Clippy lints

Cargo.toml

@@ -1,7 +1,10 @@
 [package]
 name = "memmap2"
 version = "0.9.5"
-authors = ["Dan Burkert <dan@danburkert.com>", "Yevhenii Reizner <razrfalcon@gmail.com>"]
+authors = [
+	"Dan Burkert <dan@danburkert.com>",
+	"Yevhenii Reizner <razrfalcon@gmail.com>",
+]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/RazrFalcon/memmap2-rs"
 documentation = "https://docs.rs/memmap2"

clippy.toml

@@ -0,0 +1 @@
+msrv = "1.36.0"

src/advice.rs

@@ -229,7 +229,7 @@ pub enum Advice {
     /// Indicates that the application would like the wired pages in this address range to be
     /// zeroed out if the address range is deallocated without first unwiring the pages (i.e.
     /// a munmap(2) without a preceding munlock(2) or the application quits).  This is used
-    /// with madvise() system call.
+    /// with `madvise()` system call.
     #[cfg(any(target_os = "macos", target_os = "ios"))]
     ZeroWiredPages = libc::MADV_ZERO_WIRED_PAGES,
 }

src/lib.rs

@@ -1,3 +1,22 @@
+#![deny(clippy::all, clippy::pedantic)]
+#![allow(
+    // pedantic exceptions
+    clippy::cast_possible_truncation,
+    clippy::cast_possible_wrap,
+    clippy::cast_sign_loss,
+    clippy::doc_markdown,
+    clippy::explicit_deref_methods,
+    clippy::missing_errors_doc,
+    clippy::module_name_repetitions,
+    clippy::must_use_candidate,
+    clippy::needless_pass_by_value,
+    clippy::return_self_not_must_use,
+    clippy::unreadable_literal,
+    clippy::upper_case_acronyms,
+    // remove later
+    clippy::legacy_numeric_constants
+)]
+
 //! A cross-platform Rust API for memory mapped buffers.
 //!
 //! The core functionality is provided by either [`Mmap`] or [`MmapMut`],
@@ -229,36 +248,39 @@ impl MmapOptions {
 
     /// Returns the configured length, or the length of the provided file.
     fn get_len<T: MmapAsRawDesc>(&self, file: &T) -> Result<usize> {
-        self.len.map(Ok).unwrap_or_else(|| {
-            let desc = file.as_raw_desc();
-            let file_len = file_len(desc.0)?;
-
-            if file_len < self.offset {
-                return Err(Error::new(
-                    ErrorKind::InvalidData,
-                    "memory map offset is larger than length",
-                ));
-            }
-            let len = file_len - self.offset;
-
-            // Rust's slice cannot be larger than isize::MAX.
-            // See https://doc.rust-lang.org/std/slice/fn.from_raw_parts.html
-            //
-            // This is not a problem on 64-bit targets, but on 32-bit one
-            // having a file or an anonymous mapping larger than 2GB is quite normal
-            // and we have to prevent it.
-            //
-            // The code below is essentially the same as in Rust's std:
-            // https://github.com/rust-lang/rust/blob/db78ab70a88a0a5e89031d7ee4eccec835dcdbde/library/alloc/src/raw_vec.rs#L495
-            if mem::size_of::<usize>() < 8 && len > isize::MAX as u64 {
-                return Err(Error::new(
-                    ErrorKind::InvalidData,
-                    "memory map length overflows isize",
-                ));
-            }
-
-            Ok(len as usize)
-        })
+        self.len.map_or_else(
+            || {
+                let desc = file.as_raw_desc();
+                let file_len = file_len(desc.0)?;
+
+                if file_len < self.offset {
+                    return Err(Error::new(
+                        ErrorKind::InvalidData,
+                        "memory map offset is larger than length",
+                    ));
+                }
+                let len = file_len - self.offset;
+
+                // Rust's slice cannot be larger than isize::MAX.
+                // See https://doc.rust-lang.org/std/slice/fn.from_raw_parts.html
+                //
+                // This is not a problem on 64-bit targets, but on 32-bit one
+                // having a file or an anonymous mapping larger than 2GB is quite normal
+                // and we have to prevent it.
+                //
+                // The code below is essentially the same as in Rust's std:
+                // https://github.com/rust-lang/rust/blob/db78ab70a88a0a5e89031d7ee4eccec835dcdbde/library/alloc/src/raw_vec.rs#L495
+                if mem::size_of::<usize>() < 8 && len > isize::MAX as u64 {
+                    return Err(Error::new(
+                        ErrorKind::InvalidData,
+                        "memory map length overflows isize",
+                    ));
+                }
+
+                Ok(len as usize)
+            },
+            Ok,
+        )
     }
 
     /// Configures the anonymous memory map to be suitable for a process or thread stack.
@@ -418,7 +440,7 @@ impl MmapOptions {
     /// # let tempdir = tempfile::tempdir()?;
     /// let path: PathBuf = /* path to file */
     /// #   tempdir.path().join("map_mut");
-    /// let file = OpenOptions::new().read(true).write(true).create(true).open(&path)?;
+    /// let file = OpenOptions::new().read(true).write(true).create(true).truncate(true).open(&path)?;
     /// file.set_len(13)?;
     ///
     /// let mut mmap = unsafe {
@@ -676,6 +698,7 @@ impl Mmap {
     /// #                      .read(true)
     /// #                      .write(true)
     /// #                      .create(true)
+    /// #                      .truncate(true)
     /// #                      .open(tempdir.path()
     /// #                      .join("make_mut"))?;
     /// # file.set_len(128)?;
@@ -886,7 +909,7 @@ impl MmapRaw {
     /// let tempdir = tempfile::tempdir()?;
     /// let path: PathBuf = /* path to file */
     /// #   tempdir.path().join("flush");
-    /// let file = OpenOptions::new().read(true).write(true).create(true).open(&path)?;
+    /// let file = OpenOptions::new().read(true).write(true).create(true).truncate(true).open(&path)?;
     /// file.set_len(128)?;
     ///
     /// let mut mmap = unsafe { MmapRaw::map_raw(&file)? };
@@ -1113,6 +1136,7 @@ impl MmapMut {
     ///                        .read(true)
     ///                        .write(true)
     ///                        .create(true)
+    ///                        .truncate(true)  
     ///                        .open(&path)?;
     /// file.set_len(13)?;
     ///
@@ -1160,7 +1184,7 @@ impl MmapMut {
     /// # let tempdir = tempfile::tempdir()?;
     /// let path: PathBuf = /* path to file */
     /// #   tempdir.path().join("flush");
-    /// let file = OpenOptions::new().read(true).write(true).create(true).open(&path)?;
+    /// let file = OpenOptions::new().read(true).write(true).create(true).truncate(true).open(&path)?;
     /// file.set_len(128)?;
     ///
     /// let mut mmap = unsafe { MmapMut::map_mut(&file)? };
@@ -1469,6 +1493,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
 
@@ -1502,6 +1527,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
 
@@ -1534,6 +1560,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
         let mmap = unsafe { Mmap::map(&file).unwrap() };
@@ -1566,7 +1593,7 @@ mod test {
 
     #[test]
     fn map_anon_zero_len() {
-        assert!(MmapOptions::new().map_anon().unwrap().is_empty())
+        assert!(MmapOptions::new().map_anon().unwrap().is_empty());
     }
 
     #[test]
@@ -1589,6 +1616,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
         file.set_len(128).unwrap();
@@ -1613,6 +1641,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
         file.set_len(128).unwrap();
@@ -1639,6 +1668,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
         file.set_len(128).unwrap();
@@ -1675,6 +1705,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
         file.set_len(128).unwrap();
@@ -1700,10 +1731,11 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
 
-        let offset = u32::MAX as u64 + 2;
+        let offset = u64::from(u32::MAX) + 2;
         let len = 5432;
         file.set_len(offset + len as u64).unwrap();
 
@@ -1743,14 +1775,13 @@ mod test {
 
     #[test]
     fn sync_send() {
-        let mmap = MmapMut::map_anon(129).unwrap();
-
         fn is_sync_send<T>(_val: T)
         where
             T: Sync + Send,
         {
         }
 
+        let mmap = MmapMut::map_anon(129).unwrap();
         is_sync_send(mmap);
     }
 
@@ -1787,6 +1818,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(tempdir.path().join("jit_x86"))
             .expect("open");
 
@@ -1807,6 +1839,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .expect("open");
         file.set_len(256_u64).expect("set_len");
@@ -1853,6 +1886,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .expect("open");
         file.set_len(256_u64).expect("set_len");
@@ -1907,6 +1941,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .expect("open");
         file.write_all(b"abc123").unwrap();
@@ -1961,6 +1996,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
 
@@ -2067,6 +2103,7 @@ mod test {
             .read(true)
             .write(true)
             .create(true)
+            .truncate(true)
             .open(path)
             .unwrap();
         file.set_len(128).unwrap();
@@ -2115,8 +2152,8 @@ mod test {
 
         unsafe {
             mmap.remap(final_len, RemapOptions::new().may_move(true))
-                .unwrap()
-        };
+                .unwrap();
+        }
 
         // The size should have been updated
         assert_eq!(mmap.len(), final_len);
@@ -2197,8 +2234,8 @@ mod test {
 
         unsafe {
             mmap.remap(final_len, RemapOptions::new().may_move(true))
-                .unwrap()
-        };
+                .unwrap();
+        }
 
         // The size should have been updated
         assert_eq!(mmap.len(), final_len);

src/unix.rs

@@ -288,9 +288,9 @@ impl MmapInner {
         let stack = if stack { MAP_STACK } else { 0 };
         let populate = if populate { MAP_POPULATE } else { 0 };
         let hugetlb = if huge.is_some() { MAP_HUGETLB } else { 0 };
-        let offset = huge
-            .map(|mask| ((mask as u64) & (MAP_HUGE_MASK as u64)) << MAP_HUGE_SHIFT)
-            .unwrap_or(0);
+        let offset = huge.map_or(0, |mask| {
+            (u64::from(mask) & (MAP_HUGE_MASK as u64)) << MAP_HUGE_SHIFT
+        });
         MmapInner::new(
             len,
             libc::PROT_READ | libc::PROT_WRITE,

src/windows.rs

@@ -77,6 +77,7 @@ struct SYSTEM_INFO {
     wProcessorRevision: WORD,
 }
 
+#[allow(dead_code)]
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub struct FILETIME {
@@ -136,8 +137,7 @@ extern "system" {
 ///
 /// This aligns the pointer to `allocation_granularity()` or 1 if unknown.
 fn empty_slice_ptr() -> *mut c_void {
-    let align = allocation_granularity().max(1);
-    unsafe { mem::transmute(align) }
+    allocation_granularity().max(1) as *mut c_void
 }
 
 pub struct MmapInner {
@@ -216,7 +216,7 @@ impl MmapInner {
             Ok(MmapInner {
                 handle: Some(new_handle),
                 ptr: ptr.offset(alignment as isize),
-                len: len as usize,
+                len,
                 copy,
             })
         }
@@ -382,7 +382,7 @@ impl MmapInner {
                 Ok(MmapInner {
                     handle: None,
                     ptr,
-                    len: len as usize,
+                    len,
                     copy: false,
                 })
             } else {
@@ -463,7 +463,7 @@ impl MmapInner {
 
     #[inline]
     pub fn mut_ptr(&mut self) -> *mut u8 {
-        self.ptr as *mut u8
+        self.ptr.cast()
     }
 
     #[inline]