Merge #1374

1374: Implement `cargo lint` and fix some clippy errors r=alanhdu a=alanhdu

This creates a `cargo lint` command that runs clippy with certain lints disabled. I've also gone ahead and fixed some of the lint errors, although there are many more still to go.

cc #848 

Co-authored-by: Alan Du <[email protected]>

2 files changed, 38 insertions, 2 deletions

diff --git a/crates/tools/src/lib.rs b/crates/tools/src/lib.rs
index 11b52ccb7..2446fdf28 100644
--- a/crates/tools/src/lib.rs
+++ b/crates/tools/src/lib.rs
@@ -133,6 +133,40 @@ pub fn install_format_hook() -> Result<()> {
     Ok(())
 }
 
+pub fn run_clippy() -> Result<()> {
+    match Command::new("rustup")
+        .args(&["run", TOOLCHAIN, "--", "cargo", "clippy", "--version"])
+        .stderr(Stdio::null())
+        .stdout(Stdio::null())
+        .status()
+    {
+        Ok(status) if status.success() => (),
+        _ => install_clippy()?,
+    };
+
+    let allowed_lints = [
+        "clippy::collapsible_if",
+        "clippy::map_clone", // FIXME: remove when Iterator::copied stabilizes (1.36.0)
+        "clippy::needless_pass_by_value",
+        "clippy::nonminimal_bool",
+        "clippy::redundant_pattern_matching",
+    ];
+    run(
+        &format!(
+            "rustup run {} -- cargo clippy --all-features --all-targets -- -A {}",
+            TOOLCHAIN,
+            allowed_lints.join(" -A ")
+        ),
+        ".",
+    )?;
+    Ok(())
+}
+
+pub fn install_clippy() -> Result<()> {
+    run(&format!("rustup install {}", TOOLCHAIN), ".")?;
+    run(&format!("rustup component add clippy --toolchain {}", TOOLCHAIN), ".")
+}
+
 pub fn run_fuzzer() -> Result<()> {
     match Command::new("cargo")
         .args(&["fuzz", "--help"])
diff --git a/crates/tools/src/main.rs b/crates/tools/src/main.rs
index 0c3339685..8027ff833 100644
--- a/crates/tools/src/main.rs
+++ b/crates/tools/src/main.rs
@@ -3,7 +3,7 @@ use core::str;
 use failure::bail;
 use tools::{
     generate, gen_tests, install_format_hook, run, run_with_output, run_rustfmt,
-    Overwrite, Result, run_fuzzer,
+    Overwrite, Result, run_fuzzer, run_clippy,
 };
 use std::{path::{PathBuf}, env};
 
@@ -16,6 +16,7 @@ fn main() -> Result<()> {
         .subcommand(SubCommand::with_name("format"))
         .subcommand(SubCommand::with_name("format-hook"))
         .subcommand(SubCommand::with_name("fuzz-tests"))
+        .subcommand(SubCommand::with_name("lint"))
         .get_matches();
     match matches.subcommand_name().expect("Subcommand must be specified") {
         "install-code" => {
@@ -28,6 +29,7 @@ fn main() -> Result<()> {
         "gen-syntax" => generate(Overwrite)?,
         "format" => run_rustfmt(Overwrite)?,
         "format-hook" => install_format_hook()?,
+        "lint" => run_clippy()?,
         "fuzz-tests" => run_fuzzer()?,
         _ => unreachable!(),
     }
@@ -82,7 +84,7 @@ fn fix_path_for_mac() -> Result<()> {
 
         [ROOT_DIR, &home_dir]
             .iter()
-            .map(|dir| String::from(dir.clone()) + COMMON_APP_PATH)
+            .map(|dir| String::from(*dir) + COMMON_APP_PATH)
             .map(PathBuf::from)
             .filter(|path| path.exists())
             .collect()