[Bug fortran/112700] New: Segmentation fault with list of characters and types

[Bug fortran/112700] New: Segmentation fault with list of characters and types

[alexandre.poux at coria dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112700

            Bug ID: 112700
           Summary: Segmentation fault with list of characters and types
           Product: gcc
           Version: 13.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: alexandre.poux at coria dot fr
  Target Milestone: ---

Created attachment 56679
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56679&action=edit
a module triggerring a segmentation fault

The attached source code for a fortran module triggers a segmentation fault
when compiling

```
bug_mod.f90:24:39:

   24 |         list_char = obj%get_char_list()
      |                                       1
internal compiler error: Segmentation fault
0xd432a1 internal_error(char const*, ...)
        ???:0
0xe409f5 fold_convert_loc(unsigned int, tree_node*, tree_node*)
        ???:0
0x15e8f14 gfc_trans_create_temp_array(stmtblock_t*, stmtblock_t*, gfc_ss*,
tree_node*, tree_node*, bool, bool, bool, locus*)
        ???:0
0x1631d79 gfc_conv_procedure_call(gfc_se*, gfc_symbol*, gfc_actual_arglist*,
gfc_expr*, vec<tree_node*, va_gc, vl_embed>*)
        ???:0
0x15f5151 gfc_conv_loop_setup(gfc_loopinfo*, locus*)
        ???:0
0x161d4f8 gfc_generate_function_code(gfc_namespace*)
        ???:0
0x15e7f29 gfc_generate_module_code(gfc_namespace*)
        ???:0
0x157973b gfc_parse_file()
        ???:0
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-11/README.Bugs> for instructions.
```

I've been able to reproduce it with
- latest version of gfortran from the archlinux repository: core/gcc-fortran
13.2.1-3
- older version from ubuntu 22.04 : Ubuntu 11.4.0-1ubuntu1~22.04

[Bug fortran/112700] Segmentation fault with list of characters and types

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112700

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-11-24
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |ice-on-valid-code

--- Comment #1 from anlauf at gcc dot gnu.org ---
The testcase has some similarity with reduced versions of pr93678
and also the same traceback.  Thus likely related.

Note: replacing the rank-1 result variable

    character(len=1) :: list(1)

by a scalar

    character(len=1) :: list !(1)

avoids the ICE.

[Bug fortran/112700] Segmentation fault with list of characters and types

[alexandre.poux at coria dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112700

--- Comment #2 from Alexandre Poux <alexandre.poux at coria dot fr> ---
Among the things that avoid the ICE:
- Using a subroutine instead of a function
- not using a type procedure but a regular function
- wrapping the list of char in a custom type
- returning a list of a real numbers

Among the things that do not avoid the ICE:
- replacing the fixed length array with a pointer or an allocatable