auto merge of #792 : alexcrichton/cargo/build-cmd, r=brson

This series of commits (based on #763) is an implementation of the recent [Cargo RFC](https://github.com/rust-lang/rfcs/blob/master/text/0403-cargo-build-command.md). This should implement all portions of the RFC, but there's a lot so an extra set of eyes would be nice!

I haven't added documentation for it all yet, but I would like to do so before landing (starting with #749). Otherwise I've been migrating all of the existing cargo dependencies away from the build command to a build script, and the progress can be seen with these repositories:

* https://github.com/alexcrichton/gcc-rs
* https://github.com/alexcrichton/pkg-config-rs
* https://github.com/alexcrichton/git2-rs/tree/build-cmd
* https://github.com/alexcrichton/openssl-sys
* https://github.com/alexcrichton/flate2-rs/tree/build-cmd
* https://github.com/alexcrichton/libz-sys
* https://github.com/alexcrichton/ssh2-rs/tree/build-cmd

I haven't quite gotten around to curl just yet, but it's next on my list!

Makefile.in

@@ -102,7 +102,7 @@ clean:
 
 # === Documentation
 
-DOCS := index faq config guide manifest native-build pkgid-spec
+DOCS := index faq config guide manifest build-script pkgid-spec
 DOC_DIR := target/doc
 DOC_OPTS := --markdown-no-toc \
 		--markdown-css stylesheets/normalize.css \

src/cargo/core/dependency.rs

@@ -10,7 +10,7 @@ pub struct Dependency {
     source_id: SourceId,
     req: VersionReq,
     specified_req: Option<String>,
-    transitive: bool,
+    kind: Kind,
     only_match_name: bool,
 
     optional: bool,
@@ -22,6 +22,13 @@ pub struct Dependency {
     only_for_platform: Option<String>,
 }
 
+#[deriving(PartialEq, Clone, Show)]
+pub enum Kind {
+    Normal,
+    Development,
+    Build,
+}
+
 impl Dependency {
     /// Attempt to create a `Dependency` from an entry in the manifest.
     ///
@@ -55,7 +62,7 @@ impl Dependency {
             name: name.to_string(),
             source_id: source_id.clone(),
             req: VersionReq::any(),
-            transitive: true,
+            kind: Normal,
             only_match_name: true,
             optional: false,
             features: Vec::new(),
@@ -83,8 +90,8 @@ impl Dependency {
         &self.source_id
     }
 
-    pub fn transitive(mut self, transitive: bool) -> Dependency {
-        self.transitive = transitive;
+    pub fn kind(mut self, kind: Kind) -> Dependency {
+        self.kind = kind;
         self
     }
 
@@ -132,7 +139,15 @@ impl Dependency {
     }
 
     /// Returns false if the dependency is only used to build the local package.
-    pub fn is_transitive(&self) -> bool { self.transitive }
+    pub fn is_transitive(&self) -> bool {
+        match self.kind {
+            Normal | Build => true,
+            Development => false,
+        }
+    }
+    pub fn is_build(&self) -> bool {
+        match self.kind { Build => true, _ => false }
+    }
     pub fn is_optional(&self) -> bool { self.optional }
     /// Returns true if the default features of the dependency are requested.
     pub fn uses_default_features(&self) -> bool { self.default_features }

src/cargo/core/manifest.rs

@@ -16,7 +16,8 @@ pub struct Manifest {
     targets: Vec<Target>,
     target_dir: Path,
     doc_dir: Path,
-    build: Vec<String>,
+    build: Vec<String>,         // TODO: deprecated, remove
+    links: Option<String>,
     warnings: Vec<String>,
     exclude: Vec<String>,
     metadata: ManifestMetadata,
@@ -59,7 +60,7 @@ pub struct SerializedManifest {
     targets: Vec<Target>,
     target_dir: String,
     doc_dir: String,
-    build: Option<Vec<String>>,
+    build: Option<Vec<String>>,     // TODO: deprecated, remove
 }
 
 impl<E, S: Encoder<E>> Encodable<S, E> for Manifest {
@@ -73,6 +74,7 @@ impl<E, S: Encoder<E>> Encodable<S, E> for Manifest {
             targets: self.targets.clone(),
             target_dir: self.target_dir.display().to_string(),
             doc_dir: self.doc_dir.display().to_string(),
+            // TODO: deprecated, remove
             build: if self.build.len() == 0 { None } else { Some(self.build.clone()) },
         }.encode(s)
     }
@@ -131,8 +133,9 @@ pub struct Profile {
     doctest: bool,
     doc: bool,
     dest: Option<String>,
-    plugin: bool,
+    for_host: bool,
     harness: bool, // whether to use the test harness (--test)
+    custom_build: bool,
 }
 
 impl Profile {
@@ -146,8 +149,9 @@ impl Profile {
             test: false,
             doc: false,
             dest: None,
-            plugin: false,
+            for_host: false,
             doctest: false,
+            custom_build: false,
             harness: true,
         }
     }
@@ -219,8 +223,13 @@ impl Profile {
         self.doctest
     }
 
-    pub fn is_plugin(&self) -> bool {
-        self.plugin
+    pub fn is_custom_build(&self) -> bool {
+        self.custom_build
+    }
+
+    /// Returns true if the target must be built for the host instead of the target.
+    pub fn is_for_host(&self) -> bool {
+        self.for_host
     }
 
     pub fn get_opt_level(&self) -> uint {
@@ -282,15 +291,22 @@ impl Profile {
         self
     }
 
-    pub fn plugin(mut self, plugin: bool) -> Profile {
-        self.plugin = plugin;
+    /// Sets whether the `Target` must be compiled for the host instead of the target platform.
+    pub fn for_host(mut self, for_host: bool) -> Profile {
+        self.for_host = for_host;
         self
     }
 
     pub fn harness(mut self, harness: bool) -> Profile {
         self.harness = harness;
         self
     }
+
+    /// Sets whether the `Target` is a custom build script.
+    pub fn custom_build(mut self, custom_build: bool) -> Profile {
+        self.custom_build = custom_build;
+        self
+    }
 }
 
 impl<H: hash::Writer> hash::Hash<H> for Profile {
@@ -302,7 +318,7 @@ impl<H: hash::Writer> hash::Hash<H> for Profile {
             codegen_units,
             debug,
             rpath,
-            plugin,
+            for_host,
             ref dest,
             harness,
 
@@ -313,8 +329,10 @@ impl<H: hash::Writer> hash::Hash<H> for Profile {
             env: _,
             test: _,
             doctest: _,
+
+            custom_build: _,
         } = *self;
-        (opt_level, codegen_units, debug, rpath, plugin, dest, harness).hash(into)
+        (opt_level, codegen_units, debug, rpath, for_host, dest, harness).hash(into)
     }
 }
 
@@ -366,16 +384,17 @@ impl Show for Target {
 impl Manifest {
     pub fn new(summary: Summary, targets: Vec<Target>,
                target_dir: Path, doc_dir: Path,
-               build: Vec<String>, exclude: Vec<String>,
+               build: Vec<String>, exclude: Vec<String>, links: Option<String>,
                metadata: ManifestMetadata) -> Manifest {
         Manifest {
             summary: summary,
             targets: targets,
             target_dir: target_dir,
             doc_dir: doc_dir,
-            build: build,
+            build: build,     // TODO: deprecated, remove
             warnings: Vec::new(),
             exclude: exclude,
+            links: links,
             metadata: metadata,
         }
     }
@@ -416,6 +435,10 @@ impl Manifest {
         self.build.as_slice()
     }
 
+    pub fn get_links(&self) -> Option<&str> {
+        self.links.as_ref().map(|s| s.as_slice())
+    }
+
     pub fn add_warning(&mut self, s: String) {
         self.warnings.push(s)
     }
@@ -466,6 +489,18 @@ impl Target {
         }
     }
 
+    /// Builds a `Target` corresponding to the `build = "build.rs"` entry.
+    pub fn custom_build_target(name: &str, src_path: &Path, profile: &Profile,
+                               metadata: Option<Metadata>) -> Target {
+        Target {
+            kind: BinTarget,
+            name: name.to_string(),
+            src_path: src_path.clone(),
+            profile: profile.clone(),
+            metadata: metadata,
+        }
+    }
+
     pub fn example_target(name: &str, src_path: &Path, profile: &Profile) -> Target {
         Target {
             kind: ExampleTarget,

src/cargo/ops/cargo_clean.rs

@@ -1,3 +1,4 @@
+use std::collections::HashMap;
 use std::io::fs::{mod, PathExtensions};
 
 use core::{MultiShell, PackageSet};
@@ -49,7 +50,7 @@ pub fn clean(manifest_path: &Path, opts: &mut CleanOptions) -> CargoResult<()> {
     let pkgs = PackageSet::new([]);
     let cx = try!(Context::new("compile", &resolve, &srcs, &pkgs, &mut cfg,
                                Layout::at(root.get_absolute_target_dir()),
-                               None, &pkg));
+                               None, &pkg, HashMap::new()));
 
     // And finally, clean everything out!
     for target in pkg.get_targets().iter() {

src/cargo/ops/cargo_compile.rs

@@ -28,7 +28,7 @@ use std::collections::HashMap;
 use core::registry::PackageRegistry;
 use core::{MultiShell, Source, SourceId, PackageSet, Package, Target, PackageId};
 use core::resolver;
-use ops;
+use ops::{mod, BuildOutput};
 use sources::{PathSource};
 use util::config::{Config, ConfigValue};
 use util::{CargoResult, Wrap, config, internal, human, ChainError, profile};
@@ -129,7 +129,7 @@ pub fn compile_pkg(package: &Package, options: &mut CompileOptions)
     };
 
     let targets = to_build.get_targets().iter().filter(|target| {
-        match env {
+        target.get_profile().is_custom_build() || match env {
             // doc-all == document everything, so look for doc targets
             "doc" | "doc-all" => target.get_profile().get_env() == "doc",
             env => target.get_profile().get_env() == env,
@@ -138,12 +138,12 @@ pub fn compile_pkg(package: &Package, options: &mut CompileOptions)
 
     let ret = {
         let _p = profile::start("compiling");
-        try!(scrape_target_config(&config, &user_configs));
+        let lib_overrides = try!(scrape_target_config(&config, &user_configs));
 
         try!(ops::compile_targets(env.as_slice(), targets.as_slice(), to_build,
                                   &PackageSet::new(packages.as_slice()),
                                   &resolve_with_overrides, &sources,
-                                  &config))
+                                  &config, lib_overrides))
     };
 
     return Ok(ret);
@@ -175,41 +175,68 @@ fn source_ids_from_config(configs: &HashMap<String, config::ConfigValue>,
 
 fn scrape_target_config(config: &Config,
                         configs: &HashMap<String, config::ConfigValue>)
-                        -> CargoResult<()> {
+                        -> CargoResult<HashMap<String, BuildOutput>> {
     let target = match configs.find_equiv("target") {
-        None => return Ok(()),
+        None => return Ok(HashMap::new()),
         Some(target) => try!(target.table().chain_error(|| {
             internal("invalid configuration for the key `target`")
         })),
     };
-    let target = match config.target() {
-        None => target,
-        Some(triple) => match target.find_equiv(triple) {
-            None => return Ok(()),
-            Some(target) => try!(target.table().chain_error(|| {
-                internal(format!("invalid configuration for the key \
-                                  `target.{}`", triple))
-            })),
-        },
+    let triple = config.target().unwrap_or(config.rustc_host()).to_string();
+    let target = match target.find(&triple) {
+        None => return Ok(HashMap::new()),
+        Some(target) => try!(target.table().chain_error(|| {
+            internal(format!("invalid configuration for the key \
+                              `target.{}`", triple))
+        })),
     };
 
-    match target.find_equiv("ar") {
-        None => {}
-        Some(ar) => {
-            config.set_ar(try!(ar.string().chain_error(|| {
-                internal("invalid configuration for key `ar`")
-            })).ref0().to_string());
-        }
-    }
-
-    match target.find_equiv("linker") {
-        None => {}
-        Some(linker) => {
-            config.set_linker(try!(linker.string().chain_error(|| {
-                internal("invalid configuration for key `ar`")
-            })).ref0().to_string());
+    let mut ret = HashMap::new();
+    for (k, v) in target.iter() {
+        match k.as_slice() {
+            "ar" | "linker" => {
+                let v = try!(v.string().chain_error(|| {
+                    internal(format!("invalid configuration for key `{}`", k))
+                })).ref0().to_string();
+                if k.as_slice() == "linker" {
+                    config.set_linker(v);
+                } else {
+                    config.set_ar(v);
+                }
+            }
+            lib_name => {
+                let table = try!(v.table().chain_error(|| {
+                    internal(format!("invalid configuration for the key \
+                                      `target.{}.{}`", triple, lib_name))
+                }));
+                let mut output = BuildOutput {
+                    library_paths: Vec::new(),
+                    library_links: Vec::new(),
+                    metadata: Vec::new(),
+                };
+                for (k, v) in table.iter() {
+                    let v = try!(v.string().chain_error(|| {
+                        internal(format!("invalid configuration for the key \
+                                          `target.{}.{}.{}`", triple, lib_name,
+                                          k))
+                    })).val0();
+                    if k.as_slice() == "rustc-flags" {
+                        let whence = format!("in `target.{}.{}.rustc-flags`",
+                                             triple, lib_name);
+                        let whence = whence.as_slice();
+                        let (paths, links) = try!(
+                            BuildOutput::parse_rustc_flags(v.as_slice(), whence)
+                        );
+                        output.library_paths.extend(paths.into_iter());
+                        output.library_links.extend(links.into_iter());
+                    } else {
+                        output.metadata.push((k.to_string(), v.to_string()));
+                    }
+                }
+                ret.insert(lib_name.to_string(), output);
+            }
         }
     }
 
-    Ok(())
+    Ok(ret)
 }

src/cargo/ops/cargo_run.rs

@@ -22,7 +22,8 @@ pub fn run(manifest_path: &Path,
             LibTarget(_) => false,
         };
         let matches_name = name.as_ref().map_or(true, |n| n.as_slice() == a.get_name());
-        matches_kind && matches_name && a.get_profile().get_env() == env
+        matches_kind && matches_name && a.get_profile().get_env() == env &&
+            !a.get_profile().is_custom_build()
     });
     let bin = try!(bins.next().require(|| {
         human("a bin target must be available for `cargo run`")

src/cargo/ops/cargo_rustc/compilation.rs

@@ -23,6 +23,7 @@ pub struct Compilation {
     ///
     /// This is currently used to drive some entries which are added to the
     /// LD_LIBRARY_PATH as appropriate.
+    // TODO: deprecated, remove
     pub native_dirs: HashMap<PackageId, Path>,
 
     /// Root output directory (for the local package's artifacts)
@@ -43,7 +44,7 @@ impl Compilation {
     pub fn new(pkg: &Package) -> Compilation {
         Compilation {
             libraries: HashMap::new(),
-            native_dirs: HashMap::new(),
+            native_dirs: HashMap::new(),  // TODO: deprecated, remove
             root_output: Path::new("/"),
             deps_output: Path::new("/"),
             tests: Vec::new(),