trans: save metadata even with -Z no-trans.

src/librustc/session/config.rs

@@ -1103,7 +1103,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
     let no_analysis = debugging_opts.no_analysis;
 
     let mut output_types = HashMap::new();
-    if !debugging_opts.parse_only && !no_trans {
+    if !debugging_opts.parse_only {
         for list in matches.opt_strs("emit") {
             for output_type in list.split(',') {
                 let mut parts = output_type.splitn(2, '=');

src/librustc_driver/lib.rs

@@ -504,10 +504,6 @@ impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
             control.after_write_deps.stop = Compilation::Stop;
         }
 
-        if sess.opts.no_trans {
-            control.after_analysis.stop = Compilation::Stop;
-        }
-
         if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe) {
             control.after_llvm.stop = Compilation::Stop;
         }

src/librustc_trans/base.rs

@@ -2424,11 +2424,7 @@ fn contains_null(s: &str) -> bool {
     s.bytes().any(|b| b == 0)
 }
 
-pub fn write_metadata<'a, 'tcx>(cx: &SharedCrateContext<'a, 'tcx>,
-                                krate: &hir::Crate,
-                                reachable: &NodeSet,
-                                mir_map: &MirMap<'tcx>)
-                                -> Vec<u8> {
+pub fn write_metadata<'a, 'tcx>(cx: &SharedCrateContext<'a, 'tcx>) -> Vec<u8> {
     use flate;
 
     let any_library = cx.sess()
@@ -2444,9 +2440,9 @@ pub fn write_metadata<'a, 'tcx>(cx: &SharedCrateContext<'a, 'tcx>,
     let metadata = cstore.encode_metadata(cx.tcx(),
                                           cx.export_map(),
                                           cx.link_meta(),
-                                          reachable,
-                                          mir_map,
-                                          krate);
+                                          cx.reachable(),
+                                          cx.mir_map(),
+                                          cx.tcx().map.krate());
     let mut compressed = cstore.metadata_encoding_version().to_vec();
     compressed.extend_from_slice(&flate::deflate_bytes(&metadata));
 
@@ -2679,6 +2675,16 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                              reachable,
                                              check_overflow,
                                              check_dropflag);
+    // Translate the metadata.
+    let metadata = time(tcx.sess.time_passes(), "write metadata", || {
+        write_metadata(&shared_ccx)
+    });
+
+    let metadata_module = ModuleTranslation {
+        llcx: shared_ccx.metadata_llcx(),
+        llmod: shared_ccx.metadata_llmod(),
+    };
+    let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
 
     let codegen_units = collect_and_partition_translation_items(&shared_ccx);
     let codegen_unit_count = codegen_units.len();
@@ -2687,6 +2693,24 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
     let crate_context_list = CrateContextList::new(&shared_ccx, codegen_units);
 
+    let modules = crate_context_list.iter()
+        .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
+        .collect();
+
+    // Skip crate items and just output metadata in -Z no-trans mode.
+    if tcx.sess.opts.no_trans {
+        let linker_info = LinkerInfo::new(&shared_ccx, &[]);
+        return CrateTranslation {
+            modules: modules,
+            metadata_module: metadata_module,
+            link: link_meta,
+            metadata: metadata,
+            reachable: vec![],
+            no_builtins: no_builtins,
+            linker_info: linker_info
+        };
+    }
+
     {
         let ccx = crate_context_list.get_ccx(0);
 
@@ -2718,10 +2742,6 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
     let reachable_symbol_ids = filter_reachable_ids(&shared_ccx);
 
-    // Translate the metadata.
-    let metadata = time(tcx.sess.time_passes(), "write metadata", || {
-        write_metadata(&shared_ccx, krate, &reachable_symbol_ids, mir_map)
-    });
 
     if shared_ccx.sess().trans_stats() {
         let stats = shared_ccx.stats();
@@ -2752,10 +2772,6 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         }
     }
 
-    let modules = crate_context_list.iter()
-        .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
-        .collect();
-
     let sess = shared_ccx.sess();
     let mut reachable_symbols = reachable_symbol_ids.iter().map(|&id| {
         let def_id = shared_ccx.tcx().map.local_def_id(id);
@@ -2789,12 +2805,6 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         create_imps(&crate_context_list);
     }
 
-    let metadata_module = ModuleTranslation {
-        llcx: shared_ccx.metadata_llcx(),
-        llmod: shared_ccx.metadata_llmod(),
-    };
-    let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
-
     let linker_info = LinkerInfo::new(&shared_ccx, &reachable_symbols);
     CrateTranslation {
         modules: modules,

src/librustc_trans/context.rs

@@ -485,6 +485,10 @@ impl<'b, 'tcx> SharedCrateContext<'b, 'tcx> {
     pub fn symbol_hasher(&self) -> &RefCell<Sha256> {
         &self.symbol_hasher
     }
+
+    pub fn mir_map(&self) -> &MirMap<'tcx> {
+        &self.mir_map
+    }
 }
 
 impl<'tcx> LocalCrateContext<'tcx> {