[PR c++/90613] Fix using-decl debug bloat

https://gcc.gnu.org/ml/gcc-patches/2019-08/msg01888.html
	cp/
	PR c++/90613
	* name-lookup.c (cp_emit_debug_info): Check for builtins during
	overload iteration.

	testsuite/
	PR c++/90613
	* g++.dg/lookup/using61.C: New.

From-SVN: r274991

gcc/cp/ChangeLog

+2019-08-28  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/90613
+	* name-lookup.c (cp_emit_debug_info): Check for builtins during
+	overload iteration.
+
 2019-08-27  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/81676 - bogus -Wunused warnings in constexpr if.

gcc/cp/name-lookup.c

@@ -7455,13 +7455,6 @@ cp_emit_debug_info_for_using (tree t, tree context)
   if (seen_error ())
     return;
 
-  /* Ignore this FUNCTION_DECL if it refers to a builtin declaration
-     of a builtin function.  */
-  if (TREE_CODE (t) == FUNCTION_DECL
-      && DECL_EXTERNAL (t)
-      && fndecl_built_in_p (t))
-    return;
-
   /* Do not supply context to imported_module_or_decl, if
      it is a global namespace.  */
   if (context == global_namespace)
@@ -7469,18 +7462,26 @@ cp_emit_debug_info_for_using (tree t, tree context)
 
   t = MAYBE_BASELINK_FUNCTIONS (t);
 
-  /* FIXME: Handle TEMPLATE_DECLs.  */
   for (lkp_iterator iter (t); iter; ++iter)
     {
       tree fn = *iter;
-      if (TREE_CODE (fn) != TEMPLATE_DECL)
-	{
-	  if (building_stmt_list_p ())
-	    add_stmt (build_stmt (input_location, USING_STMT, fn));
-	  else
-	    debug_hooks->imported_module_or_decl (fn, NULL_TREE, context,
-						  false, false);
-	}
+
+      if (TREE_CODE (fn) == TEMPLATE_DECL)
+	/* FIXME: Handle TEMPLATE_DECLs.  */
+	continue;
+      
+      /* Ignore this FUNCTION_DECL if it refers to a builtin declaration
+	 of a builtin function.  */
+      if (TREE_CODE (fn) == FUNCTION_DECL
+	  && DECL_EXTERNAL (fn)
+	  && fndecl_built_in_p (fn))
+	continue;
+
+      if (building_stmt_list_p ())
+	add_stmt (build_stmt (input_location, USING_STMT, fn));
+      else
+	debug_hooks->imported_module_or_decl (fn, NULL_TREE, context,
+					      false, false);
     }
 }
 

gcc/testsuite/ChangeLog

+2019-08-16  Martin Liska  <mliska@suse.cz>
+
+	PR c++/90613
+	* g++.dg/lookup/using61.C: New.
+
 2019-08-28  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	PR middle-end/89544

gcc/testsuite/g++.dg/lookup/using61.C

+// { dg-options "-gdwarf-2" }
+/* { dg-skip-if "No Dwarf" { { *-*-aix* hppa*-*-hpux* } && { ! hppa*64*-*-* } } } */
+
+extern "C" long double nanl(const char *);
+using ::nanl;
+
+// We should elide the using for this extern C builtin
+// { dg-final { scan-assembler-not ".debug_info" } }