re PR fortran/60522 (WHERE construct causes an ICE in gfc_trans_where_2)

2014-04-27  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/60522
	* frontend-passes.c (cfe_code):  Do not walk subtrees
	for WHERE.

2014-04-27  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/60522
	* gfortran.dg/where_4.f90:  New test case.

From-SVN: r208883

gcc/fortran/ChangeLog

+2014-04-27  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/60522
+	* frontend-passes.c (cfe_code):  Do not walk subtrees
+	for WHERE.
+
 2014-03-27  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/58880

gcc/fortran/frontend-passes.c

@@ -627,12 +627,35 @@ cfe_expr_0 (gfc_expr **e, int *walk_subtrees,
    to insert statements as needed.  */
 
 static int
-cfe_code (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED,
-	  void *data ATTRIBUTE_UNUSED)
+cfe_code (gfc_code **c, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
 {
   current_code = c;
   inserted_block = NULL;
   changed_statement = NULL;
+
+  /* Do not do anything inside a WHERE statement; scalar assignments, BLOCKs
+     and allocation on assigment are prohibited inside WHERE, and finally
+     masking an expression would lead to wrong-code when replacing
+
+     WHERE (a>0)
+       b = sum(foo(a) + foo(a))
+     END WHERE
+
+     with
+
+     WHERE (a > 0)
+       tmp = foo(a)
+       b = sum(tmp + tmp)
+     END WHERE
+*/
+
+  if ((*c)->op == EXEC_WHERE)
+    {
+      *walk_subtrees = 0;
+      return 0;
+    }
+  
+
   return 0;
 }
 

gcc/testsuite/ChangeLog

+2014-04-27  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/60522
+	* gfortran.dg/where_4.f90:  New test case.
+
 2014-03-27  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/58880

gcc/testsuite/gfortran.dg/where_4.f90

+! { dg-do compile }
+! PR 60522 - this used to ICE.
+! Original test case Roger Ferrer Ibanez
+subroutine foo(a, b)
+   implicit none
+   integer, dimension(:), intent(inout) :: a
+   integer, dimension(:), intent(in) :: b
+
+   where (b(:) > 0)
+      where (b(:) > 100)
+         a(lbound(a, 1):ubound(a, 1)) = b(lbound(b, 1):ubound(b, 1)) * b(lbound(b, 1):ubound(b, 1)) - 100
+      elsewhere
+         a(lbound(a, 1):ubound(a, 1)) = b(lbound(b, 1):ubound(b, 1)) * b(lbound(b, 1):ubound(b, 1))
+      end where
+   elsewhere
+      a(lbound(a, 1):ubound(a, 1)) = - b(lbound(b, 1):ubound(b, 1)) * b(lbound(b, 1):ubound(b, 1))
+   end where
+end subroutine foo