RFC: Leave preprocessed files on ICE

[Thomas Koenig]

Am 07.01.25 um 17:52 schrieb Jakub Jelinek via Gcc:
> But the compiler does in every ICE message in which -freport-bug isn't
> enabled.

It seems that -freport-bug does nothing for Fortran, or at least the
Fortran front end (which why it was unfamiliar to me). Grabbing a
random ICE off bugzilla, slightliy modifying it so the preprocessor
is actually invoked, one gets:

$ cat z1.F90
#define N 1

program p
    type t
       character :: a
       integer :: b
       integer :: c(t(N))
    end type
    type(t) :: z = t('a', 2, [3])
end
$ gfortran -freport-bug -c z1.F90
z1.F90:9:28:

     9 |    type(t) :: z = t('a', 2, [3])
       |                            1
Error: Bad array spec of component 'c' referenced in structure 
constructor at (1)
f951: internal compiler error: Segmentation fault
0x276239f internal_error(char const*, ...)
         ../../trunk/gcc/diagnostic-global-context.cc:517
0x11f33b6 crash_signal
         ../../trunk/gcc/toplev.cc:322
[...]
0xaec6d8 gfc_parse_file()
         ../../trunk/gcc/fortran/parse.cc:7368
0xb48d0f gfc_be_parse_file
         ../../trunk/gcc/fortran/f95-lang.cc:241
Please submit a full bug report, with preprocessed source.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

That's the bug, presumably.  I've filed PR 118336 for this.
(And mentioning -freport-bug in the docs is PR 104254, but
it is better to leave that as is because gfortran's
error message points there).

Best regards

	Thomas