Fortran - out of bounds in array constructor with implied do loop

gcc/fortran/ChangeLog:

	PR fortran/98490
	* trans-expr.c (gfc_conv_substring): Do not generate substring
	bounds check for implied do loop index variable before it actually
	becomes defined.

gcc/testsuite/ChangeLog:

	PR fortran/98490
	* gfortran.dg/bounds_check_23.f90: New test.

diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index c4291cc..18d6651 100644 (file)
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -2630,7 +2630,9 @@ gfc_conv_substring (gfc_se * se, gfc_ref * ref, int kind,
   if (!CONSTANT_CLASS_P (tmp) && !DECL_P (tmp))
     end.expr = gfc_evaluate_now (end.expr, &se->pre);
 
-  if (gfc_option.rtcheck & GFC_RTCHECK_BOUNDS)
+  if ((gfc_option.rtcheck & GFC_RTCHECK_BOUNDS)
+      && (ref->u.ss.start->symtree
+         && !ref->u.ss.start->symtree->n.sym->attr.implied_index))
     {
       tree nonempty = fold_build2_loc (input_location, LE_EXPR,
                                       logical_type_node, start.expr,

diff --git a/gcc/testsuite/gfortran.dg/bounds_check_23.f90 b/gcc/testsuite/gfortran.dg/bounds_check_23.f90
new file mode 100644 (file)
index 0000000..8de90c7
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bounds_check_23.f90
@@ -0,0 +1,18 @@
+! { dg-do run }
+! { dg-options "-fcheck=bounds -fdump-tree-original" }
+! PR fortran/98490 - out of bounds in array constructor with implied do loop
+
+program test
+  implicit none
+  call sub('Lorem ipsum')
+contains
+  subroutine sub( text )
+    character(len=*), intent(in)  :: text
+    character(len=1), allocatable :: c(:)
+    integer :: i
+    c = [ ( text(i:i), i = 1, len(text) ) ]
+    if (c(1) /= 'L') stop 1
+  end subroutine sub
+end program test
+
+! { dg-final { scan-tree-dump-times "Substring out of bounds:" 2 "original" } }