On 2/6/26 10:04 PM, Marek Polacek wrote:
On Fri, Feb 06, 2026 at 10:41:56AM +0100, Jakub Jelinek wrote:
Hi!
splice can return error_mark_node, e.g. if the evaluation of the
constant expression throws without being caught, and the error_mark_node
later on causes ICEs in various asserts.
The following patch fixes it by returning early if error_mark_node is
returned.
LGTM.
OK.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2026-02-05 Jakub Jelinek <[email protected]>
PR c++/123752
* pt.cc (tsubst_splice_expr): Return error_mark_node if
splice returned it.
* g++.dg/reflect/splice8.C: New test.
--- gcc/cp/pt.cc.jj 2026-02-05 15:14:59.078531057 +0100
+++ gcc/cp/pt.cc 2026-02-05 19:27:49.528258536 +0100
@@ -16753,6 +16753,8 @@ tsubst_splice_expr (tree t, tree args, t
if (op == error_mark_node)
return error_mark_node;
op = splice (op);
+ if (op == error_mark_node)
+ return error_mark_node;
if (dependent_splice_p (op))
{
if (SPLICE_EXPR_EXPRESSION_P (t))
--- gcc/testsuite/g++.dg/reflect/splice8.C.jj 2026-02-05 19:29:28.915578706
+0100
+++ gcc/testsuite/g++.dg/reflect/splice8.C 2026-02-05 19:28:59.850069966
+0100
@@ -0,0 +1,33 @@
+// PR c++/123752
+// { dg-do compile { target c++26 } }
+// { dg-additional-options "-freflection" }
+
+struct S { int s; };
+struct U { int u; };
+
+template <typename T>
+consteval decltype (^^int)
+foo ()
+{
+ return ^^S::s;
+}
+
+template <>
+consteval decltype (^^int)
+foo <U> ()
+{
+ throw 1;
+}
+
+template <typename T>
+auto
+bar (T x)
+{
+ return x.[: foo <T> () :]; // { dg-error "uncaught exception '1'" }
+}
+
+auto
+baz (U x)
+{
+ return bar (x);
+}
Jakub
Marek
