Example #1
0
/// 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;
}
Example #2
0
/// 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
    // mode on function-type macros.
    if (IsFunctionTypeMacro)
      PP.Diag(beginLoc, diag::warn_defined_in_function_type_macro);
    else
      PP.Diag(beginLoc, diag::warn_defined_in_object_type_macro);
  }

  // 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;
}