C++ (Cpp) Preprocessor::setSkipMainFilePreamble Examples

Example #1

File: InitPreprocessor.cpp Project: meadori/clang

/// InitializePreprocessor - Initialize the preprocessor getting it and the
/// environment ready to process a single file. This returns true on error.
///
void clang::InitializePreprocessor(
    Preprocessor &PP, const PreprocessorOptions &InitOpts,
    const PCHContainerReader &PCHContainerRdr,
    const FrontendOptions &FEOpts) {
  const LangOptions &LangOpts = PP.getLangOpts();
  std::string PredefineBuffer;
  PredefineBuffer.reserve(4080);
  llvm::raw_string_ostream Predefines(PredefineBuffer);
  MacroBuilder Builder(Predefines);

  // Emit line markers for various builtin sections of the file.  We don't do
  // this in asm preprocessor mode, because "# 4" is not a line marker directive
  // in this mode.
  if (!PP.getLangOpts().AsmPreprocessor)
    Builder.append("# 1 \"<built-in>\" 3");

  // Install things like __POWERPC__, __GNUC__, etc into the macro table.
  if (InitOpts.UsePredefines) {
    if (LangOpts.CUDA && PP.getAuxTargetInfo())
      InitializePredefinedMacros(*PP.getAuxTargetInfo(), LangOpts, FEOpts,
                                 Builder);

    InitializePredefinedMacros(PP.getTargetInfo(), LangOpts, FEOpts, Builder);

    // Install definitions to make Objective-C++ ARC work well with various
    // C++ Standard Library implementations.
    if (LangOpts.ObjC1 && LangOpts.CPlusPlus &&
        (LangOpts.ObjCAutoRefCount || LangOpts.ObjCWeak)) {
      switch (InitOpts.ObjCXXARCStandardLibrary) {
      case ARCXX_nolib:
      case ARCXX_libcxx:
        break;

      case ARCXX_libstdcxx:
        AddObjCXXARCLibstdcxxDefines(LangOpts, Builder);
        break;
      }
    }
  }
  
  // Even with predefines off, some macros are still predefined.
  // These should all be defined in the preprocessor according to the
  // current language configuration.
  InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOpts(),
                                     FEOpts, Builder);

  // Add on the predefines from the driver.  Wrap in a #line directive to report
  // that they come from the command line.
  if (!PP.getLangOpts().AsmPreprocessor)
    Builder.append("# 1 \"<command line>\" 1");

  // Process #define's and #undef's in the order they are given.
  for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
    if (InitOpts.Macros[i].second)  // isUndef
      Builder.undefineMacro(InitOpts.Macros[i].first);
    else
      DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
                         PP.getDiagnostics());
  }

  // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
  if (!PP.getLangOpts().AsmPreprocessor)
    Builder.append("# 1 \"<built-in>\" 2");

  // If -imacros are specified, include them now.  These are processed before
  // any -include directives.
  for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
    AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i]);

  // Process -include-pch/-include-pth directives.
  if (!InitOpts.ImplicitPCHInclude.empty())
    AddImplicitIncludePCH(Builder, PP, PCHContainerRdr,
                          InitOpts.ImplicitPCHInclude);
  if (!InitOpts.ImplicitPTHInclude.empty())
    AddImplicitIncludePTH(Builder, PP, InitOpts.ImplicitPTHInclude);

  // Process -include directives.
  for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
    const std::string &Path = InitOpts.Includes[i];
    AddImplicitInclude(Builder, Path);
  }

  // Instruct the preprocessor to skip the preamble.
  PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
                             InitOpts.PrecompiledPreambleBytes.second);
                          
  // Copy PredefinedBuffer into the Preprocessor.
  PP.setPredefines(Predefines.str());
}