[gcc r13-1784] c++: defaulted friend op== [PR106361]

[Jason Merrill <jason@gcc.gnu.org>]

https://gcc.gnu.org/g:28be481cf47d52af8b11972d2394226bbaf87867

commit r13-1784-g28be481cf47d52af8b11972d2394226bbaf87867
Author: Jason Merrill <jason@redhat.com>
Date:   Wed Jul 20 20:00:58 2022 -0400

    c++: defaulted friend op== [PR106361]
    
    Now non-member functions can be defaulted, so this assert is wrong.
    move_signature_fn_p already checks for ctor or op=.
    
            PR c++/106361
    
    gcc/cp/ChangeLog:
    
            * decl.cc (move_fn_p): Remove assert.
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/cpp2a/spaceship-eq14.C: New test.

Diff:
---
 gcc/cp/decl.cc                              |  2 --
 gcc/testsuite/g++.dg/cpp2a/spaceship-eq14.C | 17 +++++++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index aa6cf3c6c2e..70ad681467e 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -15022,8 +15022,6 @@ copy_fn_p (const_tree d)
 bool
 move_fn_p (const_tree d)
 {
-  gcc_assert (DECL_FUNCTION_MEMBER_P (d));
-
   if (cxx_dialect == cxx98)
     /* There are no move constructors if we are in C++98 mode.  */
     return false;
diff --git a/gcc/testsuite/g++.dg/cpp2a/spaceship-eq14.C b/gcc/testsuite/g++.dg/cpp2a/spaceship-eq14.C
new file mode 100644
index 00000000000..896e5232bf6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/spaceship-eq14.C
@@ -0,0 +1,17 @@
+// PR c++/106361
+// { dg-do compile { target c++20 } }
+
+struct foo {
+  int x;
+};
+
+struct bar {
+  foo f;			// { dg-error "operator==" }
+  friend bool operator==(const bar& a, const bar& b);
+};
+
+bool operator==(const bar& a, const bar& b) = default;
+
+int main() {
+  return bar{} == bar{};	// { dg-error "deleted" }
+}