Jason,
this is the patch you suggested, as I understood it. I kept
finish_nested_require's saving of the (converted)
current_template_parms, becase of the comment about use in diagnostics.
Is this what you meant?
boostrapped on x86_64-linux.
nathan
--
Nathan Sidwell
2020-04-27 Jason Merrill <ja...@redhat.com>
Nathan Sidwell <nat...@acm.org>
PR c++/94827
* constraint.cc (map_arguments): If ARGS is null, it's a
self-mapping of parms.
(finish_nested_requirement): Do not pass argified
current_template_parms to normalization.
diff --git c/gcc/cp/constraint.cc w/gcc/cp/constraint.cc
index 06161b8c8c4..a6009dc0c47 100644
--- c/gcc/cp/constraint.cc
+++ w/gcc/cp/constraint.cc
@@ -546,12 +546,16 @@ static tree
map_arguments (tree parms, tree args)
{
for (tree p = parms; p; p = TREE_CHAIN (p))
- {
- int level;
- int index;
- template_parm_level_and_index (TREE_VALUE (p), &level, &index);
- TREE_PURPOSE (p) = TMPL_ARG (args, level, index);
- }
+ if (args)
+ {
+ int level;
+ int index;
+ template_parm_level_and_index (TREE_VALUE (p), &level, &index);
+ TREE_PURPOSE (p) = TMPL_ARG (args, level, index);
+ }
+ else
+ TREE_PURPOSE (p) = TREE_VALUE (p);
+
return parms;
}
@@ -2953,12 +2957,15 @@ finish_compound_requirement (location_t loc, tree expr, tree type, bool noexcept
tree
finish_nested_requirement (location_t loc, tree expr)
{
+ /* Currently open template headers have dummy arg vectors, so don't
+ pass into normalization. */
+ tree norm = normalize_constraint_expression (expr, NULL_TREE, false);
+ tree args = current_template_parms
+ ? template_parms_to_args (current_template_parms) : NULL_TREE;
+
/* Save the normalized constraint and complete set of normalization
arguments with the requirement. We keep the complete set of arguments
around for re-normalization during diagnostics. */
- tree args = current_template_parms
- ? template_parms_to_args (current_template_parms) : NULL_TREE;
- tree norm = normalize_constraint_expression (expr, args, false);
tree info = build_tree_list (args, norm);
/* Build the constraint, saving its normalization as its type. */
diff --git c/gcc/testsuite/g++.dg/concepts/pr94827.C w/gcc/testsuite/g++.dg/concepts/pr94827.C
new file mode 100644
index 00000000000..a6c147bf303
--- /dev/null
+++ w/gcc/testsuite/g++.dg/concepts/pr94827.C
@@ -0,0 +1,7 @@
+// PR 94287 ICE looking inside open template-parm level
+// { dg-do compile { target c++17 } }
+// { dg-options -fconcepts }
+template <typename T,
+ bool = requires { requires (sizeof(T)==0); } >
+void foo(T) {}
+
