//! FIXME: write short doc here
pub(crate) mod lower;
pub(crate) mod scope;
pub(crate) mod validation;
use std::{ops::Index, sync::Arc};
use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
use ra_syntax::{ast, AstPtr};
use rustc_hash::FxHashMap;
use crate::{
db::HirDatabase,
path::GenericArgs,
ty::primitive::{UncertainFloatTy, UncertainIntTy},
type_ref::{Mutability, TypeRef},
DefWithBody, Either, HasSource, Name, Path, Resolver, Source,
};
pub use self::scope::ExprScopes;
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct ExprId(RawId);
impl_arena_id!(ExprId);
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct PatId(RawId);
impl_arena_id!(PatId);
/// The body of an item (function, const etc.).
#[derive(Debug, Eq, PartialEq)]
pub struct Body {
/// The def of the item this body belongs to
owner: DefWithBody,
exprs: Arena<ExprId, Expr>,
pats: Arena<PatId, Pat>,
/// The patterns for the function's parameters. While the parameter types are
/// part of the function signature, the patterns are not (they don't change
/// the external type of the function).
///
/// If this `Body` is for the body of a constant, this will just be
/// empty.
params: Vec<PatId>,
/// The `ExprId` of the actual body expression.
body_expr: ExprId,
}
type ExprPtr = Either<AstPtr<ast::Expr>, AstPtr<ast::RecordField>>;
type ExprSource = Source<ExprPtr>;
type PatPtr = Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>;
type PatSource = Source<PatPtr>;
/// An item body together with the mapping from syntax nodes to HIR expression
/// IDs. This is needed to go from e.g. a position in a file to the HIR
/// expression containing it; but for type inference etc., we want to operate on
/// a structure that is agnostic to the actual positions of expressions in the
/// file, so that we don't recompute types whenever some whitespace is typed.
///
/// One complication here is that, due to macro expansion, a single `Body` might
/// be spread across several files. So, for each ExprId and PatId, we record
/// both the HirFileId and the position inside the file. However, we only store
/// AST -> ExprId mapping for non-macro files, as it is not clear how to handle
/// this properly for macros.
#[derive(Default, Debug, Eq, PartialEq)]
pub struct BodySourceMap {
expr_map: FxHashMap<ExprPtr, ExprId>,
expr_map_back: ArenaMap<ExprId, ExprSource>,
pat_map: FxHashMap<PatPtr, PatId>,
pat_map_back: ArenaMap<PatId, PatSource>,
field_map: FxHashMap<(ExprId, usize), AstPtr<ast::RecordField>>,
}
impl Body {
pub fn params(&self) -> &[PatId] {
&self.params
}
pub fn body_expr(&self) -> ExprId {
self.body_expr
}
pub fn owner(&self) -> DefWithBody {
self.owner
}
pub fn exprs(&self) -> impl Iterator<Item = (ExprId, &Expr)> {
self.exprs.iter()
}
pub fn pats(&self) -> impl Iterator<Item = (PatId, &Pat)> {
self.pats.iter()
}
}
// needs arbitrary_self_types to be a method... or maybe move to the def?
pub(crate) fn resolver_for_expr(
body: Arc<Body>,
db: &impl HirDatabase,
expr_id: ExprId,
) -> Resolver {
let scopes = db.expr_scopes(body.owner);
resolver_for_scope(body, db, scopes.scope_for(expr_id))
}
pub(crate) fn resolver_for_scope(
body: Arc<Body>,
db: &impl HirDatabase,
scope_id: Option<scope::ScopeId>,
) -> Resolver {
let mut r = body.owner.resolver(db);
let scopes = db.expr_scopes(body.owner);
let scope_chain = scopes.scope_chain(scope_id).collect::<Vec<_>>();
for scope in scope_chain.into_iter().rev() {
r = r.push_expr_scope(Arc::clone(&scopes), scope);
}
r
}
impl Index<ExprId> for Body {
type Output = Expr;
fn index(&self, expr: ExprId) -> &Expr {
&self.exprs[expr]
}
}
impl Index<PatId> for Body {
type Output = Pat;
fn index(&self, pat: PatId) -> &Pat {
&self.pats[pat]
}
}
impl BodySourceMap {
pub(crate) fn expr_syntax(&self, expr: ExprId) -> Option<ExprSource> {
self.expr_map_back.get(expr).copied()
}
pub(crate) fn node_expr(&self, node: &ast::Expr) -> Option<ExprId> {
self.expr_map.get(&Either::A(AstPtr::new(node))).cloned()
}
pub(crate) fn pat_syntax(&self, pat: PatId) -> Option<PatSource> {
self.pat_map_back.get(pat).copied()
}
pub(crate) fn node_pat(&self, node: &ast::Pat) -> Option<PatId> {
self.pat_map.get(&Either::A(AstPtr::new(node))).cloned()
}
pub(crate) fn field_syntax(&self, expr: ExprId, field: usize) -> AstPtr<ast::RecordField> {
self.field_map[&(expr, field)]
}
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Literal {
String(String),
ByteString(Vec<u8>),
Char(char),
Bool(bool),
Int(u64, UncertainIntTy),
Float(u64, UncertainFloatTy), // FIXME: f64 is not Eq
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Expr {
/// This is produced if syntax tree does not have a required expression piece.
Missing,
Path(Path),
If {
condition: ExprId,
then_branch: ExprId,
else_branch: Option<ExprId>,
},
Block {
statements: Vec<Statement>,
tail: Option<ExprId>,
},
Loop {
body: ExprId,
},
While {
condition: ExprId,
body: ExprId,
},
For {
iterable: ExprId,
pat: PatId,
body: ExprId,
},
Call {
callee: ExprId,
args: Vec<ExprId>,
},
MethodCall {
receiver: ExprId,
method_name: Name,
args: Vec<ExprId>,
generic_args: Option<GenericArgs>,
},
Match {
expr: ExprId,
arms: Vec<MatchArm>,
},
Continue,
Break {
expr: Option<ExprId>,
},
Return {
expr: Option<ExprId>,
},
RecordLit {
path: Option<Path>,
fields: Vec<RecordLitField>,
spread: Option<ExprId>,
},
Field {
expr: ExprId,
name: Name,
},
Await {
expr: ExprId,
},
Try {
expr: ExprId,
},
TryBlock {
body: ExprId,
},
Cast {
expr: ExprId,
type_ref: TypeRef,
},
Ref {
expr: ExprId,
mutability: Mutability,
},
Box {
expr: ExprId,
},
UnaryOp {
expr: ExprId,
op: UnaryOp,
},
BinaryOp {
lhs: ExprId,
rhs: ExprId,
op: Option<BinaryOp>,
},
Index {
base: ExprId,
index: ExprId,
},
Lambda {
args: Vec<PatId>,
arg_types: Vec<Option<TypeRef>>,
body: ExprId,
},
Tuple {
exprs: Vec<ExprId>,
},
Array(Array),
Literal(Literal),
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
pub enum BinaryOp {
LogicOp(LogicOp),
ArithOp(ArithOp),
CmpOp(CmpOp),
Assignment { op: Option<ArithOp> },
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
pub enum LogicOp {
And,
Or,
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
pub enum CmpOp {
Eq { negated: bool },
Ord { ordering: Ordering, strict: bool },
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
pub enum Ordering {
Less,
Greater,
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
pub enum ArithOp {
Add,
Mul,
Sub,
Div,
Rem,
Shl,
Shr,
BitXor,
BitOr,
BitAnd,
}
pub use ra_syntax::ast::PrefixOp as UnaryOp;
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Array {
ElementList(Vec<ExprId>),
Repeat { initializer: ExprId, repeat: ExprId },
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct MatchArm {
pub pats: Vec<PatId>,
pub guard: Option<ExprId>,
pub expr: ExprId,
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct RecordLitField {
pub name: Name,
pub expr: ExprId,
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Statement {
Let { pat: PatId, type_ref: Option<TypeRef>, initializer: Option<ExprId> },
Expr(ExprId),
}
impl Expr {
pub fn walk_child_exprs(&self, mut f: impl FnMut(ExprId)) {
match self {
Expr::Missing => {}
Expr::Path(_) => {}
Expr::If { condition, then_branch, else_branch } => {
f(*condition);
f(*then_branch);
if let Some(else_branch) = else_branch {
f(*else_branch);
}
}
Expr::Block { statements, tail } => {
for stmt in statements {
match stmt {
Statement::Let { initializer, .. } => {
if let Some(expr) = initializer {
f(*expr);
}
}
Statement::Expr(e) => f(*e),
}
}
if let Some(expr) = tail {
f(*expr);
}
}
Expr::TryBlock { body } => f(*body),
Expr::Loop { body } => f(*body),
Expr::While { condition, body } => {
f(*condition);
f(*body);
}
Expr::For { iterable, body, .. } => {
f(*iterable);
f(*body);
}
Expr::Call { callee, args } => {
f(*callee);
for arg in args {
f(*arg);
}
}
Expr::MethodCall { receiver, args, .. } => {
f(*receiver);
for arg in args {
f(*arg);
}
}
Expr::Match { expr, arms } => {
f(*expr);
for arm in arms {
f(arm.expr);
}
}
Expr::Continue => {}
Expr::Break { expr } | Expr::Return { expr } => {
if let Some(expr) = expr {
f(*expr);
}
}
Expr::RecordLit { fields, spread, .. } => {
for field in fields {
f(field.expr);
}
if let Some(expr) = spread {
f(*expr);
}
}
Expr::Lambda { body, .. } => {
f(*body);
}
Expr::BinaryOp { lhs, rhs, .. } => {
f(*lhs);
f(*rhs);
}
Expr::Index { base, index } => {
f(*base);
f(*index);
}
Expr::Field { expr, .. }
| Expr::Await { expr }
| Expr::Try { expr }
| Expr::Cast { expr, .. }
| Expr::Ref { expr, .. }
| Expr::UnaryOp { expr, .. }
| Expr::Box { expr } => {
f(*expr);
}
Expr::Tuple { exprs } => {
for expr in exprs {
f(*expr);
}
}
Expr::Array(a) => match a {
Array::ElementList(exprs) => {
for expr in exprs {
f(*expr);
}
}
Array::Repeat { initializer, repeat } => {
f(*initializer);
f(*repeat)
}
},
Expr::Literal(_) => {}
}
}
}
/// Explicit binding annotations given in the HIR for a binding. Note
/// that this is not the final binding *mode* that we infer after type
/// inference.
#[derive(Clone, PartialEq, Eq, Debug, Copy)]
pub enum BindingAnnotation {
/// No binding annotation given: this means that the final binding mode
/// will depend on whether we have skipped through a `&` reference
/// when matching. For example, the `x` in `Some(x)` will have binding
/// mode `None`; if you do `let Some(x) = &Some(22)`, it will
/// ultimately be inferred to be by-reference.
Unannotated,
/// Annotated with `mut x` -- could be either ref or not, similar to `None`.
Mutable,
/// Annotated as `ref`, like `ref x`
Ref,
/// Annotated as `ref mut x`.
RefMut,
}
impl BindingAnnotation {
fn new(is_mutable: bool, is_ref: bool) -> Self {
match (is_mutable, is_ref) {
(true, true) => BindingAnnotation::RefMut,
(false, true) => BindingAnnotation::Ref,
(true, false) => BindingAnnotation::Mutable,
(false, false) => BindingAnnotation::Unannotated,
}
}
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct RecordFieldPat {
pub(crate) name: Name,
pub(crate) pat: PatId,
}
/// Close relative to rustc's hir::PatKind
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Pat {
Missing,
Wild,
Tuple(Vec<PatId>),
Record {
path: Option<Path>,
args: Vec<RecordFieldPat>,
// FIXME: 'ellipsis' option
},
Range {
start: ExprId,
end: ExprId,
},
Slice {
prefix: Vec<PatId>,
rest: Option<PatId>,
suffix: Vec<PatId>,
},
Path(Path),
Lit(ExprId),
Bind {
mode: BindingAnnotation,
name: Name,
subpat: Option<PatId>,
},
TupleStruct {
path: Option<Path>,
args: Vec<PatId>,
},
Ref {
pat: PatId,
mutability: Mutability,
},
}
impl Pat {
pub fn walk_child_pats(&self, mut f: impl FnMut(PatId)) {
match self {
Pat::Range { .. } | Pat::Lit(..) | Pat::Path(..) | Pat::Wild | Pat::Missing => {}
Pat::Bind { subpat, .. } => {
subpat.iter().copied().for_each(f);
}
Pat::Tuple(args) | Pat::TupleStruct { args, .. } => {
args.iter().copied().for_each(f);
}
Pat::Ref { pat, .. } => f(*pat),
Pat::Slice { prefix, rest, suffix } => {
let total_iter = prefix.iter().chain(rest.iter()).chain(suffix.iter());
total_iter.copied().for_each(f);
}
Pat::Record { args, .. } => {
args.iter().map(|f| f.pat).for_each(f);
}
}
}
}
// Queries
pub(crate) fn body_with_source_map_query(
db: &impl HirDatabase,
def: DefWithBody,
) -> (Arc<Body>, Arc<BodySourceMap>) {
let mut params = None;
let (file_id, body) = match def {
DefWithBody::Function(f) => {
let src = f.source(db);
params = src.ast.param_list();
(src.file_id, src.ast.body().map(ast::Expr::from))
}
DefWithBody::Const(c) => {
let src = c.source(db);
(src.file_id, src.ast.body())
}
DefWithBody::Static(s) => {
let src = s.source(db);
(src.file_id, src.ast.body())
}
};
let (body, source_map) = lower::lower(db, def.resolver(db), file_id, def, params, body);
(Arc::new(body), Arc::new(source_map))
}
pub(crate) fn body_hir_query(db: &impl HirDatabase, def: DefWithBody) -> Arc<Body> {
db.body_with_source_map(def).0
}