clippy::complexity fixes

clone_on_copy
useless_format
bind_instead_of_map
filter_map_identity
useless_conversion
map_flatten
unnecessary_unwrap

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1463,10 +1463,9 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
         if let GenericBound::Trait(ref poly, modify) = *bound {
             match (ctxt, modify) {
                 (BoundKind::SuperTraits, TraitBoundModifier::Maybe) => {
-                    let mut err = self.err_handler().struct_span_err(
-                        poly.span,
-                        &format!("`?Trait` is not permitted in supertraits"),
-                    );
+                    let mut err = self
+                        .err_handler()
+                        .struct_span_err(poly.span, "`?Trait` is not permitted in supertraits");
                     let path_str = pprust::path_to_string(&poly.trait_ref.path);
                     err.note(&format!("traits are `?{}` by default", path_str));
                     err.emit();
@@ -1474,7 +1473,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 (BoundKind::TraitObject, TraitBoundModifier::Maybe) => {
                     let mut err = self.err_handler().struct_span_err(
                         poly.span,
-                        &format!("`?Trait` is not permitted in trait object types"),
+                        "`?Trait` is not permitted in trait object types",
                     );
                     err.emit();
                 }

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -450,10 +450,10 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 _ => None,
             };
 
-            if defined_hir.is_some() {
+            if let Some(def_hir) = defined_hir {
                 let upvars_map = self.infcx.tcx.upvars_mentioned(def_id).unwrap();
-                let upvar_def_span = self.infcx.tcx.hir().span(defined_hir.unwrap());
-                let upvar_span = upvars_map.get(&defined_hir.unwrap()).unwrap().span;
+                let upvar_def_span = self.infcx.tcx.hir().span(def_hir);
+                let upvar_span = upvars_map.get(&def_hir).unwrap().span;
                 diag.span_label(upvar_def_span, "variable defined here");
                 diag.span_label(upvar_span, "variable captured here");
             }

compiler/rustc_codegen_ssa/src/mir/place.rs

@@ -462,7 +462,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             }
         };
         for elem in place_ref.projection[base..].iter() {
-            cg_base = match elem.clone() {
+            cg_base = match *elem {
                 mir::ProjectionElem::Deref => {
                     // a box with a non-zst allocator should not be directly dereferenced
                     if cg_base.layout.ty.is_box() && !cg_base.layout.field(cx, 1).is_zst() {

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -520,13 +520,13 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         frame
             .instance
             .try_subst_mir_and_normalize_erasing_regions(*self.tcx, self.param_env, value)
-            .or_else(|e| {
+            .map_err(|e| {
                 self.tcx.sess.delay_span_bug(
                     self.cur_span(),
                     format!("failed to normalize {}", e.get_type_for_failure()).as_str(),
                 );
 
-                Err(InterpError::InvalidProgram(InvalidProgramInfo::TooGeneric))
+                InterpError::InvalidProgram(InvalidProgramInfo::TooGeneric)
             })
     }
 
@@ -1009,11 +1009,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> std::fmt::Debug
                     }
                 }
 
-                write!(
-                    fmt,
-                    ": {:?}",
-                    self.ecx.dump_allocs(allocs.into_iter().filter_map(|x| x).collect())
-                )
+                write!(fmt, ": {:?}", self.ecx.dump_allocs(allocs.into_iter().flatten().collect()))
             }
             Place::Ptr(mplace) => match mplace.ptr.provenance.and_then(Provenance::get_alloc_id) {
                 Some(alloc_id) => write!(

compiler/rustc_log/src/lib.rs

@@ -69,13 +69,7 @@ pub fn init_env_logger(env: &str) -> Result<(), Error> {
 
     let verbose_entry_exit = match env::var_os(String::from(env) + "_ENTRY_EXIT") {
         None => false,
-        Some(v) => {
-            if &v == "0" {
-                false
-            } else {
-                true
-            }
-        }
+        Some(v) => &v != "0",
     };
 
     let layer = tracing_tree::HierarchicalLayer::default()

compiler/rustc_middle/src/mir/patch.rs

@@ -167,8 +167,7 @@ impl<'tcx> MirPatch<'tcx> {
             if loc.statement_index > body[loc.block].statements.len() {
                 let term = body[loc.block].terminator();
                 for i in term.successors() {
-                    stmts_and_targets
-                        .push((Statement { source_info, kind: stmt.clone() }, i.clone()));
+                    stmts_and_targets.push((Statement { source_info, kind: stmt.clone() }, i));
                 }
                 delta += 1;
                 continue;

compiler/rustc_mir_build/src/build/expr/into.rs

@@ -435,11 +435,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         }
                         thir::InlineAsmOperand::SymFn { value, span } => {
                             mir::InlineAsmOperand::SymFn {
-                                value: Box::new(Constant {
-                                    span,
-                                    user_ty: None,
-                                    literal: value.into(),
-                                }),
+                                value: Box::new(Constant { span, user_ty: None, literal: value }),
                             }
                         }
                         thir::InlineAsmOperand::SymStatic { def_id } => {

compiler/rustc_mir_build/src/build/matches/test.rs

@@ -264,7 +264,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     );
                 } else if let [success, fail] = *make_target_blocks(self) {
                     assert_eq!(value.ty(), ty);
-                    let expect = self.literal_operand(test.span, value.into());
+                    let expect = self.literal_operand(test.span, value);
                     let val = Operand::Copy(place);
                     self.compare(block, success, fail, source_info, BinOp::Eq, expect, val);
                 } else {
@@ -277,8 +277,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 let target_blocks = make_target_blocks(self);
 
                 // Test `val` by computing `lo <= val && val <= hi`, using primitive comparisons.
-                let lo = self.literal_operand(test.span, lo.into());
-                let hi = self.literal_operand(test.span, hi.into());
+                let lo = self.literal_operand(test.span, lo);
+                let hi = self.literal_operand(test.span, hi);
                 let val = Operand::Copy(place);
 
                 let [success, fail] = *target_blocks else {
@@ -370,7 +370,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         place: Place<'tcx>,
         mut ty: Ty<'tcx>,
     ) {
-        let mut expect = self.literal_operand(source_info.span, value.into());
+        let mut expect = self.literal_operand(source_info.span, value);
         let mut val = Operand::Copy(place);
 
         // If we're using `b"..."` as a pattern, we need to insert an

compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

@@ -845,7 +845,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let first_provided_ty = if let Some((ty, _)) = final_arg_types[input_idx] {
                             format!(",found `{}`", ty)
                         } else {
-                            "".into()
+                            String::new()
                         };
                         labels.push((
                             first_span,
@@ -857,7 +857,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             if let Some((ty, _)) = final_arg_types[other_input_idx] {
                                 format!(",found `{}`", ty)
                             } else {
-                                "".into()
+                                String::new()
                             };
                         labels.push((
                             second_span,
@@ -875,7 +875,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             let provided_ty = if let Some((ty, _)) = final_arg_types[dst_arg] {
                                 format!(",found `{}`", ty)
                             } else {
-                                "".into()
+                                String::new()
                             };
                             labels.push((
                                 provided_args[dst_arg].span,
@@ -1744,8 +1744,7 @@ fn label_fn_like<'tcx>(
             .get_if_local(def_id)
             .and_then(|node| node.body_id())
             .into_iter()
-            .map(|id| tcx.hir().body(id).params)
-            .flatten();
+            .flat_map(|id| tcx.hir().body(id).params);
 
         for param in params {
             spans.push_span_label(param.span, String::new());

compiler/rustc_typeck/src/check/method/suggest.rs

@@ -492,7 +492,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 Obligation {
                                     cause: cause.clone(),
                                     param_env: self.param_env,
-                                    predicate: predicate.clone(),
+                                    predicate: *predicate,
                                     recursion_depth: 0,
                                 },
                             ));
@@ -676,7 +676,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 let span = self_ty.span.ctxt().outer_expn_data().call_site;
                                 let mut spans: MultiSpan = span.into();
                                 spans.push_span_label(span, derive_msg.to_string());
-                                let entry = spanned_predicates.entry(spans.into());
+                                let entry = spanned_predicates.entry(spans);
                                 entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p);
                             }
 
@@ -704,7 +704,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                     ident.span.into()
                                 };
                                 spans.push_span_label(ident.span, "in this trait".to_string());
-                                let entry = spanned_predicates.entry(spans.into());
+                                let entry = spanned_predicates.entry(spans);
                                 entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p);
                             }
 
@@ -748,7 +748,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 }
                                 spans.push_span_label(self_ty.span, String::new());
 
-                                let entry = spanned_predicates.entry(spans.into());
+                                let entry = spanned_predicates.entry(spans);
                                 entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p);
                             }
                             _ => {}
@@ -1460,7 +1460,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             {
                                 derives.push((
                                     self_name.clone(),
-                                    self_span.clone(),
+                                    self_span,
                                     parent_diagnostic_name.to_string(),
                                 ));
                             }

compiler/rustc_typeck/src/check/op.rs

@@ -705,7 +705,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let predicates = errors
                             .iter()
                             .filter_map(|error| {
-                                error.obligation.predicate.clone().to_opt_poly_trait_pred()
+                                error.obligation.predicate.to_opt_poly_trait_pred()
                             });
                         for pred in predicates {
                             self.infcx.suggest_restricting_param_bound(