auto merge of #5443 : alexcrichton/rust/less-bad-copy, r=catamorphism

Removes a lot of instances of `/*bad*/ copy` throughout libsyntax/librustc. On the plus side, this shaves about 2s off of the runtime when compiling `librustc` with optimizations.

Ideally I would have run a profiler to figure out which copies are the most critical to remove, but in reality there was a liberal amount of `git grep`s along with some spot checking and removing the easy ones.

Author: bors

src/librustc/back/link.rs

@@ -194,8 +194,7 @@ pub mod write {
             let opts = sess.opts;
             if sess.time_llvm_passes() { llvm::LLVMRustEnableTimePasses(); }
             let mut pm = mk_pass_manager();
-            let td = mk_target_data(
-                /*bad*/copy sess.targ_cfg.target_strs.data_layout);
+            let td = mk_target_data(sess.targ_cfg.target_strs.data_layout);
             llvm::LLVMAddTargetData(td.lltd, pm.llpm);
             // FIXME (#2812): run the linter here also, once there are llvm-c
             // bindings for it.
@@ -866,8 +865,9 @@ pub fn link_binary(sess: Session,
     // to be found at compile time so it is still entirely up to outside
     // forces to make sure that library can be found at runtime.
 
-    let addl_paths = /*bad*/copy sess.opts.addl_lib_search_paths;
-    for addl_paths.each |path| { cc_args.push(~"-L" + path.to_str()); }
+    for sess.opts.addl_lib_search_paths.each |path| {
+        cc_args.push(~"-L" + path.to_str());
+    }
 
     // The names of the extern libraries
     let used_libs = cstore::get_used_libraries(cstore);

src/librustc/back/rpath.rs

@@ -45,8 +45,8 @@ pub fn get_rpath_flags(sess: session::Session, out_filename: &Path)
     // where rustrt is and we know every rust program needs it
     let libs = vec::append_one(libs, get_sysroot_absolute_rt_lib(sess));
 
-    let target_triple = /*bad*/copy sess.opts.target_triple;
-    let rpaths = get_rpaths(os, &sysroot, output, libs, target_triple);
+    let rpaths = get_rpaths(os, &sysroot, output, libs,
+                            sess.opts.target_triple);
     rpaths_to_flags(rpaths)
 }
 
@@ -140,8 +140,8 @@ pub fn get_relative_to(abs1: &Path, abs2: &Path) -> Path {
     let abs2 = abs2.normalize();
     debug!("finding relative path from %s to %s",
            abs1.to_str(), abs2.to_str());
-    let split1 = /*bad*/copy abs1.components;
-    let split2 = /*bad*/copy abs2.components;
+    let split1: &[~str] = abs1.components;
+    let split2: &[~str] = abs2.components;
     let len1 = vec::len(split1);
     let len2 = vec::len(split2);
     fail_unless!(len1 > 0);

src/librustc/driver/driver.rs

@@ -132,15 +132,12 @@ pub fn build_configuration(sess: Session, +argv0: ~str, input: input) ->
 }
 
 // Convert strings provided as --cfg [cfgspec] into a crate_cfg
-fn parse_cfgspecs(cfgspecs: ~[~str],
+fn parse_cfgspecs(+cfgspecs: ~[~str],
                   demitter: diagnostic::Emitter) -> ast::crate_cfg {
-    let mut meta = ~[];
-    for cfgspecs.each |s| {
+    do vec::map_consume(cfgspecs) |s| {
         let sess = parse::new_parse_sess(Some(demitter));
-        let m = parse::parse_meta_from_source_str(~"cfgspec", @/*bad*/ copy *s, ~[], sess);
-        meta.push(m)
+        parse::parse_meta_from_source_str(~"cfgspec", @s, ~[], sess)
     }
-    return meta;
 }
 
 pub enum input {
@@ -580,9 +577,9 @@ pub fn build_session_options(+binary: ~str,
     let debug_map = session::debugging_opts_map();
     for debug_flags.each |debug_flag| {
         let mut this_bit = 0u;
-        for debug_map.each |pair| {
-            let (name, _, bit) = /*bad*/copy *pair;
-            if name == *debug_flag { this_bit = bit; break; }
+        for debug_map.each |tuple| {
+            let (name, bit) = match *tuple { (ref a, _, b) => (a, b) };
+            if name == debug_flag { this_bit = bit; break; }
         }
         if this_bit == 0u {
             early_error(demitter, fmt!("unknown debug flag: %s", *debug_flag))
@@ -647,7 +644,7 @@ pub fn build_session_options(+binary: ~str,
     let target =
         match target_opt {
             None => host_triple(),
-            Some(ref s) => (/*bad*/copy *s)
+            Some(s) => s
         };
 
     let addl_lib_search_paths =

src/librustc/lib/llvm.rs

@@ -1647,7 +1647,7 @@ pub struct TargetData {
     dtor: @target_data_res
 }
 
-pub fn mk_target_data(string_rep: ~str) -> TargetData {
+pub fn mk_target_data(string_rep: &str) -> TargetData {
     let lltd =
         str::as_c_str(string_rep, |buf| unsafe {
             llvm::LLVMCreateTargetData(buf)

src/librustc/metadata/creader.rs

@@ -142,8 +142,8 @@ fn visit_crate(e: @mut Env, c: ast::crate) {
 }
 
 fn visit_view_item(e: @mut Env, i: @ast::view_item) {
-    match /*bad*/copy i.node {
-      ast::view_item_extern_mod(ident, meta_items, id) => {
+    match i.node {
+      ast::view_item_extern_mod(ident, /*bad*/copy meta_items, id) => {
         debug!("resolving extern mod stmt. ident: %?, meta: %?",
                ident, meta_items);
         let cnum = resolve_crate(e, ident, meta_items, @~"", i.span);
@@ -154,8 +154,8 @@ fn visit_view_item(e: @mut Env, i: @ast::view_item) {
 }
 
 fn visit_item(e: @mut Env, i: @ast::item) {
-    match /*bad*/copy i.node {
-      ast::item_foreign_mod(fm) => {
+    match i.node {
+      ast::item_foreign_mod(ref fm) => {
         match attr::foreign_abi(i.attrs) {
           either::Right(abi) => {
             if abi != ast::foreign_abi_cdecl &&

src/librustc/metadata/encoder.rs

@@ -645,7 +645,7 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
     debug!("encoding info for item at %s",
            ecx.tcx.sess.codemap.span_to_str(item.span));
 
-    match /*bad*/copy item.node {
+    match item.node {
       item_const(_, _) => {
         add_to_index();
         ebml_w.start_tag(tag_items_data_item);
@@ -1196,10 +1196,10 @@ fn synthesize_crate_attrs(ecx: @EncodeContext,
             if *attr::get_attr_name(attr) != ~"link" {
                 /*bad*/copy *attr
             } else {
-                match /*bad*/copy attr.node.value.node {
-                  meta_list(_, l) => {
+                match attr.node.value.node {
+                  meta_list(_, ref l) => {
                     found_link_attr = true;;
-                    synthesize_link_attr(ecx, l)
+                    synthesize_link_attr(ecx, /*bad*/copy *l)
                   }
                   _ => /*bad*/copy *attr
                 }

src/librustc/middle/astencode.rs

@@ -639,14 +639,14 @@ fn encode_vtable_origin(ecx: @e::EncodeContext,
                       ebml_w: writer::Encoder,
                       vtable_origin: typeck::vtable_origin) {
     do ebml_w.emit_enum(~"vtable_origin") {
-        match /*bad*/copy vtable_origin {
-          typeck::vtable_static(def_id, tys, vtable_res) => {
+        match vtable_origin {
+          typeck::vtable_static(def_id, ref tys, vtable_res) => {
             do ebml_w.emit_enum_variant(~"vtable_static", 0u, 3u) {
                 do ebml_w.emit_enum_variant_arg(0u) {
                     ebml_w.emit_def_id(def_id)
                 }
                 do ebml_w.emit_enum_variant_arg(1u) {
-                    ebml_w.emit_tys(ecx, /*bad*/copy tys);
+                    ebml_w.emit_tys(ecx, /*bad*/copy *tys);
                 }
                 do ebml_w.emit_enum_variant_arg(2u) {
                     encode_vtable_res(ecx, ebml_w, vtable_res);

src/librustc/middle/borrowck/gather_loans.rs

@@ -139,7 +139,7 @@ fn req_loans_in_expr(ex: @ast::expr,
     }
 
     // Special checks for various kinds of expressions:
-    match /*bad*/copy ex.node {
+    match ex.node {
       ast::expr_addr_of(mutbl, base) => {
         let base_cmt = self.bccx.cat_expr(base);
 
@@ -150,10 +150,10 @@ fn req_loans_in_expr(ex: @ast::expr,
         visit::visit_expr(ex, self, vt);
       }
 
-      ast::expr_call(f, args, _) => {
+      ast::expr_call(f, ref args, _) => {
         let arg_tys = ty::ty_fn_args(ty::expr_ty(self.tcx(), f));
         let scope_r = ty::re_scope(ex.id);
-        for vec::each2(args, arg_tys) |arg, arg_ty| {
+        for vec::each2(*args, arg_tys) |arg, arg_ty| {
             match ty::resolved_mode(self.tcx(), arg_ty.mode) {
                 ast::by_ref => {
                     let arg_cmt = self.bccx.cat_expr(*arg);
@@ -165,11 +165,11 @@ fn req_loans_in_expr(ex: @ast::expr,
         visit::visit_expr(ex, self, vt);
       }
 
-      ast::expr_method_call(rcvr, _, _, args, _) => {
+      ast::expr_method_call(rcvr, _, _, ref args, _) => {
         let arg_tys = ty::ty_fn_args(ty::node_id_to_type(self.tcx(),
                                                          ex.callee_id));
         let scope_r = ty::re_scope(ex.id);
-        for vec::each2(args, arg_tys) |arg, arg_ty| {
+        for vec::each2(*args, arg_tys) |arg, arg_ty| {
             match ty::resolved_mode(self.tcx(), arg_ty.mode) {
                 ast::by_ref => {
                     let arg_cmt = self.bccx.cat_expr(*arg);

src/librustc/middle/check_match.rs

@@ -243,8 +243,8 @@ pub fn is_useful(cx: @MatchCheckCtxt, m: &matrix, v: &[@pat]) -> useful {
               }
               ty::ty_unboxed_vec(*) | ty::ty_evec(*) => {
                 let max_len = do m.foldr(0) |r, max_len| {
-                  match /*bad*/copy r[0].node {
-                    pat_vec(before, _, after) => {
+                  match r[0].node {
+                    pat_vec(ref before, _, ref after) => {
                       uint::max(before.len() + after.len(), max_len)
                     }
                     _ => max_len
@@ -299,7 +299,7 @@ pub fn is_useful_specialized(cx: @MatchCheckCtxt,
 
 pub fn pat_ctor_id(cx: @MatchCheckCtxt, p: @pat) -> Option<ctor> {
     let pat = raw_pat(p);
-    match /*bad*/copy pat.node {
+    match pat.node {
       pat_wild => { None }
       pat_ident(_, _, _) | pat_enum(_, _) => {
         match cx.tcx.def_map.find(&pat.id) {
@@ -324,7 +324,7 @@ pub fn pat_ctor_id(cx: @MatchCheckCtxt, p: @pat) -> Option<ctor> {
       pat_box(_) | pat_uniq(_) | pat_tup(_) | pat_region(*) => {
         Some(single)
       }
-      pat_vec(before, slice, after) => {
+      pat_vec(ref before, slice, ref after) => {
         match slice {
           Some(_) => None,
           None => Some(vec(before.len() + after.len()))
@@ -448,8 +448,8 @@ pub fn missing_ctor(cx: @MatchCheckCtxt,
 }
 
 pub fn ctor_arity(cx: @MatchCheckCtxt, ctor: ctor, ty: ty::t) -> uint {
-    match /*bad*/copy ty::get(ty).sty {
-      ty::ty_tup(fs) => fs.len(),
+    match ty::get(ty).sty {
+      ty::ty_tup(ref fs) => fs.len(),
       ty::ty_box(_) | ty::ty_uniq(_) | ty::ty_rptr(*) => 1u,
       ty::ty_enum(eid, _) => {
           let id = match ctor { variant(id) => id,
@@ -704,7 +704,7 @@ pub fn is_refutable(cx: @MatchCheckCtxt, pat: &pat) -> bool {
       _ => ()
     }
 
-    match /*bad*/copy pat.node {
+    match pat.node {
       pat_box(sub) | pat_uniq(sub) | pat_region(sub) |
       pat_ident(_, _, Some(sub)) => {
         is_refutable(cx, sub)
@@ -715,13 +715,13 @@ pub fn is_refutable(cx: @MatchCheckCtxt, pat: &pat) -> bool {
         false
       }
       pat_lit(_) | pat_range(_, _) => { true }
-      pat_struct(_, fields, _) => {
+      pat_struct(_, ref fields, _) => {
         fields.any(|f| is_refutable(cx, f.pat))
       }
-      pat_tup(elts) => {
+      pat_tup(ref elts) => {
         elts.any(|elt| is_refutable(cx, *elt))
       }
-      pat_enum(_, Some(args)) => {
+      pat_enum(_, Some(ref args)) => {
         args.any(|a| is_refutable(cx, *a))
       }
       pat_enum(_,_) => { false }

src/librustc/middle/const_eval.rs

@@ -81,7 +81,7 @@ pub fn classify(e: @expr,
       Some(x) => x,
       None => {
         let cn =
-            match /*bad*/copy e.node {
+            match e.node {
               ast::expr_lit(lit) => {
                 match lit.node {
                   ast::lit_str(*) |
@@ -101,9 +101,9 @@ pub fn classify(e: @expr,
                      classify(b, def_map, tcx))
               }
 
-              ast::expr_tup(es) |
-              ast::expr_vec(es, ast::m_imm) => {
-                join_all(vec::map(es, |e| classify(*e, def_map, tcx)))
+              ast::expr_tup(ref es) |
+              ast::expr_vec(ref es, ast::m_imm) => {
+                join_all(vec::map(*es, |e| classify(*e, def_map, tcx)))
               }
 
               ast::expr_vstore(e, vstore) => {

src/librustc/middle/freevars.rs

@@ -56,7 +56,7 @@ fn collect_freevars(def_map: resolve::DefMap, blk: &ast::blk)
                     Some(df) => {
                       let mut def = df;
                       while i < depth {
-                        match copy def {
+                        match def {
                           ast::def_upvar(_, inner, _, _) => { def = *inner; }
                           _ => break
                         }

src/librustc/middle/lint.rs

@@ -360,8 +360,8 @@ pub impl Context {
             let metas =
                 attr::attr_metas(attr::find_attrs_by_name(attrs, level_name));
             for metas.each |meta| {
-                match /*bad*/copy meta.node {
-                  ast::meta_list(_, metas) => {
+                match meta.node {
+                  ast::meta_list(_, ref metas) => {
                     for metas.each |meta| {
                         match meta.node {
                           ast::meta_word(ref lintname) => {
@@ -653,8 +653,8 @@ fn check_item_type_limits(cx: ty::ctxt, it: @ast::item) {
 }
 
 fn check_item_default_methods(cx: ty::ctxt, item: @ast::item) {
-    match /*bad*/copy item.node {
-        ast::item_trait(_, _, methods) => {
+    match item.node {
+        ast::item_trait(_, _, ref methods) => {
             for methods.each |method| {
                 match *method {
                     ast::required(*) => {}