(``STB_LOCAL`` in the case of ELF) in the object file. This
corresponds to the notion of the '``static``' keyword in C.
``available_externally``
- Globals with "``available_externally``" linkage are never emitted
- into the object file corresponding to the LLVM module. They exist to
- allow inlining and other optimizations to take place given knowledge
- of the definition of the global, which is known to be somewhere
- outside the module. Globals with ``available_externally`` linkage
- are allowed to be discarded at will, and are otherwise the same as
- ``linkonce_odr``. This linkage type is only allowed on definitions,
- not declarations.
+ Globals with "``available_externally``" linkage are never emitted into
+ the object file corresponding to the LLVM module. From the linker's
+ perspective, an ``available_externally`` global is equivalent to
+ an external declaration. They exist to allow inlining and other
+ optimizations to take place given knowledge of the definition of the
+ global, which is known to be somewhere outside the module. Globals
+ with ``available_externally`` linkage are allowed to be discarded at
+ will, and allow inlining and other optimizations. This linkage type is
+ only allowed on definitions, not declarations.
``linkonce``
Globals with "``linkonce``" linkage are merged with other globals of
the same name when linkage occurs. This can be used to implement
':ref:`resume <i_resume>`', ':ref:`catchswitch <i_catchswitch>`',
':ref:`catchret <i_catchret>`',
':ref:`cleanupret <i_cleanupret>`',
-':ref:`terminatepad <i_terminatepad>`',
and ':ref:`unreachable <i_unreachable>`'.
.. _i_ret:
.. _i_catchswitch:
'``catchswitch``' Instruction
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Syntax:
"""""""
this operand may be the token ``none``.
The ``default`` argument is the label of another basic block beginning with a
-"pad" instruction, one of ``cleanuppad``, ``terminatepad``, or
-``catchswitch``.
+"pad" instruction, one of ``cleanuppad`` or ``catchswitch``.
The ``handlers`` are a list of successor blocks that each begin with a
:ref:`catchpad <i_catchpad>` instruction.
.. _i_catchpad:
'``catchpad``' Instruction
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+^^^^^^^^^^^^^^^^^^^^^^^^^^
Syntax:
"""""""
is undefined behavior if any descendant pads have been entered but not yet
exited.
2) implicitly via a call (which unwinds all the way to the current function's caller),
- or via a ``catchswitch``, ``cleanupret``, or ``terminatepad`` that unwinds to caller.
+ or via a ``catchswitch`` or a ``cleanupret`` that unwinds to caller.
3) implicitly via an unwind edge whose destination EH pad isn't a descendant of
the ``catchpad``. When the ``catchpad`` is exited in this manner, it is
undefined behavior if the destination EH pad has a parent which is not an
cleanupret from %cleanup unwind to caller
cleanupret from %cleanup unwind label %continue
-.. _i_terminatepad:
-
-'``terminatepad``' Instruction
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Syntax:
-"""""""
-
-::
-
- terminatepad within <token> [<args>*] unwind label <exception label>
- terminatepad within <token> [<args>*] unwind to caller
-
-Overview:
-"""""""""
-
-The '``terminatepad``' instruction is used by `LLVM's exception handling
-system <ExceptionHandling.html#overview>`_ to specify that a basic block
-is a terminate block --- one where a personality routine may decide to
-terminate the program.
-The ``args`` correspond to whatever information the personality
-routine requires to know if this is an appropriate place to terminate the
-program. Control is transferred to the ``exception`` label if the
-personality routine decides not to terminate the program for the
-in-flight exception.
-
-Arguments:
-""""""""""
-
-The instruction takes a list of arbitrary values which are interpreted
-by the :ref:`personality function <personalityfn>`.
-
-The ``terminatepad`` may be given an ``exception`` label to
-transfer control to if the in-flight exception matches the ``args``.
-
-Semantics:
-""""""""""
-
-When the call stack is being unwound due to an exception being thrown,
-the exception is compared against the ``args``. If it matches,
-then control is transfered to the ``exception`` basic block. Otherwise,
-the program is terminated via personality-specific means. Typically,
-the first argument to ``terminatepad`` specifies what function the
-personality should defer to in order to terminate the program.
-
-The ``terminatepad`` instruction is both a terminator and a "pad" instruction,
-meaning that is always the only non-phi instruction in the basic block.
-
-Example:
-""""""""
-
-.. code-block:: llvm
-
- ;; A terminate block which only permits integers.
- terminatepad within none [i8** @_ZTIi] unwind label %continue
-
.. _i_unreachable:
'``unreachable``' Instruction
is undefined behavior if any descendant pads have been entered but not yet
exited.
2) implicitly via a call (which unwinds all the way to the current function's caller),
- or via a ``catchswitch``, ``cleanupret``, or ``terminatepad`` that unwinds to caller.
+ or via a ``catchswitch`` or a ``cleanupret`` that unwinds to caller.
3) implicitly via an unwind edge whose destination EH pad isn't a descendant of
the ``cleanuppad``. When the ``cleanuppad`` is exited in this manner, it is
undefined behavior if the destination EH pad has a parent which is not an
projects / oota-llvm.git / blobdiff