Struct cargo::core::compiler::Context

pub struct Context<'a, 'cfg> {
    pub bcx: &'a BuildContext<'a, 'cfg>,
    pub compilation: Compilation<'cfg>,
    pub build_script_outputs: Arc<Mutex<BuildScriptOutputs>>,
    pub build_explicit_deps: HashMap<Unit, BuildDeps>,
    pub fingerprints: HashMap<Unit, Arc<Fingerprint>>,
    pub mtime_cache: HashMap<PathBuf, FileTime>,
    pub compiled: HashSet<Unit>,
    pub build_scripts: HashMap<Unit, Arc<BuildScripts>>,
    pub jobserver: Client,
    pub lto: HashMap<Unit, Lto>,
    pub metadata_for_doc_units: HashMap<Unit, Metadata>,
    pub failed_scrape_units: Arc<Mutex<HashSet<Metadata>>>,
    /* private fields */
}

Collection of all the stuff that is needed to perform a build.

Different from the BuildContext, Context is a mutable state used throughout the entire build process. Everything is coordinated through this.

Fields

bcx: &'a BuildContext<'a, 'cfg>

Mostly static information about the build task.

compilation: Compilation<'cfg>

A large collection of information about the result of the entire compilation.

build_script_outputs: Arc<Mutex<BuildScriptOutputs>>

Output from build scripts, updated after each build script runs.

build_explicit_deps: HashMap<Unit, BuildDeps>

Dependencies (like rerun-if-changed) declared by a build script. This is only populated from the output from previous runs. If the build script hasn’t ever been run, then it must be run.

fingerprints: HashMap<Unit, Arc<Fingerprint>>

Fingerprints used to detect if a unit is out-of-date.

mtime_cache: HashMap<PathBuf, FileTime>

Cache of file mtimes to reduce filesystem hits.

compiled: HashSet<Unit>

A set used to track which units have been compiled. A unit may appear in the job graph multiple times as a dependency of multiple packages, but it only needs to run once.

build_scripts: HashMap<Unit, Arc<BuildScripts>>

Linking information for each Unit. See build_map for details.

jobserver: Client

Job server client to manage concurrency with other processes.

lto: HashMap<Unit, Lto>

Map of the LTO-status of each unit. This indicates what sort of compilation is happening (only object, only bitcode, both, etc), and is precalculated early on.

metadata_for_doc_units: HashMap<Unit, Metadata>

Map of Doc/Docscrape units to metadata for their -Cmetadata flag. See Context::find_metadata_units for more details.

failed_scrape_units: Arc<Mutex<HashSet<Metadata>>>

Set of metadata of Docscrape units that fail before completion, e.g. because the target has a type error. This is in an Arc<Mutex<..>> because it is continuously updated as the job progresses.

Implementations

impl<'a, 'cfg> Context<'a, 'cfg>

pub fn new(bcx: &'a BuildContext<'a, 'cfg>) -> CargoResult<Self>

pub fn compile(self, exec: &Arc<dyn Executor>) -> CargoResult<Compilation<'cfg>>

Starts compilation, waits for it to finish, and returns information about the result of compilation.

See ops::cargo_compile for a higher-level view of the compile process.

pub fn get_executable(&mut self, unit: &Unit) -> CargoResult<Option<PathBuf>>

Returns the executable for the specified unit (if any).

pub fn prepare_units(&mut self) -> CargoResult<()>

pub fn prepare(&mut self) -> CargoResult<()>

Prepare this context, ensuring that all filesystem directories are in place.

pub fn files(&self) -> &CompilationFiles<'a, 'cfg>

pub fn outputs(&self, unit: &Unit) -> CargoResult<Arc<Vec<OutputFile>>>

Returns the filenames that the given unit will generate.

pub fn unit_deps(&self, unit: &Unit) -> &[UnitDep]

Direct dependencies for the given unit.

pub fn find_build_script_unit(&self, unit: &Unit) -> Option<Unit>

Returns the RunCustomBuild Unit associated with the given Unit.

If the package does not have a build script, this returns None.

pub fn find_build_script_metadata(&self, unit: &Unit) -> Option<Metadata>

Returns the metadata hash for the RunCustomBuild Unit associated with the given unit.

If the package does not have a build script, this returns None.

pub fn get_run_build_script_metadata(&self, unit: &Unit) -> Metadata

Returns the metadata hash for a RunCustomBuild unit.

pub fn is_primary_package(&self, unit: &Unit) -> bool

pub fn build_plan_inputs(&self) -> CargoResult<Vec<PathBuf>>

Returns the list of filenames read by cargo to generate the BuildContext (all Cargo.toml, etc.).

pub fn unit_output(&self, unit: &Unit, path: &Path) -> UnitOutput

Returns a UnitOutput which represents some information about the output of a unit.

pub fn only_requires_rmeta(&self, parent: &Unit, dep: &Unit) -> bool

Returns whether when parent depends on dep if it only requires the metadata file from dep.

pub fn rmeta_required(&self, unit: &Unit) -> bool

Returns whether when unit is built whether it should emit metadata as well because some compilations rely on that.

pub fn compute_metadata_for_doc_units(&mut self)

Finds metadata for Doc/Docscrape units.

rustdoc needs a -Cmetadata flag in order to recognize StableCrateIds that refer to items in the crate being documented. The -Cmetadata flag used by reverse-dependencies will be the metadata of the Cargo unit that generated the current library’s rmeta file, which should be a Check unit.

If the current crate has reverse-dependencies, such a Check unit should exist, and so we use that crate’s metadata. If not, we use the crate’s Doc unit so at least examples scraped from the current crate can be used when documenting the current crate.