[Bug fortran/62309] New: -fno-automatic with -finit-local prevents initialization of automatics in recursive functions

[fritzoreese at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62309

            Bug ID: 62309
           Summary: -fno-automatic with -finit-local prevents
                    initialization of automatics in recursive functions
           Product: gcc
           Version: 4.8.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fritzoreese at gmail dot com

It seems with gcc-4.8.3 -fno-automatic prevents initializers from being applied
to automatic variables. The following does not behave as I would expect it to
with (linux-x86-64):

      function f (x)
        implicit none
        integer f, x
        integer a ! should be SAVEd from -fno-automatic
        a = a + x ! should increment by y every time
        f = a
        return
      endfunction

      recursive function g (x)
        implicit none
        integer g, x
        integer b ! should be automatic from recursive
        b = b + x ! should be set to y every time
        g = b
        return
      endfunction

      implicit none
      integer f, g

      ! Should return static value of a; accumulates x
      print *, f(3) ! -> 3, ok
      print *, f(4) ! -> 7, ok
      print *, f(2) ! -> 2, ok

      ! Should return automatic value of c; equal to y each time
      print *, g(3) ! -> garbage, expected 3
      print *, g(4) ! -> garbage, expected 4
      print *, g(2) ! -> garbage, expected 2

      end
$ gfortran -fno-automatic -finit-local-zero auto_test.f
$ ./a.out
           3
           7
           9
       32770
       32771
       32769
$

According to gfortran's manual page, -fno-automatic should "Treat each program
unit (except those marked as RECURSIVE) as if the "SAVE" statement were
specified for every local variable [...]". As far as I can tell,
-finit-local-zero should still initialize automatic variables in RECURSIVE
functions.