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authorMarius Vollmer <mvo@zagadka.de>2001-05-20 19:26:23 +0000
committerMarius Vollmer <mvo@zagadka.de>2001-05-20 19:26:23 +0000
commite2ab7927bfab05cb08b611ec8827258a395b72ae (patch)
tree9dae7d2406bdef8e6c7468257c350c21e4fd0ab0 /libguile/extensions.c
parent2fc933fe89cc3934ea35e4f02e62d9b006ddad7f (diff)
downloadguile-e2ab7927bfab05cb08b611ec8827258a395b72ae.tar.gz
New files.
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+/* extensions.c - registering and loading extensions.
+ *
+ * Copyright (C) 2001 Free Software Foundation, Inc.
+ *
+ * This program 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.
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA
+ *
+ * As a special exception, the Free Software Foundation gives permission
+ * for additional uses of the text contained in its release of GUILE.
+ *
+ * The exception is that, if you link the GUILE library with other files
+ * to produce an executable, this does not by itself cause the
+ * resulting executable to be covered by the GNU General Public License.
+ * Your use of that executable is in no way restricted on account of
+ * linking the GUILE library code into it.
+ *
+ * This exception does not however invalidate any other reasons why
+ * the executable file might be covered by the GNU General Public License.
+ *
+ * This exception applies only to the code released by the
+ * Free Software Foundation under the name GUILE. If you copy
+ * code from other Free Software Foundation releases into a copy of
+ * GUILE, as the General Public License permits, the exception does
+ * not apply to the code that you add in this way. To avoid misleading
+ * anyone as to the status of such modified files, you must delete
+ * this exception notice from them.
+ *
+ * If you write modifications of your own for GUILE, it is your choice
+ * whether to permit this exception to apply to your modifications.
+ * If you do not wish that, delete this exception notice. */
+
+#include "libguile/_scm.h"
+#include "libguile/strings.h"
+#include "libguile/gc.h"
+#include "libguile/dynl.h"
+
+#include "libguile/extensions.h"
+
+struct extension {
+ struct extension *next;
+ const char *lib;
+ const char *init;
+ void (*func)(void *);
+ void *data;
+};
+
+static struct extension *registered_extensions;
+
+void
+scm_c_register_extension (const char *lib, const char *init,
+ void (*func) (void *), void *data)
+{
+ struct extension *ext = scm_must_malloc (sizeof(struct extension),
+ "scm_register_extension");
+ ext->lib = scm_must_strdup (lib);
+ ext->init = scm_must_strdup (init);
+ ext->func = func;
+ ext->data = data;
+
+ ext->next = registered_extensions;
+ registered_extensions = ext;
+}
+
+static void
+load_extension (SCM lib, SCM init)
+{
+ /* Search the registry. */
+ {
+ struct extension *ext;
+
+ for (ext = registered_extensions; ext; ext = ext->next)
+ if (!strcmp (ext->lib, SCM_STRING_CHARS (lib))
+ && !strcmp (ext->init, SCM_STRING_CHARS (init)))
+ {
+ ext->func (ext->data);
+ return;
+ }
+ }
+
+ /* Dynamically link the library. */
+
+ scm_dynamic_call (init, scm_dynamic_link (lib));
+}
+
+void
+scm_c_load_extension (const char *lib, const char *init)
+{
+ load_extension (scm_makfrom0str (lib), scm_makfrom0str (init));
+}
+
+SCM_DEFINE (scm_load_extension, "load-extension", 2, 0, 0,
+ (SCM lib, SCM init),
+ "Load and initilize the extension designated by LIB and INIT."
+"When there is no pre-registered function for LIB/INIT, this is "
+"equivalent to "
+" "
+" (dynamic-call INIT (dynamic-link LIB)) "
+" "
+"When there is a pre-registered function, that function is called "
+"instead. "
+" "
+"Normally, there is no pre-registered function. This option exists "
+"only for situations where dynamic linking is unavailable or unwanted. "
+"In that case, you would statically link your program with the desired "
+"library, and register its init function right after Guile has been "
+"initialized. "
+" "
+"LIB should be a string denoting a shared library without any file type "
+"suffix such as \".so\". The suffix is provided automatically. It "
+"should also not contain any directory components. Libraries that "
+"implement Guile Extensions should be put into the normal locations for "
+"shared libraries. We recommend to use the naming convention "
+"libguile-bla-blum for a extension related to a module `(bla blum)'. "
+" "
+"The normal way for a extension to be used is to write a small Scheme "
+"file that defines a module, and to load the extension into this "
+"module. When the module is auto-loaded, the extension is loaded as "
+"well. For example, "
+" "
+" (define-module (bla blum)) "
+" "
+" (load-extension \"libguile-bla-blum\" \"bla_init_blum\")")
+#define FUNC_NAME s_scm_load_extension
+{
+ SCM_VALIDATE_STRING (1, lib);
+ SCM_VALIDATE_STRING (2, init);
+ load_extension (lib, init);
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+void
+scm_init_extensions ()
+{
+ registered_extensions = NULL;
+#ifndef SCM_MAGIC_SNARFER
+#include "libguile/extensions.x"
+#endif
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/