objc-actions.c

早期freebsd实现

	*q = 0;
      }

    /* Make the constructor name from the name we have found.  */
    buf = (char *) xmalloc (sizeof (CONSTRUCTOR_NAME_FORMAT)
			    + strlen (global_object_name));
    sprintf (buf, CONSTRUCTOR_NAME_FORMAT, global_object_name);

    /* Declare void __objc_execClass (void*); */

    void_list_node = build_tree_list (NULL_TREE, void_type_node);
    function_type
      = build_function_type (void_type_node,  
			     tree_cons (NULL_TREE, ptr_type_node,  
					void_list_node));
    function_decl = build_decl (FUNCTION_DECL,  
				get_identifier ("__objc_execClass"),  
				function_type);
    DECL_EXTERNAL (function_decl) = 1;
    TREE_PUBLIC (function_decl) = 1;
    pushdecl (function_decl);
    rest_of_decl_compilation (function_decl, 0, 0, 0);

    parms
      = build_tree_list (NULLT,
			 build_unary_op (ADDR_EXPR, _OBJC_MODULES_decl, 0));
    decelerator = build_function_call (function_decl, parms);

    /* void __objc_file_init () {objc_execClass(&L_OBJC_MODULES);}  */

    start_function (void_list_node,
		    build_parse_node (CALL_EXPR, get_identifier (buf),
				      /* This has the format of the output
					 of get_parm_info.  */
				      tree_cons (NULL_TREE, NULL_TREE,
						 void_list_node),
				      NULL_TREE),
		    0, 0);
#if 0 /* This should be turned back on later
	 for the systems where collect is not needed.  */
    /* Make these functions nonglobal
       so each file can use the same name.  */
    TREE_PUBLIC (current_function_decl) = 0;
#endif
    TREE_USED (current_function_decl) = 1;
    store_parm_decls ();

    assemble_external (function_decl);
    c_expand_expr_stmt (decelerator);

    finish_function (0);

    /* Return the name of the constructor function.  */
    return buf;
  }
#else /* NEXT_OBJC_RUNTIME */
  return 0;
#endif /* NEXT_OBJC_RUNTIME */
}

/* extern const char _OBJC_STRINGS[]; */

static void
generate_forward_declaration_to_string_table ()
{
  tree sc_spec, decl_specs, expr_decl;

  sc_spec = tree_cons (NULLT, ridpointers[(int) RID_EXTERN], NULLT);
  decl_specs = tree_cons (NULLT, ridpointers[(int) RID_CHAR], sc_spec);

  expr_decl = build_nt (ARRAY_REF, get_identifier ("_OBJC_STRINGS"), NULLT);

  _OBJC_STRINGS_decl = define_decl (expr_decl, decl_specs);
}

/* static char _OBJC_STRINGS[] = "..."; */

static void
build_message_selector_pool ()
{
  tree sc_spec, decl_specs, expr_decl;
  tree chain, string_expr;
  int goolengthtmp = 0, msg_pool_size = 0;
  char *string_goo;

  sc_spec = tree_cons (NULLT, ridpointers[(int) RID_STATIC], NULLT);
  decl_specs = tree_cons (NULLT, ridpointers[(int) RID_CHAR], sc_spec);

  expr_decl = build_nt (ARRAY_REF, get_identifier ("_OBJC_STRINGS"), NULLT);

  _OBJC_STRINGS_decl = start_decl (expr_decl, decl_specs, 1);

  for (chain = sel_refdef_chain; chain; chain = TREE_CHAIN (chain))
    msg_pool_size += IDENTIFIER_LENGTH (TREE_VALUE (chain)) + 1;

  msg_pool_size++;

  string_goo = (char *)xmalloc (msg_pool_size);
  bzero (string_goo, msg_pool_size);

  for (chain = sel_refdef_chain; chain; chain = TREE_CHAIN (chain))
    {
      strcpy (string_goo + goolengthtmp, IDENTIFIER_POINTER (TREE_VALUE (chain)));
      goolengthtmp += IDENTIFIER_LENGTH (TREE_VALUE (chain)) + 1;
    }

  string_expr = my_build_string (msg_pool_size, string_goo);

  finish_decl (_OBJC_STRINGS_decl, string_expr, NULLT);
}

/*
 * synthesize the following expr: (char *)&_OBJC_STRINGS[<offset>]
 *
 * the cast stops the compiler from issuing the following message:
 *
 * grok.m: warning: initialization of non-const * pointer from const *
 * grok.m: warning: initialization between incompatible pointer types
 */
static tree
build_msg_pool_reference (offset)
     int offset;
{
  tree expr = build_int_2 (offset, 0);
  tree cast;

  expr = build_array_ref (_OBJC_STRINGS_decl, expr);
  expr = build_unary_op (ADDR_EXPR, expr, 0);

  cast = build_tree_list (build_tree_list (NULLT, ridpointers[(int) RID_CHAR]),
			  build1 (INDIRECT_REF, NULLT, NULLT));
  TREE_TYPE (expr) = groktypename (cast);
  return expr;
}

#ifndef OBJC_SELECTORS_WITHOUT_LABELS
static tree
build_selector_reference (idx)
      int idx;
{
  tree ref, decl, name, ident;
  char buf[256];
  struct obstack *save_current_obstack = current_obstack;
  struct obstack *save_rtl_obstack = rtl_obstack;

  sprintf (buf, "_OBJC_SELECTOR_REFERENCES_%d", idx);

  /* new stuff */
  rtl_obstack = current_obstack = &permanent_obstack;
  ident = get_identifier (buf);

  if (IDENTIFIER_GLOBAL_VALUE (ident))
    decl = IDENTIFIER_GLOBAL_VALUE (ident); /* set by pushdecl() */
  else 
    {
      decl = build_decl (VAR_DECL, ident, selector_type);
      DECL_EXTERNAL (decl) = 1;
      TREE_PUBLIC (decl) = 1;
      TREE_USED (decl) = 1;
  
      make_decl_rtl (decl, 0, 1); /* usually called from `rest_of_decl_compilation' */
      pushdecl_top_level (decl);  /* our `extended/custom' pushdecl in c-decl.c */
    }
  current_obstack = save_current_obstack;
  rtl_obstack = save_rtl_obstack;

  return decl;
}
#endif

static tree
init_selector (offset)
     int offset;
{
  tree expr = build_msg_pool_reference (offset);
  TREE_TYPE (expr) = selector_type; /* cast */
  return expr;
}

static void
build_selector_translation_table ()
{
  tree sc_spec, decl_specs, expr_decl;
  tree chain, initlist = NULLT;
  int offset = 0;
#ifndef OBJC_SELECTORS_WITHOUT_LABELS
  tree decl, var_decl;
  int idx = 0;
  char buf[256];
#else
  /* The corresponding pop_obstacks is in finish_decl,
     called at the end of this function.  */
  push_obstacks_nochange ();
#endif

  for (chain = sel_ref_chain; chain; chain = TREE_CHAIN (chain))
    {
      tree expr;

#ifndef OBJC_SELECTORS_WITHOUT_LABELS
      sprintf (buf, "_OBJC_SELECTOR_REFERENCES_%d", idx);
      sc_spec = build_tree_list (NULLT, ridpointers[(int) RID_STATIC]);

      /* static SEL _OBJC_SELECTOR_REFERENCES_n = ...; */
      decl_specs = tree_cons (NULLT, selector_type, sc_spec);
      var_decl = get_identifier (buf);

      /* the `decl' that is returned from start_decl is the one that we
	* forward declared in `build_selector_reference()'
	*/
      decl = start_decl (var_decl, decl_specs, 1); 
#endif

      expr = init_selector (offset);

      /* add one for the '\0' character */
      offset += IDENTIFIER_LENGTH (TREE_VALUE (chain)) + 1;

#ifndef OBJC_SELECTORS_WITHOUT_LABELS
      finish_decl (decl, expr, NULLT);
      idx++;
#else
      initlist = tree_cons (NULLT, expr, initlist);
#endif
    }

#ifdef OBJC_SELECTORS_WITHOUT_LABELS
  /* Cause the variable and its initial value to be actually output.  */
  DECL_EXTERNAL (_OBJC_SELECTOR_REFERENCES_decl) = 0;
  TREE_STATIC (_OBJC_SELECTOR_REFERENCES_decl) = 1;
  /* NULL terminate the list and fix the decl for output. */
  initlist = tree_cons (NULLT, build_int_2 (0, 0), initlist);
  DECL_INITIAL (_OBJC_SELECTOR_REFERENCES_decl) = (tree) 1;
  initlist = build_nt (CONSTRUCTOR, NULLT, nreverse (initlist));
  finish_decl (_OBJC_SELECTOR_REFERENCES_decl, initlist, NULLT);
#endif
}

static void
add_class_reference (ident)
     tree ident;
{
  tree chain;

  if (chain = cls_ref_chain)
    {
      tree tail;
      do
        {
	  if (ident == TREE_VALUE (chain))
	    return;

	  tail = chain;
	  chain = TREE_CHAIN (chain);
        }
      while (chain);

      /* append to the end of the list */
      TREE_CHAIN (tail) = perm_tree_cons (NULLT, ident, NULLT);
    }
  else
    cls_ref_chain = perm_tree_cons (NULLT, ident, NULLT);
}

/*
 * sel_ref_chain is a list whose "value" fields will be instances of
 * identifier_node that represent the selector.
 */
static int
add_selector_reference (ident)
     tree ident;
{
  tree chain;
  int index = 0;

  /* this adds it to sel_refdef_chain, the global pool of selectors */
  add_objc_string (ident);

  if (chain = sel_ref_chain)
    {
      tree tail;
      do
        {
	  if (ident == TREE_VALUE (chain))
	    return index;

	  index++;
	  tail = chain;
	  chain = TREE_CHAIN (chain);
        }
      while (chain);

      /* append to the end of the list */
      TREE_CHAIN (tail) = perm_tree_cons (NULLT, ident, NULLT);
    }
  else
    sel_ref_chain = perm_tree_cons (NULLT, ident, NULLT);

  max_selector_index++;
  return index;
}

/*
 * sel_refdef_chain is a list whose "value" fields will be instances of
 * identifier_node that represent the selector. It returns the offset of
 * the selector from the beginning of the _OBJC_STRINGS pool. This offset
 * is typically used by "init_selector ()" during code generation.
 */
static int
add_objc_string (ident)
     tree ident;
{
  tree chain;
  int offset = 0;

  if (chain = sel_refdef_chain)
    {
      tree tail;
      do
        {
	  if (ident == TREE_VALUE (chain))
	    return offset;

	  /* add one for the '\0' character */
	  offset += IDENTIFIER_LENGTH (TREE_VALUE (chain)) + 1;
	  tail = chain;
	  chain = TREE_CHAIN (chain);
        }
      while (chain);

      /* append to the end of the list */
      TREE_CHAIN (tail) = perm_tree_cons (NULLT, ident, NULLT);
    }
  else
    sel_refdef_chain = perm_tree_cons (NULLT, ident, NULLT);

  return offset;
}

tree
lookup_interface (ident)
     tree ident;
{
  tree chain;

  for (chain = interface_chain; chain; chain = TREE_CHAIN (chain))
    {
      if (ident == CLASS_NAME (chain))
	return chain;
    }
  return NULLT;
}

static tree
objc_copy_list (list, head)
     tree list;
     tree *head;
{
  tree newlist = NULL_TREE, tail = NULL_TREE;

  while (list)
    {
      tail = copy_node (list);

      /* the following statement fixes a bug when inheriting instance
	 variables that are declared to be bitfields. finish_struct () expects
	 to find the width of the bitfield in DECL_INITIAL (), which it
	 nulls out after processing the decl of the super class...rather
	 than change the way finish_struct () works (which is risky),
	 I create the situation it expects...s.naroff (7/23/89).
	 */
      if (DECL_BIT_FIELD (tail) && DECL_INITIAL (tail) == 0)
	DECL_INITIAL (tail) = build_int_2 (DECL_FIELD_SIZE (tail), 0);

      newlist = chainon (newlist, tail);
      list = TREE_CHAIN (list);
    }
  *head = newlist;
  return tail;
}

/* used by:
 * build_private_template (), get_class_ivars (), and get_static_reference ().
 */
static tree
build_ivar_chain (interface)
     tree interface;
{
  tree my_name, super_name, ivar_chain;

  my_name = CLASS_NAME (interface);
  super_name = CLASS_SUPER_NAME (interface);

  /* "leaf" ivars never get copied...there is no reason to. */
  ivar_chain = CLASS_IVARS (interface);

  while (super_name)
    {
      tree op1;
      tree super_interface = lookup_interface (super_name);

      if (!super_interface)
        {
	  /* fatal did not work with 2 args...should fix */
	  error ("Cannot find interface declaration for `%s', superclass of `%s'",
		 IDENTIFIER_POINTER (super_name), IDENTIFIER_POINTER (my_name));
	  exit (34);
        }
      if (super_interface == interface)
        {
          fatal ("Circular inheritance in interface declaration for `%s'",
                 IDENTIFIER_POINTER (super_name));
        }
      interface = super_interface;
      my_name = CLASS_NAME (interface);
      super_name = CLASS_SUPER_NAME (interface);

      op1 = CLASS_IVARS (interface);
      if (op1)
        {
	  tree head, tail = objc_copy_list (op1, &head);

	  /* prepend super class ivars...make a copy of the list, we
	   * do not want to alter the original.
	   */
	  TREE_CHAIN (tail) = ivar_chain;
	  ivar_chain = head;
        }
    }
  return ivar_chain;
}

/*
 *  struct <classname> {
 *    struct objc_class *isa;
 *    ...
 *  };
 */
static tree
build_private_template (class)
     tree class;
{
  tree ivar_context;

  if (CLASS_STATIC_TEMPLATE (class))
    {
      _PRIVATE_record = CLASS_STATIC_TEMPLATE (class);
      ivar_context = TYPE_FIELDS (CLASS_STATIC_TEMPLATE (class));
    }
  else
    {
      _PRIVATE_record = start_struct (RECORD_TYPE, CLASS_NAME (class));

      ivar_context = build_ivar_chain (class);

      finish_struct (_PRIVATE_record, ivar_context);

      CLASS_STATIC_TEMPLATE (class) = _PRIVATE_record;

      /* mark this record as class template - for class type checking */
      TREE_STATIC_TEMPLATE (_PRIVATE_record) = 1;
    }
  instance_type = groktypename (
				build_tree_list (build_tree_list (NULLT, _PRIVATE_record),
						 build1 (INDIRECT_REF, NULLT, NULLT)));
  return ivar_context;
}