diff mbox series

c++: Dependent conversion operator in concept [PR94597]

Message ID 20200421135552.1818433-1-ppalka@redhat.com
State New
Headers show
Series c++: Dependent conversion operator in concept [PR94597] | expand

Commit Message

Patrick Palka April 21, 2020, 1:55 p.m. UTC
When building the parameter mapping for an atomic constraint,
find_template_parameters does not spot the template parameter within the
conversion-type-id of a dependent conversion operator, which later leads to an
ICE during substitution when looking up the missing template argument for this
unnoticed template parameter.

(The below testcase is a modification of the reduced testcase in the PR, adding
parens to the requirement 'e.operator c;' as a workaround for PR94645.)

Boostrapped and regtested on x86_64-pc-linux-gnu, does this look OK to commit?

gcc/cp/ChangeLog:

	PR c++/94597
	* pt.c (any_template_parm_r) <case IDENTIFIER_NODE>: New case.  If this
	is a conversion operator, visit its TREE_TYPE.

gcc/testsuite/ChangeLog:

	PR c++/94597
	* g++.dg/cpp2a/concepts-conv2.C: New test.
---
 gcc/cp/pt.c                                 |  6 ++++++
 gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C | 19 +++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C

Comments

Jason Merrill April 21, 2020, 2:47 p.m. UTC | #1
On 4/21/20 9:55 AM, Patrick Palka wrote:
> When building the parameter mapping for an atomic constraint,
> find_template_parameters does not spot the template parameter within the
> conversion-type-id of a dependent conversion operator, which later leads to an
> ICE during substitution when looking up the missing template argument for this
> unnoticed template parameter.
> 
> (The below testcase is a modification of the reduced testcase in the PR, adding
> parens to the requirement 'e.operator c;' as a workaround for PR94645.)
> 
> Boostrapped and regtested on x86_64-pc-linux-gnu, does this look OK to commit?

OK.

> gcc/cp/ChangeLog:
> 
> 	PR c++/94597
> 	* pt.c (any_template_parm_r) <case IDENTIFIER_NODE>: New case.  If this
> 	is a conversion operator, visit its TREE_TYPE.
> 
> gcc/testsuite/ChangeLog:
> 
> 	PR c++/94597
> 	* g++.dg/cpp2a/concepts-conv2.C: New test.
> ---
>   gcc/cp/pt.c                                 |  6 ++++++
>   gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C | 19 +++++++++++++++++++
>   2 files changed, 25 insertions(+)
>   create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C
> 
> diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
> index cd6392aca22..2111f031d9e 100644
> --- a/gcc/cp/pt.c
> +++ b/gcc/cp/pt.c
> @@ -10529,6 +10529,12 @@ any_template_parm_r (tree t, void *data)
>         }
>         break;
>   
> +    case IDENTIFIER_NODE:
> +      if (IDENTIFIER_CONV_OP_P (t))
> +	/* The conversion-type-id of a conversion operator may be dependent.  */
> +	WALK_SUBTREE (TREE_TYPE (t));
> +      break;
> +
>       default:
>         break;
>       }
> diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C b/gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C
> new file mode 100644
> index 00000000000..abe68187cce
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C
> @@ -0,0 +1,19 @@
> +// PR c++/94597
> +// { dg-do compile { target c++2a } }
> +
> +template <typename b, typename c> concept d = requires(b e) { e.operator c(); };
> +
> +template <typename f, typename g> requires(d<f, g>) bool equal(f, g);
> +
> +template <typename h> struct i {
> +  i(h);
> +  operator h();
> +};
> +
> +static_assert(d<i<float>, float>);
> +static_assert(!d<i<float>, int>);
> +
> +bool fun() {
> +  i a(2.0f);
> +  return equal(a, 3.0f);
> +}
>
diff mbox series

Patch

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index cd6392aca22..2111f031d9e 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -10529,6 +10529,12 @@  any_template_parm_r (tree t, void *data)
       }
       break;
 
+    case IDENTIFIER_NODE:
+      if (IDENTIFIER_CONV_OP_P (t))
+	/* The conversion-type-id of a conversion operator may be dependent.  */
+	WALK_SUBTREE (TREE_TYPE (t));
+      break;
+
     default:
       break;
     }
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C b/gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C
new file mode 100644
index 00000000000..abe68187cce
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-conv2.C
@@ -0,0 +1,19 @@ 
+// PR c++/94597
+// { dg-do compile { target c++2a } }
+
+template <typename b, typename c> concept d = requires(b e) { e.operator c(); };
+
+template <typename f, typename g> requires(d<f, g>) bool equal(f, g);
+
+template <typename h> struct i {
+  i(h);
+  operator h();
+};
+
+static_assert(d<i<float>, float>);
+static_assert(!d<i<float>, int>);
+
+bool fun() {
+  i a(2.0f);
+  return equal(a, 3.0f);
+}