Remove redundant clone

src/bootstrap/dist.rs

@@ -1447,8 +1447,8 @@ impl Step for Extended {
         tarballs.extend(rls_installer.clone());
         tarballs.extend(clippy_installer.clone());
         tarballs.extend(rustfmt_installer.clone());
-        tarballs.extend(llvm_tools_installer.clone());
-        tarballs.extend(lldb_installer.clone());
+        tarballs.extend(llvm_tools_installer);
+        tarballs.extend(lldb_installer);
         tarballs.push(analysis_installer);
         tarballs.push(std_installer);
         if builder.config.docs {

src/bootstrap/test.rs

@@ -1052,7 +1052,7 @@ impl Step for Compiletest {
         let hostflags = flags.clone();
         cmd.arg("--host-rustcflags").arg(hostflags.join(" "));
 
-        let mut targetflags = flags.clone();
+        let mut targetflags = flags;
         targetflags.push(format!(
             "-Lnative={}",
             builder.test_helpers_out(target).display()

src/librustc/infer/outlives/obligations.rs

@@ -458,7 +458,7 @@ where
             );
             debug!("projection_must_outlive: unique declared bound appears in trait ref");
             self.delegate
-                .push_sub_region_constraint(origin.clone(), region, unique_bound);
+                .push_sub_region_constraint(origin, region, unique_bound);
             return;
         }
 

src/librustc/infer/region_constraints/mod.rs

@@ -749,7 +749,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
                 a // LUB(a,a) = a
             }
 
-            _ => self.combine_vars(tcx, Lub, a, b, origin.clone()),
+            _ => self.combine_vars(tcx, Lub, a, b, origin),
         }
     }
 
@@ -771,7 +771,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
                 a // GLB(a,a) = a
             }
 
-            _ => self.combine_vars(tcx, Glb, a, b, origin.clone()),
+            _ => self.combine_vars(tcx, Glb, a, b, origin),
         }
     }
 

src/librustc/traits/error_reporting.rs

@@ -239,7 +239,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
             let msg = format!("type mismatch resolving `{}`", predicate);
             let error_id = (DiagnosticMessageId::ErrorId(271),
-                            Some(obligation.cause.span), msg.clone());
+                            Some(obligation.cause.span), msg);
             let fresh = self.tcx.sess.one_time_diagnostics.borrow_mut().insert(error_id);
             if fresh {
                 let mut diag = struct_span_err!(
@@ -379,7 +379,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             }
         }
         if let Some(t) = self.get_parent_trait_ref(&obligation.cause.code) {
-            flags.push(("parent_trait".to_owned(), Some(t.to_string())));
+            flags.push(("parent_trait".to_owned(), Some(t)));
         }
 
         if let Some(k) = obligation.cause.span.compiler_desugaring_kind() {

src/librustc/traits/project.rs

@@ -594,7 +594,7 @@ fn opt_normalize_projection_type<'a, 'b, 'gcx, 'tcx>(
 
             // But for now, let's classify this as an overflow:
             let recursion_limit = *selcx.tcx().sess.recursion_limit.get();
-            let obligation = Obligation::with_depth(cause.clone(),
+            let obligation = Obligation::with_depth(cause,
                                                     recursion_limit,
                                                     param_env,
                                                     projection_ty);

src/librustc/ty/context.rs

@@ -1200,7 +1200,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             cstore,
             global_arenas: &arenas.global,
             global_interners: interners,
-            dep_graph: dep_graph.clone(),
+            dep_graph,
             types: common_types,
             trait_map,
             export_map: resolutions.export_map.into_iter().map(|(k, v)| {

src/librustc_borrowck/borrowck/mod.rs

@@ -695,7 +695,7 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
                 let mut err = self.cannot_act_on_moved_value(use_span,
                                                              verb,
                                                              msg,
-                                                             Some(nl.to_string()),
+                                                             Some(nl),
                                                              Origin::Ast);
                 let need_note = match lp.ty.sty {
                     ty::Closure(id, _) => {

src/librustc_borrowck/borrowck/move_data.rs

@@ -347,7 +347,7 @@ impl<'a, 'tcx> MoveData<'tcx> {
             lp = base_lp.clone();
         }
 
-        self.add_move_helper(tcx, orig_lp.clone(), id, kind);
+        self.add_move_helper(tcx, orig_lp, id, kind);
     }
 
     fn add_move_helper(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
@@ -359,7 +359,7 @@ impl<'a, 'tcx> MoveData<'tcx> {
                id,
                kind);
 
-        let path_index = self.move_path(tcx, lp.clone());
+        let path_index = self.move_path(tcx, lp);
         let move_index = MoveIndex(self.moves.borrow().len());
 
         let next_move = self.path_first_move(path_index);
@@ -402,7 +402,7 @@ impl<'a, 'tcx> MoveData<'tcx> {
             }
         }
 
-        self.add_assignment_helper(tcx, lp.clone(), assign_id, span);
+        self.add_assignment_helper(tcx, lp, assign_id, span);
     }
 
     fn add_assignment_helper(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,

src/librustc_codegen_llvm/base.rs

@@ -784,7 +784,7 @@ pub fn codegen_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
        !tcx.sess.opts.output_types.should_codegen() {
         let ongoing_codegen = write::start_async_codegen(
             tcx,
-            time_graph.clone(),
+            time_graph,
             metadata,
             rx,
             1);

src/librustc_codegen_utils/link.rs

@@ -138,7 +138,7 @@ pub fn filename_for_input(sess: &Session,
             let suffix = &sess.target.target.options.exe_suffix;
             let out_filename = outputs.path(OutputType::Exe);
             if suffix.is_empty() {
-                out_filename.to_path_buf()
+                out_filename
             } else {
                 out_filename.with_extension(&suffix[1..])
             }

src/librustc_mir/borrow_check/error_reporting.rs

@@ -1615,7 +1615,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                 ProjectionElem::Index(..)
                 | ProjectionElem::ConstantIndex { .. }
                 | ProjectionElem::Subslice { .. } => {
-                    self.describe_field(&proj.base, field).to_string()
+                    self.describe_field(&proj.base, field)
                 }
             },
         }

src/librustc_mir/build/matches/mod.rs

@@ -265,7 +265,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                     block,
                     Statement {
                         source_info,
-                        kind: StatementKind::FakeRead(FakeReadCause::ForLet, place.clone()),
+                        kind: StatementKind::FakeRead(FakeReadCause::ForLet, place),
                     },
                 );
 
@@ -314,7 +314,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                     Statement {
                         source_info: ty_source_info,
                         kind: StatementKind::AscribeUserType(
-                            place.clone(),
+                            place,
                             ty::Variance::Invariant,
                             ascription_user_ty,
                         ),

src/librustc_mir/build/matches/test.rs

@@ -324,7 +324,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                     let ref_ty = self.hir.tcx().mk_ref(region, tam);
 
                     // let lhs_ref_place = &lhs;
-                    let ref_rvalue = Rvalue::Ref(region, BorrowKind::Shared, place.clone());
+                    let ref_rvalue = Rvalue::Ref(region, BorrowKind::Shared, place);
                     let lhs_ref_place = self.temp(ref_ty, test.span);
                     self.cfg.push_assign(block, source_info, &lhs_ref_place, ref_rvalue);
                     let val = Operand::Move(lhs_ref_place);

src/librustc_mir/build/mod.rs

@@ -644,7 +644,7 @@ fn construct_fn<'a, 'gcx, 'tcx, A>(hir: Cx<'a, 'gcx, 'tcx>,
         }).collect()
     });
 
-    let mut builder = Builder::new(hir.clone(),
+    let mut builder = Builder::new(hir,
         span,
         arguments.len(),
         safety,
@@ -714,7 +714,7 @@ fn construct_const<'a, 'gcx, 'tcx>(
     let ty = hir.tables().expr_ty_adjusted(ast_expr);
     let owner_id = tcx.hir.body_owner(body_id);
     let span = tcx.hir.span(owner_id);
-    let mut builder = Builder::new(hir.clone(), span, 0, Safety::Safe, ty, ty_span,vec![]);
+    let mut builder = Builder::new(hir, span, 0, Safety::Safe, ty, ty_span,vec![]);
 
     let mut block = START_BLOCK;
     let expr = builder.hir.mirror(ast_expr);

src/librustc_mir/shim.rs

@@ -547,7 +547,7 @@ impl<'a, 'tcx> CloneShimBuilder<'a, 'tcx> {
         // `dest[i] = Clone::clone(src[beg])`;
         // Goto #3 if ok, #5 if unwinding happens.
         let dest_field = dest.clone().index(beg);
-        let src_field = src.clone().index(beg);
+        let src_field = src.index(beg);
         self.make_clone_call(dest_field, src_field, ty, BasicBlock::new(3),
                              BasicBlock::new(5));
 

src/librustc_mir/util/elaborate_drops.rs

@@ -753,11 +753,11 @@ impl<'l, 'b, 'tcx, D> DropCtxt<'l, 'b, 'tcx, D>
                 self.place.clone()
             )));
             drop_block_stmts.push(self.assign(&cur, Rvalue::Cast(
-                CastKind::Misc, Operand::Move(tmp.clone()), iter_ty
+                CastKind::Misc, Operand::Move(tmp), iter_ty
             )));
             drop_block_stmts.push(self.assign(&length_or_end,
                 Rvalue::BinaryOp(BinOp::Offset,
-                     Operand::Copy(cur.clone()), Operand::Move(length.clone())
+                     Operand::Copy(cur), Operand::Move(length)
             )));
         } else {
             // index = 0 (length already pushed)

src/librustc_resolve/build_reduced_graph.rs

@@ -218,7 +218,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                 };
                 this.add_import_directive(
                     base.into_iter().collect(),
-                    subclass.clone(),
+                    subclass,
                     source.ident.span,
                     id,
                     root_use_tree.span,

src/librustc_save_analysis/dump_visitor.rs

@@ -105,7 +105,7 @@ impl<'l, 'tcx: 'l, 'll, O: DumpOutput + 'll> DumpVisitor<'l, 'tcx, 'll, O> {
             tcx: save_ctxt.tcx,
             save_ctxt,
             dumper,
-            span: span_utils.clone(),
+            span: span_utils,
             cur_scope: CRATE_NODE_ID,
             // mac_defs: FxHashSet::default(),
             macro_calls: FxHashSet::default(),

src/librustc_target/spec/mod.rs

@@ -1132,7 +1132,7 @@ impl ToJson for Target {
         macro_rules! target_val {
             ($attr:ident) => ( {
                 let name = (stringify!($attr)).replace("_", "-");
-                d.insert(name.to_string(), self.$attr.to_json());
+                d.insert(name, self.$attr.to_json());
             } );
             ($attr:ident, $key_name:expr) => ( {
                 let name = $key_name;
@@ -1144,7 +1144,7 @@ impl ToJson for Target {
             ($attr:ident) => ( {
                 let name = (stringify!($attr)).replace("_", "-");
                 if default.$attr != self.options.$attr {
-                    d.insert(name.to_string(), self.options.$attr.to_json());
+                    d.insert(name, self.options.$attr.to_json());
                 }
             } );
             ($attr:ident, $key_name:expr) => ( {
@@ -1160,7 +1160,7 @@ impl ToJson for Target {
                         .iter()
                         .map(|(k, v)| (k.desc().to_owned(), v.clone()))
                         .collect::<BTreeMap<_, _>>();
-                    d.insert(name.to_string(), obj.to_json());
+                    d.insert(name, obj.to_json());
                 }
             } );
             (env - $attr:ident) => ( {
@@ -1170,7 +1170,7 @@ impl ToJson for Target {
                         .iter()
                         .map(|&(ref k, ref v)| k.clone() + "=" + &v)
                         .collect::<Vec<_>>();
-                    d.insert(name.to_string(), obj.to_json());
+                    d.insert(name, obj.to_json());
                 }
             } );
 

src/librustc_typeck/check/autoderef.rs

@@ -61,7 +61,7 @@ impl<'a, 'gcx, 'tcx> Iterator for Autoderef<'a, 'gcx, 'tcx> {
             let suggested_limit = *tcx.sess.recursion_limit.get() * 2;
             let msg = format!("reached the recursion limit while auto-dereferencing {:?}",
                               self.cur_ty);
-            let error_id = (DiagnosticMessageId::ErrorId(55), Some(self.span), msg.clone());
+            let error_id = (DiagnosticMessageId::ErrorId(55), Some(self.span), msg);
             let fresh = tcx.sess.one_time_diagnostics.borrow_mut().insert(error_id);
             if fresh {
                 struct_span_err!(tcx.sess,

src/librustc_typeck/check/compare_method.rs

@@ -325,7 +325,7 @@ fn compare_predicate_entailment<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                         diag.span_suggestion_with_applicability(
                             impl_err_span,
                             "consider change the type to match the mutability in trait",
-                            trait_err_str.to_string(),
+                            trait_err_str,
                             Applicability::MachineApplicable,
                         );
                     }

src/librustc_typeck/check/method/probe.rs

@@ -1157,7 +1157,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> {
 
                     // Convert the bounds into obligations.
                     let impl_obligations = traits::predicates_for_generics(
-                        cause.clone(), self.param_env, &impl_bounds);
+                        cause, self.param_env, &impl_bounds);
 
                     debug!("impl_obligations={:?}", impl_obligations);
                     impl_obligations.into_iter()
@@ -1175,7 +1175,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> {
                 TraitCandidate(trait_ref) => {
                     let predicate = trait_ref.to_predicate();
                     let obligation =
-                        traits::Obligation::new(cause.clone(), self.param_env, predicate);
+                        traits::Obligation::new(cause, self.param_env, predicate);
                     if !self.predicate_may_hold(&obligation) {
                         if self.probe(|_| self.select_trait_candidate(trait_ref).is_err()) {
                             // This candidate's primary obligation doesn't even

src/librustc_typeck/check/mod.rs

@@ -4752,25 +4752,17 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         } else if !self.check_for_cast(err, expr, found, expected) {
             let methods = self.get_conversion_methods(expr.span, expected, found);
             if let Ok(expr_text) = self.sess().source_map().span_to_snippet(expr.span) {
-                let suggestions = iter::repeat(expr_text).zip(methods.iter())
+                let suggestions = iter::repeat(&expr_text).zip(methods.iter())
                     .filter_map(|(receiver, method)| {
                         let method_call = format!(".{}()", method.ident);
                         if receiver.ends_with(&method_call) {
                             None  // do not suggest code that is already there (#53348)
                         } else {
-                            /*
-                            methods defined in `method_call_list` will overwrite
-                            `.clone()` in copy of `receiver`
-                            */
                             let method_call_list = [".to_vec()", ".to_string()"];
                             if receiver.ends_with(".clone()")
-                                    && method_call_list.contains(&method_call.as_str()){
-                                // created copy of `receiver` because we don't want other
-                                // suggestion to get affected
-                                let mut new_receiver = receiver.clone();
-                                let max_len = new_receiver.rfind(".").unwrap();
-                                new_receiver.truncate(max_len);
-                                Some(format!("{}{}", new_receiver, method_call))
+                                    && method_call_list.contains(&method_call.as_str()) {
+                                let max_len = receiver.rfind(".").unwrap();
+                                Some(format!("{}{}", &receiver[..max_len], method_call))
                             }
                             else {
                                 Some(format!("{}{}", receiver, method_call))

src/librustdoc/clean/auto_trait.rs

@@ -84,7 +84,7 @@ impl<'a, 'tcx, 'rcx, 'cstore> AutoTraitFinder<'a, 'tcx, 'rcx, 'cstore> {
             .into_iter()
             .chain(self.get_auto_trait_impl_for(
                 def_id,
-                name.clone(),
+                name,
                 generics.clone(),
                 def_ctor,
                 tcx.require_lang_item(lang_items::SyncTraitLangItem),

src/librustdoc/clean/blanket_impl.rs

@@ -66,7 +66,7 @@ impl<'a, 'tcx, 'rcx, 'cstore> BlanketImplFinder <'a, 'tcx, 'rcx, 'cstore> {
         }
         let ty = self.cx.tcx.type_of(def_id);
         let generics = self.cx.tcx.generics_of(def_id);
-        let real_name = name.clone().map(|name| Ident::from_str(&name));
+        let real_name = name.map(|name| Ident::from_str(&name));
         let param_env = self.cx.tcx.param_env(def_id);
         for &trait_def_id in self.cx.all_traits.iter() {
             if !self.cx.renderinfo.borrow().access_levels.is_doc_reachable(trait_def_id) ||
@@ -109,7 +109,7 @@ impl<'a, 'tcx, 'rcx, 'cstore> BlanketImplFinder <'a, 'tcx, 'rcx, 'cstore> {
                         );
                         let may_apply = match infcx.evaluate_obligation(
                             &traits::Obligation::new(
-                                cause.clone(),
+                                cause,
                                 param_env,
                                 trait_ref.to_predicate(),
                             ),

src/librustdoc/clean/mod.rs

@@ -3611,7 +3611,7 @@ impl ToSource for syntax_pos::Span {
     fn to_src(&self, cx: &DocContext) -> String {
         debug!("converting span {:?} to snippet", self.clean(cx));
         let sn = match cx.sess().source_map().span_to_snippet(*self) {
-            Ok(x) => x.to_string(),
+            Ok(x) => x,
             Err(_) => String::new()
         };
         debug!("got snippet {}", sn);

src/librustdoc/html/render.rs

@@ -521,7 +521,7 @@ pub fn run(mut krate: clean::Crate,
             external_html: external_html.clone(),
             krate: krate.name.clone(),
         },
-        css_file_extension: css_file_extension.clone(),
+        css_file_extension,
         created_dirs: Default::default(),
         sort_modules_alphabetically,
         themes,
@@ -1343,7 +1343,7 @@ impl DocFolder for Cache {
                         self.search_index.push(IndexItem {
                             ty: item.type_(),
                             name: s.to_string(),
-                            path: path.join("::").to_string(),
+                            path: path.join("::"),
                             desc: plain_summary_line(item.doc_value()),
                             parent,
                             parent_idx: None,
@@ -2283,7 +2283,7 @@ fn document_short(w: &mut fmt::Formatter, cx: &Context, item: &clean::Item, link
             format!("{} [Read more]({})",
                     &plain_summary_line(Some(s)), naive_assoc_href(item, link))
         } else {
-            plain_summary_line(Some(s)).to_string()
+            plain_summary_line(Some(s))
         };
         render_markdown(w, cx, &markdown, item.links(), prefix)?;
     } else if !prefix.is_empty() {
@@ -2435,7 +2435,7 @@ fn item_module(w: &mut fmt::Formatter, cx: &Context,
     // (which is the position in the vector).
     indices.dedup_by_key(|i| (items[*i].def_id,
                               if items[*i].name.as_ref().is_some() {
-                                  Some(full_path(cx, &items[*i]).clone())
+                                  Some(full_path(cx, &items[*i]))
                               } else {
                                   None
                               },

src/librustdoc/lib.rs

@@ -460,7 +460,7 @@ fn main_args(args: &[String]) -> isize {
     let externs = match parse_externs(&matches) {
         Ok(ex) => ex,
         Err(err) => {
-            diag.struct_err(&err.to_string()).emit();
+            diag.struct_err(&err).emit();
             return 1;
         }
     };

src/librustdoc/test.rs

@@ -208,7 +208,7 @@ fn run_test(test: &str, cratename: &str, filename: &FileName, line: usize,
     // needs to be the result of SourceMap::span_to_unmapped_path
     let input = config::Input::Str {
         name: filename.to_owned(),
-        input: test.to_owned(),
+        input: test,
     };
     let outputs = OutputTypes::new(&[(OutputType::Exe, None)]);
 
@@ -350,7 +350,7 @@ fn run_test(test: &str, cratename: &str, filename: &FileName, line: usize,
     let newpath = {
         let path = env::var_os(var).unwrap_or(OsString::new());
         let mut path = env::split_paths(&path).collect::<Vec<_>>();
-        path.insert(0, libdir.clone());
+        path.insert(0, libdir);
         env::join_paths(path).unwrap()
     };
     cmd.env(var, &newpath);

src/libsyntax/ext/tt/macro_rules.rs

@@ -133,8 +133,7 @@ fn generic_extension<'cx>(cx: &'cx mut ExtCtxt,
                 // Replace all the tokens for the corresponding positions in the macro, to maintain
                 // proper positions in error reporting, while maintaining the macro_backtrace.
                 if rhs_spans.len() == tts.len() {
-                    tts = tts.map_enumerated(|i, tt| {
-                        let mut tt = tt.clone();
+                    tts = tts.map_enumerated(|i, mut tt| {
                         let mut sp = rhs_spans[i];
                         sp = sp.with_ctxt(tt.span().ctxt());
                         tt.set_span(sp);

src/libsyntax/ext/tt/transcribe.rs

@@ -219,9 +219,9 @@ impl Add for LockstepIterSize {
             LockstepIterSize::Unconstrained => other,
             LockstepIterSize::Contradiction(_) => self,
             LockstepIterSize::Constraint(l_len, ref l_id) => match other {
-                LockstepIterSize::Unconstrained => self.clone(),
+                LockstepIterSize::Unconstrained => self,
                 LockstepIterSize::Contradiction(_) => other,
-                LockstepIterSize::Constraint(r_len, _) if l_len == r_len => self.clone(),
+                LockstepIterSize::Constraint(r_len, _) if l_len == r_len => self,
                 LockstepIterSize::Constraint(r_len, r_id) => {
                     let msg = format!("inconsistent lockstep iteration: \
                                        '{}' has {} items, but '{}' has {}",

src/libsyntax/test.rs

@@ -346,7 +346,7 @@ fn mk_main(cx: &mut TestCtxt) -> P<ast::Item> {
 
     test_runner.span = sp;
 
-    let test_main_path_expr = ecx.expr_path(test_runner.clone());
+    let test_main_path_expr = ecx.expr_path(test_runner);
     let call_test_main = ecx.expr_call(sp, test_main_path_expr,
                                        vec![mk_tests_slice(cx)]);
     let call_test_main = ecx.stmt_expr(call_test_main);

src/libsyntax_ext/deriving/cmp/partial_ord.rs

@@ -178,7 +178,7 @@ pub fn cs_partial_cmp(cx: &mut ExtCtxt, span: Span, substr: &Substructure) -> P<
 
                 cx.expr_match(span, new, vec![eq_arm, neq_arm])
             },
-            equals_expr.clone(),
+            equals_expr,
             Box::new(|cx, span, (self_args, tag_tuple), _non_self_args| {
         if self_args.len() != 2 {
             cx.span_bug(span, "not exactly 2 arguments in `derive(PartialOrd)`")

src/libsyntax_ext/deriving/custom.rs

@@ -75,7 +75,7 @@ impl MultiItemModifier for ProcMacroDerive {
         // Mark attributes as known, and used.
         MarkAttrs(&self.attrs).visit_item(&item);
 
-        let input = __internal::new_token_stream(ecx.resolver.eliminate_crate_var(item.clone()));
+        let input = __internal::new_token_stream(ecx.resolver.eliminate_crate_var(item));
         let res = __internal::set_sess(ecx, || {
             let inner = self.inner;
             panic::catch_unwind(panic::AssertUnwindSafe(|| inner(input)))