diff -r 000000000000 -r 6474c204b198 gfx/angle/src/compiler/preprocessor/MacroExpander.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/angle/src/compiler/preprocessor/MacroExpander.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,75 @@
+//
+// Copyright (c) 2012 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.
+//
+
+#ifndef COMPILER_PREPROCESSOR_MACRO_EXPANDER_H_
+#define COMPILER_PREPROCESSOR_MACRO_EXPANDER_H_
+
+#include <cassert>
+#include <memory>
+#include <vector>
+
+#include "Lexer.h"
+#include "Macro.h"
+#include "pp_utils.h"
+
+namespace pp
+{
+
+class Diagnostics;
+
+class MacroExpander : public Lexer
+{
+  public:
+    MacroExpander(Lexer* lexer, MacroSet* macroSet, Diagnostics* diagnostics);
+    virtual ~MacroExpander();
+
+    virtual void lex(Token* token);
+
+  private:
+    PP_DISALLOW_COPY_AND_ASSIGN(MacroExpander);
+
+    void getToken(Token* token);
+    void ungetToken(const Token& token);
+    bool isNextTokenLeftParen();
+
+    bool pushMacro(const Macro& macro, const Token& identifier);
+    void popMacro();
+
+    bool expandMacro(const Macro& macro,
+                     const Token& identifier,
+                     std::vector<Token>* replacements);
+
+    typedef std::vector<Token> MacroArg;
+    bool collectMacroArgs(const Macro& macro,
+                          const Token& identifier,
+                          std::vector<MacroArg>* args);
+    void replaceMacroParams(const Macro& macro,
+                            const std::vector<MacroArg>& args,
+                            std::vector<Token>* replacements);
+
+    struct MacroContext
+    {
+        const Macro* macro;
+        std::size_t index;
+        std::vector<Token> replacements;
+
+        MacroContext() : macro(0), index(0) { }
+        bool empty() const { return index == replacements.size(); }
+        const Token& get() { return replacements[index++]; }
+        void unget() { assert(index > 0); --index; }
+    };
+
+    Lexer* mLexer;
+    MacroSet* mMacroSet;
+    Diagnostics* mDiagnostics;
+
+    std::auto_ptr<Token> mReserveToken;
+    std::vector<MacroContext*> mContextStack;
+};
+
+}  // namespace pp
+#endif  // COMPILER_PREPROCESSOR_MACRO_EXPANDER_H_
+