On 1/30/24 10:09, Patrick Palka wrote:
Bootstrapped and regtested on x86_64-pc-linu-xgnu, does this
look OK for trunk?
OK.
-- >8 --
We miscompile the below testcase because keep_unused_object_arg
duplicates the side effects of a (by-value) object argument of a
xobj member function.
PR c++/113640
gcc/cp/ChangeLog:
* call.cc (keep_unused_object_arg): Punt for an xobj member
function.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/explicit-obj-lambda14.C: New test.
---
gcc/cp/call.cc | 2 +-
.../g++.dg/cpp23/explicit-obj-lambda14.C | 27 +++++++++++++++++++
2 files changed, 28 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp23/explicit-obj-lambda14.C
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index 9de0d77c423..451a189f7cf 100644
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -5256,7 +5256,7 @@ keep_unused_object_arg (tree result, tree obj, tree fn)
{
if (result == NULL_TREE
|| result == error_mark_node
- || TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
+ || DECL_OBJECT_MEMBER_FUNCTION_P (fn)
|| !TREE_SIDE_EFFECTS (obj))
return result;
diff --git a/gcc/testsuite/g++.dg/cpp23/explicit-obj-lambda14.C b/gcc/testsuite/g++.dg/cpp23/explicit-obj-lambda14.C
new file mode 100644
index 00000000000..03dededfe33
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp23/explicit-obj-lambda14.C
@@ -0,0 +1,27 @@
+// PR c++/113640
+// { dg-do run { target c++23 } }
+
+static int total;
+
+struct A {
+ A f(this auto self, int n) {
+ total += n;
+ return self;
+ }
+};
+
+int main() {
+ A a;
+ a.f(1).f(42).f(100);
+ if (total != 143)
+ __builtin_abort();
+
+ total = 0;
+ auto l = [](this auto self, int n) {
+ total += n;
+ return self;
+ };
+ l(1)(42)(100);
+ if (total != 143)
+ __builtin_abort();
+}