various clippy fixes

compiler/rustc_ast/src/token.rs

@@ -11,6 +11,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lrc;
 use rustc_macros::HashStable_Generic;
 use rustc_span::symbol::{kw, sym};
+#[allow(clippy::useless_attribute)] // FIXME: following use of `hidden_glob_reexports` incorrectly triggers `useless_attribute` lint.
 #[allow(hidden_glob_reexports)]
 use rustc_span::symbol::{Ident, Symbol};
 use rustc_span::{edition::Edition, ErrorGuaranteed, Span, DUMMY_SP};

compiler/rustc_codegen_llvm/src/context.rs

@@ -326,6 +326,7 @@ pub unsafe fn create_module<'ll>(
     //
     // On the wasm targets it will get hooked up to the "producer" sections
     // `processed-by` information.
+    #[allow(clippy::option_env_unwrap)]
     let rustc_producer =
         format!("rustc version {}", option_env!("CFG_VERSION").expect("CFG_VERSION"));
     let name_metadata = llvm::LLVMMDStringInContext(

compiler/rustc_const_eval/src/interpret/intern.rs

@@ -291,7 +291,9 @@ pub fn intern_const_alloc_for_constprop<
         return Ok(());
     }
     // Move allocation to `tcx`.
-    for _ in intern_shallow(ecx, alloc_id, Mutability::Not).map_err(|()| err_ub!(DeadLocal))? {
+    if let Some(_) =
+        (intern_shallow(ecx, alloc_id, Mutability::Not).map_err(|()| err_ub!(DeadLocal))?).next()
+    {
         // We are not doing recursive interning, so we don't currently support provenance.
         // (If this assertion ever triggers, we should just implement a
         // proper recursive interning loop -- or just call `intern_const_alloc_recursive`.

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -2201,7 +2201,7 @@ impl<D: Decoder> Decodable<D> for EncodedMetadata {
         let mmap = if len > 0 {
             let mut mmap = MmapMut::map_anon(len).unwrap();
             for _ in 0..len {
-                (&mut mmap[..]).write(&[d.read_u8()]).unwrap();
+                (&mut mmap[..]).write_all(&[d.read_u8()]).unwrap();
             }
             mmap.flush().unwrap();
             Some(mmap.make_read_only().unwrap())

compiler/rustc_middle/src/hir/map/mod.rs

@@ -114,20 +114,16 @@ impl<'hir> Iterator for ParentOwnerIterator<'hir> {
         if self.current_id == CRATE_HIR_ID {
             return None;
         }
-        loop {
-            // There are nodes that do not have entries, so we need to skip them.
-            let parent_id = self.map.def_key(self.current_id.owner.def_id).parent;
 
-            let parent_id = parent_id.map_or(CRATE_OWNER_ID, |local_def_index| {
-                let def_id = LocalDefId { local_def_index };
-                self.map.tcx.local_def_id_to_hir_id(def_id).owner
-            });
-            self.current_id = HirId::make_owner(parent_id.def_id);
+        let parent_id = self.map.def_key(self.current_id.owner.def_id).parent;
+        let parent_id = parent_id.map_or(CRATE_OWNER_ID, |local_def_index| {
+            let def_id = LocalDefId { local_def_index };
+            self.map.tcx.local_def_id_to_hir_id(def_id).owner
+        });
+        self.current_id = HirId::make_owner(parent_id.def_id);
 
-            // If this `HirId` doesn't have an entry, skip it and look for its `parent_id`.
-            let node = self.map.tcx.hir_owner_node(self.current_id.owner);
-            return Some((self.current_id.owner, node));
-        }
+        let node = self.map.tcx.hir_owner_node(self.current_id.owner);
+        return Some((self.current_id.owner, node));
     }
 }
 

compiler/rustc_middle/src/mir/interpret/mod.rs

@@ -671,11 +671,11 @@ pub fn read_target_uint(endianness: Endian, mut source: &[u8]) -> Result<u128, i
     // So we do not read exactly 16 bytes into the u128, just the "payload".
     let uint = match endianness {
         Endian::Little => {
-            source.read(&mut buf)?;
+            source.read_exact(&mut buf[..source.len()])?;
             Ok(u128::from_le_bytes(buf))
         }
         Endian::Big => {
-            source.read(&mut buf[16 - source.len()..])?;
+            source.read_exact(&mut buf[16 - source.len()..])?;
             Ok(u128::from_be_bytes(buf))
         }
     };

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

@@ -229,7 +229,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         span: Span,
         scrutinee_span: Span,
     ) -> BlockAnd<()> {
-        let scrutinee_span = scrutinee_span;
         let scrutinee_place =
             unpack!(block = self.lower_scrutinee(block, scrutinee_id, scrutinee_span));
 

compiler/stable_mir/src/mir/alloc.rs

@@ -57,11 +57,11 @@ pub(crate) fn read_target_uint(mut bytes: &[u8]) -> Result<u128, Error> {
     let mut buf = [0u8; std::mem::size_of::<u128>()];
     match MachineInfo::target_endianess() {
         Endian::Little => {
-            bytes.read(&mut buf)?;
+            bytes.read_exact(&mut buf[..bytes.len()])?;
             Ok(u128::from_le_bytes(buf))
         }
         Endian::Big => {
-            bytes.read(&mut buf[16 - bytes.len()..])?;
+            bytes.read_exact(&mut buf[16 - bytes.len()..])?;
             Ok(u128::from_be_bytes(buf))
         }
     }
@@ -72,11 +72,11 @@ pub(crate) fn read_target_int(mut bytes: &[u8]) -> Result<i128, Error> {
     let mut buf = [0u8; std::mem::size_of::<i128>()];
     match MachineInfo::target_endianess() {
         Endian::Little => {
-            bytes.read(&mut buf)?;
+            bytes.read_exact(&mut buf[..bytes.len()])?;
             Ok(i128::from_le_bytes(buf))
         }
         Endian::Big => {
-            bytes.read(&mut buf[16 - bytes.len()..])?;
+            bytes.read_exact(&mut buf[16 - bytes.len()..])?;
             Ok(i128::from_be_bytes(buf))
         }
     }

library/std/src/io/buffered/bufreader.rs

@@ -328,10 +328,9 @@ impl<R: ?Sized + Read> Read for BufReader<R> {
             self.discard_buffer();
             return self.inner.read_vectored(bufs);
         }
-        let nread = {
-            let mut rem = self.fill_buf()?;
-            rem.read_vectored(bufs)?
-        };
+        let mut rem = self.fill_buf()?;
+        let nread = rem.read_vectored(bufs)?;
+
         self.consume(nread);
         Ok(nread)
     }

src/bootstrap/src/core/build_steps/check.rs

@@ -61,21 +61,49 @@ fn args(builder: &Builder<'_>) -> Vec<String> {
             }
         }
 
-        args.extend(strings(&["--", "--cap-lints", "warn"]));
+        args.extend(strings(&["--"]));
+
+        if deny.is_empty() && forbid.is_empty() {
+            args.extend(strings(&["--cap-lints", "warn"]));
+        }
+
+        let all_args = std::env::args().collect::<Vec<_>>();
+        args.extend(get_clippy_rules_in_order(&all_args, allow, deny, warn, forbid));
+
         args.extend(ignored_lints.iter().map(|lint| format!("-Aclippy::{}", lint)));
-        let mut clippy_lint_levels: Vec<String> = Vec::new();
-        allow.iter().for_each(|v| clippy_lint_levels.push(format!("-A{}", v)));
-        deny.iter().for_each(|v| clippy_lint_levels.push(format!("-D{}", v)));
-        warn.iter().for_each(|v| clippy_lint_levels.push(format!("-W{}", v)));
-        forbid.iter().for_each(|v| clippy_lint_levels.push(format!("-F{}", v)));
-        args.extend(clippy_lint_levels);
         args.extend(builder.config.free_args.clone());
         args
     } else {
         builder.config.free_args.clone()
     }
 }
 
+/// We need to keep the order of the given clippy lint rules before passing them.
+/// Since clap doesn't offer any useful interface for this purpose out of the box,
+/// we have to handle it manually.
+pub(crate) fn get_clippy_rules_in_order(
+    all_args: &[String],
+    allow_rules: &[String],
+    deny_rules: &[String],
+    warn_rules: &[String],
+    forbid_rules: &[String],
+) -> Vec<String> {
+    let mut result = vec![];
+
+    for (prefix, item) in
+        [("-A", allow_rules), ("-D", deny_rules), ("-W", warn_rules), ("-F", forbid_rules)]
+    {
+        item.iter().for_each(|v| {
+            let rule = format!("{prefix}{v}");
+            let position = all_args.iter().position(|t| t == &rule).unwrap();
+            result.push((position, rule));
+        });
+    }
+
+    result.sort_by_key(|&(position, _)| position);
+    result.into_iter().map(|v| v.1).collect()
+}
+
 fn cargo_subcommand(kind: Kind) -> &'static str {
     match kind {
         Kind::Check => "check",

src/bootstrap/src/core/config/tests.rs

@@ -1,4 +1,5 @@
 use super::{flags::Flags, ChangeIdWrapper, Config};
+use crate::core::build_steps::check::get_clippy_rules_in_order;
 use crate::core::config::{LldMode, TomlConfig};
 
 use clap::CommandFactory;
@@ -11,12 +12,13 @@ use std::{
 };
 
 fn parse(config: &str) -> Config {
-    let config = format!("{config} \r\n build.rustc = \"/does-not-exists\" ");
     Config::parse_inner(
         &[
-            "check".to_owned(),
-            "--config=/does/not/exist".to_owned(),
-            "--skip-stage0-validation".to_owned(),
+            "check".to_string(),
+            "--set=build.rustc=/does/not/exist".to_string(),
+            "--set=build.cargo=/does/not/exist".to_string(),
+            "--config=/does/not/exist".to_string(),
+            "--skip-stage0-validation".to_string(),
         ],
         |&_| toml::from_str(&config).unwrap(),
     )
@@ -169,7 +171,10 @@ fn override_toml_duplicate() {
     Config::parse_inner(
         &[
             "check".to_owned(),
+            "--set=build.rustc=/does/not/exist".to_string(),
+            "--set=build.cargo=/does/not/exist".to_string(),
             "--config=/does/not/exist".to_owned(),
+            "--skip-stage0-validation".to_owned(),
             "--set=change-id=1".to_owned(),
             "--set=change-id=2".to_owned(),
         ],
@@ -192,7 +197,15 @@ fn profile_user_dist() {
             .and_then(|table: toml::Value| TomlConfig::deserialize(table))
             .unwrap()
     }
-    Config::parse_inner(&["check".to_owned()], get_toml);
+    Config::parse_inner(
+        &[
+            "check".to_owned(),
+            "--set=build.rustc=/does/not/exist".to_string(),
+            "--set=build.cargo=/does/not/exist".to_string(),
+            "--skip-stage0-validation".to_string(),
+        ],
+        get_toml,
+    );
 }
 
 #[test]
@@ -254,3 +267,34 @@ fn parse_change_id_with_unknown_field() {
     let change_id_wrapper: ChangeIdWrapper = toml::from_str(config).unwrap();
     assert_eq!(change_id_wrapper.inner, Some(3461));
 }
+
+#[test]
+fn order_of_clippy_rules() {
+    let args = vec![
+        "clippy".to_string(),
+        "--fix".to_string(),
+        "--allow-dirty".to_string(),
+        "--allow-staged".to_string(),
+        "-Aclippy:all".to_string(),
+        "-Wclippy::style".to_string(),
+        "-Aclippy::foo1".to_string(),
+        "-Aclippy::foo2".to_string(),
+    ];
+    let config = Config::parse(&args);
+
+    let actual = match &config.cmd {
+        crate::Subcommand::Clippy { allow, deny, warn, forbid, .. } => {
+            get_clippy_rules_in_order(&args, &allow, &deny, &warn, &forbid)
+        }
+        _ => panic!("invalid subcommand"),
+    };
+
+    let expected = vec![
+        "-Aclippy:all".to_string(),
+        "-Wclippy::style".to_string(),
+        "-Aclippy::foo1".to_string(),
+        "-Aclippy::foo2".to_string(),
+    ];
+
+    assert_eq!(expected, actual);
+}