From: Patrick Palka <ppalka@redhat.com>
Date: Tue, 20 Jan 2026 20:25:07 +0000 (-0500)
Subject: c++: non-dep reversed <=> returning int [PR123601]
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9fdccdaa54a176fc710972fa65caadee57b5f9c3;p=thirdparty%2Fgcc.git

c++: non-dep reversed <=> returning int [PR123601]

The code path for non-dependent operator expressions rewritten from a
<=> returning a non-class type (added in r16-3727-gf2fddc4b84a843) is
also reached for a reversed such <=> expression with the form
0 @ (y <=> x) where the @ is <=>, so we need to relax the relevant
assert accordingly.

	PR c++/123601

gcc/cp/ChangeLog:

	* tree.cc (build_min_non_dep_op_overload): Relax
	COMPARISON_CLASS_P assert to accept SPACESHIP_EXPR too.

gcc/testsuite/ChangeLog:

	* g++.dg/lookup/operator-9.C: New test.
---

diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
index 030af4d219d..ab9d0d532f5 100644
--- a/gcc/cp/tree.cc
+++ b/gcc/cp/tree.cc
@@ -3849,7 +3849,8 @@ build_min_non_dep_op_overload (enum tree_code op,
 
 	  if (TREE_CODE (non_dep) != CALL_EXPR)
 	    {
-	      gcc_checking_assert (COMPARISON_CLASS_P (non_dep));
+	      gcc_checking_assert (COMPARISON_CLASS_P (non_dep)
+				   || TREE_CODE (non_dep) == SPACESHIP_EXPR);
 	      if (reversed)
 		std::swap (op0, op1);
 	      return build_min_non_dep (TREE_CODE (non_dep), non_dep, op0, op1);
diff --git a/gcc/testsuite/g++.dg/lookup/operator-9.C b/gcc/testsuite/g++.dg/lookup/operator-9.C
new file mode 100644
index 00000000000..6c9326ec050
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/operator-9.C
@@ -0,0 +1,17 @@
+// PR c++/123601
+// { dg-do compile { target c++20 } }
+
+#include <compare>
+
+struct A {
+  bool operator==(int);
+  int operator<=>(int);
+};
+
+template<class T>
+void f() {
+  A a;
+  (void)(0 <=> a);
+}
+
+template void f<int>();