kc3-lang/angle/src/compiler/translator/tree_ops/gl/RegenerateStructNames.cpp

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• Author : Shahbaz Youssefi
  Date : 2021-01-06 14:13:29
  Hash : 5e280545
  Message : Move RegenerateStructNames AST transformation to gl/ This AST transformation is used by the chromium validating command decoder on Linux/AMD/GL as well as MacOS. Bug: chromium:1161513 Change-Id: I67e40215ae5576819ba5a58987ceb1776c86c731 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2613195 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Yuly Novikov <ynovikov@chromium.org>

• src/compiler/translator/tree_ops/gl/RegenerateStructNames.cpp

• //
  // 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