[Bug fortran/70953] New: Reallocation on assignment does not work with debug flags

[mrestelli at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70953

            Bug ID: 70953
           Summary: Reallocation on assignment does not work with debug
                    flags
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mrestelli at gmail dot com
  Target Milestone: ---

The attached code produces a runtime error when compiled with some
debug flags (see later). The code however is correct: the dimension
mismatch reported by the compiler is not an error but should trigger
the allocation of the rhs.


program p
 implicit none

 integer, allocatable :: v(:), x(:)

  allocate( x(3) )
  v = int( x ) ! runtime error
  !v =      x   ! works correctly

  write(*,*) shape(v)

end program p



$ gfortran gf.f90 -g -O0 -fcheck=all -ffpe-trap=invalid -o gf
$ ./gf
At line 7 of file gf.f90
Fortran runtime error: Array bound mismatch for dimension 1 of array 'v'
(7233114627794677618/3)


$ gfortran --version
GNU Fortran (GCC) 7.0.0 20160422 (experimental)


Removing either -fcheck=all or -ffe-trap=invalid solves the problem.