[Bug fortran/99171] New: [10 Regression] Optional procedure call inside Open MP parallel loop produces Segmentation Fault

[Bug fortran/99171] New: [10 Regression] Optional procedure call inside Open MP parallel loop produces Segmentation Fault

[am41119 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99171

            Bug ID: 99171
           Summary: [10 Regression] Optional procedure call inside Open MP
                    parallel loop produces Segmentation Fault
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: am41119 at hotmail dot com
  Target Milestone: ---

Created attachment 50226
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50226&action=edit
Output of using -save-temps during compilation

When calling a passed optional procedure inside an Open MP parallel loop (even
with OMP_NUM_THREADS=1) the address of the optional procedure is no longer set
to the actual passed procedure. Because the address of the optional procedure
is no longer correct we get a Segmentation Fault when calling it.


The below program works on GCC9 and below.


main.f90:
-----------------------------------------------
program gcc10_omp_optional_bug
    implicit none

    call function_calling_optionals(print_something)

    call function_calling_optionals_in_omp(print_something)

contains

    subroutine optional_function_template()
        implicit none
    end subroutine

    subroutine print_something()
        implicit none

        print *, "Printing Something"

    end subroutine print_something

    subroutine function_calling_optionals(optional_function)
        implicit none
        procedure(optional_function_template), optional :: optional_function

        print *, "When optional function is called without Open MP directive:"

        if (present(optional_function)) then
            call optional_function()
        end if

    end subroutine function_calling_optionals

    subroutine function_calling_optionals_in_omp(optional_function)
        implicit none
        procedure(optional_function_template), optional :: optional_function

        print *, "When optional function is called inside Open MP directive:"

        !$omp parallel 
        if (present(optional_function)) then
            call optional_function()
        end if
        !$omp end parallel

    end subroutine function_calling_optionals_in_omp


end program gcc10_omp_optional_bug


---------------------------------------------
gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa:hsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
10.2.0-5ubuntu1~20.04' --with-bugurl=file:///usr/share/doc/gcc-10/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-10
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new
--enable-gnu-unique-object --disable-vtable-verify --enable-plugin
--enable-default-pie --with-system-zlib --enable-libphobos-checking=release
--with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch
--disable-werror --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none=/build/gcc-10-WJNXnb/gcc-10-10.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-10-WJNXnb/gcc-10-10.2.0/debian/tmp-gcn/usr,hsa
--without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.2.0 (Ubuntu 10.2.0-5ubuntu1~20.04)

Compile Command:
gfortran main.f90 -fopenmp -o main

Execution output:

When optional function is called without Open MP directive:
Printing Something
When optional function is called inside Open MP directive:

Program received signal SIGILL: Illegal instruction.

Program received signal SIGILL: Illegal instruction.

Program received signal SIGILL: Illegal instruction.

Backtrace for this error:

Program received signal SIGILL: Illegal instruction.

Backtrace for this error:

Backtrace for this error:

Backtrace for this error:

Program received signal SIGILL: Illegal instruction.

Backtrace for this error:

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

Backtrace for this error:

Program received signal SIGILL: Illegal instruction.

Backtrace for this error:

Program received signal SIGILL: Illegal instruction.

Backtrace for this error:
#0  0x7f9e60dd1d01 in ???
#0  0x7f9e60dd1d01 in ???
#0  0x7f9e60dd1d01 in ???
#1  0x7f9e60dd0ed5 in ???
#2  0x7f9e60bc320f in ???
#3  0x7f9e5e993e27 in ???
Illegal instruction (core dumped)

[Bug fortran/99171] [10 Regression] Optional procedure call inside Open MP parallel loop produces Segmentation Fault

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99171

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-02-20
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Confirmed on GCC10 and 11. With GCC9 the run time give

 When optional function is called without Open MP directive:
 Printing Something
 When optional function is called inside Open MP directive:
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something
 Printing Something

[Bug fortran/99171] [10/11 Regression] Optional procedure call inside Open MP parallel loop produces Segmentation Fault

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99171

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
            Summary|[10 Regression] Optional    |[10/11 Regression] Optional
                   |procedure call inside Open  |procedure call inside Open
                   |MP parallel loop produces   |MP parallel loop produces
                   |Segmentation Fault          |Segmentation Fault

[Bug fortran/99171] [10/11 Regression] Optional procedure call inside Open MP parallel loop produces Segmentation Fault

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99171

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |10.3

[Bug fortran/99171] [10/11 Regression] Optional procedure call inside Open MP parallel loop produces Segmentation Fault

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99171

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tobias Burnus <burnus@gcc.gnu.org>:

https://gcc.gnu.org/g:e9b34037cdd196ab912a7ac3358f8a8d3e307e92

commit r11-7320-ge9b34037cdd196ab912a7ac3358f8a8d3e307e92
Author: Tobias Burnus <tobias@codesourcery.com>
Date:   Mon Feb 22 13:20:26 2021 +0100

    Fortran/OpenMP: Fix optional dummy procedures [PR99171]

    gcc/fortran/ChangeLog:

            PR fortran/99171
            * trans-openmp.c (gfc_omp_is_optional_argument): Regard optional
            dummy procs as nonoptional as no special treatment is needed.

    libgomp/ChangeLog:

            PR fortran/99171
            * testsuite/libgomp.fortran/dummy-procs-1.f90: New test.

[Bug fortran/99171] [10/11 Regression] Optional procedure call inside Open MP parallel loop produces Segmentation Fault

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99171

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Tobias Burnus
<burnus@gcc.gnu.org>:

https://gcc.gnu.org/g:08f43c8c98196b2c9b9476aa20b36a3ee629b3a1

commit r10-9381-g08f43c8c98196b2c9b9476aa20b36a3ee629b3a1
Author: Tobias Burnus <tobias@codesourcery.com>
Date:   Mon Feb 22 13:20:26 2021 +0100

    Fortran/OpenMP: Fix optional dummy procedures [PR99171]

    gcc/fortran/ChangeLog:

            PR fortran/99171
            * trans-openmp.c (gfc_omp_is_optional_argument): Regard optional
            dummy procs as nonoptional as no special treatment is needed.

    libgomp/ChangeLog:

            PR fortran/99171
            * testsuite/libgomp.fortran/dummy-procs-1.f90: New test.

    (cherry picked from commit e9b34037cdd196ab912a7ac3358f8a8d3e307e92)

[Bug fortran/99171] [10/11 Regression] Optional procedure call inside OpenMP parallel loop produces Segmentation Fault

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99171

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org
           Keywords|                            |wrong-code
            Summary|[10/11 Regression] Optional |[10/11 Regression] Optional
                   |procedure call inside Open  |procedure call inside
                   |MP parallel loop produces   |OpenMP parallel loop
                   |Segmentation Fault          |produces Segmentation Fault
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> ---
FIXED – both on mainline (GCC 11) and on the GCC 11 branch.

Thanks for the report!

[Bug fortran/99171] [10/11 Regression] Optional procedure call inside OpenMP parallel loop produces Segmentation Fault

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99171

--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to Tobias Burnus from comment #4)
> FIXED – both on mainline (GCC 11) and on the GCC 11 branch.

... and GCC 10 (!) branch.