switch to cargo_metadata for dep info

Switched from using Cargo to resolve the dependencies to using the
cargo_metadata crate, which calls Cargo and parses the machine parseable
data back.

4 files changed, 44 insertions, 55 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 475d694..882e910 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -158,11 +158,24 @@ name = "cargo-ebuild"
 version = "0.2.1-alpha.0"
 dependencies = [
  "cargo 0.37.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cargo_metadata 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "structopt 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
+name = "cargo_metadata"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.41 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "cc"
 version = "1.0.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1202,6 +1215,7 @@ dependencies = [
 "checksum bytesize 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "716960a18f978640f25101b5cbf1c6f6b0d3192fab36a2d98ca96f0ecbe41010"
 "checksum c2-chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7d64d04786e0f528460fc884753cf8dddcc466be308f6026f8e355c41a0e4101"
 "checksum cargo 0.37.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e6924b75f0de3b87ffd13f291224a2eb0f92e961b287d900863fc586f8ecd833"
+"checksum cargo_metadata 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "46e3374c604fb39d1a2f35ed5e4a4e30e60d01fab49446e08f1b3e9a90aef202"
 "checksum cc 1.0.45 (registry+https://github.com/rust-lang/crates.io-index)" = "4fc9a35e1f4290eb9e5fc54ba6cf40671ed2a2514c3eeb2b2a908dda2ea5a1be"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
diff --git a/Cargo.toml b/Cargo.toml
index ab7e8d1..828d38d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,5 +30,7 @@ maintenance = { status = "passively-maintained" }
 
 [dependencies]
 cargo = "^0.37"
+cargo_metadata = "^0.9"
+failure = "^0.1"
 structopt = "^0.3"
 time = "^0.1"
diff --git a/src/lib.rs b/src/lib.rs
index 2903814..3258dbc 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,59 +13,41 @@ extern crate time;
 
 mod metadata;
 
-use cargo::core::registry::PackageRegistry;
-use cargo::core::resolver::Method;
-use cargo::core::{Package, PackageSet, Resolve, Workspace};
-use cargo::ops;
+use cargo::core::Workspace;
 use cargo::util::{important_paths, CargoResult};
 use cargo::{CliResult, Config};
+use failure::format_err;
 use std::fs::OpenOptions;
 use std::io::Write;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use metadata::EbuildConfig;
 
 /// Finds the root Cargo.toml of the workspace
-fn workspace(config: &Config) -> CargoResult<Workspace> {
-    let root = important_paths::find_root_manifest_for_wd(config.cwd())?;
+fn workspace(config: &Config, manifest: impl AsRef<Path>) -> CargoResult<Workspace> {
+    let root = important_paths::find_root_manifest_for_wd(manifest.as_ref())?;
     Workspace::new(&root, config)
 }
 
-/// Generates a package registry by using the Cargo.lock or creating one as necessary
-fn registry<'a>(config: &'a Config, package: &Package) -> CargoResult<PackageRegistry<'a>> {
-    let mut registry = PackageRegistry::new(config)?;
-    registry.add_sources(vec![package.package_id().source_id()])?;
-    Ok(registry)
-}
+pub fn run(verbose: u32, quiet: bool, manifest_path: Option<PathBuf>) -> CliResult {
+    let mut cmd = cargo_metadata::MetadataCommand::new();
 
-/// Resolve the packages necessary for the workspace
-fn resolve<'a>(
-    registry: &mut PackageRegistry<'a>,
-    workspace: &Workspace<'a>,
-) -> CargoResult<(PackageSet<'a>, Resolve)> {
-    // resolve our dependencies
-    let (packages, resolve) = ops::resolve_ws(workspace)?;
-
-    // resolve with all features set so we ensure we get all of the depends downloaded
-    let resolve = ops::resolve_with_previous(
-        registry,
-        workspace,
-        /* resolve it all */
-        Method::Everything,
-        /* previous */
-        Some(&resolve),
-        /* don't avoid any */
-        None,
-        /* specs */
-        &[],
-        /* warn */
-        true,
-    )?;
+    if let Some(path) = manifest_path {
+        cmd.manifest_path(path);
+    }
 
-    Ok((packages, resolve))
-}
+    let metadata = cmd
+        .exec()
+        .map_err(|e| format_err!("cargo metadata failed: {}", e))?;
+
+    let mut crates = Vec::with_capacity(metadata.packages.len());
+    for pkg in metadata.packages {
+        crates.push(format!("{}-{}\n", pkg.name, pkg.version));
+    }
+
+    // sort the crates
+    crates.sort();
 
-pub fn run(verbose: u32, quiet: bool) -> CliResult {
     // create a default Cargo config
     let mut config = Config::default()?;
 
@@ -87,23 +69,9 @@ pub fn run(verbose: u32, quiet: bool) -> CliResult {
     )?;
 
     // Load the workspace and current package
-    let workspace = workspace(&config)?;
+    let workspace = workspace(&config, &metadata.workspace_root)?;
     let package = workspace.current()?;
 
-    // Resolve all dependencies (generate or use Cargo.lock as necessary)
-    let mut registry = registry(&config, &package)?;
-    let resolve = resolve(&mut registry, &workspace)?;
-
-    // build the crates the package needs
-    let mut crates = resolve
-        .1
-        .iter()
-        .map(|pkg| format!("{}-{}\n", pkg.name(), pkg.version()))
-        .collect::<Vec<String>>();
-
-    // sort the crates
-    crates.sort();
-
     let ebuild_data = EbuildConfig::from_package(package, crates);
 
     // build up the ebuild path
diff --git a/src/main.rs b/src/main.rs
index 1f27e47..7999b8e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -14,6 +14,7 @@ extern crate structopt;
 
 use cargo::util::CliError;
 use cargo_ebuild::run;
+use std::path::PathBuf;
 use std::process;
 use structopt::clap::AppSettings;
 use structopt::StructOpt;
@@ -26,6 +27,10 @@ struct Args {
     /// Verbose mode (-v, -vv, -vvv, etc.)
     #[structopt(short = "v", long = "verbose", parse(from_occurrences))]
     verbose: usize,
+
+    #[structopt(name = "PATH", long = "manifest-path", parse(from_os_str))]
+    /// Path to Cargo.toml.
+    manifest_path: Option<PathBuf>,
 }
 
 #[structopt(
@@ -46,7 +51,7 @@ fn main() {
     let Opt::Ebuild(opt) = Opt::from_args();
 
     // run the actual code
-    if let Err(e) = run(opt.verbose as u32, opt.quiet) {
+    if let Err(e) = run(opt.verbose as u32, opt.quiet, opt.manifest_path) {
         // break apart the error
         let CliError {
             error,