Initial revision

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@251 72102866-910b-0410-8b05-ffd578937521

Source/objc-load.c

@@ -0,0 +1,224 @@
+/*
+    objc-load - Dynamically load in Obj-C modules (Classes, Categories)
+
+    Written by Adam Fedor, Pedja Bogdanovich
+
+    $Id$
+
+    BUGS:
+	- unloading modules not implemented
+	- would like to raise exceptions without having to turn this into
+	  a .m file (right now NSBundle does this for us, ok?)
+    
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <objc/objc-api.h>
+#include <objc/list.h>
+#include <foundation/objc-load.h>
+
+/* include the interface to the dynamic linker */
+#include "dynamic-load.h"
+
+/* From the objc runtime -- needed when invalidating the dtable */
+extern void __objc_install_premature_dtable(Class);
+extern void sarray_free(struct sarray*);
+extern struct sarray *__objc_uninstalled_dtable;
+
+extern char *objc_find_executable(const char *name);
+
+/* This is the GNU name for the CTOR list */
+#define CTOR_LIST       "___CTOR_LIST__"
+
+/* External variables needed to find the path to the executable program.  */
+extern char     **NSArgv;
+
+/* dynamic_loaded is YES if the dynamic loader was sucessfully initialized. */
+static BOOL	dynamic_loaded;
+
+/* Our current callback function */
+void (*_objc_load_load_callback)(Class, Category*) = 0;
+
+/* List of modules we have loaded (by handle) */
+static struct objc_list *dynamic_handles = NULL;
+
+/* Check to see if there are any undefined symbols. Print them out.
+*/
+static int
+objc_check_undefineds(FILE *errorStream)
+{
+    int count = __objc_dynamic_undefined_symbol_count();
+
+    if (count != 0) {
+        int  i;
+        char **undefs;
+        undefs = __objc_dynamic_list_undefined_symbols();
+        if (errorStream)
+	    fprintf(errorStream, "Undefined symbols:\n");
+        for (i=0; i < count; i++)
+            if (errorStream)
+		fprintf(errorStream, "  %s\n", undefs[i]);
+	return 1;
+    }
+    return 0;
+}
+
+char *
+objc_executable_location()
+{
+    return objc_find_executable(NSArgv[0]);
+}
+
+/* Invalidate the dtable so it will be rebuild when a message is sent to
+   the object */
+static void
+objc_invalidate_dtable(Class class)
+{
+    Class s;
+
+    if (class->dtable == __objc_uninstalled_dtable) 
+	return;
+    sarray_free(class->dtable);
+    __objc_install_premature_dtable(class);
+    for (s=class->subclass_list; s; s=s->sibling_class) 
+	objc_invalidate_dtable(s);
+}
+
+/* Initialize for dynamic loading */
+static int 
+objc_initialize_loading(FILE *errorStream)
+{
+    char *path;
+
+    dynamic_loaded = NO;
+    path   = objc_executable_location();
+#ifdef DEBUG
+    printf("Debug (objc-load): initializing dynamic loader for %s\n", path);
+#endif
+    if (__objc_dynamic_init(path)) {
+	if (errorStream)
+	    __objc_dynamic_error(errorStream, "Error (objc-load): Cannot initialize dynamic linker");
+	return 1;
+    } else
+	dynamic_loaded = YES;
+    free(path);
+
+    return 0;
+}
+
+/* A callback received from the Object initializer (_objc_exec_class).
+   Do what we need to do and call our own callback.
+*/
+static void 
+objc_load_callback(Class class, Category* category)
+{
+    /* Invalidate the dtable, so it will be rebuilt correctly */
+    if (class != 0 && category != 0) {
+	objc_invalidate_dtable(class);
+	objc_invalidate_dtable(class->class_pointer);
+    }
+
+    if (_objc_load_load_callback)
+	_objc_load_load_callback(class, category);
+}
+
+long
+objc_load_module(
+	const char *filename,
+	FILE *errorStream,
+	void (*loadCallback)(Class, Category*),
+	void **header,
+	char *debugFilename)
+
+{
+    typedef void (*void_fn)();
+    void_fn *ctor_list;
+    dl_handle_t handle;
+    int i;
+
+    if (!dynamic_loaded)
+        if (objc_initialize_loading(errorStream))
+            return 1;
+
+    /* Link in the object file */
+#ifdef DEBUG
+    printf("Debug (objc-load): Linking file %s\n", filename);
+#endif
+    handle = __objc_dynamic_link(filename, 1, debugFilename);
+    if (handle == 0) {
+	if (errorStream)
+	    __objc_dynamic_error(errorStream, "Error (objc-load)");
+	return 1;
+    }
+    dynamic_handles = list_cons(handle, dynamic_handles);
+
+    /* If there are any undefined symbols, we can't load the bundle */
+    if (objc_check_undefineds(errorStream)) {
+	__objc_dynamic_unlink(handle);
+	return 1;
+    }
+
+    /* Get the constructor list and load in the objects */
+    ctor_list = (void_fn *)__objc_dynamic_find_symbol(handle, CTOR_LIST);
+    if (!ctor_list) {
+	if (errorStream)
+	    fprintf(errorStream, "Error (objc-load): Cannot load objects (no CTOR list)\n");
+	return 1;
+    }
+
+    _objc_load_load_callback = loadCallback;
+    _objc_load_callback = objc_load_callback;
+#ifdef DEBUG
+    printf("Debug (objc-load): %d modules\n", (int)ctor_list[0]);
+#endif
+    for (i=1; ctor_list[i]; i++) {
+#ifdef DEBUG
+	printf("Debug (objc-load): Invoking CTOR %p\n", ctor_list[i]);
+#endif
+	ctor_list[i]();
+    }
+    _objc_load_callback = 0;
+    _objc_load_load_callback = 0;
+    return 0;
+}
+
+long 
+objc_unload_module(
+	FILE *errorStream,
+	void (*unloadCallback)(Class, Category*))
+{
+    if (!dynamic_loaded)
+        return 1;
+
+    if (errorStream)
+        fprintf(errorStream, "Warning: unloading modules not implemented\n");
+    return 0;
+}
+
+long objc_loadModules(char *files[],FILE *errorStream,
+	void (*callback)(Class,Category*),
+	void **header,
+	char *debugFilename)
+{
+    while (*files) {
+	if (objc_load_module(*files, errorStream, callback, 
+		(void *)header, debugFilename)) 
+	    return 1;
+	files++;
+    }
+    return 0;
+}
+
+long 
+objc_unloadModules(
+	FILE *errorStream,
+	void (*unloadCallback)(Class, Category*))
+{
+    if (!dynamic_loaded)
+        return 1;
+
+    if (errorStream)
+        fprintf(errorStream, "Warning: unloading modules not implemented\n");
+    return 0;
+}