Document -fno-sanitize-recover and -fsanitize-undefined-trap-on-error and attempt to explain the difference between them.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182890 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/UsersManual.rst b/docs/UsersManual.rst
index e881f15..3622a17 100644
--- a/docs/UsersManual.rst
+++ b/docs/UsersManual.rst
@@ -889,13 +889,12 @@
includes all of the checks listed below other than
``unsigned-integer-overflow``.
- ``-fsanitize=undefined-trap``: This includes all sanitizers
+ - ``-fsanitize=undefined-trap``: This includes all sanitizers
included by ``-fsanitize=undefined``, except those that require
- runtime support. This group of sanitizers are generally used
- in conjunction with the ``-fsanitize-undefined-trap-on-error``
- flag, which causes traps to be emitted, rather than calls to
- runtime libraries. This includes all of the checks listed below
- other than ``unsigned-integer-overflow`` and ``vptr``.
+ runtime support. This group of sanitizers is intended to be
+ used in conjunction with the ``-fsanitize-undefined-trap-on-error``
+ flag. This includes all of the checks listed below other than
+ ``unsigned-integer-overflow`` and ``vptr``.
The following more fine-grained checks are also available:
@@ -958,6 +957,19 @@
uninitialized bits came from. Slows down execution by additional
1.5x-2x.
+ Extra features of UndefinedBehaviorSanitizer:
+
+ - ``-fno-sanitize-recover``: By default, after a sanitizer diagnoses
+ an issue, it will attempt to continue executing the program if there
+ is a reasonable behavior it can give to the faulting operation. This
+ option causes the program to abort instead.
+ - ``-fsanitize-undefined-trap-on-error``: Causes traps to be emitted
+ rather than calls to runtime libraries when a problem is detected.
+ This option is intended for use in cases where the sanitizer runtime
+ cannot be used (for instance, when building libc or a kernel module).
+ This is only compatible with the sanitizers in the ``undefined-trap``
+ group.
+
The ``-fsanitize=`` argument must also be provided when linking, in
order to link to the appropriate runtime library. It is not possible
to combine the ``-fsanitize=address`` and ``-fsanitize=thread``