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Diffstat (limited to 'docs/LangRef.rst')
| -rw-r--r-- | docs/LangRef.rst | 44 |
1 files changed, 30 insertions, 14 deletions
diff --git a/docs/LangRef.rst b/docs/LangRef.rst index 0996820f724f..ef9fd92d2e56 100644 --- a/docs/LangRef.rst +++ b/docs/LangRef.rst @@ -635,8 +635,9 @@ attributes <paramattrs>`), optional :ref:`function attributes <fnattrs>`, an optional section, an optional alignment, an optional :ref:`comdat <langref_comdats>`, an optional :ref:`garbage collector name <gc>`, an optional :ref:`prefix <prefixdata>`, -an optional :ref:`prologue <prologuedata>`, an opening -curly brace, a list of basic blocks, and a closing curly brace. +an optional :ref:`prologue <prologuedata>`, +an optional :ref:`personality <personalityfn>`, +an opening curly brace, a list of basic blocks, and a closing curly brace. LLVM function declarations consist of the "``declare``" keyword, an optional :ref:`linkage type <linkage>`, an optional :ref:`visibility @@ -683,7 +684,8 @@ Syntax:: [cconv] [ret attrs] <ResultType> @<FunctionName> ([argument list]) [unnamed_addr] [fn Attrs] [section "name"] [comdat [($name)]] - [align N] [gc] [prefix Constant] [prologue Constant] { ... } + [align N] [gc] [prefix Constant] [prologue Constant] + [personality Constant] { ... } The argument list is a comma seperated sequence of arguments where each argument is of the following form @@ -1130,6 +1132,14 @@ A function may have prologue data but no body. This has similar semantics to the ``available_externally`` linkage in that the data may be used by the optimizers but will not be emitted in the object file. +.. _personalityfn: + +Personality Function +-------------------- + +The ``personality`` attribute permits functions to specify what function +to use for exception handling. + .. _attrgrp: Attribute Groups @@ -1319,6 +1329,15 @@ example: ``setjmp`` is an example of such a function. The compiler disables some optimizations (like tail calls) in the caller of these functions. +``safestack`` + This attribute indicates that + `SafeStack <http://clang.llvm.org/docs/SafeStack.html>`_ + protection is enabled for this function. + + If a function that has a ``safestack`` attribute is inlined into a + function that doesn't have a ``safestack`` attribute or which has an + ``ssp``, ``sspstrong`` or ``sspreq`` attribute, then the resulting + function will have a ``safestack`` attribute. ``sanitize_address`` This attribute indicates that AddressSanitizer checks (dynamic address safety analysis) are enabled for this function. @@ -7274,8 +7293,8 @@ Syntax: :: - <resultval> = landingpad <resultty> personality <type> <pers_fn> <clause>+ - <resultval> = landingpad <resultty> personality <type> <pers_fn> cleanup <clause>* + <resultval> = landingpad <resultty> <clause>+ + <resultval> = landingpad <resultty> cleanup <clause>* <clause> := catch <type> <value> <clause> := filter <array constant type> <array constant> @@ -7287,14 +7306,13 @@ The '``landingpad``' instruction is used by `LLVM's exception handling system <ExceptionHandling.html#overview>`_ to specify that a basic block is a landing pad --- one where the exception lands, and corresponds to the code found in the ``catch`` portion of a ``try``/``catch`` sequence. It -defines values supplied by the personality function (``pers_fn``) upon +defines values supplied by the :ref:`personality function <personalityfn>` upon re-entry to the function. The ``resultval`` has the type ``resultty``. Arguments: """""""""" -This instruction takes a ``pers_fn`` value. This is the personality -function associated with the unwinding mechanism. The optional +The optional ``cleanup`` flag indicates that the landing pad block is a cleanup. A ``clause`` begins with the clause type --- ``catch`` or ``filter`` --- and @@ -7309,7 +7327,7 @@ Semantics: """""""""" The '``landingpad``' instruction defines the values which are set by the -personality function (``pers_fn``) upon re-entry to the function, and +:ref:`personality function <personalityfn>` upon re-entry to the function, and therefore the "result type" of the ``landingpad`` instruction. As with calling conventions, how the personality function results are represented in LLVM IR is target specific. @@ -7332,8 +7350,6 @@ The ``landingpad`` instruction has several restrictions: pad block. - A basic block that is not a landing pad block may not include a '``landingpad``' instruction. -- All '``landingpad``' instructions in a function must have the same - personality function. Example: """""""" @@ -7341,13 +7357,13 @@ Example: .. code-block:: llvm ;; A landing pad which can catch an integer. - %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0 + %res = landingpad { i8*, i32 } catch i8** @_ZTIi ;; A landing pad that is a cleanup. - %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0 + %res = landingpad { i8*, i32 } cleanup ;; A landing pad which can catch an integer and can only throw a double. - %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0 + %res = landingpad { i8*, i32 } catch i8** @_ZTIi filter [1 x i8**] [@_ZTId] |