mirror of
https://github.com/autc04/Retro68.git
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1165 lines
38 KiB
C
1165 lines
38 KiB
C
/* GNU Objective C Runtime message lookup
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Copyright (C) 1993-2018 Free Software Foundation, Inc.
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Contributed by Kresten Krab Thorup
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under the
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terms of the GNU General Public License as published by the Free Software
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Foundation; either version 3, or (at your option) any later version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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/* Uncommented the following line to enable debug logging. Use this
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only while debugging the runtime. */
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/* #define DEBUG 1 */
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/* FIXME: This should be using libffi instead of __builtin_apply
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and friends. */
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#include "objc-private/common.h"
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#include "objc-private/error.h"
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#include "tconfig.h"
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#include "coretypes.h"
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#include "objc/runtime.h"
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#include "objc/message.h" /* For objc_msg_lookup(), objc_msg_lookup_super(). */
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#include "objc/thr.h"
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#include "objc-private/module-abi-8.h"
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#include "objc-private/runtime.h"
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#include "objc-private/hash.h"
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#include "objc-private/sarray.h"
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#include "objc-private/selector.h" /* For sel_is_mapped() */
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#include "runtime-info.h"
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#include <assert.h> /* For assert */
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#include <string.h> /* For strlen */
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#define INVISIBLE_STRUCT_RETURN 1
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/* The uninstalled dispatch table. If a class' dispatch table points
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to __objc_uninstalled_dtable then that means it needs its dispatch
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table to be installed. */
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struct sarray *__objc_uninstalled_dtable = 0; /* !T:MUTEX */
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/* Two hooks for method forwarding. If either is set, it is invoked to
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* return a function that performs the real forwarding. If both are
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* set, the result of __objc_msg_forward2 will be preferred over that
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* of __objc_msg_forward. If both return NULL or are unset, the
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* libgcc based functions (__builtin_apply and friends) are used. */
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IMP (*__objc_msg_forward) (SEL) = NULL;
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IMP (*__objc_msg_forward2) (id, SEL) = NULL;
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/* Send +initialize to class. */
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static void __objc_send_initialize (Class);
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/* Forward declare some functions */
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static void __objc_install_dtable_for_class (Class cls);
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static void __objc_prepare_dtable_for_class (Class cls);
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static void __objc_install_prepared_dtable_for_class (Class cls);
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static struct sarray *__objc_prepared_dtable_for_class (Class cls);
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static IMP __objc_get_prepared_imp (Class cls,SEL sel);
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/* Various forwarding functions that are used based upon the
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return type for the selector.
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__objc_block_forward for structures.
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__objc_double_forward for floats/doubles.
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__objc_word_forward for pointers or types that fit in registers. */
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static double __objc_double_forward (id, SEL, ...);
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static id __objc_word_forward (id, SEL, ...);
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typedef struct { id many[8]; } __big;
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#if INVISIBLE_STRUCT_RETURN
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static __big
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#else
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static id
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#endif
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__objc_block_forward (id, SEL, ...);
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static struct objc_method * search_for_method_in_hierarchy (Class class, SEL sel);
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struct objc_method * search_for_method_in_list (struct objc_method_list * list, SEL op);
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id nil_method (id, SEL);
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/* Make sure this inline function is exported regardless of GNU89 or C99
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inlining semantics as it is part of the libobjc ABI. */
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extern IMP __objc_get_forward_imp (id, SEL);
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/* Given a selector, return the proper forwarding implementation. */
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inline
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IMP
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__objc_get_forward_imp (id rcv, SEL sel)
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{
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/* If a custom forwarding hook was registered, try getting a
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forwarding function from it. There are two forward routine hooks,
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one that takes the receiver as an argument and one that does
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not. */
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if (__objc_msg_forward2)
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{
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IMP result;
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if ((result = __objc_msg_forward2 (rcv, sel)) != NULL)
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return result;
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}
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if (__objc_msg_forward)
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{
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IMP result;
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if ((result = __objc_msg_forward (sel)) != NULL)
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return result;
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}
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/* In all other cases, use the default forwarding functions built
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using __builtin_apply and friends. */
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{
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const char *t = sel->sel_types;
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if (t && (*t == '[' || *t == '(' || *t == '{')
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#ifdef OBJC_MAX_STRUCT_BY_VALUE
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&& objc_sizeof_type (t) > OBJC_MAX_STRUCT_BY_VALUE
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#endif
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)
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return (IMP)__objc_block_forward;
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else if (t && (*t == 'f' || *t == 'd'))
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return (IMP)__objc_double_forward;
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else
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return (IMP)__objc_word_forward;
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}
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}
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/* Selectors for +resolveClassMethod: and +resolveInstanceMethod:.
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These are set up at startup. */
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static SEL selector_resolveClassMethod = NULL;
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static SEL selector_resolveInstanceMethod = NULL;
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/* Internal routines use to resolve a class method using
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+resolveClassMethod:. 'class' is always a non-Nil class (*not* a
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meta-class), and 'sel' is the selector that we are trying to
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resolve. This must be called when class is not Nil, and the
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dispatch table for class methods has already been installed.
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This routine tries to call +resolveClassMethod: to give an
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opportunity to resolve the method. If +resolveClassMethod: returns
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YES, it tries looking up the method again, and if found, it returns
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it. Else, it returns NULL. */
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static inline
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IMP
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__objc_resolve_class_method (Class class, SEL sel)
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{
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/* We need to lookup +resolveClassMethod:. */
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BOOL (*resolveMethodIMP) (id, SEL, SEL);
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/* The dispatch table for class methods is already installed and we
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don't want any forwarding to happen when looking up this method,
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so we just look it up directly. Note that if 'sel' is precisely
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+resolveClassMethod:, this would look it up yet again and find
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nothing. That's no problem and there's no recursion. */
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resolveMethodIMP = (BOOL (*) (id, SEL, SEL))sarray_get_safe
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(class->class_pointer->dtable, (size_t) selector_resolveClassMethod->sel_id);
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if (resolveMethodIMP && resolveMethodIMP ((id)class, selector_resolveClassMethod, sel))
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{
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/* +resolveClassMethod: returned YES. Look the method up again.
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We already know the dtable is installed. */
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/* TODO: There is the case where +resolveClassMethod: is buggy
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and returned YES without actually adding the method. We
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could maybe print an error message. */
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return sarray_get_safe (class->class_pointer->dtable, (size_t) sel->sel_id);
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}
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return NULL;
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}
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/* Internal routines use to resolve a instance method using
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+resolveInstanceMethod:. 'class' is always a non-Nil class, and
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'sel' is the selector that we are trying to resolve. This must be
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called when class is not Nil, and the dispatch table for instance
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methods has already been installed.
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This routine tries to call +resolveInstanceMethod: to give an
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opportunity to resolve the method. If +resolveInstanceMethod:
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returns YES, it tries looking up the method again, and if found, it
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returns it. Else, it returns NULL. */
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static inline
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IMP
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__objc_resolve_instance_method (Class class, SEL sel)
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{
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/* We need to lookup +resolveInstanceMethod:. */
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BOOL (*resolveMethodIMP) (id, SEL, SEL);
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/* The dispatch table for class methods may not be already installed
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so we have to install it if needed. */
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resolveMethodIMP = sarray_get_safe (class->class_pointer->dtable,
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(size_t) selector_resolveInstanceMethod->sel_id);
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if (resolveMethodIMP == 0)
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{
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/* Try again after installing the dtable. */
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if (class->class_pointer->dtable == __objc_uninstalled_dtable)
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{
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objc_mutex_lock (__objc_runtime_mutex);
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if (class->class_pointer->dtable == __objc_uninstalled_dtable)
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__objc_install_dtable_for_class (class->class_pointer);
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objc_mutex_unlock (__objc_runtime_mutex);
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}
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resolveMethodIMP = sarray_get_safe (class->class_pointer->dtable,
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(size_t) selector_resolveInstanceMethod->sel_id);
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}
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if (resolveMethodIMP && resolveMethodIMP ((id)class, selector_resolveInstanceMethod, sel))
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{
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/* +resolveInstanceMethod: returned YES. Look the method up
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again. We already know the dtable is installed. */
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/* TODO: There is the case where +resolveInstanceMethod: is
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buggy and returned YES without actually adding the method.
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We could maybe print an error message. */
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return sarray_get_safe (class->dtable, (size_t) sel->sel_id);
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}
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return NULL;
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}
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/* Given a CLASS and selector, return the implementation corresponding
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to the method of the selector.
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If CLASS is a class, the instance method is returned.
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If CLASS is a meta class, the class method is returned.
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Since this requires the dispatch table to be installed, this function
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will implicitly invoke +initialize for CLASS if it hasn't been
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invoked yet. This also insures that +initialize has been invoked
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when the returned implementation is called directly.
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The forwarding hooks require the receiver as an argument (if they are to
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perform dynamic lookup in proxy objects etc), so this function has a
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receiver argument to be used with those hooks. */
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static inline
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IMP
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get_implementation (id receiver, Class class, SEL sel)
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{
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void *res;
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if (class->dtable == __objc_uninstalled_dtable)
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{
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/* The dispatch table needs to be installed. */
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objc_mutex_lock (__objc_runtime_mutex);
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/* Double-checked locking pattern: Check
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__objc_uninstalled_dtable again in case another thread
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installed the dtable while we were waiting for the lock to be
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released. */
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if (class->dtable == __objc_uninstalled_dtable)
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__objc_install_dtable_for_class (class);
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/* If the dispatch table is not yet installed, we are still in
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the process of executing +initialize. But the implementation
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pointer should be available in the prepared ispatch table if
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it exists at all. */
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if (class->dtable == __objc_uninstalled_dtable)
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{
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assert (__objc_prepared_dtable_for_class (class) != 0);
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res = __objc_get_prepared_imp (class, sel);
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}
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else
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res = 0;
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objc_mutex_unlock (__objc_runtime_mutex);
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/* Call ourselves with the installed dispatch table and get the
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real method. */
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if (!res)
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res = get_implementation (receiver, class, sel);
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}
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else
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{
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/* The dispatch table has been installed. */
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res = sarray_get_safe (class->dtable, (size_t) sel->sel_id);
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if (res == 0)
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{
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/* The dispatch table has been installed, and the method is
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not in the dispatch table. So the method just doesn't
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exist for the class. */
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/* Try going through the +resolveClassMethod: or
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+resolveInstanceMethod: process. */
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if (CLS_ISMETA (class))
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{
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/* We have the meta class, but we need to invoke the
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+resolveClassMethod: method on the class. So, we
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need to obtain the class from the meta class, which
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we do using the fact that both the class and the
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meta-class have the same name. */
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Class realClass = objc_lookUpClass (class->name);
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if (realClass)
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res = __objc_resolve_class_method (realClass, sel);
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}
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else
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res = __objc_resolve_instance_method (class, sel);
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if (res == 0)
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res = __objc_get_forward_imp (receiver, sel);
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}
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}
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return res;
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}
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/* Make sure this inline function is exported regardless of GNU89 or C99
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inlining semantics as it is part of the libobjc ABI. */
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extern IMP get_imp (Class, SEL);
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inline
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IMP
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get_imp (Class class, SEL sel)
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{
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/* In a vanilla implementation we would first check if the dispatch
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table is installed. Here instead, to get more speed in the
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standard case (that the dispatch table is installed) we first try
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to get the imp using brute force. Only if that fails, we do what
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we should have been doing from the very beginning, that is, check
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if the dispatch table needs to be installed, install it if it's
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not installed, and retrieve the imp from the table if it's
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installed. */
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void *res = sarray_get_safe (class->dtable, (size_t) sel->sel_id);
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if (res == 0)
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{
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res = get_implementation(nil, class, sel);
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}
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return res;
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}
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/* The new name of get_imp(). */
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IMP
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class_getMethodImplementation (Class class_, SEL selector)
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{
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if (class_ == Nil || selector == NULL)
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return NULL;
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/* get_imp is inlined, so we're good. */
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return get_imp (class_, selector);
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}
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/* Given a method, return its implementation. This has been replaced
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by method_getImplementation() in the modern API. */
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IMP
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method_get_imp (struct objc_method * method)
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{
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return (method != (struct objc_method *)0) ? method->method_imp : (IMP)0;
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}
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/* Query if an object can respond to a selector, returns YES if the
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object implements the selector otherwise NO. Does not check if the
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method can be forwarded. Since this requires the dispatch table to
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installed, this function will implicitly invoke +initialize for the
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class of OBJECT if it hasn't been invoked yet. */
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inline
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BOOL
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__objc_responds_to (id object, SEL sel)
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{
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void *res;
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struct sarray *dtable;
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/* Install dispatch table if need be */
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dtable = object->class_pointer->dtable;
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if (dtable == __objc_uninstalled_dtable)
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{
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objc_mutex_lock (__objc_runtime_mutex);
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if (object->class_pointer->dtable == __objc_uninstalled_dtable)
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__objc_install_dtable_for_class (object->class_pointer);
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/* If the dispatch table is not yet installed, we are still in
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the process of executing +initialize. Yet the dispatch table
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should be available. */
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if (object->class_pointer->dtable == __objc_uninstalled_dtable)
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{
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dtable = __objc_prepared_dtable_for_class (object->class_pointer);
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assert (dtable);
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}
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else
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dtable = object->class_pointer->dtable;
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objc_mutex_unlock (__objc_runtime_mutex);
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}
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/* Get the method from the dispatch table. */
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res = sarray_get_safe (dtable, (size_t) sel->sel_id);
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return (res != 0) ? YES : NO;
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}
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BOOL
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class_respondsToSelector (Class class_, SEL selector)
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{
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struct sarray *dtable;
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void *res;
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if (class_ == Nil || selector == NULL)
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return NO;
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/* Install dispatch table if need be. */
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dtable = class_->dtable;
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if (dtable == __objc_uninstalled_dtable)
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{
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objc_mutex_lock (__objc_runtime_mutex);
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if (class_->dtable == __objc_uninstalled_dtable)
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__objc_install_dtable_for_class (class_);
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/* If the dispatch table is not yet installed,
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we are still in the process of executing +initialize.
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Yet the dispatch table should be available. */
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if (class_->dtable == __objc_uninstalled_dtable)
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{
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dtable = __objc_prepared_dtable_for_class (class_);
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assert (dtable);
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}
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else
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dtable = class_->dtable;
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objc_mutex_unlock (__objc_runtime_mutex);
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}
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/* Get the method from the dispatch table. */
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res = sarray_get_safe (dtable, (size_t) selector->sel_id);
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return (res != 0) ? YES : NO;
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}
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/* This is the lookup function. All entries in the table are either a
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valid method *or* zero. If zero then either the dispatch table
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needs to be installed or it doesn't exist and forwarding is
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attempted. */
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IMP
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objc_msg_lookup (id receiver, SEL op)
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{
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IMP result;
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if (receiver)
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{
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/* First try a quick lookup assuming the dispatch table exists. */
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result = sarray_get_safe (receiver->class_pointer->dtable,
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(sidx)op->sel_id);
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if (result == 0)
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{
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/* Not found ... call get_implementation () to install the
|
|
dispatch table and call +initialize as required,
|
|
providing the method implementation or a forwarding
|
|
function. */
|
|
result = get_implementation (receiver, receiver->class_pointer, op);
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|
}
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|
return result;
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}
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else
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return (IMP)nil_method;
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|
}
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IMP
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objc_msg_lookup_super (struct objc_super *super, SEL sel)
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|
{
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if (super->self)
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return get_imp (super->super_class, sel);
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else
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return (IMP)nil_method;
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}
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|
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void
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__objc_init_dispatch_tables ()
|
|
{
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|
__objc_uninstalled_dtable = sarray_new (200, 0);
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|
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/* TODO: It would be cool to register typed selectors here. */
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selector_resolveClassMethod = sel_registerName ("resolveClassMethod:");
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selector_resolveInstanceMethod = sel_registerName ("resolveInstanceMethod:");
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}
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|
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|
|
/* Install dummy table for class which causes the first message to
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|
that class (or instances hereof) to be initialized properly. */
|
|
void
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__objc_install_premature_dtable (Class class)
|
|
{
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assert (__objc_uninstalled_dtable);
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|
class->dtable = __objc_uninstalled_dtable;
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|
}
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|
|
/* Send +initialize to class if not already done. */
|
|
static void
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__objc_send_initialize (Class class)
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|
{
|
|
/* This *must* be a class object. */
|
|
assert (CLS_ISCLASS (class));
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|
assert (! CLS_ISMETA (class));
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|
|
/* class_add_method_list/__objc_update_dispatch_table_for_class may
|
|
have reset the dispatch table. The canonical way to insure that
|
|
we send +initialize just once, is this flag. */
|
|
if (! CLS_ISINITIALIZED (class))
|
|
{
|
|
DEBUG_PRINTF ("+initialize: need to initialize class '%s'\n", class->name);
|
|
CLS_SETINITIALIZED (class);
|
|
CLS_SETINITIALIZED (class->class_pointer);
|
|
|
|
/* Create the garbage collector type memory description. */
|
|
__objc_generate_gc_type_description (class);
|
|
|
|
if (class->super_class)
|
|
__objc_send_initialize (class->super_class);
|
|
|
|
{
|
|
SEL op = sel_registerName ("initialize");
|
|
struct objc_method *method = search_for_method_in_hierarchy (class->class_pointer,
|
|
op);
|
|
|
|
if (method)
|
|
{
|
|
DEBUG_PRINTF (" begin of [%s +initialize]\n", class->name);
|
|
(*method->method_imp) ((id)class, op);
|
|
DEBUG_PRINTF (" end of [%s +initialize]\n", class->name);
|
|
}
|
|
#ifdef DEBUG
|
|
else
|
|
{
|
|
DEBUG_PRINTF (" class '%s' has no +initialize method\n", class->name);
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Walk on the methods list of class and install the methods in the
|
|
reverse order of the lists. Since methods added by categories are
|
|
before the methods of class in the methods list, this allows
|
|
categories to substitute methods declared in class. However if
|
|
more than one category replaces the same method nothing is
|
|
guaranteed about what method will be used. Assumes that
|
|
__objc_runtime_mutex is locked down. */
|
|
static void
|
|
__objc_install_methods_in_dtable (struct sarray *dtable, struct objc_method_list * method_list)
|
|
{
|
|
int i;
|
|
|
|
if (! method_list)
|
|
return;
|
|
|
|
if (method_list->method_next)
|
|
__objc_install_methods_in_dtable (dtable, method_list->method_next);
|
|
|
|
for (i = 0; i < method_list->method_count; i++)
|
|
{
|
|
struct objc_method * method = &(method_list->method_list[i]);
|
|
sarray_at_put_safe (dtable,
|
|
(sidx) method->method_name->sel_id,
|
|
method->method_imp);
|
|
}
|
|
}
|
|
|
|
void
|
|
__objc_update_dispatch_table_for_class (Class class)
|
|
{
|
|
Class next;
|
|
struct sarray *arr;
|
|
|
|
DEBUG_PRINTF (" _objc_update_dtable_for_class (%s)\n", class->name);
|
|
|
|
objc_mutex_lock (__objc_runtime_mutex);
|
|
|
|
/* Not yet installed -- skip it unless in +initialize. */
|
|
if (class->dtable == __objc_uninstalled_dtable)
|
|
{
|
|
if (__objc_prepared_dtable_for_class (class))
|
|
{
|
|
/* There is a prepared table so we must be initialising this
|
|
class ... we must re-do the table preparation. */
|
|
__objc_prepare_dtable_for_class (class);
|
|
}
|
|
objc_mutex_unlock (__objc_runtime_mutex);
|
|
return;
|
|
}
|
|
|
|
arr = class->dtable;
|
|
__objc_install_premature_dtable (class); /* someone might require it... */
|
|
sarray_free (arr); /* release memory */
|
|
|
|
/* Could have been lazy... */
|
|
__objc_install_dtable_for_class (class);
|
|
|
|
if (class->subclass_list) /* Traverse subclasses. */
|
|
for (next = class->subclass_list; next; next = next->sibling_class)
|
|
__objc_update_dispatch_table_for_class (next);
|
|
|
|
objc_mutex_unlock (__objc_runtime_mutex);
|
|
}
|
|
|
|
/* This function adds a method list to a class. This function is
|
|
typically called by another function specific to the run-time. As
|
|
such this function does not worry about thread safe issues.
|
|
|
|
This one is only called for categories. Class objects have their
|
|
methods installed right away, and their selectors are made into
|
|
SEL's by the function __objc_register_selectors_from_class. */
|
|
void
|
|
class_add_method_list (Class class, struct objc_method_list * list)
|
|
{
|
|
/* Passing of a linked list is not allowed. Do multiple calls. */
|
|
assert (! list->method_next);
|
|
|
|
__objc_register_selectors_from_list(list);
|
|
|
|
/* Add the methods to the class's method list. */
|
|
list->method_next = class->methods;
|
|
class->methods = list;
|
|
|
|
/* Update the dispatch table of class. */
|
|
__objc_update_dispatch_table_for_class (class);
|
|
}
|
|
|
|
struct objc_method *
|
|
class_getInstanceMethod (Class class_, SEL selector)
|
|
{
|
|
struct objc_method *m;
|
|
|
|
if (class_ == Nil || selector == NULL)
|
|
return NULL;
|
|
|
|
m = search_for_method_in_hierarchy (class_, selector);
|
|
if (m)
|
|
return m;
|
|
|
|
/* Try going through +resolveInstanceMethod:, and do the search
|
|
again if successful. */
|
|
if (__objc_resolve_instance_method (class_, selector))
|
|
return search_for_method_in_hierarchy (class_, selector);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
struct objc_method *
|
|
class_getClassMethod (Class class_, SEL selector)
|
|
{
|
|
struct objc_method *m;
|
|
|
|
if (class_ == Nil || selector == NULL)
|
|
return NULL;
|
|
|
|
m = search_for_method_in_hierarchy (class_->class_pointer,
|
|
selector);
|
|
if (m)
|
|
return m;
|
|
|
|
/* Try going through +resolveClassMethod:, and do the search again
|
|
if successful. */
|
|
if (__objc_resolve_class_method (class_, selector))
|
|
return search_for_method_in_hierarchy (class_->class_pointer,
|
|
selector);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
BOOL
|
|
class_addMethod (Class class_, SEL selector, IMP implementation,
|
|
const char *method_types)
|
|
{
|
|
struct objc_method_list *method_list;
|
|
struct objc_method *method;
|
|
const char *method_name;
|
|
|
|
if (class_ == Nil || selector == NULL || implementation == NULL
|
|
|| method_types == NULL || (strcmp (method_types, "") == 0))
|
|
return NO;
|
|
|
|
method_name = sel_getName (selector);
|
|
if (method_name == NULL)
|
|
return NO;
|
|
|
|
/* If the method already exists in the class, return NO. It is fine
|
|
if the method already exists in the superclass; in that case, we
|
|
are overriding it. */
|
|
if (CLS_IS_IN_CONSTRUCTION (class_))
|
|
{
|
|
/* The class only contains a list of methods; they have not been
|
|
registered yet, ie, the method_name of each of them is still
|
|
a string, not a selector. Iterate manually over them to
|
|
check if we have already added the method. */
|
|
struct objc_method_list * method_list = class_->methods;
|
|
while (method_list)
|
|
{
|
|
int i;
|
|
|
|
/* Search the method list. */
|
|
for (i = 0; i < method_list->method_count; ++i)
|
|
{
|
|
struct objc_method * method = &method_list->method_list[i];
|
|
|
|
if (method->method_name
|
|
&& strcmp ((char *)method->method_name, method_name) == 0)
|
|
return NO;
|
|
}
|
|
|
|
/* The method wasn't found. Follow the link to the next list of
|
|
methods. */
|
|
method_list = method_list->method_next;
|
|
}
|
|
/* The method wasn't found. It's a new one. Go ahead and add
|
|
it. */
|
|
}
|
|
else
|
|
{
|
|
/* Do the standard lookup. This assumes the selectors are
|
|
mapped. */
|
|
if (search_for_method_in_list (class_->methods, selector))
|
|
return NO;
|
|
}
|
|
|
|
method_list = (struct objc_method_list *)objc_calloc (1, sizeof (struct objc_method_list));
|
|
method_list->method_count = 1;
|
|
|
|
method = &(method_list->method_list[0]);
|
|
method->method_name = objc_malloc (strlen (method_name) + 1);
|
|
strcpy ((char *)method->method_name, method_name);
|
|
|
|
method->method_types = objc_malloc (strlen (method_types) + 1);
|
|
strcpy ((char *)method->method_types, method_types);
|
|
|
|
method->method_imp = implementation;
|
|
|
|
if (CLS_IS_IN_CONSTRUCTION (class_))
|
|
{
|
|
/* We only need to add the method to the list. It will be
|
|
registered with the runtime when the class pair is registered
|
|
(if ever). */
|
|
method_list->method_next = class_->methods;
|
|
class_->methods = method_list;
|
|
}
|
|
else
|
|
{
|
|
/* Add the method to a live class. */
|
|
objc_mutex_lock (__objc_runtime_mutex);
|
|
class_add_method_list (class_, method_list);
|
|
objc_mutex_unlock (__objc_runtime_mutex);
|
|
}
|
|
|
|
return YES;
|
|
}
|
|
|
|
IMP
|
|
class_replaceMethod (Class class_, SEL selector, IMP implementation,
|
|
const char *method_types)
|
|
{
|
|
struct objc_method * method;
|
|
|
|
if (class_ == Nil || selector == NULL || implementation == NULL
|
|
|| method_types == NULL)
|
|
return NULL;
|
|
|
|
method = search_for_method_in_hierarchy (class_, selector);
|
|
|
|
if (method)
|
|
{
|
|
return method_setImplementation (method, implementation);
|
|
}
|
|
else
|
|
{
|
|
class_addMethod (class_, selector, implementation, method_types);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/* Search for a method starting from the current class up its
|
|
hierarchy. Return a pointer to the method's method structure if
|
|
found. NULL otherwise. */
|
|
static struct objc_method *
|
|
search_for_method_in_hierarchy (Class cls, SEL sel)
|
|
{
|
|
struct objc_method * method = NULL;
|
|
Class class;
|
|
|
|
if (! sel_is_mapped (sel))
|
|
return NULL;
|
|
|
|
/* Scan the method list of the class. If the method isn't found in
|
|
the list then step to its super class. */
|
|
for (class = cls; ((! method) && class); class = class->super_class)
|
|
method = search_for_method_in_list (class->methods, sel);
|
|
|
|
return method;
|
|
}
|
|
|
|
|
|
|
|
/* Given a linked list of method and a method's name. Search for the
|
|
named method's method structure. Return a pointer to the method's
|
|
method structure if found. NULL otherwise. */
|
|
struct objc_method *
|
|
search_for_method_in_list (struct objc_method_list * list, SEL op)
|
|
{
|
|
struct objc_method_list * method_list = list;
|
|
|
|
if (! sel_is_mapped (op))
|
|
return NULL;
|
|
|
|
/* If not found then we'll search the list. */
|
|
while (method_list)
|
|
{
|
|
int i;
|
|
|
|
/* Search the method list. */
|
|
for (i = 0; i < method_list->method_count; ++i)
|
|
{
|
|
struct objc_method * method = &method_list->method_list[i];
|
|
|
|
if (method->method_name)
|
|
if (method->method_name->sel_id == op->sel_id)
|
|
return method;
|
|
}
|
|
|
|
/* The method wasn't found. Follow the link to the next list of
|
|
methods. */
|
|
method_list = method_list->method_next;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
typedef void * retval_t;
|
|
typedef void * arglist_t;
|
|
|
|
static retval_t __objc_forward (id object, SEL sel, arglist_t args);
|
|
|
|
/* Forwarding pointers/integers through the normal registers. */
|
|
static id
|
|
__objc_word_forward (id rcv, SEL op, ...)
|
|
{
|
|
void *args, *res;
|
|
|
|
args = __builtin_apply_args ();
|
|
res = __objc_forward (rcv, op, args);
|
|
if (res)
|
|
__builtin_return (res);
|
|
else
|
|
return res;
|
|
}
|
|
|
|
/* Specific routine for forwarding floats/double because of
|
|
architectural differences on some processors. i386s for example
|
|
which uses a floating point stack versus general registers for
|
|
floating point numbers. This forward routine makes sure that GCC
|
|
restores the proper return values. */
|
|
static double
|
|
__objc_double_forward (id rcv, SEL op, ...)
|
|
{
|
|
void *args, *res;
|
|
|
|
args = __builtin_apply_args ();
|
|
res = __objc_forward (rcv, op, args);
|
|
__builtin_return (res);
|
|
}
|
|
|
|
#if INVISIBLE_STRUCT_RETURN
|
|
static __big
|
|
#else
|
|
static id
|
|
#endif
|
|
__objc_block_forward (id rcv, SEL op, ...)
|
|
{
|
|
void *args, *res;
|
|
|
|
args = __builtin_apply_args ();
|
|
res = __objc_forward (rcv, op, args);
|
|
if (res)
|
|
__builtin_return (res);
|
|
else
|
|
#if INVISIBLE_STRUCT_RETURN
|
|
return (__big) {{0, 0, 0, 0, 0, 0, 0, 0}};
|
|
#else
|
|
return nil;
|
|
#endif
|
|
}
|
|
|
|
|
|
/* This function is called for methods which are not implemented,
|
|
unless a custom forwarding routine has been installed. Please note
|
|
that most serious users of libobjc (eg, GNUstep base) do install
|
|
their own forwarding routines, and hence this is never actually
|
|
used. But, if no custom forwarding routine is installed, this is
|
|
called when a selector is not recognized. */
|
|
static retval_t
|
|
__objc_forward (id object, SEL sel, arglist_t args)
|
|
{
|
|
IMP imp;
|
|
static SEL frwd_sel = 0; /* !T:SAFE2 */
|
|
SEL err_sel;
|
|
|
|
/* First try if the object understands forward::. */
|
|
if (! frwd_sel)
|
|
frwd_sel = sel_get_any_uid ("forward::");
|
|
|
|
if (__objc_responds_to (object, frwd_sel))
|
|
{
|
|
imp = get_implementation (object, object->class_pointer, frwd_sel);
|
|
return (*imp) (object, frwd_sel, sel, args);
|
|
}
|
|
|
|
/* If the object recognizes the doesNotRecognize: method then we're
|
|
going to send it. */
|
|
err_sel = sel_get_any_uid ("doesNotRecognize:");
|
|
if (__objc_responds_to (object, err_sel))
|
|
{
|
|
imp = get_implementation (object, object->class_pointer, err_sel);
|
|
return (*imp) (object, err_sel, sel);
|
|
}
|
|
|
|
/* The object doesn't recognize the method. Check for responding to
|
|
error:. If it does then sent it. */
|
|
{
|
|
char msg[256 + strlen ((const char *) sel_getName (sel))
|
|
+ strlen ((const char *) object->class_pointer->name)];
|
|
|
|
sprintf (msg, "(%s) %s does not recognize %s",
|
|
(CLS_ISMETA (object->class_pointer)
|
|
? "class"
|
|
: "instance" ),
|
|
object->class_pointer->name, sel_getName (sel));
|
|
|
|
/* The object doesn't respond to doesNotRecognize:. Therefore, a
|
|
default action is taken. */
|
|
_objc_abort ("%s\n", msg);
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
void
|
|
__objc_print_dtable_stats (void)
|
|
{
|
|
int total = 0;
|
|
|
|
objc_mutex_lock (__objc_runtime_mutex);
|
|
|
|
#ifdef OBJC_SPARSE2
|
|
printf ("memory usage: (%s)\n", "2-level sparse arrays");
|
|
#else
|
|
printf ("memory usage: (%s)\n", "3-level sparse arrays");
|
|
#endif
|
|
|
|
printf ("arrays: %d = %ld bytes\n", narrays,
|
|
(long) ((size_t) narrays * sizeof (struct sarray)));
|
|
total += narrays * sizeof (struct sarray);
|
|
printf ("buckets: %d = %ld bytes\n", nbuckets,
|
|
(long) ((size_t) nbuckets * sizeof (struct sbucket)));
|
|
total += nbuckets * sizeof (struct sbucket);
|
|
|
|
printf ("idxtables: %d = %ld bytes\n",
|
|
idxsize, (long) ((size_t) idxsize * sizeof (void *)));
|
|
total += idxsize * sizeof (void *);
|
|
printf ("-----------------------------------\n");
|
|
printf ("total: %d bytes\n", total);
|
|
printf ("===================================\n");
|
|
|
|
objc_mutex_unlock (__objc_runtime_mutex);
|
|
}
|
|
|
|
static cache_ptr prepared_dtable_table = 0;
|
|
|
|
/* This function is called by: objc_msg_lookup, get_imp and
|
|
__objc_responds_to (and the dispatch table installation functions
|
|
themselves) to install a dispatch table for a class.
|
|
|
|
If CLS is a class, it installs instance methods.
|
|
If CLS is a meta class, it installs class methods.
|
|
|
|
In either case +initialize is invoked for the corresponding class.
|
|
|
|
The implementation must insure that the dispatch table is not
|
|
installed until +initialize completes. Otherwise it opens a
|
|
potential race since the installation of the dispatch table is used
|
|
as gate in regular method dispatch and we need to guarantee that
|
|
+initialize is the first method invoked an that no other thread my
|
|
dispatch messages to the class before +initialize completes. */
|
|
static void
|
|
__objc_install_dtable_for_class (Class cls)
|
|
{
|
|
/* If the class has not yet had its class links resolved, we must
|
|
re-compute all class links. */
|
|
if (! CLS_ISRESOLV (cls))
|
|
__objc_resolve_class_links ();
|
|
|
|
/* Make sure the super class has its dispatch table installed or is
|
|
at least preparing. We do not need to send initialize for the
|
|
super class since __objc_send_initialize will insure that. */
|
|
if (cls->super_class
|
|
&& cls->super_class->dtable == __objc_uninstalled_dtable
|
|
&& !__objc_prepared_dtable_for_class (cls->super_class))
|
|
{
|
|
__objc_install_dtable_for_class (cls->super_class);
|
|
/* The superclass initialisation may have also initialised the
|
|
current class, in which case there is no more to do. */
|
|
if (cls->dtable != __objc_uninstalled_dtable)
|
|
return;
|
|
}
|
|
|
|
/* We have already been prepared but +initialize hasn't completed.
|
|
The +initialize implementation is probably sending 'self'
|
|
messages. We rely on _objc_get_prepared_imp to retrieve the
|
|
implementation pointers. */
|
|
if (__objc_prepared_dtable_for_class (cls))
|
|
return;
|
|
|
|
/* We have this function cache the implementation pointers for
|
|
_objc_get_prepared_imp but the dispatch table won't be initilized
|
|
until __objc_send_initialize completes. */
|
|
__objc_prepare_dtable_for_class (cls);
|
|
|
|
/* We may have already invoked +initialize but
|
|
__objc_update_dispatch_table_for_class invoked by
|
|
class_add_method_list may have reset dispatch table. */
|
|
|
|
/* Call +initialize. If we are a real class, we are installing
|
|
instance methods. If we are a meta class, we are installing
|
|
class methods. The __objc_send_initialize itself will insure
|
|
that the message is called only once per class. */
|
|
if (CLS_ISCLASS (cls))
|
|
__objc_send_initialize (cls);
|
|
else
|
|
{
|
|
/* Retrieve the class from the meta class. */
|
|
Class c = objc_getClass (cls->name);
|
|
assert (CLS_ISMETA (cls));
|
|
assert (c);
|
|
__objc_send_initialize (c);
|
|
}
|
|
|
|
/* We install the dispatch table correctly when +initialize completed. */
|
|
__objc_install_prepared_dtable_for_class (cls);
|
|
}
|
|
|
|
/* Builds the dispatch table for the class CLS and stores it in a
|
|
place where it can be retrieved by __objc_get_prepared_imp until
|
|
__objc_install_prepared_dtable_for_class installs it into the
|
|
class. The dispatch table should not be installed into the class
|
|
until +initialize has completed. */
|
|
static void
|
|
__objc_prepare_dtable_for_class (Class cls)
|
|
{
|
|
struct sarray *dtable;
|
|
struct sarray *super_dtable;
|
|
|
|
/* This table could be initialized in init.c. We can not use the
|
|
class name since the class maintains the instance methods and the
|
|
meta class maintains the the class methods yet both share the
|
|
same name. Classes should be unique in any program. */
|
|
if (! prepared_dtable_table)
|
|
prepared_dtable_table
|
|
= objc_hash_new (32,
|
|
(hash_func_type) objc_hash_ptr,
|
|
(compare_func_type) objc_compare_ptrs);
|
|
|
|
/* If the class has not yet had its class links resolved, we must
|
|
re-compute all class links. */
|
|
if (! CLS_ISRESOLV (cls))
|
|
__objc_resolve_class_links ();
|
|
|
|
assert (cls);
|
|
assert (cls->dtable == __objc_uninstalled_dtable);
|
|
|
|
/* If there is already a prepared dtable for this class, we must
|
|
replace it with a new version (since there must have been methods
|
|
added to or otherwise modified in the class while executing
|
|
+initialize, and the table needs to be recomputed. */
|
|
dtable = __objc_prepared_dtable_for_class (cls);
|
|
if (dtable != 0)
|
|
{
|
|
objc_hash_remove (prepared_dtable_table, cls);
|
|
sarray_free (dtable);
|
|
}
|
|
|
|
/* Now prepare the dtable for population. */
|
|
assert (cls != cls->super_class);
|
|
if (cls->super_class)
|
|
{
|
|
/* Inherit the method list from the super class. Yet the super
|
|
class may still be initializing in the case when a class
|
|
cluster sub class initializes its super classes. */
|
|
if (cls->super_class->dtable == __objc_uninstalled_dtable)
|
|
__objc_install_dtable_for_class (cls->super_class);
|
|
|
|
super_dtable = cls->super_class->dtable;
|
|
/* If the dispatch table is not yet installed, we are still in
|
|
the process of executing +initialize. Yet the dispatch table
|
|
should be available. */
|
|
if (super_dtable == __objc_uninstalled_dtable)
|
|
super_dtable = __objc_prepared_dtable_for_class (cls->super_class);
|
|
|
|
assert (super_dtable);
|
|
dtable = sarray_lazy_copy (super_dtable);
|
|
}
|
|
else
|
|
dtable = sarray_new (__objc_selector_max_index, 0);
|
|
|
|
__objc_install_methods_in_dtable (dtable, cls->methods);
|
|
|
|
objc_hash_add (&prepared_dtable_table,
|
|
cls,
|
|
dtable);
|
|
}
|
|
|
|
/* This wrapper only exists to allow an easy replacement of the lookup
|
|
implementation and it is expected that the compiler will optimize
|
|
it away. */
|
|
static struct sarray *
|
|
__objc_prepared_dtable_for_class (Class cls)
|
|
{
|
|
struct sarray *dtable = 0;
|
|
assert (cls);
|
|
if (prepared_dtable_table)
|
|
dtable = objc_hash_value_for_key (prepared_dtable_table, cls);
|
|
/* dtable my be nil, since we call this to check whether we are
|
|
currently preparing before we start preparing. */
|
|
return dtable;
|
|
}
|
|
|
|
/* Helper function for messages sent to CLS or implementation pointers
|
|
retrieved from CLS during +initialize before the dtable is
|
|
installed. When a class implicitly initializes another class which
|
|
in turn implicitly invokes methods in this class, before the
|
|
implementation of +initialize of CLS completes, this returns the
|
|
expected implementation. Forwarding remains the responsibility of
|
|
objc_msg_lookup. This function should only be called under the
|
|
global lock. */
|
|
static IMP
|
|
__objc_get_prepared_imp (Class cls,SEL sel)
|
|
{
|
|
struct sarray *dtable;
|
|
IMP imp;
|
|
|
|
assert (cls);
|
|
assert (sel);
|
|
assert (cls->dtable == __objc_uninstalled_dtable);
|
|
dtable = __objc_prepared_dtable_for_class (cls);
|
|
|
|
assert (dtable);
|
|
assert (dtable != __objc_uninstalled_dtable);
|
|
imp = sarray_get_safe (dtable, (size_t) sel->sel_id);
|
|
|
|
/* imp may be Nil if the method does not exist and we may fallback
|
|
to the forwarding implementation later. */
|
|
return imp;
|
|
}
|
|
|
|
/* When this function is called +initialize should be completed. So
|
|
now we are safe to install the dispatch table for the class so that
|
|
they become available for other threads that may be waiting in the
|
|
lock. */
|
|
static void
|
|
__objc_install_prepared_dtable_for_class (Class cls)
|
|
{
|
|
assert (cls);
|
|
assert (cls->dtable == __objc_uninstalled_dtable);
|
|
cls->dtable = __objc_prepared_dtable_for_class (cls);
|
|
|
|
assert (cls->dtable);
|
|
assert (cls->dtable != __objc_uninstalled_dtable);
|
|
objc_hash_remove (prepared_dtable_table, cls);
|
|
}
|