On Wed, Feb 11, 2026 at 03:43:54PM -0500, Patrick Palka wrote:
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look
> OK for trunk/15?
Looks ok.
> -- >8 --
>
> The object argument of an xobj memfn call needs to be evaluated before
> its formal arguments, like with an iobj memfn call. This patch
> generalizes the existing METHOD_TYPE callee evaluation order handling
> in cp_gimplify_expr to also handle xobj memfn callees. (The handling
> needs to look at both fntype and decl because the callee can be e.g. an
> OBJ_TYPE_REF for which decl would be NULL.)
>
> PR c++/123989
>
> gcc/cp/ChangeLog:
>
> * cp-gimplify.cc (cp_gimplify_expr) <case CALL_EXPR>: Evaluate
> the object argument of an xobj memfn call first too.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/cpp23/explicit-obj-eval-order.C: New test.
> ---
> gcc/cp/cp-gimplify.cc | 5 ++++-
> .../g++.dg/cpp23/explicit-obj-eval-order.C | 16 ++++++++++++++++
> 2 files changed, 20 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/g++.dg/cpp23/explicit-obj-eval-order.C
>
> diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc
> index 5ccfeefa6982..ba6a65961200 100644
> --- a/gcc/cp/cp-gimplify.cc
> +++ b/gcc/cp/cp-gimplify.cc
> @@ -921,7 +921,10 @@ cp_gimplify_expr (tree *expr_p, gimple_seq *pre_p,
> gimple_seq *post_p)
> tree fntype = TREE_TYPE (CALL_EXPR_FN (*expr_p));
> if (INDIRECT_TYPE_P (fntype))
> fntype = TREE_TYPE (fntype);
> - if (TREE_CODE (fntype) == METHOD_TYPE)
> + tree decl = cp_get_callee_fndecl_nofold (*expr_p);
> + if (TREE_CODE (fntype) == METHOD_TYPE
> + || (decl && DECL_LANG_SPECIFIC (decl)
> + && DECL_XOBJ_MEMBER_FUNCTION_P (decl)))
> {
> int nargs = call_expr_nargs (*expr_p);
> bool side_effects = false;
> diff --git a/gcc/testsuite/g++.dg/cpp23/explicit-obj-eval-order.C
> b/gcc/testsuite/g++.dg/cpp23/explicit-obj-eval-order.C
> new file mode 100644
> index 000000000000..7ce81f32cc4b
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp23/explicit-obj-eval-order.C
> @@ -0,0 +1,16 @@
> +// PR c++/123989
> +// { dg-do run { target c++23 } }
> +
> +struct A {
> + int m = 42;
> +
> + void f(this A self, int n) {
> + if (self.m != 42 || n != 43)
> + __builtin_abort();
> + }
> +};
> +
> +int main() {
> + A a;
> + a.f(++a.m);
> +}
> --
> 2.53.0.68.g864f55e190
>
Marek
