Fix clippy lints for Rust 1.88 (#377)

Fixes the lints for the bump to Rust 1.88

Author: nekevss

.cargo/config.toml

@@ -0,0 +1,3 @@
+# TODO: track https://github.com/rust-lang/rust/issues/141626 for a resolution
+[target.x86_64-pc-windows-msvc]
+rustflags = ['-Csymbol-mangling-version=v0']

.github/workflows/rust.yml

@@ -12,14 +12,22 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  RUSTFLAGS: -Dwarnings
+  FLAGS: ${{ (github.ref == 'refs/heads/main' || github.base_ref == 'main') && '-D warnings' || '' }}
   CARGO_TERM_COLOR: always
 
 jobs:
   lint:
     name: Lint
     runs-on: ubuntu-latest
     steps:
+      - name: Set environment
+        # Setting `RUSTFLAGS` overrides any flags set on .cargo/config.toml, so we need to
+        # set the target flags instead which are cumulative.
+        # Track https://github.com/rust-lang/cargo/issues/5376
+        run: |
+          target=$(rustc -vV | awk '/^host/ { print $2 }' | tr [:lower:] [:upper:] | tr '-' '_')
+          echo "CARGO_TARGET_${target}_RUSTFLAGS=$FLAGS" >> $GITHUB_ENV
+
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
         with:
@@ -43,6 +51,11 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 60
     steps:
+      - name: Set environment
+        run: |
+          target=$(rustc -vV | awk '/^host/ { print $2 }' | tr [:lower:] [:upper:] | tr '-' '_')
+          echo "CARGO_TARGET_${target}_RUSTFLAGS=$FLAGS" >> $GITHUB_ENV
+
       - name: Checkout repository
         uses: actions/checkout@v4
 
@@ -61,6 +74,11 @@ jobs:
 
   build-test:
     name: Test (${{ matrix.rust.name }}, ${{ matrix.os }})
+    env:
+      RUSTUP_WINDOWS_PATH_ADD_BIN: 1
+      # NOTE: Boa comment mentions a small tool to handle this ... would be nice.
+      CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_RUSTFLAGS: ${{ (github.ref == 'refs/heads/main' || github.base_ref == 'main') && '-D warnings' || '' }}
+      CARGO_TARGET_AARCH64_APPLE_DARWIN_RUSTFLAGS: ${{ (github.ref == 'refs/heads/main' || github.base_ref == 'main') && '-D warnings' || '' }}
     strategy:
       matrix:
         rust:
@@ -86,6 +104,11 @@ jobs:
     name: Test feature matrix
     runs-on: ubuntu-latest
     steps:
+      - name: Set environment
+        run: |
+          target=$(rustc -vV | awk '/^host/ { print $2 }' | tr [:lower:] [:upper:] | tr '-' '_')
+          echo "CARGO_TARGET_${target}_RUSTFLAGS=$FLAGS" >> $GITHUB_ENV
+
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
@@ -110,6 +133,11 @@ jobs:
         os: [ubuntu-latest] # Todo: potentially add more if we add cpp tests
     runs-on: ${{ matrix.os }}
     steps:
+      - name: Set environment
+        run: |
+          target=$(rustc -vV | awk '/^host/ { print $2 }' | tr [:lower:] [:upper:] | tr '-' '_')
+          echo "CARGO_TARGET_${target}_RUSTFLAGS=$FLAGS" >> $GITHUB_ENV
+
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:

src/primitive.rs

@@ -29,7 +29,7 @@ impl FiniteF64 {
     #[inline]
     pub fn negate(&self) -> Self {
         if !self.is_zero() {
-            Self(self.0 * -1.0)
+            Self(-self.0)
         } else {
             *self
         }

src/utils.rs

@@ -28,7 +28,7 @@ pub(crate) fn epoch_days_to_epoch_ms(day: i64, time: i64) -> i64 {
 /// returns a String representation of y suitable for inclusion in an ISO 8601 string
 pub(crate) fn pad_iso_year(year: i32) -> String {
     if (0..9999).contains(&year) {
-        return format!("{:04}", year);
+        return format!("{year:04}");
     }
     let year_sign = if year > 0 { "+" } else { "-" };
     let year_string = format!("{:06}", year.abs());

tools/zoneinfo-test-gen/src/main.rs

@@ -30,7 +30,7 @@ fn generate_test_data(input_dir: PathBuf, output_dir: PathBuf, identifier: &str)
     let test_data_path = output_dir.join(format!("{filename}.json"));
 
     let tzif_path = input_dir.join(identifier);
-    std::println!("Parsing tzif from {:?}", tzif_path);
+    std::println!("Parsing tzif from {tzif_path:?}");
     let tzif = tzif::parse_tzif_file(&tzif_path).unwrap();
 
     let tzif_block_v2 = tzif.data_block2.unwrap();
@@ -71,7 +71,7 @@ fn generate_test_data(input_dir: PathBuf, output_dir: PathBuf, identifier: &str)
         transitions,
     };
 
-    std::println!("Writing generated example data to {:?}", test_data_path);
+    std::println!("Writing generated example data to {test_data_path:?}");
     fs::write(
         test_data_path,
         serde_json::to_string_pretty(&tzif_data).unwrap(),