We were complaining about IsType<T> not being constant, but we shouldn't
think about it having a constant value or not, because it is
type-dependent; a variable template can have a specialization with a
different type.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit dff5042c89e83955238c9ec5b43a73fa2d2f3310
Author: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue Jan 6 20:44:51 2015 +0000
PR c++/64455
* pt.c (type_dependent_expression_p): Handle variable templates.
* constexpr.c (potential_constant_expression_1): Use it.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@219268 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index ee796df..4da263e 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -3882,7 +3882,7 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict,
|| !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t))
|| !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))
&& !var_in_constexpr_fn (t)
- && !dependent_type_p (TREE_TYPE (t)))
+ && !type_dependent_expression_p (t))
{
if (flags & tf_error)
non_const_var_error (t);
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 15645b9..de2f6a4 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -21369,6 +21369,14 @@ type_dependent_expression_p (tree expression)
&& DECL_INITIAL (expression))
return true;
+ /* A variable template specialization is type-dependent if it has any
+ dependent template arguments. */
+ if (VAR_P (expression)
+ && DECL_LANG_SPECIFIC (expression)
+ && DECL_TEMPLATE_INFO (expression)
+ && variable_template_p (DECL_TI_TEMPLATE (expression)))
+ return any_dependent_template_arguments_p (DECL_TI_ARGS (expression));
+
if (TREE_TYPE (expression) == unknown_type_node)
{
if (TREE_CODE (expression) == ADDR_EXPR)
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ21.C b/gcc/testsuite/g++.dg/cpp1y/var-templ21.C
new file mode 100644
index 0000000..a7b0899
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ21.C
@@ -0,0 +1,25 @@
+// PR c++/64455
+// { dg-do compile { target c++14 } }
+
+template<typename Type>
+constexpr bool IsType = true;
+
+template <bool b, class T> struct Test
+{
+};
+
+template <class T>
+struct Test<true, T>
+{
+ typedef T type;
+};
+
+template<class T>
+struct X {
+ typedef typename Test<IsType<T>,T>::type type;
+};
+
+int main()
+{
+ X<int>::type t;
+}
commit 33dba2339488931a8630a2414be1d9d4604370e8
Author: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue Jan 6 20:44:59 2015 +0000
* parser.c (cp_parser_nested_name_specifier_opt): Diagnose invalid
template-ids.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@219269 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 22dff06..5c23a36 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -5435,6 +5435,46 @@ cp_parser_nested_name_specifier_opt (cp_parser *parser,
cp_lexer_consume_token (parser->lexer);
}
+ if (cp_lexer_next_token_is (parser->lexer, CPP_TEMPLATE_ID)
+ && cp_lexer_nth_token_is (parser->lexer, 2, CPP_SCOPE))
+ {
+ /* If we have a non-type template-id followed by ::, it can't
+ possibly be valid. */
+ token = cp_lexer_peek_token (parser->lexer);
+ tree tid = token->u.tree_check_value->value;
+ if (TREE_CODE (tid) == TEMPLATE_ID_EXPR
+ && TREE_CODE (TREE_OPERAND (tid, 0)) != IDENTIFIER_NODE)
+ {
+ tree tmpl = NULL_TREE;
+ if (is_overloaded_fn (tid))
+ {
+ tree fns = get_fns (tid);
+ if (!OVL_CHAIN (fns))
+ tmpl = OVL_CURRENT (fns);
+ error_at (token->location, "function template-id %qD "
+ "in nested-name-specifier", tid);
+ }
+ else
+ {
+ /* Variable template. */
+ tmpl = TREE_OPERAND (tid, 0);
+ gcc_assert (variable_template_p (tmpl));
+ error_at (token->location, "variable template-id %qD "
+ "in nested-name-specifier", tid);
+ }
+ if (tmpl)
+ inform (DECL_SOURCE_LOCATION (tmpl),
+ "%qD declared here", tmpl);
+
+ parser->scope = error_mark_node;
+ error_p = true;
+ /* As below. */
+ success = true;
+ cp_lexer_consume_token (parser->lexer);
+ cp_lexer_consume_token (parser->lexer);
+ }
+ }
+
if (cp_parser_uncommitted_to_tentative_parse_p (parser))
break;
/* If the next token is an identifier, and the one after
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ20.C b/gcc/testsuite/g++.dg/cpp1y/var-templ20.C
new file mode 100644
index 0000000..38bd370
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ20.C
@@ -0,0 +1,12 @@
+// { dg-do compile { target c++14 } }
+
+template <bool> struct Sink {};
+template <class T> void fn();
+template <class T> T var = T();
+
+template <class T> void f()
+{
+ Sink<fn<T>::value>(); // { dg-error "function" }
+ Sink<var<T>::value>(); // { dg-error "variable" }
+}
+// { dg-prune-output "template argument" }
