diff --git a/src/bootstrap/src/core/build_steps/format.rs b/src/bootstrap/src/core/build_steps/format.rs
index 2deb9168df2ab..b96e26dbb3aea 100644
--- a/src/bootstrap/src/core/build_steps/format.rs
+++ b/src/bootstrap/src/core/build_steps/format.rs
@@ -93,7 +93,7 @@ fn get_modified_rs_files(build: &Builder<'_>) -> Result<Option<Vec<String>>, Str
         return Ok(None);
     }
 
-    get_git_modified_files(&build.config.git_config(), Some(&build.config.src), &vec!["rs"])
+    get_git_modified_files(&build.config.git_config(), Some(&build.config.src), &["rs"])
 }
 
 #[derive(serde_derive::Deserialize)]
diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
index 9f33e4312740f..b4d47cba7c5bc 100644
--- a/src/tools/build-manifest/src/main.rs
+++ b/src/tools/build-manifest/src/main.rs
@@ -495,7 +495,7 @@ impl Builder {
                 Some(p) => p,
                 None => return false,
             };
-            pkg.target.get(&c.target).is_some()
+            pkg.target.contains_key(&c.target)
         };
         extensions.retain(&has_component);
         components.retain(&has_component);
diff --git a/src/tools/build_helper/src/git.rs b/src/tools/build_helper/src/git.rs
index a3c857b0268c9..b4522de6897d4 100644
--- a/src/tools/build_helper/src/git.rs
+++ b/src/tools/build_helper/src/git.rs
@@ -21,7 +21,7 @@ fn output_result(cmd: &mut Command) -> Result<String, String> {
             String::from_utf8(output.stderr).map_err(|err| format!("{err:?}"))?
         ));
     }
-    Ok(String::from_utf8(output.stdout).map_err(|err| format!("{err:?}"))?)
+    String::from_utf8(output.stdout).map_err(|err| format!("{err:?}"))
 }
 
 /// Finds the remote for rust-lang/rust.
@@ -64,18 +64,14 @@ pub fn rev_exists(rev: &str, git_dir: Option<&Path>) -> Result<bool, String> {
     match output.status.code() {
         Some(0) => Ok(true),
         Some(128) => Ok(false),
-        None => {
-            return Err(format!(
-                "git didn't exit properly: {}",
-                String::from_utf8(output.stderr).map_err(|err| format!("{err:?}"))?
-            ));
-        }
-        Some(code) => {
-            return Err(format!(
-                "git command exited with status code: {code}: {}",
-                String::from_utf8(output.stderr).map_err(|err| format!("{err:?}"))?
-            ));
-        }
+        None => Err(format!(
+            "git didn't exit properly: {}",
+            String::from_utf8(output.stderr).map_err(|err| format!("{err:?}"))?
+        )),
+        Some(code) => Err(format!(
+            "git command exited with status code: {code}: {}",
+            String::from_utf8(output.stderr).map_err(|err| format!("{err:?}"))?
+        )),
     }
 }
 
@@ -96,7 +92,7 @@ pub fn updated_master_branch(
         }
     }
 
-    Err(format!("Cannot find any suitable upstream master branch"))
+    Err("Cannot find any suitable upstream master branch".to_owned())
 }
 
 pub fn get_git_merge_base(
@@ -118,7 +114,7 @@ pub fn get_git_merge_base(
 pub fn get_git_modified_files(
     config: &GitConfig<'_>,
     git_dir: Option<&Path>,
-    extensions: &Vec<&str>,
+    extensions: &[&str],
 ) -> Result<Option<Vec<String>>, String> {
     let merge_base = get_git_merge_base(config, git_dir)?;
 
diff --git a/src/tools/compiletest/src/common.rs b/src/tools/compiletest/src/common.rs
index b0047770564c4..da7f03441e72f 100644
--- a/src/tools/compiletest/src/common.rs
+++ b/src/tools/compiletest/src/common.rs
@@ -582,7 +582,7 @@ impl TargetCfgs {
                         name,
                         Some(
                             value
-                                .strip_suffix("\"")
+                                .strip_suffix('\"')
                                 .expect("key-value pair should be properly quoted"),
                         ),
                     )
diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index cc972223f6dfb..ffc706d19a984 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -82,7 +82,7 @@ impl EarlyProps {
             panic!("errors encountered during EarlyProps parsing");
         }
 
-        return props;
+        props
     }
 }
 
@@ -382,7 +382,7 @@ impl TestProps {
                         // Individual flags can be single-quoted to preserve spaces; see
                         // <https://github.com/rust-lang/rust/pull/115948/commits/957c5db6>.
                         flags
-                            .split("'")
+                            .split('\'')
                             .enumerate()
                             .flat_map(|(i, f)| {
                                 if i % 2 == 1 { vec![f] } else { f.split_whitespace().collect() }
@@ -613,7 +613,7 @@ impl TestProps {
 
         for key in &["RUST_TEST_NOCAPTURE", "RUST_TEST_THREADS"] {
             if let Ok(val) = env::var(key) {
-                if self.exec_env.iter().find(|&&(ref x, _)| x == key).is_none() {
+                if !self.exec_env.iter().any(|&(ref x, _)| x == key) {
                     self.exec_env.push(((*key).to_owned(), val))
                 }
             }
@@ -991,7 +991,7 @@ pub(crate) fn check_directive(directive_ln: &str) -> CheckDirectiveResult<'_> {
     let trailing = post.trim().split_once(' ').map(|(pre, _)| pre).unwrap_or(post);
     let trailing_directive = {
         // 1. is the directive name followed by a space? (to exclude `:`)
-        matches!(directive_ln.get(directive_name.len()..), Some(s) if s.starts_with(" "))
+        matches!(directive_ln.get(directive_name.len()..), Some(s) if s.starts_with(' '))
             // 2. is what is after that directive also a directive (ex: "only-x86 only-arm")
             && KNOWN_DIRECTIVE_NAMES.contains(&trailing)
     }
@@ -1363,7 +1363,7 @@ pub fn extract_llvm_version_from_binary(binary_path: &str) -> Option<u32> {
     }
     let version = String::from_utf8(output.stdout).ok()?;
     for line in version.lines() {
-        if let Some(version) = line.split("LLVM version ").skip(1).next() {
+        if let Some(version) = line.split("LLVM version ").nth(1) {
             return extract_llvm_version(version);
         }
     }
@@ -1394,7 +1394,7 @@ where
 
     let min = parse(min)?;
     let max = match max {
-        Some(max) if max.is_empty() => return None,
+        Some("") => return None,
         Some(max) => parse(max)?,
         _ => min,
     };
@@ -1466,12 +1466,12 @@ pub fn make_test_description<R: Read>(
             decision!(ignore_gdb(config, ln));
             decision!(ignore_lldb(config, ln));
 
-            if config.target == "wasm32-unknown-unknown" {
-                if config.parse_name_directive(ln, directives::CHECK_RUN_RESULTS) {
-                    decision!(IgnoreDecision::Ignore {
-                        reason: "ignored on WASM as the run results cannot be checked there".into(),
-                    });
-                }
+            if config.target == "wasm32-unknown-unknown"
+                && config.parse_name_directive(ln, directives::CHECK_RUN_RESULTS)
+            {
+                decision!(IgnoreDecision::Ignore {
+                    reason: "ignored on WASM as the run results cannot be checked there".into(),
+                });
             }
 
             should_fail |= config.parse_name_directive(ln, "should-fail");
diff --git a/src/tools/compiletest/src/header/cfg.rs b/src/tools/compiletest/src/header/cfg.rs
index 510043e3bfd8f..522c52b1de2a7 100644
--- a/src/tools/compiletest/src/header/cfg.rs
+++ b/src/tools/compiletest/src/header/cfg.rs
@@ -58,7 +58,7 @@ pub(super) fn parse_cfg_name_directive<'a>(
 
     // Some of the matchers might be "" depending on what the target information is. To avoid
     // problems we outright reject empty directives.
-    if name == "" {
+    if name.is_empty() {
         return ParsedNameDirective::not_a_directive();
     }
 
diff --git a/src/tools/compiletest/src/lib.rs b/src/tools/compiletest/src/lib.rs
index 62e71e9b59ddb..0cf05b32e9681 100644
--- a/src/tools/compiletest/src/lib.rs
+++ b/src/tools/compiletest/src/lib.rs
@@ -1147,7 +1147,7 @@ fn extract_lldb_version(full_version_line: &str) -> Option<(u32, bool)> {
 }
 
 fn not_a_digit(c: char) -> bool {
-    !c.is_digit(10)
+    !c.is_ascii_digit()
 }
 
 fn check_overlapping_tests(found_paths: &HashSet<PathBuf>) {
diff --git a/src/tools/compiletest/src/read2.rs b/src/tools/compiletest/src/read2.rs
index 3f1921cb6bd5a..8c06339f3c36d 100644
--- a/src/tools/compiletest/src/read2.rs
+++ b/src/tools/compiletest/src/read2.rs
@@ -6,7 +6,6 @@ mod tests;
 
 pub use self::imp::read2;
 use std::io::{self, Write};
-use std::mem::replace;
 use std::process::{Child, Output};
 
 #[derive(Copy, Clone, Debug)]
@@ -101,10 +100,10 @@ impl ProcOutput {
                     return;
                 }
 
-                let mut head = replace(bytes, Vec::new());
+                let mut head = std::mem::take(bytes);
                 // Don't truncate if this as a whole line.
                 // That should make it less likely that we cut a JSON line in half.
-                if head.last() != Some(&('\n' as u8)) {
+                if head.last() != Some(&b'\n') {
                     head.truncate(MAX_OUT_LEN);
                 }
                 let skipped = new_len - head.len();
diff --git a/src/tools/compiletest/src/read2/tests.rs b/src/tools/compiletest/src/read2/tests.rs
index 5ad2db3cb830b..9e052ff069b99 100644
--- a/src/tools/compiletest/src/read2/tests.rs
+++ b/src/tools/compiletest/src/read2/tests.rs
@@ -64,9 +64,9 @@ fn test_abbreviate_filterss_are_detected() {
 #[test]
 fn test_abbreviate_filters_avoid_abbreviations() {
     let mut out = ProcOutput::new();
-    let filters = &[std::iter::repeat('a').take(64).collect::<String>()];
+    let filters = &["a".repeat(64)];
 
-    let mut expected = vec![b'.'; MAX_OUT_LEN - FILTERED_PATHS_PLACEHOLDER_LEN as usize];
+    let mut expected = vec![b'.'; MAX_OUT_LEN - FILTERED_PATHS_PLACEHOLDER_LEN];
     expected.extend_from_slice(filters[0].as_bytes());
 
     out.extend(&expected, filters);
@@ -81,7 +81,7 @@ fn test_abbreviate_filters_avoid_abbreviations() {
 #[test]
 fn test_abbreviate_filters_can_still_cause_abbreviations() {
     let mut out = ProcOutput::new();
-    let filters = &[std::iter::repeat('a').take(64).collect::<String>()];
+    let filters = &["a".repeat(64)];
 
     let mut input = vec![b'.'; MAX_OUT_LEN];
     input.extend_from_slice(filters[0].as_bytes());
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 9e1d5ea61aa8b..72b57d91c234e 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -374,11 +374,11 @@ impl<'test> TestCx<'test> {
 
         // if a test does not crash, consider it an error
         if proc_res.status.success() || matches!(proc_res.status.code(), Some(1 | 0)) {
-            self.fatal(&format!(
+            self.fatal(
                 "test no longer crashes/triggers ICE! Please give it a mearningful name, \
             add a doc-comment to the start of the test explaining why it exists and \
-            move it to tests/ui or wherever you see fit."
-            ));
+            move it to tests/ui or wherever you see fit.",
+            );
         }
     }
 
@@ -697,10 +697,10 @@ impl<'test> TestCx<'test> {
             // since it is extensively used in the testsuite.
             check_cfg.push_str("cfg(FALSE");
             for revision in &self.props.revisions {
-                check_cfg.push_str(",");
-                check_cfg.push_str(&normalize_revision(&revision));
+                check_cfg.push(',');
+                check_cfg.push_str(&normalize_revision(revision));
             }
-            check_cfg.push_str(")");
+            check_cfg.push(')');
 
             cmd.args(&["--check-cfg", &check_cfg]);
         }
@@ -818,7 +818,7 @@ impl<'test> TestCx<'test> {
         // Append the other `cdb-command:`s
         for line in &dbg_cmds.commands {
             script_str.push_str(line);
-            script_str.push_str("\n");
+            script_str.push('\n');
         }
 
         script_str.push_str("qq\n"); // Quit the debugger (including remote debugger, if any)
@@ -1200,7 +1200,7 @@ impl<'test> TestCx<'test> {
         // Append the other commands
         for line in &dbg_cmds.commands {
             script_str.push_str(line);
-            script_str.push_str("\n");
+            script_str.push('\n');
         }
 
         // Finally, quit the debugger
@@ -1250,7 +1250,7 @@ impl<'test> TestCx<'test> {
         // Remove options that are either unwanted (-O) or may lead to duplicates due to RUSTFLAGS.
         let options_to_remove = ["-O".to_owned(), "-g".to_owned(), "--debuginfo".to_owned()];
 
-        options.iter().filter(|x| !options_to_remove.contains(x)).map(|x| x.clone()).collect()
+        options.iter().filter(|x| !options_to_remove.contains(x)).cloned().collect()
     }
 
     fn maybe_add_external_args(&self, cmd: &mut Command, args: &Vec<String>) {
@@ -2504,8 +2504,8 @@ impl<'test> TestCx<'test> {
             // This works with both `--emit asm` (as default output name for the assembly)
             // and `ptx-linker` because the latter can write output at requested location.
             let output_path = self.output_base_name().with_extension(extension);
-            let output_file = TargetLocation::ThisFile(output_path.clone());
-            output_file
+
+            TargetLocation::ThisFile(output_path.clone())
         }
     }
 
@@ -2752,7 +2752,7 @@ impl<'test> TestCx<'test> {
             for entry in walkdir::WalkDir::new(dir) {
                 let entry = entry.expect("failed to read file");
                 if entry.file_type().is_file()
-                    && entry.path().extension().and_then(|p| p.to_str()) == Some("html".into())
+                    && entry.path().extension().and_then(|p| p.to_str()) == Some("html")
                 {
                     let status =
                         Command::new("tidy").args(&tidy_args).arg(entry.path()).status().unwrap();
@@ -2783,8 +2783,7 @@ impl<'test> TestCx<'test> {
             &compare_dir,
             self.config.verbose,
             |file_type, extension| {
-                file_type.is_file()
-                    && (extension == Some("html".into()) || extension == Some("js".into()))
+                file_type.is_file() && (extension == Some("html") || extension == Some("js"))
             },
         ) {
             return;
@@ -2830,11 +2829,11 @@ impl<'test> TestCx<'test> {
                 }
                 match String::from_utf8(line.clone()) {
                     Ok(line) => {
-                        if line.starts_with("+") {
+                        if line.starts_with('+') {
                             write!(&mut out, "{}", line.green()).unwrap();
-                        } else if line.starts_with("-") {
+                        } else if line.starts_with('-') {
                             write!(&mut out, "{}", line.red()).unwrap();
-                        } else if line.starts_with("@") {
+                        } else if line.starts_with('@') {
                             write!(&mut out, "{}", line.blue()).unwrap();
                         } else {
                             out.write_all(line.as_bytes()).unwrap();
@@ -2907,7 +2906,7 @@ impl<'test> TestCx<'test> {
                     && line.ends_with(';')
                 {
                     if let Some(ref mut other_files) = other_files {
-                        other_files.push(line.rsplit("mod ").next().unwrap().replace(";", ""));
+                        other_files.push(line.rsplit("mod ").next().unwrap().replace(';', ""));
                     }
                     None
                 } else {
@@ -3139,7 +3138,7 @@ impl<'test> TestCx<'test> {
             let mut string = String::new();
             for cgu in cgus {
                 string.push_str(&cgu[..]);
-                string.push_str(" ");
+                string.push(' ');
             }
 
             string
@@ -3172,10 +3171,7 @@ impl<'test> TestCx<'test> {
         // CGUs joined with "--". This function splits such composite CGU names
         // and handles each component individually.
         fn remove_crate_disambiguators_from_set_of_cgu_names(cgus: &str) -> String {
-            cgus.split("--")
-                .map(|cgu| remove_crate_disambiguator_from_cgu(cgu))
-                .collect::<Vec<_>>()
-                .join("--")
+            cgus.split("--").map(remove_crate_disambiguator_from_cgu).collect::<Vec<_>>().join("--")
         }
     }
 
@@ -3357,7 +3353,7 @@ impl<'test> TestCx<'test> {
             //   endif
         }
 
-        if self.config.target.contains("msvc") && self.config.cc != "" {
+        if self.config.target.contains("msvc") && !self.config.cc.is_empty() {
             // We need to pass a path to `lib.exe`, so assume that `cc` is `cl.exe`
             // and that `lib.exe` lives next to it.
             let lib = Path::new(&self.config.cc).parent().unwrap().join("lib.exe");
@@ -3639,7 +3635,7 @@ impl<'test> TestCx<'test> {
             //   endif
         }
 
-        if self.config.target.contains("msvc") && self.config.cc != "" {
+        if self.config.target.contains("msvc") && !self.config.cc.is_empty() {
             // We need to pass a path to `lib.exe`, so assume that `cc` is `cl.exe`
             // and that `lib.exe` lives next to it.
             let lib = Path::new(&self.config.cc).parent().unwrap().join("lib.exe");
@@ -3830,7 +3826,7 @@ impl<'test> TestCx<'test> {
             && !self.props.dont_check_compiler_stderr
         {
             self.fatal_proc_rec(
-                &format!("compiler output got truncated, cannot compare with reference file"),
+                "compiler output got truncated, cannot compare with reference file",
                 &proc_res,
             );
         }
@@ -4011,8 +4007,8 @@ impl<'test> TestCx<'test> {
                     crate_name.to_str().expect("crate name implies file name must be valid UTF-8");
                 // replace `a.foo` -> `a__foo` for crate name purposes.
                 // replace `revision-name-with-dashes` -> `revision_name_with_underscore`
-                let crate_name = crate_name.replace(".", "__");
-                let crate_name = crate_name.replace("-", "_");
+                let crate_name = crate_name.replace('.', "__");
+                let crate_name = crate_name.replace('-', "_");
                 rustc.arg("--crate-name");
                 rustc.arg(crate_name);
             }
@@ -4060,7 +4056,7 @@ impl<'test> TestCx<'test> {
     fn check_mir_dump(&self, test_info: MiroptTest) {
         let test_dir = self.testpaths.file.parent().unwrap();
         let test_crate =
-            self.testpaths.file.file_stem().unwrap().to_str().unwrap().replace("-", "_");
+            self.testpaths.file.file_stem().unwrap().to_str().unwrap().replace('-', "_");
 
         let MiroptTest { run_filecheck, suffix, files, passes: _ } = test_info;
 
diff --git a/src/tools/compiletest/src/runtest/debugger.rs b/src/tools/compiletest/src/runtest/debugger.rs
index eebe5f3580b30..ed6cc97a8abba 100644
--- a/src/tools/compiletest/src/runtest/debugger.rs
+++ b/src/tools/compiletest/src/runtest/debugger.rs
@@ -148,5 +148,5 @@ fn check_single_line(line: &str, check_line: &str) -> bool {
         rest = &rest[pos + current_fragment.len()..];
     }
 
-    if !can_end_anywhere && !rest.is_empty() { false } else { true }
+    can_end_anywhere || rest.is_empty()
 }
diff --git a/src/tools/compiletest/src/tests.rs b/src/tools/compiletest/src/tests.rs
index e6725dba26051..4292f234adc78 100644
--- a/src/tools/compiletest/src/tests.rs
+++ b/src/tools/compiletest/src/tests.rs
@@ -58,11 +58,11 @@ fn test_extract_lldb_version() {
 
 #[test]
 fn is_test_test() {
-    assert_eq!(true, is_test(&OsString::from("a_test.rs")));
-    assert_eq!(false, is_test(&OsString::from(".a_test.rs")));
-    assert_eq!(false, is_test(&OsString::from("a_cat.gif")));
-    assert_eq!(false, is_test(&OsString::from("#a_dog_gif")));
-    assert_eq!(false, is_test(&OsString::from("~a_temp_file")));
+    assert!(is_test(&OsString::from("a_test.rs")));
+    assert!(!is_test(&OsString::from(".a_test.rs")));
+    assert!(!is_test(&OsString::from("a_cat.gif")));
+    assert!(!is_test(&OsString::from("#a_dog_gif")));
+    assert!(!is_test(&OsString::from("~a_temp_file")));
 }
 
 #[test]
diff --git a/src/tools/jsondoclint/src/validator.rs b/src/tools/jsondoclint/src/validator.rs
index 5e35ce242fe4e..1713a4d812c4b 100644
--- a/src/tools/jsondoclint/src/validator.rs
+++ b/src/tools/jsondoclint/src/validator.rs
@@ -418,15 +418,13 @@ impl<'a> Validator<'a> {
             } else {
                 self.fail_expecting(id, expected);
             }
-        } else {
-            if !self.missing_ids.contains(id) {
-                self.missing_ids.insert(id);
+        } else if !self.missing_ids.contains(id) {
+            self.missing_ids.insert(id);
 
-                let sels = json_find::find_selector(&self.krate_json, &Value::String(id.0.clone()));
-                assert_ne!(sels.len(), 0);
+            let sels = json_find::find_selector(&self.krate_json, &Value::String(id.0.clone()));
+            assert_ne!(sels.len(), 0);
 
-                self.fail(id, ErrorKind::NotFound(sels))
-            }
+            self.fail(id, ErrorKind::NotFound(sels))
         }
     }
 
diff --git a/src/tools/lint-docs/src/groups.rs b/src/tools/lint-docs/src/groups.rs
index 73f5738469ed1..f246d71d499b4 100644
--- a/src/tools/lint-docs/src/groups.rs
+++ b/src/tools/lint-docs/src/groups.rs
@@ -121,13 +121,13 @@ impl<'a> LintExtractor<'a> {
             };
             to_link.extend(group_lints);
             let brackets: Vec<_> = group_lints.iter().map(|l| format!("[{}]", l)).collect();
-            write!(result, "| {} | {} | {} |\n", group_name, description, brackets.join(", "))
+            writeln!(result, "| {} | {} | {} |", group_name, description, brackets.join(", "))
                 .unwrap();
         }
         result.push('\n');
         result.push_str("[warn-by-default]: listing/warn-by-default.md\n");
         for lint_name in to_link {
-            let lint_def = match lints.iter().find(|l| l.name == lint_name.replace("-", "_")) {
+            let lint_def = match lints.iter().find(|l| l.name == lint_name.replace('-', "_")) {
                 Some(def) => def,
                 None => {
                     let msg = format!(
@@ -144,9 +144,9 @@ impl<'a> LintExtractor<'a> {
                     }
                 }
             };
-            write!(
+            writeln!(
                 result,
-                "[{}]: listing/{}#{}\n",
+                "[{}]: listing/{}#{}",
                 lint_name,
                 lint_def.level.doc_filename(),
                 lint_name
diff --git a/src/tools/lint-docs/src/lib.rs b/src/tools/lint-docs/src/lib.rs
index c79b377727abf..72d6a495e7e79 100644
--- a/src/tools/lint-docs/src/lib.rs
+++ b/src/tools/lint-docs/src/lib.rs
@@ -84,8 +84,8 @@ impl Lint {
         for &expected in &["### Example", "### Explanation", "{{produces}}"] {
             if expected == "{{produces}}" && self.is_ignored() {
                 if self.doc_contains("{{produces}}") {
-                    return Err(format!(
-                        "the lint example has `ignore`, but also contains the {{{{produces}}}} marker\n\
+                    return Err(
+                        "the lint example has `ignore`, but also contains the {{produces}} marker\n\
                         \n\
                         The documentation generator cannot generate the example output when the \
                         example is ignored.\n\
@@ -111,7 +111,7 @@ impl Lint {
                         Replacing the output with the text of the example you \
                         compiled manually yourself.\n\
                         "
-                    ).into());
+                    .into());
                 }
                 continue;
             }
@@ -519,11 +519,11 @@ impl<'a> LintExtractor<'a> {
         let mut these_lints: Vec<_> = lints.iter().filter(|lint| lint.level == level).collect();
         these_lints.sort_unstable_by_key(|lint| &lint.name);
         for lint in &these_lints {
-            write!(result, "* [`{}`](#{})\n", lint.name, lint.name.replace("_", "-")).unwrap();
+            writeln!(result, "* [`{}`](#{})", lint.name, lint.name.replace('_', "-")).unwrap();
         }
         result.push('\n');
         for lint in &these_lints {
-            write!(result, "## {}\n\n", lint.name.replace("_", "-")).unwrap();
+            write!(result, "## {}\n\n", lint.name.replace('_', "-")).unwrap();
             for line in &lint.doc {
                 result.push_str(line);
                 result.push('\n');
@@ -583,7 +583,7 @@ fn add_rename_redirect(level: Level, output: &mut String) {
             let filename = level.doc_filename().replace(".md", ".html");
             output.push_str(RENAME_START);
             for (from, to) in *names {
-                write!(output, "        \"#{from}\": \"{filename}#{to}\",\n").unwrap();
+                writeln!(output, "        \"#{from}\": \"{filename}#{to}\",").unwrap();
             }
             output.push_str(RENAME_END);
         }
diff --git a/src/tools/opt-dist/src/training.rs b/src/tools/opt-dist/src/training.rs
index 89f4d8957c8bf..1237951b3f042 100644
--- a/src/tools/opt-dist/src/training.rs
+++ b/src/tools/opt-dist/src/training.rs
@@ -216,11 +216,9 @@ pub fn gather_bolt_profiles(
     log::info!("Profile file count: {}", profiles.len());
 
     // Delete the gathered profiles
-    for profile in glob::glob(&format!("{profile_prefix}*"))?.into_iter() {
-        if let Ok(profile) = profile {
-            if let Err(error) = std::fs::remove_file(&profile) {
-                log::error!("Cannot delete BOLT profile {}: {error:?}", profile.display());
-            }
+    for profile in glob::glob(&format!("{profile_prefix}*"))?.flatten() {
+        if let Err(error) = std::fs::remove_file(&profile) {
+            log::error!("Cannot delete BOLT profile {}: {error:?}", profile.display());
         }
     }
 
diff --git a/src/tools/remote-test-client/src/main.rs b/src/tools/remote-test-client/src/main.rs
index 590c735596ed9..dd2c09c430b61 100644
--- a/src/tools/remote-test-client/src/main.rs
+++ b/src/tools/remote-test-client/src/main.rs
@@ -317,13 +317,11 @@ fn run(support_lib_count: usize, exe: String, all_args: Vec<String>) {
                 t!(io::copy(&mut (&mut client).take(amt), &mut stdout));
                 t!(stdout.flush());
             }
+        } else if amt == 0 {
+            stderr_done = true;
         } else {
-            if amt == 0 {
-                stderr_done = true;
-            } else {
-                t!(io::copy(&mut (&mut client).take(amt), &mut stderr));
-                t!(stderr.flush());
-            }
+            t!(io::copy(&mut (&mut client).take(amt), &mut stderr));
+            t!(stderr.flush());
         }
     }
 
diff --git a/src/tools/remote-test-server/src/main.rs b/src/tools/remote-test-server/src/main.rs
index 68d7aa56c438b..79f96c5022382 100644
--- a/src/tools/remote-test-server/src/main.rs
+++ b/src/tools/remote-test-server/src/main.rs
@@ -282,7 +282,7 @@ fn handle_run(socket: TcpStream, work: &Path, tmp: &Path, lock: &Mutex<()>, conf
     cmd.env(library_path, env::join_paths(paths).unwrap());
 
     // Some tests assume RUST_TEST_TMPDIR exists
-    cmd.env("RUST_TEST_TMPDIR", tmp.to_owned());
+    cmd.env("RUST_TEST_TMPDIR", tmp);
 
     let socket = Arc::new(Mutex::new(reader.into_inner()));
 
diff --git a/src/tools/tidy/src/alphabetical.rs b/src/tools/tidy/src/alphabetical.rs
index 150a9594350ed..a29286fa2c596 100644
--- a/src/tools/tidy/src/alphabetical.rs
+++ b/src/tools/tidy/src/alphabetical.rs
@@ -88,7 +88,7 @@ fn check_section<'a>(
         let trimmed_line = line.trim_start_matches(' ');
 
         if trimmed_line.starts_with("//")
-            || (trimmed_line.starts_with("#") && !trimmed_line.starts_with("#!"))
+            || (trimmed_line.starts_with('#') && !trimmed_line.starts_with("#!"))
             || trimmed_line.starts_with(is_close_bracket)
         {
             continue;
diff --git a/src/tools/tidy/src/bins.rs b/src/tools/tidy/src/bins.rs
index 64ba79dc1857e..c82e8b6fee98e 100644
--- a/src/tools/tidy/src/bins.rs
+++ b/src/tools/tidy/src/bins.rs
@@ -61,7 +61,7 @@ mod os_impl {
                     fs::remove_file(&path).expect("Deleted temp file");
                     // If the file is executable, then we assume that this
                     // filesystem does not track executability, so skip this check.
-                    return if exec { Unsupported } else { Supported };
+                    if exec { Unsupported } else { Supported }
                 }
                 Err(e) => {
                     // If the directory is read-only or we otherwise don't have rights,
@@ -76,7 +76,7 @@ mod os_impl {
 
                     panic!("unable to create temporary file `{:?}`: {:?}", path, e);
                 }
-            };
+            }
         }
 
         for &source_dir in sources {
@@ -92,7 +92,7 @@ mod os_impl {
             }
         }
 
-        return true;
+        true
     }
 
     // FIXME: check when rust-installer test sh files will be removed,
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index 2dd3d17f9e3e7..7337c9843c7b6 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -699,11 +699,9 @@ fn check_permitted_dependencies(
     for dep in deps {
         let dep = pkg_from_id(metadata, dep);
         // If this path is in-tree, we don't require it to be explicitly permitted.
-        if dep.source.is_some() {
-            if !permitted_dependencies.contains(dep.name.as_str()) {
-                tidy_error!(bad, "Dependency for {descr} not explicitly permitted: {}", dep.id);
-                has_permitted_dep_error = true;
-            }
+        if dep.source.is_some() && !permitted_dependencies.contains(dep.name.as_str()) {
+            tidy_error!(bad, "Dependency for {descr} not explicitly permitted: {}", dep.id);
+            has_permitted_dep_error = true;
         }
     }
 
diff --git a/src/tools/tidy/src/error_codes.rs b/src/tools/tidy/src/error_codes.rs
index 39f7e70b69393..47e2be761e6ab 100644
--- a/src/tools/tidy/src/error_codes.rs
+++ b/src/tools/tidy/src/error_codes.rs
@@ -308,11 +308,9 @@ fn check_error_codes_tests(
         for line in file.lines() {
             let s = line.trim();
             // Assuming the line starts with `error[E`, we can substring the error code out.
-            if s.starts_with("error[E") {
-                if &s[6..11] == code {
-                    found_code = true;
-                    break;
-                }
+            if s.starts_with("error[E") && &s[6..11] == code {
+                found_code = true;
+                break;
             };
         }
 
diff --git a/src/tools/tidy/src/ext_tool_checks.rs b/src/tools/tidy/src/ext_tool_checks.rs
index b54fa5c6b2c92..fb626cac3fa05 100644
--- a/src/tools/tidy/src/ext_tool_checks.rs
+++ b/src/tools/tidy/src/ext_tool_checks.rs
@@ -78,9 +78,9 @@ fn check_impl(
     let mut py_path = None;
 
     let (cfg_args, file_args): (Vec<_>, Vec<_>) = pos_args
-        .into_iter()
+        .iter()
         .map(OsStr::new)
-        .partition(|arg| arg.to_str().is_some_and(|s| s.starts_with("-")));
+        .partition(|arg| arg.to_str().is_some_and(|s| s.starts_with('-')));
 
     if python_lint || python_fmt {
         let venv_path = outdir.join("venv");
@@ -277,10 +277,11 @@ fn create_venv_at_path(path: &Path) -> Result<(), Error> {
 
     let stderr = String::from_utf8_lossy(&out.stderr);
     let err = if stderr.contains("No module named virtualenv") {
-        Error::Generic(format!(
+        Error::Generic(
             "virtualenv not found: you may need to install it \
                                (`python3 -m pip install venv`)"
-        ))
+                .to_owned(),
+        )
     } else {
         Error::Generic(format!(
             "failed to create venv at '{}' using {sys_py}: {stderr}",
diff --git a/src/tools/tidy/src/style.rs b/src/tools/tidy/src/style.rs
index 2d3888ec75f25..7bcb85335e07d 100644
--- a/src/tools/tidy/src/style.rs
+++ b/src/tools/tidy/src/style.rs
@@ -463,10 +463,13 @@ pub fn check(path: &Path, bad: &mut bool) {
                 }
             }
             // for now we just check libcore
-            if trimmed.contains("unsafe {") && !trimmed.starts_with("//") && !last_safety_comment {
-                if file.components().any(|c| c.as_os_str() == "core") && !is_test {
-                    suppressible_tidy_err!(err, skip_undocumented_unsafe, "undocumented unsafe");
-                }
+            if trimmed.contains("unsafe {")
+                && !trimmed.starts_with("//")
+                && !last_safety_comment
+                && file.components().any(|c| c.as_os_str() == "core")
+                && !is_test
+            {
+                suppressible_tidy_err!(err, skip_undocumented_unsafe, "undocumented unsafe");
             }
             if trimmed.contains("// SAFETY:") {
                 last_safety_comment = true;
@@ -487,10 +490,10 @@ pub fn check(path: &Path, bad: &mut bool) {
                     "copyright notices attributed to the Rust Project Developers are deprecated"
                 );
             }
-            if !file.components().any(|c| c.as_os_str() == "rustc_baked_icu_data") {
-                if is_unexplained_ignore(&extension, line) {
-                    err(UNEXPLAINED_IGNORE_DOCTEST_INFO);
-                }
+            if !file.components().any(|c| c.as_os_str() == "rustc_baked_icu_data")
+                && is_unexplained_ignore(&extension, line)
+            {
+                err(UNEXPLAINED_IGNORE_DOCTEST_INFO);
             }
 
             if filename.ends_with(".cpp") && line.contains("llvm_unreachable") {
@@ -525,26 +528,24 @@ pub fn check(path: &Path, bad: &mut bool) {
                         backtick_count += comment_text.chars().filter(|ch| *ch == '`').count();
                     }
                     comment_block = Some((start_line, backtick_count));
-                } else {
-                    if let Some((start_line, backtick_count)) = comment_block.take() {
-                        if backtick_count % 2 == 1 {
-                            let mut err = |msg: &str| {
-                                tidy_error!(bad, "{}:{start_line}: {msg}", file.display());
-                            };
-                            let block_len = (i + 1) - start_line;
-                            if block_len == 1 {
-                                suppressible_tidy_err!(
-                                    err,
-                                    skip_odd_backticks,
-                                    "comment with odd number of backticks"
-                                );
-                            } else {
-                                suppressible_tidy_err!(
-                                    err,
-                                    skip_odd_backticks,
-                                    "{block_len}-line comment block with odd number of backticks"
-                                );
-                            }
+                } else if let Some((start_line, backtick_count)) = comment_block.take() {
+                    if backtick_count % 2 == 1 {
+                        let mut err = |msg: &str| {
+                            tidy_error!(bad, "{}:{start_line}: {msg}", file.display());
+                        };
+                        let block_len = (i + 1) - start_line;
+                        if block_len == 1 {
+                            suppressible_tidy_err!(
+                                err,
+                                skip_odd_backticks,
+                                "comment with odd number of backticks"
+                            );
+                        } else {
+                            suppressible_tidy_err!(
+                                err,
+                                skip_odd_backticks,
+                                "{block_len}-line comment block with odd number of backticks"
+                            );
                         }
                     }
                 }
diff --git a/src/tools/tidy/src/walk.rs b/src/tools/tidy/src/walk.rs
index 63a0383416652..1cecf998e284b 100644
--- a/src/tools/tidy/src/walk.rs
+++ b/src/tools/tidy/src/walk.rs
@@ -79,13 +79,11 @@ pub(crate) fn walk_no_read(
     let walker = walker.filter_entry(move |e| {
         !skip(e.path(), e.file_type().map(|ft| ft.is_dir()).unwrap_or(false))
     });
-    for entry in walker.build() {
-        if let Ok(entry) = entry {
-            if entry.file_type().map_or(true, |kind| kind.is_dir() || kind.is_symlink()) {
-                continue;
-            }
-            f(&entry);
+    for entry in walker.build().flatten() {
+        if entry.file_type().map_or(true, |kind| kind.is_dir() || kind.is_symlink()) {
+            continue;
         }
+        f(&entry);
     }
 }
 
@@ -97,11 +95,9 @@ pub(crate) fn walk_dir(
 ) {
     let mut walker = ignore::WalkBuilder::new(path);
     let walker = walker.filter_entry(move |e| !skip(e.path()));
-    for entry in walker.build() {
-        if let Ok(entry) = entry {
-            if entry.path().is_dir() {
-                f(&entry);
-            }
+    for entry in walker.build().flatten() {
+        if entry.path().is_dir() {
+            f(&entry);
         }
     }
 }
diff --git a/src/tools/tidy/src/x_version.rs b/src/tools/tidy/src/x_version.rs
index c470d502a6548..55bfbed8b0e10 100644
--- a/src/tools/tidy/src/x_version.rs
+++ b/src/tools/tidy/src/x_version.rs
@@ -52,7 +52,7 @@ pub fn check(root: &Path, cargo: &Path, bad: &mut bool) {
             );
         }
     } else {
-        return tidy_error!(bad, "failed to check version of `x`: {}", cargo_list.status);
+        tidy_error!(bad, "failed to check version of `x`: {}", cargo_list.status)
     }
 }