#
cargo/ops/
resolve.rs

    1//! High-level APIs for executing the resolver.
    2//!
    3//! This module provides functions for running the resolver given a workspace, including loading
    4//! the `Cargo.lock` file and checking if it needs updating.
    5//!
    6//! There are roughly 3 main functions:
    7//!
    8//! - [`resolve_ws`]: A simple, high-level function with no options.
    9//! - [`resolve_ws_with_opts`]: A medium-level function with options like
    10//!   user-provided features. This is the most appropriate function to use in
    11//!   most cases.
    12//! - [`resolve_with_previous`]: A low-level function for running the resolver,
    13//!   providing the most power and flexibility.
    14//!
    15//! ### Data Structures
    16//!
    17//! - [`Workspace`]:
    18//!   Usually created by [`crate::util::command_prelude::ArgMatchesExt::workspace`] which discovers the root of the
    19//!   workspace, and loads all the workspace members as a [`Package`] object
    20//!   - [`Package`]
    21//!     Corresponds with `Cargo.toml` manifest (deserialized as [`Manifest`]) and its associated files.
    22//!     - [`Target`]s are crates such as the library, binaries, integration test, or examples.
    23//!       They are what is actually compiled by `rustc`.
    24//!       Each `Target` defines a crate root, like `src/lib.rs` or `examples/foo.rs`.
    25//!     - [`PackageId`] --- A unique identifier for a package.
    26//! - [`PackageRegistry`]:
    27//!   The primary interface for how the dependency
    28//!   resolver finds packages. It contains the `SourceMap`, and handles things
    29//!   like the `[patch]` table. The dependency resolver
    30//!   sends a query to the `PackageRegistry` to "get me all packages that match
    31//!   this dependency declaration". The `Registry` trait provides a generic interface
    32//!   to the `PackageRegistry`, but this is only used for providing an alternate
    33//!   implementation of the `PackageRegistry` for testing.
    34//! - [`SourceMap`]: Map of all available sources.
    35//!   - [`Source`]: An abstraction for something that can fetch packages (a remote
    36//!     registry, a git repo, the local filesystem, etc.). Check out the [source
    37//!     implementations] for all the details about registries, indexes, git
    38//!     dependencies, etc.
    39//!       * [`SourceId`]: A unique identifier for a source.
    40//!   - [`Summary`]: A of a [`Manifest`], and is essentially
    41//!     the information that can be found in a registry index. Queries against the
    42//!     `PackageRegistry` yields a `Summary`. The resolver uses the summary
    43//!     information to build the dependency graph.
    44//! - [`PackageSet`] --- Contains all the `Package` objects. This works with the
    45//!   [`Downloads`] struct to coordinate downloading packages. It has a reference
    46//!   to the `SourceMap` to get the `Source` objects which tell the `Downloads`
    47//!   struct which URLs to fetch.
    48//!
    49//! [`Package`]: crate::core::package
    50//! [`Target`]: crate::core::Target
    51//! [`Manifest`]: crate::core::Manifest
    52//! [`Source`]: crate::sources::source::Source
    53//! [`SourceMap`]: crate::sources::source::SourceMap
    54//! [`PackageRegistry`]: crate::core::registry::PackageRegistry
    55//! [source implementations]: crate::sources
    56//! [`Downloads`]: crate::core::package::Downloads
    57
    58use crate::core::Dependency;
    59use crate::core::GitReference;
    60use crate::core::PackageId;
    61use crate::core::PackageIdSpec;
    62use crate::core::PackageIdSpecQuery;
    63use crate::core::PackageSet;
    64use crate::core::SourceId;
    65use crate::core::Workspace;
    66use crate::core::compiler::{CompileKind, RustcTargetData};
    67use crate::core::registry::{LockedPatchDependency, PackageRegistry};
    68use crate::core::resolver::features::{
    69    CliFeatures, FeatureOpts, FeatureResolver, ForceAllTargets, RequestedFeatures, ResolvedFeatures,
    70};
    71use crate::core::resolver::{
    72    self, HasDevUnits, Resolve, ResolveOpts, ResolveVersion, VersionOrdering, VersionPreferences,
    73};
    74use crate::core::summary::Summary;
    75use crate::ops;
    76use crate::sources::RecursivePathSource;
    77use crate::util::CanonicalUrl;
    78use crate::util::cache_lock::CacheLockMode;
    79use crate::util::context::FeatureUnification;
    80use crate::util::errors::CargoResult;
    81use anyhow::Context as _;
    82use cargo_util::paths;
    83use cargo_util_schemas::core::PartialVersion;
    84use std::borrow::Cow;
    85use std::collections::{HashMap, HashSet};
    86use std::rc::Rc;
    87use tracing::{debug, trace};
    88
    89/// Filter for keep using Package ID from previous lockfile.
    90type Keep<'a> = &'a dyn Fn(&PackageId) -> bool;
    91
    92/// Result for `resolve_ws_with_opts`.
    93pub struct WorkspaceResolve<'gctx> {
    94    /// Packages to be downloaded.
    95    pub pkg_set: PackageSet<'gctx>,
    96    /// The resolve for the entire workspace.
    97    ///
    98    /// This may be `None` for things like `cargo install` and `-Zavoid-dev-deps`.
    99    /// This does not include `paths` overrides.
    100    pub workspace_resolve: Option<Resolve>,
    101    /// The narrowed resolve, with the specific features enabled.
    102    pub targeted_resolve: Resolve,
    103    /// Package specs requested for compilation along with specific features enabled. This usually
    104    /// has the length of one but there may be more specs with different features when using the
    105    /// `package` feature resolver.
    106    pub specs_and_features: Vec<SpecsAndResolvedFeatures>,
    107}
    108
    109/// Pair of package specs requested for compilation along with enabled features.
    110pub struct SpecsAndResolvedFeatures {
    111    /// Packages that are supposed to be built.
    112    pub specs: Vec<PackageIdSpec>,
    113    /// The features activated per package.
    114    pub resolved_features: ResolvedFeatures,
    115}
    116
    117const UNUSED_PATCH_WARNING: &str = "\
    118Check that the patched package version and available features are compatible
    119with the dependency requirements. If the patch has a different version from
    120what is locked in the Cargo.lock file, run `cargo update` to use the new
    121version. This may also occur with an optional dependency that is not enabled.";
    122
    123/// Resolves all dependencies for the workspace using the previous
    124/// lock file as a guide if present.
    125///
    126/// This function will also write the result of resolution as a new lock file
    127/// (unless it is an ephemeral workspace such as `cargo install` or `cargo
    128/// package`).
    129///
    130/// This is a simple interface used by commands like `clean`, `fetch`, and
    131/// `package`, which don't specify any options or features.
    132pub fn resolve_ws<'a>(ws: &Workspace<'a>, dry_run: bool) -> CargoResult<(PackageSet<'a>, Resolve)> {
    133    let mut registry = ws.package_registry()?;
    134    let resolve = resolve_with_registry(ws, &mut registry, dry_run)?;
    135    let packages = get_resolved_packages(&resolve, registry)?;
    136    Ok((packages, resolve))
    137}
    138
    139/// Resolves dependencies for some packages of the workspace,
    140/// taking into account `paths` overrides and activated features.
    141///
    142/// This function will also write the result of resolution as a new lock file
    143/// (unless `Workspace::require_optional_deps` is false, such as `cargo
    144/// install` or `-Z avoid-dev-deps`), or it is an ephemeral workspace (`cargo
    145/// install` or `cargo package`).
    146///
    147/// `specs` may be empty, which indicates it should resolve all workspace
    148/// members. In this case, `opts.all_features` must be `true`.
    149pub fn resolve_ws_with_opts<'gctx>(
    150    ws: &Workspace<'gctx>,
    151    target_data: &mut RustcTargetData<'gctx>,
    152    requested_targets: &[CompileKind],
    153    cli_features: &CliFeatures,
    154    specs: &[PackageIdSpec],
    155    has_dev_units: HasDevUnits,
    156    force_all_targets: ForceAllTargets,
    157    dry_run: bool,
    158) -> CargoResult<WorkspaceResolve<'gctx>> {
    159    let feature_unification = ws.resolve_feature_unification();
    160    let individual_specs = match feature_unification {
    161        FeatureUnification::Selected => vec![specs.to_owned()],
    162        FeatureUnification::Workspace => {
    163            vec![ops::Packages::All(Vec::new()).to_package_id_specs(ws)?]
    164        }
    165        FeatureUnification::Package => specs.iter().map(|spec| vec![spec.clone()]).collect(),
    166    };
    167    let specs: Vec<_> = individual_specs
    168        .iter()
    169        .map(|specs| specs.iter())
    170        .flatten()
    171        .cloned()
    172        .collect();
    173    let specs = &specs[..];
    174    let mut registry = ws.package_registry()?;
    175    let (resolve, resolved_with_overrides) = if ws.ignore_lock() {
    176        let add_patches = true;
    177        let resolve = None;
    178        let resolved_with_overrides = resolve_with_previous(
    179            &mut registry,
    180            ws,
    181            cli_features,
    182            has_dev_units,
    183            resolve.as_ref(),
    184            None,
    185            specs,
    186            add_patches,
    187        )?;
    188        ops::print_lockfile_changes(ws, None, &resolved_with_overrides, &mut registry)?;
    189        (resolve, resolved_with_overrides)
    190    } else if ws.require_optional_deps() {
    191        // First, resolve the root_package's *listed* dependencies, as well as
    192        // downloading and updating all remotes and such.
    193        let resolve = resolve_with_registry(ws, &mut registry, dry_run)?;
    194        // No need to add patches again, `resolve_with_registry` has done it.
    195        let add_patches = false;
    196
    197        // Second, resolve with precisely what we're doing. Filter out
    198        // transitive dependencies if necessary, specify features, handle
    199        // overrides, etc.
    200        add_overrides(&mut registry, ws)?;
    201
    202        for (replace_spec, dep) in ws.root_replace() {
    203            if !resolve
    204                .iter()
    205                .any(|r| replace_spec.matches(r) && !dep.matches_id(r))
    206            {
    207                ws.gctx()
    208                    .shell()
    209                    .warn(format!("package replacement is not used: {}", replace_spec))?
    210            }
    211
    212            if dep.features().len() != 0 || !dep.uses_default_features() {
    213                ws.gctx()
    214                .shell()
    215                .warn(format!(
    216                    "replacement for `{}` uses the features mechanism. \
    217                    default-features and features will not take effect because the replacement dependency does not support this mechanism",
    218                    dep.package_name()
    219                ))?
    220            }
    221        }
    222
    223        let resolved_with_overrides = resolve_with_previous(
    224            &mut registry,
    225            ws,
    226            cli_features,
    227            has_dev_units,
    228            Some(&resolve),
    229            None,
    230            specs,
    231            add_patches,
    232        )?;
    233        (Some(resolve), resolved_with_overrides)
    234    } else {
    235        let add_patches = true;
    236        let resolve = ops::load_pkg_lockfile(ws)?;
    237        let resolved_with_overrides = resolve_with_previous(
    238            &mut registry,
    239            ws,
    240            cli_features,
    241            has_dev_units,
    242            resolve.as_ref(),
    243            None,
    244            specs,
    245            add_patches,
    246        )?;
    247        // Skipping `print_lockfile_changes` as there are cases where this prints irrelevant
    248        // information
    249        (resolve, resolved_with_overrides)
    250    };
    251
    252    let pkg_set = get_resolved_packages(&resolved_with_overrides, registry)?;
    253
    254    let members_with_features = ws.members_with_features(specs, cli_features)?;
    255    let member_ids = members_with_features
    256        .iter()
    257        .map(|(p, _fts)| p.package_id())
    258        .collect::<Vec<_>>();
    259    pkg_set.download_accessible(
    260        &resolved_with_overrides,
    261        &member_ids,
    262        has_dev_units,
    263        requested_targets,
    264        target_data,
    265        force_all_targets,
    266    )?;
    267
    268    let mut specs_and_features = Vec::new();
    269
    270    for specs in individual_specs {
    271        let feature_opts = FeatureOpts::new(ws, has_dev_units, force_all_targets)?;
    272
    273        // We want to narrow the features to the current specs so that stuff like `cargo check -p a
    274        // -p b -F a/a,b/b` works and the resolver does not contain that `a` does not have feature
    275        // `b` and vice-versa. However, resolver v1 needs to see even features of unselected
    276        // packages turned on if it was because of working directory being inside the unselected
    277        // package, because they might turn on a feature of a selected package.
    278        let narrowed_features = match feature_unification {
    279            FeatureUnification::Package => {
    280                let mut narrowed_features = cli_features.clone();
    281                let enabled_features = members_with_features
    282                    .iter()
    283                    .filter_map(|(package, cli_features)| {
    284                        specs
    285                            .iter()
    286                            .any(|spec| spec.matches(package.package_id()))
    287                            .then_some(cli_features.features.iter())
    288                    })
    289                    .flatten()
    290                    .cloned()
    291                    .collect();
    292                narrowed_features.features = Rc::new(enabled_features);
    293                Cow::Owned(narrowed_features)
    294            }
    295            FeatureUnification::Selected | FeatureUnification::Workspace => {
    296                Cow::Borrowed(cli_features)
    297            }
    298        };
    299
    300        let resolved_features = FeatureResolver::resolve(
    301            ws,
    302            target_data,
    303            &resolved_with_overrides,
    304            &pkg_set,
    305            &*narrowed_features,
    306            &specs,
    307            requested_targets,
    308            feature_opts,
    309        )?;
    310
    311        pkg_set.warn_no_lib_packages_and_artifact_libs_overlapping_deps(
    312            ws,
    313            &resolved_with_overrides,
    314            &member_ids,
    315            has_dev_units,
    316            requested_targets,
    317            target_data,
    318            force_all_targets,
    319        )?;
    320
    321        specs_and_features.push(SpecsAndResolvedFeatures {
    322            specs,
    323            resolved_features,
    324        });
    325    }
    326
    327    Ok(WorkspaceResolve {
    328        pkg_set,
    329        workspace_resolve: resolve,
    330        targeted_resolve: resolved_with_overrides,
    331        specs_and_features,
    332    })
    333}
    334
    335#[tracing::instrument(skip_all)]
    336fn resolve_with_registry<'gctx>(
    337    ws: &Workspace<'gctx>,
    338    registry: &mut PackageRegistry<'gctx>,
    339    dry_run: bool,
    340) -> CargoResult<Resolve> {
    341    let prev = ops::load_pkg_lockfile(ws)?;
    342    let mut resolve = resolve_with_previous(
    343        registry,
    344        ws,
    345        &CliFeatures::new_all(true),
    346        HasDevUnits::Yes,
    347        prev.as_ref(),
    348        None,
    349        &[],
    350        true,
    351    )?;
    352
    353    let print = if !ws.is_ephemeral() && ws.require_optional_deps() {
    354        if !dry_run {
    355            ops::write_pkg_lockfile(ws, &mut resolve)?
    356        } else {
    357            true
    358        }
    359    } else {
    360        // This mostly represents
    361        // - `cargo install --locked` and the only change is the package is no longer local but
    362        //   from the registry which is noise
    363        // - publish of libraries
    364        false
    365    };
    366    if print {
    367        ops::print_lockfile_changes(ws, prev.as_ref(), &resolve, registry)?;
    368    }
    369    Ok(resolve)
    370}
    371
    372/// Resolves all dependencies for a package using an optional previous instance
    373/// of resolve to guide the resolution process.
    374///
    375/// This also takes an optional filter `keep_previous`, which informs the `registry`
    376/// which package ID should be locked to the previous instance of resolve
    377/// (often used in pairings with updates). See comments in [`register_previous_locks`]
    378/// for scenarios that might override this.
    379///
    380/// The previous resolve normally comes from a lock file. This function does not
    381/// read or write lock files from the filesystem.
    382///
    383/// `specs` may be empty, which indicates it should resolve all workspace
    384/// members. In this case, `opts.all_features` must be `true`.
    385///
    386/// If `register_patches` is true, then entries from the `[patch]` table in
    387/// the manifest will be added to the given `PackageRegistry`.
    388#[tracing::instrument(skip_all)]
    389pub fn resolve_with_previous<'gctx>(
    390    registry: &mut PackageRegistry<'gctx>,
    391    ws: &Workspace<'gctx>,
    392    cli_features: &CliFeatures,
    393    has_dev_units: HasDevUnits,
    394    previous: Option<&Resolve>,
    395    keep_previous: Option<Keep<'_>>,
    396    specs: &[PackageIdSpec],
    397    register_patches: bool,
    398) -> CargoResult<Resolve> {
    399    // We only want one Cargo at a time resolving a crate graph since this can
    400    // involve a lot of frobbing of the global caches.
    401    let _lock = ws
    402        .gctx()
    403        .acquire_package_cache_lock(CacheLockMode::DownloadExclusive)?;
    404
    405    // Some packages are already loaded when setting up a workspace. This
    406    // makes it so anything that was already loaded will not be loaded again.
    407    // Without this there were cases where members would be parsed multiple times
    408    ws.preload(registry);
    409
    410    // In case any members were not already loaded or the Workspace is_ephemeral.
    411    for member in ws.members() {
    412        registry.add_sources(Some(member.package_id().source_id()))?;
    413    }
    414
    415    // Try to keep all from previous resolve if no instruction given.
    416    let keep_previous = keep_previous.unwrap_or(&|_| true);
    417
    418    // While registering patches, we will record preferences for particular versions
    419    // of various packages.
    420    let mut version_prefs = VersionPreferences::default();
    421    if ws.gctx().cli_unstable().minimal_versions {
    422        version_prefs.version_ordering(VersionOrdering::MinimumVersionsFirst)
    423    }
    424    if ws.resolve_honors_rust_version() {
    425        let mut rust_versions: Vec<_> = ws
    426            .members()
    427            .filter_map(|p| p.rust_version().map(|rv| rv.as_partial().clone()))
    428            .collect();
    429        if rust_versions.is_empty() {
    430            let rustc = ws.gctx().load_global_rustc(Some(ws))?;
    431            let rust_version: PartialVersion = rustc.version.clone().into();
    432            rust_versions.push(rust_version);
    433        }
    434        version_prefs.rust_versions(rust_versions);
    435    }
    436
    437    let avoid_patch_ids = if register_patches {
    438        register_patch_entries(registry, ws, previous, &mut version_prefs, keep_previous)?
    439    } else {
    440        HashSet::new()
    441    };
    442
    443    // Refine `keep` with patches that should avoid locking.
    444    let keep = |p: &PackageId| keep_previous(p) && !avoid_patch_ids.contains(p);
    445
    446    let dev_deps = ws.require_optional_deps() || has_dev_units == HasDevUnits::Yes;
    447
    448    if let Some(r) = previous {
    449        trace!("previous: {:?}", r);
    450
    451        // In the case where a previous instance of resolve is available, we
    452        // want to lock as many packages as possible to the previous version
    453        // without disturbing the graph structure.
    454        register_previous_locks(ws, registry, r, &keep, dev_deps);
    455
    456        // Prefer to use anything in the previous lock file, aka we want to have conservative updates.
    457        let _span = tracing::span!(tracing::Level::TRACE, "prefer_package_id").entered();
    458        for id in r.iter().filter(keep) {
    459            debug!("attempting to prefer {}", id);
    460            version_prefs.prefer_package_id(id);
    461        }
    462    }
    463
    464    if register_patches {
    465        registry.lock_patches();
    466    }
    467
    468    let summaries: Vec<(Summary, ResolveOpts)> = {
    469        let _span = tracing::span!(tracing::Level::TRACE, "registry.lock").entered();
    470        ws.members_with_features(specs, cli_features)?
    471            .into_iter()
    472            .map(|(member, features)| {
    473                let summary = registry.lock(member.summary().clone());
    474                (
    475                    summary,
    476                    ResolveOpts {
    477                        dev_deps,
    478                        features: RequestedFeatures::CliFeatures(features),
    479                    },
    480                )
    481            })
    482            .collect()
    483    };
    484
    485    let replace = lock_replacements(ws, previous, &keep);
    486
    487    let mut resolved = resolver::resolve(
    488        &summaries,
    489        &replace,
    490        registry,
    491        &version_prefs,
    492        ResolveVersion::with_rust_version(ws.lowest_rust_version()),
    493        Some(ws.gctx()),
    494    )?;
    495
    496    let patches = registry.patches().values().flat_map(|v| v.iter());
    497    resolved.register_used_patches(patches);
    498
    499    if register_patches && !resolved.unused_patches().is_empty() {
    500        emit_warnings_of_unused_patches(ws, &resolved, registry)?;
    501    }
    502
    503    if let Some(previous) = previous {
    504        resolved.merge_from(previous)?;
    505    }
    506    let gctx = ws.gctx();
    507    let mut deferred = gctx.deferred_global_last_use()?;
    508    deferred.save_no_error(gctx);
    509    Ok(resolved)
    510}
    511
    512/// Read the `paths` configuration variable to discover all path overrides that
    513/// have been configured.
    514#[tracing::instrument(skip_all)]
    515pub fn add_overrides<'a>(
    516    registry: &mut PackageRegistry<'a>,
    517    ws: &Workspace<'a>,
    518) -> CargoResult<()> {
    519    let gctx = ws.gctx();
    520    let Some(paths) = gctx.get_list("paths")? else {
    521        return Ok(());
    522    };
    523
    524    let paths = paths.val.iter().map(|(s, def)| {
    525        // The path listed next to the string is the config file in which the
    526        // key was located, so we want to pop off the `.cargo/config` component
    527        // to get the directory containing the `.cargo` folder.
    528        (paths::normalize_path(&def.root(gctx).join(s)), def)
    529    });
    530
    531    for (path, definition) in paths {
    532        let id = SourceId::for_path(&path)?;
    533        let mut source = RecursivePathSource::new(&path, id, ws.gctx());
    534        source.load().with_context(|| {
    535            format!(
    536                "failed to update path override `{}` \
    537                 (defined in `{}`)",
    538                path.display(),
    539                definition
    540            )
    541        })?;
    542        registry.add_override(Box::new(source));
    543    }
    544    Ok(())
    545}
    546
    547pub fn get_resolved_packages<'gctx>(
    548    resolve: &Resolve,
    549    registry: PackageRegistry<'gctx>,
    550) -> CargoResult<PackageSet<'gctx>> {
    551    let ids: Vec<PackageId> = resolve.iter().collect();
    552    registry.get(&ids)
    553}
    554
    555/// In this function we're responsible for informing the `registry` of all
    556/// locked dependencies from the previous lock file we had, `resolve`.
    557///
    558/// This gets particularly tricky for a couple of reasons. The first is that we
    559/// want all updates to be conservative, so we actually want to take the
    560/// `resolve` into account (and avoid unnecessary registry updates and such).
    561/// the second, however, is that we want to be resilient to updates of
    562/// manifests. For example if a dependency is added or a version is changed we
    563/// want to make sure that we properly re-resolve (conservatively) instead of
    564/// providing an opaque error.
    565///
    566/// The logic here is somewhat subtle, but there should be more comments below to
    567/// clarify things.
    568///
    569/// Note that this function, at the time of this writing, is basically the
    570/// entire fix for issue #4127.
    571#[tracing::instrument(skip_all)]
    572fn register_previous_locks(
    573    ws: &Workspace<'_>,
    574    registry: &mut PackageRegistry<'_>,
    575    resolve: &Resolve,
    576    keep: Keep<'_>,
    577    dev_deps: bool,
    578) {
    579    let path_pkg = |id: SourceId| {
    580        if !id.is_path() {
    581            return None;
    582        }
    583        if let Ok(path) = id.url().to_file_path() {
    584            if let Ok(pkg) = ws.load(&path.join("Cargo.toml")) {
    585                return Some(pkg);
    586            }
    587        }
    588        None
    589    };
    590
    591    // Ok so we've been passed in a `keep` function which basically says "if I
    592    // return `true` then this package wasn't listed for an update on the command
    593    // line". That is, if we run `cargo update foo` then `keep(bar)` will return
    594    // `true`, whereas `keep(foo)` will return `false` (roughly speaking).
    595    //
    596    // This isn't actually quite what we want, however. Instead we want to
    597    // further refine this `keep` function with *all transitive dependencies* of
    598    // the packages we're not keeping. For example, consider a case like this:
    599    //
    600    // * There's a crate `log`.
    601    // * There's a crate `serde` which depends on `log`.
    602    //
    603    // Let's say we then run `cargo update serde`. This may *also* want to
    604    // update the `log` dependency as our newer version of `serde` may have a
    605    // new minimum version required for `log`. Now this isn't always guaranteed
    606    // to work. What'll happen here is we *won't* lock the `log` dependency nor
    607    // the `log` crate itself, but we will inform the registry "please prefer
    608    // this version of `log`". That way if our newer version of serde works with
    609    // the older version of `log`, we conservatively won't update `log`. If,
    610    // however, nothing else in the dependency graph depends on `log` and the
    611    // newer version of `serde` requires a new version of `log` it'll get pulled
    612    // in (as we didn't accidentally lock it to an old version).
    613    let mut avoid_locking = HashSet::new();
    614    registry.add_to_yanked_whitelist(resolve.iter().filter(keep));
    615    for node in resolve.iter() {
    616        if !keep(&node) {
    617            add_deps(resolve, node, &mut avoid_locking);
    618        }
    619    }
    620
    621    // Ok, but the above loop isn't the entire story! Updates to the dependency
    622    // graph can come from two locations, the `cargo update` command or
    623    // manifests themselves. For example a manifest on the filesystem may
    624    // have been updated to have an updated version requirement on `serde`. In
    625    // this case both `keep(serde)` and `keep(log)` return `true` (the `keep`
    626    // that's an argument to this function). We, however, don't want to keep
    627    // either of those! Otherwise we'll get obscure resolve errors about locked
    628    // versions.
    629    //
    630    // To solve this problem we iterate over all packages with path sources
    631    // (aka ones with manifests that are changing) and take a look at all of
    632    // their dependencies. If any dependency does not match something in the
    633    // previous lock file, then we're guaranteed that the main resolver will
    634    // update the source of this dependency no matter what. Knowing this we
    635    // poison all packages from the same source, forcing them all to get
    636    // updated.
    637    //
    638    // This may seem like a heavy hammer, and it is! It means that if you change
    639    // anything from crates.io then all of crates.io becomes unlocked. Note,
    640    // however, that we still want conservative updates. This currently happens
    641    // because the first candidate the resolver picks is the previously locked
    642    // version, and only if that fails to activate to we move on and try
    643    // a different version. (giving the guise of conservative updates)
    644    //
    645    // For example let's say we had `serde = "0.1"` written in our lock file.
    646    // When we later edit this to `serde = "0.1.3"` we don't want to lock serde
    647    // at its old version, 0.1.1. Instead we want to allow it to update to
    648    // `0.1.3` and update its own dependencies (like above). To do this *all
    649    // crates from crates.io* are not locked (aka added to `avoid_locking`).
    650    // For dependencies like `log` their previous version in the lock file will
    651    // come up first before newer version, if newer version are available.
    652    {
    653        let _span = tracing::span!(tracing::Level::TRACE, "poison").entered();
    654        let mut path_deps = ws.members().cloned().collect::<Vec<_>>();
    655        let mut visited = HashSet::new();
    656        while let Some(member) = path_deps.pop() {
    657            if !visited.insert(member.package_id()) {
    658                continue;
    659            }
    660            let is_ws_member = ws.is_member(&member);
    661            for dep in member.dependencies() {
    662                // If this dependency didn't match anything special then we may want
    663                // to poison the source as it may have been added. If this path
    664                // dependencies is **not** a workspace member, however, and it's an
    665                // optional/non-transitive dependency then it won't be necessarily
    666                // be in our lock file. If this shows up then we avoid poisoning
    667                // this source as otherwise we'd repeatedly update the registry.
    668                //
    669                // TODO: this breaks adding an optional dependency in a
    670                // non-workspace member and then simultaneously editing the
    671                // dependency on that crate to enable the feature. For now,
    672                // this bug is better than the always-updating registry though.
    673                if !is_ws_member && (dep.is_optional() || !dep.is_transitive()) {
    674                    continue;
    675                }
    676
    677                // If dev-dependencies aren't being resolved, skip them.
    678                if !dep.is_transitive() && !dev_deps {
    679                    continue;
    680                }
    681
    682                // If this is a path dependency, then try to push it onto our
    683                // worklist.
    684                if let Some(pkg) = path_pkg(dep.source_id()) {
    685                    path_deps.push(pkg);
    686                    continue;
    687                }
    688
    689                // If we match *anything* in the dependency graph then we consider
    690                // ourselves all ok, and assume that we'll resolve to that.
    691                if resolve.iter().any(|id| dep.matches_ignoring_source(id)) {
    692                    continue;
    693                }
    694
    695                // Ok if nothing matches, then we poison the source of these
    696                // dependencies and the previous lock file.
    697                debug!(
    698                    "poisoning {} because {} looks like it changed {}",
    699                    dep.source_id(),
    700                    member.package_id(),
    701                    dep.package_name()
    702                );
    703                for id in resolve
    704                    .iter()
    705                    .filter(|id| id.source_id() == dep.source_id())
    706                {
    707                    add_deps(resolve, id, &mut avoid_locking);
    708                }
    709            }
    710        }
    711    }
    712
    713    // Additionally, here we process all path dependencies listed in the previous
    714    // resolve. They can not only have their dependencies change but also
    715    // the versions of the package change as well. If this ends up happening
    716    // then we want to make sure we don't lock a package ID node that doesn't
    717    // actually exist. Note that we don't do transitive visits of all the
    718    // package's dependencies here as that'll be covered below to poison those
    719    // if they changed.
    720    //
    721    // This must come after all other `add_deps` calls to ensure it recursively walks the tree when
    722    // called.
    723    for node in resolve.iter() {
    724        if let Some(pkg) = path_pkg(node.source_id()) {
    725            if pkg.package_id() != node {
    726                avoid_locking.insert(node);
    727            }
    728        }
    729    }
    730
    731    // Alright now that we've got our new, fresh, shiny, and refined `keep`
    732    // function let's put it to action. Take a look at the previous lock file,
    733    // filter everything by this callback, and then shove everything else into
    734    // the registry as a locked dependency.
    735    let keep = |id: &PackageId| keep(id) && !avoid_locking.contains(id);
    736
    737    registry.clear_lock();
    738    {
    739        let _span = tracing::span!(tracing::Level::TRACE, "register_lock").entered();
    740        for node in resolve.iter().filter(keep) {
    741            let deps = resolve
    742                .deps_not_replaced(node)
    743                .map(|p| p.0)
    744                .filter(keep)
    745                .collect::<Vec<_>>();
    746
    747            // In the v2 lockfile format and prior the `branch=master` dependency
    748            // directive was serialized the same way as the no-branch-listed
    749            // directive. Nowadays in Cargo, however, these two directives are
    750            // considered distinct and are no longer represented the same way. To
    751            // maintain compatibility with older lock files we register locked nodes
    752            // for *both* the master branch and the default branch.
    753            //
    754            // Note that this is only applicable for loading older resolves now at
    755            // this point. All new lock files are encoded as v3-or-later, so this is
    756            // just compat for loading an old lock file successfully.
    757            if let Some(node) = master_branch_git_source(node, resolve) {
    758                registry.register_lock(node, deps.clone());
    759            }
    760
    761            registry.register_lock(node, deps);
    762        }
    763    }
    764
    765    /// Recursively add `node` and all its transitive dependencies to `set`.
    766    fn add_deps(resolve: &Resolve, node: PackageId, set: &mut HashSet<PackageId>) {
    767        if !set.insert(node) {
    768            return;
    769        }
    770        debug!("ignoring any lock pointing directly at {}", node);
    771        for (dep, _) in resolve.deps_not_replaced(node) {
    772            add_deps(resolve, dep, set);
    773        }
    774    }
    775}
    776
    777fn master_branch_git_source(id: PackageId, resolve: &Resolve) -> Option<PackageId> {
    778    if resolve.version() <= ResolveVersion::V2 {
    779        let source = id.source_id();
    780        if let Some(GitReference::DefaultBranch) = source.git_reference() {
    781            let new_source =
    782                SourceId::for_git(source.url(), GitReference::Branch("master".to_string()))
    783                    .unwrap()
    784                    .with_precise_from(source);
    785            return Some(id.with_source_id(new_source));
    786        }
    787    }
    788    None
    789}
    790
    791/// Emits warnings of unused patches case by case.
    792///
    793/// This function does its best to provide more targeted and helpful
    794/// (such as showing close candidates that failed to match). However, that's
    795/// not terribly easy to do, so just show a general help message if we cannot.
    796fn emit_warnings_of_unused_patches(
    797    ws: &Workspace<'_>,
    798    resolve: &Resolve,
    799    registry: &PackageRegistry<'_>,
    800) -> CargoResult<()> {
    801    const MESSAGE: &str = "was not used in the crate graph.";
    802
    803    // Patch package with the source URLs being patch
    804    let mut patch_pkgid_to_urls = HashMap::new();
    805    for (url, summaries) in registry.patches().iter() {
    806        for summary in summaries.iter() {
    807            patch_pkgid_to_urls
    808                .entry(summary.package_id())
    809                .or_insert_with(HashSet::new)
    810                .insert(url);
    811        }
    812    }
    813
    814    // pkg name -> all source IDs of under the same pkg name
    815    let mut source_ids_grouped_by_pkg_name = HashMap::new();
    816    for pkgid in resolve.iter() {
    817        source_ids_grouped_by_pkg_name
    818            .entry(pkgid.name())
    819            .or_insert_with(HashSet::new)
    820            .insert(pkgid.source_id());
    821    }
    822
    823    let mut unemitted_unused_patches = Vec::new();
    824    for unused in resolve.unused_patches().iter() {
    825        // Show alternative source URLs if the source URLs being patch
    826        // cannot not be found in the crate graph.
    827        match (
    828            source_ids_grouped_by_pkg_name.get(&unused.name()),
    829            patch_pkgid_to_urls.get(unused),
    830        ) {
    831            (Some(ids), Some(patched_urls))
    832                if ids
    833                    .iter()
    834                    .all(|id| !patched_urls.contains(id.canonical_url())) =>
    835            {
    836                use std::fmt::Write;
    837                let mut msg = String::new();
    838                writeln!(msg, "Patch `{}` {}", unused, MESSAGE)?;
    839                write!(
    840                    msg,
    841                    "Perhaps you misspelled the source URL being patched.\n\
    842                    Possible URLs for `[patch.<URL>]`:",
    843                )?;
    844                for id in ids.iter() {
    845                    write!(msg, "\n    {}", id.display_registry_name())?;
    846                }
    847                ws.gctx().shell().warn(msg)?;
    848            }
    849            _ => unemitted_unused_patches.push(unused),
    850        }
    851    }
    852
    853    // Show general help message.
    854    if !unemitted_unused_patches.is_empty() {
    855        let warnings: Vec<_> = unemitted_unused_patches
    856            .iter()
    857            .map(|pkgid| format!("Patch `{}` {}", pkgid, MESSAGE))
    858            .collect();
    859        ws.gctx()
    860            .shell()
    861            .warn(format!("{}\n{}", warnings.join("\n"), UNUSED_PATCH_WARNING))?;
    862    }
    863
    864    return Ok(());
    865}
    866
    867/// Informs `registry` and `version_pref` that `[patch]` entries are available
    868/// and preferable for the dependency resolution.
    869///
    870/// This returns a set of PackageIds of `[patch]` entries, and some related
    871/// locked PackageIds, for which locking should be avoided (but which will be
    872/// preferred when searching dependencies, via [`VersionPreferences::prefer_patch_deps`]).
    873#[tracing::instrument(level = "debug", skip_all, ret)]
    874fn register_patch_entries(
    875    registry: &mut PackageRegistry<'_>,
    876    ws: &Workspace<'_>,
    877    previous: Option<&Resolve>,
    878    version_prefs: &mut VersionPreferences,
    879    keep_previous: Keep<'_>,
    880) -> CargoResult<HashSet<PackageId>> {
    881    let mut avoid_patch_ids = HashSet::new();
    882    for (url, patches) in ws.root_patch()?.iter() {
    883        for patch in patches {
    884            version_prefs.prefer_dependency(patch.clone());
    885        }
    886        let Some(previous) = previous else {
    887            let patches: Vec<_> = patches.iter().map(|p| (p, None)).collect();
    888            let unlock_ids = registry.patch(url, &patches)?;
    889            // Since nothing is locked, this shouldn't possibly return anything.
    890            assert!(unlock_ids.is_empty());
    891            continue;
    892        };
    893
    894        // This is a list of pairs where the first element of the pair is
    895        // the raw `Dependency` which matches what's listed in `Cargo.toml`.
    896        // The second element is, if present, the "locked" version of
    897        // the `Dependency` as well as the `PackageId` that it previously
    898        // resolved to. This second element is calculated by looking at the
    899        // previous resolve graph, which is primarily what's done here to
    900        // build the `registrations` list.
    901        let mut registrations = Vec::new();
    902        for dep in patches {
    903            let candidates = || {
    904                previous
    905                    .iter()
    906                    .chain(previous.unused_patches().iter().cloned())
    907                    .filter(&keep_previous)
    908            };
    909
    910            let lock = match candidates().find(|id| dep.matches_id(*id)) {
    911                // If we found an exactly matching candidate in our list of
    912                // candidates, then that's the one to use.
    913                Some(package_id) => {
    914                    let mut locked_dep = dep.clone();
    915                    locked_dep.lock_to(package_id);
    916                    Some(LockedPatchDependency {
    917                        dependency: locked_dep,
    918                        package_id,
    919                        alt_package_id: None,
    920                    })
    921                }
    922                None => {
    923                    // If the candidate does not have a matching source id
    924                    // then we may still have a lock candidate. If we're
    925                    // loading a v2-encoded resolve graph and `dep` is a
    926                    // git dep with `branch = 'master'`, then this should
    927                    // also match candidates without `branch = 'master'`
    928                    // (which is now treated separately in Cargo).
    929                    //
    930                    // In this scenario we try to convert candidates located
    931                    // in the resolve graph to explicitly having the
    932                    // `master` branch (if they otherwise point to
    933                    // `DefaultBranch`). If this works and our `dep`
    934                    // matches that then this is something we'll lock to.
    935                    match candidates().find(|&id| match master_branch_git_source(id, previous) {
    936                        Some(id) => dep.matches_id(id),
    937                        None => false,
    938                    }) {
    939                        Some(id_using_default) => {
    940                            let id_using_master = id_using_default.with_source_id(
    941                                dep.source_id()
    942                                    .with_precise_from(id_using_default.source_id()),
    943                            );
    944
    945                            let mut locked_dep = dep.clone();
    946                            locked_dep.lock_to(id_using_master);
    947                            Some(LockedPatchDependency {
    948                                dependency: locked_dep,
    949                                package_id: id_using_master,
    950                                // Note that this is where the magic
    951                                // happens, where the resolve graph
    952                                // probably has locks pointing to
    953                                // DefaultBranch sources, and by including
    954                                // this here those will get transparently
    955                                // rewritten to Branch("master") which we
    956                                // have a lock entry for.
    957                                alt_package_id: Some(id_using_default),
    958                            })
    959                        }
    960
    961                        // No locked candidate was found
    962                        None => None,
    963                    }
    964                }
    965            };
    966
    967            registrations.push((dep, lock));
    968        }
    969
    970        let canonical = CanonicalUrl::new(url)?;
    971        for (orig_patch, unlock_id) in registry.patch(url, &registrations)? {
    972            // Avoid the locked patch ID.
    973            avoid_patch_ids.insert(unlock_id);
    974            // Also avoid the thing it is patching.
    975            avoid_patch_ids.extend(previous.iter().filter(|id| {
    976                orig_patch.matches_ignoring_source(*id)
    977                    && *id.source_id().canonical_url() == canonical
    978            }));
    979        }
    980    }
    981
    982    Ok(avoid_patch_ids)
    983}
    984
    985/// Locks each `[replace]` entry to a specific Package ID
    986/// if the lockfile contains any corresponding previous replacement.
    987fn lock_replacements(
    988    ws: &Workspace<'_>,
    989    previous: Option<&Resolve>,
    990    keep: Keep<'_>,
    991) -> Vec<(PackageIdSpec, Dependency)> {
    992    let root_replace = ws.root_replace();
    993    let replace = match previous {
    994        Some(r) => root_replace
    995            .iter()
    996            .map(|(spec, dep)| {
    997                for (&key, &val) in r.replacements().iter() {
    998                    if spec.matches(key) && dep.matches_id(val) && keep(&val) {
    999                        let mut dep = dep.clone();
    1000                        dep.lock_to(val);
    1001                        return (spec.clone(), dep);
    1002                    }
    1003                }
    1004                (spec.clone(), dep.clone())
    1005            })
    1006            .collect::<Vec<_>>(),
    1007        None => root_replace.to_vec(),
    1008    };
    1009    replace
    1010}