incr.comp.: Only save and load query result cache when -Zincremental-queries is specified.

Author: michaelwoerister

src/librustc_incremental/persist/load.rs

@@ -202,7 +202,8 @@ pub fn load_dep_graph(sess: &Session) -> PreviousDepGraph {
 }
 
 pub fn load_query_result_cache<'sess>(sess: &'sess Session) -> OnDiskCache<'sess> {
-    if sess.opts.incremental.is_none() {
+    if sess.opts.incremental.is_none() ||
+       !sess.opts.debugging_opts.incremental_queries {
         return OnDiskCache::new_empty(sess.codemap());
     }
 

src/librustc_incremental/persist/save.rs

@@ -69,11 +69,13 @@ pub fn save_dep_graph<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                 |e| encode_query_cache(tcx, e));
     });
 
-    time(sess.time_passes(), "persist dep-graph", || {
-        save_in(sess,
-                dep_graph_path(sess),
-                |e| encode_dep_graph(tcx, e));
-    });
+    if tcx.sess.opts.debugging_opts.incremental_queries {
+        time(sess.time_passes(), "persist dep-graph", || {
+            save_in(sess,
+                    dep_graph_path(sess),
+                    |e| encode_dep_graph(tcx, e));
+        });
+    }
 
     dirty_clean::check_dirty_clean_annotations(tcx);
     dirty_clean::check_dirty_clean_metadata(tcx,