Segmentation error on calling subroutine for the second time on pgf90 compiler on linux

Question

I can not call the same subroutine two time using pgf90 fortran complier on Linux environment. To call the subroutine for the 1st time is OK but calling it for the 2nd time, it gives Segmentation fault. Can some one give some suggestion, what is wrong with my code, As simple example is given as

P.S. with gfortran it is OK, even i tried it on the intel visual fortran and it is OK

program main 

use module_Append_1DI

implicit none 

integer, allocatable:: Arr(:)

integer::Brr(2)

Brr=[3, 4]

call Append_1DI(Arr,Brr)

write(*,*)Arr

call Append_1DI(Arr,Brr)

write(*,*)Arr

end program main 

---

module module_Append_1DI

contains

subroutine Append_1DI(A,B)

implicit none 

!================================================

integer, allocatable, intent(inout)::A(:)

integer, intent(in)::B(:)

integer, allocatable::temp(:)

integer::sizeA,sizeB,sizeN

!================================================

sizeA=size(A); sizeB=size(B); sizeN=sizeA+sizeB

allocate(temp(sizeN)); temp(1:sizeA)=A

call move_alloc(from=temp,to=A)

A(sizeA+1:sizeN)=B

end subroutine Append_1DI

end module module_Append_1DI

Answer 1

To be honest I'm amazed it works the first time you call it. That's because A is not then allocated, and you are not allowed to use the size intrinsic on an unallocated allocatable array. In fact if you turn on all the checking flags ifort tells you this

Wot now? ifort --version
ifort (IFORT) 12.0.4 20110427
Copyright (C) 1985-2011 Intel Corporation.  All rights reserved.

Wot now? ifort -check all -g -traceback s.f90
Wot now? ./a.out
forrtl: severe (408): fort: (8): Attempt to fetch from allocatable variable A when it is not allocated

Image              PC                Routine            Line        Source             
a.out              000000000046A3FA  Unknown               Unknown  Unknown
a.out              0000000000468F75  Unknown               Unknown  Unknown
a.out              0000000000420B56  Unknown               Unknown  Unknown
a.out              0000000000404C95  Unknown               Unknown  Unknown
a.out              00000000004050E9  Unknown               Unknown  Unknown
a.out              0000000000402ED5  module_append_1di          24  s.f90
a.out              000000000040385F  MAIN__                     46  s.f90
a.out              0000000000402B2C  Unknown               Unknown  Unknown
libc.so.6          00007FB5F826DEFF  Unknown               Unknown  Unknown
a.out              0000000000402A29  Unknown               Unknown  Unknown

gfortran is less clear, but still tells you something is wrong

Wot now? gfortran --version
GNU Fortran (Ubuntu/Linaro 4.5.2-8ubuntu4) 4.5.2
Copyright (C) 2010 Free Software Foundation, Inc.

GNU Fortran comes with NO WARRANTY, to the extent permitted by law.
You may redistribute copies of GNU Fortran
under the terms of the GNU General Public License.
For more information about these matters, see the file named COPYING

Wot now? gfortran -Wall -Wextra -pedantic -fbounds-check -std=f2003 -g -fbacktrace s.f90
Wot now? ./a.out
At line 24 of file s.f90
Fortran runtime error: Array bound mismatch for dimension 1 of array 'temp' (1252015568/139957056323024)

Backtrace for this error:
  + function append_1di (0x400EC7)
    at line 24 of file s.f90
  + in the main program
    at line 48 of file s.f90
  + /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xff) [0x7f4a4a1deeff]

And to pick another random compiler, that from Sun/oracle, again you get the same message

Wot now? f90 -V
f90: Sun Fortran 95 8.5 Linux_i386 2010/08/13
usage: f90 [ options ] files.  Use 'f90 -flags' for details
Wot now? f90 -C s.f90
Wot now? ./a.out

 ******  FORTRAN RUN-TIME SYSTEM  ******
 Attempting to use an unallocated ALLOCATABLE 'A'
 Location:  line 22 column 16 of 's.f90'
Aborted

So the problem is the use of A before it is allocated.

Is the confusion that you think this is a zero size array? Well you need to get that out of your head - an unallocated alloctable array has no defined size at all, which is very different from allocated bu zero size array.

Ian