more clippy::complexity fixes

compiler/rustc_ast/src/ast.rs

@@ -2466,20 +2466,14 @@ pub enum ModKind {
     Unloaded,
 }
 
-#[derive(Copy, Clone, Encodable, Decodable, Debug)]
+#[derive(Copy, Clone, Encodable, Decodable, Debug, Default)]
 pub struct ModSpans {
     /// `inner_span` covers the body of the module; for a file module, its the whole file.
     /// For an inline module, its the span inside the `{ ... }`, not including the curly braces.
     pub inner_span: Span,
     pub inject_use_span: Span,
 }
 
-impl Default for ModSpans {
-    fn default() -> ModSpans {
-        ModSpans { inner_span: Default::default(), inject_use_span: Default::default() }
-    }
-}
-
 /// Foreign module declaration.
 ///
 /// E.g., `extern { .. }` or `extern "C" { .. }`.

compiler/rustc_data_structures/src/sorted_map.rs

@@ -126,13 +126,13 @@ impl<K: Ord, V> SortedMap<K, V> {
     /// Iterate over the keys, sorted
     #[inline]
     pub fn keys(&self) -> impl Iterator<Item = &K> + ExactSizeIterator + DoubleEndedIterator {
-        self.data.iter().map(|&(ref k, _)| k)
+        self.data.iter().map(|(k, _)| k)
     }
 
     /// Iterate over values, sorted by key
     #[inline]
     pub fn values(&self) -> impl Iterator<Item = &V> + ExactSizeIterator + DoubleEndedIterator {
-        self.data.iter().map(|&(_, ref v)| v)
+        self.data.iter().map(|(_, v)| v)
     }
 
     #[inline]
@@ -222,7 +222,7 @@ impl<K: Ord, V> SortedMap<K, V> {
         K: Borrow<Q>,
         Q: Ord + ?Sized,
     {
-        self.data.binary_search_by(|&(ref x, _)| x.borrow().cmp(key))
+        self.data.binary_search_by(|(x, _)| x.borrow().cmp(key))
     }
 
     #[inline]
@@ -300,7 +300,7 @@ impl<K: Ord, V> FromIterator<(K, V)> for SortedMap<K, V> {
     fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> Self {
         let mut data: Vec<(K, V)> = iter.into_iter().collect();
 
-        data.sort_unstable_by(|&(ref k1, _), &(ref k2, _)| k1.cmp(k2));
+        data.sort_unstable_by(|(k1, _), (k2, _)| k1.cmp(k2));
         data.dedup_by(|&mut (ref k1, _), &mut (ref k2, _)| k1.cmp(k2) == Ordering::Equal);
 
         SortedMap { data }

compiler/rustc_errors/src/emitter.rs

@@ -2313,7 +2313,7 @@ impl FileWithAnnotatedLines {
         }
 
         // Find overlapping multiline annotations, put them at different depths
-        multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, usize::MAX - ml.line_end));
+        multiline_annotations.sort_by_key(|(_, ml)| (ml.line_start, usize::MAX - ml.line_end));
         for (_, ann) in multiline_annotations.clone() {
             for (_, a) in multiline_annotations.iter_mut() {
                 // Move all other multiline annotations overlapping with this one

compiler/rustc_errors/src/lib.rs

@@ -324,7 +324,7 @@ impl CodeSuggestion {
                         // Account for the difference between the width of the current code and the
                         // snippet being suggested, so that the *later* suggestions are correctly
                         // aligned on the screen.
-                        acc += len as isize - (cur_hi.col.0 - cur_lo.col.0) as isize;
+                        acc += len - (cur_hi.col.0 - cur_lo.col.0) as isize;
                     }
                     prev_hi = cur_hi;
                     prev_line = sf.get_line(prev_hi.line - 1);

compiler/rustc_hir_pretty/src/lib.rs

@@ -1757,7 +1757,6 @@ impl<'a> State<'a> {
                 self.print_qpath(qpath, true);
                 self.popen();
                 if let Some(ddpos) = ddpos.as_opt_usize() {
-                    let ddpos = ddpos as usize;
                     self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(p));
                     if ddpos != 0 {
                         self.word_space(",");

compiler/rustc_macros/src/diagnostics/diagnostic.rs

@@ -192,7 +192,7 @@ impl Mismatch {
         let crate_name = std::env::var("CARGO_CRATE_NAME").ok()?;
 
         // If we're not in a "rustc_" crate, bail.
-        let Some(("rustc", slug_prefix)) = crate_name.split_once("_") else { return None };
+        let Some(("rustc", slug_prefix)) = crate_name.split_once('_') else { return None };
 
         let slug_name = slug.segments.first()?.ident.to_string();
         if !slug_name.starts_with(slug_prefix) {

compiler/rustc_session/src/config.rs

@@ -875,18 +875,12 @@ pub struct PacRet {
     pub key: PAuthKey,
 }
 
-#[derive(Clone, Copy, Hash, Debug, PartialEq)]
+#[derive(Clone, Copy, Hash, Debug, PartialEq, Default)]
 pub struct BranchProtection {
     pub bti: bool,
     pub pac_ret: Option<PacRet>,
 }
 
-impl Default for BranchProtection {
-    fn default() -> Self {
-        BranchProtection { bti: false, pac_ret: None }
-    }
-}
-
 pub const fn default_lib_output() -> CrateType {
     CrateType::Rlib
 }
@@ -1875,7 +1869,7 @@ fn parse_opt_level(
         .into_iter()
         .flat_map(|(i, s)| {
             // NB: This can match a string without `=`.
-            if let Some("opt-level") = s.splitn(2, '=').next() { Some(i) } else { None }
+            if let Some("opt-level") = s.split('=').next() { Some(i) } else { None }
         })
         .max();
     if max_o > max_c {
@@ -1912,7 +1906,7 @@ fn select_debuginfo(
         .into_iter()
         .flat_map(|(i, s)| {
             // NB: This can match a string without `=`.
-            if let Some("debuginfo") = s.splitn(2, '=').next() { Some(i) } else { None }
+            if let Some("debuginfo") = s.split('=').next() { Some(i) } else { None }
         })
         .max();
     if max_g > max_c {

compiler/rustc_span/src/analyze_source_file.rs

@@ -175,7 +175,7 @@ cfg_if::cfg_if! {
             // There might still be a tail left to analyze
             let tail_start = chunk_count * CHUNK_SIZE + intra_chunk_offset;
             if tail_start < src.len() {
-                analyze_source_file_generic(&src[tail_start as usize ..],
+                analyze_source_file_generic(&src[tail_start ..],
                                         src.len() - tail_start,
                                         output_offset + BytePos::from_usize(tail_start),
                                         lines,
@@ -219,7 +219,7 @@ fn analyze_source_file_generic(
     while i < scan_len {
         let byte = unsafe {
             // We verified that i < scan_len <= src.len()
-            *src_bytes.get_unchecked(i as usize)
+            *src_bytes.get_unchecked(i)
         };
 
         // How much to advance in order to get to the next UTF-8 char in the

compiler/rustc_span/src/lib.rs

@@ -1381,7 +1381,7 @@ impl<S: Encoder> Encodable<S> for SourceFile {
                     4 => {
                         raw_diffs = Vec::with_capacity(bytes_per_diff * num_diffs);
                         for diff in diff_iter {
-                            raw_diffs.extend_from_slice(&(diff.0 as u32).to_le_bytes());
+                            raw_diffs.extend_from_slice(&(diff.0).to_le_bytes());
                         }
                     }
                     _ => unreachable!(),

compiler/rustc_span/src/source_map.rs

@@ -941,7 +941,7 @@ impl SourceMap {
     /// Otherwise, the span reached to limit is returned.
     pub fn span_look_ahead(&self, span: Span, expect: Option<&str>, limit: Option<usize>) -> Span {
         let mut sp = span;
-        for _ in 0..limit.unwrap_or(100 as usize) {
+        for _ in 0..limit.unwrap_or(100_usize) {
             sp = self.next_point(sp);
             if let Ok(ref snippet) = self.span_to_snippet(sp) {
                 if expect.map_or(false, |es| snippet == es) {

compiler/rustc_target/src/spec/apple_base.rs

@@ -81,7 +81,7 @@ fn pre_link_args(os: &'static str, arch: Arch, abi: &'static str) -> LinkArgs {
         _ => os.into(),
     };
 
-    let platform_version: StaticCow<str> = match os.as_ref() {
+    let platform_version: StaticCow<str> = match os {
         "ios" => ios_lld_platform_version(),
         "tvos" => tvos_lld_platform_version(),
         "watchos" => watchos_lld_platform_version(),

compiler/rustc_target/src/spec/powerpc64_ibm_aix.rs

@@ -5,12 +5,7 @@ pub fn target() -> Target {
     base.max_atomic_width = Some(64);
     base.add_pre_link_args(
         LinkerFlavor::Unix(Cc::No),
-        &[
-            "-b64".into(),
-            "-bpT:0x100000000".into(),
-            "-bpD:0x110000000".into(),
-            "-bcdtors:all:0:s".into(),
-        ],
+        &["-b64", "-bpT:0x100000000", "-bpD:0x110000000", "-bcdtors:all:0:s"],
     );
 
     Target {

compiler/rustc_type_ir/src/sty.rs

@@ -250,9 +250,9 @@ impl<I: Interner> Clone for TyKind<I> {
         match self {
             Bool => Bool,
             Char => Char,
-            Int(i) => Int(i.clone()),
-            Uint(u) => Uint(u.clone()),
-            Float(f) => Float(f.clone()),
+            Int(i) => Int(*i),
+            Uint(u) => Uint(*u),
+            Float(f) => Float(*f),
             Adt(d, s) => Adt(d.clone(), s.clone()),
             Foreign(d) => Foreign(d.clone()),
             Str => Str,
@@ -262,15 +262,15 @@ impl<I: Interner> Clone for TyKind<I> {
             Ref(r, t, m) => Ref(r.clone(), t.clone(), m.clone()),
             FnDef(d, s) => FnDef(d.clone(), s.clone()),
             FnPtr(s) => FnPtr(s.clone()),
-            Dynamic(p, r, repr) => Dynamic(p.clone(), r.clone(), repr.clone()),
+            Dynamic(p, r, repr) => Dynamic(p.clone(), r.clone(), *repr),
             Closure(d, s) => Closure(d.clone(), s.clone()),
             Generator(d, s, m) => Generator(d.clone(), s.clone(), m.clone()),
             GeneratorWitness(g) => GeneratorWitness(g.clone()),
             Never => Never,
             Tuple(t) => Tuple(t.clone()),
             Alias(k, p) => Alias(*k, p.clone()),
             Param(p) => Param(p.clone()),
-            Bound(d, b) => Bound(d.clone(), b.clone()),
+            Bound(d, b) => Bound(*d, b.clone()),
             Placeholder(p) => Placeholder(p.clone()),
             Infer(t) => Infer(t.clone()),
             Error(e) => Error(e.clone()),
@@ -936,7 +936,7 @@ impl<I: Interner> Clone for RegionKind<I> {
     fn clone(&self) -> Self {
         match self {
             ReEarlyBound(r) => ReEarlyBound(r.clone()),
-            ReLateBound(d, r) => ReLateBound(d.clone(), r.clone()),
+            ReLateBound(d, r) => ReLateBound(*d, r.clone()),
             ReFree(r) => ReFree(r.clone()),
             ReStatic => ReStatic,
             ReVar(r) => ReVar(r.clone()),