Struct rustc_span::StableSourceFileId

pub struct StableSourceFileId(pub(crate) Hash128);

This is a SourceFile identifier that is used to correlate source files between subsequent compilation sessions (which is something we need to do during incremental compilation).

It is a hash value (so we can efficiently consume it when stable-hashing spans) that consists of the FileName and the StableCrateId of the crate the source file is from. The crate id is needed because sometimes the FileName is not unique within the crate graph (think src/lib.rs, for example).

The way the crate-id part is handled is a bit special: source files of the local crate are hashed as (filename, None), while source files from upstream crates have a hash of (filename, Some(stable_crate_id)). This is because SourceFiles for the local crate are allocated very early in the compilation process when the StableCrateId is not yet known. If, due to some refactoring of the compiler, the StableCrateId of the local crate were to become available, it would be better to uniformely make this a hash of (filename, stable_crate_id).

When SourceFiles are exported in crate metadata, the StableSourceFileId is updated to incorporate the StableCrateId of the exporting crate.

Tuple Fields

0: Hash128

Implementations

impl StableSourceFileId

pub(crate) fn from_filename_in_current_crate(filename: &FileName) -> Self

pub fn from_filename_for_export( filename: &FileName, local_crate_stable_crate_id: StableCrateId ) -> Self

pub(crate) fn from_filename_and_stable_crate_id( filename: &FileName, stable_crate_id: Option<StableCrateId> ) -> Self

Trait Implementations

impl Clone for StableSourceFileId

fn clone(&self) -> StableSourceFileId

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StableSourceFileId

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<__D: SpanDecoder> Decodable<__D> for StableSourceFileId

fn decode(__decoder: &mut __D) -> Self

impl Default for StableSourceFileId

fn default() -> StableSourceFileId

Returns the “default value” for a type.

impl<__E: SpanEncoder> Encodable<__E> for StableSourceFileId

fn encode(&self, __encoder: &mut __E)

impl Hash for StableSourceFileId

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<__CTX> HashStable<__CTX> for StableSourceFileId

where __CTX: HashStableContext,

fn hash_stable(&self, __hcx: &mut __CTX, __hasher: &mut StableHasher)

impl Ord for StableSourceFileId

fn cmp(&self, other: &StableSourceFileId) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for StableSourceFileId

fn eq(&self, other: &StableSourceFileId) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for StableSourceFileId

fn partial_cmp(&self, other: &StableSourceFileId) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for StableSourceFileId

impl Eq for StableSourceFileId

impl StructuralPartialEq for StableSourceFileId

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes