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Diffstat (limited to 'docs/UndefinedBehaviorSanitizer.rst')
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diff --git a/docs/UndefinedBehaviorSanitizer.rst b/docs/UndefinedBehaviorSanitizer.rst index 37ff16d9a9e9b..2a133501dd952 100644 --- a/docs/UndefinedBehaviorSanitizer.rst +++ b/docs/UndefinedBehaviorSanitizer.rst @@ -168,6 +168,38 @@ UndefinedBehaviorSanitizer supports ``src`` and ``fun`` entity types in :doc:`SanitizerSpecialCaseList`, that can be used to suppress error reports in the specified source files or functions. +Runtime suppressions +-------------------- + +Sometimes you can suppress UBSan error reports for specific files, functions, +or libraries without recompiling the code. You need to pass a path to +suppression file in a ``UBSAN_OPTIONS`` environment variable. + +.. code-block:: bash + + UBSAN_OPTIONS=suppressions=MyUBSan.supp + +You need to specify a :ref:`check <ubsan-checks>` you are suppressing and the +bug location. For example: + +.. code-block:: bash + + signed-integer-overflow:file-with-known-overflow.cpp + alignment:function_doing_unaligned_access + vptr:shared_object_with_vptr_failures.so + +There are several limitations: + +* Sometimes your binary must have enough debug info and/or symbol table, so + that the runtime could figure out source file or function name to match + against the suppression. +* It is only possible to suppress recoverable checks. For the example above, + you can additionally pass + ``-fsanitize-recover=signed-integer-overflow,alignment,vptr``, although + most of UBSan checks are recoverable by default. +* Check groups (like ``undefined``) can't be used in suppressions file, only + fine-grained checks are supported. + Supported Platforms =================== |