resolve clippy errors

Signed-off-by: onur-ozkan <work@onurozkan.dev>

Author: onur-ozkan

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)?;
+ let _ = source.read(&mut buf)?;
  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)?;
+ let _ = bytes.read(&mut buf)?;
  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)?;
+ let _ = bytes.read(&mut buf)?;
  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)
  }