Defect: wrong value for this_image() in array constructor

[reinh-bader]

• [x] I am reporting a bug others will be able to reproduce and not asking a question or requesting a new feature.

System information including:

• OpenCoarrays Version: 2.7.1
• Fortran Compiler: gfortran 9.2.0
• C compiler used for building lib: gcc 9.2.0
• Installation method: cmake
• All flags & options passed to the installer CC=gcc FC="gfortran -I$MPI_BASE/include/gfortran/9.1.0" cmake /dss/dsshome1/lrz/noarch/src/compilers/gcc/opencoarrays/OpenCoarrays-2.7.1 -DCMAKE_INSTALL_PREFIX=${PWD}
• Output of uname -a: Linux mpp2-login5 4.4.180-94.100-default #1 SMP Tue Jul 9 19:57:20 UTC 2019 (1569ffb) x86_64 x86_64 x86_64 GNU/Linux
• MPI library being used: Intel MPI 2019 update 5
• Machine architecture and number of physical cores: Haswell 28 core
• Version of CMake: 3.10 (self-installed)

To help us debug your issue please explain:

What you were trying to do (and why)

assign to an array constructor:

a = (/ this_image(), 5*this_image() /)

What happened (include command output, screenshots, logs, etc.)

resulting value of a after the statement is [ 0,0 ]

What you expected to happen

resulting value of a after statement is [ 1,5 ] on image 1

Step-by-step reproduction instructions to reproduce the error/bug

Use the following code:

program test_constr
  use, intrinsic :: iso_fortran_env
  implicit none

  real :: a(2), temp

  a = (/ this_image(), 5*this_image() /)
  write(output_unit,*) "first a is: ", a

  sync all
  a =  this_image()
  write(output_unit,*) "second a is: ", a

end program

build it with caf tu.f90 execute with cafrun -n 1 ./a.out

Notes:

• more than 1 image also gives wrong results on the other images.
• building with -fcoarray=single produces the expected result.
• assigning a scalar that is broadcast to the array works as expected.

[zbeekman]

Thanks for reporting this. This smells like a GFortran front-end/IR problem to me. I'll try to investigate and if I confirm that to be the case we should open an issue upstream.