649 lines
18 KiB
C
649 lines
18 KiB
C
/* GNU Objective C Runtime message lookup
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Copyright (C) 1993, 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
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Contributed by Kresten Krab Thorup
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This file is part of GNU CC.
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GNU CC 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 2, or (at your option) any later version.
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GNU CC 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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You should have received a copy of the GNU General Public License along with
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GNU CC; see the file COPYING. If not, write to the Free Software
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Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* As a special exception, if you link this library with files compiled with
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GCC to produce an executable, this does not cause the resulting executable
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to be covered by the GNU General Public License. This exception does not
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however invalidate any other reasons why the executable file might be
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covered by the GNU General Public License. */
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#include "tconfig.h"
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#include "runtime.h"
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#include "sarray.h"
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#include "encoding.h"
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#include "runtime-info.h"
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/* this is how we hack STRUCT_VALUE to be 1 or 0 */
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#define gen_rtx(args...) 1
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#define gen_rtx_MEM(args...) 1
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#define rtx int
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#if !defined(STRUCT_VALUE) || STRUCT_VALUE == 0
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#define INVISIBLE_STRUCT_RETURN 1
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#else
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#define INVISIBLE_STRUCT_RETURN 0
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#endif
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/* The uninstalled dispatch table */
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struct sarray* __objc_uninstalled_dtable = 0; /* !T:MUTEX */
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/* Send +initialize to class */
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static void __objc_send_initialize(Class);
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static void __objc_install_dispatch_table_for_class (Class);
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/* Forward declare some functions */
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static void __objc_init_install_dtable(id, 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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*/
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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 Method_t search_for_method_in_hierarchy (Class class, SEL sel);
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Method_t search_for_method_in_list(MethodList_t list, SEL op);
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id nil_method(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 (SEL sel)
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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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/* Given a class and selector, return the selector's implementation. */
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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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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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/* Not a valid method */
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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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__objc_install_dispatch_table_for_class (class);
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objc_mutex_unlock(__objc_runtime_mutex);
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/* Call ourselves with the installed dispatch table
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and get the real method */
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res = get_imp(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 so the
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method just doesn't exist for the class.
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Return the forwarding implementation. */
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res = __objc_get_forward_imp(sel);
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}
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}
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return res;
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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. */
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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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/* Install dispatch table if need be */
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if (object->class_pointer->dtable == __objc_uninstalled_dtable)
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{
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objc_mutex_lock(__objc_runtime_mutex);
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__objc_install_dispatch_table_for_class (object->class_pointer);
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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 (object->class_pointer->dtable, (size_t) sel->sel_id);
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return (res != 0);
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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 attempted. */
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__inline__
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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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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 a valid method */
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if(receiver->class_pointer->dtable == __objc_uninstalled_dtable)
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{
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/* The dispatch table needs to be installed.
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This happens on the very first method call to the class. */
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__objc_init_install_dtable(receiver, op);
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/* Get real method for this in newly installed dtable */
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result = get_imp(receiver->class_pointer, op);
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}
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else
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{
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/* The dispatch table has been installed so the
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method just doesn't exist for the class.
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Attempt to forward the method. */
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result = __objc_get_forward_imp(op);
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}
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}
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return result;
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}
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else
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return nil_method;
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}
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IMP
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objc_msg_lookup_super (Super_t super, SEL sel)
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{
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if (super->self)
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return get_imp (super->class, sel);
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else
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return nil_method;
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}
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int method_get_sizeof_arguments (Method*);
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retval_t
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objc_msg_sendv(id object, SEL op, arglist_t arg_frame)
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{
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Method* m = class_get_instance_method(object->class_pointer, op);
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const char *type;
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*((id*)method_get_first_argument (m, arg_frame, &type)) = object;
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*((SEL*)method_get_next_argument (arg_frame, &type)) = op;
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return __builtin_apply((apply_t)m->method_imp,
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arg_frame,
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method_get_sizeof_arguments (m));
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}
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void
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__objc_init_dispatch_tables()
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{
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__objc_uninstalled_dtable
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= sarray_new(200, 0);
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}
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/* This function is called by objc_msg_lookup when the
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dispatch table needs to be installed; thus it is called once
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for each class, namely when the very first message is sent to it. */
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static void
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__objc_init_install_dtable(id receiver, SEL op)
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{
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/* This may happen, if the programmer has taken the address of a
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method before the dtable was initialized... too bad for him! */
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if(receiver->class_pointer->dtable != __objc_uninstalled_dtable)
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return;
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objc_mutex_lock(__objc_runtime_mutex);
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if(CLS_ISCLASS(receiver->class_pointer))
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{
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/* receiver is an ordinary object */
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assert(CLS_ISCLASS(receiver->class_pointer));
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/* install instance methods table */
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__objc_install_dispatch_table_for_class (receiver->class_pointer);
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/* call +initialize -- this will in turn install the factory
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dispatch table if not already done :-) */
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__objc_send_initialize(receiver->class_pointer);
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}
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else
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{
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/* receiver is a class object */
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assert(CLS_ISCLASS((Class)receiver));
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assert(CLS_ISMETA(receiver->class_pointer));
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/* Install real dtable for factory methods */
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__objc_install_dispatch_table_for_class (receiver->class_pointer);
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__objc_send_initialize((Class)receiver);
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}
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objc_mutex_unlock(__objc_runtime_mutex);
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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 */
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void
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__objc_install_premature_dtable(Class class)
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{
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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 */
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static void
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__objc_send_initialize(Class class)
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{
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/* This *must* be a class object */
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assert(CLS_ISCLASS(class));
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assert(!CLS_ISMETA(class));
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if (!CLS_ISINITIALIZED(class))
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{
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CLS_SETINITIALIZED(class);
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CLS_SETINITIALIZED(class->class_pointer);
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/* Create the garbage collector type memory description */
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__objc_generate_gc_type_description (class);
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if(class->super_class)
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__objc_send_initialize(class->super_class);
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{
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SEL op = sel_register_name ("initialize");
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IMP imp = 0;
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MethodList_t method_list = class->class_pointer->methods;
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while (method_list) {
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int i;
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Method_t method;
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for (i = 0; i< method_list->method_count; i++) {
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method = &(method_list->method_list[i]);
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if (method->method_name
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&& method->method_name->sel_id == op->sel_id) {
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imp = method->method_imp;
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break;
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}
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}
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if (imp)
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break;
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method_list = method_list->method_next;
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}
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if (imp)
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(*imp)((id)class, op);
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}
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}
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}
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/* Walk on the methods list of class and install the methods in the reverse
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order of the lists. Since methods added by categories are before the methods
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of class in the methods list, this allows categories to substitute methods
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declared in class. However if more than one category replaces the same
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method nothing is guaranteed about what method will be used.
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Assumes that __objc_runtime_mutex is locked down. */
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static void
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__objc_install_methods_in_dtable (Class class, MethodList_t method_list)
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{
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int i;
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if (!method_list)
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return;
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if (method_list->method_next)
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__objc_install_methods_in_dtable (class, method_list->method_next);
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for (i = 0; i < method_list->method_count; i++)
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{
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Method_t method = &(method_list->method_list[i]);
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sarray_at_put_safe (class->dtable,
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(sidx) method->method_name->sel_id,
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method->method_imp);
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}
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}
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/* Assumes that __objc_runtime_mutex is locked down. */
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static void
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__objc_install_dispatch_table_for_class (Class class)
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{
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Class super;
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/* If the class has not yet had its class links resolved, we must
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re-compute all class links */
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if(!CLS_ISRESOLV(class))
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__objc_resolve_class_links();
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super = class->super_class;
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if (super != 0 && (super->dtable == __objc_uninstalled_dtable))
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__objc_install_dispatch_table_for_class (super);
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/* Allocate dtable if necessary */
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if (super == 0)
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{
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objc_mutex_lock(__objc_runtime_mutex);
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class->dtable = sarray_new (__objc_selector_max_index, 0);
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objc_mutex_unlock(__objc_runtime_mutex);
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}
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else
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class->dtable = sarray_lazy_copy (super->dtable);
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__objc_install_methods_in_dtable (class, class->methods);
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}
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void
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__objc_update_dispatch_table_for_class (Class class)
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{
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Class next;
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struct sarray *arr;
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/* not yet installed -- skip it */
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if (class->dtable == __objc_uninstalled_dtable)
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return;
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objc_mutex_lock(__objc_runtime_mutex);
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arr = class->dtable;
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__objc_install_premature_dtable (class); /* someone might require it... */
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sarray_free (arr); /* release memory */
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/* could have been lazy... */
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__objc_install_dispatch_table_for_class (class);
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if (class->subclass_list) /* Traverse subclasses */
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for (next = class->subclass_list; next; next = next->sibling_class)
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__objc_update_dispatch_table_for_class (next);
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objc_mutex_unlock(__objc_runtime_mutex);
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}
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/* This function adds a method list to a class. This function is
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typically called by another function specific to the run-time. As
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such this function does not worry about thread safe issues.
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This one is only called for categories. Class objects have their
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methods installed right away, and their selectors are made into
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SEL's by the function __objc_register_selectors_from_class. */
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void
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class_add_method_list (Class class, MethodList_t list)
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{
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int i;
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/* Passing of a linked list is not allowed. Do multiple calls. */
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assert (!list->method_next);
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/* Check for duplicates. */
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for (i = 0; i < list->method_count; ++i)
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{
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Method_t method = &list->method_list[i];
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if (method->method_name) /* Sometimes these are NULL */
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{
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/* This is where selector names are transmogrified to SEL's */
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method->method_name =
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sel_register_typed_name ((const char*)method->method_name,
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method->method_types);
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}
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}
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/* Add the methods to the class's method list. */
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list->method_next = class->methods;
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class->methods = list;
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/* Update the dispatch table of class */
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__objc_update_dispatch_table_for_class (class);
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}
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Method_t
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class_get_instance_method(Class class, SEL op)
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{
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return search_for_method_in_hierarchy(class, op);
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}
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Method_t
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class_get_class_method(MetaClass class, SEL op)
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{
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return search_for_method_in_hierarchy(class, op);
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}
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/* Search for a method starting from the current class up its hierarchy.
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Return a pointer to the method's method structure if found. NULL
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otherwise. */
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static Method_t
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search_for_method_in_hierarchy (Class cls, SEL sel)
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{
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Method_t method = NULL;
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Class class;
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if (! sel_is_mapped (sel))
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return NULL;
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/* Scan the method list of the class. If the method isn't found in the
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list then step to its super class. */
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for (class = cls; ((! method) && class); class = class->super_class)
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method = search_for_method_in_list (class->methods, sel);
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return method;
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}
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/* Given a linked list of method and a method's name. Search for the named
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method's method structure. Return a pointer to the method's method
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structure if found. NULL otherwise. */
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Method_t
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search_for_method_in_list (MethodList_t list, SEL op)
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{
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MethodList_t method_list = list;
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if (! sel_is_mapped (op))
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return NULL;
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/* If not found then we'll search the list. */
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while (method_list)
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{
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int i;
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/* Search the method list. */
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for (i = 0; i < method_list->method_count; ++i)
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{
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Method_t method = &method_list->method_list[i];
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if (method->method_name)
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if (method->method_name->sel_id == op->sel_id)
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return method;
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}
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/* The method wasn't found. Follow the link to the next list of
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methods. */
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method_list = method_list->method_next;
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}
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return NULL;
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}
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static retval_t __objc_forward (id object, SEL sel, arglist_t args);
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/* Forwarding pointers/integers through the normal registers */
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static id
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__objc_word_forward (id rcv, SEL op, ...)
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{
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void *args, *res;
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args = __builtin_apply_args ();
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res = __objc_forward (rcv, op, args);
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if (res)
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__builtin_return (res);
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else
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return res;
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}
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/* Specific routine for forwarding floats/double because of
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architectural differences on some processors. i386s for
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example which uses a floating point stack versus general
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registers for floating point numbers. This forward routine
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makes sure that GCC restores the proper return values */
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static double
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__objc_double_forward (id rcv, SEL op, ...)
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{
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void *args, *res;
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args = __builtin_apply_args ();
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res = __objc_forward (rcv, op, args);
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__builtin_return (res);
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}
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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 rcv, SEL op, ...)
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{
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void *args, *res;
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args = __builtin_apply_args ();
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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 installed in the dispatch table for all methods which are
|
|
not implemented. Thus, it 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_imp(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_imp (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. */
|
|
{
|
|
size_t strlen (const char*);
|
|
char msg[256 + strlen ((const char*)sel_get_name (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_get_name (sel));
|
|
|
|
err_sel = sel_get_any_uid ("error:");
|
|
if (__objc_responds_to (object, err_sel))
|
|
{
|
|
imp = get_imp (object->class_pointer, err_sel);
|
|
return (*imp) (object, sel_get_any_uid ("error:"), msg);
|
|
}
|
|
|
|
/* The object doesn't respond to doesNotRecognize: or error:; Therefore,
|
|
a default action is taken. */
|
|
objc_error (object, OBJC_ERR_UNIMPLEMENTED, "%s\n", msg);
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
void
|
|
__objc_print_dtable_stats()
|
|
{
|
|
int total = 0;
|
|
|
|
objc_mutex_lock(__objc_runtime_mutex);
|
|
|
|
printf("memory usage: (%s)\n",
|
|
#ifdef OBJC_SPARSE2
|
|
"2-level sparse arrays"
|
|
#else
|
|
"3-level sparse arrays"
|
|
#endif
|
|
);
|
|
|
|
printf("arrays: %d = %ld bytes\n", narrays,
|
|
(long)narrays*sizeof(struct sarray));
|
|
total += narrays*sizeof(struct sarray);
|
|
printf("buckets: %d = %ld bytes\n", nbuckets,
|
|
(long)nbuckets*sizeof(struct sbucket));
|
|
total += nbuckets*sizeof(struct sbucket);
|
|
|
|
printf("idxtables: %d = %ld bytes\n", idxsize, (long)idxsize*sizeof(void*));
|
|
total += idxsize*sizeof(void*);
|
|
printf("-----------------------------------\n");
|
|
printf("total: %d bytes\n", total);
|
|
printf("===================================\n");
|
|
|
|
objc_mutex_unlock(__objc_runtime_mutex);
|
|
}
|
|
|
|
/* Returns the uninstalled dispatch table indicator.
|
|
If a class' dispatch table points to __objc_uninstalled_dtable
|
|
then that means it needs its dispatch table to be installed. */
|
|
__inline__
|
|
struct sarray*
|
|
objc_get_uninstalled_dtable()
|
|
{
|
|
return __objc_uninstalled_dtable;
|
|
}
|