https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119118
--- Comment #5 from anlauf at gcc dot gnu.org --- (In reply to anlauf from comment #3) > diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc > index fbe7333fd71..ed29623fcdf 100644 > --- a/gcc/fortran/trans-expr.cc > +++ b/gcc/fortran/trans-expr.cc > @@ -2814,8 +2813,8 @@ gfc_conv_substring (gfc_se * se, gfc_ref * ref, int > kind, > end.expr = gfc_evaluate_now (end.expr, &se->pre); > > if ((gfc_option.rtcheck & GFC_RTCHECK_BOUNDS) > - && (ref->u.ss.start->symtree > - && !ref->u.ss.start->symtree->n.sym->attr.implied_index)) > + && !(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, This fix attempt reveals another problem. Changing in testcase gcc/testsuite/gfortran.dg/bounds_check_23.f90 the line c = [ ( text(i:i), i = 1, len(text) ) ] to c = [ ( text(i+0:i), i = 1, len(text) ) ] which now crashes, as the bounds-checking code is evaluated outside the constructor.