r278989. Thanks, Hans
On Tue, Aug 16, 2016 at 6:46 PM, Richard Smith <rich...@metafoo.co.uk> wrote: > Looks fine to me. (At one point we were deliberately not following GCC in > making -fwrapv affect left shift, because it's a bit operation rather than > an arithmetic one, but this is ultimately supposed to be a GCC-compatible > flag so behaving as they do seems reasonable.) > > > On Tue, Aug 16, 2016 at 9:38 AM, Aaron Ballman <aa...@aaronballman.com> > wrote: >> >> I'm not Richard, but I agree with merging it into 3.9 nonetheless. :-) >> >> ~Aaron >> >> On Tue, Aug 16, 2016 at 12:30 PM, Hans Wennborg via cfe-commits >> <cfe-commits@lists.llvm.org> wrote: >> > Seems reasonable to me if Richard agrees. >> > >> > On Tue, Aug 16, 2016 at 3:01 AM, James Molloy <ja...@jamesmolloy.co.uk> >> > wrote: >> >> Hi Hans, >> >> >> >> [cc. Richard as code owner] >> >> >> >> I'd like to nominate this commit for 3.9. The actual code churn is >> >> tiny, and >> >> this fixes a problem noticed by and causing pain to the qemu project. >> >> >> >> Cheers, >> >> >> >> James >> >> >> >> On Tue, 16 Aug 2016 at 10:53 James Molloy via cfe-commits >> >> <cfe-commits@lists.llvm.org> wrote: >> >>> >> >>> Author: jamesm >> >>> Date: Tue Aug 16 04:45:36 2016 >> >>> New Revision: 278786 >> >>> >> >>> URL: http://llvm.org/viewvc/llvm-project?rev=278786&view=rev >> >>> Log: >> >>> Left shifts of negative values are defined if -fwrapv is set >> >>> >> >>> This means we shouldn't emit ubsan detection code or warn. >> >>> Fixes PR25552. >> >>> >> >>> Added: >> >>> cfe/trunk/test/CodeGen/wrapv-lshr-sanitize.c >> >>> cfe/trunk/test/Sema/negative-shift-wrapv.c >> >>> Modified: >> >>> cfe/trunk/lib/CodeGen/CGExprScalar.cpp >> >>> cfe/trunk/lib/Sema/SemaExpr.cpp >> >>> >> >>> Modified: cfe/trunk/lib/CodeGen/CGExprScalar.cpp >> >>> URL: >> >>> >> >>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprScalar.cpp?rev=278786&r1=278785&r2=278786&view=diff >> >>> >> >>> >> >>> ============================================================================== >> >>> --- cfe/trunk/lib/CodeGen/CGExprScalar.cpp (original) >> >>> +++ cfe/trunk/lib/CodeGen/CGExprScalar.cpp Tue Aug 16 04:45:36 2016 >> >>> @@ -2714,7 +2714,8 @@ Value *ScalarExprEmitter::EmitShl(const >> >>> RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, >> >>> "sh_prom"); >> >>> >> >>> bool SanitizeBase = CGF.SanOpts.has(SanitizerKind::ShiftBase) && >> >>> - Ops.Ty->hasSignedIntegerRepresentation(); >> >>> + Ops.Ty->hasSignedIntegerRepresentation() && >> >>> + !CGF.getLangOpts().isSignedOverflowDefined(); >> >>> bool SanitizeExponent = >> >>> CGF.SanOpts.has(SanitizerKind::ShiftExponent); >> >>> // OpenCL 6.3j: shift values are effectively % word size of LHS. >> >>> if (CGF.getLangOpts().OpenCL) >> >>> >> >>> Modified: cfe/trunk/lib/Sema/SemaExpr.cpp >> >>> URL: >> >>> >> >>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=278786&r1=278785&r2=278786&view=diff >> >>> >> >>> >> >>> ============================================================================== >> >>> --- cfe/trunk/lib/Sema/SemaExpr.cpp (original) >> >>> +++ cfe/trunk/lib/Sema/SemaExpr.cpp Tue Aug 16 04:45:36 2016 >> >>> @@ -8670,7 +8670,7 @@ static void DiagnoseBadShiftValues(Sema& >> >>> >> >>> // If LHS does not have a signed type and non-negative value >> >>> // then, the behavior is undefined. Warn about it. >> >>> - if (Left.isNegative()) { >> >>> + if (Left.isNegative() && >> >>> !S.getLangOpts().isSignedOverflowDefined()) { >> >>> S.DiagRuntimeBehavior(Loc, LHS.get(), >> >>> S.PDiag(diag::warn_shift_lhs_negative) >> >>> << LHS.get()->getSourceRange()); >> >>> >> >>> Added: cfe/trunk/test/CodeGen/wrapv-lshr-sanitize.c >> >>> URL: >> >>> >> >>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/wrapv-lshr-sanitize.c?rev=278786&view=auto >> >>> >> >>> >> >>> ============================================================================== >> >>> --- cfe/trunk/test/CodeGen/wrapv-lshr-sanitize.c (added) >> >>> +++ cfe/trunk/test/CodeGen/wrapv-lshr-sanitize.c Tue Aug 16 04:45:36 >> >>> 2016 >> >>> @@ -0,0 +1,12 @@ >> >>> +// RUN: %clang_cc1 -fsanitize=shift-base -emit-llvm %s -o - -triple >> >>> x86_64-linux-gnu -fwrapv | FileCheck %s >> >>> + >> >>> +// CHECK-LABEL: @lsh_overflow >> >>> +int lsh_overflow(int a, int b) { >> >>> + // CHECK-NOT: br >> >>> + // CHECK-NOT: call void @__ubsan_ >> >>> + // CHECK-NOT: call void @llvm.trap >> >>> + >> >>> + // CHECK: %[[RET:.*]] = shl i32 >> >>> + // CHECK-NEXT: ret i32 %[[RET]] >> >>> + return a << b; >> >>> +} >> >>> >> >>> Added: cfe/trunk/test/Sema/negative-shift-wrapv.c >> >>> URL: >> >>> >> >>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/negative-shift-wrapv.c?rev=278786&view=auto >> >>> >> >>> >> >>> ============================================================================== >> >>> --- cfe/trunk/test/Sema/negative-shift-wrapv.c (added) >> >>> +++ cfe/trunk/test/Sema/negative-shift-wrapv.c Tue Aug 16 04:45:36 >> >>> 2016 >> >>> @@ -0,0 +1,9 @@ >> >>> +// RUN: %clang_cc1 -Wall -ffreestanding -fsyntax-only -fwrapv -verify >> >>> %s >> >>> + >> >>> +int test() { >> >>> + int i; >> >>> + i = -1 << 1; // no-warning >> >>> + return i; >> >>> +} >> >>> + >> >>> +// expected-no-diagnostics >> >>> >> >>> >> >>> _______________________________________________ >> >>> cfe-commits mailing list >> >>> cfe-commits@lists.llvm.org >> >>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >> > _______________________________________________ >> > cfe-commits mailing list >> > cfe-commits@lists.llvm.org >> > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits > > _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
