gcc/libobjc/methods.c

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/* GNU Objective C Runtime method related functions.
Copyright (C) 2010-2018 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 MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the 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
<http://www.gnu.org/licenses/>. */
#include "objc-private/common.h"
#include "objc/runtime.h"
#include "objc-private/module-abi-8.h" /* For runtime structures. */
#include "objc/thr.h"
#include "objc-private/runtime.h" /* For __objc_runtime_mutex. */
#include <stdlib.h> /* For malloc. */
SEL
method_getName (struct objc_method * method)
{
if (method == NULL)
return NULL;
return method->method_name;
}
const char *
method_getTypeEncoding (struct objc_method * method)
{
if (method == NULL)
return NULL;
return method->method_types;
}
IMP
method_getImplementation (struct objc_method * method)
{
if (method == NULL)
return NULL;
return method->method_imp;
}
struct objc_method_description *
method_getDescription (struct objc_method * method)
{
/* Note that the following returns NULL if method is NULL, which is
fine. */
return (struct objc_method_description *)method;
}
struct objc_method **
class_copyMethodList (Class class_, unsigned int *numberOfReturnedMethods)
{
unsigned int count = 0;
struct objc_method **returnValue = NULL;
struct objc_method_list* method_list;
if (class_ == Nil)
{
if (numberOfReturnedMethods)
*numberOfReturnedMethods = 0;
return NULL;
}
/* Lock the runtime mutex because the class methods may be
concurrently modified. */
objc_mutex_lock (__objc_runtime_mutex);
/* Count how many methods we have. */
method_list = class_->methods;
while (method_list)
{
count = count + method_list->method_count;
method_list = method_list->method_next;
}
if (count != 0)
{
unsigned int i = 0;
/* Allocate enough memory to hold them. */
returnValue
= (struct objc_method **)(malloc (sizeof (struct objc_method *)
* (count + 1)));
/* Copy the methods. */
method_list = class_->methods;
while (method_list)
{
int j;
for (j = 0; j < method_list->method_count; j++)
{
returnValue[i] = &(method_list->method_list[j]);
i++;
}
method_list = method_list->method_next;
}
returnValue[i] = NULL;
}
objc_mutex_unlock (__objc_runtime_mutex);
if (numberOfReturnedMethods)
*numberOfReturnedMethods = count;
return returnValue;
}
IMP
method_setImplementation (struct objc_method * method, IMP implementation)
{
IMP old_implementation;
if (method == NULL || implementation == NULL)
return NULL;
/* We lock the runtime mutex so that concurrent calls to change the
same method won't conflict with each other. */
objc_mutex_lock (__objc_runtime_mutex);
old_implementation = method->method_imp;
method->method_imp = implementation;
/* That was easy :-). But now we need to find all classes that use
this method, and update the IMP in the dispatch tables. */
__objc_update_classes_with_methods (method, NULL);
objc_mutex_unlock (__objc_runtime_mutex);
return old_implementation;
}
void
method_exchangeImplementations (struct objc_method * method_a, struct objc_method * method_b)
{
IMP old_implementation_a;
IMP old_implementation_b;
if (method_a == NULL || method_b == NULL)
return;
/* We lock the runtime mutex so that concurrent calls to exchange
similar methods won't conflict with each other. Each of them
should be atomic. */
objc_mutex_lock (__objc_runtime_mutex);
old_implementation_a = method_a->method_imp;
old_implementation_b = method_b->method_imp;
method_a->method_imp = old_implementation_b;
method_b->method_imp = old_implementation_a;
/* That was easy :-). But now we need to find all classes that use
these methods, and update the IMP in the dispatch tables. */
__objc_update_classes_with_methods (method_a, method_b);
objc_mutex_unlock (__objc_runtime_mutex);
}