Crate hir

HIR (previously known as descriptors) provides a high-level object-oriented access to Rust code.

The principal difference between HIR and syntax trees is that HIR is bound to a particular crate instance. That is, it has cfg flags and features applied. So, the relation between syntax and HIR is many-to-one.

HIR is the public API of the all of the compiler logic above syntax trees. It is written in “OO” style. Each type is self contained (as in, it knows its parents and full context). It should be “clean code”.

hir_* crates are the implementation of the compiler logic. They are written in “ECS” style, with relatively little abstractions. Many types are not self-contained, and explicitly use local indexes, arenas, etc.

hir is what insulates the “we don’t know how to actually write an incremental compiler” from the ide with completions, hovers, etc. It is a (soft, internal) boundary: https://www.tedinski.com/2018/02/06/system-boundaries.html.

Re-exports

• pub use crate::diagnostics::*;

Modules

• db
  Re-exports various subcrates databases so that the calling code can depend only on hir. This breaks abstraction boundary a bit, it would be cool if we didn’t do that.
• diagnostics
  Re-export diagnostics such that clients of hir don’t have to depend on low-level crates.
• import_map
  A map of all publicly exported items in a crate.
• mir
  MIR definitions and implementation
• sym
  Module defining all known symbols required by the rest of rust-analyzer.
• symbols
  File symbol extraction.
• term_search
  Term search
• tt

Structs

• Adjustment
• Attr
• AttrId
• AttrSourceMap
• AttributeTemplate
  A template that the attribute input must match. Only top-level shape (#[attr] vs #[attr(...)] vs #[attr = ...]) is considered now.
• Attrs
  Desugared attributes of an item post cfg_attr expansion.
• AttrsWithOwner
• BuiltinAttr
• BuiltinType
• Callable
• CaptureUsageSource
• CaptureUsages
• CfgOptions
  Configuration options used for conditional compilation on items with cfg attributes. We have two kind of options in different namespaces: atomic options like unix, and key-value options like target_arch="x86".
• ChalkTyInterner
• ChangeWithProcMacros
• Closure
• ClosureCapture
• Const
• ConstParam
• Crate
  hir::Crate describes a single crate. It’s the main interface with which a crate’s dependencies interact. Mostly, it should be just a proxy for the root module.
• CrateDependency
• DefMap
  Contains the results of (early) name resolution.
• DeriveHelper
• Enum
• EvaluatedConst
• ExternCrateDecl
• Field
• FilePositionWrapper
• FileRangeWrapper
• Function
• HirFileId
  Input to the analyzer is a set of files, where each file is identified by FileId and contains source code. However, another source of source code in Rust are macros: each macro can be thought of as producing a “temporary file”. To assign an id to such a file, we use the id of the macro call that produced the file. So, a HirFileId is either a FileId (source code written by user), or a MacroCallId (source code produced by macro).
• Impl
• ImportPathConfig
  A wrapper around three booleans
• InFileWrapper
  InFile<T> stores a value of T inside a particular file/syntax tree.
• InTypeConst
• InlineAsmOperand
• Label
• Layout
• LifetimeParam
• Local
  A single local definition.
• LocalSource
• Macro
• MacroFileId
• ModPath
• Module
• Name
  Name is a wrapper around string, which is used in hir for both references and declarations. In theory, names should also carry hygiene info, but we are not there yet!
• OverloadedDeref
• Param
• ProcMacros
• ProcMacrosBuilder
• SelfParam
• Semantics
  Primary API to get semantic information, like types, from syntax trees.
• SemanticsImpl
• SemanticsScope
  SemanticsScope encapsulates the notion of a scope (the set of visible names) at a particular program point.
• Static
• StaticLifetime
• Struct
• Symbol
• ToolModule
• Trait
• TraitAlias
• TraitRef
• TupleField
• Type
• TypeAlias
• TypeInfo
• TypeOrConstParam
• TypeParam
• Union
• Variant
• VisibleTraits

Enums

• Access
• Adjust
• Adt
  A Data Type
• AdtId
  A Data Type
• AssocItem
  Invariant: inner.as_assoc_item(db).is_some() We do not actively enforce this invariant.
• AssocItemContainer
• AutoBorrow
• BindingMode
• CallableKind
• CaptureKind
• CastError
• CfgAtom
  A simple configuration value passed in from the outside.
• CfgExpr
• ClosureStyle
• ConstEvalError
• DefWithBody
  The defs which have a body.
• DocLinkDef
  Subset of ide_db::Definition that doc links can resolve to.
• DynCompatibilityViolation
• ExternAssocItem
  Invariant: inner.as_extern_assoc_item(db).is_some() We do not actively enforce this invariant.
• FieldSource
• FnAbi
• GenericDef
• GenericParam
• HirDisplayError
• ItemContainer
• ItemInNs
• LangItem
  A representation of all the valid language items in Rust.
• LayoutError
• MacroId
  A macro
• MacroKind
• MethodViolationCode
• MirEvalError
• MirLowerError
• ModuleDef
  The defs which can be visible in the module.
• ModuleDefId
  The defs which can be visible in the module.
• ModuleSource
• Mutability
• Namespace
• PathKind
• PathResolution
• PointerCast
• PrefixKind
• Safety
  Whether a function is safe or not.
• ScopeDef
  For IDE only
• StructKind
• TyFingerprint
  This is used as a key for indexing impls.
• TypeRef
  Compare ty::Ty
• UnsafetyReason
• VariantDef
• Visibility
  Visibility of an item, with the path resolved.

Traits

• AsAssocItem
• AsExternAssocItem
• HasAttrs
• HasContainer
• HasCrate
  Trait for obtaining the defining crate of an item.
• HasSource
• HasVisibility
• HirDisplay
• HirFileIdExt
• HirWrite
• MacroFileIdExt
• SyntaxContextExt

Functions

• marks_rev
• prettify_macro_expansion
  Inserts whitespace and replaces $crate in macro expansions.
• resolve_doc_path_on
  Resolves the item link points to in the scope of def.

Type Aliases

• ExpandResult
• FilePosition
• FileRange
• HirFilePosition
• HirFileRange
• InFile
• InMacroFile
• InRealFile
• MacroFilePosition
• MacroFileRange