/* GNU Objective C Runtime message lookup
Copyright (C) 1993 Free Software Foundation, Inc.
Author: Kresten Krab Thorup
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 2, or (at your option) any later version.
GNU CC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
You should have received a copy of the GNU General Public License along with
GNU CC; see the file COPYING. If not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/* As a special exception, if you link this library with files compiled with
GCC to produce an executable, this does not cause the resulting executable
to be covered by the GNU General Public License. This exception does not
however invalidate any other reasons why the executable file might be
covered by the GNU General Public License. */
/* The uninstalled dispatch table */
struct sarray
* __objc_uninstalled_dtable
= 0;
/* Send +initialize to class */
static void __objc_send_initialize(Class
*);
static void __objc_install_dispatch_table_for_class (Class
*);
/* Forward declare some functions */
static void __objc_init_install_dtable(id
, SEL
);
static id
__objc_missing_method(id
, SEL
, ...);
static Method_t
search_for_method_in_hierarchy (Class
* class, SEL sel
);
static Method_t
search_for_method_in_list(MethodList_t list
, SEL op
);
id
nil_method(id
, SEL
, ...);
nil_method(id receiver
, SEL op
, ...)
/* Given a class and selector, return the selector's implementation. */
get_imp (Class
* class, SEL sel
)
void* res
= sarray_get (class->dtable
, (size_t) sel
);
if(res
== __objc_init_install_dtable
)
__objc_install_dispatch_table_for_class (class);
return sarray_get (class->dtable
, (size_t) sel
);
__objc_responds_to (id object
, SEL sel
)
return get_imp (object
->class_pointer
, sel
) != __objc_missing_method
;
/* This is the lookup function. All entries in the table are either a
valid method *or* one of `__objc_missing_method' which calls
forward:: etc, or `__objc_init_install_dtable' which installs the
objc_msg_lookup(id receiver
, SEL op
)
return sarray_get(receiver
->class_pointer
->dtable
, (sidx
)op
);
objc_msg_lookup_super (Super_t super
, SEL sel
)
return get_imp (super
->class, sel
);
objc_msg_sendv(id object
, SEL op
, size_t frame_size
, arglist_t arg_frame
)
#ifdef __objc_frame_receiver
__objc_frame_receiver(arg_frame
) = object
;
__objc_frame_selector(arg_frame
) = op
;
return __builtin_apply((apply_t
)get_imp(object
->class_pointer
, op
),
#warning performv:: will not work
(*_objc_error
)(object
, "objc_msg_sendv (performv::) not supported\n", nothing
);
void __objc_init_dispatch_tables()
__objc_uninstalled_dtable
= sarray_new(200, __objc_init_install_dtable
);
/* This one is a bit hairy. This function is installed in the
premature dispatch table, and thus called once for each class,
namely when the very first message is send to it. */
static void __objc_init_install_dtable(id receiver
, SEL op
)
__label__ allready_initialized
;
/* This may happen, if the programmer has taken the address of a
method before the dtable was initialized... too bad for him! */
if(receiver
->class_pointer
->dtable
!= __objc_uninstalled_dtable
)
goto allready_initialized
;
if(CLS_ISCLASS(receiver
->class_pointer
))
/* receiver is an ordinary object */
assert(CLS_ISCLASS(receiver
->class_pointer
));
/* install instance methods table */
__objc_install_dispatch_table_for_class (receiver
->class_pointer
);
/* call +initialize -- this will in turn install the factory
dispatch table if not already done :-) */
__objc_send_initialize(receiver
->class_pointer
);
/* receiver is a class object */
assert(CLS_ISCLASS((Class
*)receiver
));
assert(CLS_ISMETA(receiver
->class_pointer
));
/* Install real dtable for factory methods */
__objc_install_dispatch_table_for_class (receiver
->class_pointer
);
if(op
!= sel_get_uid ("initialize"))
__objc_send_initialize((Class
*)receiver
);
CLS_SETINITIALIZED((Class
*)receiver
);
/* Get real method for this in newly installed dtable */
imp
= get_imp(receiver
->class_pointer
, op
);
args
= __builtin_apply_args();
result
= __builtin_apply((apply_t
)imp
, args
, 96);
__builtin_return (result
);
/* Install dummy table for class which causes the first message to
that class (or instances hereof) to be initialized properly */
void __objc_install_premature_dtable(Class
* class)
assert(__objc_uninstalled_dtable
);
class->dtable
= __objc_uninstalled_dtable
;
/* Send +initialize to class if not already done */
static void __objc_send_initialize(Class
* class)
/* This *must* be a class object */
assert(CLS_ISCLASS(class));
assert(!CLS_ISMETA(class));
if (!CLS_ISINITIALIZED(class))
CLS_SETINITIALIZED(class);
CLS_SETINITIALIZED(class->class_pointer
);
__objc_send_initialize(class->super_class
);
MethodList_t method_list
= class->class_pointer
->methods
;
SEL op
= sel_register_name ("initialize");
/* If not found then we'll search the list. */
/* Search the method list. */
for (i
= 0; i
< method_list
->method_count
; ++i
)
Method_t method
= &method_list
->method_list
[i
];
if (method
->method_name
== op
)
(*method
->method_imp
)((id
) class, op
);
/* The method wasn't found. Follow the link to the next list of
method_list
= method_list
->method_next
;
__objc_install_dispatch_table_for_class (Class
* class)
/* If the class has not yet had it's class links resolved, we must
re-compute all class links */
__objc_resolve_class_links();
super
= class->super_class
;
if (super
!= 0 && (super
->dtable
== __objc_uninstalled_dtable
))
__objc_install_dispatch_table_for_class (super
);
/* Allocate dtable if nessecary */
class->dtable
= sarray_new (__objc_selector_max_index
,
class->dtable
= sarray_lazy_copy (super
->dtable
);
for (mlist
= class->methods
; mlist
; mlist
= mlist
->method_next
)
counter
= mlist
->method_count
- 1;
Method_t method
= &(mlist
->method_list
[counter
]);
sarray_at_put (class->dtable
,
(sidx
) method
->method_name
,
void __objc_update_dispatch_table_for_class (Class
* class)
/* not yet installed -- skip it */
if (class->dtable
== __objc_uninstalled_dtable
)
__objc_install_premature_dtable (class);
if (class->subclass_list
) /* Traverse subclasses */
for (next
= class->subclass_list
; next
; next
= next
->sibling_class
)
__objc_update_dispatch_table_for_class (next
);
/* 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 issued.
This one is only called for categories. Class objects have their
methods installed rightaway, and their selectors are made into
SEL's by the function __objc_register_selectors_from_class. */
class_add_method_list (Class
* class, MethodList_t list
)
static SEL initialize_sel
= 0;
initialize_sel
= sel_register_name ("initialize");
/* Passing of a linked list is not allowed. Do multiple calls. */
assert (!list
->method_next
);
/* Check for duplicates. */
for (i
= 0; i
< list
->method_count
; ++i
)
Method_t method
= &list
->method_list
[i
];
if (method
->method_name
) /* Sometimes these are NULL */
/* This is where selector names are transmogriffed to SEL's */
method
->method_name
= sel_register_name ((char*)method
->method_name
);
if (search_for_method_in_list (class->methods
, method
->method_name
)
&& method
->method_name
!= initialize_sel
)
/* Duplication. Print a error message an change the method name
fprintf (stderr
, "attempt to add a existing method: %s\n",
sel_get_name(method
->method_name
));
/* Add the methods to the class's method list. */
list
->method_next
= class->methods
;
class_get_instance_method(Class
* class, SEL op
)
return search_for_method_in_hierarchy(class, op
);
class_get_class_method(MetaClass
* class, SEL op
)
return search_for_method_in_hierarchy(class, op
);
/* Search for a method starting from the current class up its hierarchy.
Return a pointer to the method's method structure if found. NULL
search_for_method_in_hierarchy (Class
* cls
, SEL sel
)
if (! sel_is_mapped (sel
))
/* 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
);
/* 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. */
search_for_method_in_list (MethodList_t list
, SEL op
)
MethodList_t method_list
= list
;
if (! sel_is_mapped (op
))
/* If not found then we'll search the list. */
/* Search the method list. */
for (i
= 0; i
< method_list
->method_count
; ++i
)
Method_t method
= &method_list
->method_list
[i
];
if (method
->method_name
== op
)
/* The method wasn't found. Follow the link to the next list of
method_list
= method_list
->method_next
;
/* This fuction is installed in the dispatch table for all methods which are
not implemented. Thus, it is called when a selector is not recognized. */
__objc_missing_method (id object
, SEL sel
, ...)
/* first try if the object understands forward:: */
frwd_sel
= sel_get_uid("forward::");
imp
= get_imp(object
->class_pointer
, frwd_sel
);
if(imp
!= __objc_missing_method
)
void *result
, *args
= __builtin_apply_args();
result
= (*imp
)(object
, frwd_sel
, sel
, args
);
__builtin_return(result
);
/* If the object recognizes the doesNotRecognize: method then we're going
err_sel
= sel_get_uid ("doesNotRecognize:");
imp
= get_imp (object
->class_pointer
, err_sel
);
if (imp
!= __objc_missing_method
)
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 ((char*)sel_get_name (sel
))
+ strlen ((char*)object
->class_pointer
->name
)];
sprintf (msg
, "(%s) %s does not recognize %s",
(CLS_ISMETA(object
->class_pointer
)
object
->class_pointer
->name
, sel_get_name (sel
));
err_sel
= sel_get_uid ("error:");
imp
= get_imp (object
->class_pointer
, err_sel
);
if (imp
!= __objc_missing_method
)
return (*imp
) (object
, sel_get_uid ("error:"), msg
);
/* The object doesn't respond to doesNotRecognize: or error:; Therefore,
a default action is taken. */
fprintf (stderr
, "fatal: %s\n", msg
);
void __objc_print_dtable_stats()
printf("memory usage: (%s)\n",
printf("arrays: %d = %d bytes\n", narrays
, narrays
*sizeof(struct sarray
));
total
+= narrays
*sizeof(struct sarray
);
printf("buckets: %d = %d bytes\n", nbuckets
, nbuckets
*sizeof(struct sbucket
));
total
+= nbuckets
*sizeof(struct sbucket
);
printf("idxtables: %d = %d bytes\n", idxsize
, idxsize
*sizeof(void*));
total
+= idxsize
*sizeof(void*);
printf("-----------------------------------\n");
printf("total: %d bytes\n", total
);
printf("===================================\n");