Hi!
When targetm.cxx.cdtor_returns_this () (aka on arm32 TARGET_AAPCS_BASED)
constructor is supposed to return this pointer, but when we cp_fold such
a call, we don't take that into account and just INIT_EXPR the object,
so we can later ICE during gimplification, because the expression doesn't
have the right type.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux and
tested with a cross to armv7-linux-gnueabi on the testcase, but
unfortunately there are no 32-bit arm boxes in cfarm and arm32 is gone from
Fedora for quite some time as well, so I have no easy way to test this.
Christophe, do you think you could test this? Thanks.
2024-02-23 Jakub Jelinek <ja...@redhat.com>
PR c++/113083
* cp-gimplify.cc (cp_fold): For targetm.cxx.cdtor_returns_this ()
wrap r into a COMPOUND_EXPR and return folded CALL_EXPR_ARG (x, 0).
* g++.dg/cpp0x/constexpr-113083.C: New test.
--- gcc/cp/cp-gimplify.cc.jj 2024-02-22 21:45:09.663430066 +0100
+++ gcc/cp/cp-gimplify.cc 2024-02-22 22:30:23.481428242 +0100
@@ -3412,9 +3412,15 @@ cp_fold (tree x, fold_flags_t flags)
if (DECL_CONSTRUCTOR_P (callee))
{
loc = EXPR_LOCATION (x);
- tree s = build_fold_indirect_ref_loc (loc,
- CALL_EXPR_ARG (x, 0));
+ tree a = CALL_EXPR_ARG (x, 0);
+ bool return_this = targetm.cxx.cdtor_returns_this ();
+ if (return_this)
+ a = cp_save_expr (a);
+ tree s = build_fold_indirect_ref_loc (loc, a);
r = cp_build_init_expr (s, r);
+ if (return_this)
+ r = build2_loc (loc, COMPOUND_EXPR, TREE_TYPE (x), r,
+ fold_convert_loc (loc, TREE_TYPE (x), a));
}
x = r;
break;
--- gcc/testsuite/g++.dg/cpp0x/constexpr-113083.C.jj 2024-01-13
00:05:00.077372302 +0100
+++ gcc/testsuite/g++.dg/cpp0x/constexpr-113083.C 2024-02-22
22:20:20.622618992 +0100
@@ -0,0 +1,16 @@
+// PR c++/113083
+// { dg-do compile { target c++11 } }
+// { dg-options "-Os" }
+
+struct A { constexpr A (); };
+
+void
+foo ()
+{
+ A b;
+}
+
+constexpr
+A::A ()
+{
+}
Jakub
