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| author | Vedant Kumar <vsk@apple.com> | 2017-07-29 00:19:51 +0000 |
|---|---|---|
| committer | Vedant Kumar <vsk@apple.com> | 2017-07-29 00:19:51 +0000 |
| commit | 081dca929f7dc72b99e53622bff71d21c9519ffb (patch) | |
| tree | 5a28a96f2b28d6041a91b17ffeacf9255be72d07 /docs | |
| parent | 8c94133f92df7c2e36e8ac0fa31011f2e54b5f3e (diff) | |
| download | clang-081dca929f7dc72b99e53622bff71d21c9519ffb.tar.gz | |
[ubsan] Diagnose invalid uses of builtins (clang)
On some targets, passing zero to the clz() or ctz() builtins has undefined
behavior. I ran into this issue while debugging UB in __hash_table from libcxx:
the bug I was seeing manifested itself differently under -O0 vs -Os, due to a
UB call to clz() (see: libcxx/r304617).
This patch introduces a check which can detect UB calls to builtins.
llvm.org/PR26979
Differential Revision: https://reviews.llvm.org/D34590
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309459 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/UndefinedBehaviorSanitizer.rst | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/docs/UndefinedBehaviorSanitizer.rst b/docs/UndefinedBehaviorSanitizer.rst index 95c3ebfaca..6274054a46 100644 --- a/docs/UndefinedBehaviorSanitizer.rst +++ b/docs/UndefinedBehaviorSanitizer.rst @@ -75,6 +75,7 @@ Available checks are: of a misaligned reference. - ``-fsanitize=bool``: Load of a ``bool`` value which is neither ``true`` nor ``false``. + - ``-fsanitize=builtin``: Passing invalid values to compiler builtins. - ``-fsanitize=bounds``: Out of bounds array indexing, in cases where the array bound can be statically determined. - ``-fsanitize=enum``: Load of a value of an enumerated type which |