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[mainline] C++ PATCH: Tidy name hiding
- From: Gabriel Dos Reis <gdr at integrable-solutions dot net>
- To: gcc-patches at gcc dot gnu dot org
- Cc: mark at codesourcery dot com
- Date: 30 Aug 2003 00:10:09 +0200
- Subject: [mainline] C++ PATCH: Tidy name hiding
- Organization: Integrable Solutions
Mark,
with your recent fix
2003-08-19 Mark Mitchell <mark@codesourcery.com>
PR c++/11036
* cp-tree.h (add_binding): Add prototype.
The comment for add_binding
/* ID is already bound in the current scope. But, DECL is an
additional binding for ID in the same scope. This is the `struct
stat' hack whereby a non-typedef class-name or enum-name can be
bound at the same level as some other kind of entity. It's the
responsibility of the caller to check that inserting this name is
valid here. Returns nonzero if the new binding was successful. */
went a bit out-of-date since the "id" parameter became "binding".
This patch improves on the comment by adding more reference to the
standard. I move it to the name-lookup module, where it belongs to.
(That contributes to splitting cp/decl.c project)
Also, since that function is actually hiding a declaration for a name,
I renamed it to cxx_binding_hide_name.
Finally, as the last comment says, it is the responsability of the
caller to make sure that the hiding is valid. Therefore, there is no
need for issueing a diagnostic. That is supposed to be done by the
caller. In fact, we do issue twice diagnostics about conflicting
declarations in certain circumstances. I came to this while working on
an namespace-alias-definition issue.
Bootstrapped. i'm regtesting an on i686-pc-linux. OK, if it passed?
Thanks,
-- Gaby
Index: ChangeLog
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/ChangeLog,v
retrieving revision 1.3630
diff -p -r1.3630 ChangeLog
*** ChangeLog 29 Aug 2003 07:00:30 -0000 1.3630
--- ChangeLog 29 Aug 2003 21:42:56 -0000
***************
*** 1,3 ****
--- 1,15 ----
+ 2003-08-29 Gabriel Dos Reus <gdr@integrable-solutions.net>
+
+ * cp-tree.h (add_binding): Remove.
+ * name-lookup.c (cxx_binding_hide_name): Rename from add_binding.
+ Improve documentation. Tidy. Don't issue diagnotics.
+ (set_namespace_binding): Adjust call.
+ * name-lookup.c (cxx_binding_hide_name): Declare.
+ * decl.c (add_binding): Move to name-lookup.c.
+ (push_local_binding): Adjust call
+ (push_class_binding): Likewise.
+ (set_identifier_type_value_with_scope): Likewise.
+
2003-08-29 Gabriel Dos Reis <gdr@integrable-solutions.net>
PR c++/11811
Index: cp-tree.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/cp-tree.h,v
retrieving revision 1.907
diff -p -r1.907 cp-tree.h
*** cp-tree.h 25 Aug 2003 15:47:38 -0000 1.907
--- cp-tree.h 29 Aug 2003 21:42:58 -0000
*************** extern void register_dtor_fn
*** 3744,3750 ****
extern tmpl_spec_kind current_tmpl_spec_kind (int);
extern tree cp_fname_init (const char *);
extern tree check_elaborated_type_specifier (enum tag_types, tree, bool);
- extern int add_binding (cxx_binding *, tree);
extern bool have_extern_spec;
/* in decl2.c */
--- 3744,3749 ----
Index: decl.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/decl.c,v
retrieving revision 1.1118
diff -p -r1.1118 decl.c
*** decl.c 26 Aug 2003 09:16:15 -0000 1.1118
--- decl.c 29 Aug 2003 21:43:05 -0000
*************** push_binding (tree id, tree decl, cxx_sc
*** 911,992 ****
IDENTIFIER_BINDING (id) = binding;
}
- /* ID is already bound in the current scope. But, DECL is an
- additional binding for ID in the same scope. This is the `struct
- stat' hack whereby a non-typedef class-name or enum-name can be
- bound at the same level as some other kind of entity. It's the
- responsibility of the caller to check that inserting this name is
- valid here. Returns nonzero if the new binding was successful. */
-
- int
- add_binding (cxx_binding *binding, tree decl)
- {
- tree bval = BINDING_VALUE (binding);
- int ok = 1;
-
- timevar_push (TV_NAME_LOOKUP);
- if (TREE_CODE (decl) == TYPE_DECL && DECL_ARTIFICIAL (decl))
- /* The new name is the type name. */
- BINDING_TYPE (binding) = decl;
- else if (!bval)
- /* This situation arises when push_class_level_binding moves an
- inherited type-binding out of the way to make room for a new
- value binding. */
- BINDING_VALUE (binding) = decl;
- else if (TREE_CODE (bval) == TYPE_DECL && DECL_ARTIFICIAL (bval))
- {
- /* The old binding was a type name. It was placed in
- BINDING_VALUE because it was thought, at the point it was
- declared, to be the only entity with such a name. Move the
- type name into the type slot; it is now hidden by the new
- binding. */
- BINDING_TYPE (binding) = bval;
- BINDING_VALUE (binding) = decl;
- INHERITED_VALUE_BINDING_P (binding) = 0;
- }
- else if (TREE_CODE (bval) == TYPE_DECL
- && TREE_CODE (decl) == TYPE_DECL
- && DECL_NAME (decl) == DECL_NAME (bval)
- && (same_type_p (TREE_TYPE (decl), TREE_TYPE (bval))
- /* If either type involves template parameters, we must
- wait until instantiation. */
- || uses_template_parms (TREE_TYPE (decl))
- || uses_template_parms (TREE_TYPE (bval))))
- /* We have two typedef-names, both naming the same type to have
- the same name. This is OK because of:
-
- [dcl.typedef]
-
- In a given scope, a typedef specifier can be used to redefine
- the name of any type declared in that scope to refer to the
- type to which it already refers. */
- ok = 0;
- /* There can be two block-scope declarations of the same variable,
- so long as they are `extern' declarations. However, there cannot
- be two declarations of the same static data member:
-
- [class.mem]
-
- A member shall not be declared twice in the
- member-specification. */
- else if (TREE_CODE (decl) == VAR_DECL && TREE_CODE (bval) == VAR_DECL
- && DECL_EXTERNAL (decl) && DECL_EXTERNAL (bval)
- && !DECL_CLASS_SCOPE_P (decl))
- {
- duplicate_decls (decl, BINDING_VALUE (binding));
- ok = 0;
- }
- else
- {
- error ("declaration of `%#D'", decl);
- cp_error_at ("conflicts with previous declaration `%#D'",
- BINDING_VALUE (binding));
- ok = 0;
- }
-
- POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, ok);
- }
-
/* Add DECL to the list of things declared in B. */
static void
--- 911,916 ----
*************** push_local_binding (tree id, tree decl,
*** 1040,1046 ****
if (lookup_name_current_level (id))
{
/* Supplement the existing binding. */
! if (!add_binding (IDENTIFIER_BINDING (id), decl))
/* It didn't work. Something else must be bound at this
level. Do not add DECL to the list of things to pop
later. */
--- 964,970 ----
if (lookup_name_current_level (id))
{
/* Supplement the existing binding. */
! if (!cxx_binding_hide_name (IDENTIFIER_BINDING (id), decl))
/* It didn't work. Something else must be bound at this
level. Do not add DECL to the list of things to pop
later. */
*************** push_class_binding (tree id, tree decl)
*** 1079,1085 ****
if (binding && BINDING_SCOPE (binding) == class_binding_level)
/* Supplement the existing binding. */
! result = add_binding (IDENTIFIER_BINDING (id), decl);
else
/* Create a new binding. */
push_binding (id, decl, class_binding_level);
--- 1003,1009 ----
if (binding && BINDING_SCOPE (binding) == class_binding_level)
/* Supplement the existing binding. */
! result = cxx_binding_hide_name (IDENTIFIER_BINDING (id), decl);
else
/* Create a new binding. */
push_binding (id, decl, class_binding_level);
*************** set_identifier_type_value_with_scope (tr
*** 2336,2342 ****
if (decl)
{
if (BINDING_VALUE (binding))
! add_binding (binding, decl);
else
BINDING_VALUE (binding) = decl;
}
--- 2260,2266 ----
if (decl)
{
if (BINDING_VALUE (binding))
! cxx_binding_hide_name (binding, decl);
else
BINDING_VALUE (binding) = decl;
}
Index: name-lookup.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/name-lookup.c,v
retrieving revision 1.9
diff -p -r1.9 name-lookup.c
*** name-lookup.c 20 Aug 2003 07:06:42 -0000 1.9
--- name-lookup.c 29 Aug 2003 21:43:05 -0000
*************** cxx_binding_free (cxx_binding *binding)
*** 298,303 ****
--- 298,385 ----
binding->previous = free_bindings;
free_bindings = binding;
}
+
+ /* BINDING records an existing declaration for a namein the current scope.
+ But, DECL is another declaration for that same identifier in the
+ same scope. This is the `struct stat' hack whereby a non-typedef
+ class name or enum-name can be bound at the same level as some other
+ kind of entity.
+ 3.3.7/1
+
+ A class name (9.1) or enumeration name (7.2) can be hidden by the
+ name of an object, function, or enumerator declared in the same scope.
+ If a class or enumeration name and an object, function, or enumerator
+ are declared in the same scope (in any order) with the same name, the
+ class or enumeration name is hidden wherever the object, function, or
+ enumerator name is visible.
+
+ It's the responsibility of the caller to check that
+ inserting this name is valid here. Returns nonzero if the new binding
+ was successful. */
+
+ bool
+ cxx_binding_hide_name (cxx_binding *binding, tree decl)
+ {
+ tree bval = binding->value;
+ bool ok = true;
+
+ timevar_push (TV_NAME_LOOKUP);
+ if (TREE_CODE (decl) == TYPE_DECL && DECL_ARTIFICIAL (decl))
+ /* The new name is the type name. */
+ binding->type = decl;
+ else if (!bval)
+ /* This situation arises when push_class_level_binding moves an
+ inherited type-binding out of the way to make room for a new
+ value binding. */
+ binding->value = decl;
+ else if (TREE_CODE (bval) == TYPE_DECL && DECL_ARTIFICIAL (bval))
+ {
+ /* The old binding was a type name. It was placed in
+ BINDING_VALUE because it was thought, at the point it was
+ declared, to be the only entity with such a name. Move the
+ type name into the type slot; it is now hidden by the new
+ binding. */
+ binding->type = bval;
+ binding->value = decl;
+ binding->value_is_inherited = false;
+ }
+ else if (TREE_CODE (bval) == TYPE_DECL
+ && TREE_CODE (decl) == TYPE_DECL
+ && DECL_NAME (decl) == DECL_NAME (bval)
+ && (same_type_p (TREE_TYPE (decl), TREE_TYPE (bval))
+ /* If either type involves template parameters, we must
+ wait until instantiation. */
+ || uses_template_parms (TREE_TYPE (decl))
+ || uses_template_parms (TREE_TYPE (bval))))
+ /* We have two typedef-names, both naming the same type to have
+ the same name. This is OK because of:
+
+ [dcl.typedef]
+
+ In a given scope, a typedef specifier can be used to redefine
+ the name of any type declared in that scope to refer to the
+ type to which it already refers. */
+ ok = false;
+ /* There can be two block-scope declarations of the same variable,
+ so long as they are `extern' declarations. However, there cannot
+ be two declarations of the same static data member:
+
+ [class.mem]
+
+ A member shall not be declared twice in the
+ member-specification. */
+ else if (TREE_CODE (decl) == VAR_DECL && TREE_CODE (bval) == VAR_DECL
+ && DECL_EXTERNAL (decl) && DECL_EXTERNAL (bval)
+ && !DECL_CLASS_SCOPE_P (decl))
+ {
+ duplicate_decls (decl, binding->value);
+ ok = false;
+ }
+ else
+ ok = false;
+
+ POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, ok);
+ }
/* Return (from the stack of) the BINDING, if any, establihsed at SCOPE. */
*************** set_namespace_binding (tree name, tree s
*** 382,388 ****
|| val == error_mark_node)
BINDING_VALUE (b) = val;
else
! add_binding (b, val);
timevar_pop (TV_NAME_LOOKUP);
}
--- 464,470 ----
|| val == error_mark_node)
BINDING_VALUE (b) = val;
else
! cxx_binding_hide_name (b, val);
timevar_pop (TV_NAME_LOOKUP);
}
Index: name-lookup.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/name-lookup.h,v
retrieving revision 1.4
diff -p -r1.4 name-lookup.h
*** name-lookup.h 29 May 2003 11:04:10 -0000 1.4
--- name-lookup.h 29 Aug 2003 21:43:05 -0000
*************** struct cxx_binding GTY(())
*** 107,112 ****
--- 107,113 ----
extern cxx_binding *cxx_binding_make (tree, tree);
extern void cxx_binding_free (cxx_binding *);
+ extern bool cxx_binding_hide_name (cxx_binding *, tree);
/* True if SCOPE designates the global scope binding contour. */
#define global_scope_p(SCOPE) \