isl_basic_set_expand_divs: avoid invalid access on error

[platform/upstream/isl.git] / isl_tab.c

diff --git a/isl_tab.c b/isl_tab.c
index 097b335..3fc0367 100644 (file)
--- a/isl_tab.c
+++ b/isl_tab.c
@@ -1,7 +1,7 @@
 /*
  * Copyright 2008-2009 Katholieke Universiteit Leuven
  *
- * Use of this software is governed by the GNU LGPLv2.1 license
+ * Use of this software is governed by the MIT license
  *
  * Written by Sven Verdoolaege, K.U.Leuven, Departement
  * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
@@ -787,6 +787,8 @@ static int push_union(struct isl_tab *tab,
 {
        struct isl_tab_undo *undo;
 
+       if (!tab)
+               return -1;
        if (!tab->need_undo)
                return 0;
 
@@ -2556,6 +2558,13 @@ struct isl_tab *isl_tab_relax(struct isl_tab *tab, int con)
 
        var = &tab->con[con];
 
+       if (var->is_row && (var->index < 0 || var->index < tab->n_redundant))
+               isl_die(tab->mat->ctx, isl_error_invalid,
+                       "cannot relax redundant constraint", goto error);
+       if (!var->is_row && (var->index < 0 || var->index < tab->n_dead))
+               isl_die(tab->mat->ctx, isl_error_invalid,
+                       "cannot relax dead constraint", goto error);
+
        if (!var->is_row && !max_is_manifestly_unbounded(tab, var))
                if (to_row(tab, var, 1) < 0)
                        goto error;