Author: danielmarjamaki Date: Thu Sep 22 09:13:46 2016 New Revision: 282156
URL: http://llvm.org/viewvc/llvm-project?rev=282156&view=rev Log: Fix Wbitfield-constant-conversion false positives Summary: The diagnostic did not handle ~ well. An expression such as ~0 is often used when 'all ones' is needed. Differential Revision: https://reviews.llvm.org/D24232 Modified: cfe/trunk/lib/Sema/SemaChecking.cpp cfe/trunk/test/Sema/constant-conversion.c Modified: cfe/trunk/lib/Sema/SemaChecking.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=282156&r1=282155&r2=282156&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaChecking.cpp (original) +++ cfe/trunk/lib/Sema/SemaChecking.cpp Thu Sep 22 09:13:46 2016 @@ -8006,11 +8006,10 @@ bool AnalyzeBitFieldAssignment(Sema &S, unsigned OriginalWidth = Value.getBitWidth(); unsigned FieldWidth = Bitfield->getBitWidthValue(S.Context); - if (Value.isSigned() && Value.isNegative()) + if (!Value.isSigned() || Value.isNegative()) if (UnaryOperator *UO = dyn_cast<UnaryOperator>(OriginalInit)) - if (UO->getOpcode() == UO_Minus) - if (isa<IntegerLiteral>(UO->getSubExpr())) - OriginalWidth = Value.getMinSignedBits(); + if (UO->getOpcode() == UO_Minus || UO->getOpcode() == UO_Not) + OriginalWidth = Value.getMinSignedBits(); if (OriginalWidth <= FieldWidth) return false; Modified: cfe/trunk/test/Sema/constant-conversion.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/constant-conversion.c?rev=282156&r1=282155&r2=282156&view=diff ============================================================================== --- cfe/trunk/test/Sema/constant-conversion.c (original) +++ cfe/trunk/test/Sema/constant-conversion.c Thu Sep 22 09:13:46 2016 @@ -69,7 +69,8 @@ void test7() { unsigned int reserved:28; } f; - f.twoBits1 = ~1; // expected-warning {{implicit truncation from 'int' to bitfield changes value from -2 to 2}} + f.twoBits1 = ~0; // no-warning + f.twoBits1 = ~1; // no-warning f.twoBits2 = ~2; // expected-warning {{implicit truncation from 'int' to bitfield changes value from -3 to 1}} f.twoBits1 &= ~1; // no-warning f.twoBits2 &= ~2; // no-warning @@ -114,6 +115,8 @@ void test9() { char array_init[] = { 255, 127, 128, 129, 0 }; } +#define A 1 + void test10() { struct S { unsigned a : 4; @@ -121,7 +124,10 @@ void test10() { s.a = -1; s.a = 15; s.a = -8; + s.a = ~0; + s.a = ~0U; + s.a = ~(1<<A); - s.a = -9; // expected-warning{{implicit truncation from 'int' to bitfield changes value from -9 to 7}} +s.a = -9; // expected-warning{{implicit truncation from 'int' to bitfield changes value from -9 to 7}} s.a = 16; // expected-warning{{implicit truncation from 'int' to bitfield changes value from 16 to 0}} } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
