#
cargo/core/compiler/
standard_lib.rs

    1//! Code for building the standard library.
    2
    3use crate::core::compiler::UnitInterner;
    4use crate::core::compiler::unit_dependencies::IsArtifact;
    5use crate::core::compiler::{CompileKind, CompileMode, RustcTargetData, Unit};
    6use crate::core::profiles::{Profiles, UnitFor};
    7use crate::core::resolver::HasDevUnits;
    8use crate::core::resolver::features::{CliFeatures, FeaturesFor, ResolvedFeatures};
    9use crate::core::{PackageId, PackageSet, Resolve, Workspace};
    10use crate::ops::{self, Packages};
    11use crate::util::errors::CargoResult;
    12
    13use std::collections::{HashMap, HashSet};
    14use std::path::PathBuf;
    15
    16use super::BuildConfig;
    17
    18fn std_crates<'a>(crates: &'a [String], default: &'static str, units: &[Unit]) -> HashSet<&'a str> {
    19    let mut crates = HashSet::from_iter(crates.iter().map(|s| s.as_str()));
    20    // This is a temporary hack until there is a more principled way to
    21    // declare dependencies in Cargo.toml.
    22    if crates.is_empty() {
    23        crates.insert(default);
    24    }
    25    if crates.contains("std") {
    26        crates.insert("core");
    27        crates.insert("alloc");
    28        crates.insert("proc_macro");
    29        crates.insert("panic_unwind");
    30        crates.insert("compiler_builtins");
    31        // Only build libtest if it looks like it is needed (libtest depends on libstd)
    32        // If we know what units we're building, we can filter for libtest depending on the jobs.
    33        if units
    34            .iter()
    35            .any(|unit| unit.mode.is_rustc_test() && unit.target.harness())
    36        {
    37            crates.insert("test");
    38        }
    39    } else if crates.contains("core") {
    40        crates.insert("compiler_builtins");
    41    }
    42
    43    crates
    44}
    45
    46/// Resolve the standard library dependencies.
    47///
    48/// * `crates` is the arg value from `-Zbuild-std`.
    49pub fn resolve_std<'gctx>(
    50    ws: &Workspace<'gctx>,
    51    target_data: &mut RustcTargetData<'gctx>,
    52    build_config: &BuildConfig,
    53    crates: &[String],
    54    kinds: &[CompileKind],
    55) -> CargoResult<(PackageSet<'gctx>, Resolve, ResolvedFeatures)> {
    56    let src_path = detect_sysroot_src_path(target_data)?;
    57    let std_ws_manifest_path = src_path.join("Cargo.toml");
    58    let gctx = ws.gctx();
    59    // TODO: Consider doing something to enforce --locked? Or to prevent the
    60    // lock file from being written, such as setting ephemeral.
    61    let mut std_ws = Workspace::new(&std_ws_manifest_path, gctx)?;
    62    // Don't require optional dependencies in this workspace, aka std's own
    63    // `[dev-dependencies]`. No need for us to generate a `Resolve` which has
    64    // those included because we'll never use them anyway.
    65    std_ws.set_require_optional_deps(false);
    66    let specs = {
    67        // If there is anything looks like needing std, resolve with it.
    68        // If not, we assume only `core` maye be needed, as `core the most fundamental crate.
    69        //
    70        // This may need a UI overhaul if `build-std` wants to fully support multi-targets.
    71        let maybe_std = kinds
    72            .iter()
    73            .any(|kind| target_data.info(*kind).maybe_support_std());
    74        let mut crates = std_crates(crates, if maybe_std { "std" } else { "core" }, &[]);
    75        // `sysroot` is not in the default set because it is optional, but it needs
    76        // to be part of the resolve in case we do need it or `libtest`.
    77        crates.insert("sysroot");
    78        let specs = Packages::Packages(crates.into_iter().map(Into::into).collect());
    79        specs.to_package_id_specs(&std_ws)?
    80    };
    81    let features = match &gctx.cli_unstable().build_std_features {
    82        Some(list) => list.clone(),
    83        None => vec![
    84            "panic-unwind".to_string(),
    85            "backtrace".to_string(),
    86            "default".to_string(),
    87        ],
    88    };
    89    let cli_features = CliFeatures::from_command_line(
    90        &features, /*all_features*/ false, /*uses_default_features*/ false,
    91    )?;
    92    let dry_run = false;
    93    let mut resolve = ops::resolve_ws_with_opts(
    94        &std_ws,
    95        target_data,
    96        &build_config.requested_kinds,
    97        &cli_features,
    98        &specs,
    99        HasDevUnits::No,
    100        crate::core::resolver::features::ForceAllTargets::No,
    101        dry_run,
    102    )?;
    103    debug_assert_eq!(resolve.specs_and_features.len(), 1);
    104    Ok((
    105        resolve.pkg_set,
    106        resolve.targeted_resolve,
    107        resolve
    108            .specs_and_features
    109            .pop()
    110            .expect("resolve should have a single spec with resolved features")
    111            .resolved_features,
    112    ))
    113}
    114
    115/// Generates a map of root units for the standard library for each kind requested.
    116///
    117/// * `crates` is the arg value from `-Zbuild-std`.
    118/// * `units` is the root units of the build.
    119pub fn generate_std_roots(
    120    crates: &[String],
    121    units: &[Unit],
    122    std_resolve: &Resolve,
    123    std_features: &ResolvedFeatures,
    124    kinds: &[CompileKind],
    125    package_set: &PackageSet<'_>,
    126    interner: &UnitInterner,
    127    profiles: &Profiles,
    128    target_data: &RustcTargetData<'_>,
    129) -> CargoResult<HashMap<CompileKind, Vec<Unit>>> {
    130    // Generate a map of Units for each kind requested.
    131    let mut ret = HashMap::new();
    132    let (maybe_std, maybe_core): (Vec<&CompileKind>, Vec<_>) = kinds
    133        .iter()
    134        .partition(|kind| target_data.info(**kind).maybe_support_std());
    135    for (default_crate, kinds) in [("core", maybe_core), ("std", maybe_std)] {
    136        if kinds.is_empty() {
    137            continue;
    138        }
    139        generate_roots(
    140            &mut ret,
    141            default_crate,
    142            crates,
    143            units,
    144            std_resolve,
    145            std_features,
    146            &kinds,
    147            package_set,
    148            interner,
    149            profiles,
    150            target_data,
    151        )?;
    152    }
    153
    154    Ok(ret)
    155}
    156
    157fn generate_roots(
    158    ret: &mut HashMap<CompileKind, Vec<Unit>>,
    159    default: &'static str,
    160    crates: &[String],
    161    units: &[Unit],
    162    std_resolve: &Resolve,
    163    std_features: &ResolvedFeatures,
    164    kinds: &[&CompileKind],
    165    package_set: &PackageSet<'_>,
    166    interner: &UnitInterner,
    167    profiles: &Profiles,
    168    target_data: &RustcTargetData<'_>,
    169) -> CargoResult<()> {
    170    let std_ids = std_crates(crates, default, units)
    171        .iter()
    172        .map(|crate_name| std_resolve.query(crate_name))
    173        .collect::<CargoResult<Vec<PackageId>>>()?;
    174    let std_pkgs = package_set.get_many(std_ids)?;
    175
    176    for pkg in std_pkgs {
    177        let lib = pkg
    178            .targets()
    179            .iter()
    180            .find(|t| t.is_lib())
    181            .expect("std has a lib");
    182        // I don't think we need to bother with Check here, the difference
    183        // in time is minimal, and the difference in caching is
    184        // significant.
    185        let mode = CompileMode::Build;
    186        let features = std_features.activated_features(pkg.package_id(), FeaturesFor::NormalOrDev);
    187        for kind in kinds {
    188            let kind = **kind;
    189            let list = ret.entry(kind).or_insert_with(Vec::new);
    190            let unit_for = UnitFor::new_normal(kind);
    191            let profile = profiles.get_profile(
    192                pkg.package_id(),
    193                /*is_member*/ false,
    194                /*is_local*/ false,
    195                unit_for,
    196                kind,
    197            );
    198            list.push(interner.intern(
    199                pkg,
    200                lib,
    201                profile,
    202                kind,
    203                mode,
    204                features.clone(),
    205                target_data.info(kind).rustflags.clone(),
    206                target_data.info(kind).rustdocflags.clone(),
    207                target_data.target_config(kind).links_overrides.clone(),
    208                /*is_std*/ true,
    209                /*dep_hash*/ 0,
    210                IsArtifact::No,
    211                None,
    212                false,
    213            ));
    214        }
    215    }
    216    Ok(())
    217}
    218
    219fn detect_sysroot_src_path(target_data: &RustcTargetData<'_>) -> CargoResult<PathBuf> {
    220    if let Some(s) = target_data.gctx.get_env_os("__CARGO_TESTS_ONLY_SRC_ROOT") {
    221        return Ok(s.into());
    222    }
    223
    224    // NOTE: This is temporary until we figure out how to acquire the source.
    225    let src_path = target_data
    226        .info(CompileKind::Host)
    227        .sysroot
    228        .join("lib")
    229        .join("rustlib")
    230        .join("src")
    231        .join("rust")
    232        .join("library");
    233    let lock = src_path.join("Cargo.lock");
    234    if !lock.exists() {
    235        let msg = format!(
    236            "{:?} does not exist, unable to build with the standard \
    237             library, try:\n        rustup component add rust-src",
    238            lock
    239        );
    240        match target_data.gctx.get_env("RUSTUP_TOOLCHAIN") {
    241            Ok(rustup_toolchain) => {
    242                anyhow::bail!("{} --toolchain {}", msg, rustup_toolchain);
    243            }
    244            Err(_) => {
    245                anyhow::bail!(msg);
    246            }
    247        }
    248    }
    249    Ok(src_path)
    250}