1 files changed, 11 insertions, 43 deletions

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 4ed424f..d36564d 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -717,24 +717,12 @@ inherited_ctor_rejection (void)
   return r;
 }
 
-// Build a constraint failure record, saving information into the
-// template_instantiation field of the rejection. If FN is not a template
-// declaration, the TMPL member is the FN declaration and TARGS is empty.
+/* Build a constraint failure record.  */
 
 static struct rejection_reason *
-constraint_failure (tree fn)
+constraint_failure (void)
 {
   struct rejection_reason *r = alloc_rejection (rr_constraint_failure);
-  if (tree ti = DECL_TEMPLATE_INFO (fn))
-    {
-      r->u.template_instantiation.tmpl = TI_TEMPLATE (ti);
-      r->u.template_instantiation.targs = TI_ARGS (ti);
-    }
-  else
-    {
-      r->u.template_instantiation.tmpl = fn;
-      r->u.template_instantiation.targs = NULL_TREE;
-    }
   return r;
 }
 
@@ -2251,10 +2239,9 @@ add_function_candidate (struct z_candidate **candidates,
 
   /* Second, for a function to be viable, its constraints must be
      satisfied. */
-  if (flag_concepts && viable
-      && !constraints_satisfied_p (fn))
+  if (flag_concepts && viable && !constraints_satisfied_p (fn))
     {
-      reason = constraint_failure (fn);
+      reason = constraint_failure ();
       viable = false;
     }
 
@@ -3729,11 +3716,7 @@ print_z_candidate (location_t loc, const char *msgstr,
 		  "class type is invalid");
 	  break;
 	case rr_constraint_failure:
-	  {
-	    tree tmpl = r->u.template_instantiation.tmpl;
-	    tree args = r->u.template_instantiation.targs;
-	    diagnose_constraints (cloc, tmpl, args);
-	  }
+	  diagnose_constraints (cloc, fn, NULL_TREE);
 	  break;
 	case rr_inherited_ctor:
 	  inform (cloc, "  an inherited constructor is not a candidate for "
@@ -4532,25 +4515,7 @@ build_new_function_call (tree fn, vec<tree, va_gc> **args,
          through flags so that later we can use it to decide whether to warn
          about peculiar null pointer conversion.  */
       if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
-        {
-          /* If overload resolution selects a specialization of a
-             function concept for non-dependent template arguments,
-             the expression is true if the constraints are satisfied
-             and false otherwise.
-
-             NOTE: This is an extension of Concepts Lite TS that
-             allows constraints to be used in expressions. */
-          if (flag_concepts && !processing_template_decl)
-            {
-              tree tmpl = DECL_TI_TEMPLATE (cand->fn);
-              tree targs = DECL_TI_ARGS (cand->fn);
-              tree decl = DECL_TEMPLATE_RESULT (tmpl);
-              if (DECL_DECLARED_CONCEPT_P (decl))
-                return evaluate_function_concept (decl, targs);
-            }
-
-          flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
-        }
+        flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
 
       result = build_over_call (cand, flags, complain);
     }
@@ -10828,8 +10793,11 @@ joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn,
 	return winner;
     }
 
-  // C++ Concepts
-  // or, if not that, F1 is more constrained than F2.
+  /* Concepts: ... or, if not that, F1 is more constrained than F2.
+
+     FIXME: For function templates with no winner, this subsumption may
+     be computed a separate time.  This needs to be validated, and if
+     so, the redundant check removed.  */
   if (flag_concepts && DECL_P (cand1->fn) && DECL_P (cand2->fn))
     {
       winner = more_constrained (cand1->fn, cand2->fn);