//
// Copyright 2018 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.
//
// ReplaceVariable.h: Replace all references to a specific variable in the AST with references to
// another variable.

#ifndef COMPILER_TRANSLATOR_TREEUTIL_REPLACEVARIABLE_H_
#define COMPILER_TRANSLATOR_TREEUTIL_REPLACEVARIABLE_H_

#include "common/debug.h"

#include <stack>
#include <unordered_map>

namespace sh
{

class TCompiler;
class TFunction;
class TIntermAggregate;
class TIntermBlock;
class TIntermFunctionPrototype;
class TIntermNode;
class TIntermTyped;
class TSymbolTable;
class TVariable;

ANGLE_NO_DISCARD bool ReplaceVariable(TCompiler *compiler,
                                      TIntermBlock *root,
                                      const TVariable *toBeReplaced,
                                      const TVariable *replacement);
ANGLE_NO_DISCARD bool ReplaceVariableWithTyped(TCompiler *compiler,
                                               TIntermBlock *root,
                                               const TVariable *toBeReplaced,
                                               const TIntermTyped *replacement);

using VariableReplacementMap = angle::HashMap<const TVariable *, const TIntermTyped *>;

// Replace a set of variables with their corresponding expression.
ANGLE_NO_DISCARD bool ReplaceVariables(TCompiler *compiler,
                                       TIntermBlock *root,
                                       const VariableReplacementMap &variableMap);

// Find all declarators, and replace the TVariable they are declaring with a duplicate.  This is
// used to support deepCopy of TIntermBlock and TIntermLoop nodes that include declarations.
// Replacements already present in variableMap are preserved.
void GetDeclaratorReplacements(TSymbolTable *symbolTable,
                               TIntermBlock *root,
                               VariableReplacementMap *variableMap);

}  // namespace sh

#endif  // COMPILER_TRANSLATOR_TREEUTIL_REPLACEVARIABLE_H_