Add infrastructure for an Error type, config options, and CLI args

.travis.yml

@@ -1,21 +1,42 @@
 language: rust
 
+dist: trusty
+
+os:
+  - linux
+  - osx
+
+addons:
+  apt:
+    sources:
+      # Provides newer gcc.
+      - ubuntu-toolchain-r-test
+      # Provides libclang 3.9.
+      - llvm-toolchain-trusty-3.9
+    packages:
+      - autoconf2.13
+      # bindgen requires libclang >= 3.9.
+      - clang-3.9
+      # SpiderMonkey needs gcc >= 4.9 and 5 is ICEing.
+      - gcc-6
+      - g++-6
+
 rust:
-  - stable
-  - beta
   - nightly
 
 cache: cargo
 
 env:
   matrix:
-    - PROFILE="--release"
-    - PROFILE=""
+    - PROFILE="--release" FEATURES=""
+    - PROFILE=""          FEATURES=""
+    - PROFILE="--release" FEATURES="--features debugmozjs"
+    - PROFILE=""          FEATURES="--features debugmozjs"
 
+before_install:
+- source ./ci/before_install.sh
 
 script:
-  - cargo build $PROFILE --verbose
-  - cargo test $PROFILE --verbose
-  - if [[ "$PROFILE" == "--release" ]]; then
-        cargo bench;
-    fi
+  - ccache -z
+  - PROFILE="$PROFILE" FEATURES="$FEATURES" travis_wait ./ci/script.sh
+  - ccache --show-stats

Cargo.toml

@@ -1,17 +1,31 @@
 [package]
-authors = ["Nick Fitzgerald <[email protected]>"]
+authors = ["The Starling Project Developers"]
+description = "The project that will henceforth be known as `starling`."
 name = "starling"
 version = "0.1.0"
-
 [[bin]]
+doc = false
 name = "starling"
 path = "src/bin/starling.rs"
-doc = false
+required-features = ["clap"]
 
 [dependencies]
+error-chain = "0.10.0"
 futures = "0.1.13"
 tokio-core = "0.1.6"
 
+[dependencies.clap]
+optional = true
+version = "2.26.0"
+
+[dependencies.backtrace]
+features = ["cpp_demangle"]
+version = "0.3.2"
+
 [dependencies.js]
-git = "https://github.com/fitzgen/mozjs"
 branch = "smup"
+git = "https://github.com/fitzgen/mozjs"
+
+[features]
+default = ["clap"]
+debugmozjs = ['js/debugmozjs']

ci/before_install.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+# We always want backtraces for everything.
+export RUST_BACKTRACE=1
+
+if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
+    brew install [email protected] ccache [email protected] yasm
+    export LIBCLANG_PATH=$(find /usr/local/Cellar/llvm -type f -name libclang.dylib | head -n 1)
+    export LIBCLANG_PATH=$(dirname $LIBCLANG_PATH)
+elif [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
+    export CC=clang-3.9
+    export CXX=clang++-3.9
+    export LIBCLANG_PATH=/usr/lib/llvm-3.9/lib
+else
+    echo "Error: unknown \$TRAVIS_OS_NAME: $TRAVIS_OS_NAME"
+    exit 1
+fi
+
+ccache -c
+export CCACHE=$(which ccache)

ci/script.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+set -eux
+
+cargo build -v $PROFILE $FEATURES
+cargo test -v $PROFILE $FEATURES
+
+if [[ "$PROFILE" == "--release" && "$FEATURES" == "" ]]; then
+    cargo bench -v
+fi

rustfmt.toml

@@ -0,0 +1,5 @@
+reorder_imports = true
+reorder_imported_names = true
+write_mode = "Overwrite"
+closure_block_indent_threshold = 0
+use_try_shorthand = true

src/bin/starling.rs

@@ -1,10 +1,37 @@
+extern crate clap;
+extern crate error_chain;
 extern crate starling;
 
+use clap::{App, Arg};
+use error_chain::ChainedError;
 use std::process;
 
+/// Parse the given CLI arguments into a `starling::Options` configuration
+/// object.
+///
+/// If argument parsing fails, then a usage string is printed, and the process
+/// is exited with 1.
+fn parse_cli_args() -> starling::Options {
+    let matches = App::new(env!("CARGO_PKG_NAME"))
+        .version(env!("CARGO_PKG_VERSION"))
+        .author(env!("CARGO_PKG_AUTHORS"))
+        .about(env!("CARGO_PKG_DESCRIPTION"))
+        .arg(
+            Arg::with_name("file")
+                .required(true)
+                .help("The JavaScript file to evaluate as the main task."),
+        )
+        .get_matches();
+
+    let opts = starling::Options::new(matches.value_of("file").unwrap());
+
+    opts
+}
+
 fn main() {
-    if let Err(e) = starling::run() {
-        println!("Error: {}", e);
+    let opts = parse_cli_args();
+    if let Err(e) = opts.run() {
+        println!("{}", e.display());
         process::exit(1);
     }
 }

src/lib.rs

@@ -1,21 +1,74 @@
 //! The project that will henceforth be known as `starling`.
-
+//!
+// `error_chain!` can recurse deeply
+#![recursion_limit = "1024"]
 #![deny(missing_docs)]
 #![deny(missing_debug_implementations)]
+#![deny(unsafe_code)]
+// Annoying warning emitted from the `error_chain!` macro.
+#![allow(unused_doc_comment)]
 
+#[macro_use]
+extern crate error_chain;
 extern crate futures;
 extern crate tokio_core;
 
 use futures::future;
-use std::io;
+use std::path;
 use tokio_core::reactor::Core;
 
-/// Run the main `starling` loop.
-pub fn run() -> Result<(), io::Error> {
+error_chain! {
+    foreign_links {
+        Io(::std::io::Error)
+        /// An IO error.
+            ;
+    }
+}
+
+/// Configuration options for building a `starling` event loop.
+///
+/// ```
+/// extern crate starling;
+///
+/// # fn foo() -> starling::Result<()> {
+/// // Construct a new `Options` builder, providing the file containing
+/// // the main JavaScript task.
+/// starling::Options::new("path/to/main.js")
+///     // Finish configuring the `Options` builder and run the event
+///     // loop!
+///     .run()?;
+/// # Ok(())
+/// # }
+/// ```
+#[derive(Clone, Debug)]
+pub struct Options {
+    main: path::PathBuf,
+}
+
+impl Options {
+    /// Construct a new `Options` object for configuring the `starling` event
+    /// loop.
+    ///
+    /// The given `main` JavaScript file will be evaluated as the main task.
+    pub fn new<P>(main: P) -> Options
+    where
+        P: Into<path::PathBuf>,
+    {
+        Options { main: main.into() }
+    }
+
+    /// Finish this `Options` builder and run the `starling` event loop with its
+    /// specified configuration.
+    pub fn run(self) -> Result<()> {
+        run_with_options(self)
+    }
+}
+
+/// Run the main `starling` event loop with the specified options.
+fn run_with_options(_opts: Options) -> Result<()> {
     let mut core = Core::new()?;
     core.run(future::ok(()))
 }
 
 #[test]
-fn it_works() {
-}
+fn it_works() {}