[PATCH] Fix PR fortran/19926

[Steve Kargl]

The attached patch fixes PR fortran/19926.  The problem
is easiest to explain by looking at the snippet of code
from the PR.

subroutine string_comp(i)
   integer, parameter :: map(0:50) = 3
   integer :: i
   i = map(42)
end subroutine string_comp

The problem lies in primary.c:gfc_match_rvalue() where we are
parsing/resolving a PARAMETER expression.  The above parameter
sets sym->value->expr_type = EXPR_CONSTANT, so a branch of an
if statement that test (sym->value->expr_type != EXPR_ARRAY)
because expr_type cannot simultaneous be EXPR_CONSTANT and
EXPR_ARRAY.  To get to the else portion of the test we
can check if sym->as is non-NULL, which indicates that we have
an array with constant content.

Hopefully, the above makes sense, and the patch does the
right thing.

Bootstrapped and regression tested on i386-*-freebsd.
There are no new regressions with this patch.

Erik found the location of bug and provided the initial
patch.  I've changed the patch to the current stated.

2005-06-12  Erik Edelman  <eedelman@acclab.helsinki.fi>
            Steven G. Kargl <kargls@comast.net>

    PR fortran/19926
	* primary.c (gfc_match_rvalue):  expr_type can be EXPR_CONSTANT
	for an array; check that sym->as is NULL.

-- 
Steve
-------------- next part --------------
Index: primary.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fortran/primary.c,v
retrieving revision 1.25
diff -c -p -r1.25 primary.c
*** primary.c	25 Apr 2005 00:08:59 -0000	1.25
--- primary.c	13 Jun 2005 01:28:30 -0000
*************** gfc_match_rvalue (gfc_expr ** result)
*** 1802,1809 ****
        break;
  
      case FL_PARAMETER:
!       if (sym->value
! 	  && sym->value->expr_type != EXPR_ARRAY)
  	e = gfc_copy_expr (sym->value);
        else
  	{
--- 1802,1812 ----
        break;
  
      case FL_PARAMETER:
!       /* A statement of the form "REAL, parameter :: a(0:10) = 1" will
! 	 end up here.  Unfortunately, sym->value->expr_type is set to 
! 	 EXPR_CONSTANT, and so the if () branch would be followed without
! 	 the !sym->as check.  */
!       if (sym->value && sym->value->expr_type != EXPR_ARRAY && !sym->as)
  	e = gfc_copy_expr (sym->value);
        else
  	{
-------------- next part --------------
! { dg-do run }
module b
  type cat
     integer :: i = 0
  end type cat
end module b

program a
  use b
  type(cat) z
  integer :: i = 0, j(4,3,2) = 0
  call string_comp(i)
  if (i /= 3) call abort
  call string_comp(z%i)
  if (z%i /= 3) call abort
  call string_comp(j(1,2,1))
  if (j(1,2,1) /= 3) call abort
end program a

subroutine string_comp(i)
   integer, parameter :: map(0:50) = 3
   integer :: i
   i = map(42)
end subroutine string_comp