[Bug fortran/66545] New: ICE on using undefined parameter/variable values

["gerhard dot steinmetz dot fortran at t-online dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66545

            Bug ID: 66545
           Summary: ICE on using undefined parameter/variable values
           Product: gcc
           Version: 5.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gerhard.steinmetz.fortran@t-online.de
  Target Milestone: ---

This code uses parameter/variable values before they are defined/initialized.

$ cat z1_complex.f90
   program p
      complex, parameter :: c1 = (c1)
      complex, parameter :: c2 = c2
      complex :: c3 = (c3)
      complex :: c4 = c4
      complex :: c5
      complex :: c6
      c5 = (c5)
      c6 = c6
   end


For example, compiling with :

$ gfortran -g -O0 -Wall -fcheck=all -fno-frontend-optimize \
                  -Wuninitialized -fsanitize=undefined \
                  -c z1_complex.f90


yields (with gfortran 5.1.1 on SUSE Linux 13.2, 64 bit) :
f951: internal compiler error: Segmentation fault