Rollup merge of #121543 - onur-ozkan:clippy-args, r=oli-obk

various clippy fixes

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.

Additionally, this PR makes `-D` rules work as expected. Previously, lint rules were limited to `-W`. By enabling `-D`, clippy began to complain numerous lines in the tree, all of which have been resolved in this PR as well.

Fixes #121481
cc `@matthiaskrgr`

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

@@ -315,6 +315,7 @@ 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

@@ -293,7 +293,9 @@ 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

@@ -2198,7 +2198,7 @@ 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

@@ -76,20 +76,16 @@ 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 parent_id = self.map.def_key(self.current_id.owner.def_id).parent;
-                let def_id = LocalDefId { local_def_index };
+        let parent_id = parent_id.map_or(CRATE_OWNER_ID, |local_def_index| {
-                self.map.tcx.local_def_id_to_hir_id(def_id).owner
+            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);
+        });
+        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);
-            let node = self.map.tcx.hir_owner_node(self.current_id.owner);
+        return Some((self.current_id.owner, node));
-            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()?;
-            let mut rem = self.fill_buf()?;
+        let nread = rem.read_vectored(bufs)?;
-            rem.read_vectored(bufs)?
+
-        };
         self.consume(nread);
         Ok(nread)
     }

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

@@ -61,14 +61,16 @@ 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 {
@@ -76,6 +78,32 @@ fn args(builder: &Builder<'_>) -> Vec<String> {
     }
 }
 
+/// 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(),
+            "check".to_string(),
-            "--config=/does/not/exist".to_owned(),
+            "--set=build.rustc=/does/not/exist".to_string(),
-            "--skip-stage0-validation".to_owned(),
+            "--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);
+}