isl_basic_set_opt: avoid invalid access on error path

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

diff --git a/isl_morph.c b/isl_morph.c
index 230f14e..9fc39d2 100644 (file)
--- a/isl_morph.c
+++ b/isl_morph.c
@@ -1,7 +1,7 @@
 /*
  * Copyright 2010      INRIA Saclay
  *
- * 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, INRIA Saclay - Ile-de-France,
  * Parc Club Orsay Universite, ZAC des vignes, 4 rue Jacques Monod,
@@ -473,6 +473,10 @@ error:
  * We basically just call isl_mat_parameter_compression with the right input
  * and then extend the resulting matrix to include the variables.
  *
+ * The implementation assumes that "bset" does not have any equalities
+ * that only involve the parameters and that isl_basic_set_gauss has
+ * been applied to "bset".
+ *
  * Let the equalities be given as
  *
  *     B(p) + A x = 0
@@ -509,7 +513,14 @@ __isl_give isl_morph *isl_basic_set_parameter_compression(
        nparam = isl_basic_set_dim(bset, isl_dim_param);
        nvar = isl_basic_set_dim(bset, isl_dim_set);
 
-       isl_assert(bset->ctx, n_eq <= nvar, return NULL);
+       if (isl_seq_first_non_zero(bset->eq[bset->n_eq - 1] + 1 + nparam,
+                                   nvar) == -1)
+               isl_die(isl_basic_set_get_ctx(bset), isl_error_invalid,
+                       "input not allowed to have parameter equalities",
+                       return NULL);
+       if (n_eq > nvar)
+               isl_die(isl_basic_set_get_ctx(bset), isl_error_invalid,
+                       "input not gaussed", return NULL);
 
        d = isl_vec_alloc(bset->ctx, n_eq);
        B = isl_mat_sub_alloc6(bset->ctx, bset->eq, 0, n_eq, 0, 1 + nparam);