path: root/lib/Lex/PPMacroExpansion.cpp

//===--- MacroExpansion.cpp - Top level Macro Expansion -------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the top level handling of macro expasion for the
// preprocessor.
//
//===----------------------------------------------------------------------===//

#include "clang/Lex/Preprocessor.h"
#include "MacroArgs.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Lex/CodeCompletionHandler.h"
#include "clang/Lex/ExternalPreprocessorSource.h"
#include "clang/Lex/LiteralSupport.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include <cstdio>
#include <ctime>
using namespace clang;

MacroInfo *Preprocessor::getMacroInfoHistory(IdentifierInfo *II) const {
  assert(II->hadMacroDefinition() && "Identifier has not been not a macro!");

  macro_iterator Pos = Macros.find(II);
  if (Pos == Macros.end()) {
    // Load this macro from the external source.
    getExternalSource()->LoadMacroDefinition(II);
    Pos = Macros.find(II);
  }
  assert(Pos != Macros.end() && "Identifier macro info is missing!");
  return Pos->second;
}

/// setMacroInfo - Specify a macro for this identifier.
///
void Preprocessor::setMacroInfo(IdentifierInfo *II, MacroInfo *MI,
                                bool LoadedFromAST) {
  assert(MI && "MacroInfo should be non-zero!");
  assert((LoadedFromAST || MI->getUndefLoc().isInvalid()) &&
         "Undefined macros can only be registered when just LoadedFromAST");
  MI->setPreviousDefinition(Macros[II]);
  Macros[II] = MI;
  II->setHasMacroDefinition(MI->getUndefLoc().isInvalid());
  if (II->isFromAST() && !LoadedFromAST)
    II->setChangedSinceDeserialization();
}

/// \brief Undefine a macro for this identifier.
void Preprocessor::clearMacroInfo(IdentifierInfo *II) {
  assert(II->hasMacroDefinition() && "Macro is not defined!");
  assert(Macros[II]->getUndefLoc().isValid() && "Macro is still defined!");
  II->setHasMacroDefinition(false);
  if (II->isFromAST())
    II->setChangedSinceDeserialization();
}

/// RegisterBuiltinMacro - Register the specified identifier in the identifier
/// table and mark it as a builtin macro to be expanded.
static IdentifierInfo *RegisterBuiltinMacro(Preprocessor &PP, const char *Name){
  // Get the identifier.
  IdentifierInfo *Id = PP.getIdentifierInfo(Name);

  // Mark it as being a macro that is builtin.
  MacroInfo *MI = PP.AllocateMacroInfo(SourceLocation());
  MI->setIsBuiltinMacro();
  PP.setMacroInfo(Id, MI);
  return Id;
}


/// RegisterBuiltinMacros - Register builtin macros, such as __LINE__ with the
/// identifier table.
void Preprocessor::RegisterBuiltinMacros() {
  Ident__LINE__ = RegisterBuiltinMacro(*this, "__LINE__");
  Ident__FILE__ = RegisterBuiltinMacro(*this, "__FILE__");
  Ident__DATE__ = RegisterBuiltinMacro(*this,