[docs] Add some ubsan changes to the release notes
llvm-svn: 305269
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index f7e31e5..f9a3317 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -187,6 +187,31 @@
...
+Undefined Behavior Sanitizer (UBSan)
+------------------------------------
+
+- The Undefined Behavior Sanitizer has a new check for pointer overflow. This
+ check is on by default. The flag to control this functionality is
+ -fsanitize=pointer-overflow.
+
+ Pointer overflow is an indicator of undefined behavior: when a pointer
+ indexing expression wraps around the address space, or produces other
+ unexpected results, its result may not point to a valid object.
+
+- UBSan has several new checks which detect violations of nullability
+ annotations. These checks are off by default. The flag to control this group
+ of checks is -fsanitize=nullability. The checks can be individially enabled
+ by -fsanitize=nullability-arg (which checks calls),
+ -fsanitize=nullability-assign (which checks assignments), and
+ -fsanitize=nullability-return (which checks return statements).
+
+- UBSan can now detect invalid loads from bitfields and from ObjC BOOLs.
+
+- UBSan can now avoid emitting unnecessary type checks in C++ class methods and
+ in several other cases where the result is known at compile-time. UBSan can
+ also avoid emitting unnecessary overflow checks in arithmetic expressions
+ with promoted integer operands.
+
Core Analysis Improvements
==========================