Author: arphaman Date: Wed Feb 7 12:45:39 2018 New Revision: 324514 URL: http://llvm.org/viewvc/llvm-project?rev=324514&view=rev Log: [PR36008] Avoid -Wsign-compare warning for enum constants in typeof expressions
This commit looks through typeof type at the original expression when diagnosing -Wsign-compare to avoid an unfriendly diagnostic. rdar://36588828 Differential Revision: https://reviews.llvm.org/D42561 Modified: cfe/trunk/lib/Sema/SemaChecking.cpp cfe/trunk/test/Sema/compare.c Modified: cfe/trunk/lib/Sema/SemaChecking.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=324514&r1=324513&r2=324514&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaChecking.cpp (original) +++ cfe/trunk/lib/Sema/SemaChecking.cpp Wed Feb 7 12:45:39 2018 @@ -8955,6 +8955,16 @@ static void AnalyzeComparison(Sema &S, B LHS = LHS->IgnoreParenImpCasts(); RHS = RHS->IgnoreParenImpCasts(); + if (!S.getLangOpts().CPlusPlus) { + // Avoid warning about comparison of integers with different signs when + // RHS/LHS has a `typeof(E)` type whose sign is different from the sign of + // the type of `E`. + if (const auto *TET = dyn_cast<TypeOfExprType>(LHS->getType())) + LHS = TET->getUnderlyingExpr()->IgnoreParenImpCasts(); + if (const auto *TET = dyn_cast<TypeOfExprType>(RHS->getType())) + RHS = TET->getUnderlyingExpr()->IgnoreParenImpCasts(); + } + // Check to see if one of the (unmodified) operands is of different // signedness. Expr *signedOperand, *unsignedOperand; Modified: cfe/trunk/test/Sema/compare.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/compare.c?rev=324514&r1=324513&r2=324514&view=diff ============================================================================== --- cfe/trunk/test/Sema/compare.c (original) +++ cfe/trunk/test/Sema/compare.c Wed Feb 7 12:45:39 2018 @@ -391,3 +391,16 @@ typedef char two_chars[2]; void test12(unsigned a) { if (0 && -1 > a) { } } + +// PR36008 + +enum PR36008EnumTest { + kPR36008Value = 0, +}; + +void pr36008(enum PR36008EnumTest lhs) { + __typeof__(lhs) x = lhs; + __typeof__(kPR36008Value) y = (kPR36008Value); + if (x == y) x = y; // no warning + if (y == x) y = x; // no warning +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits