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//
// 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
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