This fixes an ice-on-invalid for fortran.
Bootstrapped/tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2016-09-22 Richard Biener <rguent...@suse.de>
PR middle-end/77678
* expr.c (expand_expr_real_1): Guard array access against negative
offset.
Index: gcc/expr.c
===================================================================
--- gcc/expr.c (revision 240342)
+++ gcc/expr.c (working copy)
@@ -10274,7 +10257,8 @@ expand_expr_real_1 (tree exp, rtx target
fold_convert_loc (loc, sizetype,
low_bound));
- if (compare_tree_int (index1, TREE_STRING_LENGTH (init)) < 0)
+ if (tree_fits_uhwi_p (index1)
+ && compare_tree_int (index1, TREE_STRING_LENGTH (init)) < 0)
{
tree type = TREE_TYPE (TREE_TYPE (init));
machine_mode mode = TYPE_MODE (type);
