decl2.c

gcc库的原代码,对编程有很大帮助.

      if (TREE_CHAIN (lengths))
	error ("multiple length specifiers");
      type_id = ridpointers[(int)RID_INT];
      declspecs = chainon (lengths, quals);
    }
  else if (quals)
    {
      error ("no type given, defaulting to `operator int ...'");
      type_id = ridpointers[(int)RID_INT];
      declspecs = quals;
    }
  else
    return NULL_TREE;

 found:
  decl = grokdeclarator (build_parse_node (CALL_EXPR, type_id, parmlist, NULL_TREE),
			 declspecs, FIELD, 0, NULL_TREE, NULL_TREE);
  if (decl == NULL_TREE)
    return NULL_TREE;

  if (TREE_CODE (decl) == FUNCTION_DECL && DECL_CHAIN (decl) != NULL_TREE)
    {
      /* Need a fresh node here so that we don't get circularity
	 when we link these together.  */
      decl = copy_node (decl);
    }

  if (decl == void_type_node
      || (TREE_CODE (decl) == FUNCTION_DECL
	  && TREE_CODE (TREE_TYPE (decl)) != METHOD_TYPE))
    /* bunch of friends.  */
    return decl;

  if (DECL_IN_AGGR_P (decl))
    {
      cp_error ("`%D' already defined in the class ", decl);
      return void_type_node;
    }

  cp_finish_decl (decl, NULL_TREE, NULL_TREE, 0, 0);

  /* If this declaration is common to another declaration
     complain about such redundancy, and return NULL_TREE
     so that we don't build a circular list.  */
  if (DECL_CHAIN (decl))
    {
      cp_error ("function `%D' declared twice in class %T", decl,
		  DECL_CONTEXT (decl));
      return NULL_TREE;
    }
  DECL_IN_AGGR_P (decl) = 1;
  return decl;
}
#endif

tree
grokoptypename (declspecs, declarator)
     tree declspecs, declarator;
{
  tree t = grokdeclarator (declarator, declspecs, TYPENAME, 0,
			   NULL_TREE, NULL_TREE);
  return build_typename_overload (t);
}

/* When a function is declared with an initializer,
   do the right thing.  Currently, there are two possibilities:

   class B
   {
    public:
     // initialization possibility #1.
     virtual void f () = 0;
     int g ();
   };
   
   class D1 : B
   {
    public:
     int d1;
     // error, no f ();
   };
   
   class D2 : B
   {
    public:
     int d2;
     void f ();
   };
   
   class D3 : B
   {
    public:
     int d3;
     // initialization possibility #2
     void f () = B::f;
   };

*/

int
copy_assignment_arg_p (parmtype, virtualp)
     tree parmtype;
     int virtualp;
{
  if (TREE_CODE (parmtype) == REFERENCE_TYPE)
    parmtype = TREE_TYPE (parmtype);

  if ((TYPE_MAIN_VARIANT (parmtype) == current_class_type)
      || (virtualp && DERIVED_FROM_P (parmtype, current_class_type)))
    return 1;

  return 0;
}

static void
grok_function_init (decl, init)
     tree decl;
     tree init;
{
  /* An initializer for a function tells how this function should
     be inherited.  */
  tree type = TREE_TYPE (decl);

  if (TREE_CODE (type) == FUNCTION_TYPE)
    cp_error ("initializer specified for non-member function `%D'", decl);
  else if (DECL_VINDEX (decl) == NULL_TREE)
    cp_error ("initializer specified for non-virtual method `%D'", decl);
  else if (integer_zerop (init))
    {
#if 0
      /* Mark this function as being "defined".  */
      DECL_INITIAL (decl) = error_mark_node;
      /* pure virtual destructors must be defined. */
      /* pure virtual needs to be defined (as abort) only when put in 
	 vtbl. For wellformed call, it should be itself. pr4737 */
      if (!DESTRUCTOR_NAME_P (DECL_ASSEMBLER_NAME (decl)))
	{
	  extern tree abort_fndecl;
	  /* Give this node rtl from `abort'.  */
	  DECL_RTL (decl) = DECL_RTL (abort_fndecl);
	}
#endif
      DECL_ABSTRACT_VIRTUAL_P (decl) = 1;
      if (DECL_NAME (decl) == ansi_opname [(int) MODIFY_EXPR])
	{
	  tree parmtype
	    = TREE_VALUE (TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl))));

	  if (copy_assignment_arg_p (parmtype, 1))
	    TYPE_HAS_ABSTRACT_ASSIGN_REF (current_class_type) = 1;
	}
    }
  else if (TREE_CODE (init) == OFFSET_REF
	   && TREE_OPERAND (init, 0) == NULL_TREE
	   && TREE_CODE (TREE_TYPE (init)) == METHOD_TYPE)
    {
      tree basetype = DECL_CLASS_CONTEXT (init);
      tree basefn = TREE_OPERAND (init, 1);
      if (TREE_CODE (basefn) != FUNCTION_DECL)
	cp_error ("non-method initializer invalid for method `%D'", decl);
      else if (! BINFO_OFFSET_ZEROP (TYPE_BINFO (DECL_CLASS_CONTEXT (basefn))))
	sorry ("base member function from other than first base class");
      else
	{
	  tree binfo = get_binfo (basetype, TYPE_METHOD_BASETYPE (type), 1);
	  if (binfo == error_mark_node)
	    ;
	  else if (binfo == 0)
	    error_not_base_type (TYPE_METHOD_BASETYPE (TREE_TYPE (init)),
				 TYPE_METHOD_BASETYPE (type));
	  else
	    {
	      /* Mark this function as being defined,
		 and give it new rtl.  */
	      DECL_INITIAL (decl) = error_mark_node;
	      DECL_RTL (decl) = DECL_RTL (basefn);
	    }
	}
    }
  else
    cp_error ("invalid initializer for virtual method `%D'", decl);
}

/* When we get a declaration of the form

   type cname::fname ...

   the node for `cname::fname' gets built here in a special way.
   Namely, we push into `cname's scope.  When this declaration is
   processed, we pop back out.  */
tree
build_push_scope (cname, name)
     tree cname;
     tree name;
{
  extern int current_class_depth;
  tree ctype, rval;
  int is_ttp = 0;

  if (cname == error_mark_node)
    return error_mark_node;

  ctype = IDENTIFIER_TYPE_VALUE (cname);

  if (TREE_CODE (ctype) == TEMPLATE_TYPE_PARM)
    is_ttp = 1;
  else if (ctype == NULL_TREE || ! IS_AGGR_TYPE (ctype))
    {
      cp_error ("`%T' not defined as aggregate type", cname);
      return name;
    }
  else if (IS_SIGNATURE (ctype))
    {
      error ("cannot push into signature scope, scope resolution operator ignored");
      return name;
    }

  rval = build_parse_node (SCOPE_REF, cname, name);

  /* Don't need to push the scope if we're already in it.
     We also don't need to push the scope for a ptr-to-member/method.  */

  if (ctype == current_class_type || TREE_CODE (name) != IDENTIFIER_NODE
      || is_ttp)
    return rval;

  /* We do need to push the scope in this case, since CTYPE helps
     determine subsequent initializers (i.e., Foo::Bar x = foo_enum_1;).  */

  push_nested_class (ctype, 3);
  TREE_COMPLEXITY (rval) = current_class_depth;
  return rval;
}

void
cplus_decl_attributes (decl, attributes, prefix_attributes)
     tree decl, attributes, prefix_attributes;
{
  if (decl == NULL_TREE || decl == void_type_node)
    return;

  if (TREE_CODE (decl) == TEMPLATE_DECL)
    decl = DECL_TEMPLATE_RESULT (decl);

  decl_attributes (decl, attributes, prefix_attributes);

  if (TREE_CODE (decl) == TYPE_DECL)
    SET_IDENTIFIER_TYPE_VALUE (DECL_NAME (decl), TREE_TYPE (decl));
}

/* CONSTRUCTOR_NAME:
   Return the name for the constructor (or destructor) for the
   specified class.  Argument can be RECORD_TYPE, TYPE_DECL, or
   IDENTIFIER_NODE.  When given a template, this routine doesn't
   lose the specialization.  */
tree
constructor_name_full (thing)
     tree thing;
{
  if (TREE_CODE (thing) == UNINSTANTIATED_P_TYPE)
    return DECL_NAME (UPT_TEMPLATE (thing));
  if (IS_AGGR_TYPE_CODE (TREE_CODE (thing)))
    {
      if (TYPE_WAS_ANONYMOUS (thing) && TYPE_HAS_CONSTRUCTOR (thing))
	thing = DECL_NAME (TREE_VEC_ELT (TYPE_METHODS (thing), 0));
      else
	thing = TYPE_NAME (thing);
    }
  if (TREE_CODE (thing) == TYPE_DECL
      || (TREE_CODE (thing) == TEMPLATE_DECL
	  && DECL_TEMPLATE_IS_CLASS (thing)))
    thing = DECL_NAME (thing);
  my_friendly_assert (TREE_CODE (thing) == IDENTIFIER_NODE, 197);
  return thing;
}

/* CONSTRUCTOR_NAME:
   Return the name for the constructor (or destructor) for the
   specified class.  Argument can be RECORD_TYPE, TYPE_DECL, or
   IDENTIFIER_NODE.  When given a template, return the plain
   unspecialized name.  */
tree
constructor_name (thing)
     tree thing;
{
  tree t;
  thing = constructor_name_full (thing);
  t = IDENTIFIER_TEMPLATE (thing);
  if (!t)
    return thing;
  t = TREE_PURPOSE (t);
  return DECL_NAME (t);
}

/* Cache the value of this class's main virtual function table pointer
   in a register variable.  This will save one indirection if a
   more than one virtual function call is made this function.  */
void
setup_vtbl_ptr ()
{
  extern tree base_init_expr;

  if (base_init_expr == 0
      && DECL_CONSTRUCTOR_P (current_function_decl))
    emit_base_init (current_class_type, 0);
}

/* Record the existence of an addressable inline function.  */
void
mark_inline_for_output (decl)
     tree decl;
{
  decl = DECL_MAIN_VARIANT (decl);
  if (DECL_SAVED_INLINE (decl))
    return;
  my_friendly_assert (TREE_PERMANENT (decl), 363);
  DECL_SAVED_INLINE (decl) = 1;
#if 0
  if (DECL_PENDING_INLINE_INFO (decl) != 0
      && ! DECL_PENDING_INLINE_INFO (decl)->deja_vu)
    {
      struct pending_inline *t = pending_inlines;
      my_friendly_assert (DECL_SAVED_INSNS (decl) == 0, 198);
      while (t)
	{
	  if (t == DECL_PENDING_INLINE_INFO (decl))
	    break;
	  t = t->next;
	}
      if (t == 0)
	{
	  t = DECL_PENDING_INLINE_INFO (decl);
	  t->next = pending_inlines;
	  pending_inlines = t;
	}
      DECL_PENDING_INLINE_INFO (decl) = 0;
    }
#endif
  saved_inlines = perm_tree_cons (NULL_TREE, decl, saved_inlines);
}

void
clear_temp_name ()
{
  temp_name_counter = 0;
}

/* Hand off a unique name which can be used for variable we don't really
   want to know about anyway, for example, the anonymous variables which
   are needed to make references work.  Declare this thing so we can use it.
   The variable created will be of type TYPE.

   STATICP is nonzero if this variable should be static.  */

tree
get_temp_name (type, staticp)
     tree type;
     int staticp;
{
  char buf[sizeof (AUTO_TEMP_FORMAT) + 20];
  tree decl;
  int toplev = toplevel_bindings_p ();

  push_obstacks_nochange ();
  if (toplev || staticp)
    {
      end_temporary_allocation ();
      sprintf (buf, AUTO_TEMP_FORMAT, global_temp_name_counter++);
      decl = pushdecl_top_level (build_decl (VAR_DECL, get_identifier (buf), type));
    }
  else
    {
      sprintf (buf, AUTO_TEMP_FORMAT, temp_name_counter++);
      decl = pushdecl (build_decl (VAR_DECL, get_identifier (buf), type));
    }
  TREE_USED (decl) = 1;
  TREE_STATIC (decl) = staticp;

  /* If this is a local variable, then lay out its rtl now.
     Otherwise, callers of this function are responsible for dealing
     with this variable's rtl.  */
  if (! toplev)
    {
      expand_decl (decl);
      expand_decl_init (decl);
    }
  pop_obstacks ();

  return decl;
}

/* Get a variable which we can use for multiple assignments.
   It is not entered into current_binding_level, because
   that breaks things when it comes time to do final cleanups
   (which take place "outside" the binding contour of the function).  */
tree
get_temp_regvar (type, init)
     tree type, init;
{
  static char buf[sizeof (AUTO_TEMP_FORMAT) + 20] = { '_' };
  tree decl;

  sprintf (buf+1, AUTO_TEMP_FORMAT, temp_name_counter++);
  decl = build_decl (VAR_DECL, get_identifier (buf), type);
  TREE_USED (decl) = 1;
  DECL_REGISTER (decl) = 1;

  if (init)
    store_init_value (decl, init);

  /* We can expand these without fear, since they cannot need
     constructors or destructors.  */
  expand_decl (decl);
  expand_decl_init (decl);

  if (type_needs_gc_entry (type))
    DECL_GC_OFFSET (decl) = size_int (++current_function_obstack_index);

  return decl;
}

/* Make the macro TEMP_NAME_P available to units which do not
   include c-tree.h.  */
int
temp_name_p (decl)
     tree decl;
{
  return TEMP_NAME_P (decl);
}

/* Finish off the processing of a UNION_TYPE structure.
   If there are static members, then all members are
   static, and must be laid out together.  If the
   union is an anonymous union, we arrange for that
   as well.  PUBLIC_P is nonzero if this union is
   not declared static.  */
void
finish_anon_union (anon_union_decl)
     tree anon_union_decl;
{
  tree