glib/gmodule/gmodule-ar.c

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/* GMODULE - GLIB wrapper code for dynamic module loading
* Copyright (C) 1998, 2000 Tim Janik
*
* This library 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 library 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
2014-01-23 12:58:29 +01:00
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* MT safe
*/
/* because we are compatible with archive format only since AIX 4.3 */
#define __AR_BIG__
#include "config.h"
#include <ar.h>
#include <stdlib.h>
#include <dlfcn.h>
/* --- functions --- */
static gchar*
fetch_dlerror (gboolean replace_null)
{
gchar *msg = dlerror ();
/* make sure we always return an error message != NULL, if
* expected to do so. */
if (!msg && replace_null)
return "unknown dl-error";
return msg;
}
static gchar* _g_module_get_member(const gchar* file_name)
{
gchar* member = NULL;
struct fl_hdr file_header;
struct ar_hdr ar_header;
long first_member;
long name_len;
int fd;
fd = open(file_name, O_RDONLY);
if (fd == -1)
return NULL;
if (read(fd, (void*)&file_header, FL_HSZ) != FL_HSZ)
goto exit;
if (strncmp(file_header.fl_magic, AIAMAGBIG, SAIAMAG) != 0)
goto exit;
/* read first archive file member header */
first_member = atol(file_header.fl_fstmoff);
if (lseek(fd, first_member, SEEK_SET) != first_member)
goto exit;
if (read(fd, (void*)&ar_header, AR_HSZ - 2) != AR_HSZ - 2)
goto exit;
/* read member name */
name_len = atol(ar_header.ar_namlen);
member = g_malloc(name_len+1);
if (!member)
goto exit;
if (read(fd, (void*)member, name_len) != name_len)
{
g_free(member);
member = NULL;
goto exit;
}
member[name_len] = 0;
exit:
close(fd);
return member;
}
static gpointer
_g_module_open (const gchar *file_name,
gboolean bind_lazy,
gboolean bind_local)
{
gpointer handle;
gchar* member;
gchar* full_name;
/* extract name of first member of archive */
member = _g_module_get_member (file_name);
if (member != NULL)
{
full_name = g_strconcat (file_name, "(", member, ")", NULL);
g_free (member);
}
else
full_name = g_strdup (file_name);
handle = dlopen (full_name,
(bind_local ? RTLD_LOCAL : RTLD_GLOBAL) | RTLD_MEMBER | (bind_lazy ? RTLD_LAZY : RTLD_NOW));
g_free (full_name);
if (!handle)
g_module_set_error (fetch_dlerror (TRUE));
return handle;
}
static gpointer
_g_module_self (void)
{
gpointer handle;
handle = dlopen (NULL, RTLD_GLOBAL | RTLD_LAZY);
if (!handle)
g_module_set_error (fetch_dlerror (TRUE));
return handle;
}
static void
_g_module_close (gpointer handle,
gboolean is_unref)
{
/* are there any systems out there that have dlopen()/dlclose()
* without a reference count implementation?
*/
is_unref |= 1;
if (is_unref)
{
if (dlclose (handle) != 0)
g_module_set_error (fetch_dlerror (TRUE));
}
}
static gpointer
_g_module_symbol (gpointer handle,
const gchar *symbol_name)
{
gpointer p;
p = dlsym (handle, symbol_name);
if (!p)
g_module_set_error (fetch_dlerror (FALSE));
return p;
}
static gchar*
_g_module_build_path (const gchar *directory,
const gchar *module_name)
{
if (directory && *directory) {
if (strncmp (module_name, "lib", 3) == 0)
return g_strconcat (directory, "/", module_name, NULL);
else
return g_strconcat (directory, "/lib", module_name, "." G_MODULE_SUFFIX, NULL);
} else if (strncmp (module_name, "lib", 3) == 0)
return g_strdup (module_name);
else
return g_strconcat ("lib", module_name, "." G_MODULE_SUFFIX, NULL);
}