c++: Fix exported using decls of templates

We need to look at DECL_TEMPLATE_RESULT to get the module attachment.

	PR c++/106849

gcc/cp/ChangeLog:

	* name-lookup.cc (do_nonmember_using_decl): Handle
	TEMPLATE_DECLs when checking module attachment.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/using-9.C: New test.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Signed-off-by: Nathan Sidwell <nathan@acm.org>

diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index a8b9229b29ec9d9678101f691a41a57d8d24fde6..50aeb776ae271b68803a980b6771902ebc78d07f 100644 (file)
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -4846,12 +4846,16 @@ do_nonmember_using_decl (name_lookup &lookup, bool fn_scope_p,
          bool exporting = revealing_p && module_exporting_p ();
          if (exporting)
            {
+             /* Module flags for templates are on the template_result.  */
+             tree decl = STRIP_TEMPLATE (new_fn);
+
              /* If the using decl is exported, the things it refers
-                to must also be exported (or not habve module attachment).  */
-             if (!DECL_MODULE_EXPORT_P (new_fn)
-                 && (DECL_LANG_SPECIFIC (new_fn)
-                     && DECL_MODULE_ATTACH_P (new_fn)))
+                to must also be exported (or not have module attachment).  */
+             if (!DECL_MODULE_EXPORT_P (decl)
+                 && (DECL_LANG_SPECIFIC (decl)
+                     && DECL_MODULE_ATTACH_P (decl)))
                {
+                 auto_diagnostic_group d;
                  error ("%q#D does not have external linkage", new_fn);
                  inform (DECL_SOURCE_LOCATION (new_fn),
                          "%q#D declared here", new_fn);

diff --git a/gcc/testsuite/g++.dg/modules/using-9.C b/gcc/testsuite/g++.dg/modules/using-9.C
new file mode 100644 (file)
index 0000000..4290280
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/using-9.C
@@ -0,0 +1,13 @@
+// PR c++/106849
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi !lib }
+
+export module lib;
+
+namespace outer {
+  template<typename T> void any_of(T) { }  // { dg-note "declared here" }
+}
+
+export using outer::any_of;  // { dg-error "does not have external linkage" }
+
+// { dg-prune-output "not writing module" }