chromium/third_party/angle/src/compiler/translator/tree_ops/DeferGlobalInitializers.cpp

//
// Copyright 2016 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.
//
// DeferGlobalInitializers is an AST traverser that moves global initializers into a separate
// function that is called in the beginning of main(). This enables initialization of globals with
// uniforms or non-constant globals, as allowed by the WebGL spec. Some initializers referencing
// non-constants may need to be unfolded into if statements in HLSL - this kind of steps should be
// done after DeferGlobalInitializers is run. Note that it's important that the function definition
// is at the end of the shader, as some globals may be declared after main().
//
// It can also initialize all uninitialized globals.
//

#include "compiler/translator/tree_ops/DeferGlobalInitializers.h"

#include <vector>

#include "compiler/translator/Compiler.h"
#include "compiler/translator/IntermNode.h"
#include "compiler/translator/StaticType.h"
#include "compiler/translator/SymbolTable.h"
#include "compiler/translator/tree_ops/InitializeVariables.h"
#include "compiler/translator/tree_util/FindMain.h"
#include "compiler/translator/tree_util/IntermNode_util.h"
#include "compiler/translator/tree_util/ReplaceVariable.h"

namespace sh
{

namespace
{

constexpr const ImmutableString kInitGlobalsString("initGlobals");

void GetDeferredInitializers(TIntermDeclaration *declaration,
                             bool initializeUninitializedGlobals,
                             bool canUseLoopsToInitialize,
                             bool highPrecisionSupported,
                             bool forceDeferNonConstGlobalInitializers,
                             TIntermSequence *deferredInitializersOut,
                             std::vector<const TVariable *> *variablesToReplaceOut,
                             TSymbolTable *symbolTable)
{ … }

void InsertInitCallToMain(TIntermBlock *root,
                          TIntermSequence *deferredInitializers,
                          TSymbolTable *symbolTable)
{ … }

}  // namespace

bool DeferGlobalInitializers(TCompiler *compiler,
                             TIntermBlock *root,
                             bool initializeUninitializedGlobals,
                             bool canUseLoopsToInitialize,
                             bool highPrecisionSupported,
                             bool forceDeferNonConstGlobalInitializers,
                             TSymbolTable *symbolTable)
{ … }

}  // namespace sh