driver: factor out a helper and make another helper public

src/librustc_driver/lib.rs

@@ -518,7 +518,7 @@ fn build_controller(&mut self,
                         -> CompileController<'a> {
         let mut control = CompileController::basic();
 
-        control.keep_ast = sess.opts.debugging_opts.keep_ast || save_analysis(sess);
+        control.keep_ast = sess.opts.debugging_opts.keep_ast;
 
         if let Some((ppm, opt_uii)) = parse_pretty(sess, matches) {
             if ppm.needs_ast_map(&opt_uii) {
@@ -574,19 +574,7 @@ fn build_controller(&mut self,
         }
 
         if save_analysis(sess) {
-            control.after_analysis.callback = box |state| {
-                time(state.session.time_passes(), "save analysis", || {
-                    save::process_crate(state.tcx.unwrap(),
-                                        state.expanded_crate.unwrap(),
-                                        state.analysis.unwrap(),
-                                        state.crate_name.unwrap(),
-                                        None,
-                                        DumpHandler::new(state.out_dir,
-                                                         state.crate_name.unwrap()))
-                });
-            };
-            control.after_analysis.run_callback_on_error = true;
-            control.make_glob_map = resolve::MakeGlobMap::Yes;
+            enable_save_analysis(&mut control);
         }
 
         if sess.print_fuel_crate.is_some() {
@@ -603,6 +591,23 @@ fn build_controller(&mut self,
     }
 }
 
+pub fn enable_save_analysis(control: &mut CompileController) {
+    control.keep_ast = true;
+    control.after_analysis.callback = box |state| {
+        time(state.session.time_passes(), "save analysis", || {
+            save::process_crate(state.tcx.unwrap(),
+                                state.expanded_crate.unwrap(),
+                                state.analysis.unwrap(),
+                                state.crate_name.unwrap(),
+                                None,
+                                DumpHandler::new(state.out_dir,
+                                                 state.crate_name.unwrap()))
+        });
+    };
+    control.after_analysis.run_callback_on_error = true;
+    control.make_glob_map = resolve::MakeGlobMap::Yes;
+}
+
 fn save_analysis(sess: &Session) -> bool {
     sess.opts.debugging_opts.save_analysis
 }
@@ -1215,7 +1220,7 @@ pub fn diagnostics_registry() -> errors::registry::Registry {
     Registry::new(&all_errors)
 }
 
-fn get_args() -> Vec<String> {
+pub fn get_args() -> Vec<String> {
     env::args_os().enumerate()
         .map(|(i, arg)| arg.into_string().unwrap_or_else(|arg| {
              early_error(ErrorOutputType::default(),