rust/crates/hir-def/src/hir.rs
2023-07-18 18:52:34 +08:00

559 lines
16 KiB
Rust

//! This module describes hir-level representation of expressions.
//!
//! This representation is:
//!
//! 1. Identity-based. Each expression has an `id`, so we can distinguish
//! between different `1` in `1 + 1`.
//! 2. Independent of syntax. Though syntactic provenance information can be
//! attached separately via id-based side map.
//! 3. Unresolved. Paths are stored as sequences of names, and not as defs the
//! names refer to.
//! 4. Desugared. There's no `if let`.
//!
//! See also a neighboring `body` module.
pub mod type_ref;
use std::fmt;
use hir_expand::name::Name;
use intern::Interned;
use la_arena::{Idx, RawIdx};
use smallvec::SmallVec;
use syntax::ast;
use crate::{
builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
path::{GenericArgs, Path},
type_ref::{Mutability, Rawness, TypeRef},
BlockId, ConstBlockId,
};
pub use syntax::ast::{ArithOp, BinaryOp, CmpOp, LogicOp, Ordering, RangeOp, UnaryOp};
pub type BindingId = Idx<Binding>;
pub type ExprId = Idx<Expr>;
/// FIXME: this is a hacky function which should be removed
pub(crate) fn dummy_expr_id() -> ExprId {
ExprId::from_raw(RawIdx::from(u32::MAX))
}
pub type PatId = Idx<Pat>;
#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
pub enum ExprOrPatId {
ExprId(ExprId),
PatId(PatId),
}
stdx::impl_from!(ExprId, PatId for ExprOrPatId);
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Label {
pub name: Name,
}
pub type LabelId = Idx<Label>;
// We convert float values into bits and that's how we don't need to deal with f32 and f64.
// For PartialEq, bits comparison should work, as ordering is not important
// https://github.com/rust-lang/rust-analyzer/issues/12380#issuecomment-1137284360
#[derive(Default, Debug, Clone, Copy, Eq, PartialEq)]
pub struct FloatTypeWrapper(u64);
impl FloatTypeWrapper {
pub fn new(value: f64) -> Self {
Self(value.to_bits())
}
pub fn into_f64(self) -> f64 {
f64::from_bits(self.0)
}
pub fn into_f32(self) -> f32 {
f64::from_bits(self.0) as f32
}
}
impl fmt::Display for FloatTypeWrapper {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{:?}", f64::from_bits(self.0))
}
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Literal {
String(Box<str>),
ByteString(Box<[u8]>),
CString(Box<[u8]>),
Char(char),
Bool(bool),
Int(i128, Option<BuiltinInt>),
Uint(u128, Option<BuiltinUint>),
// Here we are using a wrapper around float because f32 and f64 do not implement Eq, so they
// could not be used directly here, to understand how the wrapper works go to definition of
// FloatTypeWrapper
Float(FloatTypeWrapper, Option<BuiltinFloat>),
}
#[derive(Debug, Clone, Eq, PartialEq)]
/// Used in range patterns.
pub enum LiteralOrConst {
Literal(Literal),
Const(Path),
}
impl Literal {
pub fn negate(self) -> Option<Self> {
if let Literal::Int(i, k) = self {
Some(Literal::Int(-i, k))
} else {
None
}
}
}
impl From<ast::LiteralKind> for Literal {
fn from(ast_lit_kind: ast::LiteralKind) -> Self {
use ast::LiteralKind;
match ast_lit_kind {
// FIXME: these should have actual values filled in, but unsure on perf impact
LiteralKind::IntNumber(lit) => {
if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
Literal::Float(
FloatTypeWrapper::new(lit.float_value().unwrap_or(Default::default())),
builtin,
)
} else if let builtin @ Some(_) = lit.suffix().and_then(BuiltinUint::from_suffix) {
Literal::Uint(lit.value().unwrap_or(0), builtin)
} else {
let builtin = lit.suffix().and_then(BuiltinInt::from_suffix);
Literal::Int(lit.value().unwrap_or(0) as i128, builtin)
}
}
LiteralKind::FloatNumber(lit) => {
let ty = lit.suffix().and_then(BuiltinFloat::from_suffix);
Literal::Float(FloatTypeWrapper::new(lit.value().unwrap_or(Default::default())), ty)
}
LiteralKind::ByteString(bs) => {
let text = bs.value().map(Box::from).unwrap_or_else(Default::default);
Literal::ByteString(text)
}
LiteralKind::String(s) => {
let text = s.value().map(Box::from).unwrap_or_else(Default::default);
Literal::String(text)
}
LiteralKind::CString(s) => {
let text = s.value().map(Box::from).unwrap_or_else(Default::default);
Literal::CString(text)
}
LiteralKind::Byte(b) => {
Literal::Uint(b.value().unwrap_or_default() as u128, Some(BuiltinUint::U8))
}
LiteralKind::Char(c) => Literal::Char(c.value().unwrap_or_default()),
LiteralKind::Bool(val) => Literal::Bool(val),
}
}
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Expr {
/// This is produced if the syntax tree does not have a required expression piece.
Missing,
Path(Path),
If {
condition: ExprId,
then_branch: ExprId,
else_branch: Option<ExprId>,
},
Let {
pat: PatId,
expr: ExprId,
},
Block {
id: Option<BlockId>,
statements: Box<[Statement]>,
tail: Option<ExprId>,
label: Option<LabelId>,
},
Async {
id: Option<BlockId>,
statements: Box<[Statement]>,
tail: Option<ExprId>,
},
Const(ConstBlockId),
Unsafe {
id: Option<BlockId>,
statements: Box<[Statement]>,
tail: Option<ExprId>,
},
Loop {
body: ExprId,
label: Option<LabelId>,
},
While {
condition: ExprId,
body: ExprId,
label: Option<LabelId>,
},
Call {
callee: ExprId,
args: Box<[ExprId]>,
is_assignee_expr: bool,
},
MethodCall {
receiver: ExprId,
method_name: Name,
args: Box<[ExprId]>,
generic_args: Option<Box<GenericArgs>>,
},
Match {
expr: ExprId,
arms: Box<[MatchArm]>,
},
Continue {
label: Option<LabelId>,
},
Break {
expr: Option<ExprId>,
label: Option<LabelId>,
},
Return {
expr: Option<ExprId>,
},
Yield {
expr: Option<ExprId>,
},
Yeet {
expr: Option<ExprId>,
},
RecordLit {
path: Option<Box<Path>>,
fields: Box<[RecordLitField]>,
spread: Option<ExprId>,
ellipsis: bool,
is_assignee_expr: bool,
},
Field {
expr: ExprId,
name: Name,
},
Await {
expr: ExprId,
},
Cast {
expr: ExprId,
type_ref: Interned<TypeRef>,
},
Ref {
expr: ExprId,
rawness: Rawness,
mutability: Mutability,
},
Box {
expr: ExprId,
},
UnaryOp {
expr: ExprId,
op: UnaryOp,
},
BinaryOp {
lhs: ExprId,
rhs: ExprId,
op: Option<BinaryOp>,
},
Range {
lhs: Option<ExprId>,
rhs: Option<ExprId>,
range_type: RangeOp,
},
Index {
base: ExprId,
index: ExprId,
},
Closure {
args: Box<[PatId]>,
arg_types: Box<[Option<Interned<TypeRef>>]>,
ret_type: Option<Interned<TypeRef>>,
body: ExprId,
closure_kind: ClosureKind,
capture_by: CaptureBy,
},
Tuple {
exprs: Box<[ExprId]>,
is_assignee_expr: bool,
},
Array(Array),
Literal(Literal),
Underscore,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ClosureKind {
Closure,
Generator(Movability),
Async,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum CaptureBy {
/// `move |x| y + x`.
Value,
/// `move` keyword was not specified.
Ref,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Movability {
Static,
Movable,
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Array {
ElementList { elements: Box<[ExprId]>, is_assignee_expr: bool },
Repeat { initializer: ExprId, repeat: ExprId },
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct MatchArm {
pub pat: 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<Interned<TypeRef>>,
initializer: Option<ExprId>,
else_branch: Option<ExprId>,
},
Expr {
expr: ExprId,
has_semi: bool,
},
}
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::Let { expr, .. } => {
f(*expr);
}
Expr::Const(_) => (),
Expr::Block { statements, tail, .. }
| Expr::Unsafe { statements, tail, .. }
| Expr::Async { statements, tail, .. } => {
for stmt in statements.iter() {
match stmt {
Statement::Let { initializer, else_branch, .. } => {
if let &Some(expr) = initializer {
f(expr);
}
if let &Some(expr) = else_branch {
f(expr);
}
}
Statement::Expr { expr: expression, .. } => f(*expression),
}
}
if let &Some(expr) = tail {
f(expr);
}
}
Expr::Loop { body, .. } => f(*body),
Expr::While { condition, body, .. } => {
f(*condition);
f(*body);
}
Expr::Call { callee, args, .. } => {
f(*callee);
args.iter().copied().for_each(f);
}
Expr::MethodCall { receiver, args, .. } => {
f(*receiver);
args.iter().copied().for_each(f);
}
Expr::Match { expr, arms } => {
f(*expr);
arms.iter().map(|arm| arm.expr).for_each(f);
}
Expr::Continue { .. } => {}
Expr::Break { expr, .. }
| Expr::Return { expr }
| Expr::Yield { expr }
| Expr::Yeet { expr } => {
if let &Some(expr) = expr {
f(expr);
}
}
Expr::RecordLit { fields, spread, .. } => {
for field in fields.iter() {
f(field.expr);
}
if let &Some(expr) = spread {
f(expr);
}
}
Expr::Closure { body, .. } => {
f(*body);
}
Expr::BinaryOp { lhs, rhs, .. } => {
f(*lhs);
f(*rhs);
}
Expr::Range { lhs, rhs, .. } => {
if let &Some(lhs) = rhs {
f(lhs);
}
if let &Some(rhs) = lhs {
f(rhs);
}
}
Expr::Index { base, index } => {
f(*base);
f(*index);
}
Expr::Field { expr, .. }
| Expr::Await { expr }
| Expr::Cast { expr, .. }
| Expr::Ref { expr, .. }
| Expr::UnaryOp { expr, .. }
| Expr::Box { expr } => {
f(*expr);
}
Expr::Tuple { exprs, .. } => exprs.iter().copied().for_each(f),
Expr::Array(a) => match a {
Array::ElementList { elements, .. } => elements.iter().copied().for_each(f),
Array::Repeat { initializer, repeat } => {
f(*initializer);
f(*repeat)
}
},
Expr::Literal(_) => {}
Expr::Underscore => {}
}
}
}
/// 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 {
pub 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 enum BindingProblems {
/// https://doc.rust-lang.org/stable/error_codes/E0416.html
BoundMoreThanOnce,
/// https://doc.rust-lang.org/stable/error_codes/E0409.html
BoundInconsistently,
/// https://doc.rust-lang.org/stable/error_codes/E0408.html
NotBoundAcrossAll,
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Binding {
pub name: Name,
pub mode: BindingAnnotation,
pub definitions: SmallVec<[PatId; 1]>,
pub problems: Option<BindingProblems>,
}
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct RecordFieldPat {
pub name: Name,
pub pat: PatId,
}
/// Close relative to rustc's hir::PatKind
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum Pat {
Missing,
Wild,
Tuple { args: Box<[PatId]>, ellipsis: Option<usize> },
Or(Box<[PatId]>),
Record { path: Option<Box<Path>>, args: Box<[RecordFieldPat]>, ellipsis: bool },
Range { start: Option<Box<LiteralOrConst>>, end: Option<Box<LiteralOrConst>> },
Slice { prefix: Box<[PatId]>, slice: Option<PatId>, suffix: Box<[PatId]> },
Path(Box<Path>),
Lit(ExprId),
Bind { id: BindingId, subpat: Option<PatId> },
TupleStruct { path: Option<Box<Path>>, args: Box<[PatId]>, ellipsis: Option<usize> },
Ref { pat: PatId, mutability: Mutability },
Box { inner: PatId },
ConstBlock(ExprId),
}
impl Pat {
pub fn walk_child_pats(&self, mut f: impl FnMut(PatId)) {
match self {
Pat::Range { .. }
| Pat::Lit(..)
| Pat::Path(..)
| Pat::ConstBlock(..)
| Pat::Wild
| Pat::Missing => {}
Pat::Bind { subpat, .. } => {
subpat.iter().copied().for_each(f);
}
Pat::Or(args) | Pat::Tuple { args, .. } | Pat::TupleStruct { args, .. } => {
args.iter().copied().for_each(f);
}
Pat::Ref { pat, .. } => f(*pat),
Pat::Slice { prefix, slice, suffix } => {
let total_iter = prefix.iter().chain(slice.iter()).chain(suffix.iter());
total_iter.copied().for_each(f);
}
Pat::Record { args, .. } => {
args.iter().map(|f| f.pat).for_each(f);
}
Pat::Box { inner } => f(*inner),
}
}
}