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/*
dld-load - Definitions and translations for dynamic loading with GNU dld.
Copyright (C) 1995, Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This program 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
BUGS:
- object files loaded by dld must be loaded with 'ld -r' rather
than 'gcc -nostdlib', because dld can't handle multiple symbols
like multiple CTOR_LISTS. So here we construct our own CTOR
list and return it when asked for (Ack! Pthet!).
- __dld_construct_ctor_list may find a constructor that belongs
to another module whose name is a super-string of the desired
module name.
*/
#ifndef __dld_load_h_INCLUDE
#define __dld_load_h_INCLUDE
#include <dld/defs.h>
/* This is the GNU gcc name for the CTOR list */
#define CTOR_LIST "___CTOR_LIST__"
/* The compiler generates a constructor function for each class. The function
has the prefix given below.
*/
#define GLOBAL_PREFIX "_GLOBAL_$I$"
/* Types defined appropriately for the dynamic linker */
typedef char* dl_handle_t;
typedef unsigned long dl_symbol_t;
static void **dld_ctor_list = 0;
static void**
__dld_construct_ctor_list(dl_handle_t module)
{
int i, ctors, length;
length = 100;
ctors = 1;
if (dld_ctor_list)
free(dld_ctor_list);
dld_ctor_list = (void **) __objc_xmalloc(length * sizeof(void *));
/* Find all symbols with the GLOBAL_PREFIX prefix */
for (i=0; i < TABSIZE; i++)
{
struct glosym *sym_entry = _dld_symtab[i];
for (; sym_entry; sym_entry = sym_entry->link)
{
if (strstr(sym_entry->name, GLOBAL_PREFIX)
&& strstr(sym_entry->defined_by->filename, module))
{
dld_ctor_list[ctors] = (void **)sym_entry->value;
ctors++;
if (ctors > length)
{
length *= 2;
dld_ctor_list = (void **) __objc_xrealloc(dld_ctor_list,
length * sizeof(void *));
}
}
}
}
dld_ctor_list[ctors] = (void **)0;
dld_ctor_list[0] = (void **)(ctors - 1);
return dld_ctor_list;
}
/* Do any initialization necessary. Return 0 on success (or
if no initialization needed.
*/
static int
__objc_dynamic_init(const char* exec_path)
{
return dld_init(exec_path);
}
/* Link in the module given by the name 'module'. Return a handle which can
be used to get information about the loded code.
*/
static dl_handle_t
__objc_dynamic_link(const char* module, int mode, const char* debug_file)
{
int error;
int length = strlen(module);
dl_handle_t handle;
error = dld_link(module);
if (error)
return NULL;
handle = (dl_handle_t)__objc_xmalloc (length + 1);
strncpy(handle, module, length);
handle[length] = '\0';
return handle;
}
/* Return the address of a symbol given by the name 'symbol' from the module
* associated with 'handle'
* This function is not always used, so we mark it as unused to avoid warnings.
*/
static dl_symbol_t
__objc_dynamic_find_symbol(dl_handle_t handle, const char* symbol)
__attribute__((unused));
static dl_symbol_t
__objc_dynamic_find_symbol(dl_handle_t handle, const char* symbol)
{
if (strcmp(symbol, DLD_CTOR_LIST) == 0)
{
return (dl_symbol_t)__dld_construct_ctor_list(handle);
}
return dld_get_bare_symbol(symbol);
}
/* remove the code from memory associated with the module 'handle' */
static int
__objc_dynamic_unlink(dl_handle_t handle)
{
int error;
error = dld_unlink_by_file(handle, 0);
free(handle);
return error;
}
/* Print an error message (prefaced by 'error_string') relevant to the
last error encountered
*/
static void
__objc_dynamic_error(FILE *error_stream, const char *error_string)
{
/* dld won't print to error stream, sorry */
dld_perror(error_string);
}
/* Debugging: define these if they are available */
static int
__objc_dynamic_undefined_symbol_count(void)
{
return dld_undefined_sym_count;
}
static char**
__objc_dynamic_list_undefined_symbols(void)
{
return dld_list_undefined_sym();
}
/* current dld version does not support an equivalent of dladdr() */
static char *
__objc_dynamic_get_symbol_path(dl_handle_t handle, dl_symbol_t symbol)
{
return NULL;
}
#endif /* __dld_load_h_INCLUDE */
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