From 1e0f37df1b12cd91a6dbb523f5c722f9a961edaa Mon Sep 17 00:00:00 2001
From: Patrick Palka <ppalka@redhat.com>
Date: Tue, 18 Jul 2023 09:21:40 -0400
Subject: [PATCH] c++: constrained surrogate call functions [PR110535]
We weren't checking constraints on pointer/reference-to-function conversion
functions during overload resolution, which caused us to ICE on the first
testcase and reject the second testcase.
PR c++/110535
gcc/cp/ChangeLog:
* call.cc (add_conv_candidate): Check constraints.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-surrogate1.C: New test.
* g++.dg/cpp2a/concepts-surrogate2.C: New test.
---
gcc/cp/call.cc | 8 ++++++++
gcc/testsuite/g++.dg/cpp2a/concepts-surrogate1.C | 12 ++++++++++++
gcc/testsuite/g++.dg/cpp2a/concepts-surrogate2.C | 14 ++++++++++++++
3 files changed, 34 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-surrogate1.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-surrogate2.C
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index 976330cd23f8..24f93dd983ca 100644
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -2588,6 +2588,14 @@ add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
if (*candidates && (*candidates)->fn == totype)
return NULL;
+ if (!constraints_satisfied_p (fn))
+ {
+ reason = constraint_failure ();
+ viable = 0;
+ return add_candidate (candidates, fn, obj, arglist, len, convs,
+ access_path, conversion_path, viable, reason, flags);
+ }
+
for (i = 0; i < len; ++i)
{
tree arg, argtype, convert_type = NULL_TREE;
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-surrogate1.C b/gcc/testsuite/g++.dg/cpp2a/concepts-surrogate1.C
new file mode 100644
index 000000000000..e8481a316568
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-surrogate1.C
@@ -0,0 +1,12 @@
+// PR c++/110535
+// { dg-do compile { target c++20 } }
+
+using F = int(int);
+
+template<bool B>
+struct A {
+ operator F*() requires B;
+};
+
+int i = A<true>{}(0); // OK
+int j = A<false>{}(0); // { dg-error "no match" }
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-surrogate2.C b/gcc/testsuite/g++.dg/cpp2a/concepts-surrogate2.C
new file mode 100644
index 000000000000..8bf8364beb72
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-surrogate2.C
@@ -0,0 +1,14 @@
+// PR c++/110535
+// { dg-do compile { target c++20 } }
+
+using F = int(int);
+using G = long(int);
+
+template<bool B>
+struct A {
+ operator F&() requires B;
+ operator G&() requires (!B);
+};
+
+int i = A<true>{}(0); // { dg-bogus "ambiguous" }
+int j = A<false>{}(0); // { dg-bogus "ambiguous" }
--
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