Fixed clippy defects (#827)

cargo/cargo_build_script_runner/bin.rs

@@ -50,10 +50,8 @@ fn run_buildrs() -> Result<(), String> {
 
     let out_dir_abs = exec_root.join(&out_dir);
     // For some reason Google's RBE does not create the output directory, force create it.
-    create_dir_all(&out_dir_abs).expect(&format!(
-        "Failed to make output directory: {:?}",
-        out_dir_abs
-    ));
+    create_dir_all(&out_dir_abs)
+        .unwrap_or_else(|_| panic!("Failed to make output directory: {:?}", out_dir_abs));
 
     let target_env_vars =
         get_target_env_vars(&rustc_env).expect("Error getting target env vars from rustc");
@@ -119,47 +117,52 @@ fn run_buildrs() -> Result<(), String> {
         }
     }
 
-    let (buildrs_outputs, process_output) =
-        BuildScriptOutput::from_command(&mut command).map_err(|process_output| {
-            format!(
-                "Build script process failed{}\n--stdout:\n{}\n--stderr:\n{}",
-                if let Some(exit_code) = process_output.status.code() {
-                    format!(" with exit code {}", exit_code)
-                } else {
-                    String::new()
-                },
-                String::from_utf8(process_output.stdout)
-                    .expect("Failed to parse stdout of child process"),
-                String::from_utf8(process_output.stderr)
-                    .expect("Failed to parse stdout of child process"),
-            )
-        })?;
+    let (buildrs_outputs, process_output) = BuildScriptOutput::outputs_from_command(&mut command)
+        .map_err(|process_output| {
+        format!(
+            "Build script process failed{}\n--stdout:\n{}\n--stderr:\n{}",
+            if let Some(exit_code) = process_output.status.code() {
+                format!(" with exit code {}", exit_code)
+            } else {
+                String::new()
+            },
+            String::from_utf8(process_output.stdout)
+                .expect("Failed to parse stdout of child process"),
+            String::from_utf8(process_output.stderr)
+                .expect("Failed to parse stdout of child process"),
+        )
+    })?;
 
     write(
         &env_file,
-        BuildScriptOutput::to_env(&buildrs_outputs, &exec_root.to_string_lossy()).as_bytes(),
+        BuildScriptOutput::outputs_to_env(&buildrs_outputs, &exec_root.to_string_lossy())
+            .as_bytes(),
     )
-    .expect(&format!("Unable to write file {:?}", env_file));
+    .unwrap_or_else(|_| panic!("Unable to write file {:?}", env_file));
     write(
         &output_dep_env_path,
-        BuildScriptOutput::to_dep_env(&buildrs_outputs, &crate_links, &exec_root.to_string_lossy())
-            .as_bytes(),
+        BuildScriptOutput::outputs_to_dep_env(
+            &buildrs_outputs,
+            &crate_links,
+            &exec_root.to_string_lossy(),
+        )
+        .as_bytes(),
     )
-    .expect(&format!("Unable to write file {:?}", output_dep_env_path));
+    .unwrap_or_else(|_| panic!("Unable to write file {:?}", output_dep_env_path));
     write(&stdout_path, process_output.stdout)
-        .expect(&format!("Unable to write file {:?}", stdout_path));
+        .unwrap_or_else(|_| panic!("Unable to write file {:?}", stdout_path));
     write(&stderr_path, process_output.stderr)
-        .expect(&format!("Unable to write file {:?}", stderr_path));
+        .unwrap_or_else(|_| panic!("Unable to write file {:?}", stderr_path));
 
     let CompileAndLinkFlags {
         compile_flags,
         link_flags,
-    } = BuildScriptOutput::to_flags(&buildrs_outputs, &exec_root.to_string_lossy());
+    } = BuildScriptOutput::outputs_to_flags(&buildrs_outputs, &exec_root.to_string_lossy());
 
     write(&compile_flags_file, compile_flags.as_bytes())
-        .expect(&format!("Unable to write file {:?}", compile_flags_file));
+        .unwrap_or_else(|_| panic!("Unable to write file {:?}", compile_flags_file));
     write(&link_flags_file, link_flags.as_bytes())
-        .expect(&format!("Unable to write file {:?}", link_flags_file));
+        .unwrap_or_else(|_| panic!("Unable to write file {:?}", link_flags_file));
     Ok(())
 }
 
@@ -243,7 +246,7 @@ fn get_target_env_vars<P: AsRef<Path>>(rustc: &P) -> Result<BTreeMap<String, Str
             if value.starts_with('"') && value.ends_with('"') && value.len() >= 2 {
                 values
                     .entry(key)
-                    .or_insert(vec![])
+                    .or_insert_with(Vec::new)
                     .push(value[1..(value.len() - 1)].to_owned());
             }
         }

cargo/cargo_build_script_runner/lib.rs

@@ -94,7 +94,7 @@ impl BuildScriptOutput {
     }
 
     /// Converts a [BufReader] into a vector of [BuildScriptOutput] enums.
-    fn from_reader<T: Read>(mut reader: BufReader<T>) -> Vec<BuildScriptOutput> {
+    fn outputs_from_reader<T: Read>(mut reader: BufReader<T>) -> Vec<BuildScriptOutput> {
         let mut result = Vec::<BuildScriptOutput>::new();
         let mut line = String::new();
         while reader.read_line(&mut line).expect("Cannot read line") != 0 {
@@ -107,20 +107,23 @@ impl BuildScriptOutput {
     }
 
     /// Take a [Command], execute it and converts its input into a vector of [BuildScriptOutput]
-    pub fn from_command(cmd: &mut Command) -> Result<(Vec<BuildScriptOutput>, Output), Output> {
+    pub fn outputs_from_command(
+        cmd: &mut Command,
+    ) -> Result<(Vec<BuildScriptOutput>, Output), Output> {
         let child_output = cmd.output().expect("Unable to start binary");
         if child_output.status.success() {
             let reader = BufReader::new(child_output.stdout.as_slice());
-            let output = Self::from_reader(reader);
+            let output = Self::outputs_from_reader(reader);
             Ok((output, child_output))
         } else {
             Err(child_output)
         }
     }
 
     /// Convert a vector of [BuildScriptOutput] into a list of environment variables.
-    pub fn to_env(v: &Vec<BuildScriptOutput>, exec_root: &str) -> String {
-        v.iter()
+    pub fn outputs_to_env(outputs: &[BuildScriptOutput], exec_root: &str) -> String {
+        outputs
+            .iter()
             .filter_map(|x| {
                 if let BuildScriptOutput::Env(env) = x {
                     Some(Self::escape_for_serializing(Self::redact_exec_root(
@@ -135,9 +138,14 @@ impl BuildScriptOutput {
     }
 
     /// Convert a vector of [BuildScriptOutput] into a list of dependencies environment variables.
-    pub fn to_dep_env(v: &Vec<BuildScriptOutput>, crate_links: &str, exec_root: &str) -> String {
+    pub fn outputs_to_dep_env(
+        outputs: &[BuildScriptOutput],
+        crate_links: &str,
+        exec_root: &str,
+    ) -> String {
         let prefix = format!("DEP_{}_", crate_links.replace("-", "_").to_uppercase());
-        v.iter()
+        outputs
+            .iter()
             .filter_map(|x| {
                 if let BuildScriptOutput::DepEnv(env) = x {
                     Some(format!(
@@ -154,11 +162,11 @@ impl BuildScriptOutput {
     }
 
     /// Convert a vector of [BuildScriptOutput] into a flagfile.
-    pub fn to_flags(v: &Vec<BuildScriptOutput>, exec_root: &str) -> CompileAndLinkFlags {
+    pub fn outputs_to_flags(outputs: &[BuildScriptOutput], exec_root: &str) -> CompileAndLinkFlags {
         let mut compile_flags = Vec::new();
         let mut link_flags = Vec::new();
 
-        for flag in v {
+        for flag in outputs {
             match flag {
                 BuildScriptOutput::Cfg(e) => compile_flags.push(format!("--cfg={}", e)),
                 BuildScriptOutput::Flags(e) => compile_flags.push(e.to_owned()),
@@ -214,7 +222,7 @@ cargo:rustc-env=SOME_PATH=/some/absolute/path/beep
 ",
         );
         let reader = BufReader::new(buff);
-        let result = BuildScriptOutput::from_reader(reader);
+        let result = BuildScriptOutput::outputs_from_reader(reader);
         assert_eq!(result.len(), 10);
         assert_eq!(result[0], BuildScriptOutput::LinkLib("sdfsdf".to_owned()));
         assert_eq!(result[1], BuildScriptOutput::Env("FOO=BAR".to_owned()));
@@ -242,15 +250,15 @@ cargo:rustc-env=SOME_PATH=/some/absolute/path/beep
         );
 
         assert_eq!(
-            BuildScriptOutput::to_dep_env(&result, "ssh2", "/some/absolute/path"),
+            BuildScriptOutput::outputs_to_dep_env(&result, "ssh2", "/some/absolute/path"),
             "DEP_SSH2_VERSION=123\nDEP_SSH2_VERSION_NUMBER=1010107f\nDEP_SSH2_INCLUDE_PATH=${pwd}/include".to_owned()
         );
         assert_eq!(
-            BuildScriptOutput::to_env(&result, "/some/absolute/path"),
+            BuildScriptOutput::outputs_to_env(&result, "/some/absolute/path"),
             "FOO=BAR\nBAR=FOO\nSOME_PATH=${pwd}/beep".to_owned()
         );
         assert_eq!(
-            BuildScriptOutput::to_flags(&result, "/some/absolute/path"),
+            BuildScriptOutput::outputs_to_flags(&result, "/some/absolute/path"),
             CompileAndLinkFlags {
                 // -Lblah was output as a rustc-flags, so even though it probably _should_ be a link
                 // flag, we don't treat it like one.

proto/optional_output_wrapper.rs

@@ -26,7 +26,7 @@ fn ensure() -> Result<i32, Box<dyn error::Error>> {
     let optional_outputs = args().take(index).collect::<Vec<String>>();
     let exe = args().nth(index + 1).ok_or("no exe")?;
     let exe_args = args().skip(index + 2).collect::<Vec<String>>();
-    if exe_args.len() < 1 {
+    if exe_args.is_empty() {
         return Err("no exe args".into());
     }
     match Command::new(exe).args(exe_args).status()?.code() {

test/chained_direct_deps/mod3.rs

@@ -25,7 +25,7 @@ pub fn greet_default() {
 /// );
 /// ```
 pub fn am_i_the_world(me: &str) -> bool {
-    return me == mod1::world();
+    me == mod1::world()
 }
 
 #[cfg(test)]

test/renamed_deps/mod3.rs

@@ -25,7 +25,7 @@ pub fn greet_default() {
 /// );
 /// ```
 pub fn am_i_the_world(me: &str) -> bool {
-    return me == alias_a::world();
+    me == alias_a::world()
 }
 
 #[cfg(test)]

test/rust_analyzer/aspect_traversal_test/rust_project_json_test.rs

@@ -9,7 +9,7 @@ mod tests {
             r.rlocation("rules_rust/test/rust_analyzer/aspect_traversal_test/rust-project.json");
 
         let content = std::fs::read_to_string(&rust_project_path)
-            .expect(&format!("couldn't open {:?}", &rust_project_path));
+            .unwrap_or_else(|_| panic!("couldn't open {:?}", &rust_project_path));
 
         for dep in &[
             "lib_dep",

test/rust_analyzer/merging_crates_test/rust_project_json_test.rs

@@ -9,7 +9,7 @@ mod tests {
             r.rlocation("rules_rust/test/rust_analyzer/merging_crates_test/rust-project.json");
 
         let content = std::fs::read_to_string(&rust_project_path)
-            .expect(&format!("couldn't open {:?}", &rust_project_path));
+            .unwrap_or_else(|_| panic!("couldn't open {:?}", &rust_project_path));
 
         assert!(
             content.contains(r#""root_module":"test/rust_analyzer/merging_crates_test/mylib.rs","deps":[{"crate":0,"name":"lib_dep"},{"crate":2,"name":"extra_test_dep"}]"#),

test/rust_analyzer/merging_crates_test_reversed/rust_project_json_test.rs

@@ -10,7 +10,7 @@ mod tests {
         );
 
         let content = std::fs::read_to_string(&rust_project_path)
-            .expect(&format!("couldn't open {:?}", &rust_project_path));
+            .unwrap_or_else(|_| panic!("couldn't open {:?}", &rust_project_path));
 
         assert!(
             content.contains(r#""root_module":"test/rust_analyzer/merging_crates_test_reversed/mylib.rs","deps":[{"crate":0,"name":"lib_dep"},{"crate":1,"name":"extra_test_dep"}]"#),

tools/runfiles/runfiles.rs

@@ -97,10 +97,9 @@ impl Runfiles {
             Mode::DirectoryBased(runfiles_dir) => runfiles_dir.join(path),
             Mode::ManifestBased(path_mapping) => path_mapping
                 .get(path)
-                .expect(&format!(
-                    "Path {} not found among runfiles.",
-                    path.to_string_lossy()
-                ))
+                .unwrap_or_else(|| {
+                    panic!("Path {} not found among runfiles.", path.to_string_lossy())
+                })
                 .clone(),
         }
     }
@@ -109,10 +108,11 @@ impl Runfiles {
 /// Returns the .runfiles directory for the currently executing binary.
 pub fn find_runfiles_dir() -> io::Result<PathBuf> {
     assert_ne!(
-        std::env::var_os("RUNFILES_MANIFEST_ONLY").unwrap_or(OsString::from("0")),
+        std::env::var_os("RUNFILES_MANIFEST_ONLY").unwrap_or_else(|| OsString::from("0")),
         "1"
     );
-    let exec_path = std::env::args().nth(0).expect("arg 0 was not set");
+    // Consume the first argument (argv[0])
+    let exec_path = std::env::args().next().expect("arg 0 was not set");
 
     let mut binary_path = PathBuf::from(&exec_path);
     loop {

tools/rustfmt/srcs/lib.rs

@@ -3,7 +3,7 @@ use std::fs;
 use std::path::{Path, PathBuf};
 
 /// The expected extension of rustfmt manifest files generated by `rustfmt_aspect`.
-pub const RUSTFMT_MANIFEST_EXTENSION: &'static str = "rustfmt";
+pub const RUSTFMT_MANIFEST_EXTENSION: &str = "rustfmt";
 
 /// Generate an absolute path to a file without resolving symlinks
 fn absolutify_existing<T: AsRef<Path>>(path: &T) -> std::io::Result<PathBuf> {
@@ -50,13 +50,11 @@ pub struct RustfmtManifest {
 
 /// Parse rustfmt flags from a manifest generated by builds using `rustfmt_aspect`.
 pub fn parse_rustfmt_manifest(manifest: &Path) -> RustfmtManifest {
-    let content = fs::read_to_string(manifest).expect(&format!(
-        "Failed to read rustfmt manifest: {}",
-        manifest.display()
-    ));
+    let content = fs::read_to_string(manifest)
+        .unwrap_or_else(|_| panic!("Failed to read rustfmt manifest: {}", manifest.display()));
 
     let mut lines: Vec<String> = content
-        .split("\n")
+        .split('\n')
         .into_iter()
         .filter(|s| !s.is_empty())
         .map(|s| s.to_owned())
@@ -70,7 +68,7 @@ pub fn parse_rustfmt_manifest(manifest: &Path) -> RustfmtManifest {
         .expect("The edition should be a numeric value. eg `2018`.");
 
     RustfmtManifest {
-        edition: edition,
+        edition,
         sources: lines,
     }
 }

tools/rustfmt/srcs/test_main.rs

@@ -2,9 +2,6 @@ use std::fs;
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
-use runfiles;
-use rustfmt_lib;
-
 fn main() {
     // Gather all and environment settings
     let options = parse_args();