1998-09-21 Ben Elliston <bje@cygnus.com>

        * New directory.  Moved files from ../gcc/objc.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@22514 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 834 insertions, 0 deletions

diff --git a/libobjc/init.c b/libobjc/init.c
new file mode 100644
index 00000000000..f1fea812318
--- /dev/null
+++ b/libobjc/init.c
@@ -0,0 +1,834 @@
+/* GNU Objective C Runtime initialization 
+   Copyright (C) 1993, 1995, 1996, 1997 Free Software Foundation, Inc.
+   Contributed by Kresten Krab Thorup
+   +load support contributed by Ovidiu Predescu <ovidiu@net-community.com>
+
+This file is part of GNU CC.
+
+GNU CC 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.
+
+GNU CC 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
+GNU CC; see the file COPYING.  If not, write to the Free Software
+Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* As a special exception, if you link this library with files compiled with
+   GCC to produce an executable, this does not cause the resulting executable
+   to be covered by the GNU General Public License. This exception does not
+   however invalidate any other reasons why the executable file might be
+   covered by the GNU General Public License.  */
+
+#include "runtime.h"
+
+/* The version number of this runtime.  This must match the number 
+   defined in gcc (objc-act.c) */
+#define OBJC_VERSION 8
+#define PROTOCOL_VERSION 2
+
+/* This list contains all modules currently loaded into the runtime */
+static struct objc_list* __objc_module_list = 0; 	/* !T:MUTEX */
+
+/* This list contains all proto_list's not yet assigned class links */
+static struct objc_list* unclaimed_proto_list = 0; 	/* !T:MUTEX */
+
+/* List of unresolved static instances.  */
+static struct objc_list *uninitialized_statics = 0; 	/* !T:MUTEX */
+
+/* Global runtime "write" mutex. */
+objc_mutex_t __objc_runtime_mutex = 0;
+
+/* Number of threads that are alive. */
+int __objc_runtime_threads_alive = 1;			/* !T:MUTEX */
+
+/* Check compiler vs runtime version */
+static void init_check_module_version (Module_t);
+
+/* Assign isa links to protos */
+static void __objc_init_protocols (struct objc_protocol_list* protos);
+
+/* Add protocol to class */
+static void __objc_class_add_protocols (Class, struct objc_protocol_list*);
+
+/* This is a hook which is called by __objc_exec_class every time a class
+   or a category is loaded into the runtime.  This may e.g. help a
+   dynamic loader determine the classes that have been loaded when
+   an object file is dynamically linked in */
+void (*_objc_load_callback)(Class class, Category* category); /* !T:SAFE */
+
+/* Is all categories/classes resolved? */
+BOOL __objc_dangling_categories = NO;           /* !T:UNUSED */
+
+extern SEL
+__sel_register_typed_name (const char *name, const char *types, 
+			   struct objc_selector *orig, BOOL is_const);
+
+/* Sends +load to all classes and categories in certain situations. */
+static void objc_send_load (void);
+
+/* Inserts all the classes defined in module in a tree of classes that
+   resembles the class hierarchy. This tree is traversed in preorder and the
+   classes in its nodes receive the +load message if these methods were not
+   executed before. The algorithm ensures that when the +load method of a class
+   is executed all the superclasses have been already received the +load
+   message. */
+static void __objc_create_classes_tree (Module_t module);
+
+static void __objc_call_callback (Module_t module);
+
+/* A special version that works only before the classes are completely
+   installed in the runtime. */
+static BOOL class_is_subclass_of_class (Class class, Class superclass);
+
+typedef struct objc_class_tree {
+  Class class;
+  struct objc_list *subclasses; /* `head' is pointer to an objc_class_tree */
+} objc_class_tree;
+
+/* This is a linked list of objc_class_tree trees. The head of these trees
+   are root classes (their super class is Nil). These different trees
+   represent different class hierarchies. */
+static struct objc_list *__objc_class_tree_list = NULL;
+
+/* Keeps the +load methods who have been already executed. This hash should
+   not be destroyed during the execution of the program. */
+static cache_ptr __objc_load_methods = NULL;
+
+/* Creates a tree of classes whose topmost class is directly inherited from
+   `upper' and the bottom class in this tree is `bottom_class'. The classes
+   in this tree are super classes of `bottom_class'. `subclasses' member
+   of each tree node point to the next subclass tree node. */
+static objc_class_tree *
+create_tree_of_subclasses_inherited_from (Class bottom_class, Class upper)
+{
+  Class superclass = bottom_class->super_class ?
+			objc_lookup_class ((char*)bottom_class->super_class)
+		      : Nil;
+					
+  objc_class_tree *tree, *prev;
+
+  DEBUG_PRINTF ("create_tree_of_subclasses_inherited_from:");
+  DEBUG_PRINTF ("bottom_class = %s, upper = %s\n",
+		(bottom_class ? bottom_class->name : NULL),
+		(upper ? upper->name : NULL));
+
+  tree = prev = objc_calloc (1, sizeof (objc_class_tree));
+  prev->class = bottom_class;
+
+  while (superclass != upper)
+    {
+      tree = objc_calloc (1, sizeof (objc_class_tree));
+      tree->class = superclass;
+      tree->subclasses = list_cons (prev, tree->subclasses);
+      superclass = (superclass->super_class ?
+			objc_lookup_class ((char*)superclass->super_class)
+		      : Nil);
+      prev = tree;
+    }
+
+  return tree;
+}
+
+/* Insert the `class' into the proper place in the `tree' class hierarchy. This
+   function returns a new tree if the class has been successfully inserted into
+   the tree or NULL if the class is not part of the classes hierarchy described
+   by `tree'. This function is private to objc_tree_insert_class(), you should
+   not call it directly. */
+static objc_class_tree *
+__objc_tree_insert_class (objc_class_tree *tree, Class class)
+{
+  DEBUG_PRINTF ("__objc_tree_insert_class: tree = %x, class = %s\n",
+		tree, class->name);
+
+  if (tree == NULL)
+    return create_tree_of_subclasses_inherited_from (class, NULL);
+  else if (class == tree->class)
+    {
+      /* `class' has been already inserted */
+      DEBUG_PRINTF ("1. class %s was previously inserted\n", class->name);
+      return tree;
+    }
+  else if ((class->super_class ?
+		    objc_lookup_class ((char*)class->super_class)
+		  : Nil)
+	    == tree->class)
+    {
+      /* If class is a direct subclass of tree->class then add class to the
+	 list of subclasses. First check to see if it wasn't already
+	 inserted. */
+      struct objc_list *list = tree->subclasses;
+      objc_class_tree *node;
+
+      while (list)
+	{
+	  /* Class has been already inserted; do nothing just return
+	     the tree. */
+	  if (((objc_class_tree*)list->head)->class == class)
+	    {
+	      DEBUG_PRINTF ("2. class %s was previously inserted\n",
+			    class->name);
+	      return tree;
+	    }
+	  list = list->tail;
+	}
+
+      /* Create a new node class and insert it into the list of subclasses */
+      node = objc_calloc (1, sizeof (objc_class_tree));
+      node->class = class;
+      tree->subclasses = list_cons (node, tree->subclasses);
+      DEBUG_PRINTF ("3. class %s inserted\n", class->name);
+      return tree;
+    }
+  else
+    {
+      /* The class is not a direct subclass of tree->class. Search for class's
+         superclasses in the list of subclasses. */
+      struct objc_list *subclasses = tree->subclasses;
+
+      /* Precondition: the class must be a subclass of tree->class; otherwise
+         return NULL to indicate our caller that it must take the next tree. */
+      if (!class_is_subclass_of_class (class, tree->class))
+	return NULL;
+
+      for (; subclasses != NULL; subclasses = subclasses->tail)
+	{
+	  Class aClass = ((objc_class_tree*)(subclasses->head))->class;
+
+	  if (class_is_subclass_of_class (class, aClass))
+	    {
+	      /* If we found one of class's superclasses we insert the class
+	         into its subtree and return the original tree since nothing
+		 has been changed. */
+	      subclasses->head
+		  = __objc_tree_insert_class (subclasses->head, class);
+ 	      DEBUG_PRINTF ("4. class %s inserted\n", class->name);
+	      return tree;
+	    }
+	}
+
+      /* We haven't found a subclass of `class' in the `subclasses' list.
+         Create a new tree of classes whose topmost class is a direct subclass
+	 of tree->class. */
+      {
+	objc_class_tree *new_tree
+	    = create_tree_of_subclasses_inherited_from (class, tree->class);
+	tree->subclasses = list_cons (new_tree, tree->subclasses);
+ 	DEBUG_PRINTF ("5. class %s inserted\n", class->name);
+	return tree;
+      }
+    }
+}
+
+/* This function inserts `class' in the right tree hierarchy classes. */
+static void
+objc_tree_insert_class (Class class)
+{
+  struct objc_list *list_node;
+  objc_class_tree *tree;
+
+  list_node = __objc_class_tree_list;
+  while (list_node)
+    {
+      tree = __objc_tree_insert_class (list_node->head, class);
+      if (tree)
+	{
+	  list_node->head = tree;
+	  break;
+	}
+      else
+	list_node = list_node->tail;
+    }
+
+  /* If the list was finished but the class hasn't been inserted, insert it
+     here. */
+  if (!list_node)
+    {
+      __objc_class_tree_list = list_cons (NULL, __objc_class_tree_list);
+      __objc_class_tree_list->head = __objc_tree_insert_class (NULL, class);
+    }
+}
+
+/* Traverse tree in preorder. Used to send +load. */
+static void
+objc_preorder_traverse (objc_class_tree *tree,
+			int level,
+			void (*function)(objc_class_tree*, int))
+{
+  struct objc_list *node;
+
+  (*function) (tree, level);
+  for (node = tree->subclasses; node; node = node->tail)
+    objc_preorder_traverse (node->head, level + 1, function);
+}
+
+/* Traverse tree in postorder. Used to destroy a tree. */
+static void
+objc_postorder_traverse (objc_class_tree *tree,
+			int level,
+			void (*function)(objc_class_tree*, int))
+{
+  struct objc_list *node;
+
+  for (node = tree->subclasses; node; node = node->tail)
+    objc_postorder_traverse (node->head, level + 1, function);
+  (*function) (tree, level);
+}
+
+/* Used to print a tree class hierarchy. */
+#ifdef DEBUG
+static void
+__objc_tree_print (objc_class_tree *tree, int level)
+{
+  int i;
+
+  for (i = 0; i < level; i++)
+    printf ("  ");
+  printf ("%s\n", tree->class->name);
+}
+#endif
+
+/* Walks on a linked list of methods in the reverse order and executes all
+   the methods corresponding to `op' selector. Walking in the reverse order
+   assures the +load of class is executed first and then +load of categories
+   because of the way in which categories are added to the class methods. */
+static void
+__objc_send_message_in_list (MethodList_t method_list, Class class, SEL op)
+{
+  int i;
+
+  if (!method_list)
+    return;
+
+  /* First execute the `op' message in the following method lists */
+  __objc_send_message_in_list (method_list->method_next, class, op);
+
+  /* Search the method list. */
+  for (i = 0; i < method_list->method_count; i++)
+    {
+      Method_t mth = &method_list->method_list[i];
+
+      if (mth->method_name && sel_eq (mth->method_name, op)
+	  && !hash_is_key_in_hash (__objc_load_methods, mth->method_name))
+	{
+	  /* The method was found and wasn't previously executed. */
+	  (*mth->method_imp) ((id)class, mth->method_name);
+
+	  /* Add this method into the +load hash table */
+	  hash_add (&__objc_load_methods, mth->method_imp, mth->method_imp);
+
+	  DEBUG_PRINTF ("sending +load in class: %s\n", class->name);
+
+	  break;
+	}
+    }
+}
+
+static void
+__objc_send_load (objc_class_tree *tree, int level)
+{
+  static SEL load_sel = 0;
+  Class class = tree->class;
+  MethodList_t method_list = class->class_pointer->methods;
+
+  if (!load_sel)
+    load_sel = sel_register_name ("load");
+
+  __objc_send_message_in_list (method_list, class, load_sel);
+}
+
+static void
+__objc_destroy_class_tree_node (objc_class_tree *tree, int level)
+{
+  objc_free (tree);
+}
+
+/* This is used to check if the relationship between two classes before the
+   runtime completely installs the classes. */
+static BOOL
+class_is_subclass_of_class (Class class, Class superclass)
+{
+  for (; class != Nil;)
+    {
+      if (class == superclass)
+	return YES;
+      class = (class->super_class ?
+		  objc_lookup_class ((char*)class->super_class)
+		: Nil);
+    }
+
+  return NO;
+}
+
+/* This list contains all the classes in the runtime system for whom their
+   superclasses are not yet know to the runtime. */
+static struct objc_list* unresolved_classes = 0;
+
+/* Static function used to reference the Object and NXConstantString classes.
+ */
+static void
+__objc_force_linking (void)
+{
+  extern void __objc_linking (void);
+  __objc_linking ();
+
+  /* Call the function to avoid compiler warning */
+  __objc_force_linking ();
+}
+
+/* Run through the statics list, removing modules as soon as all its statics
+   have been initialized.  */
+static void
+objc_init_statics (void)
+{
+  struct objc_list **cell = &uninitialized_statics;
+  struct objc_static_instances **statics_in_module;
+
+  objc_mutex_lock(__objc_runtime_mutex);
+
+  while (*cell)
+    {
+      int module_initialized = 1;
+
+      for (statics_in_module = (*cell)->head;
+	   *statics_in_module; statics_in_module++)
+	{
+	  struct objc_static_instances *statics = *statics_in_module;
+	  Class class = objc_lookup_class (statics->class_name);
+
+	  if (!class)
+	    module_initialized = 0;
+	  /* Actually, the static's class_pointer will be NULL when we
+             haven't been here before.  However, the comparison is to be
+             reminded of taking into account class posing and to think about
+             possible semantics...  */
+	  else if (class != statics->instances[0]->class_pointer)
+	    {
+	      id *inst;
+
+	      for (inst = &statics->instances[0]; *inst; inst++)
+		{
+		  (*inst)->class_pointer = class;
+
+		  /* ??? Make sure the object will not be freed.  With
+                     refcounting, invoke `-retain'.  Without refcounting, do
+                     nothing and hope that `-free' will never be invoked.  */
+
+		  /* ??? Send the object an `-initStatic' or something to
+                     that effect now or later on?  What are the semantics of
+                     statically allocated instances, besides the trivial
+                     NXConstantString, anyway?  */
+		}
+	    }
+	}
+      if (module_initialized)
+	{
+	  /* Remove this module from the uninitialized list.  */
+	  struct objc_list *this = *cell;
+	  *cell = this->tail;
+	  objc_free(this);
+	}
+      else
+	cell = &(*cell)->tail;
+    }
+
+  objc_mutex_unlock(__objc_runtime_mutex);
+} /* objc_init_statics */
+
+/* This function is called by constructor functions generated for each
+   module compiled.  (_GLOBAL_$I$...) The purpose of this function is to
+   gather the module pointers so that they may be processed by the
+   initialization routines as soon as possible */
+
+void
+__objc_exec_class (Module_t module)
+{
+  /* Have we processed any constructors previously?  This flag is used to
+     indicate that some global data structures need to be built.  */
+  static BOOL previous_constructors = 0;
+
+  static struct objc_list* unclaimed_categories = 0;
+
+  /* The symbol table (defined in objc-api.h) generated by gcc */
+  Symtab_t symtab = module->symtab;
+
+  /* The statics in this module */
+  struct objc_static_instances **statics
+    = symtab->defs[symtab->cls_def_cnt + symtab->cat_def_cnt];
+
+  /* Entry used to traverse hash lists */
+  struct objc_list** cell;
+
+  /* The table of selector references for this module */
+  SEL selectors = symtab->refs; 
+
+  /* dummy counter */
+  int i;
+
+  DEBUG_PRINTF ("received module: %s\n", module->name);
+
+  /* check gcc version */
+  init_check_module_version(module);
+
+  /* On the first call of this routine, initialize some data structures.  */
+  if (!previous_constructors)
+    {
+	/* Initialize thread-safe system */
+      __objc_init_thread_system();
+      __objc_runtime_threads_alive = 1;
+      __objc_runtime_mutex = objc_mutex_allocate();
+
+      __objc_init_selector_tables();
+      __objc_init_class_tables();
+      __objc_init_dispatch_tables();
+      __objc_class_tree_list = list_cons (NULL, __objc_class_tree_list);
+      __objc_load_methods
+	  = hash_new (128, (hash_func_type)hash_ptr, compare_ptrs);
+      previous_constructors = 1;
+    }
+
+  /* Save the module pointer for later processing. (not currently used) */
+  objc_mutex_lock(__objc_runtime_mutex);
+  __objc_module_list = list_cons(module, __objc_module_list);
+
+  /* Replace referenced selectors from names to SEL's.  */
+  if (selectors)
+    {
+      for (i = 0; selectors[i].sel_id; ++i)
+	{
+	  const char *name, *type;
+	  name = (char*)selectors[i].sel_id;
+	  type = (char*)selectors[i].sel_types;
+	  /* Constructors are constant static data so we can safely store
+	     pointers to them in the runtime structures. is_const == YES */
+	  __sel_register_typed_name (name, type, 
+				     (struct objc_selector*)&(selectors[i]),
+				     YES);
+	}
+    }
+
+  /* Parse the classes in the load module and gather selector information.  */
+  DEBUG_PRINTF ("gathering selectors from module: %s\n", module->name);
+  for (i = 0; i < symtab->cls_def_cnt; ++i)
+    {
+      Class class = (Class) symtab->defs[i];
+      const char* superclass = (char*)class->super_class;
+
+      /* Make sure we have what we think.  */
+      assert (CLS_ISCLASS(class));
+      assert (CLS_ISMETA(class->class_pointer));
+      DEBUG_PRINTF ("phase 1, processing class: %s\n", class->name);
+
+      /* Initialize the subclass list to be NULL.
+	 In some cases it isn't and this crashes the program. */
+      class->subclass_list = NULL;
+
+      /* Store the class in the class table and assign class numbers.  */
+      __objc_add_class_to_hash (class);
+
+      /* Register all of the selectors in the class and meta class.  */
+      __objc_register_selectors_from_class (class);
+      __objc_register_selectors_from_class ((Class) class->class_pointer);
+
+      /* Install the fake dispatch tables */
+      __objc_install_premature_dtable(class);
+      __objc_install_premature_dtable(class->class_pointer);
+
+      /* Register the instance methods as class methods, this is
+	 only done for root classes. */
+      __objc_register_instance_methods_to_class(class);
+
+      if (class->protocols)
+	__objc_init_protocols (class->protocols);
+
+      /* Check to see if the superclass is known in this point. If it's not
+	 add the class to the unresolved_classes list. */
+      if (superclass && !objc_lookup_class (superclass))
+	unresolved_classes = list_cons (class, unresolved_classes);
+   }
+
+  /* Process category information from the module.  */
+  for (i = 0; i < symtab->cat_def_cnt; ++i)
+    {
+      Category_t category = symtab->defs[i + symtab->cls_def_cnt];
+      Class class = objc_lookup_class (category->class_name);
+      
+      /* If the class for the category exists then append its methods.  */
+      if (class)
+	{
+
+	  DEBUG_PRINTF ("processing categories from (module,object): %s, %s\n",
+			module->name,
+			class->name);
+
+	  /* Do instance methods.  */
+	  if (category->instance_methods)
+	    class_add_method_list (class, category->instance_methods);
+
+	  /* Do class methods.  */
+	  if (category->class_methods)
+	    class_add_method_list ((Class) class->class_pointer, 
+				   category->class_methods);
+
+	  if (category->protocols)
+	    {
+	      __objc_init_protocols (category->protocols);
+	      __objc_class_add_protocols (class, category->protocols);
+	    }
+
+          /* Register the instance methods as class methods, this is
+             only done for root classes. */
+          __objc_register_instance_methods_to_class(class);
+	}
+      else
+	{
+	  /* The object to which the category methods belong can't be found.
+	     Save the information.  */
+	  unclaimed_categories = list_cons(category, unclaimed_categories);
+	}
+    }
+
+  if (statics)
+    uninitialized_statics = list_cons (statics, uninitialized_statics);
+  if (uninitialized_statics)
+    objc_init_statics ();
+
+  /* Scan the unclaimed category hash.  Attempt to attach any unclaimed
+     categories to objects.  */
+  for (cell = &unclaimed_categories;
+       *cell;
+       ({ if (*cell) cell = &(*cell)->tail; }))
+    {
+      Category_t category = (*cell)->head;
+      Class class = objc_lookup_class (category->class_name);
+      
+      if (class)
+	{
+	  DEBUG_PRINTF ("attaching stored categories to object: %s\n",
+			class->name);
+	  
+	  list_remove_head (cell);
+	  
+	  if (category->instance_methods)
+	    class_add_method_list (class, category->instance_methods);
+	  
+	  if (category->class_methods)
+	    class_add_method_list ((Class) class->class_pointer,
+				   category->class_methods);
+
+	  if (category->protocols)
+	    {
+	      __objc_init_protocols (category->protocols);
+	      __objc_class_add_protocols (class, category->protocols);
+	    }
+
+          /* Register the instance methods as class methods, this is
+             only done for root classes. */
+          __objc_register_instance_methods_to_class(class);
+	}
+    }
+  
+  if (unclaimed_proto_list && objc_lookup_class ("Protocol"))
+    {
+      list_mapcar (unclaimed_proto_list,(void(*)(void*))__objc_init_protocols);
+      list_free (unclaimed_proto_list);
+      unclaimed_proto_list = 0;
+    }
+
+  objc_send_load ();
+
+  objc_mutex_unlock(__objc_runtime_mutex);
+}
+
+static void objc_send_load (void)
+{
+  if (!__objc_module_list)
+    return;
+ 
+  /* Try to find out if all the classes loaded so far also have their
+     superclasses known to the runtime. We suppose that the objects that are
+     allocated in the +load method are in general of a class declared in the
+     same module. */
+  if (unresolved_classes)
+    {
+      Class class = unresolved_classes->head;
+
+      while (objc_lookup_class ((char*)class->super_class))
+	{
+	  list_remove_head (&unresolved_classes);
+	  if (unresolved_classes)
+	    class = unresolved_classes->head;
+	  else
+	    break;
+	}
+
+      /*
+       * If we still have classes for whom we don't have yet their super
+       * classes known to the runtime we don't send the +load messages.
+       */
+      if (unresolved_classes)
+	return;
+    }
+
+  /* Special check to allow creating and sending messages to constant strings
+     in +load methods. If these classes are not yet known, even if all the
+     other classes are known, delay sending of +load. */
+  if (!objc_lookup_class ("NXConstantString") ||
+      !objc_lookup_class ("Object"))
+    return;
+
+  /* Iterate over all modules in the __objc_module_list and call on them the
+     __objc_create_classes_tree function. This function creates a tree of
+     classes that resembles the class hierarchy. */
+  list_mapcar (__objc_module_list, (void(*)(void*))__objc_create_classes_tree);
+
+  while (__objc_class_tree_list)
+    {
+#ifdef DEBUG
+      objc_preorder_traverse (__objc_class_tree_list->head,
+			      0, __objc_tree_print);
+#endif
+      objc_preorder_traverse (__objc_class_tree_list->head,
+			      0, __objc_send_load);
+      objc_postorder_traverse (__objc_class_tree_list->head,
+			      0, __objc_destroy_class_tree_node);
+      list_remove_head (&__objc_class_tree_list);
+    }
+
+  list_mapcar (__objc_module_list, (void(*)(void*))__objc_call_callback);
+  list_free (__objc_module_list);
+  __objc_module_list = NULL;
+}
+
+static void
+__objc_create_classes_tree (Module_t module)
+{
+  /* The runtime mutex is locked in this point */
+
+  Symtab_t symtab = module->symtab;
+  int i;
+
+  /* Iterate thru classes defined in this module and insert them in the classes
+     tree hierarchy. */
+  for (i = 0; i < symtab->cls_def_cnt; i++)
+    {
+      Class class = (Class) symtab->defs[i];
+
+      objc_tree_insert_class (class);
+    }
+}
+
+static void
+__objc_call_callback (Module_t module)
+{
+  /* The runtime mutex is locked in this point */
+
+  Symtab_t symtab = module->symtab;
+  int i;
+
+  /* Iterate thru classes defined in this module and call the callback for
+     each one. */
+  for (i = 0; i < symtab->cls_def_cnt; i++)
+    {
+      Class class = (Class) symtab->defs[i];
+
+      /* Call the _objc_load_callback for this class. */
+      if (_objc_load_callback)
+	_objc_load_callback(class, 0);
+    }
+
+  /* Call the _objc_load_callback for categories. Don't register the instance
+     methods as class methods for categories to root classes since they were
+     already added in the class. */
+  for (i = 0; i < symtab->cat_def_cnt; i++)
+    {
+      Category_t category = symtab->defs[i + symtab->cls_def_cnt];
+      Class class = objc_lookup_class (category->class_name);
+      
+      if (_objc_load_callback)
+	_objc_load_callback(class, category);
+    }
+}
+
+/* Sanity check the version of gcc used to compile `module'*/
+static void init_check_module_version(Module_t module)
+{
+  if ((module->version != OBJC_VERSION) || (module->size != sizeof (Module)))
+    {
+      int code;
+
+      if(module->version > OBJC_VERSION)
+	code = OBJC_ERR_OBJC_VERSION;
+      else if (module->version < OBJC_VERSION)
+	code = OBJC_ERR_GCC_VERSION;
+      else
+	code = OBJC_ERR_MODULE_SIZE;
+
+      objc_error(nil, code, "Module %s version %d doesn't match runtime %d\n",
+	       module->name, (int)module->version, OBJC_VERSION);
+    }
+}
+
+static void
+__objc_init_protocols (struct objc_protocol_list* protos)
+{
+  int i;
+  static Class proto_class = 0;
+
+  if (! protos)
+    return;
+
+  objc_mutex_lock(__objc_runtime_mutex);
+
+  if (!proto_class)
+    proto_class = objc_lookup_class("Protocol");
+
+  if (!proto_class)
+    {
+      unclaimed_proto_list = list_cons (protos, unclaimed_proto_list);
+      objc_mutex_unlock(__objc_runtime_mutex);
+      return;
+    }
+
+#if 0
+  assert (protos->next == 0);	/* only single ones allowed */
+#endif
+
+  for(i = 0; i < protos->count; i++)
+    {
+      struct objc_protocol* aProto = protos->list[i];
+      if (((size_t)aProto->class_pointer) == PROTOCOL_VERSION)
+	{
+	  /* assign class pointer */
+	  aProto->class_pointer = proto_class;
+
+	  /* init super protocols */
+	  __objc_init_protocols (aProto->protocol_list);
+	}
+      else if (protos->list[i]->class_pointer != proto_class)
+	{
+	  objc_error(nil, OBJC_ERR_PROTOCOL_VERSION,
+		     "Version %d doesn't match runtime protocol version %d\n",
+		     (int)((char*)protos->list[i]->class_pointer-(char*)0),
+		     PROTOCOL_VERSION);
+	}
+    }
+
+  objc_mutex_unlock(__objc_runtime_mutex);
+}
+
+static void __objc_class_add_protocols (Class class,
+					struct objc_protocol_list* protos)
+{
+  /* Well... */
+  if (! protos)
+    return;
+
+  /* Add it... */
+  protos->next = class->protocols;
+  class->protocols = protos;
+}