Apply some of the cargo clippy suggestions

Author: nyurik

build.rs

@@ -5,9 +5,8 @@ use std::path::Path;
 
 // Must be public so the build script of `std` can call it.
 pub fn main() {
-    match env::var("CARGO_CFG_TARGET_OS").unwrap_or_default().as_str() {
-        "android" => build_android(),
-        _ => {}
+    if env::var("CARGO_CFG_TARGET_OS").unwrap_or_default().as_str() == "android" {
+        build_android()
     }
 }
 

src/capture.rs

@@ -351,9 +351,10 @@ impl From<crate::Frame> for BacktraceFrame {
     }
 }
 
-// we don't want implementing `impl From<Backtrace> for Vec<BacktraceFrame>` on purpose,
+// we don't want to implement `impl From<Backtrace> for Vec<BacktraceFrame>` on purpose,
 // because "... additional directions for Vec<T> can weaken type inference ..."
 // more information on https://github.com/rust-lang/backtrace-rs/pull/526
+#[allow(clippy::from_over_into)]
 impl Into<Vec<BacktraceFrame>> for Backtrace {
     fn into(self) -> Vec<BacktraceFrame> {
         self.frames
@@ -452,7 +453,7 @@ impl BacktraceSymbol {
     /// This function requires the `std` feature of the `backtrace` crate to be
     /// enabled, and the `std` feature is enabled by default.
     pub fn filename(&self) -> Option<&Path> {
-        self.filename.as_ref().map(|p| &**p)
+        self.filename.as_deref()
     }
 
     /// Same as `Symbol::lineno`

src/lib.rs

@@ -18,26 +18,24 @@
 //! Next:
 //!
 //! ```
-//! fn main() {
 //! # // Unsafe here so test passes on no_std.
 //! # #[cfg(feature = "std")] {
-//!     backtrace::trace(|frame| {
-//!         let ip = frame.ip();
-//!         let symbol_address = frame.symbol_address();
-//!
-//!         // Resolve this instruction pointer to a symbol name
-//!         backtrace::resolve_frame(frame, |symbol| {
-//!             if let Some(name) = symbol.name() {
-//!                 // ...
-//!             }
-//!             if let Some(filename) = symbol.filename() {
-//!                 // ...
-//!             }
-//!         });
-//!
-//!         true // keep going to the next frame
+//! backtrace::trace(|frame| {
+//!     let ip = frame.ip();
+//!     let symbol_address = frame.symbol_address();
+//!
+//!     // Resolve this instruction pointer to a symbol name
+//!     backtrace::resolve_frame(frame, |symbol| {
+//!         if let Some(name) = symbol.name() {
+//!             // ...
+//!         }
+//!         if let Some(filename) = symbol.filename() {
+//!             // ...
+//!         }
 //!     });
-//! }
+//!
+//!     true // keep going to the next frame
+//! });
 //! # }
 //! ```
 //!

src/print.rs

@@ -289,7 +289,7 @@ impl BacktraceFrameFmt<'_, '_, '_> {
             write!(self.fmt.fmt, ":{colno}")?;
         }
 
-        write!(self.fmt.fmt, "\n")?;
+        writeln!(self.fmt.fmt)?;
         Ok(())
     }
 

src/symbolize/gimli.rs

@@ -12,7 +12,6 @@ use super::SymbolName;
 use addr2line::gimli;
 use core::convert::TryInto;
 use core::mem;
-use core::u32;
 use libc::c_void;
 use mystd::ffi::OsString;
 use mystd::fs::File;
@@ -100,7 +99,7 @@ impl Mapping {
             // only borrow `map` and `stash` and we're preserving them below.
             cx: unsafe { core::mem::transmute::<Context<'_>, Context<'static>>(cx) },
             _map: data,
-            stash: stash,
+            stash,
         })
     }
 }
@@ -122,13 +121,11 @@ impl<'data> Context<'data> {
             if cfg!(not(target_os = "aix")) {
                 let data = object.section(stash, id.name()).unwrap_or(&[]);
                 Ok(EndianSlice::new(data, Endian))
+            } else if let Some(name) = id.xcoff_name() {
+                let data = object.section(stash, name).unwrap_or(&[]);
+                Ok(EndianSlice::new(data, Endian))
             } else {
-                if let Some(name) = id.xcoff_name() {
-                    let data = object.section(stash, name).unwrap_or(&[]);
-                    Ok(EndianSlice::new(data, Endian))
-                } else {
-                    Ok(EndianSlice::new(&[], Endian))
-                }
+                Ok(EndianSlice::new(&[], Endian))
             }
         })
         .ok()?;
@@ -336,7 +333,7 @@ impl Cache {
         // never happen, and symbolicating backtraces would be ssssllllooooowwww.
         static mut MAPPINGS_CACHE: Option<Cache> = None;
 
-        f(MAPPINGS_CACHE.get_or_insert_with(|| Cache::new()))
+        f(MAPPINGS_CACHE.get_or_insert_with(Cache::new))
     }
 
     fn avma_to_svma(&self, addr: *const u8) -> Option<(usize, *const u8)> {

src/symbolize/gimli/elf.rs

@@ -21,7 +21,7 @@ impl Mapping {
     pub fn new(path: &Path) -> Option<Mapping> {
         let map = super::mmap(path)?;
         Mapping::mk_or_other(map, |map, stash| {
-            let object = Object::parse(&map)?;
+            let object = Object::parse(map)?;
 
             // Try to locate an external debug file using the build ID.
             if let Some(path_debug) = object.build_id().and_then(locate_build_id) {
@@ -47,7 +47,7 @@ impl Mapping {
     fn new_debug(original_path: &Path, path: PathBuf, crc: Option<u32>) -> Option<Mapping> {
         let map = super::mmap(&path)?;
         Mapping::mk(map, |map, stash| {
-            let object = Object::parse(&map)?;
+            let object = Object::parse(map)?;
 
             if let Some(_crc) = crc {
                 // TODO: check crc
@@ -129,6 +129,7 @@ impl<'a> Object<'a> {
         }
         let strings = syms.strings();
 
+        #[allow(clippy::useless_conversion)]
         let mut syms = syms
             .iter()
             // Only look at function/object symbols. This mirrors what
@@ -171,6 +172,7 @@ impl<'a> Object<'a> {
 
             // Check for DWARF-standard (gABI) compression, i.e., as generated
             // by ld's `--compress-debug-sections=zlib-gabi` flag.
+            #[allow(clippy::useless_conversion)]
             let flags: u64 = section.sh_flags(self.endian).into();
             if (flags & u64::from(SHF_COMPRESSED)) == 0 {
                 // Not compressed.
@@ -224,7 +226,7 @@ impl<'a> Object<'a> {
             .map(|(_index, section)| section)
     }
 
-    pub fn search_symtab<'b>(&'b self, addr: u64) -> Option<&'b [u8]> {
+    pub fn search_symtab(&self, addr: u64) -> Option<&[u8]> {
         // Same sort of binary search as Windows above
         let i = match self.syms.binary_search_by_key(&addr, |sym| sym.address) {
             Ok(i) => i,

src/symbolize/gimli/libs_dl_iterate_phdr.rs

@@ -14,7 +14,7 @@ pub(super) fn native_libraries() -> Vec<Library> {
     unsafe {
         libc::dl_iterate_phdr(Some(callback), core::ptr::addr_of_mut!(ret).cast());
     }
-    return ret;
+    ret
 }
 
 fn infer_current_exe(base_addr: usize) -> OsString {
@@ -65,8 +65,8 @@ unsafe extern "C" fn callback(
         segments: headers
             .iter()
             .map(|header| LibrarySegment {
-                len: (*header).p_memsz as usize,
-                stated_virtual_memory_address: (*header).p_vaddr as usize,
+                len: header.p_memsz as usize,
+                stated_virtual_memory_address: header.p_vaddr as usize,
             })
             .collect(),
         bias: info.dlpi_addr as usize,

src/symbolize/mod.rs

@@ -63,7 +63,7 @@ pub fn resolve<F: FnMut(&Symbol)>(addr: *mut c_void, cb: F) {
     unsafe { resolve_unsynchronized(addr, cb) }
 }
 
-/// Resolve a previously capture frame to a symbol, passing the symbol to the
+/// Resolve a previously captured frame to a symbol, passing the symbol to the
 /// specified closure.
 ///
 /// This function performs the same function as `resolve` except that it takes a
@@ -346,7 +346,7 @@ fn format_symbol_name(
     mut bytes: &[u8],
     f: &mut fmt::Formatter<'_>,
 ) -> fmt::Result {
-    while bytes.len() > 0 {
+    while !bytes.is_empty() {
         match str::from_utf8(bytes) {
             Ok(name) => {
                 fmt(name, f)?;

src/types.rs

@@ -33,9 +33,9 @@ impl<'a> BytesOrWideString<'a> {
     pub fn to_str_lossy(&self) -> Cow<'a, str> {
         use self::BytesOrWideString::*;
 
-        match self {
-            &Bytes(slice) => String::from_utf8_lossy(slice),
-            &Wide(wide) => Cow::Owned(String::from_utf16_lossy(wide)),
+        match *self {
+            Bytes(slice) => String::from_utf8_lossy(slice),
+            Wide(wide) => Cow::Owned(String::from_utf16_lossy(wide)),
         }
     }