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

void PreprocessingRecord::Ifndef(SourceLocation Loc, const Token &MacroNameTok,
                                 const MacroDefinition &MD) {
  // This is not actually a macro expansion but record it as a macro reference.
  if (MD)
    addMacroExpansion(MacroNameTok, MD.getMacroInfo(),
                      MacroNameTok.getLocation());
}

void MacroRepeatedPPCallbacks::MacroExpands(const Token &MacroNameTok,
                                            const MacroDefinition &MD,
                                            SourceRange Range,
                                            const MacroArgs *Args) {
  // Ignore macro argument expansions.
  if (!Range.getBegin().isFileID())
    return;

  const MacroInfo *MI = MD.getMacroInfo();

  // Bail out if the contents of the macro are containing keywords that are
  // making the macro too complex.
  if (std::find_if(
          MI->tokens().begin(), MI->tokens().end(), [](const Token &T) {
            return T.isOneOf(tok::kw_if, tok::kw_else, tok::kw_switch,
                             tok::kw_case, tok::kw_break, tok::kw_while,
                             tok::kw_do, tok::kw_for, tok::kw_continue,
                             tok::kw_goto, tok::kw_return);
          }) != MI->tokens().end())
    return;

  for (unsigned ArgNo = 0U; ArgNo < MI->getNumArgs(); ++ArgNo) {
    const IdentifierInfo *Arg = *(MI->arg_begin() + ArgNo);
    const Token *ResultArgToks = Args->getUnexpArgument(ArgNo);

    if (hasSideEffects(ResultArgToks) &&
        countArgumentExpansions(MI, Arg) >= 2) {
      Check.diag(ResultArgToks->getLocation(),
                 "side effects in the %ordinal0 macro argument '%1' are "
                 "repeated in macro expansion")
          << (ArgNo + 1) << Arg->getName();
      Check.diag(MI->getDefinitionLoc(), "macro %0 defined here",
                 DiagnosticIDs::Note)
          << MacroNameTok.getIdentifierInfo();
    }
  }
}

void PreprocessingRecord::MacroExpands(const Token &Id,
                                       const MacroDefinition &MD,
                                       SourceRange Range,
                                       const MacroArgs *Args) {
  addMacroExpansion(Id, MD.getMacroInfo(), Range);
}

/// EvaluateDefined - Process a 'defined(sym)' expression.
static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
                            bool ValueLive, Preprocessor &PP) {
  SourceLocation beginLoc(PeekTok.getLocation());
  Result.setBegin(beginLoc);

  // Get the next token, don't expand it.
  PP.LexUnexpandedNonComment(PeekTok);

  // Two options, it can either be a pp-identifier or a (.
  SourceLocation LParenLoc;
  if (PeekTok.is(tok::l_paren)) {
    // Found a paren, remember we saw it and skip it.
    LParenLoc = PeekTok.getLocation();
    PP.LexUnexpandedNonComment(PeekTok);
  }

  if (PeekTok.is(tok::code_completion)) {
    if (PP.getCodeCompletionHandler())
      PP.getCodeCompletionHandler()->CodeCompleteMacroName(false);
    PP.setCodeCompletionReached();
    PP.LexUnexpandedNonComment(PeekTok);
  }

  // If we don't have a pp-identifier now, this is an error.
  if (PP.CheckMacroName(PeekTok, MU_Other))
    return true;

  // Otherwise, we got an identifier, is it defined to something?
  IdentifierInfo *II = PeekTok.getIdentifierInfo();
  MacroDefinition Macro = PP.getMacroDefinition(II);
  Result.Val = !!Macro;
  Result.Val.setIsUnsigned(false); // Result is signed intmax_t.

  // If there is a macro, mark it used.
  if (Result.Val != 0 && ValueLive)
    PP.markMacroAsUsed(Macro.getMacroInfo());

  // Save macro token for callback.
  Token macroToken(PeekTok);

  // If we are in parens, ensure we have a trailing ).
  if (LParenLoc.isValid()) {
    // Consume identifier.
    Result.setEnd(PeekTok.getLocation());
    PP.LexUnexpandedNonComment(PeekTok);

    if (PeekTok.isNot(tok::r_paren)) {
      PP.Diag(PeekTok.getLocation(), diag::err_pp_expected_after)
          << "'defined'" << tok::r_paren;
      PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren;
      return true;
    }
    // Consume the ).
    Result.setEnd(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
  } else {
    // Consume identifier.
    Result.setEnd(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
  }

  // Invoke the 'defined' callback.
  if (PPCallbacks *Callbacks = PP.getPPCallbacks()) {
    Callbacks->Defined(macroToken, Macro,
                       SourceRange(beginLoc, PeekTok.getLocation()));
  }

  // Success, remember that we saw defined(X).
  DT.State = DefinedTracker::DefinedMacro;
  DT.TheMacro = II;
  return false;
}

/// EvaluateDefined - Process a 'defined(sym)' expression.
static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
                            bool ValueLive, Preprocessor &PP) {
  SourceLocation beginLoc(PeekTok.getLocation());
  Result.setBegin(beginLoc);

  // Get the next token, don't expand it.
  PP.LexUnexpandedNonComment(PeekTok);

  // Two options, it can either be a pp-identifier or a (.
  SourceLocation LParenLoc;
  if (PeekTok.is(tok::l_paren)) {
    // Found a paren, remember we saw it and skip it.
    LParenLoc = PeekTok.getLocation();
    PP.LexUnexpandedNonComment(PeekTok);
  }

  if (PeekTok.is(tok::code_completion)) {
    if (PP.getCodeCompletionHandler())
      PP.getCodeCompletionHandler()->CodeCompleteMacroName(false);
    PP.setCodeCompletionReached();
    PP.LexUnexpandedNonComment(PeekTok);
  }

  // If we don't have a pp-identifier now, this is an error.
  if (PP.CheckMacroName(PeekTok, MU_Other))
    return true;

  // Otherwise, we got an identifier, is it defined to something?
  IdentifierInfo *II = PeekTok.getIdentifierInfo();
  MacroDefinition Macro = PP.getMacroDefinition(II);
  Result.Val = !!Macro;
  Result.Val.setIsUnsigned(false); // Result is signed intmax_t.

  // If there is a macro, mark it used.
  if (Result.Val != 0 && ValueLive)
    PP.markMacroAsUsed(Macro.getMacroInfo());

  // Save macro token for callback.
  Token macroToken(PeekTok);

  // If we are in parens, ensure we have a trailing ).
  if (LParenLoc.isValid()) {
    // Consume identifier.
    Result.setEnd(PeekTok.getLocation());
    PP.LexUnexpandedNonComment(PeekTok);

    if (PeekTok.isNot(tok::r_paren)) {
      PP.Diag(PeekTok.getLocation(), diag::err_pp_expected_after)
          << "'defined'" << tok::r_paren;
      PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren;
      return true;
    }
    // Consume the ).
    Result.setEnd(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
  } else {
    // Consume identifier.
    Result.setEnd(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
  }

  // [cpp.cond]p4:
  //   Prior to evaluation, macro invocations in the list of preprocessing
  //   tokens that will become the controlling constant expression are replaced
  //   (except for those macro names modified by the 'defined' unary operator),
  //   just as in normal text. If the token 'defined' is generated as a result
  //   of this replacement process or use of the 'defined' unary operator does
  //   not match one of the two specified forms prior to macro replacement, the
  //   behavior is undefined.
  // This isn't an idle threat, consider this program:
  //   #define FOO
  //   #define BAR defined(FOO)
  //   #if BAR
  //   ...
  //   #else
  //   ...
  //   #endif
  // clang and gcc will pick the #if branch while Visual Studio will take the
  // #else branch.  Emit a warning about this undefined behavior.
  if (beginLoc.isMacroID()) {
    bool IsFunctionTypeMacro =
        PP.getSourceManager()
            .getSLocEntry(PP.getSourceManager().getFileID(beginLoc))
            .getExpansion()
            .isFunctionMacroExpansion();
    // For object-type macros, it's easy to replace
    //   #define FOO defined(BAR)
    // with
    //   #if defined(BAR)
    //   #define FOO 1
    //   #else
    //   #define FOO 0
    //   #endif
    // and doing so makes sense since compilers handle this differently in
    // practice (see example further up).  But for function-type macros,
    // there is no good way to write
    //   # define FOO(x) (defined(M_ ## x) && M_ ## x)
    // in a different way, and compilers seem to agree on how to behave here.
    // So warn by default on object-type macros, but only warn in -pedantic
//.........这里部分代码省略.........

/// 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.........