Struct rustc_span::source_map::StableSourceFileId

pub struct StableSourceFileId {
    pub file_name_hash: u64,
    pub cnum: CrateNum,
}

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).

The StableSourceFileId also contains the CrateNum of the crate the source file was originally parsed for. This way we get two separate entries in the SourceMap if the same file is part of both the local and an upstream crate. Trying to only have one entry for both cases is problematic because at the point where we discover that there’s a local use of the file in addition to the upstream one, we might already have made decisions based on the assumption that it’s an upstream file. Treating the two files as different has no real downsides.

Fields

file_name_hash: u64

A hash of the source file’s FileName. This is hash so that it’s size is more predictable than if we included the actual FileName value.

cnum: CrateNum

The CrateNum of the crate this source file was originally parsed for. We cannot include this information in the hash because at the time of hashing we don’t have the context to map from the CrateNum’s numeric value to a StableCrateId.

Implementations

impl StableSourceFileId

pub fn new(source_file: &SourceFile) -> StableSourceFileId

fn new_from_name(name: &FileName, cnum: CrateNum) -> StableSourceFileId

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: Decoder> Decodable<__D> for StableSourceFileId

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

impl<__E: Encoder> 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 PartialEq<StableSourceFileId> 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 Copy for StableSourceFileId

impl Eq for StableSourceFileId

impl StructuralEq 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