c++: -Wmismatched-tags and modules

In Wmismatched-tags-6.C, we try to compare two declarations of the Cp alias
template, and ICE trying to check whether they're in module purview.  We
need to check DECL_LANG_SPECIFIC like elsewhere in the compiler.

gcc/cp/ChangeLog:

	* decl.cc (duplicate_decls): Only check PURVIEW_P if
	DECL_LANG_SPECIFIC.

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 07fb9855cd20b4fbc91fd55b4961abedb7269299..0c5b5c06a12e73e149d0a5446336d12e05687172 100644 (file)
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -2530,7 +2530,7 @@ duplicate_decls (tree newdecl, tree olddecl, bool hiding, bool was_hidden)
 
       /* Propagate purviewness and importingness as with
         set_instantiating_module.  */
-      if (modules_p ())
+      if (modules_p () && DECL_LANG_SPECIFIC (new_result))
        {
          if (DECL_MODULE_PURVIEW_P (new_result))
            DECL_MODULE_PURVIEW_P (old_result) = true;