
+                                           TIntermTyped *left,
+                                           TIntermTyped *right,
+                                           const TSourceLoc &loc)
+{
+    TIntermTyped *node = addBinaryMathInternal(op, left, right, loc);
+    if (node == 0)
+    {
+        binaryOpError(loc, GetOperatorString(op), left->getType(), right->getType());
+        return left;
+    }
+    return node;
+}
+
+TIntermTyped *TParseContext::addBinaryMathBooleanResult(TOperator op,
+                                                        TIntermTyped *left,
+                                                        TIntermTyped *right,
+                                                        const TSourceLoc &loc)
+{
+    TIntermTyped *node = addBinaryMathInternal(op, left, right, loc);
+    if (node == nullptr)
+    {
+        binaryOpError(loc, GetOperatorString(op), left->getType(), right->getType());
+        node = CreateBoolNode(false);
+        node->setLine(loc);
+    }
+    return node;
+}
+
+TIntermTyped *TParseContext::addAssign(TOperator op,
+                                       TIntermTyped *left,
+                                       TIntermTyped *right,
+                                       const TSourceLoc &loc)
+{
+    checkCanBeLValue(loc, "assign", left);
+    TIntermBinary *node = nullptr;
+    if (binaryOpCommonCheck(op, left, right, loc))
+    {
+        TIntermBinary *lValue = left->getAsBinaryNode();
+        if ((lValue != nullptr) &&
+            (lValue->getOp() == EOpIndexIndirect || lValue->getOp() == EOpIndexDirect) &&
+            IsTessellationControlShaderOutput(mShaderType, lValue->getLeft()->getQualifier()))
+        {
+            checkTCSOutVarIndexIsValid(lValue, loc);
+        }
+
+        if (op == EOpMulAssign)
+        {
+            op = TIntermBinary::GetMulAssignOpBasedOnOperands(left->getType(), right->getType());
+            if (isMultiplicationTypeCombinationValid(op, left->getType(), right->getType()))
+            {
+                node = new TIntermBinary(op, left, right);
+            }
+        }
+        else
+        {
+            node = new TIntermBinary(op, left, right);
+        }
+    }
+    if (node == nullptr)
+    {
+        assignError(loc, "assign", left->getType(), right->getType());
+        return left;
+    }
+    if (op != EOpAssign)
+    {
+        markStaticReadIfSymbol(left);
+    }
+    markStaticReadIfSymbol(right);
+    node->setLine(loc);
+    return node;
+}
+
+TIntermTyped *TParseContext::addComma(TIntermTyped *left,
+                                      TIntermTyped *right,
+                                      const TSourceLoc &loc)
+{
+    // WebGL2 section 5.26, the following results in an error:
+    // "Sequence operator applied to void, arrays, or structs containing arrays"
+    if (mShaderSpec == SH_WEBGL2_SPEC &&
+        (left->isArray() || left->getBasicType() == EbtVoid ||
+         left->getType().isStructureContainingArrays() || right->isArray() ||
+         right->getBasicType() == EbtVoid || right->getType().isStructureContainingArrays()))
+    {
+        error(loc,
+              "sequence operator is not allowed for void, arrays, or structs containing arrays",
+              ",");
+    }
+
+    TIntermBinary *commaNode = TIntermBinary::CreateComma(left, right, mShaderVersion);
+    markStaticReadIfSymbol(left);
+    markStaticReadIfSymbol(right);
+    commaNode->setLine(loc);
+
+    return expressionOrFoldedResult(commaNode);
+}
+
+TIntermBranch *TParseContext::addBranch(TOperator op, const TSourceLoc &loc)
+{
+    switch (op)
+    {
+        case EOpContinue:
+            if (mLoopNestingLevel <= 0)
+            {
+                error(loc, "continue statement only allowed in loops", "");
+            }
+            break;
+        case EOpBreak:
+            if (mLoopNestingLevel <= 0 && mSwitchNestingLevel <= 0)
+            {
+                error(loc, "break statement only allowed in loops and switch statements", "");
+            }
+            break;
+        case EOpReturn:
+            if (mCurrentFunctionType->getBasicType() != EbtVoid)
+            {
+                error(loc, "non-void function must return a value", "return");
+            }
+            if (mDeclaringMain)
+            {
+                errorIfPLSDeclared(loc, PLSIllegalOperations::ReturnFromMain);
+            }
+            break;
+        case EOpKill:
+            if (mShaderType != GL_FRAGMENT_SHADER)
+            {
+                error(loc, "discard supported in fragment shaders only", "discard");
+            }
+            else
+            {
+                errorIfPLSDeclared(loc, PLSIllegalOperations::Discard);
+            }
+            mHasDiscard = true;
+            break;
+        default:
+            UNREACHABLE();
+            break;
+    }
+    return addBranch(op, nullptr, loc);
+}
+
+TIntermBranch *TParseContext::addBranch(TOperator op,
+                                        TIntermTyped *expression,
+                                        const TSourceLoc &loc)
+{
+    if (expression != nullptr)
+    {
+        markStaticReadIfSymbol(expression);
+        ASSERT(op == EOpReturn);
+        mFunctionReturnsValue = true;
+        if (mCurrentFunctionType->getBasicType() == EbtVoid)
+        {
+            error(loc, "void function cannot return a value", "return");
+        }
+        else if (*mCurrentFunctionType != expression->getType())
+        {
+            error(loc, "function return is not matching type:", "return");
+        }
+    }
+    TIntermBranch *node = new TIntermBranch(op, expression);
+    node->setLine(loc);
+    return node;
+}
+
+void TParseContext::appendStatement(TIntermBlock *block, TIntermNode *statement)
+{
+    if (statement != nullptr)
+    {
+        markStaticReadIfSymbol(statement);
+        block->appendStatement(statement);
+    }
+}
+
+void TParseContext::checkTextureGather(TIntermAggregate *functionCall)
+{
+    const TOperator op    = functionCall->getOp();
+    const TFunction *func = functionCall->getFunction();
+    if (BuiltInGroup::IsTextureGather(op))
+    {
+        bool isTextureGatherOffsetOrOffsets =
+            BuiltInGroup::IsTextureGatherOffset(op) || BuiltInGroup::IsTextureGatherOffsets(op);
+        TIntermNode *componentNode = nullptr;
+        TIntermSequence *arguments = functionCall->getSequence();
+        ASSERT(arguments->size() >= 2u && arguments->size() <= 4u);
+        const TIntermTyped *sampler = arguments->front()->getAsTyped();
+        ASSERT(sampler != nullptr);
+        switch (sampler->getBasicType())
+        {
+            case EbtSampler2D:
+            case EbtISampler2D:
+            case EbtUSampler2D:
+            case EbtSampler2DArray:
+            case EbtISampler2DArray:
+            case EbtUSampler2DArray:
+                if ((!isTextureGatherOffsetOrOffsets && arguments->size() == 3u) ||
+                    (isTextureGatherOffsetOrOffsets && arguments->size() == 4u))
+                {
+                    componentNode = arguments->back();
+                }
+                break;
+            case EbtSamplerCube:
+            case EbtISamplerCube:
+            case EbtUSamplerCube:
+            case EbtSamplerCubeArray:
+            case EbtISamplerCubeArray:
+            case EbtUSamplerCubeArray:
+                ASSERT(!isTextureGatherOffsetOrOffsets);
+                if (arguments->size() == 3u)
+                {
+                    componentNode = arguments->back();
+                }
+                break;
+            case EbtSampler2DShadow:
+            case EbtSampler2DArrayShadow:
+            case EbtSamplerCubeShadow:
+            case EbtSamplerCubeArrayShadow:
+                break;
+            default:
+                UNREACHABLE();
+                break;
+        }
+        if (componentNode)
+        {
+            const TIntermConstantUnion *componentConstantUnion =
+                componentNode->getAsConstantUnion();
+            if (componentNode->getAsTyped()->getQualifier() != EvqConst || !componentConstantUnion)
+            {
+                error(functionCall->getLine(), "Texture component must be a constant expression",
+                      func->name());
+            }
+            else
+            {
+                int component = componentConstantUnion->getIConst(0);
+                if (component < 0 || component > 3)
+                {
+                    error(functionCall->getLine(), "Component must be in the range [0;3]",
+                          func->name());
+                }
+            }
+        }
+    }
+}
+
+void TParseContext::checkTextureOffset(TIntermAggregate *functionCall)
+{
+    const TOperator op         = functionCall->getOp();
+    const TFunction *func      = functionCall->getFunction();
+    TIntermNode *offset        = nullptr;
+    TIntermSequence *arguments = functionCall->getSequence();
+
+    if (BuiltInGroup::IsTextureOffsetNoBias(op) || BuiltInGroup::IsTextureGatherOffsetNoComp(op) ||
+        BuiltInGroup::IsTextureGatherOffsetsNoComp(op))
+    {
+        offset = arguments->back();
+    }
+    else if (BuiltInGroup::IsTextureOffsetBias(op) || BuiltInGroup::IsTextureGatherOffsetComp(op) ||
+             BuiltInGroup::IsTextureGatherOffsetsComp(op))
+    {
+        // A bias or comp parameter follows the offset parameter.
+        ASSERT(arguments->size() >= 3);
+        offset = (*arguments)[2];
+    }
+
+    // If not one of the above built-ins, there's nothing to do here.
+    if (offset == nullptr)
+    {
+        return;
+    }
+
+    bool isTextureGatherOffset             = BuiltInGroup::IsTextureGatherOffset(op);
+    bool isTextureGatherOffsets            = BuiltInGroup::IsTextureGatherOffsets(op);
+    bool useTextureGatherOffsetConstraints = isTextureGatherOffset || isTextureGatherOffsets;
+
+    int minOffsetValue =
+        useTextureGatherOffsetConstraints ? mMinProgramTextureGatherOffset : mMinProgramTexelOffset;
+    int maxOffsetValue =
+        useTextureGatherOffsetConstraints ? mMaxProgramTextureGatherOffset : mMaxProgramTexelOffset;
+
+    if (isTextureGatherOffsets)
+    {
+        // If textureGatherOffsets, the offsets parameter is an array, which is expected as an
+        // aggregate constructor node or as a symbol node with a constant value.
+        TIntermAggregate *offsetAggregate = offset->getAsAggregate();
+        TIntermSymbol *offsetSymbol       = offset->getAsSymbolNode();
+
+        const TConstantUnion *offsetValues = offsetAggregate ? offsetAggregate->getConstantValue()
+                                             : offsetSymbol  ? offsetSymbol->getConstantValue()
+                                                             : nullptr;
+
+        if (offsetValues == nullptr)
+        {
+            error(functionCall->getLine(), "Texture offsets must be a constant expression",
+                  func->name());
+            return;
+        }
+
+        constexpr unsigned int kOffsetsCount = 4;
+        const TType &offsetType =
+            offsetAggregate != nullptr ? offsetAggregate->getType() : offsetSymbol->getType();
+        if (offsetType.getNumArraySizes() != 1 || offsetType.getArraySizes()[0] != kOffsetsCount)
+        {
+            error(functionCall->getLine(), "Texture offsets must be an array of 4 elements",
+                  func->name());
+            return;
+        }
+
+        size_t size = offsetType.getObjectSize() / kOffsetsCount;
+        for (unsigned int i = 0; i < kOffsetsCount; ++i)
+        {
+            checkSingleTextureOffset(offset->getLine(), &offsetValues[i * size], size,
+                                     minOffsetValue, maxOffsetValue);
+        }
+    }
+    else
+    {
+        // If textureOffset or textureGatherOffset, the offset is expected to be found as a constant
+        // union.
+        TIntermConstantUnion *offsetConstantUnion = offset->getAsConstantUnion();
+
+        // ES3.2 or ES3.1's EXT_gpu_shader5 allow non-const offsets to be passed to
+        // textureGatherOffset.
+        bool textureGatherOffsetMustBeConst =
+            mShaderVersion <= 310 && !isExtensionEnabled(TExtension::EXT_gpu_shader5);
+
+        bool isOffsetConst =
+            offset->getAsTyped()->getQualifier() == EvqConst && offsetConstantUnion != nullptr;
+        bool offsetMustBeConst = !isTextureGatherOffset || textureGatherOffsetMustBeConst;
+
+        if (!isOffsetConst && offsetMustBeConst)
+        {
+            error(functionCall->getLine(), "Texture offset must be a constant expression",
+                  func->name());
+            return;
+        }
+
+        // We cannot verify non-constant offsets to textureGatherOffset.
+        if (offsetConstantUnion == nullptr)
+        {
+            ASSERT(!offsetMustBeConst);
+            return;
+        }
+
+        size_t size                  = offsetConstantUnion->getType().getObjectSize();
+        const TConstantUnion *values = offsetConstantUnion->getConstantValue();
+        checkSingleTextureOffset(offset->getLine(), values, size, minOffsetValue, maxOffsetValue);
+    }
+}
+
+void TParseContext::checkSingleTextureOffset(const TSourceLoc &line,
+                                             const TConstantUnion *values,
+                                             size_t size,
+                                             int minOffsetValue,
+                                             int maxOffsetValue)
+{
+    for (size_t i = 0u; i < size; ++i)
+    {
+        ASSERT(values[i].getType() == EbtInt);
+        int offsetValue = values[i].getIConst();
+        if (offsetValue > maxOffsetValue || offsetValue < minOffsetValue)
+        {
+            std::stringstream tokenStream = sh::InitializeStream<std::stringstream>();
+            tokenStream << offsetValue;
+            std::string token = tokenStream.str();
+            error(line, "Texture offset value out of valid range", token.c_str());
+        }
+    }
+}
+
+void TParseContext::checkInterpolationFS(TIntermAggregate *functionCall)
+{
+    const TFunction *func = functionCall->getFunction();
+    if (!BuiltInGroup::IsInterpolationFS(functionCall->getOp()))
+    {
+        return;
+    }
+
+    TIntermTyped *arg0 = nullptr;
+
+    if (functionCall->getAsAggregate())
+    {
+        const TIntermSequence *argp = functionCall->getSequence();
+        if (argp->size() > 0)
+            arg0 = (*argp)[0]->getAsTyped();
+    }
+    else
+    {
+        assert(functionCall->getAsUnaryNode());
+        arg0 = functionCall->getAsUnaryNode()->getOperand();
+    }
+
+    // Make sure the first argument is an interpolant, or an array element of an interpolant
+    if (!IsVaryingIn(arg0->getType().getQualifier()))
+    {
+        // It might still be an array element.
+        const TIntermTyped *base = FindLValueBase(arg0);
+
+        if (base == nullptr || (!IsVaryingIn(base->getType().getQualifier())))
+            error(arg0->getLine(),
+                  "first argument must be an interpolant, or interpolant-array element",
+                  func->name());
+    }
+}
+
+void TParseContext::checkAtomicMemoryBuiltinFunctions(TIntermAggregate *functionCall)
+{
+    const TFunction *func = functionCall->getFunction();
+    if (BuiltInGroup::IsAtomicMemory(functionCall->getOp()))
+    {
+        TIntermSequence *arguments = functionCall->getSequence();
+        TIntermTyped *memNode      = (*arguments)[0]->getAsTyped();
+
+        if (IsBufferOrSharedVariable(memNode))
+        {
+            return;
+        }
+
+        while (memNode->getAsBinaryNode() || memNode->getAsSwizzleNode())
+        {
+            // Child 0 is "left" if binary, and the expression being swizzled if swizzle.
+            // Note: we don't need to check that the binary operation is one of EOp*Index*, as any
+            // other operation will result in a temp value which cannot be passed to this
+            // out/inout parameter anyway.
+            memNode = memNode->getChildNode(0)->getAsTyped();
+            if (IsBufferOrSharedVariable(memNode))
+            {
+                return;
+            }
+        }
+
+        error(memNode->getLine(),
+              "The value passed to the mem argument of an atomic memory function does not "
+              "correspond to a buffer or shared variable.",
+              func->name());
+    }
+}
+
+// GLSL ES 3.10 Revision 4, 4.9 Memory Access Qualifiers
+void TParseContext::checkImageMemoryAccessForBuiltinFunctions(TIntermAggregate *functionCall)
+{
+    const TOperator op = functionCall->getOp();
+
+    if (BuiltInGroup::IsImage(op))
+    {
+        TIntermSequence *arguments = functionCall->getSequence();
+        TIntermTyped *imageNode    = (*arguments)[0]->getAsTyped();
+
+        const TMemoryQualifier &memoryQualifier = imageNode->getMemoryQualifier();
+
+        if (BuiltInGroup::IsImageStore(op))
+        {
+            if (memoryQualifier.readonly)
+            {
+                error(imageNode->getLine(),
+                      "'imageStore' cannot be used with images qualified as 'readonly'",
+                      GetImageArgumentToken(imageNode));
+            }
+        }
+        else if (BuiltInGroup::IsImageLoad(op))
+        {
+            if (memoryQualifier.writeonly)
+            {
+                error(imageNode->getLine(),
+                      "'imageLoad' cannot be used with images qualified as 'writeonly'",
+                      GetImageArgumentToken(imageNode));
+            }
+        }
+        else if (BuiltInGroup::IsImageAtomic(op))
+        {
+            if (memoryQualifier.readonly)
+            {
+                error(imageNode->getLine(),
+                      "'imageAtomic' cannot be used with images qualified as 'readonly'",
+                      GetImageArgumentToken(imageNode));
+            }
+            if (memoryQualifier.writeonly)
+            {
+                error(imageNode->getLine(),
+                      "'imageAtomic' cannot be used with images qualified as 'writeonly'",
+                      GetImageArgumentToken(imageNode));
+            }
+        }
+    }
+}
+
+// GLSL ES 3.10 Revision 4, 13.51 Matching of Memory Qualifiers in Function Parameters
+void TParseContext::checkImageMemoryAccessForUserDefinedFunctions(
+    const TFunction *functionDefinition,
+    const TIntermAggregate *functionCall)
+{
+    ASSERT(functionCall->getOp() == EOpCallFunctionInAST);
+
+    const TIntermSequence &arguments = *functionCall->getSequence();
+
+    ASSERT(functionDefinition->getParamCount() == arguments.size());
+
+    for (size_t i = 0; i < arguments.size(); ++i)
+    {
+        TIntermTyped *typedArgument        = arguments[i]->getAsTyped();
+        const TType &functionArgumentType  = typedArgument->getType();
+        const TType &functionParameterType = functionDefinition->getParam(i)->getType();
+        ASSERT(functionArgumentType.getBasicType() == functionParameterType.getBasicType());
+
+        if (IsImage(functionArgumentType.getBasicType()))
+        {
+            const TMemoryQualifier &functionArgumentMemoryQualifier =
+                functionArgumentType.getMemoryQualifier();
+            const TMemoryQualifier &functionParameterMemoryQualifier =
+                functionParameterType.getMemoryQualifier();
+            if (functionArgumentMemoryQualifier.readonly &&
+                !functionParameterMemoryQualifier.readonly)
+            {
+                error(functionCall->getLine(),
+                      "Function call discards the 'readonly' qualifier from image",
+                      GetImageArgumentToken(typedArgument));
+            }
+
+            if (functionArgumentMemoryQualifier.writeonly &&
+                !functionParameterMemoryQualifier.writeonly)
+            {
+                error(functionCall->getLine(),
+                      "Function call discards the 'writeonly' qualifier from image",
+                      GetImageArgumentToken(typedArgument));
+            }
+
+            if (functionArgumentMemoryQualifier.coherent &&
+                !functionParameterMemoryQualifier.coherent)
+            {
+                error(functionCall->getLine(),
+                      "Function call discards the 'coherent' qualifier from image",
+                      GetImageArgumentToken(typedArgument));
+            }
+
+            if (functionArgumentMemoryQualifier.volatileQualifier &&
+                !functionParameterMemoryQualifier.volatileQualifier)
+            {
+                error(functionCall->getLine(),
+                      "Function call discards the 'volatile' qualifier from image",
+                      GetImageArgumentToken(typedArgument));
+            }
+        }
+    }
+}
+
+TIntermTyped *TParseContext::addFunctionCallOrMethod(TFunctionLookup *fnCall, const TSourceLoc &loc)
+{
+    if (fnCall->thisNode() != nullptr)
+    {
+        return addMethod(fnCall, loc);
+    }
+    if (fnCall->isConstructor())
+    {
+        return addConstructor(fnCall, loc);
+    }
+    return addNonConstructorFunctionCall(fnCall, loc);
+}
+
+TIntermTyped *TParseContext::addMethod(TFunctionLookup *fnCall, const TSourceLoc &loc)
+{
+    TIntermTyped *thisNode = fnCall->thisNode();
+    // It's possible for the name pointer in the TFunction to be null in case it gets parsed as
+    // a constructor. But such a TFunction can't reach here, since the lexer goes into FIELDS
+    // mode after a dot, which makes type identifiers to be parsed as FIELD_SELECTION instead.
+    // So accessing fnCall->name() below is safe.
+    if (fnCall->name() != "length")
+    {
+        error(loc, "invalid method", fnCall->name());
+    }
+    else if (!fnCall->arguments().empty())
+    {
+        error(loc, "method takes no parameters", "length");
+    }
+    else if (!thisNode->isArray())
+    {
+        error(loc, "length can only be called on arrays", "length");
+    }
+    else if (thisNode->getQualifier() == EvqPerVertexIn &&
+             mGeometryShaderInputPrimitiveType == EptUndefined)
+    {
+        ASSERT(mShaderType == GL_GEOMETRY_SHADER_EXT);
+        error(loc, "missing input primitive declaration before calling length on gl_in", "length");
+    }
+    else
+    {
+        TIntermUnary *node = new TIntermUnary(EOpArrayLength, thisNode, nullptr);
+        markStaticReadIfSymbol(thisNode);
+        node->setLine(loc);
+        return node->fold(mDiagnostics);
+    }
+    return CreateZeroNode(TType(EbtInt, EbpUndefined, EvqConst));
+}
+
+TIntermTyped *TParseContext::addNonConstructorFunctionCall(TFunctionLookup *fnCall,
+                                                           const TSourceLoc &loc)
+{
+    // First check whether the function has been hidden by a variable name or struct typename by
+    // using the symbol looked up in the lexical phase. If the function is not hidden, look for one
+    // with a matching argument list.
+    if (fnCall->symbol() != nullptr && !fnCall->symbol()->isFunction())
+    {
+        error(loc, "function name expected", fnCall->name());
+    }
+    else
+    {
+        // There are no inner functions, so it's enough to look for user-defined functions in the
+        // global scope.
+        const TSymbol *symbol = symbolTable.findGlobal(fnCall->getMangledName());
+
+        if (symbol == nullptr && IsDesktopGLSpec(mShaderSpec))
+        {
+            // If using Desktop GL spec, need to check for implicit conversion
+            symbol = symbolTable.findGlobalWithConversion(
+                fnCall->getMangledNamesForImplicitConversions());
+        }
+
+        if (symbol != nullptr)
+        {
+            // A user-defined function - could be an overloaded built-in as well.
+            ASSERT(symbol->symbolType() == SymbolType::UserDefined);
+            const TFunction *fnCandidate = static_cast<const TFunction *>(symbol);
+            TIntermAggregate *callNode =
+                TIntermAggregate::CreateFunctionCall(*fnCandidate, &fnCall->arguments());
+            callNode->setLine(loc);
+            checkImageMemoryAccessForUserDefinedFunctions(fnCandidate, callNode);
+            functionCallRValueLValueErrorCheck(fnCandidate, callNode);
+            return callNode;
+        }
+
+        symbol = symbolTable.findBuiltIn(fnCall->getMangledName(), mShaderVersion);
+
+        if (symbol == nullptr && IsDesktopGLSpec(mShaderSpec))
+        {
+            // If using Desktop GL spec, need to check for implicit conversion
+            symbol = symbolTable.findBuiltInWithConversion(
+                fnCall->getMangledNamesForImplicitConversions(), mShaderVersion);
+        }
+
+        if (symbol != nullptr)
+        {
+            // A built-in function.
+            ASSERT(symbol->symbolType() == SymbolType::BuiltIn);
+            const TFunction *fnCandidate = static_cast<const TFunction *>(symbol);
+
+            if (!fnCandidate->extensions().empty() &&
+                fnCandidate->extensions()[0] != TExtension::UNDEFINED)
+            {
+                checkCanUseOneOfExtensions(loc, fnCandidate->extensions());
+            }
+
+            // All function calls are mapped to a built-in operation.
+            TOperator op = fnCandidate->getBuiltInOp();
+            if (BuiltInGroup::IsMath(op) && fnCandidate->getParamCount() == 1)
+            {
+                // Treat it like a built-in unary operator.
+                TIntermNode *unaryParamNode = fnCall->arguments().front();
+                TIntermTyped *callNode =
+                    createUnaryMath(op, unaryParamNode->getAsTyped(), loc, fnCandidate);
+                ASSERT(callNode != nullptr);
+                return callNode;
+            }
+
+            TIntermAggregate *callNode =
+                TIntermAggregate::CreateBuiltInFunctionCall(*fnCandidate, &fnCall->arguments());
+            callNode->setLine(loc);
+
+            checkAtomicMemoryBuiltinFunctions(callNode);
+            checkTextureOffset(callNode);
+            checkTextureGather(callNode);
+            checkInterpolationFS(callNode);
+            checkImageMemoryAccessForBuiltinFunctions(callNode);
+
+            // Some built-in functions have out parameters too.
+            functionCallRValueLValueErrorCheck(fnCandidate, callNode);
+
+            // See if we can constant fold a built-in. Note that this may be possible
+            // even if it is not const-qualified.
+            return callNode->fold(mDiagnostics);
+        }
+        else
+        {
+            error(loc, "no matching overloaded function found", fnCall->name());
+        }
+    }
+
+    // Error message was already written. Put on an unused node for error recovery.
+    return CreateZeroNode(TType(EbtFloat, EbpMedium, EvqConst));
+}
+
+TIntermTyped *TParseContext::addTernarySelection(TIntermTyped *cond,
+                                                 TIntermTyped *trueExpression,
+                                                 TIntermTyped *falseExpression,
+                                                 const TSourceLoc &loc)
+{
+    if (!checkIsScalarBool(loc, cond))
+    {
+        return falseExpression;
+    }
+
+    if (trueExpression->getType() != falseExpression->getType())
+    {
+        TInfoSinkBase reasonStream;
+        reasonStream << "mismatching ternary operator operand types '" << trueExpression->getType()
+                     << " and '" << falseExpression->getType() << "'";
+        error(loc, reasonStream.c_str(), "?:");
+        return falseExpression;
+    }
+    if (IsOpaqueType(trueExpression->getBasicType()))
+    {
+        // ESSL 1.00 section 4.1.7
+        // ESSL 3.00.6 section 4.1.7
+        // Opaque/sampler types are not allowed in most types of expressions, including ternary.
+        // Note that structs containing opaque types don't need to be checked as structs are
+        // forbidden below.
+        error(loc, "ternary operator is not allowed for opaque types", "?:");
+        return falseExpression;
+    }
+
+    if (cond->getMemoryQualifier().writeonly || trueExpression->getMemoryQualifier().writeonly ||
+        falseExpression->getMemoryQualifier().writeonly)
+    {
+        error(loc, "ternary operator is not allowed for variables with writeonly", "?:");
+        return falseExpression;
+    }
+
+    // ESSL 1.00.17 sections 5.2 and 5.7:
+    // Ternary operator is not among the operators allowed for structures/arrays.
+    // ESSL 3.00.6 section 5.7:
+    // Ternary operator support is optional for arrays. No certainty that it works across all
+    // devices with struct either, so we err on the side of caution here. TODO (oetuaho@nvidia.com):
+    // Would be nice to make the spec and implementation agree completely here.
+    if (trueExpression->isArray() || trueExpression->getBasicType() == EbtStruct)
+    {
+        error(loc, "ternary operator is not allowed for structures or arrays", "?:");
+        return falseExpression;
+    }
+    if (trueExpression->getBasicType() == EbtInterfaceBlock)
+    {
+        error(loc, "ternary operator is not allowed for interface blocks", "?:");
+        return falseExpression;
+    }
+
+    // WebGL2 section 5.26, the following results in an error:
+    // "Ternary operator applied to void, arrays, or structs containing arrays"
+    if (mShaderSpec == SH_WEBGL2_SPEC && trueExpression->getBasicType() == EbtVoid)
+    {
+        error(loc, "ternary operator is not allowed for void", "?:");
+        return falseExpression;
+    }
+
+    TIntermTernary *node = new TIntermTernary(cond, trueExpression, falseExpression);
+    markStaticReadIfSymbol(cond);
+    markStaticReadIfSymbol(trueExpression);
+    markStaticReadIfSymbol(falseExpression);
+    node->setLine(loc);
+    return expressionOrFoldedResult(node);
+}
+
+//
+// Parse an array of strings using yyparse.
+//
+// Returns 0 for success.
+//
+int PaParseStrings(size_t count,
+                   const char *const string[],
+                   const int length[],
+                   TParseContext *context)
+{
+    if ((count == 0) || (string == nullptr))
+        return 1;
+
+    if (glslang_initialize(context))
+        return 1;
+
+    int error = glslang_scan(count, string, length, context);
+    if (!error)
+        error = glslang_parse(context);
+
+    glslang_finalize(context);
+
+    return (error == 0) && (context->numErrors() == 0) ? 0 : 1;
+}
+
+}  // namespace sh