Author: Richard Smith Date: 2021-01-27T13:34:15-08:00 New Revision: 5dfa37a76153f2a18ac7fe30721cc1332b672ea2
URL: https://github.com/llvm/llvm-project/commit/5dfa37a76153f2a18ac7fe30721cc1332b672ea2 DIFF: https://github.com/llvm/llvm-project/commit/5dfa37a76153f2a18ac7fe30721cc1332b672ea2.diff LOG: Don't allow __VA_OPT__ to be detected by #ifdef. More study has discovered this to not actually be useful: because current C++20 implementations reject `#ifdef __VA_OPT__`, this can't really be used as a feature-test mechanism. And it's not too hard to detect __VA_OPT__ without this, for example: #define THIRD_ARG(a, b, c, ...) c #define HAS_VA_OPT(...) THIRD_ARG(__VA_OPT__(,), 1, 0, ) #if HAS_VA_OPT(?) Partially reverts 0436ec2128c9775ba13b0308937238fc79673fdd. Added: Modified: clang/include/clang/Lex/Preprocessor.h clang/lib/Lex/PPDirectives.cpp clang/lib/Lex/PPExpressions.cpp clang/lib/Lex/PPMacroExpansion.cpp clang/lib/Lex/Preprocessor.cpp clang/test/Preprocessor/macro_vaopt_check.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h index ba8bdaa23c4c..68139cb24b31 100644 --- a/clang/include/clang/Lex/Preprocessor.h +++ b/clang/include/clang/Lex/Preprocessor.h @@ -447,25 +447,6 @@ class Preprocessor { ElseLoc(ElseLoc) {} }; - class IfdefMacroNameScopeRAII { - Preprocessor &PP; - bool VAOPTWasPoisoned; - - public: - IfdefMacroNameScopeRAII(Preprocessor &PP) - : PP(PP), VAOPTWasPoisoned(PP.Ident__VA_OPT__->isPoisoned()) { - PP.Ident__VA_OPT__->setIsPoisoned(false); - } - IfdefMacroNameScopeRAII(const IfdefMacroNameScopeRAII&) = delete; - IfdefMacroNameScopeRAII &operator=(const IfdefMacroNameScopeRAII&) = delete; - ~IfdefMacroNameScopeRAII() { Exit(); } - - void Exit() { - if (VAOPTWasPoisoned) - PP.Ident__VA_OPT__->setIsPoisoned(true); - } - }; - private: friend class ASTReader; friend class MacroArgs; diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp index e2aa93455ea5..d6b03d85913d 100644 --- a/clang/lib/Lex/PPDirectives.cpp +++ b/clang/lib/Lex/PPDirectives.cpp @@ -2928,14 +2928,9 @@ void Preprocessor::HandleIfdefDirective(Token &Result, ++NumIf; Token DirectiveTok = Result; - // __VA_OPT__ is allowed as the operand of #if[n]def. - IfdefMacroNameScopeRAII IfdefMacroNameScope(*this); - Token MacroNameTok; ReadMacroName(MacroNameTok); - IfdefMacroNameScope.Exit(); - // Error reading macro name? If so, diagnostic already issued. if (MacroNameTok.is(tok::eod)) { // Skip code until we get to #endif. This helps with recovery by not diff --git a/clang/lib/Lex/PPExpressions.cpp b/clang/lib/Lex/PPExpressions.cpp index 952fb8f121dc..8c120c13d7d2 100644 --- a/clang/lib/Lex/PPExpressions.cpp +++ b/clang/lib/Lex/PPExpressions.cpp @@ -104,9 +104,6 @@ static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT, SourceLocation beginLoc(PeekTok.getLocation()); Result.setBegin(beginLoc); - // __VA_OPT__ is allowed as the operand of 'defined'. - Preprocessor::IfdefMacroNameScopeRAII IfdefMacroNameScope(PP); - // Get the next token, don't expand it. PP.LexUnexpandedNonComment(PeekTok); @@ -125,8 +122,6 @@ static bool EvaluateDefined(PPValue &Result, Token &PeekTok, DefinedTracker &DT, PP.LexUnexpandedNonComment(PeekTok); } - IfdefMacroNameScope.Exit(); - // If we don't have a pp-identifier now, this is an error. if (PP.CheckMacroName(PeekTok, MU_Other)) return true; diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp index f6ca04defeb9..43d31d6c5732 100644 --- a/clang/lib/Lex/PPMacroExpansion.cpp +++ b/clang/lib/Lex/PPMacroExpansion.cpp @@ -323,16 +323,13 @@ void Preprocessor::dumpMacroInfo(const IdentifierInfo *II) { /// RegisterBuiltinMacro - Register the specified identifier in the identifier /// table and mark it as a builtin macro to be expanded. -static IdentifierInfo *RegisterBuiltinMacro(Preprocessor &PP, const char *Name, - bool Disabled = false) { +static IdentifierInfo *RegisterBuiltinMacro(Preprocessor &PP, const char *Name){ // Get the identifier. IdentifierInfo *Id = PP.getIdentifierInfo(Name); // Mark it as being a macro that is builtin. MacroInfo *MI = PP.AllocateMacroInfo(SourceLocation()); MI->setIsBuiltinMacro(); - if (Disabled) - MI->DisableMacro(); PP.appendDefMacroDirective(Id, MI); return Id; } @@ -346,7 +343,6 @@ void Preprocessor::RegisterBuiltinMacros() { Ident__TIME__ = RegisterBuiltinMacro(*this, "__TIME__"); Ident__COUNTER__ = RegisterBuiltinMacro(*this, "__COUNTER__"); Ident_Pragma = RegisterBuiltinMacro(*this, "_Pragma"); - Ident__VA_OPT__ = RegisterBuiltinMacro(*this, "__VA_OPT__", true); // C++ Standing Document Extensions. if (getLangOpts().CPlusPlus) diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp index 9baba204b324..177786d90390 100644 --- a/clang/lib/Lex/Preprocessor.cpp +++ b/clang/lib/Lex/Preprocessor.cpp @@ -115,20 +115,19 @@ Preprocessor::Preprocessor(std::shared_ptr<PreprocessorOptions> PPOpts, BuiltinInfo = std::make_unique<Builtin::Context>(); + // "Poison" __VA_ARGS__, __VA_OPT__ which can only appear in the expansion of + // a macro. They get unpoisoned where it is allowed. + (Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned(); + SetPoisonReason(Ident__VA_ARGS__,diag::ext_pp_bad_vaargs_use); + (Ident__VA_OPT__ = getIdentifierInfo("__VA_OPT__"))->setIsPoisoned(); + SetPoisonReason(Ident__VA_OPT__,diag::ext_pp_bad_vaopt_use); + // Initialize the pragma handlers. RegisterBuiltinPragmas(); // Initialize builtin macros like __LINE__ and friends. RegisterBuiltinMacros(); - // "Poison" __VA_ARGS__, __VA_OPT__ which can only appear in the expansion of - // a macro. They get unpoisoned where it is allowed. Note that we model - // __VA_OPT__ as a builtin macro to allow #ifdef and friends to detect it. - (Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned(); - SetPoisonReason(Ident__VA_ARGS__, diag::ext_pp_bad_vaargs_use); - Ident__VA_OPT__->setIsPoisoned(); - SetPoisonReason(Ident__VA_OPT__, diag::ext_pp_bad_vaopt_use); - if(LangOpts.Borland) { Ident__exception_info = getIdentifierInfo("_exception_info"); Ident___exception_info = getIdentifierInfo("__exception_info"); diff --git a/clang/test/Preprocessor/macro_vaopt_check.cpp b/clang/test/Preprocessor/macro_vaopt_check.cpp index 84f3b85871dd..c5c0ac518bc0 100644 --- a/clang/test/Preprocessor/macro_vaopt_check.cpp +++ b/clang/test/Preprocessor/macro_vaopt_check.cpp @@ -2,20 +2,6 @@ // RUN: %clang_cc1 %s -Eonly -verify -Wno-all -pedantic -std=c++11 // RUN: %clang_cc1 -x c %s -Eonly -verify -Wno-all -pedantic -std=c99 -// Check that support for __VA_OPT__ can be detected by #ifdef. -#ifndef __VA_OPT__ -#error should be defined -#endif - -#ifdef __VA_OPT__ -#else -#error should be defined -#endif - -#if !defined(__VA_OPT__) -#error should be defined -#endif - //expected-error@+1{{missing '('}} #define V1(...) __VA_OPT__ #undef V1 @@ -82,12 +68,7 @@ #if __VA_OPT__ // expected-warning {{__VA_OPT__ can only appear in the expansion of a variadic macro}} #endif -#define BAD __VA_OPT__ // expected-warning {{__VA_OPT__ can only appear in the expansion of a variadic macro}} - -// Check defined(__VA_OPT__) doesn't leave __VA_OPT__ poisoned. -#define Z(...) (0 __VA_OPT__(|| 1)) -#if defined(__VA_OPT__) && Z(hello) -// OK -#else -#error bad +#ifdef __VA_OPT__ // expected-warning {{__VA_OPT__ can only appear in the expansion of a variadic macro}} #endif + +#define BAD __VA_OPT__ // expected-warning {{__VA_OPT__ can only appear in the expansion of a variadic macro}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
