On Fri, 23 Feb 2024 at 10:13, Christophe Lyon
<christophe.l...@linaro.org> wrote:
>
> On Fri, 23 Feb 2024 at 09:42, Jakub Jelinek <ja...@redhat.com> wrote:
> >
> > 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.
>
> Hi Jakub,
>
> Sadly our precommit CI could not apply your patch automatically (as
> you can see in patchwork).
>
> I'll test your patch manually.
>
I can now confirm that the new test passes on arm (native
armv8l-unknown-linux-gnueabihf), and no regression.
Thanks,
Christophe
> Thanks,
>
> Christophe
>
> >
> > 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
> >
