[Bug target/113357] [14/15 regression] m68k-linux bootstrap failure in stage2 due to segfault compiling unwind-dw2.c since r14-4664-g04c9cf5c786b94

["mikpelinux at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113357

--- Comment #13 from Mikael Pettersson <mikpelinux at gmail dot com> ---
(In reply to Mikael Pettersson from comment #9)
> (In reply to Manolis Tsamis from comment #8)
> > Created attachment 58335 [details]
> > Do not modify live_out registers
> > 
> > After looking again at the dumps from PR112415, which I believe is closely
> > related to the issue here, I saw that while f-m-o was checking the uses of
> > the folded registers, it was still modifying registers that were at the BB's
> > live_out set.
> > 
> > I have attached a patch that I'm testing for addressing this. Could you
> > please check if this fixes this issue?
> 
> I'm starting a bootstrap on m68k-linux-gnu with this now, should know by
> Friday if it resolves the issue or not. (It's running in full-system
> emulation mode on Aranym, so it's slow.)

Failed with a compile-warning-turned-error, haven't had time to investigate.

In file included from /mnt/scratch/gcc-15-20240602/gcc/system.h:726,
                 from /mnt/scratch/gcc-15-20240602/gcc/gimple-range-edge.cc:24:
In member function 'wide_int_storage& wide_int_storage::operator=(const T&)
[with T = wi::hwi_with_prec]',
    inlined from 'generic_wide_int<storage>&
generic_wide_int<T>::operator=(const T&) [with T = wi::hwi_with_prec; storage =
wide_int_storage]' at /mnt/scratch/gcc-15-20240602/gcc/wide-int.h:1002:23,
    inlined from 'void irange_bitmask::set_unknown(unsigned int)' at
/mnt/scratch/gcc-15-20240602/gcc/value-range.h:165:27,
    inlined from 'virtual void irange::set_varying(tree)' at
/mnt/scratch/gcc-15-20240602/gcc/value-range.h:1140:25,
    inlined from 'int_range<N, RESIZABLE>::int_range(tree) [with unsigned int N
= 3; bool RESIZABLE = true]' at
/mnt/scratch/gcc-15-20240602/gcc/value-range.h:1102:15,
    inlined from 'void gimple_outgoing_range::calc_switch_ranges(gswitch*)' at
/mnt/scratch/gcc-15-20240602/gcc/gimple-range-edge.cc:140:36:
/mnt/scratch/gcc-15-20240602/gcc/wide-int.h:1241:23: error:
'default_range.int_range<3,
true>::<unnamed>.irange::m_bitmask.irange_bitmask::m_value.generic_wide_int<wide_int_storage>::<unnamed>.wide_int_storage::u.wide_int_storage::<unnamed
union>::valp' may be used uninitialized [-Werror=maybe-uninitialized]
 1241 |         XDELETEVEC (u.valp);
/mnt/scratch/gcc-15-20240602/gcc/../include/libiberty.h:370:48: note: in
definition of macro 'XDELETEVEC'
  370 | #define XDELETEVEC(P)           free ((void*) (P))
      |                                                ^
/mnt/scratch/gcc-15-20240602/gcc/gimple-range-edge.cc: In member function 'void
gimple_outgoing_range::calc_switch_ranges(gswitch*)':
/mnt/scratch/gcc-15-20240602/gcc/gimple-range-edge.cc:140:17: note:
'default_range' declared here
  140 |   int_range_max default_range (type);
      |                 ^~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
make[3]: *** [Makefile:1197: gimple-range-edge.o] Error 1