[PATCH] D27455: UBSan docs: Explicitly mention that `-fsanitize=unsigned-integer-overflow` does not catch UB.

[Nico Weber via Phabricator via cfe-commits]

thakis created this revision.
thakis added reviewers: rsmith, samsonov.
thakis added a subscriber: cfe-commits.

https://reviews.llvm.org/D27455

Files:
  docs/UndefinedBehaviorSanitizer.rst


Index: docs/UndefinedBehaviorSanitizer.rst
===================================================================
--- docs/UndefinedBehaviorSanitizer.rst
+++ docs/UndefinedBehaviorSanitizer.rst
@@ -117,7 +117,9 @@
   -  ``-fsanitize=unreachable``: If control flow reaches
      ``__builtin_unreachable``.
   -  ``-fsanitize=unsigned-integer-overflow``: Unsigned integer
-     overflows.
+     overflows. Note that unlike signed integer overflow, unsigned integer
+     is not undefined behavior. However, while it has well-defined semantics,
+     it is often unintentional, so UBSan offers to catch it.
   -  ``-fsanitize=vla-bound``: A variable-length array whose bound
      does not evaluate to a positive value.
   -  ``-fsanitize=vptr``: Use of an object whose vptr indicates that


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D27455.80412.patch
Type: text/x-patch
Size: 784 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20161206/6290db86/attachment.bin>