Since nobody else seemed to be working on finishing up variable template
support, I've gone ahead and done it. There were only a few tweaks needed.
For the pr59638.C issue, I'm throwing away the implicit template
parameter list before we call start_decl so we don't actually create an
implicit template. I expect that getting from there to doing type
deduction from the initializer will be pretty simple; my guess is that
it doesn't work as desired now mainly because type_uses_auto doesn't
look into parameter types.
Jason
commit 9c0cd66186ac4159b7541ea5968eda6d599d3ab8
Author: Jason Merrill <ja...@redhat.com>
Date: Fri Aug 22 16:34:08 2014 -0400
Allow non-constexpr variable templates.
* decl2.c (note_variable_template_instantiation): New.
* cp-tree.h: Declare it.
* pt.c (instantiate_decl): Call it.
(push_template_decl_real): Allow non-constexpr variable templates.
* semantics.c (finish_id_expression): Mark the variable template
instantiation as used.
* mangle.c (write_mangled_name): Variable template instantiations
are mangled.
* parser.c (cp_parser_init_declarator): Complain about
non-function implicit templates.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 81c7fd6..5d4df6b 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -5051,6 +5051,8 @@ variable_template_p (tree t)
{
if (TREE_CODE (t) != TEMPLATE_DECL)
return false;
+ if (!PRIMARY_TEMPLATE_P (t))
+ return false;
if (tree r = DECL_TEMPLATE_RESULT (t))
return VAR_P (r);
return false;
@@ -5393,6 +5395,7 @@ extern tree get_tls_wrapper_fn (tree);
extern void mark_needed (tree);
extern bool decl_needed_p (tree);
extern void note_vague_linkage_fn (tree);
+extern void note_variable_template_instantiation (tree);
extern tree build_artificial_parm (tree, tree);
extern bool possibly_inlined_p (tree);
extern int parm_index (tree);
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 63583a8..74a10fb 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -787,6 +787,14 @@ note_vague_linkage_fn (tree decl)
vec_safe_push (deferred_fns, decl);
}
+/* As above, but for variable template instantiations. */
+
+void
+note_variable_template_instantiation (tree decl)
+{
+ vec_safe_push (pending_statics, decl);
+}
+
/* We have just processed the DECL, which is a static data member.
The other parameters are as for cp_finish_decl. */
diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index 40508ab..283983f 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -667,6 +667,8 @@ write_mangled_name (const tree decl, bool top_level)
}
}
else if (VAR_P (decl)
+ /* Variable template instantiations are mangled. */
+ && !(DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl))
/* The names of non-static global variables aren't mangled. */
&& DECL_EXTERNAL_LINKAGE_P (decl)
&& (CP_DECL_CONTEXT (decl) == global_namespace
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 4dc7c33..7d8b710 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -16779,6 +16779,8 @@ cp_parser_init_declarator (cp_parser* parser,
/* Peek at the next token. */
token = cp_lexer_peek_token (parser->lexer);
+ bool bogus_implicit_tmpl = false;
+
if (function_declarator_p (declarator))
{
/* Check to see if the token indicates the start of a
@@ -16831,6 +16833,19 @@ cp_parser_init_declarator (cp_parser* parser,
return decl;
}
}
+ else if (parser->fully_implicit_function_template_p)
+ {
+ /* A non-template declaration involving a function parameter list
+ containing an implicit template parameter will be made into a
+ template. If the resulting declaration is not going to be an
+ actual function then finish the template scope here to prevent it.
+ An error message will be issued once we have a decl to talk about.
+
+ FIXME probably we should do type deduction rather than create an
+ implicit template, but the standard currently doesn't allow it. */
+ bogus_implicit_tmpl = true;
+ finish_fully_implicit_template (parser, NULL_TREE);
+ }
/* [dcl.dcl]
@@ -16996,21 +17011,10 @@ cp_parser_init_declarator (cp_parser* parser,
warning (OPT_Wattributes,
"attributes after parenthesized initializer ignored");
- /* A non-template declaration involving a function parameter list containing
- an implicit template parameter will have been made into a template. If it
- turns out that the resulting declaration is not an actual function then
- finish the template declaration here. An error message will already have
- been issued. */
- if (parser->fully_implicit_function_template_p)
- if (!function_declarator_p (declarator))
- {
- if (pushed_scope)
- {
- pop_scope (pushed_scope);
- pushed_scope = 0;
- }
- finish_fully_implicit_template (parser, /*member_decl_opt=*/0);
- }
+ /* And now complain about a non-function implicit template. */
+ if (bogus_implicit_tmpl)
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "non-function %qD declared as implicit template", decl);
/* For an in-class declaration, use `grokfield' to create the
declaration. */
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 41fd424..14b5bfb 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -4777,14 +4777,7 @@ push_template_decl_real (tree decl, bool is_friend)
/* alias-declaration */
gcc_assert (!DECL_ARTIFICIAL (decl));
else if (VAR_P (decl))
- {
- if (!DECL_DECLARED_CONSTEXPR_P (decl))
- {
- sorry ("template declaration of non-constexpr variable %qD",
- decl);
- return error_mark_node;
- }
- }
+ /* C++14 variable template. */;
else
{
error ("template declaration of %q#D", decl);
@@ -20106,6 +20099,9 @@ instantiate_decl (tree d, int defer_ok,
if (enter_context)
pop_nested_class ();
+
+ if (variable_template_p (td))
+ note_variable_template_instantiation (d);
}
else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
synthesize_method (d);
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 531927e..aed820c 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -3512,6 +3512,7 @@ finish_id_expression (tree id_expression,
&& variable_template_p (TREE_OPERAND (decl, 0)))
{
decl = finish_template_variable (decl);
+ mark_used (decl);
}
else if (scope)
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/pr59638.C b/gcc/testsuite/g++.dg/cpp1y/pr59638.C
index a4c63ac..ce90483 100644
--- a/gcc/testsuite/g++.dg/cpp1y/pr59638.C
+++ b/gcc/testsuite/g++.dg/cpp1y/pr59638.C
@@ -1,13 +1,12 @@
// PR c++/59638
// { dg-do compile { target c++1y } }
// { dg-options "" }
-// { dg-excess-errors "sorry" }
-void (*a)(auto); // { dg-error "" "" { xfail *-*-* } }
+void (*a)(auto); // { dg-error "" }
-void (*b)(auto) = 0; // { dg-error "" "" { xfail *-*-* } }
+void (*b)(auto) = 0; // { dg-error "" }
-typedef void (*f)(auto); // { dg-error "template declaration" }
+typedef void (*f)(auto); // { dg-error "" }
struct A
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/pr60626.C b/gcc/testsuite/g++.dg/cpp1y/pr60626.C
index 39ea438..314d6da 100644
--- a/gcc/testsuite/g++.dg/cpp1y/pr60626.C
+++ b/gcc/testsuite/g++.dg/cpp1y/pr60626.C
@@ -4,4 +4,4 @@
struct A {};
-void (*A::p)(auto) = 0; // { dg-error "static member|non-template" }
+void (*A::p)(auto) = 0; // { dg-error "static member|template" }
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ7.C b/gcc/testsuite/g++.dg/cpp1y/var-templ7.C
new file mode 100644
index 0000000..1e59cf4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ7.C
@@ -0,0 +1,8 @@
+// { dg-do compile { target c++1y } }
+
+template <class T> T var = 0;
+
+int main()
+{
+ var<int> = 42;
+}
diff --git a/gcc/testsuite/g++.old-deja/g++.pt/var1.C b/gcc/testsuite/g++.old-deja/g++.pt/var1.C
index ec91bc4..08d65e9 100644
--- a/gcc/testsuite/g++.old-deja/g++.pt/var1.C
+++ b/gcc/testsuite/g++.old-deja/g++.pt/var1.C
@@ -1,5 +1,4 @@
// { dg-do assemble }
// Origin: Jason Merrill <ja...@cygnus.com>
-// { dg-excess-errors "sorry" }
-template <class T> T t; // template declaration of t
+template <class T> T t; // { dg-error "" "" { target { ! c++1y } } } template declaration of t
