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[C++ PATCH] Using decls

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https://gcc.gnu.org/ml/gcc-patches/2019-05/msg01396.html
	gcc/cp/
	* name-lookup.h (struct cp_binding_level): Drop usings field.
	(finish_namespace_using_decl, finish_local_using_decl): Replace with ...
	(finish_nonmember_using_decl): ... this.
	* name-lookup.c (push_using_decl_1, push_using_decl):
	(do_nonmember_using_decl): ... here.  Add INSERT_P arg.  Reimplement.
	(validate_nonmember_using_decl, finish_namespace_using_decl)
	(finish_local_using_decl): Replace with ...
	(finish_nonmember_using_decl): ... this.  Drop DECL parm.
	* parser.c (cp_parser_using_declaration): Don't do lookup here.
	* pt.c (tsubst_expr): Do not do using decl lookup here.

	gcc/testsuite/
	* g++.dg/lookup/using53.C: Adjust diagnostic.

	libcc1/
	* libcp1plugin.cc (plugin_add_using_decl): Use
	finish_nonmember_using_decl.

From-SVN: r271467
This commit is contained in:
Nathan Sidwell 2019-05-21 14:33:24 +00:00 committed by Nathan Sidwell
parent f445f0f06c
commit 692af872fa
9 changed files with 196 additions and 262 deletions
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13
gcc/cp/ChangeLog
View File

@ -1,3 +1,16 @@
2019-05-21 Nathan Sidwell <nathan@acm.org>
* name-lookup.h (struct cp_binding_level): Drop usings field.
(finish_namespace_using_decl, finish_local_using_decl): Replace with ...
(finish_nonmember_using_decl): ... this.
* name-lookup.c (push_using_decl_1, push_using_decl):
(do_nonmember_using_decl): ... here. Add INSERT_P arg. Reimplement.
(validate_nonmember_using_decl, finish_namespace_using_decl)
(finish_local_using_decl): Replace with ...
(finish_nonmember_using_decl): ... this. Drop DECL parm.
* parser.c (cp_parser_using_declaration): Don't do lookup here.
* pt.c (tsubst_expr): Do not do using decl lookup here.
2019-05-21 Eric Botcazou <ebotcazou@adacore.com>
* decl2.c (cpp_check) <IS_ASSIGNMENT_OPERATOR>: New case.

397
gcc/cp/name-lookup.c
View File

@ -3829,42 +3829,6 @@ make_lambda_name (void)
return get_identifier (buf);
}
/* Insert another USING_DECL into the current binding level, returning
this declaration. If this is a redeclaration, do nothing, and
return NULL_TREE if this not in namespace scope (in namespace
scope, a using decl might extend any previous bindings). */
static tree
push_using_decl_1 (tree scope, tree name)
{
tree decl;
gcc_assert (TREE_CODE (scope) == NAMESPACE_DECL);
gcc_assert (identifier_p (name));
for (decl = current_binding_level->usings; decl; decl = DECL_CHAIN (decl))
if (USING_DECL_SCOPE (decl) == scope && DECL_NAME (decl) == name)
break;
if (decl)
return namespace_bindings_p () ? decl : NULL_TREE;
decl = build_lang_decl (USING_DECL, name, NULL_TREE);
USING_DECL_SCOPE (decl) = scope;
DECL_CHAIN (decl) = current_binding_level->usings;
current_binding_level->usings = decl;
return decl;
}
/* Wrapper for push_using_decl_1. */
static tree
push_using_decl (tree scope, tree name)
{
tree ret;
timevar_start (TV_NAME_LOOKUP);
ret = push_using_decl_1 (scope, name);
timevar_stop (TV_NAME_LOOKUP);
return ret;
}
/* Same as pushdecl, but define X in binding-level LEVEL. We rely on the
caller to set DECL_CONTEXT properly.
@ -3918,91 +3882,19 @@ pushdecl_outermost_localscope (tree x)
return ret;
}
/* Check a non-member using-declaration. Return the name and scope
being used, and the USING_DECL, or NULL_TREE on failure. */
static tree
validate_nonmember_using_decl (tree decl, tree scope, tree name)
{
/* [namespace.udecl]
A using-declaration for a class member shall be a
member-declaration. */
if (TYPE_P (scope))
{
error ("%qT is not a namespace or unscoped enum", scope);
return NULL_TREE;
}
else if (scope == error_mark_node)
return NULL_TREE;
if (TREE_CODE (decl) == TEMPLATE_ID_EXPR)
{
/* 7.3.3/5
A using-declaration shall not name a template-id. */
error ("a using-declaration cannot specify a template-id. "
"Try %<using %D%>", name);
return NULL_TREE;
}
if (TREE_CODE (decl) == NAMESPACE_DECL)
{
error ("namespace %qD not allowed in using-declaration", decl);
return NULL_TREE;
}
if (TREE_CODE (decl) == SCOPE_REF)
{
/* It's a nested name with template parameter dependent scope.
This can only be using-declaration for class member. */
error ("%qT is not a namespace", TREE_OPERAND (decl, 0));
return NULL_TREE;
}
decl = OVL_FIRST (decl);
/* Make a USING_DECL. */
tree using_decl = push_using_decl (scope, name);
if (using_decl == NULL_TREE
&& at_function_scope_p ()
&& VAR_P (decl))
/* C++11 7.3.3/10. */
error ("%qD is already declared in this scope", name);
return using_decl;
}
/* Process a local-scope or namespace-scope using declaration. SCOPE
/* Process a local-scope or namespace-scope using declaration.
FIXME
is the nominated scope to search for NAME. VALUE_P and TYPE_P
point to the binding for NAME in the current scope and are
updated. */
static void
do_nonmember_using_decl (tree scope, tree name, tree *value_p, tree *type_p)
static bool
do_nonmember_using_decl (name_lookup &lookup, bool fn_scope_p,
bool insert_p, tree *value_p, tree *type_p)
{
name_lookup lookup (name, 0);
if (!qualified_namespace_lookup (scope, &lookup))
{
error ("%qD not declared", name);
return;
}
else if (TREE_CODE (lookup.value) == TREE_LIST)
{
error ("reference to %qD is ambiguous", name);
print_candidates (lookup.value);
lookup.value = NULL_TREE;
}
if (lookup.type && TREE_CODE (lookup.type) == TREE_LIST)
{
error ("reference to %qD is ambiguous", name);
print_candidates (lookup.type);
lookup.type = NULL_TREE;
}
tree value = *value_p;
tree type = *type_p;
bool failed = false;
/* Shift the old and new bindings around so we're comparing class and
enumeration names to each other. */
@ -4018,79 +3910,95 @@ do_nonmember_using_decl (tree scope, tree name, tree *value_p, tree *type_p)
lookup.value = NULL_TREE;
}
if (lookup.value && lookup.value != value)
if (!lookup.value)
/* Nothing. */;
else if (OVL_P (lookup.value) && (!value || OVL_P (value)))
{
/* Check for using functions. */
if (OVL_P (lookup.value) && (!value || OVL_P (value)))
for (lkp_iterator usings (lookup.value); usings; ++usings)
{
for (lkp_iterator usings (lookup.value); usings; ++usings)
tree new_fn = *usings;
/* [namespace.udecl]
If a function declaration in namespace scope or block
scope has the same name and the same parameter types as a
function introduced by a using declaration the program is
ill-formed. */
bool found = false;
for (ovl_iterator old (value); !found && old; ++old)
{
tree new_fn = *usings;
tree old_fn = *old;
/* [namespace.udecl]
If a function declaration in namespace scope or block
scope has the same name and the same parameter types as a
function introduced by a using declaration the program is
ill-formed. */
bool found = false;
for (ovl_iterator old (value); !found && old; ++old)
if (new_fn == old_fn)
{
tree old_fn = *old;
if (new_fn == old_fn)
/* The function already exists in the current
namespace. */
found = true;
else if (old.using_p ())
continue; /* This is a using decl. */
else if (old.hidden_p () && !DECL_HIDDEN_FRIEND_P (old_fn))
continue; /* This is an anticipated builtin. */
else if (!matching_fn_p (new_fn, old_fn))
continue; /* Parameters do not match. */
else if (decls_match (new_fn, old_fn))
found = true;
else
{
diagnose_name_conflict (new_fn, old_fn);
found = true;
}
/* The function already exists in the current
namespace. */
found = true;
break;
}
else if (old.using_p ())
continue; /* This is a using decl. */
else if (old.hidden_p () && !DECL_HIDDEN_FRIEND_P (old_fn))
continue; /* This is an anticipated builtin. */
else if (!matching_fn_p (new_fn, old_fn))
continue; /* Parameters do not match. */
else if (decls_match (new_fn, old_fn))
{
/* Extern "C" in different namespaces. */
found = true;
break;
}
else
{
diagnose_name_conflict (new_fn, old_fn);
failed = true;
found = true;
break;
}
if (!found)
/* Unlike the overload case we don't drop anticipated
builtins here. They don't cause a problem, and
we'd like to match them with a future
declaration. */
value = ovl_insert (new_fn, value, true);
}
if (!found && insert_p)
/* Unlike the decl-pushing case we don't drop anticipated
builtins here. They don't cause a problem, and we'd
like to match them with a future declaration. */
value = ovl_insert (new_fn, value, true);
}
else if (value
/* Ignore anticipated builtins. */
&& !anticipated_builtin_p (value)
&& !decls_match (lookup.value, value))
diagnose_name_conflict (lookup.value, value);
else
value = lookup.value;
}
else if (value
/* Ignore anticipated builtins. */
&& !anticipated_builtin_p (value)
&& (fn_scope_p || !decls_match (lookup.value, value)))
{
diagnose_name_conflict (lookup.value, value);
failed = true;
}
else if (insert_p)
value = lookup.value;
if (lookup.type && lookup.type != type)
{
if (type && !decls_match (lookup.type, type))
diagnose_name_conflict (lookup.type, type);
else
{
diagnose_name_conflict (lookup.type, type);
failed = true;
}
else if (insert_p)
type = lookup.type;
}
/* If bind->value is empty, shift any class or enumeration name back. */
if (!value)
if (insert_p)
{
value = type;
type = NULL_TREE;
/* If value is empty, shift any class or enumeration name back. */
if (!value)
{
value = type;
type = NULL_TREE;
}
*value_p = value;
*type_p = type;
}
*value_p = value;
*type_p = type;
return failed;
}
/* Returns true if ANCESTOR encloses DESCENDANT, including matching.
@ -5120,84 +5028,115 @@ pushdecl_namespace_level (tree x, bool is_friend)
return t;
}
/* Process a using-declaration appearing in namespace scope. */
/* Process a using declaration in non-class scope. */
void
finish_namespace_using_decl (tree decl, tree scope, tree name)
finish_nonmember_using_decl (tree scope, tree name)
{
tree orig_decl = decl;
gcc_checking_assert (current_binding_level->kind != sk_class);
gcc_checking_assert (identifier_p (name));
gcc_checking_assert (current_binding_level->kind == sk_namespace
&& !processing_template_decl);
decl = validate_nonmember_using_decl (decl, scope, name);
if (decl == NULL_TREE)
return;
name_lookup lookup (name, 0);
tree *slot = find_namespace_slot (current_namespace, name, true);
tree val = slot ? MAYBE_STAT_DECL (*slot) : NULL_TREE;
tree type = slot ? MAYBE_STAT_TYPE (*slot) : NULL_TREE;
do_nonmember_using_decl (scope, name, &val, &type);
if (STAT_HACK_P (*slot))
if (TREE_CODE (scope) != NAMESPACE_DECL)
{
STAT_DECL (*slot) = val;
STAT_TYPE (*slot) = type;
error ("%qE is not a namespace or unscoped enum", scope);
return;
}
else if (type)
*slot = stat_hack (val, type);
else
*slot = val;
/* Emit debug info. */
cp_emit_debug_info_for_using (orig_decl, current_namespace);
}
qualified_namespace_lookup (scope, &lookup);
/* Process a using-declaration at function scope. */
void
finish_local_using_decl (tree decl, tree scope, tree name)
{
tree orig_decl = decl;
gcc_checking_assert (current_binding_level->kind != sk_class
&& current_binding_level->kind != sk_namespace);
decl = validate_nonmember_using_decl (decl, scope, name);
if (decl == NULL_TREE)
return;
add_decl_expr (decl);
cxx_binding *binding = find_local_binding (current_binding_level, name);
tree value = binding ? binding->value : NULL_TREE;
tree type = binding ? binding->type : NULL_TREE;
do_nonmember_using_decl (scope, name, &value, &type);
if (!value)
;
else if (binding && value == binding->value)
;
else if (binding && binding->value && TREE_CODE (value) == OVERLOAD)
if (!lookup.value)
{
update_local_overload (IDENTIFIER_BINDING (name), value);
IDENTIFIER_BINDING (name)->value = value;
error ("%qD has not been declared in %qE", name, scope);
return;
}
else
/* Install the new binding. */
push_local_binding (name, value, true);
if (!type)
;
else if (binding && type == binding->type)
;
else
if (TREE_CODE (lookup.value) == TREE_LIST
/* But we can (independently) have ambiguous implicit typedefs. */
|| (lookup.type && TREE_CODE (lookup.type) == TREE_LIST))
{
push_local_binding (name, type, true);
set_identifier_type_value (name, type);
error ("reference to %qD is ambiguous", name);
print_candidates (TREE_CODE (lookup.value) == TREE_LIST
? lookup.value : lookup.type);
return;
}
if (TREE_CODE (lookup.value) == NAMESPACE_DECL)
{
error ("using-declaration may not name namespace %qD", lookup.value);
return;
}
/* Emit debug info. */
if (!processing_template_decl)
cp_emit_debug_info_for_using (orig_decl, current_scope ());
cp_emit_debug_info_for_using (lookup.value,
current_binding_level->this_entity);
if (current_binding_level->kind == sk_namespace)
{
tree *slot = find_namespace_slot (current_namespace, name, true);
tree value = MAYBE_STAT_DECL (*slot);
tree type = MAYBE_STAT_TYPE (*slot);
do_nonmember_using_decl (lookup, false, true, &value, &type);
if (STAT_HACK_P (*slot))
{
STAT_DECL (*slot) = value;
STAT_TYPE (*slot) = type;
}
else if (type)
*slot = stat_hack (value, type);
else
*slot = value;
}
else
{
tree using_decl = build_lang_decl (USING_DECL, name, NULL_TREE);
USING_DECL_SCOPE (using_decl) = scope;
add_decl_expr (using_decl);
cxx_binding *binding = find_local_binding (current_binding_level, name);
tree value = NULL;
tree type = NULL;
if (binding)
{
value = binding->value;
type = binding->type;
}
/* DR 36 questions why using-decls at function scope may not be
duplicates. Disallow it, as C++11 claimed and PR 20420
implemented. */
do_nonmember_using_decl (lookup, true, true, &value, &type);
if (!value)
;
else if (binding && value == binding->value)
;
else if (binding && binding->value && TREE_CODE (value) == OVERLOAD)
{
update_local_overload (IDENTIFIER_BINDING (name), value);
IDENTIFIER_BINDING (name)->value = value;
}
else
/* Install the new binding. */
// FIXME: Short circuit P_L_B
push_local_binding (name, value, true);
if (!type)
;
else if (binding && type == binding->type)
;
else
{
push_local_binding (name, type, true);
set_identifier_type_value (name, type);
}
}
}
/* Return the declarations that are members of the namespace NS. */

8
gcc/cp/name-lookup.h
View File

@ -176,9 +176,6 @@ struct GTY(()) cp_binding_level {
are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD. */
tree names;
/* A list of USING_DECL nodes. */
tree usings;
/* Using directives. */
vec<tree, va_gc> *using_directives;
@ -315,9 +312,8 @@ extern tree innermost_non_namespace_value (tree);
extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
extern void cp_emit_debug_info_for_using (tree, tree);
extern void finish_namespace_using_decl (tree, tree, tree);
extern void finish_local_using_decl (tree, tree, tree);
extern void finish_using_directive (tree, tree);
extern void finish_nonmember_using_decl (tree scope, tree name);
extern void finish_using_directive (tree target, tree attribs);
extern tree pushdecl (tree, bool is_friend = false);
extern tree pushdecl_outermost_localscope (tree);
extern tree pushdecl_top_level (tree, bool is_friend = false);

19
gcc/cp/parser.c
View File

@ -19519,24 +19519,7 @@ cp_parser_using_declaration (cp_parser* parser,
finish_member_declaration (decl);
}
else
{
decl = cp_parser_lookup_name_simple (parser,
identifier,
token->location);
if (decl == error_mark_node)
cp_parser_name_lookup_error (parser, identifier,
decl, NLE_NULL,
token->location);
else if (check_for_bare_parameter_packs (decl))
{
cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON);
return false;
}
else if (!at_namespace_scope_p ())
finish_local_using_decl (decl, qscope, identifier);
else
finish_namespace_using_decl (decl, qscope, identifier);
}
finish_nonmember_using_decl (qscope, identifier);
}
if (!access_declaration_p

8
gcc/cp/pt.c
View File

@ -17072,13 +17072,7 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
tree name = DECL_NAME (decl);
scope = tsubst (scope, args, complain, in_decl);
decl = lookup_qualified_name (scope, name,
/*is_type_p=*/false,
/*complain=*/false);
if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
qualified_name_lookup_error (scope, name, decl, input_location);
else
finish_local_using_decl (decl, scope, name);
finish_nonmember_using_decl (scope, name);
}
else if (is_capture_proxy (decl)
&& !DECL_TEMPLATE_INSTANTIATION (current_function_decl))

4
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,7 @@
2019-05-21 Nathan Sidwell <nathan@acm.org>
* g++.dg/lookup/using53.C: Adjust diagnostic.
2019-05-21 Richard Biener <rguenther@suse.de>
PR middle-end/90510

2
gcc/testsuite/g++.dg/lookup/using53.C
View File

@ -49,5 +49,5 @@ void
f ()
{
using N::i;
using N::i; // { dg-error "declared" }
using N::i; // { dg-error "redeclaration" }
}

5
libcc1/ChangeLog
View File

@ -1,3 +1,8 @@
2019-05-21 Nathan Sidwell <nathan@acm.org>
* libcp1plugin.cc (plugin_add_using_decl): Use
finish_nonmember_using_decl.
2019-05-20 Nathan Sidwell <nathan@acm.org>
* libcp1plugin.cc (plugin_add_using_namespace): Call renamed

2
libcc1/libcp1plugin.cc
View File

@ -1019,7 +1019,7 @@ plugin_add_using_decl (cc1_plugin::connection *,
{
/* We can't be at local scope. */
gcc_assert (at_namespace_scope_p ());
finish_namespace_using_decl (target, tcontext, identifier);
finish_nonmember_using_decl (tcontext, identifier);
}
return 1;