rollup merge of #21830: japaric/for-cleanup

Conflicts:
	src/librustc/metadata/filesearch.rs
	src/librustc_back/target/mod.rs
	src/libstd/os.rs
	src/libstd/sys/windows/os.rs
	src/libsyntax/ext/tt/macro_parser.rs
	src/libsyntax/print/pprust.rs
	src/test/compile-fail/issue-2149.rs

src/librustc_driver/driver.rs

@@ -425,7 +425,7 @@ pub fn phase_2_configure_and_expand(sess: &Session,
                 diagnostics::plugin::expand_build_diagnostic_array);
         }
 
-        for registrar in registrars.into_iter() {
+        for registrar in registrars {
             registry.args_hidden = Some(registrar.args);
             (registrar.fun)(&mut registry);
         }
@@ -435,11 +435,11 @@ pub fn phase_2_configure_and_expand(sess: &Session,
 
     {
         let mut ls = sess.lint_store.borrow_mut();
-        for pass in lint_passes.into_iter() {
+        for pass in lint_passes {
             ls.register_pass(Some(sess), true, pass);
         }
 
-        for (name, to) in lint_groups.into_iter() {
+        for (name, to) in lint_groups {
             ls.register_group(Some(sess), true, name, to);
         }
     }
@@ -761,11 +761,11 @@ fn write_out_deps(sess: &Session,
                   id: &str) {
 
     let mut out_filenames = Vec::new();
-    for output_type in sess.opts.output_types.iter() {
+    for output_type in &sess.opts.output_types {
         let file = outputs.path(*output_type);
         match *output_type {
             config::OutputTypeExe => {
-                for output in sess.crate_types.borrow().iter() {
+                for output in &*sess.crate_types.borrow() {
                     let p = link::filename_for_input(sess, *output,
                                                      id, &file);
                     out_filenames.push(p);
@@ -801,7 +801,7 @@ fn write_out_deps(sess: &Session,
                                    .map(|fmap| escape_dep_filename(&fmap.name[]))
                                    .collect();
         let mut file = try!(old_io::File::create(&deps_filename));
-        for path in out_filenames.iter() {
+        for path in &out_filenames {
             try!(write!(&mut file as &mut Writer,
                           "{}: {}\n\n", path.display(), files.connect(" ")));
         }

src/librustc_driver/lib.rs

@@ -374,7 +374,7 @@ Available lint options:
     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 
     let print_lints = |&: lints: Vec<&Lint>| {
-        for lint in lints.into_iter() {
+        for lint in lints {
             let name = lint.name_lower().replace("_", "-");
             println!("    {}  {:7.7}  {}",
                      padded(&name[]), lint.default_level.as_str(), lint.desc);
@@ -401,7 +401,7 @@ Available lint options:
     println!("    {}  {}", padded("----"), "---------");
 
     let print_lint_groups = |&: lints: Vec<(&'static str, Vec<lint::LintId>)>| {
-        for (name, to) in lints.into_iter() {
+        for (name, to) in lints {
             let name = name.chars().map(|x| x.to_lowercase())
                            .collect::<String>().replace("_", "-");
             let desc = to.into_iter().map(|x| x.as_str().replace("_", "-"))
@@ -436,7 +436,7 @@ Available lint options:
 
 fn describe_debug_flags() {
     println!("\nAvailable debug options:\n");
-    for &(name, _, opt_type_desc, desc) in config::DB_OPTIONS.iter() {
+    for &(name, _, opt_type_desc, desc) in config::DB_OPTIONS {
         let (width, extra) = match opt_type_desc {
             Some(..) => (21, "=val"),
             None => (25, "")
@@ -448,7 +448,7 @@ fn describe_debug_flags() {
 
 fn describe_codegen_flags() {
     println!("\nAvailable codegen options:\n");
-    for &(name, _, opt_type_desc, desc) in config::CG_OPTIONS.iter() {
+    for &(name, _, opt_type_desc, desc) in config::CG_OPTIONS {
         let (width, extra) = match opt_type_desc {
             Some(..) => (21, "=val"),
             None => (25, "")
@@ -543,7 +543,7 @@ fn print_crate_info(sess: &Session,
     if sess.opts.prints.len() == 0 { return false }
 
     let attrs = input.map(|input| parse_crate_attrs(sess, input));
-    for req in sess.opts.prints.iter() {
+    for req in &sess.opts.prints {
         match *req {
             PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
             PrintRequest::FileNames |
@@ -567,7 +567,7 @@ fn print_crate_info(sess: &Session,
                 let crate_types = driver::collect_crate_types(sess, attrs);
                 let metadata = driver::collect_crate_metadata(sess, attrs);
                 *sess.crate_metadata.borrow_mut() = metadata;
-                for &style in crate_types.iter() {
+                for &style in &crate_types {
                     let fname = link::filename_for_input(sess, style,
                                                          id.as_slice(),
                                                          &t_outputs.with_extension(""));
@@ -646,7 +646,7 @@ pub fn monitor<F:FnOnce()+Send>(f: F) {
                             BUG_REPORT_URL),
                     "run with `RUST_BACKTRACE=1` for a backtrace".to_string(),
                 ];
-                for note in xs.iter() {
+                for note in &xs {
                     emitter.emit(None, &note[], None, diagnostic::Note)
                 }
 

src/librustc_driver/test.rs

@@ -147,7 +147,7 @@ impl<'a, 'tcx> Env<'a, 'tcx> {
     }
 
     pub fn create_region_hierarchy(&self, rh: &RH) {
-        for child_rh in rh.sub.iter() {
+        for child_rh in rh.sub {
             self.create_region_hierarchy(child_rh);
             self.infcx.tcx.region_maps.record_encl_scope(
                 CodeExtent::from_node_id(child_rh.id),
@@ -181,7 +181,7 @@ impl<'a, 'tcx> Env<'a, 'tcx> {
                       names: &[String])
                       -> Option<ast::NodeId> {
             assert!(idx < names.len());
-            for item in m.items.iter() {
+            for item in &m.items {
                 if item.ident.user_string(this.infcx.tcx) == names[idx] {
                     return search(this, &**item, idx+1, names);
                 }