chore: fix clippy lints/cargo warnings

The main one I am not sure about is the change of the ffi calling
convension in the windows code. According to rust-lang#137018, "stdcall"
is only for 32bit targets, which we do not support, and everything else
should just use "C".

There are some more fixes than what the CI complains about, because the
CI does not run clippy on the windows target, but my local setup does,
so I fixed up some additional warnings.

Signed-off-by: Patrick Roy <patrick.roy@linux.dev>

Author: roypat

src/mmap/unix.rs

@@ -395,7 +395,7 @@ impl<B: Bitmap> VolatileMemory for MmapRegion<B> {
         &self,
         offset: usize,
         count: usize,
-    ) -> volatile_memory::Result<VolatileSlice<BS<B>>> {
+    ) -> volatile_memory::Result<VolatileSlice<'_, BS<'_, B>>> {
         let _ = self.compute_end_offset(offset, count)?;
 
         Ok(

src/mmap/windows.rs

@@ -18,7 +18,7 @@ use crate::volatile_memory::{self, compute_offset, VolatileMemory, VolatileSlice
 
 #[allow(non_snake_case)]
 #[link(name = "kernel32")]
-extern "stdcall" {
+extern "C" {
     pub fn VirtualAlloc(
         lpAddress: *mut c_void,
         dwSize: size_t,
@@ -55,7 +55,7 @@ const MEM_RELEASE: u32 = 0x00008000;
 const FILE_MAP_ALL_ACCESS: u32 = 0xf001f;
 const PAGE_READWRITE: u32 = 0x04;
 
-pub const MAP_FAILED: *mut c_void = 0 as *mut c_void;
+pub const MAP_FAILED: *mut c_void = null_mut::<c_void>();
 pub const INVALID_HANDLE_VALUE: RawHandle = (-1isize) as RawHandle;
 #[allow(dead_code)]
 pub const ERROR_INVALID_PARAMETER: i32 = 87;
@@ -95,7 +95,7 @@ impl<B: NewBitmap> MmapRegion<B> {
         }
         // This is safe because we are creating an anonymous mapping in a place not already used by
         // any other area in this process.
-        let addr = unsafe { VirtualAlloc(0 as *mut c_void, size, MEM_COMMIT, PAGE_READWRITE) };
+        let addr = unsafe { VirtualAlloc(null_mut::<c_void>(), size, MEM_COMMIT, PAGE_READWRITE) };
         if addr == MAP_FAILED {
             return Err(io::Error::last_os_error());
         }
@@ -111,7 +111,7 @@ impl<B: NewBitmap> MmapRegion<B> {
     ///
     /// # Arguments
     /// * `file_offset` - The mapping will be created at offset `file_offset.start` in the file
-    ///                   referred to by `file_offset.file`.
+    ///   referred to by `file_offset.file`.
     /// * `size` - The size of the memory region in bytes.
     pub fn from_file(file_offset: FileOffset, size: usize) -> io::Result<Self> {
         let handle = file_offset.file().as_raw_handle();
@@ -151,7 +151,7 @@ impl<B: NewBitmap> MmapRegion<B> {
             CloseHandle(mapping);
         }
 
-        if addr == null_mut() {
+        if addr.is_null() {
             return Err(io::Error::last_os_error());
         }
         Ok(Self {
@@ -200,7 +200,7 @@ impl<B: Bitmap> VolatileMemory for MmapRegion<B> {
         &self,
         offset: usize,
         count: usize,
-    ) -> volatile_memory::Result<VolatileSlice<BS<Self::B>>> {
+    ) -> volatile_memory::Result<VolatileSlice<'_, BS<'_, Self::B>>> {
         let end = compute_offset(offset, count)?;
         if end > self.size {
             return Err(volatile_memory::Error::OutOfBounds { addr: end });