Commit Graph

3 Commits

Author SHA1 Message Date
Vedant Kumar 6b22dda5a3 [ubsan] nullability-assign: Check assignments into C++ structs
Fix the nullability-assign check so that it can handle assignments into
C++ structs. Previously, such assignments were not instrumented.

Testing: check-clang, check-ubsan, enabling the existing test in ObjC++
mode, and building some Apple frameworks with -fsanitize=nullability.

llvm-svn: 301482
2017-04-26 21:55:17 +00:00
Vedant Kumar 2b9f48afdd [ubsan] Use the nicer nullability diagnostic handlers
This is a follow-up to r297700 (Add a nullability sanitizer).

It addresses some FIXME's re: using nullability-specific diagnostic
handlers from compiler-rt, now that the necessary handlers exist.

check-ubsan test updates to follow.

llvm-svn: 297750
2017-03-14 16:48:29 +00:00
Vedant Kumar 42c17ec5ac [ubsan] Add a nullability sanitizer
Teach UBSan to detect when a value with the _Nonnull type annotation
assumes a null value. Call expressions, initializers, assignments, and
return statements are all checked.

Because _Nonnull does not affect IRGen, the new checks are disabled by
default. The new driver flags are:

  -fsanitize=nullability-arg      (_Nonnull violation in call)
  -fsanitize=nullability-assign   (_Nonnull violation in assignment)
  -fsanitize=nullability-return   (_Nonnull violation in return stmt)
  -fsanitize=nullability          (all of the above)

This patch builds on top of UBSan's existing support for detecting
violations of the nonnull attributes ('nonnull' and 'returns_nonnull'),
and relies on the compiler-rt support for those checks. Eventually we
will need to update the diagnostic messages in compiler-rt (there are
FIXME's for this, which will be addressed in a follow-up).

One point of note is that the nullability-return check is only allowed
to kick in if all arguments to the function satisfy their nullability
preconditions. This makes it necessary to emit some null checks in the
function body itself.

Testing: check-clang and check-ubsan. I also built some Apple ObjC
frameworks with an asserts-enabled compiler, and verified that we get
valid reports.

Differential Revision: https://reviews.llvm.org/D30762

llvm-svn: 297700
2017-03-14 01:56:34 +00:00