Crate rustc_span

Source positions and related helper functions.

Important concepts in this module include:

• the span, represented by SpanData and related types;
• source code as represented by a SourceMap; and
• interned strings, represented by Symbols, with some common symbols available statically in the sym module.

Unlike most compilers, the span contains not only the position in the source code, but also various other metadata, such as the edition and macro hygiene. This metadata is stored in SyntaxContext and ExpnData.

Note

This API is completely unstable and subject to change.

Re-exports

• pub use hygiene::DesugaringKind;
• pub use hygiene::ExpnData;
• pub use hygiene::ExpnHash;
• pub use hygiene::ExpnId;
• pub use hygiene::ExpnKind;
• pub use hygiene::LocalExpnId;
• pub use hygiene::MacroKind;
• pub use hygiene::SyntaxContext;
• pub use symbol::Symbol;
• pub use symbol::sym;

Modules

• analyze_source_file 🔒
• caching_source_map_view 🔒
• def_id
• edit_distance
  Edit distances.
• edition
• fatal_error
• hygiene
  Machinery for hygienic macros.
• profiling
• source_map
  Types for tracking pieces of source code within a crate.
• span_encoding 🔒
• symbol
  An “interner” is a data structure that associates values with usize tags and allows bidirectional lookup; i.e., given a value, one can easily find the type, and vice versa.

Macros

• impl_pos 🔒

Structs

• AttrId
• BytePos
  A byte offset.
• CachingSourceMapView
• CharPos
  A character offset.
• DistinctSources
• ErrorGuaranteed
  Useful type to use with Result<> indicate that an error has already been reported to the user, so no need to continue checking.
• FileLines
• FileNameDisplay
• InnerSpan
  Range inside of a Span used for diagnostics when we only have access to relative positions.
• LineInfo
• Loc
  A source code location used for error reporting.
• MalformedSourceMapPositions
• MultiByteChar
  Identifies an offset of a multi-byte character in a SourceFile.
• NormalizedPos
  Identifies an offset of a character that was normalized away from SourceFile.
• OffsetOverflowError
• RelativeBytePos
  A byte offset relative to file beginning.
• SessionGlobals
  Per-session global variables: this struct is stored in thread-local storage in such a way that it is accessible without any kind of handle to all threads within the compilation session, but is not accessible outside the session.
• SourceFile
  A single source in the SourceMap.
• SourceFileAndBytePos
• SourceFileAndLine
• SourceFileDiffs
  The source file lines in difference list form. This matches the form used within metadata, which saves space by exploiting the fact that the lines list is sorted and individual lines are usually not that long.
• SourceFileHash
  The hash of the on-disk source file used for debug info and cargo freshness checks.
• Span
  A compressed span.
• SpanData
  Represents a span.
• StableSourceFileId
  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).

Enums

• ExternalSource
• ExternalSourceKind
  The state of the lazy external source loading mechanism of a SourceFile.
• FileName
  Differentiates between real files and common virtual files.
• FileNameDisplayPreference
• RealFileName
• SourceFileHashAlgorithm
• SourceFileLines
• SpanLinesError
• SpanSnippetError

Constants

• DUMMY_SP
  The dummy span has zero position, length, and context, and no parent.

Statics

• SESSION_GLOBALS 🔒
• SPAN_TRACK

Traits

• HashStableContext
  Requirements for a StableHashingContext to be used in this crate.
• Pos
• SpanDecoder
  This trait is used to allow decoder specific encodings of certain types. It is similar to rustc_type_ir’s TyDecoder.
• SpanEncoder
  This trait is used to allow encoder specific encodings of certain types. It is similar to rustc_type_ir’s TyEncoder.

Functions

• char_width
• create_default_session_globals_then
  Default edition, no source map.
• create_session_globals_then
• create_session_if_not_set_then
  No source map.
• normalize_newlines 🔒
  Replaces \r\n with \n in-place in src.
• normalize_src 🔒
  Normalizes the source code and records the normalizations.
• remove_bom 🔒
  Removes UTF-8 BOM, if any.
• set_session_globals_then
• str_width
• with_metavar_spans
• with_session_globals

Type Aliases

• FileLinesResult