c-decl.c (struct binding_level): Add shadowed_tags and function_body...

2003-04-10  Zack Weinberg  <zack@codesourcery.com>

	* c-decl.c (struct binding_level): Add shadowed_tags and
	function_body; remove this_block, tag_transparent, and
	subblocks_tag_transparent; update comments.
	(clear_binding_level, lookup_tag_reverse): Kill.
	(make_binding_level): Use ggc_alloc_cleared or memset.
	(lookup_tag): Remove struct binding_level* parameter.  All
	callers changed. Just look at IDENTIFIER_TAG_VALUE, and
	current_binding_level->tags if asked for thislevel_only or if
	we might have to diagnose "struct foo; union foo;"
	(pushlevel): Ignore argument.  Do not push another binding
	level on the transition from the parameters to the top level
	of the function body; just tweak the flags and proceed.
	(poplevel): Overhaul.  Clear IDENTIFIER_TAG_VALUEs; on exiting
	a function body, separate the parameter list from the
	top-level local variables.
	(set_block): Do nothing.
	(pushtag): Set IDENTIFIER_TAG_VALUE and add an entry to
	shadowed_tags if necessary.
	(warn_if_shadowing): Nuke the special case for local shadowing
	parameter.
	(pushdecl): Do not create a shadow entry if we are replacing
	an older decl in the same binding level.
	(pushdecl_function_level): Tweak for new way of indicating
	function scope.
	(shadow_tag_warned): Use TYPE_NAME, not	lookup_tag_reverse.
	(start_function): Don't set subblocks_tag_transparent.
	(finish_function): Fix up the binding_level stack for totally
	empty functions.  Otherwise, don't call poplevel.

	* c-common.c (shadow_warning): MANDATORY argument is no longer
	necessary.  Always use plain warning.
	* c-common.h: Update to match.

	* cfglayout.c (scope_to_insns_initialize): Clear block when we
	hit the FUNCTION_DECL.
	* function.c: Do not create cyclic tree structure.

2003-04-10  Zack Weinberg  <zack@codesourcery.com>

	* c-tree.h (struct lang_identifier): Replace global_value,
	local_value members with symbol_value, tag_value.  Kill
	implicit_decl and limbo_value.
	(IDENTIFIER_GLOBAL_VALUE, IDENTIFIER_LOCAL_VALUE,
	IDENTIFIER_LIMBO_VALUE, IDENTIFIER_IMPLICIT_DECL,
	C_MISSING_PROTOTYPE_WARNED): Kill.
	(IDENTIFIER_SYMBOL_VALUE, IDENTIFIER_TAG_VALUE,
	C_DECL_IMPLICIT, C_DECL_ISNT_PROTOTYPE): New.
	(C_DECL_ANTICIPATED): Rename to C_DECL_INVISIBLE.
	(implicit_decl_warning, lookup_name_current_level,
	record_function_scope_shadow): Don't prototype.
	(pushdecl_function_level): Prototype.

	* c-decl.c (truly_local_externals): New variable.
	(struct binding_level): Adjust commentary.
	(get_function_binding_level, clear_limbo_values,
	record_function_scope_shadow): Kill.
	(lookup_name_current_level, implicit_decl_warning): Are	now static.
	(any_external_decl, record_external_decl): New static functions.
	(clone_underlying type): Split out of pushdecl.
	(c_print_identifier): Update to match changes to struct
	lang_identifier.
	(poplevel): Delete #if 0 block.  Make externals invisible
	instead of clearing their IDENTIFIER_SYMBOL_VALUEs.  Don't
	call clear_limbo_values.  Refer to IDENTIFIER_SYMBOL_VALUE not
	IDENTIFIER_GLOBAL_VALUE or IDENTIFIER_LOCAL_VALUE.
	(duplicate-decls): For real parm decl after a forward decl,
	set TREE_ASM_WRITTEN here.  Allow void foo(...) followed by
	foo(...) { } with only a warning.  Say whether a previous
	declaration was implicit.
	(warn_if_shadowing): Now handles all shadowing, not just
	local-over-local.  Clarify comments.
	(pushdecl): Rewritten.  There is no longer a distinction
	between global and local symbol values; they're all
	IDENTIFIER_SYMBOL_VALUE.  Call record_external_decl on all
	DECL_EXTERNAL decls, and use any_external_decl to check
	against previous externals.  Kill #if 0 blocks.  Don't
	tolerate error_mark_node being NULL.
	(pushdecl_top_level): Handle only those cases which
	Objective C (the only user) needs.
	(pushdecl_function_level): New function.
	(implicitly_declare): Create ordinary decls with
	C_DECL_IMPLICIT set.  Recycle old decls, however they got
	created.
	(lookup_name): It's always IDENTIFIER_SYMBOL_VALUE. Return 0
	for C_DECL_INVISIBLE symbols.
	(lookup_name_current_level): Likewise.  Use chain_member.
	(c_make_fname_decl): Don't muck with DECL_CONTEXT.
	Use pushdecl_function_level.
	(builtin_function): Use C_DECL_INVISIBLE.
	(start_function): Don't muck with IDENTIFIER_IMPLICIT_DECL.
	Use C_DECL_ISNT_PROTOTYPE and C_DECL_IMPLICIT.
	(store_parm_decls): It's IDENTIFIER_SYMBOL_VALUE now.
	(identifier_global_value): Same.  Must scan
	global_binding_level in extremis.

	* c-typeck.c (undeclared_variable): New static function, split
	from build_external_ref.
	(build_external_ref): Use DECL_CONTEXT, not
	IDENTIFIER_LOCAL_VALUE, to decide whether a local hides
	an instance variable.  Restructure for clarity.
	* objc/objc-act.c: Use identifier_global_value, not
	IDENTIFIER_GLOBAL_VALUE.

cp:
	* decl.c: Update all calls to shadow_warning.

testsuite:
	* gcc.c-torture/execute/builtin-noret-2.c: New.
	* gcc.c-torture/execute/builtin-noret-2.x: New.
	XFAIL builtin-noret-2.c at -O1 and above.
	* gcc.dg/redecl.c: New.
	* gcc.dg/Wshadow-1.c: Update error regexps.

From-SVN: r65460

1 files changed, 29 insertions, 37 deletions

diff --git a/gcc/c-tree.h b/gcc/c-tree.h
index 29352f5..368c970 100644
--- a/gcc/c-tree.h
+++ b/gcc/c-tree.h
@@ -1,6 +1,6 @@
 /* Definitions for C parsing and type checking.
    Copyright (C) 1987, 1993, 1994, 1995, 1997, 1998,
-   1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+   1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -37,11 +37,9 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 struct lang_identifier GTY(())
 {
   struct c_common_identifier common_id;
-  tree global_value;
-  tree local_value;
+  tree symbol_value;
+  tree tag_value;
   tree label_value;
-  tree implicit_decl;
-  tree limbo_value;
 };
 
 /* The resulting tree type.  */
@@ -70,26 +68,17 @@ struct lang_decl GTY(())
 /* Macros for access to language-specific slots in an identifier.  */
 /* Each of these slots contains a DECL node or null.  */
 
-/* This represents the value which the identifier has in the
-   file-scope namespace.  */
-#define IDENTIFIER_GLOBAL_VALUE(NODE)	\
-  (((struct lang_identifier *) (NODE))->global_value)
-/* This represents the value which the identifier has in the current
-   scope.  */
-#define IDENTIFIER_LOCAL_VALUE(NODE)	\
-  (((struct lang_identifier *) (NODE))->local_value)
-/* This represents the value which the identifier has as a label in
-   the current label scope.  */
+/* The value of the identifier in the namespace of "ordinary identifiers"
+   (data objects, enum constants, functions, typedefs).  */
+#define IDENTIFIER_SYMBOL_VALUE(NODE)	\
+  (((struct lang_identifier *) (NODE))->symbol_value)
+/* The value of the identifier in the namespace of struct, union,
+   and enum tags.  */
+#define IDENTIFIER_TAG_VALUE(NODE)	\
+  (((struct lang_identifier *) (NODE))->tag_value)
+/* The value of the identifier in the namespace of labels.  */
 #define IDENTIFIER_LABEL_VALUE(NODE)	\
   (((struct lang_identifier *) (NODE))->label_value)
-/* This records the extern decl of this identifier, if it has had one
-   at any point in this compilation.  */
-#define IDENTIFIER_LIMBO_VALUE(NODE)	\
-  (((struct lang_identifier *) (NODE))->limbo_value)
-/* This records the implicit function decl of this identifier, if it
-   has had one at any point in this compilation.  */
-#define IDENTIFIER_IMPLICIT_DECL(NODE)	\
-  (((struct lang_identifier *) (NODE))->implicit_decl)
 
 /* In identifiers, C uses the following fields in a special way:
    TREE_PUBLIC        to record that there was a previous local extern decl.
@@ -129,13 +118,6 @@ struct lang_type GTY(())
 #define C_TYPE_VARIABLE_SIZE(TYPE) TYPE_LANG_FLAG_1 (TYPE)
 #define C_DECL_VARIABLE_SIZE(TYPE) DECL_LANG_FLAG_0 (TYPE)
 
-#if 0 /* Not used.  */
-/* Record whether a decl for a function or function pointer has
-   already been mentioned (in a warning) because it was called
-   but didn't have a prototype.  */
-#define C_MISSING_PROTOTYPE_WARNED(DECL) DECL_LANG_FLAG_2 (DECL)
-#endif
-
 /* Store a value in that field.  */
 #define C_SET_EXP_ORIGINAL_CODE(EXP, CODE) \
   (TREE_COMPLEXITY (EXP) = (int) (CODE))
@@ -147,10 +129,22 @@ struct lang_type GTY(())
    return type.  */
 #define C_FUNCTION_IMPLICIT_INT(EXP) DECL_LANG_FLAG_1 (EXP)
 
-/* Nonzero for a declaration of a built in function if there has been no
-   occasion that would declare the function in ordinary C.
-   Using the function draws a pedantic warning in this case.  */
-#define C_DECL_ANTICIPATED(EXP) DECL_LANG_FLAG_3 (EXP)
+/* For a FUNCTION_DECL, nonzero if it was an implicit declaration.  */
+#define C_DECL_IMPLICIT(EXP) DECL_LANG_FLAG_2 (EXP)
+
+/* Nonzero for a declaration of an external object which is not
+   currently in scope.  This is either a built-in declaration of
+   a library function, before a real declaration has been seen,
+   or a declaration that appeared in an inner scope that has ended.  */
+#define C_DECL_INVISIBLE(EXP) DECL_LANG_FLAG_3 (EXP)
+
+/* Nonzero for a decl which either doesn't exist or isn't a prototype.
+   N.B. Could be simplified if all built-in decls had complete prototypes
+   (but this is presently difficult because some of them need FILE*).  */
+#define C_DECL_ISNT_PROTOTYPE(EXP)			\
+       (EXP == 0					\
+	|| (TYPE_ARG_TYPES (TREE_TYPE (EXP)) == 0	\
+	    && !DECL_BUILT_IN (EXP)))
 
 /* For FUNCTION_TYPE, a hidden list of types of arguments.  The same as
    TYPE_ARG_TYPES for functions with prototypes, but created for functions
@@ -207,11 +201,9 @@ extern tree grokfield                           PARAMS ((const char *, int, tree
 extern tree groktypename                        PARAMS ((tree));
 extern tree groktypename_in_parm_context        PARAMS ((tree));
 extern tree implicitly_declare                  PARAMS ((tree));
-extern void implicit_decl_warning               PARAMS ((tree));
 extern int  in_parm_level_p                     PARAMS ((void));
 extern void keep_next_level                     PARAMS ((void));
 extern tree lookup_name                         PARAMS ((tree));
-extern tree lookup_name_current_level		PARAMS ((tree));
 extern void parmlist_tags_warning               PARAMS ((void));
 extern void pending_xref_error                  PARAMS ((void));
 extern void c_push_function_context             PARAMS ((struct function *));
@@ -220,8 +212,8 @@ extern void pop_label_level                     PARAMS ((void));
 extern void push_label_level                    PARAMS ((void));
 extern void push_parm_decl                      PARAMS ((tree));
 extern tree pushdecl_top_level                  PARAMS ((tree));
+extern tree pushdecl_function_level		PARAMS ((tree, tree));
 extern void pushtag                             PARAMS ((tree, tree));
-extern void record_function_scope_shadow	PARAMS ((tree));
 extern tree set_array_declarator_type           PARAMS ((tree, tree, int));
 extern tree shadow_label                        PARAMS ((tree));
 extern void shadow_tag                          PARAMS ((tree));