On February 8, 2021 10:44:26 PM GMT+01:00, Mikael Pettersson via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>PR98860 is a gcc-11 regression where bootstrap fails on Windows since
>the switch to enable DWARF5 by default. The symptoms are that
>executables generated by the stage1 compiler fail to run with "Exec
>format error", which confuses subsequent configure steps and causes
>hard errors. This happens even with the very latest binutils master.
>
>Fixed by updating SUBTARGET_OVERRIDE_OPTIONS to set dwarf_version to 4
>unless the user explicitly requested another version. I see some other
>targets did the same.
>
>Tested on Cygwin64 and mingw-w64.
>
>Ok for master?
It might be better to expose the default via configure (I've heard desires to
control that elsewhere).
Richard.
>2021-02-08 Mikael Pettersson <mikpeli...@gmail.com>
>
> PR bootstrap/98860
> * config/i386/cygming.h (SUBTARGET_OVERRIDE_OPTIONS): Override
> dwarf_version to 4.
>
>--- a/gcc/config/i386/cygming.h
>+++ b/gcc/config/i386/cygming.h
>@@ -209,6 +209,9 @@ along with GCC; see the file COPYING3. If not see
>#define SUBTARGET_OVERRIDE_OPTIONS
>\
>do {
>\
>flag_pic = TARGET_64BIT ? 1 : 0; \
>+ /* DWARF5 currently does not work on Windows. */
>\
>+ if (!global_options_set.x_dwarf_version)
>\
>+ dwarf_version = 4;
>\
> } while (0)
>
> /* Define this macro if references to a symbol must be treated
