glib/gmodule/gmodule-dl.c
Tim Janik d568a76ae4 do not return NULL symbols.
Wed Mar  1 05:34:47 2000  Tim Janik  <timj@gtk.org>

        * gmodule-beos.c (_g_module_symbol): do not return NULL symbols.

        * gmodule-os2.c: removed NetBSD specific defines.
        (_g_module_self): set an error message for unsupported behaviour.

        * gmodule-beos.c: many coding style fixups.
        (_g_module_open):
        (_g_module_self):
        (_g_module_close):
        (_g_module_symbol): bunch of memory leaks plugged.

        * gmodule-dl.c: make sure the error message returned from dlerror()
        is always != NULL, by using a wrapper function fetch_dlerror(). based
        on a patch to fix _g_module_symbol() for NetBSD from Scott Presnell
        <srp@zgi.com>.

        * gmodule-dld.c: minor indentation.

        * gmodule-win32.c: minor cleanups.

        * merges from glib-1-2.
2000-03-01 04:57:07 +00:00

155 lines
3.9 KiB
C

/* 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 Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the GLib Team and others 1997-1999. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
/*
* MT safe
*/
#include <dlfcn.h>
/* Perl includes <nlist.h> and <link.h> instead of <dlfcn.h> on some systmes? */
/* dlerror() is not implemented on all systems
*/
#ifndef G_MODULE_HAVE_DLERROR
# ifdef __NetBSD__
# define dlerror() g_strerror (errno)
# else /* !__NetBSD__ */
/* could we rely on errno's state here? */
# define dlerror() "unknown dl-error"
# endif /* !__NetBSD__ */
#endif /* G_MODULE_HAVE_DLERROR */
/* some flags are missing on some systems, so we provide
* harmless defaults.
* The Perl sources say, RTLD_LAZY needs to be defined as (1),
* at least for Solaris 1.
*
* Mandatory:
* RTLD_LAZY - resolve undefined symbols as code from the dynamic library
* is executed.
* RTLD_NOW - resolve all undefined symbols before dlopen returns, and fail
* if this cannot be done.
* Optionally:
* RTLD_GLOBAL - the external symbols defined in the library will be made
* available to subsequently loaded libraries.
*/
#ifndef RTLD_GLOBAL
#define RTLD_GLOBAL 0
#endif /* RTLD_GLOBAL */
#ifndef RTLD_LAZY
#define RTLD_LAZY 1
#endif /* RTLD_LAZY */
#ifndef RTLD_NOW
#define RTLD_NOW 0
#endif /* RTLD_NOW */
/* --- functions --- */
static gchar*
fetch_dlerror (void)
{
gchar *msg = dlerror ();
/* make sure we always return an error message != NULL */
return msg ? msg : "unknown dl-error";
}
static gpointer
_g_module_open (const gchar *file_name,
gboolean bind_lazy)
{
gpointer handle;
handle = dlopen (file_name, RTLD_GLOBAL | (bind_lazy ? RTLD_LAZY : RTLD_NOW));
if (!handle)
g_module_set_error (fetch_dlerror ());
return handle;
}
static gpointer
_g_module_self (void)
{
gpointer handle;
/* to query symbols from the program itself, special link options
* are required on some systems.
*/
handle = dlopen (NULL, RTLD_GLOBAL | RTLD_LAZY);
if (!handle)
g_module_set_error (fetch_dlerror ());
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 ());
}
}
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 ());
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, ".so", NULL);
} else if (strncmp (module_name, "lib", 3) == 0)
return g_strdup (module_name);
else
return g_strconcat ("lib", module_name, ".so", NULL);
}