UBSan docs: Explicitly mention that `-fsanitize=unsigned-integer-overflow` does not...

https://reviews.llvm.org/D27455

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@296387 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/UndefinedBehaviorSanitizer.rst b/docs/UndefinedBehaviorSanitizer.rst
index 09ee78f5876df4dcd19c6558feccfc53826601f2..7ff7be931844df8d351cc9d45154176988cf938d 100644 (file)
--- a/docs/UndefinedBehaviorSanitizer.rst
+++ b/docs/UndefinedBehaviorSanitizer.rst
@@ -117,7 +117,9 @@ Available checks are:
   -  ``-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