r335762 - [UBSan] Add silence_unsigned_overflow flag.

[Matt Morehouse via cfe-commits]

Author: morehouse
Date: Wed Jun 27 11:24:46 2018
New Revision: 335762

URL: http://llvm.org/viewvc/llvm-project?rev=335762&view=rev
Log:
[UBSan] Add silence_unsigned_overflow flag.

Summary:
Setting UBSAN_OPTIONS=silence_unsigned_overflow=1 will silence all UIO
reports.  This feature, combined with
-fsanitize-recover=unsigned-integer-overflow, is useful for providing
fuzzing signal without the excessive log output.

Helps with https://github.com/google/oss-fuzz/issues/910.

Reviewers: kcc, vsk

Reviewed By: vsk

Subscribers: vsk, kubamracek, Dor1s, llvm-commits

Differential Revision: https://reviews.llvm.org/D48660

Modified:
    cfe/trunk/docs/UndefinedBehaviorSanitizer.rst

Modified: cfe/trunk/docs/UndefinedBehaviorSanitizer.rst
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/docs/UndefinedBehaviorSanitizer.rst?rev=335762&r1=335761&r2=335762&view=diff
==============================================================================
--- cfe/trunk/docs/UndefinedBehaviorSanitizer.rst (original)
+++ cfe/trunk/docs/UndefinedBehaviorSanitizer.rst Wed Jun 27 11:24:46 2018
@@ -180,6 +180,13 @@ will need to:
    ``UBSAN_OPTIONS=print_stacktrace=1``.
 #. Make sure ``llvm-symbolizer`` binary is in ``PATH``.
 
+Silencing Unsigned Integer Overflow
+===================================
+To silence reports from unsigned integer overflow, you can set
+``UBSAN_OPTIONS=silence_unsigned_overflow=1``.  This feature, combined with
+``-fsanitize-recover=unsigned-integer-overflow``, is particularly useful for
+providing fuzzing signal without blowing up logs.
+
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