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/* GNU Objective C Runtime native exceptions
Copyright (C) 2010-2017 Free Software Foundation, Inc.
Contributed by Nicola Pero <>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<>. */
#ifndef __objc_exception_INCLUDE_GNU
#define __objc_exception_INCLUDE_GNU
#include "objc.h"
#include "objc-decls.h"
#ifdef __cplusplus
extern "C" {
/* 'objc_exception_throw' throws the exception 'exception', which is
an exception object.
Calls to 'objc_exception_throw' are automatically generated by the
compiler: an Objective-C "@throw exception;" statement gets
compiled into the equivalent of "objc_exception_throw
'objc_exception_throw' searches for a @catch() that can catch the
exception. By default, @catch (MyClass object) will catch all
exception objects that are of class MyClass or of a subclass of
MyClass; if the exception object is 'nil', then the exception can
only be caught with a catch-all exception handler where no
exception class is specified (such as @catch(id object)). This
behaviour can be customized by setting an 'objc_exception_matcher'
function (using objc_set_exception_matcher(), see below); if one is
set, it is used instead of the default one.
If the exception is uncaught (there is no @catch() to catch it),
the program aborts. It is possible to customize this behaviour by
setting an 'objc_uncaught_exception_handler' function (using
objc_set_uncaught_exception_handler(), see below); if one is set,
it is executed before abort() is called. An uncaught exception
handler is expected to never return. */
objc_EXPORT void objc_exception_throw (id exception);
/* Compatibility note: the Apple/NeXT runtime seems to also have
objc_exception_rethrow(), objc_begin_catch() and objc_end_catch().
Currently the GNU runtime does not use them. */
/* The following functions allow customizing to a certain extent the
exception handling. They are not thread safe and should be called
during the program initialization before threads are started. They
are mostly reserved for "Foundation" libraries; in the case of
GNUstep, GNUstep Base may be using these functions to improve the
standard exception handling. You probably shouldn't use these
functions unless you are writing your own Foundation library. */
/* Compatibility note: objc_set_exception_preprocessor() (available on
the Apple/NeXT runtime) is not available on the GNU runtime. */
/* An 'objc_exception_matcher' function is used to match an exception
to a @catch clause. 'catch_class' is the class of objects caught
by the @catch clause (for example, in "@catch (Object *o)", the
catch_class is Object). It should return 1 if the exception should
be caught by a @catch with a catch_class argument, and 0 if
not. */
typedef int (*objc_exception_matcher)(Class catch_class, id exception);
/* Sets a new exception matcher function, and returns the previous
exception matcher function. This function is not safe to call in a
multi-threaded environment because other threads may be trying to
invoke the exception matcher while you change it! */
objc_EXPORT objc_exception_matcher
objc_setExceptionMatcher (objc_exception_matcher new_matcher);
/* An 'objc_uncaught_exception_handler' function is a function that
handles uncaught exceptions. It should never return. */
typedef void (*objc_uncaught_exception_handler)(id exception);
/* Sets a new uncaught exception handler function, and returns the
previous exception handler function. This function is not safe to
call in a multi-threaded environment because other threads may be
trying to invoke the uncaught exception handler while you change
it. */
objc_EXPORT objc_uncaught_exception_handler
objc_setUncaughtExceptionHandler (objc_uncaught_exception_handler new_handler);
#ifdef __cplusplus
#endif /* not __objc_exception_INCLUDE_GNU */