re PR fortran/50130 (ICE with invalid array slice)

2011-08-21  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/50130
	* resolve.c (resolve_array_ref):  Don't calculate upper bound
	if the stride is zero.

2011-08-21  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/50130
	* gfortran.dg/zero_stride_1.f90:  New test.

From-SVN: r177940

gcc/fortran/ChangeLog

+2011-08-21  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/50130
+	* resolve.c (resolve_array_ref):  Don't calculate upper bound
+	if the stride is zero.
+
 2011-08-20  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/49638

gcc/fortran/resolve.c

@@ -4569,10 +4569,11 @@ resolve_array_ref (gfc_array_ref *ar)
       /* Fill in the upper bound, which may be lower than the
 	 specified one for something like a(2:10:5), which is
 	 identical to a(2:7:5).  Only relevant for strides not equal
-	 to one.  */
+	 to one.  Don't try a division by zero.  */
       if (ar->dimen_type[i] == DIMEN_RANGE
 	  && ar->stride[i] != NULL && ar->stride[i]->expr_type == EXPR_CONSTANT
-	  && mpz_cmp_si (ar->stride[i]->value.integer, 1L) != 0)
+	  && mpz_cmp_si (ar->stride[i]->value.integer, 1L) != 0
+	  && mpz_cmp_si (ar->stride[i]->value.integer, 0L) != 0)
 	{
 	  mpz_t size, end;
 

gcc/testsuite/ChangeLog

+2011-08-21  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/50130
+	* gfortran.dg/zero_stride_1.f90:  New test.
+
 2011-08-20  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/49638

gcc/testsuite/gfortran.dg/zero_stride_1.f90

+! { dg-do compile }
+!  PR 50130 - this caused an ICE.  Test case supplied by Joost
+!  VandeVondele.
+integer, parameter :: a(10)=0
+integer, parameter :: b(10)=a(1:10:0) ! { dg-error "Illegal stride of zero" }
+END
+