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Diffstat (limited to 'clang/docs/LanguageExtensions.rst')
| -rw-r--r-- | clang/docs/LanguageExtensions.rst | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst index 7b23e4d1c2f3..1ad7c822c5b8 100644 --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -3464,6 +3464,34 @@ Query for this feature with ``__has_builtin(__builtin_trap)``. ``__builtin_arm_trap`` is lowered to the ``llvm.aarch64.break`` builtin, and then to ``brk #payload``. +``__builtin_allow_runtime_check`` +--------------------------------- + +``__builtin_allow_runtime_check`` return true if the check at the current program location should be executed. + +**Syntax**: + +.. code-block:: c++ + + bool __builtin_allow_runtime_check(const char* kind) + +**Example of use**: + +.. code-block:: c++ + + if (__builtin_allow_runtime_check("mycheck") && !ExpensiveCheck()) { + abort(); + } + +**Description** + +``__builtin_allow_runtime_check`` is lowered to ` ``llvm.allow.runtime.check`` <https://llvm.org/docs/LangRef.html#llvm-allow-runtime-check-intrinsic>`_ builtin. + +The ``__builtin_allow_runtime_check()`` builtin is typically used with control flow +conditions such as in ``if`` to guard expensive runtime checks. The specific rules for selecting permitted checks can differ and are controlled by the compiler options. + +Query for this feature with ``__has_builtin(__builtin_allow_runtime_check)``. + ``__builtin_nondeterministic_value`` ------------------------------------ |