/// 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 // 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; }