class.c

gcc-2.95.3 Linux下最常用的C编译器

/* Functions related to building classes and their related objects.
   Copyright (C) 1996, 97-98, 1999 Free Software Foundation, Inc.

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.

Java and all Java-based marks are trademarks or registered trademarks
of Sun Microsystems, Inc. in the United States and other countries.
The Free Software Foundation is independent of Sun Microsystems, Inc.  */

/* Written by Per Bothner <[e-mail]> */

#include "config.h"
#include "system.h"
#include "tree.h"
#include "rtl.h"
#include "flags.h"
#include "java-tree.h"
#include "jcf.h"
#include "obstack.h"
#include "toplev.h"
#include "output.h"
#include "parse.h"

static tree mangle_class_field PROTO ((tree class));
static tree make_method_value PROTO ((tree));
static tree build_java_method_type PROTO ((tree, tree, int));
static int32 hashUtf8String PROTO ((const char *, int));
static tree make_field_value PROTO ((tree));
static tree get_dispatch_vector PROTO ((tree));
static tree get_dispatch_table PROTO ((tree, tree));
static void append_gpp_mangled_type PROTO ((struct obstack *, tree));
static tree mangle_static_field PROTO ((tree));

static rtx registerClass_libfunc;

extern struct obstack permanent_obstack;
extern struct obstack temporary_obstack;

/* Return an IDENTIFIER_NODE the same as (OLD_NAME, OLD_LENGTH).
   except that characters matching OLD_CHAR are substituted by NEW_CHAR.
   Also, PREFIX is prepended, and SUFFIX is appended. */

tree
ident_subst (old_name, old_length, prefix, old_char, new_char, suffix)
     const char* old_name;
     int old_length;
     const char *prefix;
     int old_char;
     int new_char;
     const char *suffix;
{
  int prefix_len = strlen (prefix);
  int suffix_len = strlen (suffix);
  int i = prefix_len + old_length + suffix_len + 1;
#ifdef __GNUC__
  char buffer[i];
#else
  char *buffer = (char *)alloca  (i);
#endif
  strcpy (buffer, prefix);
  for (i = 0; i < old_length; i++)
    {
      char ch = old_name[i];
      if (ch == old_char)
	ch = new_char;
      buffer[prefix_len + i] = ch;
    }
  strcpy (buffer + prefix_len + old_length, suffix);
  return get_identifier (buffer);
}

/* Return an IDENTIFIER_NODE the same as OLD_ID,
   except that characters matching OLD_CHAR are substituted by NEW_CHAR.
   Also, PREFIX is prepended, and SUFFIX is appended. */

tree
identifier_subst (old_id, prefix, old_char, new_char, suffix)
     const tree old_id;
     const char *prefix;
     int old_char;
     int new_char;
     const char *suffix;
{
  return ident_subst (IDENTIFIER_POINTER (old_id), IDENTIFIER_LENGTH (old_id),
		      prefix, old_char, new_char, suffix);
}

/* Generate a valid C identifier from the name of the class TYPE,
   prefixed by PREFIX. */

tree
mangled_classname (prefix, type)
  const char *prefix;
  tree type;
{
  tree ident = TYPE_NAME (type);
  if (TREE_CODE (ident) != IDENTIFIER_NODE)
    ident = DECL_NAME (ident);
  return identifier_subst (ident, prefix, '.', '_', "");
}

tree
make_class ()
{
  tree type;
  push_obstacks (&permanent_obstack, &permanent_obstack);
  type = make_node (RECORD_TYPE);
#ifdef JAVA_USE_HANDLES
  tree field1 = build_decl (FIELD_DECL, get_identifier ("obj"),
			    build_pointer_type (type));
  tree field2 = build_decl (FIELD_DECL, get_identifier ("methods"),
			    methodtable_ptr_type);
  tree handle_type = make_node (RECORD_TYPE);
  TREE_CHAIN (field1) = field2;
  TYPE_FIELDS (handle_type) = field1;
  TYPE_BINFO (type) = make_tree_vec (7);
  TYPE_BINFO (handle_type) = make_tree_vec (7);
  BINFO_HANDLE (TYPE_BINFO (handle_type)) = type;
  BINFO_HANDLE (TYPE_BINFO (type)) = handle_type;
#else
  TYPE_BINFO (type) = make_tree_vec (6);
#endif
  pop_obstacks ();

  return type;
}

/* Given a fully-qualified classname in NAME (whose length is NAME_LENGTH),
   and where each of the constituents is separated by '/',
   return a corresponding IDENTIFIER_NODE, except using '.' as separator. */

tree
unmangle_classname (name, name_length)
     const char *name;  int name_length;
{
  tree to_return = ident_subst (name, name_length, "", '/', '.', "");
  /* It's not sufficient to compare to_return and get_identifier
     (name) to determine whether to_return is qualified. There are
     cases in signature analysis where name will be stripped of a
     trailing ';'. */
  name = IDENTIFIER_POINTER (to_return);
  while (*name)
    if (*name++ == '.') 
      {
	QUALIFIED_P (to_return) = 1;
	break;
      }
  
  return to_return;
}

tree
push_class (class_type, class_name)
     tree class_type, class_name;
{
  tree decl, signature;
  char *save_input_filename = input_filename;
  int save_lineno = lineno;
  tree source_name = identifier_subst (class_name, "", '.', '/', ".java");
  push_obstacks (&permanent_obstack, &permanent_obstack);
  CLASS_P (class_type) = 1;
  input_filename = IDENTIFIER_POINTER (source_name);
  lineno = 0;
  decl = build_decl (TYPE_DECL, class_name, class_type);
  input_filename = save_input_filename;
  lineno = save_lineno;
  signature = identifier_subst (class_name, "L", '.', '/', ";");
  IDENTIFIER_SIGNATURE_TYPE (signature) = build_pointer_type (class_type);

  /* Setting DECL_ARTIFICAL forces dbxout.c to specific the type is
     both a typedef and in the struct name-space.  We may want to re-visit
     this later, but for now it reduces the changes needed for gdb. */
  DECL_ARTIFICIAL (decl) = 1;

  pushdecl_top_level (decl);
#ifdef JAVA_USE_HANDLES
  {
    tree handle_name = identifier_subst (class_name,
					 "Handle$", '.', '.', "");
    tree handle_decl = build_decl (TYPE_DECL, handle_name,
				   CLASS_TO_HANDLE_TYPE (class_type));
    pushdecl (handle_decl);
  }
#endif

  pop_obstacks ();
  return decl;
}

/* Finds the (global) class named NAME.  Creates the class if not found.
   Also creates associated TYPE_DECL.
   Does not check if the class actually exists, load the class,
   fill in field or methods, or do layout_type. */

tree
lookup_class (name)
     tree name;
{
  tree decl = IDENTIFIER_CLASS_VALUE (name);
  if (decl == NULL_TREE)
    decl = push_class (make_class (), name);
  return TREE_TYPE (decl);
}

void
set_super_info (access_flags, this_class, super_class, interfaces_count)
     int access_flags;
     tree this_class;
     tree super_class;
     int interfaces_count;
{
  int total_supers = interfaces_count;
  tree class_decl = TYPE_NAME (this_class);
  if (super_class)
    total_supers++;

  push_obstacks (&permanent_obstack, &permanent_obstack);
  TYPE_BINFO_BASETYPES (this_class) = make_tree_vec (total_supers);
  if (super_class)
    {
      tree super_binfo = make_tree_vec (6);
      BINFO_TYPE (super_binfo) = super_class;
      BINFO_OFFSET (super_binfo) = integer_zero_node;
      TREE_VIA_PUBLIC (super_binfo) = 1;
      TREE_VEC_ELT (BINFO_BASETYPES (TYPE_BINFO (this_class)), 0)
	= super_binfo;
      CLASS_HAS_SUPER (this_class) = 1;
    }
  pop_obstacks ();
  
  if (access_flags & ACC_PUBLIC)    CLASS_PUBLIC (class_decl) = 1;
  if (access_flags & ACC_FINAL)     CLASS_FINAL (class_decl) = 1;
  if (access_flags & ACC_SUPER)     CLASS_SUPER (class_decl) = 1;
  if (access_flags & ACC_INTERFACE) CLASS_INTERFACE (class_decl) = 1;
  if (access_flags & ACC_ABSTRACT)  CLASS_ABSTRACT (class_decl) = 1;
}

/* Return length of inheritance chain of CLAS, where java.lang.Object is 0,
   direct sub-classes of Object are 1, and so on. */

int
class_depth (clas)
     tree clas;
{
  int depth = 0;
  if (! CLASS_LOADED_P (clas))
    load_class (clas, 1);
  while (clas != object_type_node)
    {
      depth++;
      clas = TYPE_BINFO_BASETYPE (clas, 0);
    }
  return depth;
}

/* Return true iff TYPE2 is an interface that extends interface TYPE1 */

int
interface_of_p (type1, type2)
     tree type1, type2;
{
  int n, i;
  tree basetype_vec;

  if (!(basetype_vec = TYPE_BINFO_BASETYPES (type2)))
    return 0;
  n = TREE_VEC_LENGTH (basetype_vec);
  for (i = 0; i < n; i++)
    {
      tree vec_elt = TREE_VEC_ELT (basetype_vec, i);
      if (vec_elt && BINFO_TYPE (vec_elt) == type1)
	return 1;
    }
  for (i = 0; i < n; i++)
    {
      tree vec_elt = TREE_VEC_ELT (basetype_vec, i);
      if (vec_elt && BINFO_TYPE (vec_elt) 
	  && interface_of_p (type1, BINFO_TYPE (vec_elt)))
	return 1;
    }
  return 0;
}

/* Return true iff TYPE1 inherits from TYPE2. */

int
inherits_from_p (type1, type2)
     tree type1, type2;
{
  while (type1 != NULL_TREE && TREE_CODE (type1) == RECORD_TYPE)
    {
      if (type1 == type2)
	return 1;
      type1 = CLASSTYPE_SUPER (type1);
    }
  return 0;
}

static void
add_interface_do (basetype_vec, interface_class, i)
     tree basetype_vec, interface_class;
     int i;
{
  tree interface_binfo = make_tree_vec (6);
  BINFO_TYPE (interface_binfo) = interface_class;
  BINFO_OFFSET (interface_binfo) = integer_zero_node;
  TREE_VIA_VIRTUAL (interface_binfo) = 1;
  TREE_VIA_PUBLIC (interface_binfo) = 1;
  TREE_VEC_ELT (basetype_vec, i) = interface_binfo;
}

/* Add INTERFACE_CLASS to THIS_CLASS iff INTERFACE_CLASS can't be
   found in THIS_CLASS. Returns NULL_TREE upon success, INTERFACE_CLASS
   if attempt is made to add it twice. */

tree
maybe_add_interface (this_class, interface_class)
     tree this_class, interface_class;
{
  tree basetype_vec = TYPE_BINFO_BASETYPES (this_class);
  int i;
  int n = TREE_VEC_LENGTH (basetype_vec);
  for (i = 0; ; i++)
    {
      if (i >= n)
	{
	  error ("internal error - too many interface type");
	  return NULL_TREE;
	}
      else if (TREE_VEC_ELT (basetype_vec, i) == NULL_TREE)
	break;
      else if (BINFO_TYPE (TREE_VEC_ELT (basetype_vec, i)) == interface_class)
	return interface_class;
    } 
  add_interface_do (basetype_vec, interface_class, i);
  return NULL_TREE;
}

/* Add the INTERFACE_CLASS as one of the interfaces of THIS_CLASS. */

void
add_interface (this_class, interface_class)
     tree this_class, interface_class;
{
  tree basetype_vec = TYPE_BINFO_BASETYPES (this_class);
  int i;
  int n = TREE_VEC_LENGTH (basetype_vec);
  for (i = 0; ; i++)
    {
      if (i >= n)
	{
	  error ("internal error - too many interface type");
	  return;
	}
      else if (TREE_VEC_ELT (basetype_vec, i) == NULL_TREE)
	break;
    }
  add_interface_do (basetype_vec, interface_class, i);
}

#if 0
/* Return the address of a pointer to the first FUNCTION_DECL
   in the list (*LIST) whose DECL_NAME is NAME. */

static tree *
find_named_method (list, name)
     tree *list;
     tree name;
{
  while (*list && DECL_NAME (*list) != name)
    list = &TREE_CHAIN (*list);
  return list;
}
#endif

static tree
build_java_method_type (fntype, this_class, access_flags)
     tree fntype;
     tree this_class;
     int access_flags;
{
  if (access_flags & ACC_STATIC)
    return fntype;
  return build_method_type (CLASS_TO_HANDLE_TYPE (this_class), fntype);
}

tree
add_method_1 (handle_class, access_flags, name, function_type)
     tree handle_class;
     int access_flags;
     tree name;
     tree function_type;
{
  tree method_type, fndecl;
  push_obstacks (&permanent_obstack, &permanent_obstack);

  method_type = build_java_method_type (function_type,
					handle_class, access_flags);

  fndecl = build_decl (FUNCTION_DECL, name, method_type);
  DECL_CONTEXT (fndecl) = handle_class;

  DECL_LANG_SPECIFIC (fndecl)
    = (struct lang_decl *) permalloc (sizeof (struct lang_decl));
  bzero ((PTR) DECL_LANG_SPECIFIC (fndecl), sizeof (struct lang_decl));

  TREE_CHAIN (fndecl) = TYPE_METHODS (handle_class);
  TYPE_METHODS (handle_class) = fndecl;
  pop_obstacks ();

  if (access_flags & ACC_PUBLIC) METHOD_PUBLIC (fndecl) = 1;
  if (access_flags & ACC_PROTECTED) METHOD_PROTECTED (fndecl) = 1;
  if (access_flags & ACC_PRIVATE) METHOD_PRIVATE (fndecl) = 1;
  if (access_flags & ACC_NATIVE) METHOD_NATIVE (fndecl) = 1;
  if (access_flags & ACC_STATIC) METHOD_STATIC (fndecl) = 1;
  if (access_flags & ACC_FINAL) METHOD_FINAL (fndecl) = 1;
  if (access_flags & ACC_SYNCHRONIZED) METHOD_SYNCHRONIZED (fndecl) = 1;
  if (access_flags & ACC_ABSTRACT) METHOD_ABSTRACT (fndecl) = 1;
  if (access_flags & ACC_TRANSIENT) METHOD_TRANSIENT (fndecl) = 1;
  return fndecl;
}

/* Add a method to THIS_CLASS.
   The method's name is NAME.
   Its signature (mangled type) is METHOD_SIG (an IDENTIFIER_NODE). */