Appendix D: Code Index

rustc has a lot of important data structures. This is an attempt to give some guidance on where to learn more about some of the key data structures of the compiler.

Item	Kind	Short description	Chapter	Declaration
BodyId	struct	One of four types of HIR node identifiers	Identifiers in the HIR	src/librustc/hir/mod.rs
Compiler	struct	Represents a compiler session and can be used to drive a compilation.	The Rustc Driver and Interface	src/librustc_interface/interface.rs
ast::Crate	struct	A syntax-level representation of a parsed crate	The parser	src/librustc/hir/mod.rs
hir::Crate	struct	A more abstract, compiler-friendly form of a crate's AST	The Hir	src/librustc/hir/mod.rs
DefId	struct	One of four types of HIR node identifiers	Identifiers in the HIR	src/librustc/hir/def_id.rs
DiagnosticBuilder	struct	A struct for building up compiler diagnostics, such as errors or lints	Emitting Diagnostics	src/librustc_errors/diagnostic_builder.rs
DocContext	struct	A state container used by rustdoc when crawling through a crate to gather its documentation	Rustdoc	src/librustdoc/core.rs
HirId	struct	One of four types of HIR node identifiers	Identifiers in the HIR	src/librustc/hir/mod.rs
NodeId	struct	One of four types of HIR node identifiers. Being phased out	Identifiers in the HIR	src/libsyntax/ast.rs
P	struct	An owned immutable smart pointer. By contrast, &T is not owned, and Box<T> is not immutable.	None	src/syntax/ptr.rs
ParamEnv	struct	Information about generic parameters or Self, useful for working with associated or generic items	Parameter Environment	src/librustc/ty/mod.rs
ParseSess	struct	This struct contains information about a parsing session	The parser	src/libsyntax/parse/mod.rs
Query	struct	Represents the result of query to the Compiler interface and allows stealing, borrowing, and returning the results of compiler passes.	The Rustc Driver and Interface	src/librustc_interface/queries.rs
Rib	struct	Represents a single scope of names	Name resolution	src/librustc_resolve/lib.rs
Session	struct	The data associated with a compilation session	The parser, The Rustc Driver and Interface	src/librustc/session/mod.html
SourceFile	struct	Part of the SourceMap. Maps AST nodes to their source code for a single source file. Was previously called FileMap	The parser	src/libsyntax_pos/lib.rs
SourceMap	struct	Maps AST nodes to their source code. It is composed of SourceFiles. Was previously called CodeMap	The parser	src/libsyntax/source_map.rs
Span	struct	A location in the user's source code, used for error reporting primarily	Emitting Diagnostics	src/libsyntax_pos/span_encoding.rs
StringReader	struct	This is the lexer used during parsing. It consumes characters from the raw source code being compiled and produces a series of tokens for use by the rest of the parser	The parser	src/libsyntax/parse/lexer/mod.rs
syntax::token_stream::TokenStream	struct	An abstract sequence of tokens, organized into TokenTrees	The parser, Macro expansion	src/libsyntax/tokenstream.rs
TraitDef	struct	This struct contains a trait's definition with type information	The ty modules	src/librustc/ty/trait_def.rs
TraitRef	struct	The combination of a trait and its input types (e.g. P0: Trait<P1...Pn>)	Trait Solving: Goals and Clauses, Trait Solving: Lowering impls	src/librustc/ty/sty.rs
Ty<'tcx>	struct	This is the internal representation of a type used for type checking	Type checking	src/librustc/ty/mod.rs
TyCtxt<'tcx>	struct	The “typing context”. This is the central data structure in the compiler. It is the context that you use to perform all manner of queries	The ty modules	src/librustc/ty/context.rs