[Bug fortran/50514] gfortran should check ISHFT & ISHFTC aruments (r178939)
sgk at troutmask dot apl.washington.edu
gcc-bugzilla@gcc.gnu.org
Wed Sep 28 20:03:00 GMT 2011
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50514
--- Comment #3 from Steve Kargl <sgk at troutmask dot apl.washington.edu> 2011-09-28 19:45:48 UTC ---
On Wed, Sep 28, 2011 at 09:20:40AM +0000, zeccav at gmail dot com wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50514
>
> --- Comment #2 from Vittorio Zecca <zeccav at gmail dot com> 2011-09-28 09:20:40 UTC ---
> I meant checking static expressions at compilation time, as in my example.
> This has no cost at run time.
I know want you meant.
> You proposed a run time check that still should be done if requested with a
> kind of -fcheck option.
I disagree.
> By the way, gfortran is already checking consistency of static arguments to
> intrinsic functions, it is that just these one are left unchecked.
Yes, I know. I wrote some of the code.
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;
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