For C2<T> to be considered the "current instantiation", we need to call
xref_basetypes while we're still pushed into its scope. So we can
actually simplify the code by moving the call into cp_parser_class_head.
Once we've fixed that, we need to fix tsubst_decl to handle USING_DECLs
for members of the current instantiation, since the scope can be a
dependent type even though we can do name lookup in it.
The discussion of the PR also pointed out that EDG rejects code like
template <class T> struct A
{
struct B : A { };
};
because A<T> is not complete yet. This makes sense to me, so I've added
this diagnostic as a pedwarn (so code that uses this pattern will
continue to compile for now).
Tested x86_64-pc-linux-gnu, applying the first patch to trunk and 4.7,
the second to trunk only.
commit 5d594c4a4616821068b111489b26a88183d6eb22
Author: Jason Merrill <ja...@redhat.com>
Date: Tue Jul 17 00:45:54 2012 -0400
PR c++/53549
* parser.c (cp_parser_class_head): Call xref_basetypes here.
(cp_parser_class_specifier_1): Not here.
* pt.c (tsubst_decl) [USING_DECL]: Check uses_template_parms
as well as DECL_DEPENDENT_P.
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 1428a26..df23299 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -2008,7 +2008,7 @@ static tree cp_parser_class_name
static tree cp_parser_class_specifier
(cp_parser *);
static tree cp_parser_class_head
- (cp_parser *, bool *, tree *);
+ (cp_parser *, bool *);
static enum tag_types cp_parser_class_key
(cp_parser *);
static void cp_parser_member_specification_opt
@@ -17961,15 +17961,13 @@ cp_parser_class_specifier_1 (cp_parser* parser)
bool saved_in_unbraced_linkage_specification_p;
tree old_scope = NULL_TREE;
tree scope = NULL_TREE;
- tree bases;
cp_token *closing_brace;
push_deferring_access_checks (dk_no_deferred);
/* Parse the class-head. */
type = cp_parser_class_head (parser,
- &nested_name_specifier_p,
- &bases);
+ &nested_name_specifier_p);
/* If the class-head was a semantic disaster, skip the entire body
of the class. */
if (!type)
@@ -17986,18 +17984,6 @@ cp_parser_class_specifier_1 (cp_parser* parser)
return error_mark_node;
}
- /* Process the base classes. If they're invalid, skip the
- entire class body. */
- if (!xref_basetypes (type, bases))
- {
- /* Consuming the closing brace yields better error messages
- later on. */
- if (cp_parser_skip_to_closing_brace (parser))
- cp_lexer_consume_token (parser->lexer);
- pop_deferring_access_checks ();
- return error_mark_node;
- }
-
/* Issue an error message if type-definitions are forbidden here. */
cp_parser_check_type_definition (parser);
/* Remember that we are defining one more class. */
@@ -18283,14 +18269,14 @@ cp_parser_class_specifier (cp_parser* parser)
static tree
cp_parser_class_head (cp_parser* parser,
- bool* nested_name_specifier_p,
- tree *bases)
+ bool* nested_name_specifier_p)
{
tree nested_name_specifier;
enum tag_types class_key;
tree id = NULL_TREE;
tree type = NULL_TREE;
tree attributes;
+ tree bases;
cp_virt_specifiers virt_specifiers = VIRT_SPEC_UNSPECIFIED;
bool template_id_p = false;
bool qualified_p = false;
@@ -18307,8 +18293,6 @@ cp_parser_class_head (cp_parser* parser,
num_templates = 0;
parser->colon_corrects_to_scope_p = false;
- *bases = NULL_TREE;
-
/* Look for the class-key. */
class_key = cp_parser_class_key (parser);
if (class_key == none_type)
@@ -18671,7 +18655,15 @@ cp_parser_class_head (cp_parser* parser,
/* Get the list of base-classes, if there is one. */
if (cp_lexer_next_token_is (parser->lexer, CPP_COLON))
- *bases = cp_parser_base_clause (parser);
+ bases = cp_parser_base_clause (parser);
+ else
+ bases = NULL_TREE;
+
+ /* If we're really defining a class, process the base classes.
+ If they're invalid, fail. */
+ if (type && cp_lexer_next_token_is (parser->lexer, CPP_OPEN_BRACE)
+ && !xref_basetypes (type, bases))
+ type = NULL_TREE;
done:
/* Leave the scope given by the nested-name-specifier. We will
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 95c6464..542f57a 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -10235,8 +10235,12 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
break;
case USING_DECL:
- /* We reach here only for member using decls. */
- if (DECL_DEPENDENT_P (t))
+ /* We reach here only for member using decls. We also need to check
+ uses_template_parms because DECL_DEPENDENT_P is not set for a
+ using-declaration that designates a member of the current
+ instantiation (c++/53549). */
+ if (DECL_DEPENDENT_P (t)
+ || uses_template_parms (USING_DECL_SCOPE (t)))
{
r = do_class_using_decl
(tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
diff --git a/gcc/testsuite/g++.dg/parse/crash35.C b/gcc/testsuite/g++.dg/parse/crash35.C
index 4937cdc..161edad 100644
--- a/gcc/testsuite/g++.dg/parse/crash35.C
+++ b/gcc/testsuite/g++.dg/parse/crash35.C
@@ -3,5 +3,5 @@
struct a {};
-class foo : public a, a
-{ /* { dg-error "duplicate base type|at end of input" } */
+class foo : public a, a // { dg-error "duplicate base" }
+{ /* { dg-error "at end of input" } */
diff --git a/gcc/testsuite/g++.dg/template/current-inst1.C b/gcc/testsuite/g++.dg/template/current-inst1.C
new file mode 100644
index 0000000..8f42ef8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/current-inst1.C
@@ -0,0 +1,19 @@
+// PR c++/53549
+
+template<typename T>
+struct C2
+{
+ int operator()();
+
+ template<int> struct F2;
+};
+
+
+template<typename T>
+template<int I>
+struct C2<T>::F2 : C2<T>
+{
+ using C2<T>::operator();
+};
+
+C2<int>::F2<42> f;
commit 22ef026b9bac683273c17d80170be4721241b706
Author: Jason Merrill <ja...@redhat.com>
Date: Tue Jul 17 06:15:20 2012 -0400
* decl.c (xref_basetypes): Complain about incomplete template base.
* class.c (finish_struct): Adjust variants in templates, too.
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 3877a27..82c28fa 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -6325,6 +6325,15 @@ finish_struct (tree t, tree attributes)
/* Remember current #pragma pack value. */
TYPE_PRECISION (t) = maximum_field_alignment;
+
+ /* Fix up any variants we've already built. */
+ for (x = TYPE_NEXT_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x))
+ {
+ TYPE_SIZE (x) = TYPE_SIZE (t);
+ TYPE_SIZE_UNIT (x) = TYPE_SIZE_UNIT (t);
+ TYPE_FIELDS (x) = TYPE_FIELDS (t);
+ TYPE_METHODS (x) = TYPE_METHODS (t);
+ }
}
else
finish_struct_1 (t);
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 842c2d8..84b78f6 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -11843,7 +11843,14 @@ xref_basetypes (tree ref, tree base_list)
{
tree basetype = TREE_VALUE (*basep);
- if (!(processing_template_decl && uses_template_parms (basetype))
+ /* The dependent_type_p call below should really be dependent_scope_p
+ so that we give a hard error about using an incomplete type as a
+ base, but we allow it with a pedwarn for backward
+ compatibility. */
+ if (processing_template_decl
+ && CLASS_TYPE_P (basetype) && TYPE_BEING_DEFINED (basetype))
+ cxx_incomplete_type_diagnostic (NULL_TREE, basetype, DK_PEDWARN);
+ if (!dependent_type_p (basetype)
&& !complete_type_or_else (basetype, NULL))
/* An incomplete type. Remove it from the list. */
*basep = TREE_CHAIN (*basep);
diff --git a/gcc/testsuite/g++.dg/template/inherit8.C b/gcc/testsuite/g++.dg/template/inherit8.C
index a9b2bdb..3176dc0 100644
--- a/gcc/testsuite/g++.dg/template/inherit8.C
+++ b/gcc/testsuite/g++.dg/template/inherit8.C
@@ -4,9 +4,9 @@ template <typename T>
struct A
{
template <typename U>
- struct B : public A <B<U> >
+ struct B : public A <B<U> > // { dg-error "declaration" }
{
- struct C : public B<U>
+ struct C : public B<U> // { dg-error "incomplete" }
{
};
};
diff --git a/gcc/testsuite/g++.dg/template/using21.C b/gcc/testsuite/g++.dg/template/using21.C
index 7f61f85..65313aa 100644
--- a/gcc/testsuite/g++.dg/template/using21.C
+++ b/gcc/testsuite/g++.dg/template/using21.C
@@ -4,25 +4,34 @@
template<typename T>
struct A
{
- int foo;
+ int foo;
- struct B : A<T>
- {
- using A::foo;
- };
+ struct B;
+ struct C;
+ struct D;
+ struct E;
+};
- struct C : A
- {
- using A::foo;
- };
+template <class T>
+struct A<T>::B : A<T>
+{
+ using A::foo;
+};
- struct D : A<T>
- {
- using A<T>::foo;
- };
+template <class T>
+struct A<T>::C : A
+{
+ using A::foo;
+};
+
+template <class T>
+struct A<T>::D : A<T>
+{
+ using A<T>::foo;
+};
- struct E : A
- {
- using A<T>::foo;
- };
+template <class T>
+struct A<T>::E : A
+{
+ using A<T>::foo;
};
diff --git a/gcc/testsuite/g++.dg/template/using22.C b/gcc/testsuite/g++.dg/template/using22.C
index b456e62..9ea3d8a 100644
--- a/gcc/testsuite/g++.dg/template/using22.C
+++ b/gcc/testsuite/g++.dg/template/using22.C
@@ -6,28 +6,39 @@ template <class T> struct Z {};
template<typename T>
struct A
{
- struct B : A<T>
- {
- using A::nonexist; // { dg-error "no members matching" }
- };
+ struct B;
+ struct C;
+ struct D;
+ struct E;
+ struct F;
+};
+
+template <class T>
+struct A<T>::B : A<T>
+{
+ using A::nonexist; // { dg-error "no members matching" }
+};
- struct C : A
- {
- using A::nonexist; // { dg-error "no members matching" }
- };
+template <class T>
+struct A<T>::C : A
+{
+ using A::nonexist; // { dg-error "no members matching" }
+};
- struct D : A<T>
- {
- using A<T>::nonexist; // { dg-error "no members matching" }
- };
+template <class T>
+struct A<T>::D : A<T>
+{
+ using A<T>::nonexist; // { dg-error "no members matching" }
+};
- struct E : A
- {
- using A<T>::nonexist; // { dg-error "no members matching" }
- };
+template <class T>
+struct A<T>::E : A
+{
+ using A<T>::nonexist; // { dg-error "no members matching" }
+};
- struct F : Z<T>
- {
- using Z<T>::nonexist;
- };
+template <class T>
+struct A<T>::F : Z<T>
+{
+ using Z<T>::nonexist;
};
