1 files changed, 315 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/ValidateSwitch.cpp b/gfx/angle/checkout/src/compiler/translator/ValidateSwitch.cpp
new file mode 100644
index 0000000000..8a9e7b22a1
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/ValidateSwitch.cpp
@@ -0,0 +1,315 @@
+//
+// 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/ValidateSwitch.h"
+
+#include "compiler/translator/Diagnostics.h"
+#include "compiler/translator/tree_util/IntermTraverse.h"
+
+namespace sh
+{
+
+namespace
+{
+
+const int kMaxAllowedTraversalDepth = 256;
+
+class ValidateSwitch : public TIntermTraverser
+{
+  public:
+    static bool validate(TBasicType switchType,
+                         TDiagnostics *diagnostics,
+                         TIntermBlock *statementList,
+                         const TSourceLoc &loc);
+
+    void visitSymbol(TIntermSymbol *) override;
+    void visitConstantUnion(TIntermConstantUnion *) override;
+    bool visitDeclaration(Visit, TIntermDeclaration *) override;
+    bool visitBlock(Visit visit, TIntermBlock *) override;
+    bool visitBinary(Visit, TIntermBinary *) override;
+    bool visitUnary(Visit, TIntermUnary *) override;
+    bool visitTernary(Visit, TIntermTernary *) override;
+    bool visitSwizzle(Visit, TIntermSwizzle *) override;
+    bool visitIfElse(Visit visit, TIntermIfElse *) override;
+    bool visitSwitch(Visit, TIntermSwitch *) override;
+    bool visitCase(Visit, TIntermCase *node) override;
+    bool visitAggregate(Visit, TIntermAggregate *) override;
+    bool visitLoop(Visit visit, TIntermLoop *) override;
+    bool visitBranch(Visit, TIntermBranch *) override;
+
+  private:
+    ValidateSwitch(TBasicType switchType, TDiagnostics *context);
+
+    bool validateInternal(const TSourceLoc &loc);
+
+    TBasicType mSwitchType;
+    TDiagnostics *mDiagnostics;
+    bool mCaseTypeMismatch;
+    bool mFirstCaseFound;
+    bool mStatementBeforeCase;
+    bool mLastStatementWasCase;
+    int mControlFlowDepth;
+    bool mCaseInsideControlFlow;
+    int mDefaultCount;
+    std::set<int> mCasesSigned;
+    std::set<unsigned int> mCasesUnsigned;
+    bool mDuplicateCases;
+};
+
+bool ValidateSwitch::validate(TBasicType switchType,
+                              TDiagnostics *diagnostics,
+                              TIntermBlock *statementList,
+                              const TSourceLoc &loc)
+{
+    ValidateSwitch validate(switchType, diagnostics);
+    ASSERT(statementList);
+    statementList->traverse(&validate);
+    return validate.validateInternal(loc);
+}
+
+ValidateSwitch::ValidateSwitch(TBasicType switchType, TDiagnostics *diagnostics)
+    : TIntermTraverser(true, false, true, nullptr),
+      mSwitchType(switchType),
+      mDiagnostics(diagnostics),
+      mCaseTypeMismatch(false),
+      mFirstCaseFound(false),
+      mStatementBeforeCase(false),
+      mLastStatementWasCase(false),
+      mControlFlowDepth(0),
+      mCaseInsideControlFlow(false),
+      mDefaultCount(0),
+      mDuplicateCases(false)
+{
+    setMaxAllowedDepth(kMaxAllowedTraversalDepth);
+}
+
+void ValidateSwitch::visitSymbol(TIntermSymbol *)
+{
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+}
+
+void ValidateSwitch::visitConstantUnion(TIntermConstantUnion *)
+{
+    // Conditions of case labels are not traversed, so this is some other constant
+    // Could be just a statement like "0;"
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+}
+
+bool ValidateSwitch::visitDeclaration(Visit, TIntermDeclaration *)
+{
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    return true;
+}
+
+bool ValidateSwitch::visitBlock(Visit visit, TIntermBlock *)
+{
+    if (getParentNode() != nullptr)
+    {
+        if (!mFirstCaseFound)
+            mStatementBeforeCase = true;
+        mLastStatementWasCase = false;
+        if (visit == PreVisit)
+            ++mControlFlowDepth;
+        if (visit == PostVisit)
+            --mControlFlowDepth;
+    }
+    return true;
+}
+
+bool ValidateSwitch::visitBinary(Visit, TIntermBinary *)
+{
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    return true;
+}
+
+bool ValidateSwitch::visitUnary(Visit, TIntermUnary *)
+{
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    return true;
+}
+
+bool ValidateSwitch::visitTernary(Visit, TIntermTernary *)
+{
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    return true;
+}
+
+bool ValidateSwitch::visitSwizzle(Visit, TIntermSwizzle *)
+{
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    return true;
+}
+
+bool ValidateSwitch::visitIfElse(Visit visit, TIntermIfElse *)
+{
+    if (visit == PreVisit)
+        ++mControlFlowDepth;
+    if (visit == PostVisit)
+        --mControlFlowDepth;
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    return true;
+}
+
+bool ValidateSwitch::visitSwitch(Visit, TIntermSwitch *)
+{
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    // Don't go into nested switch statements
+    return false;
+}
+
+bool ValidateSwitch::visitCase(Visit, TIntermCase *node)
+{
+    const char *nodeStr = node->hasCondition() ? "case" : "default";
+    if (mControlFlowDepth > 0)
+    {
+        mDiagnostics->error(node->getLine(), "label statement nested inside control flow", nodeStr);
+        mCaseInsideControlFlow = true;
+    }
+    mFirstCaseFound       = true;
+    mLastStatementWasCase = true;
+    if (!node->hasCondition())
+    {
+        ++mDefaultCount;
+        if (mDefaultCount > 1)
+        {
+            mDiagnostics->error(node->getLine(), "duplicate default label", nodeStr);
+        }
+    }
+    else
+    {
+        TIntermConstantUnion *condition = node->getCondition()->getAsConstantUnion();
+        if (condition == nullptr)
+        {
+            // This can happen in error cases.
+            return false;
+        }
+        TBasicType conditionType = condition->getBasicType();
+        if (conditionType != mSwitchType)
+        {
+            mDiagnostics->error(condition->getLine(),
+                                "case label type does not match switch init-expression type",
+                                nodeStr);
+            mCaseTypeMismatch = true;
+        }
+
+        if (conditionType == EbtInt)
+        {
+            int iConst = condition->getIConst(0);
+            if (mCasesSigned.find(iConst) != mCasesSigned.end())
+            {
+                mDiagnostics->error(condition->getLine(), "duplicate case label", nodeStr);
+                mDuplicateCases = true;
+            }
+            else
+            {
+                mCasesSigned.insert(iConst);
+            }
+        }
+        else if (conditionType == EbtUInt)
+        {
+            unsigned int uConst = condition->getUConst(0);
+            if (mCasesUnsigned.find(uConst) != mCasesUnsigned.end())
+            {
+                mDiagnostics->error(condition->getLine(), "duplicate case label", nodeStr);
+                mDuplicateCases = true;
+            }
+            else
+            {
+                mCasesUnsigned.insert(uConst);
+            }
+        }
+        // Other types are possible only in error cases, where the error has already been generated
+        // when parsing the case statement.
+    }
+    // Don't traverse the condition of the case statement
+    return false;
+}
+
+bool ValidateSwitch::visitAggregate(Visit visit, TIntermAggregate *)
+{
+    if (getParentNode() != nullptr)
+    {
+        // This is not the statementList node, but some other node.
+        if (!mFirstCaseFound)
+            mStatementBeforeCase = true;
+        mLastStatementWasCase = false;
+    }
+    return true;
+}
+
+bool ValidateSwitch::visitLoop(Visit visit, TIntermLoop *)
+{
+    if (visit == PreVisit)
+        ++mControlFlowDepth;
+    if (visit == PostVisit)
+        --mControlFlowDepth;
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    return true;
+}
+
+bool ValidateSwitch::visitBranch(Visit, TIntermBranch *)
+{
+    if (!mFirstCaseFound)
+        mStatementBeforeCase = true;
+    mLastStatementWasCase = false;
+    return true;
+}
+
+bool ValidateSwitch::validateInternal(const TSourceLoc &loc)
+{
+    if (mStatementBeforeCase)
+    {
+        mDiagnostics->error(loc, "statement before the first label", "switch");
+    }
+    if (mLastStatementWasCase)
+    {
+        // There have been some differences between versions of GLSL ES specs on whether this should
+        // be an error or not, but as of early 2018 the latest discussion is that this is an error
+        // also on GLSL ES versions newer than 3.00.
+        mDiagnostics->error(
+            loc, "no statement between the last label and the end of the switch statement",
+            "switch");
+    }
+    if (getMaxDepth() >= kMaxAllowedTraversalDepth)
+    {
+        mDiagnostics->error(loc, "too complex expressions inside a switch statement", "switch");
+    }
+    return !mStatementBeforeCase && !mLastStatementWasCase && !mCaseInsideControlFlow &&
+           !mCaseTypeMismatch && mDefaultCount <= 1 && !mDuplicateCases &&
+           getMaxDepth() < kMaxAllowedTraversalDepth;
+}
+
+}  // anonymous namespace
+
+bool ValidateSwitchStatementList(TBasicType switchType,
+                                 TDiagnostics *diagnostics,
+                                 TIntermBlock *statementList,
+                                 const TSourceLoc &loc)
+{
+    return ValidateSwitch::validate(switchType, diagnostics, statementList, loc);
+}
+
+}  // namespace sh