Auto merge of #126446 - workingjubilee:rollup-esdbgdw, r=workingjubilee

Rollup of 8 pull requests

Successful merges:

 - #121216 (Always emit `native-static-libs` note, even if it is empty)
 - #123726 (Clarify `Command::new` behavior for programs with arguments)
 - #125722 (Indicate in `non_local_defs` lint that the macro needs to change)
 - #126088 ([1/2] clean-up / general improvements)
 - #126390 (Fix wording in {checked_}next_power_of_two)
 - #126392 (Small style improvement in `gvn.rs`)
 - #126402 (Fix wrong `assert_unsafe_precondition` message for `core::ptr::copy`)
 - #126445 (Remove failing GUI test to stop blocking CI until it is fixed)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1561,17 +1561,13 @@ fn print_native_static_libs(
     match out {
         OutFileName::Real(path) => {
             out.overwrite(&lib_args.join(" "), sess);
-            if !lib_args.is_empty() {
-                sess.dcx().emit_note(errors::StaticLibraryNativeArtifactsToFile { path });
-            }
+            sess.dcx().emit_note(errors::StaticLibraryNativeArtifactsToFile { path });
         }
         OutFileName::Stdout => {
-            if !lib_args.is_empty() {
-                sess.dcx().emit_note(errors::StaticLibraryNativeArtifacts);
-                // Prefix for greppability
-                // Note: This must not be translated as tools are allowed to depend on this exact string.
-                sess.dcx().note(format!("native-static-libs: {}", &lib_args.join(" ")));
-            }
+            sess.dcx().emit_note(errors::StaticLibraryNativeArtifacts);
+            // Prefix for greppability
+            // Note: This must not be translated as tools are allowed to depend on this exact string.
+            sess.dcx().note(format!("native-static-libs: {}", &lib_args.join(" ")));
         }
     }
 }

compiler/rustc_lint/messages.ftl

@@ -550,6 +550,7 @@ lint_non_local_definitions_impl = non-local `impl` definition, `impl` blocks sho
     .bounds = `impl` may be usable in bounds, etc. from outside the expression, which might e.g. make something constructible that previously wasn't, because it's still on a publicly-visible type
     .exception = items in an anonymous const item (`const _: () = {"{"} ... {"}"}`) are treated as in the same scope as the anonymous const's declaration
     .const_anon = use a const-anon item to suppress this lint
+    .macro_to_change = the {$macro_kind} `{$macro_to_change}` defines the non-local `impl`, and may need to be changed
 
 lint_non_local_definitions_impl_move_help =
     move the `impl` block outside of this {$body_kind_descr} {$depth ->

compiler/rustc_lint/src/lints.rs

@@ -1362,6 +1362,7 @@ pub enum NonLocalDefinitionsDiag {
         has_trait: bool,
         self_ty_str: String,
         of_trait_str: Option<String>,
+        macro_to_change: Option<(String, &'static str)>,
     },
     MacroRules {
         depth: u32,
@@ -1387,6 +1388,7 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                 has_trait,
                 self_ty_str,
                 of_trait_str,
+                macro_to_change,
             } => {
                 diag.primary_message(fluent::lint_non_local_definitions_impl);
                 diag.arg("depth", depth);
@@ -1397,6 +1399,15 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                     diag.arg("of_trait_str", of_trait_str);
                 }
 
+                if let Some((macro_to_change, macro_kind)) = macro_to_change {
+                    diag.arg("macro_to_change", macro_to_change);
+                    diag.arg("macro_kind", macro_kind);
+                    diag.note(fluent::lint_macro_to_change);
+                }
+                if let Some(cargo_update) = cargo_update {
+                    diag.subdiagnostic(&diag.dcx, cargo_update);
+                }
+
                 if has_trait {
                     diag.note(fluent::lint_bounds);
                     diag.note(fluent::lint_with_trait);
@@ -1422,9 +1433,6 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                     );
                 }
 
-                if let Some(cargo_update) = cargo_update {
-                    diag.subdiagnostic(&diag.dcx, cargo_update);
-                }
                 if let Some(const_anon) = const_anon {
                     diag.note(fluent::lint_exception);
                     if let Some(const_anon) = const_anon {

compiler/rustc_lint/src/non_local_def.rs

@@ -258,6 +258,13 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                     Some((cx.tcx.def_span(parent), may_move))
                 };
 
+                let macro_to_change =
+                    if let ExpnKind::Macro(kind, name) = item.span.ctxt().outer_expn_data().kind {
+                        Some((name.to_string(), kind.descr()))
+                    } else {
+                        None
+                    };
+
                 cx.emit_span_lint(
                     NON_LOCAL_DEFINITIONS,
                     ms,
@@ -274,6 +281,7 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                         move_to,
                         may_remove,
                         has_trait: impl_.of_trait.is_some(),
+                        macro_to_change,
                     },
                 )
             }

compiler/rustc_mir_transform/src/gvn.rs

@@ -330,8 +330,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
         let is_sized = !self.feature_unsized_locals
             || self.local_decls[local].ty.is_sized(self.tcx, self.param_env);
         if is_sized {
-            self.rev_locals.ensure_contains_elem(value, SmallVec::new);
-            self.rev_locals[value].push(local);
+            self.rev_locals.ensure_contains_elem(value, SmallVec::new).push(local);
         }
     }
 

library/core/src/intrinsics.rs

@@ -3043,8 +3043,7 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
     unsafe {
         ub_checks::assert_unsafe_precondition!(
             check_language_ub,
-            "ptr::copy_nonoverlapping requires that both pointer arguments are aligned and non-null \
-            and the specified memory ranges do not overlap",
+            "ptr::copy requires that both pointer arguments are aligned and non-null",
             (
                 src: *const () = src as *const (),
                 dst: *mut () = dst as *mut (),

library/core/src/num/nonzero.rs

@@ -1059,7 +1059,7 @@ macro_rules! nonzero_integer_signedness_dependent_methods {
             unsafe { Self::new_unchecked(self.get().unchecked_add(other)) }
         }
 
-        /// Returns the smallest power of two greater than or equal to n.
+        /// Returns the smallest power of two greater than or equal to `self`.
         /// Checks for overflow and returns [`None`]
         /// if the next power of two is greater than the type’s maximum value.
         /// As a consequence, the result cannot wrap to zero.

library/core/src/num/uint_macros.rs

@@ -2830,7 +2830,7 @@ macro_rules! uint_impl {
         ///
         /// When return value overflows (i.e., `self > (1 << (N-1))` for type
         /// `uN`), it panics in debug mode and the return value is wrapped to 0 in
-        /// release mode (the only situation in which method can return 0).
+        /// release mode (the only situation in which this method can return 0).
         ///
         /// # Examples
         ///
@@ -2851,7 +2851,7 @@ macro_rules! uint_impl {
             self.one_less_than_next_power_of_two() + 1
         }
 
-        /// Returns the smallest power of two greater than or equal to `n`. If
+        /// Returns the smallest power of two greater than or equal to `self`. If
         /// the next power of two is greater than the type's maximum value,
         /// `None` is returned, otherwise the power of two is wrapped in `Some`.
         ///

library/std/src/process.rs

@@ -629,6 +629,25 @@ impl Command {
     ///     .spawn()
     ///     .expect("sh command failed to start");
     /// ```
+    ///
+    /// # Caveats
+    ///
+    /// [`Command::new`] is only intended to accept the path of the program. If you pass a program
+    /// path along with arguments like `Command::new("ls -l").spawn()`, it will try to search for
+    /// `ls -l` literally. The arguments need to be passed separately, such as via [`arg`] or
+    /// [`args`].
+    ///
+    /// ```no_run
+    /// use std::process::Command;
+    ///
+    /// Command::new("ls")
+    ///     .arg("-l") // arg passed separately
+    ///     .spawn()
+    ///     .expect("ls command failed to start");
+    /// ```
+    ///
+    /// [`arg`]: Self::arg
+    /// [`args`]: Self::args
     #[stable(feature = "process", since = "1.0.0")]
     pub fn new<S: AsRef<OsStr>>(program: S) -> Command {
         Command { inner: imp::Command::new(program.as_ref()) }

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)]

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);

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)?;
 

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"),
                         ),
                     )

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");

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();
     }
 

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>) {

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();

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());

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;
 

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()
 }

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]

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))
         }
     }
 

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

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);
         }

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());
         }
     }
 

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());
         }
     }
 

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()));
 

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;

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,

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;
         }
     }
 

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;
             };
         }
 

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}",

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"
+                            );
                         }
                     }
                 }

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);
         }
     }
 }

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)
     }
 }
 

tests/rustdoc-gui/help-page.goml

@@ -0,0 +1,14 @@
+// Test that linking a no_std application still outputs the
+// `native-static-libs: ` note, even though it's empty.
+//@ compile-flags: -Cpanic=abort --print=native-static-libs
+//@ build-pass
+//@ ignore-wasm
+//@ ignore-cross-compile This doesn't produce any output on i686-unknown-linux-gnu for some reason?
+
+#![crate_type = "staticlib"]
+#![no_std]
+
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    loop {}
+}

tests/ui/codegen/empty-static-libs-issue-108825.rs

@@ -0,0 +1,4 @@
+note: Link against the following native artifacts when linking against this static library. The order and any duplication can be significant on some platforms.
+
+note: native-static-libs: 
+

tests/ui/codegen/empty-static-libs-issue-108825.stderr

@@ -8,9 +8,10 @@ LL | non_local_macro::non_local_impl!(LocalStruct);
    | `Debug` is not local
    | move the `impl` block outside of this constant `_IMPL_DEBUG`
    |
+   = note: the macro `non_local_macro::non_local_impl` defines the non-local `impl`, and may need to be changed
+   = note: the macro `non_local_macro::non_local_impl` may come from an old version of the `non_local_macro` crate, try updating your dependency with `cargo update -p non_local_macro`
    = note: `impl` may be usable in bounds, etc. from outside the expression, which might e.g. make something constructible that previously wasn't, because it's still on a publicly-visible type
    = note: an `impl` is never scoped, even when it is nested inside an item, as it may impact type checking outside of that item, which can be the case if neither the trait or the self type are at the same nesting level as the `impl`
-   = note: the macro `non_local_macro::non_local_impl` may come from an old version of the `non_local_macro` crate, try updating your dependency with `cargo update -p non_local_macro`
    = note: items in an anonymous const item (`const _: () = { ... }`) are treated as in the same scope as the anonymous const's declaration
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
    = note: `#[warn(non_local_definitions)]` on by default

tests/ui/lint/non-local-defs/cargo-update.stderr

@@ -12,6 +12,7 @@ LL |             impl MacroTrait for OutsideStruct {}
 LL | m!();
    | ---- in this macro invocation
    |
+   = note: the macro `m` defines the non-local `impl`, and may need to be changed
    = note: `impl` may be usable in bounds, etc. from outside the expression, which might e.g. make something constructible that previously wasn't, because it's still on a publicly-visible type
    = note: an `impl` is never scoped, even when it is nested inside an item, as it may impact type checking outside of that item, which can be the case if neither the trait or the self type are at the same nesting level as the `impl`
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>