gfortran, OpenMP and static linking

[Harald Anlauf <anlauf@gmx.de>]

Dear all,

is there a reason that one should not be able to statically link a
Fortran binary that has been compiled with -fopenmp?

A tiny example seems to fail for me with all gfortran versions:

program p
!$omp parallel
!$omp end parallel
end

% gfortran -fopenmp foo.f90 -g -static
% OMP_NUM_THREADS=1 ./a.out

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.
[...]

Running under gdb:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) bt
#0  0x0000000000000000 in ?? ()
#1  0x0000000000405198 in __gthread_mutex_destroy (__mutex=0x72ced8)
    at ../libgcc/gthr-default.h:739
#2  destroy_unit_mutex (u=0x72ce00) at ../../../libgfortran/io/unit.c:252
#3  close_unit_1 (u=0x72ce00, locked=locked@entry=1) at ../../../libgfortran/io/unit.c:743
#4  0x0000000000405202 in _gfortrani_close_units () at ../../../libgfortran/io/unit.c:780
#5  0x000000000044c53c in __libc_csu_fini () at elf-init.c:100
#6  0x0000000000452ef0 in __run_exit_handlers (status=0, listp=0x720630 <__exit_funcs>,
    run_list_atexit=run_list_atexit@entry=true, run_dtors=run_dtors@entry=true) at exit.c:83
#7  0x0000000000452f4a in exit (status=<optimized out>) at exit.c:105
#8  0x000000000044bdc6 in __libc_start_main (main=0x4030bd <main>, argc=1,
    argv=0x7fffffffc348, init=0x44c470 <__libc_csu_init>, fini=0x44c510 <__libc_csu_fini>,
    rtld_fini=0x0, stack_end=0x7fffffffc338) at ../csu/libc-start.c:342
#9  0x0000000000402fba in _start () at ../sysdeps/x86_64/start.S:120


I suspect either a locking issue for unit_root in unit.c, or maybe bad
initialization of it, but haven't stared long enough at the code.
According to git blame almost all related references date back to 2005.

Shall I open a PR against libfortran?  Or is there something I am missing?

Thanks,
Harald