path: root/src/librustpkg/rustpkg.rs

// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// rustpkg - a package manager and build system for Rust

#[link(name = "rustpkg",
       vers = "0.8-pre",
       uuid = "25de5e6e-279e-4a20-845c-4cabae92daaf",
       url = "https://github.com/mozilla/rust/tree/master/src/librustpkg")];

#[license = "MIT/ASL2"];
#[crate_type = "lib"];

extern mod extra;
extern mod rustc;
extern mod syntax;

use std::{io, os, result, run, str};
pub use std::path::Path;

use extra::workcache;
use extra::arc::RWArc;
use rustc::driver::{driver, session};
use rustc::metadata::filesearch;
use rustc::metadata::filesearch::rust_path;
use extra::{getopts};
use syntax::{ast, diagnostic};
use util::*;
use messages::{error, warn, note};
use path_util::build_pkg_id_in_workspace;
use path_util::{U_RWX, in_rust_path};
use path_util::{built_executable_in_workspace, built_library_in_workspace, default_workspace};
use path_util::{target_executable_in_workspace, target_library_in_workspace};
use source_control::is_git_dir;
use workspace::{each_pkg_parent_workspace, pkg_parent_workspaces, cwd_to_workspace};
use context::{Context, BuildContext,
                       RustcFlags, Trans, Link, Nothing, Pretty, Analysis, Assemble,
                       LLVMAssemble, LLVMCompileBitcode};
use package_id::PkgId;
use package_source::PkgSrc;
use workcache_support::{discover_outputs, digest_only_date};

pub mod api;
mod conditions;
mod context;
mod crate;
mod installed_packages;
mod messages;
mod package_id;
mod package_source;
mod path_util;
mod search;
mod source_control;
mod target;
#[cfg(test)]
mod tests;
mod util;
mod version;
pub mod workcache_support;
mod workspace;

pub mod usage;

/// A PkgScript represents user-supplied custom logic for
/// special build hooks. This only exists for packages with
/// an explicit package script.
struct PkgScript<'self> {
    /// Uniquely identifies this package
    id: &'self PkgId,
    /// File path for the package script
    input: Path,
    /// The session to use *only* for compiling the custom
    /// build script
    sess: session::Session,
    /// The config for compiling the custom build script
    cfg: ast::CrateConfig,
    /// The crate for the custom build script
    crate: @ast::Crate,
    /// Directory in which to store build output
    build_dir: Path
}

impl<'self> PkgScript<'self> {
    /// Given the path name for a package script
    /// and a package ID, parse the package script into
    /// a PkgScript that we can then execute
    fn parse<'a>(sysroot: @Path,
                 script: Path,
                 workspace: &Path,
                 id: &'a PkgId) -> PkgScript<'a> {
        // Get the executable name that was invoked
        let binary = os::args()[0].to_managed();
        // Build the rustc session data structures to pass
        // to the compiler
        debug!("pkgscript parse: %s", sysroot.to_str());
        let options = @session::options {
            binary: binary,
            maybe_sysroot: Some(sysroot),
            crate_type: session::bin_crate,
            .. (*session::basic_options()).clone()
        };
        let input = driver::file_input(script.clone());
        let sess = driver::build_session(options, diagnostic::emit);
        let cfg = driver::build_configuration(sess);
        let crate = driver::phase_1_parse_input(sess, cfg.clone(), &input);
        let crate = driver::phase_2_configure_and_expand(sess, cfg.clone(), crate);
        let work_dir = build_pkg_id_in_workspace(id, workspace);

        debug!("Returning package script with id %s", id.to_str());

        PkgScript {
            id: id,
            input: script,
            sess: sess,
            cfg: cfg,
            crate: crate,
            build_dir: work_dir
        }
    }

    /// Run the contents of this package script, where <what>
    /// is the command to pass to it (e.g., "build", "clean", "install")
    /// Returns a pair of an exit code and list of configs (obtained by
    /// calling the package script's configs() function if it exists
    fn run_custom(&self, exec: &mut workcache::Exec, sysroot: &Path) -> (~[~str], ExitCode) {
        let sess = self.sess;

        debug!("Working directory = %s", self.build_dir.to_str());
        // Collect together any user-defined commands in the package script
        let crate = util::ready_crate(sess, self.crate);
        debug!("Building output filenames with script name %s",
               driver::source_name(&driver::file_input(self.input.clone())));
        let exe = self.build_dir.push(~"pkg" + util::exe_suffix());
        util::compile_crate_from_input(&self.input,
                                       exec,
                                       Nothing,
                                       &self.build_dir,
                                       sess,
                                       crate);
        debug!("Running program: %s %s %s", exe.to_str(),
               sysroot.to_str(), "install");
        // Discover the output
        exec.discover_output("binary", exe.to_str(), digest_only_date(&exe));
        // FIXME #7401 should support commands besides `install`
        let status = run::process_status(exe.to_str(), [sysroot.to_str(), ~"install"]);
        if status != 0 {
            return (~[], status);
        }
        else {
            debug!("Running program (configs): %s %s %s",
                   exe.to_str(), sysroot.to_str(), "configs");
            let output = run::process_output(exe.to_str(), [sysroot.to_str(), ~"configs"]);
            // Run the configs() function to get the configs
            let cfgs = str::from_utf8_slice(output.output).word_iter()
                .map(|w| w.to_owned()).collect();
            (cfgs, output.status)
        }
    }

    fn hash(&self) -> ~str {
        self.id.hash()
    }
}

pub trait CtxMethods {
    fn run(&self, cmd: &str, args: ~[~str]);
    fn do_cmd(&self, _cmd: &str, _pkgname: &str);
    fn build_from_src(&self, pkg_src: PkgSrc);
    /// Returns the destination workspace
    fn build(&self, exec: &mut workcache::Exec, pkg_src: PkgSrc) -> Path;
    fn clean(&self, workspace: &Path, id: &PkgId);
    fn info(&self);
    /// Returns a pair. First component is a list of installed paths,
    /// second is a list of declared and discovered inputs
    fn install(&self, src: PkgSrc) -> (~[Path], ~[(~str, ~str)]);
    /// Returns a list of installed files
    fn install_no_build(&self,
                        source_workspace: &Path,
                        target_workspace: &Path,
                        id: &PkgId) -> ~[Path];
    fn prefer(&self, _id: &str, _vers: Option<~str>);
    fn test(&self);
    fn uninstall(&self, _id: &str, _vers: Option<~str>);
    fn unprefer(&self, _id: &str, _vers: Option<~str>);
    fn init(&self);
}

impl CtxMethods for BuildContext {
    fn build_from_src(&self, pkg_src: PkgSrc) {
        let tag = pkg_src.id.to_str();
        debug!("package source = %s", pkg_src.to_str());
        do self.workcache_context.with_prep(tag) |prep| {
            let subsrc = pkg_src.clone();
            let subself = self.clone();
            declare_package_script_dependency(prep, &subsrc);
            pkg_src.declare_inputs(prep);
            do prep.exec |exec| {
                subself.build(exec, subsrc.clone());
            }
        }
    }

    fn run(&self, cmd: &str, args: ~[~str]) {
        match cmd {
            "build" => {
                if args.len() < 1 {
                    match cwd_to_workspace() {
                        None if self.context.use_rust_path_hack => {
                            let cwd = os::getcwd();
                            let pkgid = PkgId::new(cwd.components[cwd.components.len() - 1]);
                            self.build_from_src(PkgSrc::new(cwd, true, pkgid));
                        }
                        None => { usage::build(); return; }
                        Some((ws, pkgid)) => {
                            self.build_from_src(PkgSrc::new(ws, false, pkgid));
                        }
                    }
                }
                else {
                    // The package id is presumed to be the first command-line
                    // argument
                    let pkgid = PkgId::new(args[0].clone());
                    do each_pkg_parent_workspace(&self.context, &pkgid) |workspace| {
                        debug!("found pkg %s in workspace %s, trying to build",
                               pkgid.to_str(), workspace.to_str());
                        let pkg_src = PkgSrc::new(workspace.clone(), false, pkgid.clone());
                        self.build_from_src(pkg_src);
                        true
                    };
                }
            }
            "clean" => {
                if args.len() < 1 {
                    match cwd_to_workspace() {
                        None => { usage::clean(); return }
                        // tjc: Maybe clean should clean all the packages in the
                        // current workspace, though?
                        Some((ws, pkgid)) => self.clean(&ws, &pkgid)
                    }

                }
                else {
                    // The package id is presumed to be the first command-line
                    // argument
                    let pkgid = PkgId::new(args[0].clone());
                    let cwd = os::getcwd();
                    self.clean(&cwd, &pkgid); // tjc: should use workspace, not cwd
                }
            }
            "do" => {
                if args.len() < 2 {
                    return usage::do_cmd();
                }

                self.do_cmd(args[0].clone(), args[1].clone());
            }
            "info" => {
                self.info();
            }
            "install" => {
               if args.len() < 1 {
                    match cwd_to_workspace() {
                        None if self.context.use_rust_path_hack => {
                            let cwd = os::getcwd();
                            let inferred_pkgid =
                                PkgId::new(cwd.components[cwd.components.len() - 1]);
                            self.install(PkgSrc::new(cwd, true, inferred_pkgid));
                        }
                        None  => { usage::install(); return; }
                        Some((ws, pkgid))                => {
                            let pkg_src = PkgSrc::new(ws, false, pkgid);
                            self.install(pkg_src);
                      }
                  }
                }
                else {
                    // The package id is presumed to be the first command-line
                    // argument
                    let pkgid = PkgId::new(args[0]);
                    let workspaces = pkg_parent_workspaces(&self.context, &pkgid);
                    debug!("package ID = %s, found it in %? workspaces",
                           pkgid.to_str(), workspaces.len());
                    if workspaces.is_empty() {
                        let rp = rust_path();
                        assert!(!rp.is_empty());
                        let src = PkgSrc::new(rp[0].clone(), false, pkgid.clone());
                        self.install(src);
                    }
                    else {
                        for workspace in workspaces.iter() {
                            let src = PkgSrc::new(workspace.clone(),
                                                  self.context.use_rust_path_hack,
                                                  pkgid.clone());
                            self.install(src);
                        };
                    }
                }
            }
            "list" => {
                io::println("Installed packages:");
                do installed_packages::list_installed_packages |pkg_id| {
                    println(pkg_id.path.to_str());
                    true
                };
            }
            "prefer" => {
                if args.len() < 1 {
                    return usage::uninstall();
                }

                self.prefer(args[0], None);
            }
            "test" => {
                self.test();
            }
            "init" => {
                if args.len() != 0 {
                    return usage::init();
                } else {
                    self.init();
                }
            }
            "uninstall" => {
                if args.len() < 1 {
                    return usage::uninstall();
                }

                let pkgid = PkgId::new(args[0]);
                if !installed_packages::package_is_installed(&pkgid) {
                    warn(fmt!("Package %s doesn't seem to be installed! Doing nothing.", args[0]));
                    return;
                }
                else {
                    let rp = rust_path();
                    assert!(!rp.is_empty());
                    do each_pkg_parent_workspace(&self.context, &pkgid) |workspace| {
                        path_util::uninstall_package_from(workspace, &pkgid);
                        note(fmt!("Uninstalled package %s (was installed in %s)",
                                  pkgid.to_str(), workspace.to_str()));
                        true
                    };
                }
            }
            "unprefer" => {
                if args.len() < 1 {
                    return usage::unprefer();
                }

                self.unprefer(args[0], None);
            }
            _ => fail!(fmt!("I don't know the command `%s`", cmd))
        }
    }

    fn do_cmd(&self, _cmd: &str, _pkgname: &str)  {
        // stub
        fail!("`do` not yet implemented");
    }

    /// Returns the destination workspace
    /// In the case of a custom build, we don't know, so we just return the source workspace
    fn build(&self, exec: &mut workcache::Exec, mut pkg_src: PkgSrc) -> Path {
        let workspace = pkg_src.workspace.clone();
        let pkgid = pkg_src.id.clone();

        debug!("build: workspace = %s (in Rust path? %? is git dir? %? \
                pkgid = %s pkgsrc start_dir = %s", workspace.to_str(),
               in_rust_path(&workspace), is_git_dir(&workspace.push_rel(&pkgid.path)),
               pkgid.to_str(), pkg_src.start_dir.to_str());

        // If workspace isn't in the RUST_PATH, and it's a git repo,
        // then clone it into the first entry in RUST_PATH, and repeat
        if !in_rust_path(&workspace) && is_git_dir(&workspace.push_rel(&pkgid.path)) {
            let out_dir = default_workspace().push("src").push_rel(&pkgid.path);
            source_control::git_clone(&workspace.push_rel(&pkgid.path),
                                      &out_dir, &pkgid.version);
            let default_ws = default_workspace();
            debug!("Calling build recursively with %? and %?", default_ws.to_str(),
                   pkgid.to_str());
            return self.build(exec, PkgSrc::new(default_ws, false, pkgid.clone()));
        }

        // Is there custom build logic? If so, use it
        let mut custom = false;
        debug!("Package source directory = %s", pkg_src.to_str());
        let opt = pkg_src.package_script_option();
        debug!("Calling pkg_script_option on %?", opt);
        let cfgs = match pkg_src.package_script_option() {
            Some(package_script_path) => {
                let sysroot = self.sysroot_to_use();
                let (cfgs, hook_result) = {
                    let pscript = PkgScript::parse(@sysroot.clone(),
                                                   package_script_path.clone(),
                                                   &workspace.clone(),
                                                   &pkgid);
                    pscript.run_custom(exec, &sysroot)
                };
                debug!("Command return code = %?", hook_result);
                if hook_result != 0 {
                    fail!("Error running custom build command")
                }
                custom = true;
                // otherwise, the package script succeeded
                cfgs
            }
            None => {
                debug!("No package script, continuing");
                ~[]
            }
        } + self.context.cfgs;

        // If there was a package script, it should have finished
        // the build already. Otherwise...
        if !custom {
            // Find crates inside the workspace
            pkg_src.find_crates();
            // Build it!
            let rs_path = pkg_src.build(exec, self, cfgs);
            Path(rs_path)
        }
        else {
            // Just return the source workspace
            workspace.clone()
        }
    }

    fn clean(&self, workspace: &Path, id: &PkgId)  {
        // Could also support a custom build hook in the pkg
        // script for cleaning files rustpkg doesn't know about.
        // Do something reasonable for now

        let dir = build_pkg_id_in_workspace(id, workspace);
        note(fmt!("Cleaning package %s (removing directory %s)",
                        id.to_str(), dir.to_str()));
        if os::path_exists(&dir) {
            os::remove_dir_recursive(&dir);
            note(fmt!("Removed directory %s", dir.to_str()));
        }

        note(fmt!("Cleaned package %s", id.to_str()));
    }

    fn info(&self) {
        // stub
        fail!("info not yet implemented");
    }

    fn install(&self, pkg_src: PkgSrc) -> (~[Path], ~[(~str, ~str)]) {

        let id = &pkg_src.id;

        let installed_files = RWArc::new(~[]);
        let inputs = RWArc::new(~[]);
        // FIXME #7402: Use RUST_PATH to determine target dir
        self.workcache_context.with_prep(id.to_str(), |p| pkg_src.declare_inputs(p));
        do self.workcache_context.with_prep(id.to_str()) |prep| {
            let sub_inputs = inputs.clone();
            let sub_files  = installed_files.clone();
            let subsrc = pkg_src.clone();
            let subself = self.clone();
            let id_str = id.to_str();
            let sub_id = id.clone();
            sub_inputs.write(|r| *r = prep.lookup_declared_inputs().map(|v|
                                          { (~"file", (*v).clone()) }));
            do prep.exec |exec| {
                let destination_workspace = subself.build(exec, subsrc.clone()).to_str();
                // See #7402: This still isn't quite right yet; we want to
                // install to the first workspace in the RUST_PATH if there's
                // a non-default RUST_PATH. This code installs to the same
                // workspace the package was built in.
                let actual_workspace = if path_util::user_set_rust_path() {
                    default_workspace()
                }
                else {
                    Path(destination_workspace)
                };
                debug!("install: destination workspace = %s, id = %s, installing to %s",
                       destination_workspace, id_str, actual_workspace.to_str());
                let result = subself.install_no_build(&Path(destination_workspace),
                                                      &actual_workspace,
                                                      &sub_id);
                debug!("install: id = %s, about to call discover_outputs, %?",
                       id_str, result.to_str());

                discover_outputs(exec, result.clone());
                sub_files.write(|r| { *r = result.clone(); });
                sub_inputs.write(|r| { *r = *r + exec.lookup_discovered_inputs() });
                note(fmt!("Installed package %s to %s", id_str, actual_workspace.to_str()));
            }
        };
        (installed_files.unwrap(), inputs.unwrap())
    }

    fn install_no_build(&self,
                        source_workspace: &Path,
                        target_workspace: &Path,
                        id: &PkgId) -> ~[Path] {
        use conditions::copy_failed::cond;

        // Now copy stuff into the install dirs
        let maybe_executable = built_executable_in_workspace(id, source_workspace);
        let maybe_library = built_library_in_workspace(id, source_workspace);
        let target_exec = target_executable_in_workspace(id, target_workspace);
        let target_lib = maybe_library.map(|_p| target_library_in_workspace(id, target_workspace));

        debug!("target_exec = %s target_lib = %? \
                maybe_executable = %? maybe_library = %?",
               target_exec.to_str(), target_lib,
               maybe_executable, maybe_library);

        let mut outputs = ~[];

        for exec in maybe_executable.iter() {
            debug!("Copying: %s -> %s", exec.to_str(), target_exec.to_str());
            if !(os::mkdir_recursive(&target_exec.dir_path(), U_RWX) &&
                 os::copy_file(exec, &target_exec)) {
                cond.raise(((*exec).clone(), target_exec.clone()));
            }
            outputs.push(target_exec.clone());
        }
        for lib in maybe_library.iter() {
            let target_lib = target_lib.clone().expect(fmt!("I built %s but apparently \
                                                didn't install it!", lib.to_str()));
            let target_lib = target_lib.pop().push(lib.filename().expect("weird target lib"));
            debug!("Copying: %s -> %s", lib.to_str(), target_lib.to_str());
            if !(os::mkdir_recursive(&target_lib.dir_path(), U_RWX) &&
                 os::copy_file(lib, &target_lib)) {
                cond.raise(((*lib).clone(), target_lib.clone()));
            }
            outputs.push(target_lib.clone());
        }
        outputs
    }

    fn prefer(&self, _id: &str, _vers: Option<~str>)  {
        fail!("prefer not yet implemented");
    }

    fn test(&self)  {
        // stub
        fail!("test not yet implemented");
    }

    fn init(&self) {
        os::mkdir_recursive(&Path("src"),   U_RWX);
        os::mkdir_recursive(&Path("lib"),   U_RWX);
        os::mkdir_recursive(&Path("bin"),   U_RWX);
        os::mkdir_recursive(&Path("build"), U_RWX);
    }

    fn uninstall(&self, _id: &str, _vers: Option<~str>)  {
        fail!("uninstall not yet implemented");
    }

    fn unprefer(&self, _id: &str, _vers: Option<~str>)  {
        fail!("unprefer not yet implemented");
    }
}

pub fn main() {
    io::println("WARNING: The Rust package manager is experimental and may be unstable");
    let args = os::args();
    main_args(args);
}

pub fn main_args(args: &[~str]) {
    let opts = ~[getopts::optflag("h"), getopts::optflag("help"),
                                        getopts::optflag("no-link"),
                                        getopts::optflag("no-trans"),
                 // n.b. Ignores different --pretty options for now
                                        getopts::optflag("pretty"),
                                        getopts::optflag("parse-only"),
                 getopts::optflag("S"), getopts::optflag("assembly"),
                 getopts::optmulti("c"), getopts::optmulti("cfg"),
                 getopts::optflag("v"), getopts::optflag("version"),
                 getopts::optflag("r"), getopts::optflag("rust-path-hack"),
                                        getopts::optopt("sysroot"),
                                        getopts::optflag("emit-llvm"),
                                        getopts::optopt("linker"),
                                        getopts::optopt("link-args"),
                                        getopts::optopt("opt-level"),
                 getopts::optflag("O"),
                                        getopts::optflag("save-temps"),
                                        getopts::optopt("target"),
                                        getopts::optopt("target-cpu"),
                 getopts::optmulti("Z")                                   ];
    let matches = &match getopts::getopts(args, opts) {
        result::Ok(m) => m,
        result::Err(f) => {
            error(fmt!("%s", getopts::fail_str(f)));

            return;
        }
    };
    let mut help = getopts::opt_present(matches, "h") ||
                   getopts::opt_present(matches, "help");
    let no_link = getopts::opt_present(matches, "no-link");
    let no_trans = getopts::opt_present(matches, "no-trans");
    let supplied_sysroot = getopts::opt_val(matches, "sysroot");
    let generate_asm = getopts::opt_present(matches, "S") ||
        getopts::opt_present(matches, "assembly");
    let parse_only = getopts::opt_present(matches, "parse-only");
    let pretty = getopts::opt_present(matches, "pretty");
    let emit_llvm = getopts::opt_present(matches, "emit-llvm");

    if getopts::opt_present(matches, "v") ||
       getopts::opt_present(matches, "version") {
        rustc::version(args[0]);
        return;
    }

    let use_rust_path_hack = getopts::opt_present(matches, "r") ||
                             getopts::opt_present(matches, "rust-path-hack");

    let linker = getopts::opt_maybe_str(matches, "linker");
    let link_args = getopts::opt_maybe_str(matches, "link-args");
    let cfgs = getopts::opt_strs(matches, "cfg") + getopts::opt_strs(matches, "c");
    let mut user_supplied_opt_level = true;
    let opt_level = match getopts::opt_maybe_str(matches, "opt-level") {
        Some(~"0") => session::No,
        Some(~"1") => session::Less,
        Some(~"2") => session::Default,
        Some(~"3") => session::Aggressive,
        _ if getopts::opt_present(matches, "O") => session::Default,
        _ => {
            user_supplied_opt_level = false;
            session::No
        }
    };

    let save_temps = getopts::opt_present(matches, "save-temps");
    let target     = getopts::opt_maybe_str(matches, "target");
    let target_cpu = getopts::opt_maybe_str(matches, "target-cpu");
    let experimental_features = {
        let strs = getopts::opt_strs(matches, "Z");
        if getopts::opt_present(matches, "Z") {
            Some(strs)
        }
        else {
            None
        }
    };

    let mut args = matches.free.clone();
    args.shift();

    if (args.len() < 1) {
        return usage::general();
    }

    let rustc_flags = RustcFlags {
        linker: linker,
        link_args: link_args,
        optimization_level: opt_level,
        compile_upto: if no_trans {
            Trans
        } else if no_link {
            Link
        } else if pretty {
            Pretty
        } else if parse_only {
            Analysis
        } else if emit_llvm && generate_asm {
            LLVMAssemble
        } else if generate_asm {
            Assemble
        } else if emit_llvm {
            LLVMCompileBitcode
        } else {
            Nothing
        },
        save_temps: save_temps,
        target: target,
        target_cpu: target_cpu,
        experimental_features: experimental_features
    };

    let mut cmd_opt = None;
    for a in args.iter() {
        if util::is_cmd(*a) {
            cmd_opt = Some(a);
            break;
        }
    }
    let cmd = match cmd_opt {
        None => return usage::general(),
        Some(cmd) => {
            help |= context::flags_ok_for_cmd(&rustc_flags, cfgs, *cmd, user_supplied_opt_level);
            if help {
                return match *cmd {
                    ~"build" => usage::build(),
                    ~"clean" => usage::clean(),
                    ~"do" => usage::do_cmd(),
                    ~"info" => usage::info(),
                    ~"install" => usage::install(),
                    ~"list"    => usage::list(),
                    ~"prefer" => usage::prefer(),
                    ~"test" => usage::test(),
                    ~"init" => usage::init(),
                    ~"uninstall" => usage::uninstall(),
                    ~"unprefer" => usage::unprefer(),
                    _ => usage::general()
                };
            } else {
                cmd
            }
        }
    };

    // Pop off all flags, plus the command
    let remaining_args = args.iter().skip_while(|s| !util::is_cmd(**s));
    // I had to add this type annotation to get the code to typecheck
    let mut remaining_args: ~[~str] = remaining_args.map(|s| (*s).clone()).collect();
    remaining_args.shift();
    let sroot = match supplied_sysroot {
        Some(getopts::Val(s)) => Path(s),
        _ => filesearch::get_or_default_sysroot()
    };

    debug!("Using sysroot: %s", sroot.to_str());
    debug!("Will store workcache in %s", default_workspace().to_str());
    BuildContext {
        context: Context {
        cfgs: cfgs,
        rustc_flags: rustc_flags,
        use_rust_path_hack: use_rust_path_hack,
        sysroot: sroot, // Currently, only tests override this
    },
        workcache_context: api::default_context(default_workspace()).workcache_context
    }.run(*cmd, remaining_args)
}

/**
 * Get the working directory of the package script.
 * Assumes that the package script has been compiled
 * in is the working directory.
 */
pub fn work_dir() -> Path {
    os::self_exe_path().unwrap()
}

/**
 * Get the source directory of the package (i.e.
 * where the crates are located). Assumes
 * that the cwd is changed to it before
 * running this executable.
 */
pub fn src_dir() -> Path {
    os::getcwd()
}

fn declare_package_script_dependency(prep: &mut workcache::Prep, pkg_src: &PkgSrc) {
    match pkg_src.package_script_option() {
        Some(ref p) => prep.declare_input("file", p.to_str(),
                                      workcache_support::digest_file_with_date(p)),
        None => ()
    }
}