Use clippy (#276)

* cton-util: fix some clippy unnecessary pass-by-value warnings

* clippy: ignore too many arguments / cyclomatic complexity in module

since these functions are taking args coming from the command line, i
dont think this is actually a valid lint, morally the arguments are all
from one structure

* cton-util: take care of remaining clippy warnings

* cton-reader: fix all non-suspicious clippy warnings

* cton-reader: disable clippy at site of suspicious lint

* cton-frontend: disable clippy at the site of an invalid lint

* cton-frontend: fix clippy warnings, or ignore benign ones

* clippy: ignore the camelcase word WebAssembly in docs

* cton-wasm: fix clippy complaints or ignore benign ones

* cton-wasm tests: fix clippy complaints

* cretonne: starting point turns off all clippy warnings

* cretonne: clippy fixes, or lower allow() to source of problem

* cretonne: more clippy fixes

* cretonne: fix or disable needless_lifetimes lint

this linter is buggy when the declared lifetime is used for another type
constraint.

* cretonne: fix clippy complaint about Pass::NoPass

* rustfmt

* fix prev minor api changes clippy suggested

* add clippy to test-all

* cton-filetests: clippy fixes

* simplify clippy reporting in test-all

* cretonne: document clippy allows better

* cretonne: fix some more clippy lints

* cretonne: fix clippy lints (mostly doc comments)

* cretonne: allow all needless_lifetimes clippy warnings

remove overrides at the false positives

* rustfmt

lib/filetests/src/concurrent.rs

@@ -70,7 +70,7 @@ impl ConcurrentRunner {
         assert!(self.request_tx.is_none(), "must shutdown before join");
         for h in self.handles.drain(..) {
             match h.join() {
-                Ok(t) => timing::add_to_current(t),
+                Ok(t) => timing::add_to_current(&t),
                 Err(e) => println!("worker panicked: {:?}", e),
             }
         }

lib/filetests/src/lib.rs

@@ -3,6 +3,11 @@
 //! This crate contains the main test driver as well as implementations of the
 //! available filetest commands.
 
+#![cfg_attr(feature="cargo-clippy", allow(
+        type_complexity,
+// Rustfmt 0.9.0 is at odds with this lint:
+        block_in_if_condition_stmt))]
+
 #[macro_use(dbg)]
 extern crate cretonne;
 extern crate cton_reader;
@@ -44,7 +49,7 @@ type TestResult = Result<time::Duration, String>;
 /// Directories are scanned recursively for test cases ending in `.cton`. These test cases are
 /// executed on background threads.
 ///
-pub fn run(verbose: bool, files: Vec<String>) -> TestResult {
+pub fn run(verbose: bool, files: &[String]) -> TestResult {
     let mut runner = TestRunner::new(verbose);
 
     for path in files.iter().map(Path::new) {

lib/filetests/src/runner.rs

@@ -45,7 +45,7 @@ impl Display for QueueEntry {
                     f,
                     "{}.{:03} {}",
                     dur.as_secs(),
-                    dur.subsec_nanos() / 1000000,
+                    dur.subsec_nanos() / 1_000_000,
                     p
                 )
             }
@@ -135,7 +135,7 @@ impl TestRunner {
                     // This lets us skip spurious extensionless files without statting everything
                     // needlessly.
                     if !dir.is_file() {
-                        self.path_error(dir, err);
+                        self.path_error(&dir, &err);
                     }
                 }
                 Ok(entries) => {
@@ -149,7 +149,7 @@ impl TestRunner {
                                 // libstd/sys/unix/fs.rs seems to suggest that breaking now would
                                 // be a good idea, or the iterator could keep returning the same
                                 // error forever.
-                                self.path_error(dir, err);
+                                self.path_error(&dir, &err);
                                 break;
                             }
                             Ok(entry) => {
@@ -172,7 +172,7 @@ impl TestRunner {
     }
 
     /// Report an error related to a path.
-    fn path_error<E: Error>(&mut self, path: PathBuf, err: E) {
+    fn path_error<E: Error>(&mut self, path: &PathBuf, err: &E) {
         self.errors += 1;
         println!("{}: {}", path.to_string_lossy(), err);
     }

lib/filetests/src/runone.rs

@@ -132,7 +132,7 @@ fn run_one_test<'a>(
     if !context.verified && test.needs_verifier() {
         verify_function(&func, context.flags_or_isa()).map_err(
             |e| {
-                pretty_verifier_error(&func, isa, e)
+                pretty_verifier_error(&func, isa, &e)
             },
         )?;
         context.verified = true;

lib/filetests/src/subtest.rs

@@ -1,4 +1,4 @@
-//! SubTest trait.
+//! `SubTest` trait.
 
 use std::result;
 use std::borrow::Cow;