isl_reordering_extend_dim: don't mess with copies of input

In particular, perform an isl_reordering_cow before changing anythin.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/isl_reordering.c b/isl_reordering.c
index 6a5b014..f19bcd6 100644 (file)
--- a/isl_reordering.c
+++ b/isl_reordering.c
@@ -37,16 +37,49 @@ __isl_give isl_reordering *isl_reordering_copy(__isl_keep isl_reordering *exp)
        return exp;
 }
 
-void isl_reordering_free(__isl_take isl_reordering *exp)
+__isl_give isl_reordering *isl_reordering_dup(__isl_keep isl_reordering *r)
+{
+       int i;
+       isl_reordering *dup;
+
+       if (!r)
+               return NULL;
+
+       dup = isl_reordering_alloc(r->dim->ctx, r->len);
+       if (!dup)
+               return NULL;
+
+       dup->dim = isl_dim_copy(r->dim);
+       if (!dup->dim)
+               return isl_reordering_free(dup);
+       for (i = 0; i < dup->len; ++i)
+               dup->pos[i] = r->pos[i];
+
+       return dup;
+}
+
+__isl_give isl_reordering *isl_reordering_cow(__isl_take isl_reordering *r)
+{
+       if (!r)
+               return NULL;
+
+       if (r->ref == 1)
+               return r;
+       r->ref--;
+       return isl_reordering_dup(r);
+}
+
+void *isl_reordering_free(__isl_take isl_reordering *exp)
 {
        if (!exp)
-               return;
+               return NULL;
 
        if (--exp->ref > 0)
-               return;
+               return NULL;
 
        isl_dim_free(exp->dim);
        free(exp);
+       return NULL;
 }
 
 /* Construct a reordering that maps the parameters of "alignee"
@@ -141,6 +174,7 @@ __isl_give isl_reordering *isl_reordering_extend_dim(
 
        res = isl_reordering_extend(isl_reordering_copy(exp),
                                            isl_dim_total(dim) - exp->len);
+       res = isl_reordering_cow(res);
        if (!res)
                goto error;
        isl_dim_free(res->dim);

diff --git a/isl_reordering.h b/isl_reordering.h
index cfec95a..7560d3a 100644 (file)
--- a/isl_reordering.h
+++ b/isl_reordering.h
@@ -22,7 +22,7 @@ typedef struct isl_reordering isl_reordering;
 __isl_give isl_reordering *isl_parameter_alignment_reordering(
        __isl_keep isl_dim *alignee, __isl_keep isl_dim *aligner);
 __isl_give isl_reordering *isl_reordering_copy(__isl_keep isl_reordering *exp);
-void isl_reordering_free(__isl_take isl_reordering *exp);
+void *isl_reordering_free(__isl_take isl_reordering *exp);
 __isl_give isl_reordering *isl_reordering_extend_dim(
        __isl_take isl_reordering *exp, __isl_take isl_dim *dim);
 __isl_give isl_reordering *isl_reordering_extend(__isl_take isl_reordering *exp,