Struct StableHashingContext 

pub struct StableHashingContext<'a> {
    untracked: &'a Untracked,
    incremental_ignore_spans: bool,
    caching_source_map: CachingSourceMap<'a>,
    hashing_controls: HashingControls,
}

This is the context state available during incr. comp. hashing. It contains enough information to transform DefIds and HirIds into stable DefPaths (i.e., a reference to the TyCtxt) and it holds a few caches for speeding up various things (e.g., each DefId/DefPath is only hashed once).

Fields

untracked: &'a Untracked

incremental_ignore_spans: bool

caching_source_map: CachingSourceMap<'a>

hashing_controls: HashingControls

Implementations

impl<'a> StableHashingContext<'a>

pub fn new(sess: &'a Session, untracked: &'a Untracked) -> Self

pub fn while_hashing_spans<F: FnOnce(&mut Self)>( &mut self, hash_spans: bool, f: F, )

fn source_map(&mut self) -> &mut CachingSourceMapView<'a>

fn def_span(&self, def_id: LocalDefId) -> Span

pub fn hashing_controls(&self) -> HashingControls

Trait Implementations

impl<'a> HashStableContext for StableHashingContext<'a>

fn span_hash_stable(&mut self, raw_span: RawSpan, hasher: &mut StableHasher)

Hashes a span in a stable way. We can’t directly hash the span’s BytePos fields (that would be similar to hashing pointers, since those are just offsets into the SourceMap). Instead, we hash the (file name, line, column) triple, which stays the same even if the containing SourceFile has moved within the SourceMap.

Also note that we are hashing byte offsets for the column, not unicode codepoint offsets. For the purpose of the hash that’s sufficient. Also, hashing filenames is expensive so we avoid doing it twice when the span starts and ends in the same file, which is almost always the case.

IMPORTANT: changes to this method should be reflected in implementations of SpanEncoder.

fn assert_default_hashing_controls(&self, msg: &str)

Assert that the provided HashStableContext is configured with the default HashingControls. We should always have bailed out before getting to here with a non-default mode. With this check in place, we can avoid the need to maintain separate versions of ExpnData hashes for each permutation of HashingControls settings.

fn def_path_hash(&self, raw_def_id: RawDefId) -> RawDefPathHash

Compute a DefPathHash.

fn hashing_controls(&self) -> HashingControls

Get the hashing controls.

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: 48 bytes