Migrate from rustc-serialize to Serde

This commit migrates Cargo as much as possible from rustc-serialize to
Serde. This not only provides an excellent testing ground for the toml
0.3 release but it also is a big boost to the speed of parsing the JSON
bits of the registry.

This doesn't completely excise the dependency just yet as docopt still
requires it along with handlebars. I'm sure though that in time those
crates will migrate to serde!

Cargo.toml

@@ -35,11 +35,15 @@ log = "0.3"
 num_cpus = "1.0"
 rustc-serialize = "0.3"
 semver = "0.6.0"
+serde = "0.9"
+serde_derive = "0.9"
+serde_json = "0.9"
+serde_ignored = "0.0.2"
 shell-escape = "0.1"
 tar = { version = "0.4", default-features = false }
 tempdir = "0.3"
 term = "0.4.4"
-toml = "0.2"
+toml = "0.3"
 url = "1.1"
 
 [target.'cfg(unix)'.dependencies]

src/bin/cargo.rs

@@ -6,6 +6,9 @@ extern crate rustc_serialize;
 extern crate toml;
 #[macro_use]
 extern crate log;
+#[macro_use]
+extern crate serde_derive;
+extern crate serde_json;
 
 use std::collections::BTreeSet;
 use std::collections::HashMap;

src/bin/locate_project.rs

@@ -18,7 +18,7 @@ Options:
     -h, --help              Print this message
 ";
 
-#[derive(RustcEncodable)]
+#[derive(Serialize)]
 pub struct ProjectLocation {
     root: String
 }

src/bin/verify_project.rs

@@ -6,7 +6,7 @@ use std::process;
 use cargo;
 use cargo::util::important_paths::{find_root_manifest_for_wd};
 use cargo::util::{CliResult, Config};
-use rustc_serialize::json;
+use serde_json;
 use toml;
 
 #[derive(RustcDecodable)]
@@ -55,10 +55,9 @@ pub fn execute(args: Flags, config: &Config) -> CliResult {
         Ok(_) => {},
         Err(e) => fail("invalid", &format!("error reading file: {}", e))
     };
-    match toml::Parser::new(&contents).parse() {
-        None => fail("invalid", "invalid-format"),
-        Some(..) => {}
-    };
+    if contents.parse::<toml::Value>().is_err() {
+        fail("invalid", "invalid-format");
+    }
 
     let mut h = HashMap::new();
     h.insert("success".to_string(), "true".to_string());
@@ -69,6 +68,6 @@ pub fn execute(args: Flags, config: &Config) -> CliResult {
 fn fail(reason: &str, value: &str) -> ! {
     let mut h = HashMap::new();
     h.insert(reason.to_string(), value.to_string());
-    println!("{}", json::encode(&h).unwrap());
+    println!("{}", serde_json::to_string(&h).unwrap());
     process::exit(1)
 }

src/cargo/core/dependency.rs

@@ -4,7 +4,7 @@ use std::str::FromStr;
 
 use semver::VersionReq;
 use semver::ReqParseError;
-use rustc_serialize::{Encoder, Encodable};
+use serde::ser;
 
 use core::{SourceId, Summary, PackageId};
 use util::{CargoError, CargoResult, Cfg, CfgExpr, ChainError, human, Config};
@@ -41,7 +41,7 @@ pub enum Platform {
     Cfg(CfgExpr),
 }
 
-#[derive(RustcEncodable)]
+#[derive(Serialize)]
 struct SerializedDependency<'a> {
     name: &'a str,
     source: &'a SourceId,
@@ -54,8 +54,10 @@ struct SerializedDependency<'a> {
     target: Option<&'a Platform>,
 }
 
-impl Encodable for Dependency {
-    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
+impl ser::Serialize for Dependency {
+    fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
+        where S: ser::Serializer,
+    {
         SerializedDependency {
             name: self.name(),
             source: &self.source_id(),
@@ -65,7 +67,7 @@ impl Encodable for Dependency {
             uses_default_features: self.uses_default_features(),
             features: self.features(),
             target: self.platform(),
-        }.encode(s)
+        }.serialize(s)
     }
 }
 
@@ -76,13 +78,15 @@ pub enum Kind {
     Build,
 }
 
-impl Encodable for Kind {
-    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
+impl ser::Serialize for Kind {
+    fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
+        where S: ser::Serializer,
+    {
         match *self {
             Kind::Normal => None,
             Kind::Development => Some("dev"),
             Kind::Build => Some("build"),
-        }.encode(s)
+        }.serialize(s)
     }
 }
 
@@ -136,7 +140,7 @@ This will soon become a hard error, so it's either recommended to
 update to a fixed version or contact the upstream maintainer about
 this warning.
 ",
-	req, inside.name(), inside.version(), requirement);
+    req, inside.name(), inside.version(), requirement);
                         config.shell().warn(&msg)?;
 
                         Ok(requirement)
@@ -348,9 +352,11 @@ impl Platform {
     }
 }
 
-impl Encodable for Platform {
-    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
-        self.to_string().encode(s)
+impl ser::Serialize for Platform {
+    fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
+        where S: ser::Serializer,
+    {
+        self.to_string().serialize(s)
     }
 }