remove arithmetic_side_effects

part of #4071

Author: yanns

Cargo.toml

@@ -113,7 +113,6 @@ restriction = { level = "warn", priority = -2 }
 
 # lints to decide on
 
-arithmetic_side_effects = "allow" # TODO: consider
 as_conversions = "allow" # TODO: tricky
 cast_possible_truncation = "allow" # TODO: consider
 cast_precision_loss = "allow" # TODO: consider

src/body/length.rs

@@ -70,7 +70,7 @@ impl DecodedLength {
         match *self {
             DecodedLength::CHUNKED | DecodedLength::CLOSE_DELIMITED => (),
             DecodedLength(ref mut known) => {
-                *known -= amt;
+                *known = known.saturating_sub(amt);
             }
         }
     }

src/common/buf.rs

@@ -38,6 +38,7 @@ impl<T: Buf> Buf for BufList<T> {
     }
 
     #[inline]
+    #[allow(clippy::arithmetic_side_effects)]
     fn advance(&mut self, mut cnt: usize) {
         while cnt > 0 {
             {
@@ -56,6 +57,7 @@ impl<T: Buf> Buf for BufList<T> {
     }
 
     #[inline]
+    #[allow(clippy::arithmetic_side_effects)]
     fn chunks_vectored<'t>(&'t self, dst: &mut [IoSlice<'t>]) -> usize {
         if dst.is_empty() {
             return 0;

src/common/date.rs

@@ -67,6 +67,7 @@ impl CachedDate {
         }
     }
 
+    #[allow(clippy::arithmetic_side_effects)]
     fn update(&mut self, now: SystemTime) {
         let nanos = now
             .duration_since(UNIX_EPOCH)
@@ -95,6 +96,7 @@ impl CachedDate {
 }
 
 impl fmt::Write for CachedDate {
+    #[allow(clippy::arithmetic_side_effects)]
     fn write_str(&mut self, s: &str) -> fmt::Result {
         let len = s.len();
         self.bytes[self.pos..self.pos + len].copy_from_slice(s.as_bytes());

src/common/io/compat.rs

@@ -24,6 +24,7 @@ where
     T: crate::rt::Read,
 {
     /// `poll_read` fn implementation for `Compat<T>`.
+    #[allow(clippy::arithmetic_side_effects)]
     fn poll_read(
         self: Pin<&mut Self>,
         cx: &mut Context<'_>,

src/ext/h1_reason_phrase.rs

@@ -157,6 +157,7 @@ const fn is_valid_byte(b: u8) -> bool {
     b == b'\t' || b == b' ' || is_vchar(b) || is_obs_text(b)
 }
 
+#[allow(clippy::arithmetic_side_effects)]
 const fn find_invalid_byte(bytes: &[u8]) -> Option<u8> {
     let mut i = 0;
     while i < bytes.len() {

src/headers.rs

@@ -67,6 +67,7 @@ pub(super) fn content_length_parse_all_values(values: ValueIter<'_, HeaderValue>
     content_length
 }
 
+#[allow(clippy::arithmetic_side_effects)]
 fn from_digits(bytes: &[u8]) -> Option<u64> {
     // cannot use FromStr for u64, since it allows a signed prefix
     let mut result = 0u64;
@@ -137,6 +138,7 @@ pub(super) fn is_chunked_(value: &HeaderValue) -> bool {
 }
 
 #[cfg(all(feature = "client", feature = "http1"))]
+#[allow(clippy::arithmetic_side_effects)]
 pub(super) fn add_chunked(mut entry: http::header::OccupiedEntry<'_, HeaderValue>) {
     const CHUNKED: &str = "chunked";
 

src/proto/h1/conn.rs

@@ -208,6 +208,7 @@ where
         read_buf.len() >= 24 && read_buf[..24] == *H2_PREFACE
     }
 
+    #[allow(clippy::arithmetic_side_effects)]
     pub(super) fn poll_read_head(
         &mut self,
         cx: &mut Context<'_>,

src/proto/h1/decode.rs

@@ -141,6 +141,7 @@ impl Decoder {
         )
     }
 
+    #[allow(clippy::arithmetic_side_effects)]
     pub(crate) fn decode<R: MemRead>(
         &mut self,
         cx: &mut Context<'_>,
@@ -339,6 +340,7 @@ impl ChunkedState {
         }
     }
 
+    #[allow(clippy::arithmetic_side_effects)]
     fn read_start<R: MemRead>(
         cx: &mut Context<'_>,
         rdr: &mut R,
@@ -371,6 +373,7 @@ impl ChunkedState {
         Poll::Ready(Ok(ChunkedState::Size))
     }
 
+    #[allow(clippy::arithmetic_side_effects)]
     fn read_size<R: MemRead>(
         cx: &mut Context<'_>,
         rdr: &mut R,
@@ -420,6 +423,7 @@ impl ChunkedState {
             ))),
         }
     }
+    #[allow(clippy::arithmetic_side_effects)]
     fn read_extension<R: MemRead>(
         cx: &mut Context<'_>,
         rdr: &mut R,
@@ -473,6 +477,7 @@ impl ChunkedState {
         }
     }
 
+    #[allow(clippy::arithmetic_side_effects)]
     fn read_body<R: MemRead>(
         cx: &mut Context<'_>,
         rdr: &mut R,
@@ -548,6 +553,7 @@ impl ChunkedState {
         }
     }
 
+    #[allow(clippy::arithmetic_side_effects)]
     fn read_trailer_lf<R: MemRead>(
         cx: &mut Context<'_>,
         rdr: &mut R,

src/proto/h1/encode.rs

@@ -125,6 +125,7 @@ impl Encoder {
         }
     }
 
+    #[allow(clippy::arithmetic_side_effects)]
     pub(crate) fn encode<B>(&mut self, msg: B) -> EncodedBuf<B>
     where
         B: Buf,
@@ -359,6 +360,7 @@ impl ChunkSize {
 
 impl Buf for ChunkSize {
     #[inline]
+    #[allow(clippy::arithmetic_side_effects)]
     fn remaining(&self) -> usize {
         (self.len - self.pos).into()
     }
@@ -369,6 +371,7 @@ impl Buf for ChunkSize {
     }
 
     #[inline]
+    #[allow(clippy::arithmetic_side_effects)]
     fn advance(&mut self, cnt: usize) {
         assert!(cnt <= self.remaining());
         self.pos += cnt as u8; // just asserted cnt fits in u8
@@ -385,6 +388,7 @@ impl fmt::Debug for ChunkSize {
 }
 
 impl fmt::Write for ChunkSize {
+    #[allow(clippy::arithmetic_side_effects)]
     fn write_str(&mut self, num: &str) -> fmt::Result {
         use std::io::Write;
         (&mut self.bytes[self.len.into()..])