* c-tree.h: Forward declare struct c_binding.  Declare
	c_override_bindings_to_false.  Update prototypes.
	(struct lang_identifier): Update comments.  Change fields to be
	struct c_binding *.
	(IDENTIFIER_SYMBOL_VALUE, IDENTIFIER_TAG_VALUE)
	(IDENTIFIER_LABEL_VALUE, C_DECL_INVISIBLE)
	(KEEP_NO, KEEP_YES, KEEP_MAYBE): Delete.
	(C_DECL_IN_EXTERNAL_SCOPE, C_DECL_DECLARED_BUILTIN): New.
	* c-common.h: Update prototypes.
	* c-decl.c (struct c_scope): Update commentary.  Remove names,
	names_last, parms, parms_last, tags, and shadowed fields.  Add
	bindings and depth fields.
	(scope_freelist): Move to more appropriate location.
	(c_print_identifier): Update for changes to struct lang_identifier.
	(objc_mark_locals_volatile): Update for new bindings structures.
	(global_bindings_p): Honor c_override_global_bindings_to_false.
	(pushlevel): Rename to push_scope; take no arguments; use the
	scope_freelist; initialize scope->depth and check for overflow.
	(poplevel): Rename to pop_scope; totally rewritten for new bindings
	structures.
	(diagnose_mismatched_decls): Use C_DECL_DECLARED_BUILTIN, not
	C_DECL_INVISIBLE, for certain decisions.  Adjust some diagnostics.
	Improve some commentary.  Adjust handling of forward parm decls.
	(merge_decls): Set C_DECL_DECLARED_BUILTIN when appropriate.
	Preserve C_DECL_IN_EXTERNAL_SCOPE.
	(warn_if_shadowing): Correct indentation.  Improve diagnostics.
	(pushdecl): Remove unnecessary assertion.  Short-circuit anonymous
	decls.  Rewrite for new bindings structures.  Improve commentary.
	Eliminate the copy_node call.
	(implicit_decl_warning): Use the "diag" idiom (as seen in
	locate_old_decl) to reduce code duplication; call locate_old_decl
	if appropriate.  Relocate to remove need for forward declaration.
	(implicitly_declare): Adjust for new bindings structures.  Kludge
	around Objective-C not-really-builtin functions.
	(undeclared_variable): Improve diagnostics.  If current_function_decl
	is nonnull but current_function_scope is null, use current_scope.
	Use bind.
	(lookup_tag): Adjust for new bindings structures.  Kludge around
	Objective-C's tag declarations that wind up in the external scope.
	(lookup_name): Adjust for new bindings structures.  Kludge around
	c-common.c's pseudo-typedefs that wind up in the external scope.
	(lookup_name_current_level): Rename lookup_name_in_scope; take a
	second argument indicating the scope to examine; rewrite for
	new bindings structures.
	(c_init_decl_processing): Adjust for renamed functions.  Do not
	initialize current_file_decl, first_builtin_decl, last_builtin_decl.
	First scope pushed is the external scope, not the global scope.
	(builtin_function): Use bind, not pushdecl.  Adjust other bits
	for new data structures.  Keep track of builtins that should be
	made visible automatically.
	(start_decl): Adjust diagnostics.  Remove unnecessary call to
	expand_decl.
	(grokparms): Return 0 if arg_types is error_mark_node.
	(get_parm_info): Rename "void_at_end" argument to "ellipsis", with
	reversed sense.  Rewrite for new bindings structures.  Do not
	leave any decls in the scope, to prevent pop_scope from doing
	contradictory things with them.
	(finish_struct, finish_enum): Remove redundant diagnostics.
	(build_enumerator): Don't cascade diagnostics for error_mark_node.
	Mark location where -pedantic changes the meaning of the program.
	(store_parm_decls_newstyle, store_parm_decls_oldstyle): Load the
	parameter decls into the function's scope structure using bind.
	Warn here about function definitions in the wrong style.
	Adjust diagnostics.
	(store_parm_decls): Correct the determination of whether a
	function was defined with a prototype.
	(c_write_global_declarations): Operate on all file decls and on
	the external scope.  Split body of the loop to...
	(c_write_global_declarations_1): ... this new function, to avoid
	code duplication.
	(truly_local_externals, first_builtin_decl, last_builtin_decl)
	(make_scope, pop_scope, in_parm_level_p, set_block)
	(any_external_decl, record_external_decl, bind_label, getdecls)
	(link_hash_hash, link_hash_eq, merge_translation_unit_decls)
	(c_reset_state): Delete.
	(visible_builtins, c_override_global_bindings_to_false)
	(c_binding, I_SYMBOL_BINDING, I_SYMBOL_DECL, I_TAG_BINDING)
	(I_TAG_DECL, I_LABEL_BINDING, I_LABEL_DECL, file_scope)
	(external_scope, binding_freelist, bind, free_binding_and_advance)
	(push_file_scope, pop_file_scope): New.
	(pushtag, pushdecl_top_level, lookup_label, declare_label)
	(define_label, c_make_fname_decl, finish_decl)
	(mark_forward_parm_decls, build_compound_literal)
	(grokdeclarator, start_function, check_for_loop_decls)
	(identifier_global_value, record_builtin_type): Minor adjustments
	for new bindings structures.  Improve diagnostics and commentary.
	* c-objc-common.c (start_cdtor, finish_cdtor): Adjust calls to
	pushlevel/poplevel respectively.
	(c_objc_common_finish_file): Don't call merge_translation_unit_decls.
	* c-opts.c (c_common_parse_file): Remove spurious ATTRIBUTE_UNUSED.
	Warn about YYDEBUG not being defined only if -dy.  Remove no-longer-
	correct loop over multiple translation units; call fatal_error if
	requested to compile more than one file at once.  (This disables
	IMA temporarily - an up-front error being preferable to a crash.)
	* c-parse.in (pushlevel, poplevel rules): Rename push_scope, pop_scope.
	(all actions): Adjust calls to pushlevel/poplevel.
	(parsing_iso_function_signature): Delete.
	(extdef_1): Fold into extdef.
	(old_style_parm_decls_1): Fold into old_style_parm_decls.  Don't
	warn here about function definitions in the wrong style.
	(after_tyle_declarator, parm_declarator_starttypename)
	(parm_declarator_nostarttypename, notype_declarator): Remove
	commented-out productions.
	(parmlist_1, parmlist_2): Use make_node, not tree_cons, to create
	an empty TREE_LIST node.  Adjust calls to get_parm_info.
	(parmlist_2 : ELLIPSIS): Tag the arg-info block with error_mark_node
	to suppress -Wold-style-definition after this error.
	(c_parse_file): Don't clear the binding stack or call
	finish_fname_decls here.  Correct comment.
	* c-typeck.c (same_translation_unit_p): Export.
	(common_type): Use c_override_global_bindings_to_false, not
	pushlevel/poplevel/declare_parm_level.
	* c-lang.c: Override LANG_HOOKS_CLEAR_BINDING_STACK,
	LANG_HOOKS_PUSHLEVEL, LANG_HOOKS_POPLEVEL, LANG_HOOKS_SET_BLOCK,
	and LANG_HOOKS_GETDECLS with do-nothing stubs.
	* objc/objc-lang.c: Likewise.
	* objc/objc-act.c: Adjust all calls to pushlevel, poplevel,
	get_parm_info.
	(OBJC_VOID_AT_END): Delete; replace all uses
	with void_list_node.
	(generate_forward_declaration_to_string_table): Delete.
	* objc/objc-act.h (OCTI_STRG_DECL, UOBJC_STRINGS_decl): Delete.

	* coverage.c (create_coverage): Don't pushdecl anything.
	* langhooks.c (lhd_clear_binding_stack): Call
	lang_hooks.decls.poplevel, not poplevel.
	* tree.c (list_length): If ENABLE_TREE_CHECKING, abort on a
	circular list rather than going into an infinite loop.

cp:
	* cp-lang.c (c_reset_state): Delete.
	(push_file_scope, pop_file_scope): New stubs.
	* parser.c (c_parse_file): Call sorry() here if called more than once.

testsuite:
	* gcc.dg/Wold-style-definition-1.c, gcc.dg/builtins-30.c
	* gcc.dg/unused-4.c, gcc.dg/noncompile/label-1.c
	* gcc.dg/noncompile/label-lineno-1.c, objc.dg/naming-1.m:
	Adjust error regexps.
	* gcc.dg/Wshadow-2.c, gcc.dg/noncompile/incomplete-3.c
	* gcc.dg/noncompile/undeclared-1.c: New test cases.
	* gcc.dg/decl-5.c, gcc.dg/redecl-1.c: Remove XFAIL.
	* gcc.dg/local1.c: Add explanatory comment.

From-SVN: r79883