range: Eliminate direct Range member access

Users of struct Range mess liberally with its members, which makes
refactoring hard.  Create a set of methods, and convert all users to
call them instead of accessing members.  The methods have carefully
worded contracts, and use assertions to check them.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/util/log.c b/util/log.c
index f811d61..4da635c 100644
--- a/util/log.c
+++ b/util/log.c
@@ -132,7 +132,7 @@
         int i = 0;
         for (i = 0; i < debug_regions->len; i++) {
             Range *range = &g_array_index(debug_regions, Range, i);
-            if (addr >= range->begin && addr <= range->end - 1) {
+            if (range_contains(range, addr)) {
                 return true;
             }
         }
@@ -208,8 +208,7 @@
             error_setg(errp, "Invalid range");
             goto out;
         }
-        range.begin = lob;
-        range.end = upb + 1;
+        range_set_bounds(&range, lob, upb);
         g_array_append_val(debug_regions, range);
     }
 out:
diff --git a/util/range.c b/util/range.c
index e90c988..e5f2e71 100644
--- a/util/range.c
+++ b/util/range.c
@@ -46,8 +46,7 @@
 {
     GList *l;
 
-    /* Range lists require no empty ranges */
-    assert(data->begin < data->end || (data->begin && !data->end));
+    assert(!range_is_empty(data));
 
     /* Skip all list elements strictly less than data */
     for (l = list; l && range_compare(l->data, data) < 0; l = l->next) {