On 4/30/20 10:18 AM, Jason Merrill wrote:
On 4/29/20 2:50 PM, Nathan Sidwell wrote:
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?
Yes, this looks fine.
But I don't think that we need to keep saving the converted
current_template_parms; diagnostics could also normalize using NULL_TREE
args. And it looks like diagnose_nested_requirement isn't currently
doing re-normalization anyway. This doesn't need to block the release,
though.
Ok, I'll deal with that post-release.
Here's a modified version. The only change is to remove an assert in
tsubst_nested_requirement. We have an arg_vec of 2, but only the first
is filled in. Thus we think the NULL one is a dependent type.
The testcase checks we evaluate the default arg as expected.
I don't expect the bootstrap to fail, because this is removing an assert.
nathan
--
Nathan Sidwell
2020-04-30 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.
(tsubst_nested_requirement): Don't assert no template parms.
diff --git c/gcc/cp/constraint.cc w/gcc/cp/constraint.cc
index 06161b8c8c4..5e732bb9b81 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;
}
@@ -2005,8 +2009,6 @@ tsubst_compound_requirement (tree t, tree args, subst_info info)
static tree
tsubst_nested_requirement (tree t, tree args, subst_info info)
{
- gcc_assert (!uses_template_parms (args));
-
/* Ensure that we're in an evaluation context prior to satisfaction. */
tree norm = TREE_VALUE (TREE_TYPE (t));
tree result = satisfy_constraint (norm, args, info);
@@ -2953,12 +2955,15 @@ 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..f14ec2551a1
--- /dev/null
+++ w/gcc/testsuite/g++.dg/concepts/pr94827.C
@@ -0,0 +1,15 @@
+// PR 94287 ICE looking inside open template-parm level
+// { dg-do run { target c++17 } }
+// { dg-options -fconcepts }
+
+template <typename T,
+ bool X = requires { requires (sizeof(T)==1); } >
+ int foo(T) { return X; }
+
+int main() {
+ if (!foo('4'))
+ return 1;
+ if (foo (4))
+ return 2;
+ return 0;
+}
