[PATCH] fortran/50514 -- Fix static chekcing of ISHFT[C] arguments.

[Tobias Burnus]

On 10/15/2011 11:21 PM, Steve Kargl wrote:
> OK for trunk?
>
> 2011-10-15  Steven G. Kargl<kargl@gcc.gnu.org>
>
> 	* gfortran.dg/ishft_3.f90:  Update test.

I am not so happy with complete test replacements. How about adding it 
as new test case?


> 2011-10-15  Steven G. Kargl<kargl@gcc.gnu.org>
>
> 	* check.c (less_than_bitsize1): Check|shift|  <= bit_size(i).
> 	(gfc_check_ishftc):  Check|shift|  <= bit_size(i) and check
> 	that size is positive.

I somehow find less_than_bitsize1's

+      if (strncmp (arg2, "ISHFT", 5) == 0)

not that elegant and would prefer another argument, which tells the 
function that it should take the absolute value of the argument; 
however, given that ISHFT seems to be the only function which allows 
negative arguments, one could also leave it.

OK with considering the two remarks. Thanks for the patch!

Tobias

PS: As you have probably seen, I found a related issue regarding 
DSHIFTL/DSHIFTR: PR 50753.

> Index: testsuite/gfortran.dg/ishft_3.f90
> ===================================================================
> --- testsuite/gfortran.dg/ishft_3.f90	(revision 179208)
> +++ testsuite/gfortran.dg/ishft_3.f90	(working copy)
> @@ -1,11 +1,38 @@
>   ! { dg-do compile }
> +! PR fortran/50514
>   program ishft_3
> -  integer i, j
> -  write(*,*) ishftc( 3, 2, 3 )
> -  write(*,*) ishftc( 3, 2, i )
> -  write(*,*) ishftc( 3, i, j )
> -  write(*,*) ishftc( 3, 128 )     ! { dg-error "exceeds BIT_SIZE of first" }
> -  write(*,*) ishftc( 3, 0, 128 )  ! { dg-error "exceeds BIT_SIZE of first" }
> -  write(*,*) ishftc( 3, 0, 0 )    ! { dg-error "Invalid third argument" }
> -  write(*,*) ishftc( 3, 3, 2 )    ! { dg-error "exceeds third argument" }
> +
> +   implicit none
> +
> +   integer j, m
> +
> +   m = 42
> +   !
> +   ! These should compile.
> +   !
> +   j = ishft(m, 16)
> +   j = ishft(m, -16)
> +   j = ishftc(m, 16)
> +   j = ishftc(m, -16)
> +   !
> +   ! These should issue an error.
> +   !
> +   j = ishft(m, 640)    ! { dg-error "absolute value of SHIFT" }
> +   j = ishftc(m, 640)   ! { dg-error "absolute value of SHIFT" }
> +   j = ishft(m, -640)   ! { dg-error "absolute value of SHIFT" }
> +   j = ishftc(m, -640)  ! { dg-error "absolute value of SHIFT" }
> +
> +   ! abs(SHIFT) must be<= SIZE
> +
> +   j = ishftc(m,  1, 2)
> +   j = ishftc(m,  1, 2)
> +   j = ishftc(m, -1, 2)
> +   j = ishftc(m, -1, 2)
> +
> +   j = ishftc(m,  10, 2)! { dg-error "absolute value of SHIFT" }
> +   j = ishftc(m,  10, 2)! { dg-error "absolute value of SHIFT" }
> +   j = ishftc(m, -10, 2)! { dg-error "absolute value of SHIFT" }
> +   j = ishftc(m, -10, 2)! { dg-error "absolute value of SHIFT" }
> +
> +   j = ishftc(m, 1, -2) ! { dg-error "must be positive" }
>   end program
>
> Index: fortran/check.c
> ===================================================================
> --- fortran/check.c	(revision 179208)
> +++ fortran/check.c	(working copy)
> @@ -318,6 +318,22 @@ less_than_bitsize1 (const char *arg1, gf
>       {
>         gfc_extract_int (expr2,&i2);
>         i3 = gfc_validate_kind (BT_INTEGER, expr1->ts.kind, false);
> +
> +      /* For ISHFT[C],|shift|  <= bit_size(i).  */
> +      if (strncmp (arg2, "ISHFT", 5) == 0)
> +	{
> +	  if (i2<  0)
> +	    i2 = -i2;
> +
> +	  if (i2>  gfc_integer_kinds[i3].bit_size)
> +	    {
> +	      gfc_error ("The absolute value of SHIFT at %L must be less "
> +			 "than or equal to BIT_SIZE('%s')",
> +			&expr2->where, arg1);
> +	      return FAILURE;
> +	    }
> +	}
> +
>         if (or_equal)
>   	{
>   	  if (i2>  gfc_integer_kinds[i3].bit_size)
> @@ -1961,6 +1977,9 @@ gfc_check_ishft (gfc_expr *i, gfc_expr *
>         || type_check (shift, 1, BT_INTEGER) == FAILURE)
>       return FAILURE;
>
> +  if (less_than_bitsize1 ("I", i, "ISHFT", shift, true) == FAILURE)
> +    return FAILURE;
> +
>     return SUCCESS;
>   }
>
> @@ -1972,7 +1991,35 @@ gfc_check_ishftc (gfc_expr *i, gfc_expr
>         || type_check (shift, 1, BT_INTEGER) == FAILURE)
>       return FAILURE;
>
> -  if (size != NULL&&  type_check (size, 2, BT_INTEGER) == FAILURE)
> +  if (size != NULL)
> +    {
> +      int i2, i3;
> +
> +      if (type_check (size, 2, BT_INTEGER) == FAILURE)
> +	return FAILURE;
> +
> +      if (less_than_bitsize1 ("I", i, "SIZE", size, true) == FAILURE)
> +	return FAILURE;
> +
> +      gfc_extract_int (size,&i3);
> +      if (i3<= 0)
> +	{
> +	  gfc_error ("SIZE at %L must be positive",&size->where);
> +	  return FAILURE;
> +	}
> +
> +      gfc_extract_int (shift,&i2);
> +      if (i2<  0)
> +	i2 = -i2;
> +
> +      if (i2>  i3)
> +	{
> +	  gfc_error ("The absolute value of SHIFT at %L must be less than "
> +		     "or equal to SIZE at %L",&shift->where,&size->where);
> +	  return FAILURE;
> +	}
> +    }
> +  else if (less_than_bitsize1 ("I", i, "ISHFTC", shift, true) == FAILURE)
>       return FAILURE;
>
>     return SUCCESS;