Clean up code mostly based on clippy suggestions

crates/cargo-platform/src/lib.rs

@@ -84,16 +84,14 @@ impl Platform {
                             )),
                         _ => (),
                     },
-                    Cfg::KeyPair(name, _) => match name.as_str() {
-                        "feature" =>
-                            warnings.push(String::from(
-                                "Found `feature = ...` in `target.'cfg(...)'.dependencies`. \
-                                 This key is not supported for selecting dependencies \
-                                 and will not work as expected. \
-                                 Use the [features] section instead: \
-                                 https://doc.rust-lang.org/cargo/reference/features.html"
-                            )),
-                        _ => (),
+                    Cfg::KeyPair(name, _) => if name.as_str() == "feature" {
+                        warnings.push(String::from(
+                            "Found `feature = ...` in `target.'cfg(...)'.dependencies`. \
+                             This key is not supported for selecting dependencies \
+                             and will not work as expected. \
+                             Use the [features] section instead: \
+                             https://doc.rust-lang.org/cargo/reference/features.html"
+                        ))
                     },
                 }
             }

crates/crates-io/lib.rs

@@ -11,7 +11,6 @@ use anyhow::{bail, Result};
 use curl::easy::{Easy, List};
 use percent_encoding::{percent_encode, NON_ALPHANUMERIC};
 use serde::{Deserialize, Serialize};
-use serde_json;
 use url::Url;
 
 pub struct Registry {

src/bin/cargo/cli.rs

@@ -1,9 +1,6 @@
-use clap;
-
-use clap::{AppSettings, Arg, ArgMatches};
-
 use cargo::core::features;
 use cargo::{self, CliResult, Config};
+use clap::{AppSettings, Arg, ArgMatches};
 
 use super::commands;
 use super::list_commands;
@@ -154,7 +151,7 @@ fn expand_aliases(
                 // capture those global options now.
                 // Note that an alias to an external command will not receive
                 // these arguments. That may be confusing, but such is life.
-                let global_args = GlobalArgs::new(&args);
+                let global_args = GlobalArgs::new(args);
                 let new_args = cli()
                     .setting(AppSettings::NoBinaryName)
                     .get_matches_from_safe(alias)?;

src/cargo/core/compiler/context/compilation_files.rs

@@ -271,8 +271,7 @@ impl<'a, 'cfg: 'a> CompilationFiles<'a, 'cfg> {
 
         let file_type = file_types
             .iter()
-            .filter(|file_type| file_type.flavor == FileFlavor::Normal)
-            .next()
+            .find(|file_type| file_type.flavor == FileFlavor::Normal)
             .expect("target must support `bin`");
 
         Ok(dest.join(file_type.filename(target.name())))

src/cargo/core/compiler/unit_dependencies.rs

@@ -267,10 +267,7 @@ fn compute_deps<'a, 'cfg>(
             // If this is an optional dependency, and the new feature resolver
             // did not enable it, don't include it.
             if dep.is_optional() {
-                let features_for = match unit_for.is_for_build_dep() {
-                    true => FeaturesFor::BuildDep,
-                    false => FeaturesFor::NormalOrDev,
-                };
+                let features_for = unit_for.map_to_features_for();
 
                 let feats = state.activated_features(id, features_for);
                 if !feats.contains(&dep.name_in_toml()) {
@@ -627,10 +624,7 @@ fn new_unit_dep_with_profile<'a>(
     let public = state
         .resolve()
         .is_public_dep(parent.pkg.package_id(), pkg.package_id());
-    let features_for = match unit_for.is_for_build_dep() {
-        true => FeaturesFor::BuildDep,
-        false => FeaturesFor::NormalOrDev,
-    };
+    let features_for = unit_for.map_to_features_for();
     let features = state.activated_features(pkg.package_id(), features_for);
     let unit = state
         .bcx

src/cargo/core/package_id.rs

@@ -6,7 +6,6 @@ use std::path::Path;
 use std::ptr;
 use std::sync::Mutex;
 
-use semver;
 use serde::de;
 use serde::ser;
 

src/cargo/core/profiles.rs

@@ -1,5 +1,6 @@
 use crate::core::compiler::CompileMode;
 use crate::core::interning::InternedString;
+use crate::core::resolver::features::FeaturesFor;
 use crate::core::{Feature, Features, PackageId, PackageIdSpec, Resolve, Shell};
 use crate::util::errors::CargoResultExt;
 use crate::util::toml::{ProfilePackageSpec, StringOrBool, TomlProfile, TomlProfiles, U32OrBool};
@@ -975,6 +976,14 @@ impl UnitFor {
         ];
         ALL
     }
+
+    pub(crate) fn map_to_features_for(&self) -> FeaturesFor {
+        if self.is_for_build_dep() {
+            FeaturesFor::BuildDep
+        } else {
+            FeaturesFor::NormalOrDev
+        }
+    }
 }
 
 /// Takes the manifest profiles, and overlays the config profiles on-top.

src/cargo/core/resolver/errors.rs

@@ -4,7 +4,6 @@ use crate::core::{Dependency, PackageId, Registry, Summary};
 use crate::util::lev_distance::lev_distance;
 use crate::util::Config;
 use anyhow::Error;
-use semver;
 
 use super::context::Context;
 use super::types::{ConflictMap, ConflictReason};

src/cargo/core/resolver/resolve.rs

@@ -385,8 +385,7 @@ impl PartialEq for Resolve {
     fn eq(&self, other: &Resolve) -> bool {
         macro_rules! compare {
             ($($fields:ident)* | $($ignored:ident)*) => {
-                let Resolve { $($fields,)* $($ignored,)* } = self;
-                $(drop($ignored);)*
+                let Resolve { $($fields,)* $($ignored: _,)* } = self;
                 $($fields == &other.$fields)&&*
             }
         }

src/cargo/core/resolver/types.rs

@@ -3,7 +3,6 @@ use crate::core::interning::InternedString;
 use crate::core::{Dependency, PackageId, Summary};
 use crate::util::errors::CargoResult;
 use crate::util::Config;
-use im_rc;
 use std::cmp::Ordering;
 use std::collections::{BTreeMap, BTreeSet};
 use std::ops::Range;

src/cargo/core/shell.rs

@@ -1,7 +1,6 @@
 use std::fmt;
 use std::io::prelude::*;
 
-use atty;
 use termcolor::Color::{Cyan, Green, Red, Yellow};
 use termcolor::{self, Color, ColorSpec, StandardStream, WriteColor};
 
@@ -382,11 +381,8 @@ impl ColorChoice {
 
 #[cfg(any(target_os = "linux", target_os = "macos", target_os = "freebsd"))]
 mod imp {
-    use std::mem;
-
-    use libc;
-
     use super::Shell;
+    use std::mem;
 
     pub fn stderr_width() -> Option<usize> {
         unsafe {

src/cargo/core/workspace.rs

@@ -884,7 +884,7 @@ impl<'cfg> Workspace<'cfg> {
                     .map(|m| (m, RequestedFeatures::new_all(false)))
                     .collect());
             }
-            return Ok(members);
+            Ok(members)
         } else {
             let ms = self.members().filter_map(|member| {
                 let member_id = member.package_id();
@@ -911,7 +911,7 @@ impl<'cfg> Workspace<'cfg> {
                     }
                 }
             });
-            return Ok(ms.collect());
+            Ok(ms.collect())
         }
     }
 }

src/cargo/ops/cargo_clean.rs

@@ -7,9 +7,7 @@ use crate::core::compiler::unit_dependencies;
 use crate::core::compiler::{BuildConfig, BuildContext, CompileKind, CompileMode, Context};
 use crate::core::compiler::{RustcTargetData, UnitInterner};
 use crate::core::profiles::{Profiles, UnitFor};
-use crate::core::resolver::features::{
-    FeatureResolver, FeaturesFor, HasDevUnits, RequestedFeatures,
-};
+use crate::core::resolver::features::{FeatureResolver, HasDevUnits, RequestedFeatures};
 use crate::core::{PackageIdSpec, Workspace};
 use crate::ops;
 use crate::util::errors::{CargoResult, CargoResultExt};
@@ -120,10 +118,7 @@ pub fn clean(ws: &Workspace<'_>, opts: &CleanOptions<'_>) -> CargoResult<()> {
                         };
                         // Use unverified here since this is being more
                         // exhaustive than what is actually needed.
-                        let features_for = match unit_for.is_for_build_dep() {
-                            true => FeaturesFor::BuildDep,
-                            false => FeaturesFor::NormalOrDev,
-                        };
+                        let features_for = unit_for.map_to_features_for();
                         let features =
                             features.activated_features_unverified(pkg.package_id(), features_for);
                         units.push(bcx.units.intern(

src/cargo/ops/cargo_compile.rs

@@ -312,9 +312,10 @@ pub fn compile_ws<'a>(
     let specs = spec.to_package_id_specs(ws)?;
     let dev_deps = ws.require_optional_deps() || filter.need_dev_deps(build_config.mode);
     let opts = ResolveOpts::new(dev_deps, features, all_features, !no_default_features);
-    let has_dev_units = match filter.need_dev_deps(build_config.mode) {
-        true => HasDevUnits::Yes,
-        false => HasDevUnits::No,
+    let has_dev_units = if filter.need_dev_deps(build_config.mode) {
+        HasDevUnits::Yes
+    } else {
+        HasDevUnits::No
     };
     let resolve = ops::resolve_ws_with_opts(
         ws,
@@ -950,9 +951,10 @@ fn resolve_all_features(
     // required-features field when deciding whether to be built or skipped.
     for (dep_id, deps) in resolve_with_overrides.deps(package_id) {
         for dep in deps {
-            let features_for = match dep.is_build() {
-                true => FeaturesFor::BuildDep,
-                false => FeaturesFor::NormalOrDev,
+            let features_for = if dep.is_build() {
+                FeaturesFor::BuildDep
+            } else {
+                FeaturesFor::NormalOrDev
             };
             for feature in resolved_features.activated_features(dep_id, features_for) {
                 features.insert(dep.name_in_toml().to_string() + "/" + &feature);

src/cargo/ops/cargo_new.rs

@@ -15,8 +15,6 @@ use std::path::{Path, PathBuf};
 use std::process::Command;
 use std::str::{from_utf8, FromStr};
 
-use toml;
-
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum VersionControl {
     Git,

src/cargo/ops/cargo_output_metadata.rs

@@ -172,7 +172,7 @@ fn build_resolve_graph_r(
     if node_map.contains_key(&pkg_id) {
         return;
     }
-    let features = resolve.features(pkg_id).iter().cloned().collect();
+    let features = resolve.features(pkg_id).to_vec();
 
     let deps: Vec<Dep> = resolve
         .deps(pkg_id)

src/cargo/ops/lockfile.rs

@@ -1,7 +1,5 @@
 use std::io::prelude::*;
 
-use toml;
-
 use crate::core::{resolver, Resolve, ResolveVersion, Workspace};
 use crate::util::errors::{CargoResult, CargoResultExt};
 use crate::util::toml as cargo_toml;

src/cargo/util/config/mod.rs

@@ -576,7 +576,7 @@ impl Config {
     /// Helper for StringList type to get something that is a string or list.
     fn get_list_or_string(&self, key: &ConfigKey) -> CargoResult<Vec<(String, Definition)>> {
         let mut res = Vec::new();
-        match self.get_cv(&key)? {
+        match self.get_cv(key)? {
             Some(CV::List(val, _def)) => res.extend(val),
             Some(CV::String(val, def)) => {
                 let split_vs = val.split_whitespace().map(|s| (s.to_string(), def.clone()));

src/cargo/util/flock.rs

@@ -4,8 +4,6 @@ use std::io::{Read, Seek, SeekFrom, Write};
 use std::path::{Display, Path, PathBuf};
 
 use fs2::{lock_contended_error, FileExt};
-#[allow(unused_imports)]
-use libc;
 use termcolor::Color::Cyan;
 #[cfg(windows)]
 use winapi::shared::winerror::ERROR_INVALID_FUNCTION;

src/cargo/util/graph.rs

@@ -2,8 +2,6 @@ use std::borrow::Borrow;
 use std::collections::BTreeSet;
 use std::fmt;
 
-use im_rc;
-
 pub struct Graph<N: Clone, E: Clone> {
     nodes: im_rc::OrdMap<N, im_rc::OrdMap<N, E>>,
 }

src/cargo/util/hex.rs

@@ -1,6 +1,5 @@
 #![allow(deprecated)]
 
-use hex;
 use std::hash::{Hash, Hasher, SipHasher};
 
 pub fn to_hex(num: u64) -> String {

src/cargo/util/job.rs

@@ -23,7 +23,6 @@ pub fn setup() -> Option<Setup> {
 
 #[cfg(unix)]
 mod imp {
-    use libc;
     use std::env;
 
     pub type Setup = ();

src/cargo/util/network.rs

@@ -1,6 +1,3 @@
-use curl;
-use git2;
-
 use anyhow::Error;
 
 use crate::util::errors::{CargoResult, HttpNot200};

src/cargo/util/paths.rs

@@ -378,21 +378,19 @@ fn _link_or_copy(src: &Path, dst: &Path) -> CargoResult<()> {
             src
         };
         symlink(src, dst)
+    } else if env::var_os("__CARGO_COPY_DONT_LINK_DO_NOT_USE_THIS").is_some() {
+        // This is a work-around for a bug in macOS 10.15. When running on
+        // APFS, there seems to be a strange race condition with
+        // Gatekeeper where it will forcefully kill a process launched via
+        // `cargo run` with SIGKILL. Copying seems to avoid the problem.
+        // This shouldn't affect anyone except Cargo's test suite because
+        // it is very rare, and only seems to happen under heavy load and
+        // rapidly creating lots of executables and running them.
+        // See https://github.com/rust-lang/cargo/issues/7821 for the
+        // gory details.
+        fs::copy(src, dst).map(|_| ())
     } else {
-        if env::var_os("__CARGO_COPY_DONT_LINK_DO_NOT_USE_THIS").is_some() {
-            // This is a work-around for a bug in macOS 10.15. When running on
-            // APFS, there seems to be a strange race condition with
-            // Gatekeeper where it will forcefully kill a process launched via
-            // `cargo run` with SIGKILL. Copying seems to avoid the problem.
-            // This shouldn't affect anyone except Cargo's test suite because
-            // it is very rare, and only seems to happen under heavy load and
-            // rapidly creating lots of executables and running them.
-            // See https://github.com/rust-lang/cargo/issues/7821 for the
-            // gory details.
-            fs::copy(src, dst).map(|_| ())
-        } else {
-            fs::hard_link(src, dst)
-        }
+        fs::hard_link(src, dst)
     };
     link_result
         .or_else(|err| {

src/cargo/util/read2.rs

@@ -2,7 +2,6 @@ pub use self::imp::read2;
 
 #[cfg(unix)]
 mod imp {
-    use libc;
     use std::io;
     use std::io::prelude::*;
     use std::mem;

src/cargo/util/sha256.rs

@@ -1,6 +1,5 @@
-use self::crypto_hash::{Algorithm, Hasher};
 use crate::util::{CargoResult, CargoResultExt};
-use crypto_hash;
+use crypto_hash::{Algorithm, Hasher};
 use std::fs::File;
 use std::io::{self, Read, Write};
 use std::path::Path;

src/cargo/util/toml/mod.rs

@@ -1137,7 +1137,7 @@ impl TomlManifest {
                         .collect()
                 })
                 .unwrap_or_else(BTreeMap::new),
-            project.links.as_ref().map(|x| x.as_str()),
+            project.links.as_deref(),
             project.namespaced_features.unwrap_or(false),
         )?;
         let metadata = ManifestMetadata {

src/cargo/util/vcs.rs

@@ -1,6 +1,5 @@
 use crate::util::paths;
 use crate::util::{process, CargoResult};
-use git2;
 use std::path::Path;
 
 // Check if we are in an existing repo. We define that to be true if either: