sysroot.rs

use std::collections::BTreeMap;
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};
use std::path::PathBuf;
use std::process::Command;

use rustc_version::VersionMeta;
use tempdir::TempDir;
use toml::{Table, Value};

use CompilationMode;
use cargo::{Root, Rustflags};
use errors::*;
use extensions::CommandExt;
use rustc::{Src, Sysroot};
use util;
use xargo::Home;
use {cargo, xargo};

#[cfg(feature = "dev")]
fn profile() -> &'static str {
    "debug"
}

#[cfg(not(feature = "dev"))]
fn profile() -> &'static str {
    "release"
}

fn build(
    cmode: &CompilationMode,
    blueprint: Blueprint,
    ctoml: &cargo::Toml,
    home: &Home,
    rustflags: &Rustflags,
    hash: u64,
    verbose: bool,
) -> Result<()> {
    const TOML: &'static str = r#"
[package]
authors = ["The Rust Project Developers"]
name = "sysroot"
version = "0.0.0"
"#;

    let rustlib = home.lock_rw(cmode.triple())?;
    rustlib.remove_siblings().chain_err(|| {
            format!("couldn't clear {}", rustlib.path().display())
        })?;
    let dst = rustlib.parent().join("lib");
    util::mkdir(&dst)?;
    for (_, stage) in blueprint.stages {
        let td = TempDir::new("xargo").chain_err(
            || "couldn't create a temporary directory",
        )?;
        let td = td.path();

        let mut stoml = TOML.to_owned();

        let mut map = Table::new();
        map.insert("dependencies".to_owned(), Value::Table(stage.toml));
        stoml.push_str(&Value::Table(map).to_string());

        if let Some(profile) = ctoml.profile() {
            stoml.push_str(&profile.to_string())
        }

        util::write(&td.join("Cargo.toml"), &stoml)?;
        util::mkdir(&td.join("src"))?;
        util::write(&td.join("src/lib.rs"), "")?;

        let cargo = || {
            let mut cmd = Command::new("cargo");
            let mut flags = rustflags.for_xargo(home);
            flags.push_str(" -Z force-unstable-if-unmarked");
            cmd.env("RUSTFLAGS", flags);
            cmd.env_remove("CARGO_TARGET_DIR");
            cmd.arg("build");

            match () {
                #[cfg(feature = "dev")]
                () => {}
                #[cfg(not(feature = "dev"))]
                () => {
                    cmd.arg("--release");
                }
            }
            cmd.arg("--manifest-path");
            cmd.arg(td.join("Cargo.toml"));
            cmd.args(&["--target", cmode.triple()]);

            if verbose {
                cmd.arg("-v");
            }

            cmd
        };

        for krate in stage.crates {
            cargo().arg("-p").arg(krate).run(verbose)?;
        }

        // Copy artifacts to Xargo sysroot
        util::cp_r(
            &td.join("target")
                .join(cmode.triple())
                .join(profile())
                .join("deps"),
            &dst,
        )?;

    }

    // Create hash file
    util::write(&rustlib.parent().join(".hash"), &hash.to_string())?;

    Ok(())
}

fn old_hash(cmode: &CompilationMode, home: &Home) -> Result<Option<u64>> {
    // FIXME this should be `lock_ro`
    let lock = home.lock_rw(cmode.triple())?;
    let hfile = lock.parent().join(".hash");

    if hfile.exists() {
        Ok(util::read(&hfile)?.parse().ok())
    } else {
        Ok(None)
    }
}

/// Computes the hash of the would-be target sysroot
///
/// This information is used to compute the hash
///
/// - Dependencies in `Xargo.toml` for a specific target
/// - RUSTFLAGS / build.rustflags / target.*.rustflags
/// - The target specification file, is any
/// - `[profile.release]` in `Cargo.toml`
/// - `rustc` commit hash
fn hash(
    cmode: &CompilationMode,
    blueprint: &Blueprint,
    rustflags: &Rustflags,
    ctoml: &cargo::Toml,
    meta: &VersionMeta,
) -> Result<u64> {
    let mut hasher = DefaultHasher::new();

    blueprint.hash(&mut hasher);

    rustflags.hash(&mut hasher);

    cmode.hash(&mut hasher)?;

    if let Some(profile) = ctoml.profile() {
        profile.hash(&mut hasher);
    }

    if let Some(ref hash) = meta.commit_hash {
        hash.hash(&mut hasher);
    }

    Ok(hasher.finish())
}

pub fn update(
    cmode: &CompilationMode,
    home: &Home,
    root: &Root,
    rustflags: &Rustflags,
    meta: &VersionMeta,
    src: &Src,
    sysroot: &Sysroot,
    verbose: bool,
) -> Result<()> {
    let ctoml = cargo::toml(root)?;
    let xtoml = xargo::toml(root)?;

    let blueprint =
        Blueprint::from(xtoml.as_ref(), cmode.triple(), root, &src)?;

    let hash = hash(cmode, &blueprint, rustflags, &ctoml, meta)?;

    if old_hash(cmode, home)? != Some(hash) {
        build(cmode, blueprint, &ctoml, home, rustflags, hash, verbose)?;
    }

    // copy host artifacts into the sysroot, if necessary
    if cmode.is_native() {
        return Ok(());
    }

    let lock = home.lock_rw(&meta.host)?;
    let hfile = lock.parent().join(".hash");

    let hash = meta.commit_hash.as_ref().map(|s| &**s).unwrap_or("");
    if hfile.exists() {
        if util::read(&hfile)? == hash {
            return Ok(());
        }
    }

    lock.remove_siblings().chain_err(|| {
            format!("couldn't clear {}", lock.path().display())
        })?;
    let dst = lock.parent().join("lib");
    util::mkdir(&dst)?;
    util::cp_r(
        &sysroot.path().join("lib/rustlib").join(&meta.host).join(
            "lib",
        ),
        &dst,
    )?;

    util::write(&hfile, hash)?;

    Ok(())
}

/// Per stage dependencies
#[derive(Debug)]
pub struct Stage {
    crates: Vec<String>,
    toml: Table,
}

/// A sysroot that will be built in "stages"
#[derive(Debug)]
pub struct Blueprint {
    stages: BTreeMap<i64, Stage>,
}

impl Blueprint {
    fn new() -> Self {
        Blueprint { stages: BTreeMap::new() }
    }

    fn from(
        toml: Option<&xargo::Toml>,
        target: &str,
        root: &Root,
        src: &Src,
    ) -> Result<Self> {
        let deps = match (
            toml.and_then(|t| t.dependencies()),
            toml.and_then(|t| t.target_dependencies(target)),
        ) {
            (Some(value), Some(tvalue)) => {
                let mut deps = value.as_table().cloned().ok_or_else(
                    || format!("Xargo.toml: `dependencies` must be a table"),
                )?;

                let more_deps = tvalue.as_table().ok_or_else(|| {
                    format!(
                        "Xargo.toml: `target.{}.dependencies` must be \
                                 a table",
                        target
                    )
                })?;
                for (k, v) in more_deps {
                    if deps.insert(k.to_owned(), v.clone()).is_some() {
                        Err(format!(
                            "found duplicate dependency name {}, \
                                     but all dependencies must have a \
                                     unique name",
                            k
                        ))?
                    }
                }

                deps
            }
            (Some(value), None) |
            (None, Some(value)) => {
                if let Some(table) = value.as_table() {
                    table.clone()
                } else {
                    Err(format!(
                        "Xargo.toml: target.{}.dependencies must be \
                                 a table",
                        target
                    ))?
                }
            }
            (None, None) => {
                // If no dependencies were listed, we assume `core` as the
                // only dependency
                let mut t = BTreeMap::new();
                t.insert("core".to_owned(), Value::Table(BTreeMap::new()));
                t
            }
        };

        let mut blueprint = Blueprint::new();
        for (k, v) in deps {
            if let Value::Table(mut map) = v {
                let stage = if let Some(value) = map.remove("stage") {
                    value.as_integer().ok_or_else(|| {
                            format!(
                                "dependencies.{}.stage must be an integer",
                                k
                            )
                        })?
                } else {
                    0
                };

                if let Some(path) = map.get_mut("path") {
                    let p = PathBuf::from(
                        path.as_str().ok_or_else(|| {
                                format!(
                                    "dependencies.{}.path must be a string",
                                    k
                                )
                            })?,
                    );

                    if !p.is_absolute() {
                        *path = Value::String(
                            root.path()
                                .join(&p)
                                .canonicalize()
                                .chain_err(|| {
                                        format!(
                                            "couldn't canonicalize {}",
                                            p.display()
                                        )
                                    })?
                                .display()
                                .to_string(),
                        );
                    }
                }

                if !map.contains_key("path") && !map.contains_key("git") {
                    let path = src.path()
                        .join(format!("lib{}", k))
                        .display()
                        .to_string();

                    map.insert("path".to_owned(), Value::String(path));
                }

                blueprint.push(stage, k, map);
            } else {
                Err(format!(
                    "Xargo.toml: target.{}.dependencies.{} must be \
                             a table",
                    target,
                    k
                ))?
            }
        }

        Ok(blueprint)
    }

    fn push(&mut self, stage: i64, krate: String, toml: Table) {
        let stage = self.stages.entry(stage).or_insert_with(|| {
            Stage {
                crates: vec![],
                toml: Table::new(),
            }
        });

        stage.toml.insert(krate.clone(), Value::Table(toml));
        stage.crates.push(krate);
    }

    fn hash<H>(&self, hasher: &mut H)
    where
        H: Hasher,
    {
        for stage in self.stages.values() {
            for (k, v) in stage.toml.iter() {
                k.hash(hasher);
                v.to_string().hash(hasher);
            }
        }
    }
}