C++ MacroDefinition::forAllDefinitions方法代码示例

void PreprocessingRecord::MacroUndefined(const Token &Id,
                                         const MacroDefinition &MD,
                                         const MacroDirective *Undef) {
  MD.forAllDefinitions([&](MacroInfo *MI) { MacroDefinitions.erase(MI); });
}

/// HandleMacroExpandedIdentifier - If an identifier token is read that is to be
/// expanded as a macro, handle it and return the next token as 'Identifier'.
bool Preprocessor::HandleMacroExpandedIdentifier(Token &Identifier,
                                                 const MacroDefinition &M) {
  MacroInfo *MI = M.getMacroInfo();

  // If this is a macro expansion in the "#if !defined(x)" line for the file,
  // then the macro could expand to different things in other contexts, we need
  // to disable the optimization in this case.
  if (CurPPLexer) CurPPLexer->MIOpt.ExpandedMacro();

  // If this is a builtin macro, like __LINE__ or _Pragma, handle it specially.
  if (MI->isBuiltinMacro()) {
    ExpandBuiltinMacro(Identifier);
    return true;
  }

  /// Args - If this is a function-like macro expansion, this contains,
  /// for each macro argument, the list of tokens that were provided to the
  /// invocation.
  MacroArgs *Args = nullptr;

  // Remember where the end of the expansion occurred.  For an object-like
  // macro, this is the identifier.  For a function-like macro, this is the ')'.
  SourceLocation ExpansionEnd = Identifier.getLocation();

  // If this is a function-like macro, read the arguments.
  if (MI->isFunctionLike()) {
    // Remember that we are now parsing the arguments to a macro invocation.
    // Preprocessor directives used inside macro arguments are not portable, and
    // this enables the warning.
    InMacroArgs = true;
    Args = ReadMacroCallArgumentList(Identifier, MI, ExpansionEnd);

    // Finished parsing args.
    InMacroArgs = false;

    // If there was an error parsing the arguments, bail out.
    if (!Args) return true;

    ++NumFnMacroExpanded;
  } else {
    ++NumMacroExpanded;
  }

  // Notice that this macro has been used.
  markMacroAsUsed(MI);

  // Remember where the token is expanded.
  SourceLocation ExpandLoc = Identifier.getLocation();
  SourceRange ExpansionRange(ExpandLoc, ExpansionEnd);


  // If the macro definition is ambiguous, complain.
  if (M.isAmbiguous()) {
    Diag(Identifier, diag::warn_pp_ambiguous_macro)
      << Identifier.getIdentifierInfo();
    Diag(MI->getDefinitionLoc(), diag::note_pp_ambiguous_macro_chosen)
      << Identifier.getIdentifierInfo();
    M.forAllDefinitions([&](const MacroInfo *OtherMI) {
      if (OtherMI != MI)
        Diag(OtherMI->getDefinitionLoc(), diag::note_pp_ambiguous_macro_other)
          << Identifier.getIdentifierInfo();
    });
  }

  // If we started lexing a macro, enter the macro expansion body.

  // If this macro expands to no tokens, don't bother to push it onto the
  // expansion stack, only to take it right back off.
  if (MI->getNumTokens() == 0) {
    // No need for arg info.
    if (Args) Args->destroy(*this);

    // Propagate whitespace info as if we had pushed, then popped,
    // a macro context.
    Identifier.setFlag(Token::LeadingEmptyMacro);
    PropagateLineStartLeadingSpaceInfo(Identifier);
    ++NumFastMacroExpanded;
    return false;
  } else if (MI->getNumTokens() == 1 &&
             isTrivialSingleTokenExpansion(MI, Identifier.getIdentifierInfo(),
                                           *this)) {
    // Otherwise, if this macro expands into a single trivially-expanded
    // token: expand it now.  This handles common cases like
    // "#define VAL 42".

    // No need for arg info.
    if (Args) Args->destroy(*this);

    // Propagate the isAtStartOfLine/hasLeadingSpace markers of the macro
    // identifier to the expanded token.
    bool isAtStartOfLine = Identifier.isAtStartOfLine();
    bool hasLeadingSpace = Identifier.hasLeadingSpace();

    // Replace the result token.
    Identifier = MI->getReplacementToken(0);

    // Restore the StartOfLine/LeadingSpace markers.
    Identifier.setFlagValue(Token::StartOfLine , isAtStartOfLine);
//.........这里部分代码省略.........