[compiler-rt] r337068 - [UBSan] Followup for silence_unsigned_overflow flag to handle negate overflows.
Max Moroz via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 13 15:49:06 PDT 2018
Author: dor1s
Date: Fri Jul 13 15:49:06 2018
New Revision: 337068
URL: http://llvm.org/viewvc/llvm-project?rev=337068&view=rev
Log:
[UBSan] Followup for silence_unsigned_overflow flag to handle negate overflows.
Summary:
That flag has been introduced in https://reviews.llvm.org/D48660 for
suppressing UIO error messages in an efficient way. The main motivation is to
be able to use UIO checks in builds used for fuzzing as it might provide an
interesting signal to a fuzzing engine such as libFuzzer.
See https://github.com/google/oss-fuzz/issues/910 for more information.
Reviewers: morehouse, kcc
Reviewed By: morehouse
Subscribers: kubamracek, delcypher, #sanitizers, llvm-commits
Differential Revision: https://reviews.llvm.org/D49324
Modified:
compiler-rt/trunk/lib/ubsan/ubsan_handlers.cc
compiler-rt/trunk/test/ubsan/TestCases/Integer/negate-overflow.cpp
Modified: compiler-rt/trunk/lib/ubsan/ubsan_handlers.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/ubsan/ubsan_handlers.cc?rev=337068&r1=337067&r2=337068&view=diff
==============================================================================
--- compiler-rt/trunk/lib/ubsan/ubsan_handlers.cc (original)
+++ compiler-rt/trunk/lib/ubsan/ubsan_handlers.cc Fri Jul 13 15:49:06 2018
@@ -156,6 +156,9 @@ static void handleNegateOverflowImpl(Ove
if (ignoreReport(Loc, Opts, ET))
return;
+ if (!IsSigned && flags()->silence_unsigned_overflow)
+ return;
+
ScopedReport R(Opts, Loc, ET);
if (IsSigned)
Modified: compiler-rt/trunk/test/ubsan/TestCases/Integer/negate-overflow.cpp
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/ubsan/TestCases/Integer/negate-overflow.cpp?rev=337068&r1=337067&r2=337068&view=diff
==============================================================================
--- compiler-rt/trunk/test/ubsan/TestCases/Integer/negate-overflow.cpp (original)
+++ compiler-rt/trunk/test/ubsan/TestCases/Integer/negate-overflow.cpp Fri Jul 13 15:49:06 2018
@@ -1,10 +1,12 @@
// RUN: %clangxx -fsanitize=signed-integer-overflow %s -o %t1 && %run %t1 2>&1 | FileCheck %s --check-prefix=CHECKS
// RUN: %clangxx -fsanitize=unsigned-integer-overflow %s -o %t2 && %run %t2 2>&1 | FileCheck %s --check-prefix=CHECKU
+// RUN: %clangxx -fsanitize=unsigned-integer-overflow %s -o %t2 && %env_ubsan_opts=silence_unsigned_overflow=1 %run %t2 2>&1 | FileCheck %s --check-prefix=CHECKU-SILENT --allow-empty
int main() {
// CHECKS-NOT: runtime error
- // CHECKU: negate-overflow.cpp:[[@LINE+2]]:3: runtime error: negation of 2147483648 cannot be represented in type 'unsigned int'
+ // CHECKU: negate-overflow.cpp:[[@LINE+3]]:3: runtime error: negation of 2147483648 cannot be represented in type 'unsigned int'
// CHECKU-NOT: cast to an unsigned
+ // CHECKU-SILENT-NOT: runtime error
-unsigned(-0x7fffffff - 1); // ok
// CHECKS: negate-overflow.cpp:[[@LINE+2]]:3: runtime error: negation of -2147483648 cannot be represented in type 'int'; cast to an unsigned type to negate this value to itself
// CHECKU-NOT: runtime error
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