1 files changed, 119 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/tree_ops/gl/RegenerateStructNames.cpp b/gfx/angle/checkout/src/compiler/translator/tree_ops/gl/RegenerateStructNames.cpp
new file mode 100644
index 0000000000..e15ef32166
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/tree_ops/gl/RegenerateStructNames.cpp
@@ -0,0 +1,119 @@
+//
+// 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/tree_ops/gl/RegenerateStructNames.h"
+
+#include "common/debug.h"
+#include "compiler/translator/Compiler.h"
+#include "compiler/translator/ImmutableStringBuilder.h"
+#include "compiler/translator/SymbolTable.h"
+#include "compiler/translator/tree_util/IntermTraverse.h"
+
+#include <set>
+
+namespace sh
+{
+
+namespace
+{
+constexpr const ImmutableString kPrefix("_webgl_struct_");
+}  // anonymous namespace
+
+class RegenerateStructNamesTraverser : public TIntermTraverser
+{
+  public:
+    RegenerateStructNamesTraverser(TSymbolTable *symbolTable)
+        : TIntermTraverser(true, false, false, symbolTable), mScopeDepth(0)
+    {}
+
+  protected:
+    void visitSymbol(TIntermSymbol *) override;
+    bool visitBlock(Visit, TIntermBlock *block) override;
+
+  private:
+    // Indicating the depth of the current scope.
+    // The global scope is 1.
+    int mScopeDepth;
+
+    // If a struct is declared globally, push its ID in this set.
+    std::set<int> mDeclaredGlobalStructs;
+};
+
+void RegenerateStructNamesTraverser::visitSymbol(TIntermSymbol *symbol)
+{
+    ASSERT(symbol);
+    const TType &type          = symbol->getType();
+    const TStructure *userType = type.getStruct();
+    if (!userType)
+        return;
+
+    if (userType->symbolType() == SymbolType::BuiltIn ||
+        userType->symbolType() == SymbolType::Empty)
+    {
+        // Built-in struct or nameless struct, do not touch it.
+        return;
+    }
+
+    int uniqueId = userType->uniqueId().get();
+
+    ASSERT(mScopeDepth > 0);
+    if (mScopeDepth == 1)
+    {
+        // If a struct is defined at global scope, we don't map its name.
+        // This is because at global level, the struct might be used to
+        // declare a uniform, so the same name needs to stay the same for
+        // vertex/fragment shaders. However, our mapping uses internal ID,
+        // which will be different for the same struct in vertex/fragment
+        // shaders.
+        // This is OK because names for any structs defined in other scopes
+        // will begin with "_webgl", which is reserved. So there will be
+        // no conflicts among unmapped struct names from global scope and
+        // mapped struct names from other scopes.
+        // However, we need to keep track of these global structs, so if a
+        // variable is used in a local scope, we don't try to modify the
+        // struct name through that variable.
+        mDeclaredGlobalStructs.insert(uniqueId);
+        return;
+    }
+    if (mDeclaredGlobalStructs.count(uniqueId) > 0)
+        return;
+    // Map {name} to _webgl_struct_{uniqueId}_{name}.
+    if (userType->name().beginsWith(kPrefix))
+    {
+        // The name has already been regenerated.
+        return;
+    }
+    ImmutableStringBuilder tmp(kPrefix.length() + sizeof(uniqueId) * 2u + 1u +
+                               userType->name().length());
+    tmp << kPrefix;
+    tmp.appendHex(uniqueId);
+    tmp << '_' << userType->name();
+
+    // TODO(oetuaho): Add another mechanism to change symbol names so that the const_cast is not
+    // needed.
+    const_cast<TStructure *>(userType)->setName(tmp);
+}
+
+bool RegenerateStructNamesTraverser::visitBlock(Visit, TIntermBlock *block)
+{
+    ++mScopeDepth;
+    TIntermSequence &sequence = *(block->getSequence());
+    for (TIntermNode *node : sequence)
+    {
+        node->traverse(this);
+    }
+    --mScopeDepth;
+    return false;
+}
+
+bool RegenerateStructNames(TCompiler *compiler, TIntermBlock *root, TSymbolTable *symbolTable)
+{
+    RegenerateStructNamesTraverser traverser(symbolTable);
+    root->traverse(&traverser);
+    return compiler->validateAST(root);
+}
+
+}  // namespace sh