Looks like I mispelled "Merrill". Here is the corrected patch.
-Ben
On Mon, Aug 18, 2025 at 7:31 PM Ben Wu <soggysocks...@gmail.com> wrote:
> Sorry about that, I'm not sure why the formatting issues are there.
> Gmail seems to remove tabs from the patch as well. I attached the
> revised patch in case this patch still has some formatting problems like
> the indentation for error_at.
>
> I have adjusted the testcases to use dg-prune-output and bootstrapped and
> tested on x86_64-linux-gnu.
>
> Thanks,
> -Ben
>
>
> This testcase caused an ICE when mangling the invalid type-constraint in
> write_requirement since write_type_constraint expects a TEMPLATE_TYPE_PARM.
>
> Setting the trailing return type to NULL_TREE when a
> return-type-requirement is found in place of a type-constraint prevents the
> failed assertion in write_requirement. It also allows the invalid
> constraint to be satisfied in some contexts to prevent redundant errors,
> e.g. in concepts-requires5.C.
>
> Bootstrapped and tested on x86_64-linux-gnu.
>
> Could someone help review and commit?
> Thanks.
>
> PR c++/120618
>
> gcc/cp/ChangeLog:
>
> * parser.cc (cp_parser_compound_requirement): Set type to
> NULL_TREE for invalid type-constraint.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/cpp2a/concepts-requires5.C: Don't require
> redundant diagnostic in static assertion.
> * g++.dg/concepts/pr120618.C: New test.
>
> Suggested-by: Jason Merril <ja...@redhat.com>
> ---
> gcc/cp/parser.cc | 9 ++++++---
> gcc/testsuite/g++.dg/concepts/pr120618.C | 13 +++++++++++++
> gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C | 2 +-
> 3 files changed, 20 insertions(+), 4 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/concepts/pr120618.C
>
> diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
> index d66b658b748..40223bedcc1 100644
> --- a/gcc/cp/parser.cc
> +++ b/gcc/cp/parser.cc
> @@ -33403,9 +33403,12 @@ cp_parser_compound_requirement (cp_parser *parser)
> }
> }
> else
> - /* P1452R2 removed the trailing-return-type option. */
> - error_at (type_loc,
> - "return-type-requirement is not a type-constraint");
> + {
> + /* P1452R2 removed the trailing-return-type option. */
> + error_at (type_loc,
> + "return-type-requirement is not a type-constraint");
> + type = NULL_TREE;
> + }
> }
>
> location_t loc = make_location (expr_token->location,
> diff --git a/gcc/testsuite/g++.dg/concepts/pr120618.C
> b/gcc/testsuite/g++.dg/concepts/pr120618.C
> new file mode 100644
> index 00000000000..85d2532a9d6
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/concepts/pr120618.C
> @@ -0,0 +1,13 @@
> +// { dg-do compile { target c++17 } }
> +// { dg-options "-fconcepts" }
> +
> +class B{};
> +
> +template <typename T>
> +requires (!requires(T t) { { t } -> bool; }) // { dg-error
> "return-type-requirement is not a type-constraint" }
> +void foo(T t) {}
> +
> +int main() {
> + B b;
> + foo(b); // { dg-prune-output "no matching function" }
> +}
> diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C
> b/gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C
> index 524eadbf5dd..3c5a9135c18 100644
> --- a/gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C
> +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C
> @@ -41,5 +41,5 @@ class D : /*private*/ B { };
> void driver_2()
> {
> static_assert(ConvertibleTo<D, B>()); // { dg-error "cannot call" }
> - static_assert(ConvertibleTo<D, B>); // { dg-error "static assertion
> failed" }
> + static_assert(ConvertibleTo<D, B>); // { dg-prune-output "static
> assertion failed" }
> }
> --
> 2.43.0
>
From 30b1cea7e42b1af4856fea286ec4db9ef22a3fb6 Mon Sep 17 00:00:00 2001
From: Ben Wu <soggysocks...@gmail.com>
Date: Mon, 18 Aug 2025 17:00:17 -0700
Subject: [PATCH v3] c++: Fix ICE on mangling invalid compound requirement
[PR120618]
This testcase caused an ICE when mangling the invalid type-constraint in
write_requirement since write_type_constraint expects a TEMPLATE_TYPE_PARM.
Setting the trailing return type to NULL_TREE when a
return-type-requirement is found in place of a type-constraint prevents the
failed assertion in write_requirement. It also allows the invalid
constraint to be satisfied in some contexts to prevent redundant errors,
e.g. in concepts-requires5.C.
Bootstrapped and tested on x86_64-linux-gnu.
Could someone help review and commit?
Thanks.
PR c++/120618
gcc/cp/ChangeLog:
* parser.cc (cp_parser_compound_requirement): Set type to
NULL_TREE for invalid type-constraint.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-requires5.C: Don't require
redundant diagnostic in static assertion.
* g++.dg/concepts/pr120618.C: New test.
Suggested-by: Jason Merrill <ja...@redhat.com>
---
gcc/cp/parser.cc | 9 ++++++---
gcc/testsuite/g++.dg/concepts/pr120618.C | 13 +++++++++++++
gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C | 2 +-
3 files changed, 20 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/concepts/pr120618.C
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index d66b658b748..40223bedcc1 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -33403,9 +33403,12 @@ cp_parser_compound_requirement (cp_parser *parser)
}
}
else
- /* P1452R2 removed the trailing-return-type option. */
- error_at (type_loc,
- "return-type-requirement is not a type-constraint");
+ {
+ /* P1452R2 removed the trailing-return-type option. */
+ error_at (type_loc,
+ "return-type-requirement is not a type-constraint");
+ type = NULL_TREE;
+ }
}
location_t loc = make_location (expr_token->location,
diff --git a/gcc/testsuite/g++.dg/concepts/pr120618.C b/gcc/testsuite/g++.dg/concepts/pr120618.C
new file mode 100644
index 00000000000..85d2532a9d6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/concepts/pr120618.C
@@ -0,0 +1,13 @@
+// { dg-do compile { target c++17 } }
+// { dg-options "-fconcepts" }
+
+class B{};
+
+template <typename T>
+requires (!requires(T t) { { t } -> bool; }) // { dg-error "return-type-requirement is not a type-constraint" }
+void foo(T t) {}
+
+int main() {
+ B b;
+ foo(b); // { dg-prune-output "no matching function" }
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C b/gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C
index 524eadbf5dd..3c5a9135c18 100644
--- a/gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-requires5.C
@@ -41,5 +41,5 @@ class D : /*private*/ B { };
void driver_2()
{
static_assert(ConvertibleTo<D, B>()); // { dg-error "cannot call" }
- static_assert(ConvertibleTo<D, B>); // { dg-error "static assertion failed" }
+ static_assert(ConvertibleTo<D, B>); // { dg-prune-output "static assertion failed" }
}
--
2.43.0
