[Bug bootstrap/60830] New: ICE on bootstrapping on cygwin

["gcc at Denis-Excoffier dot org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60830

            Bug ID: 60830
           Summary: ICE on bootstrapping on cygwin
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gcc@Denis-Excoffier.org

Installed gcc-4.9.0-RC-20140411 on darwin (Mavericks) with no problem. But:

On Cygwin 1.7.29-2 (+ latests patches), platform=i686-pc-cygwin (Windows XP
SP3, 32 bits), bootstrap stops with:

xgcc: internal compiler error: Segmentation fault (program cc1)
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
configure: error: in `/tmp/lcl/tmp/gcc/obj/i686-pc-cygwin/libgcc':
configure: error: cannot compute suffix of object files: cannot compile
See `config.log' for more details.
make[2]: *** [configure-stage2-target-libgcc] Error 1
make[1]: *** [stage2-bubble] Error 2
make: *** [all] Error 2


Indeed, inside /tmp/lcl/tmp/obj/gcc:
% echo "int main() { return 0; }" > foo.c
% cc1 -quiet -o foo.c foo.c
foo.c:1:1: internal compiler error: Aborted
 int main() { return 0; }
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
%

The foo.o seems ok. After some investigation, it seems that cc1 receives an
unexpected SIGABRT signal, after the end of main(), and strace confirms the
kill:
% strace -o /tmp/1 cc1 -quiet -o foo.o foo.c
(same messages as above)
% cat /tmp/1
...
 344 4823227 [main] cc1 3768 close: 0 = close(3)
2019 4825246 [main] cc1 3768 set_signal_mask: setmask 0, newmask FFFEFEDK,
mask_bits 0
  23 4825269 [main] cc1 3768 kill0: kill (3768, 6)
  22 4825291 [main] cc1 3768 sig_send: sendsig 0x784, pid 3768, signal 6,
its_me 1
...
%


On the other hand, if foo.c is erroneous, all seems ok:
% echo "it main() { return 0; }" > foo.c
foo.c:1:1: error: unknown type name 'it'
 it main() { return 0; }
 ^
foo.c:1: confused by earlier errors, bailing out
%

I don't know what to do next.