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rust-analyzer/crates/hir-def/src/expr_store/lower.rs
Lukas Wirth cb6ddbedb0 refactor: Fold hygiene map into bindings themselves 
`HygieneId` fits into `Binding`'s padding.
2025-04-21 16:53:06 +02:00

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//! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
//! representation.
mod asm;
mod generics;
mod path;
use std::mem;
use either::Either;
use hir_expand::{
HirFileId, InFile, Lookup, MacroDefId,
mod_path::tool_path,
name::{AsName, Name},
};
use intern::{Symbol, sym};
use rustc_hash::FxHashMap;
use stdx::never;
use syntax::{
AstNode, AstPtr, AstToken as _, SyntaxNodePtr,
ast::{
self, ArrayExprKind, AstChildren, BlockExpr, HasArgList, HasAttrs, HasGenericArgs,
HasGenericParams, HasLoopBody, HasName, HasTypeBounds, IsString, RangeItem,
SlicePatComponents,
},
};
use thin_vec::ThinVec;
use triomphe::Arc;
use tt::TextRange;
use crate::{
AdtId, BlockId, BlockLoc, DefWithBodyId, FunctionId, GenericDefId, ImplId, ItemTreeLoc,
MacroId, ModuleDefId, ModuleId, TraitAliasId, TraitId, TypeAliasId, UnresolvedMacro,
builtin_type::BuiltinUint,
db::DefDatabase,
expr_store::{
Body, BodySourceMap, ExprPtr, ExpressionStore, ExpressionStoreBuilder,
ExpressionStoreDiagnostics, ExpressionStoreSourceMap, HygieneId, LabelPtr, PatPtr, TypePtr,
expander::Expander,
path::{AssociatedTypeBinding, GenericArg, GenericArgs, GenericArgsParentheses, Path},
},
hir::{
Array, Binding, BindingAnnotation, BindingId, BindingProblems, CaptureBy, ClosureKind,
Expr, ExprId, Item, Label, LabelId, Literal, MatchArm, Movability, OffsetOf, Pat, PatId,
RecordFieldPat, RecordLitField, Statement,
format_args::{
self, FormatAlignment, FormatArgs, FormatArgsPiece, FormatArgument, FormatArgumentKind,
FormatArgumentsCollector, FormatCount, FormatDebugHex, FormatOptions,
FormatPlaceholder, FormatSign, FormatTrait,
},
generics::GenericParams,
},
item_scope::BuiltinShadowMode,
item_tree::FieldsShape,
lang_item::LangItem,
nameres::{DefMap, LocalDefMap, MacroSubNs},
type_ref::{
ArrayType, ConstRef, FnType, LifetimeRef, Mutability, PathId, Rawness, RefType,
TraitBoundModifier, TraitRef, TypeBound, TypeRef, TypeRefId, UseArgRef,
},
};
pub use self::path::hir_segment_to_ast_segment;
type FxIndexSet<K> = indexmap::IndexSet<K, std::hash::BuildHasherDefault<rustc_hash::FxHasher>>;
pub(super) fn lower_body(
db: &dyn DefDatabase,
owner: DefWithBodyId,
current_file_id: HirFileId,
module: ModuleId,
parameters: Option<ast::ParamList>,
body: Option<ast::Expr>,
is_async_fn: bool,
) -> (Body, BodySourceMap) {
// We cannot leave the root span map empty and let any identifier from it be treated as root,
// because when inside nested macros `SyntaxContextId`s from the outer macro will be interleaved
// with the inner macro, and that will cause confusion because they won't be the same as `ROOT`
// even though they should be the same. Also, when the body comes from multiple expansions, their
// hygiene is different.
let krate = module.krate();
let mut self_param = None;
let mut source_map_self_param = None;
let mut params = vec![];
let mut collector = ExprCollector::new(db, module, current_file_id);
let skip_body = match owner {
DefWithBodyId::FunctionId(it) => db.attrs(it.into()),
DefWithBodyId::StaticId(it) => db.attrs(it.into()),
DefWithBodyId::ConstId(it) => db.attrs(it.into()),
DefWithBodyId::VariantId(it) => db.attrs(it.into()),
}
.rust_analyzer_tool()
.any(|attr| *attr.path() == tool_path![skip]);
// If #[rust_analyzer::skip] annotated, only construct enough information for the signature
// and skip the body.
if skip_body {
if let Some(param_list) = parameters {
if let Some(self_param_syn) = param_list
.self_param()
.filter(|self_param| collector.expander.is_cfg_enabled(db, krate, self_param))
{
let is_mutable =
self_param_syn.mut_token().is_some() && self_param_syn.amp_token().is_none();
let hygiene = self_param_syn
.name()
.map(|name| collector.hygiene_id_for(name.syntax().text_range()))
.unwrap_or(HygieneId::ROOT);
let binding_id: la_arena::Idx<Binding> = collector.alloc_binding(
Name::new_symbol_root(sym::self_),
BindingAnnotation::new(is_mutable, false),
hygiene,
);
self_param = Some(binding_id);
source_map_self_param =
Some(collector.expander.in_file(AstPtr::new(&self_param_syn)));
}
let count = param_list
.params()
.filter(|it| collector.expander.is_cfg_enabled(db, krate, it))
.count();
params = (0..count).map(|_| collector.missing_pat()).collect();
};
let body_expr = collector.missing_expr();
return (
Body {
store: collector.store.finish(),
params: params.into_boxed_slice(),
self_param,
body_expr,
},
BodySourceMap { self_param: source_map_self_param, store: collector.source_map },
);
}
if let Some(param_list) = parameters {
if let Some(self_param_syn) =
param_list.self_param().filter(|it| collector.expander.is_cfg_enabled(db, krate, it))
{
let is_mutable =
self_param_syn.mut_token().is_some() && self_param_syn.amp_token().is_none();
let hygiene = self_param_syn
.name()
.map(|name| collector.hygiene_id_for(name.syntax().text_range()))
.unwrap_or(HygieneId::ROOT);
let binding_id: la_arena::Idx<Binding> = collector.alloc_binding(
Name::new_symbol_root(sym::self_),
BindingAnnotation::new(is_mutable, false),
hygiene,
);
self_param = Some(binding_id);
source_map_self_param = Some(collector.expander.in_file(AstPtr::new(&self_param_syn)));
}
for param in param_list.params() {
if collector.expander.is_cfg_enabled(db, krate, &param) {
let param_pat = collector.collect_pat_top(param.pat());
params.push(param_pat);
}
}
};
let body_expr = collector.collect(
body,
if is_async_fn {
Awaitable::Yes
} else {
match owner {
DefWithBodyId::FunctionId(..) => Awaitable::No("non-async function"),
DefWithBodyId::StaticId(..) => Awaitable::No("static"),
DefWithBodyId::ConstId(..) => Awaitable::No("constant"),
DefWithBodyId::VariantId(..) => Awaitable::No("enum variant"),
}
},
);
(
Body {
store: collector.store.finish(),
params: params.into_boxed_slice(),
self_param,
body_expr,
},
BodySourceMap { self_param: source_map_self_param, store: collector.source_map },
)
}
pub(crate) fn lower_type_ref(
db: &dyn DefDatabase,
module: ModuleId,
type_ref: InFile<Option<ast::Type>>,
) -> (ExpressionStore, ExpressionStoreSourceMap, TypeRefId) {
let mut expr_collector = ExprCollector::new(db, module, type_ref.file_id);
let type_ref = expr_collector.lower_type_ref_opt(type_ref.value, &mut TypeRef::ImplTrait);
(expr_collector.store.finish(), expr_collector.source_map, type_ref)
}
pub(crate) fn lower_generic_params(
db: &dyn DefDatabase,
module: ModuleId,
def: GenericDefId,
file_id: HirFileId,
param_list: Option<ast::GenericParamList>,
where_clause: Option<ast::WhereClause>,
) -> (Arc<ExpressionStore>, Arc<GenericParams>, ExpressionStoreSourceMap) {
let mut expr_collector = ExprCollector::new(db, module, file_id);
let mut collector = generics::GenericParamsCollector::new(&mut expr_collector, def);
collector.lower(param_list, where_clause);
let params = collector.finish();
(Arc::new(expr_collector.store.finish()), params, expr_collector.source_map)
}
pub(crate) fn lower_impl(
db: &dyn DefDatabase,
module: ModuleId,
impl_syntax: InFile<ast::Impl>,
impl_id: ImplId,
) -> (ExpressionStore, ExpressionStoreSourceMap, TypeRefId, Option<TraitRef>, Arc<GenericParams>) {
let mut expr_collector = ExprCollector::new(db, module, impl_syntax.file_id);
let self_ty =
expr_collector.lower_type_ref_opt_disallow_impl_trait(impl_syntax.value.self_ty());
let trait_ = impl_syntax.value.trait_().and_then(|it| match &it {
ast::Type::PathType(path_type) => {
let path = expr_collector.lower_path_type(path_type, &mut |_| TypeRef::Error)?;
Some(TraitRef { path: expr_collector.alloc_path(path, AstPtr::new(&it)) })
}
_ => None,
});
let mut collector = generics::GenericParamsCollector::new(&mut expr_collector, impl_id.into());
collector.lower(impl_syntax.value.generic_param_list(), impl_syntax.value.where_clause());
let params = collector.finish();
(expr_collector.store.finish(), expr_collector.source_map, self_ty, trait_, params)
}
pub(crate) fn lower_trait(
db: &dyn DefDatabase,
module: ModuleId,
trait_syntax: InFile<ast::Trait>,
trait_id: TraitId,
) -> (ExpressionStore, ExpressionStoreSourceMap, Arc<GenericParams>) {
let mut expr_collector = ExprCollector::new(db, module, trait_syntax.file_id);
let mut collector = generics::GenericParamsCollector::new(&mut expr_collector, trait_id.into());
collector.fill_self_param(trait_syntax.value.type_bound_list());
collector.lower(trait_syntax.value.generic_param_list(), trait_syntax.value.where_clause());
let params = collector.finish();
(expr_collector.store.finish(), expr_collector.source_map, params)
}
pub(crate) fn lower_trait_alias(
db: &dyn DefDatabase,
module: ModuleId,
trait_syntax: InFile<ast::TraitAlias>,
trait_id: TraitAliasId,
) -> (ExpressionStore, ExpressionStoreSourceMap, Arc<GenericParams>) {
let mut expr_collector = ExprCollector::new(db, module, trait_syntax.file_id);
let mut collector = generics::GenericParamsCollector::new(&mut expr_collector, trait_id.into());
collector.fill_self_param(trait_syntax.value.type_bound_list());
collector.lower(trait_syntax.value.generic_param_list(), trait_syntax.value.where_clause());
let params = collector.finish();
(expr_collector.store.finish(), expr_collector.source_map, params)
}
pub(crate) fn lower_type_alias(
db: &dyn DefDatabase,
module: ModuleId,
alias: InFile<ast::TypeAlias>,
type_alias_id: TypeAliasId,
) -> (
ExpressionStore,
ExpressionStoreSourceMap,
Arc<GenericParams>,
Box<[TypeBound]>,
Option<TypeRefId>,
) {
let mut expr_collector = ExprCollector::new(db, module, alias.file_id);
let bounds = alias
.value
.type_bound_list()
.map(|bounds| {
bounds
.bounds()
.map(|bound| expr_collector.lower_type_bound(bound, &mut TypeRef::ImplTrait))
.collect()
})
.unwrap_or_default();
let mut collector =
generics::GenericParamsCollector::new(&mut expr_collector, type_alias_id.into());
collector.lower(alias.value.generic_param_list(), alias.value.where_clause());
let params = collector.finish();
let type_ref =
alias.value.ty().map(|ty| expr_collector.lower_type_ref(ty, &mut TypeRef::ImplTrait));
(expr_collector.store.finish(), expr_collector.source_map, params, bounds, type_ref)
}
pub(crate) fn lower_function(
db: &dyn DefDatabase,
module: ModuleId,
fn_: InFile<ast::Fn>,
function_id: FunctionId,
) -> (
ExpressionStore,
ExpressionStoreSourceMap,
Arc<GenericParams>,
Box<[TypeRefId]>,
Option<TypeRefId>,
bool,
bool,
) {
let mut expr_collector = ExprCollector::new(db, module, fn_.file_id);
let mut collector =
generics::GenericParamsCollector::new(&mut expr_collector, function_id.into());
collector.lower(fn_.value.generic_param_list(), fn_.value.where_clause());
let mut params = vec![];
let mut has_self_param = false;
let mut has_variadic = false;
collector.collect_impl_trait(|collector, mut impl_trait_lower_fn| {
if let Some(param_list) = fn_.value.param_list() {
if let Some(param) = param_list.self_param() {
let enabled = collector.expander.is_cfg_enabled(db, module.krate(), &param);
if enabled {
has_self_param = true;
params.push(match param.ty() {
Some(ty) => collector.lower_type_ref(ty, &mut impl_trait_lower_fn),
None => {
let self_type = collector.alloc_type_ref_desugared(TypeRef::Path(
Name::new_symbol_root(sym::Self_).into(),
));
let lifetime = param
.lifetime()
.map(|lifetime| collector.lower_lifetime_ref(lifetime));
match param.kind() {
ast::SelfParamKind::Owned => self_type,
ast::SelfParamKind::Ref => collector.alloc_type_ref_desugared(
TypeRef::Reference(Box::new(RefType {
ty: self_type,
lifetime,
mutability: Mutability::Shared,
})),
),
ast::SelfParamKind::MutRef => collector.alloc_type_ref_desugared(
TypeRef::Reference(Box::new(RefType {
ty: self_type,
lifetime,
mutability: Mutability::Mut,
})),
),
}
}
});
}
}
let p = param_list
.params()
.filter(|param| collector.expander.is_cfg_enabled(db, module.krate(), param))
.filter(|param| {
let is_variadic = param.dotdotdot_token().is_some();
has_variadic |= is_variadic;
!is_variadic
})
.map(|param| param.ty())
// FIXME
.collect::<Vec<_>>();
for p in p {
params.push(collector.lower_type_ref_opt(p, &mut impl_trait_lower_fn));
}
}
});
let generics = collector.finish();
let return_type = fn_
.value
.ret_type()
.map(|ret_type| expr_collector.lower_type_ref_opt(ret_type.ty(), &mut TypeRef::ImplTrait));
let return_type = if fn_.value.async_token().is_some() {
let path = hir_expand::mod_path::path![core::future::Future];
let mut generic_args: Vec<_> =
std::iter::repeat_n(None, path.segments().len() - 1).collect();
let binding = AssociatedTypeBinding {
name: Name::new_symbol_root(sym::Output),
args: None,
type_ref: Some(
return_type
.unwrap_or_else(|| expr_collector.alloc_type_ref_desugared(TypeRef::unit())),
),
bounds: Box::default(),
};
generic_args
.push(Some(GenericArgs { bindings: Box::new([binding]), ..GenericArgs::empty() }));
let path = Path::from_known_path(path, generic_args);
let path = PathId::from_type_ref_unchecked(
expr_collector.alloc_type_ref_desugared(TypeRef::Path(path)),
);
let ty_bound = TypeBound::Path(path, TraitBoundModifier::None);
Some(
expr_collector
.alloc_type_ref_desugared(TypeRef::ImplTrait(ThinVec::from_iter([ty_bound]))),
)
} else {
return_type
};
(
expr_collector.store.finish(),
expr_collector.source_map,
generics,
params.into_boxed_slice(),
return_type,
has_self_param,
has_variadic,
)
}
pub struct ExprCollector<'db> {
db: &'db dyn DefDatabase,
expander: Expander,
def_map: Arc<DefMap>,
local_def_map: Arc<LocalDefMap>,
module: ModuleId,
pub store: ExpressionStoreBuilder,
pub(crate) source_map: ExpressionStoreSourceMap,
// state stuff
// Prevent nested impl traits like `impl Foo<impl Bar>`.
outer_impl_trait: bool,
is_lowering_coroutine: bool,
/// Legacy (`macro_rules!`) macros can have multiple definitions and shadow each other,
/// and we need to find the current definition. So we track the number of definitions we saw.
current_block_legacy_macro_defs_count: FxHashMap<Name, usize>,
current_try_block_label: Option<LabelId>,
label_ribs: Vec<LabelRib>,
current_binding_owner: Option<ExprId>,
awaitable_context: Option<Awaitable>,
}
#[derive(Clone, Debug)]
struct LabelRib {
kind: RibKind,
}
impl LabelRib {
fn new(kind: RibKind) -> Self {
LabelRib { kind }
}
}
#[derive(Clone, Debug, PartialEq, Eq)]
enum RibKind {
Normal(Name, LabelId, HygieneId),
Closure,
Constant,
MacroDef(Box<MacroDefId>),
}
impl RibKind {
/// This rib forbids referring to labels defined in upwards ribs.
fn is_label_barrier(&self) -> bool {
match self {
RibKind::Normal(..) | RibKind::MacroDef(_) => false,
RibKind::Closure | RibKind::Constant => true,
}
}
}
#[derive(PartialEq, Eq, Debug, Copy, Clone)]
enum Awaitable {
Yes,
No(&'static str),
}
#[derive(Debug, Default)]
struct BindingList {
map: FxHashMap<(Name, HygieneId), BindingId>,
is_used: FxHashMap<BindingId, bool>,
reject_new: bool,
}
impl BindingList {
fn find(
&mut self,
ec: &mut ExprCollector<'_>,
name: Name,
hygiene: HygieneId,
mode: BindingAnnotation,
) -> BindingId {
let id = *self
.map
.entry((name, hygiene))
.or_insert_with_key(|(name, hygiene)| ec.alloc_binding(name.clone(), mode, *hygiene));
if ec.store.bindings[id].mode != mode {
ec.store.bindings[id].problems = Some(BindingProblems::BoundInconsistently);
}
self.check_is_used(ec, id);
id
}
fn check_is_used(&mut self, ec: &mut ExprCollector<'_>, id: BindingId) {
match self.is_used.get(&id) {
None => {
if self.reject_new {
ec.store.bindings[id].problems = Some(BindingProblems::NotBoundAcrossAll);
}
}
Some(true) => {
ec.store.bindings[id].problems = Some(BindingProblems::BoundMoreThanOnce);
}
Some(false) => {}
}
self.is_used.insert(id, true);
}
}
impl ExprCollector<'_> {
pub fn new(
db: &dyn DefDatabase,
module: ModuleId,
current_file_id: HirFileId,
) -> ExprCollector<'_> {
let (def_map, local_def_map) = module.local_def_map(db);
let expander = Expander::new(db, current_file_id, &def_map);
ExprCollector {
db,
module,
def_map,
local_def_map,
source_map: ExpressionStoreSourceMap::default(),
store: ExpressionStoreBuilder::default(),
expander,
current_try_block_label: None,
is_lowering_coroutine: false,
label_ribs: Vec::new(),
current_binding_owner: None,
awaitable_context: None,
current_block_legacy_macro_defs_count: FxHashMap::default(),
outer_impl_trait: false,
}
}
pub fn lower_lifetime_ref(&mut self, lifetime: ast::Lifetime) -> LifetimeRef {
// FIXME: Keyword check?
match &*lifetime.text() {
"" | "'" => LifetimeRef::Error,
"'static" => LifetimeRef::Static,
"'_" => LifetimeRef::Placeholder,
text => LifetimeRef::Named(Name::new_lifetime(text)),
}
}
pub fn lower_lifetime_ref_opt(&mut self, lifetime: Option<ast::Lifetime>) -> LifetimeRef {
match lifetime {
Some(lifetime) => self.lower_lifetime_ref(lifetime),
None => LifetimeRef::Placeholder,
}
}
/// Converts an `ast::TypeRef` to a `hir::TypeRef`.
pub fn lower_type_ref(
&mut self,
node: ast::Type,
impl_trait_lower_fn: &mut impl FnMut(ThinVec<TypeBound>) -> TypeRef,
) -> TypeRefId {
let ty = match &node {
ast::Type::ParenType(inner) => {
return self.lower_type_ref_opt(inner.ty(), impl_trait_lower_fn);
}
ast::Type::TupleType(inner) => TypeRef::Tuple(ThinVec::from_iter(Vec::from_iter(
inner.fields().map(|it| self.lower_type_ref(it, impl_trait_lower_fn)),
))),
ast::Type::NeverType(..) => TypeRef::Never,
ast::Type::PathType(inner) => inner
.path()
.and_then(|it| self.lower_path(it, impl_trait_lower_fn))
.map(TypeRef::Path)
.unwrap_or(TypeRef::Error),
ast::Type::PtrType(inner) => {
let inner_ty = self.lower_type_ref_opt(inner.ty(), impl_trait_lower_fn);
let mutability = Mutability::from_mutable(inner.mut_token().is_some());
TypeRef::RawPtr(inner_ty, mutability)
}
ast::Type::ArrayType(inner) => {
let len = self.lower_const_arg_opt(inner.const_arg());
TypeRef::Array(ArrayType {
ty: self.lower_type_ref_opt(inner.ty(), impl_trait_lower_fn),
len,
})
}
ast::Type::SliceType(inner) => {
TypeRef::Slice(self.lower_type_ref_opt(inner.ty(), impl_trait_lower_fn))
}
ast::Type::RefType(inner) => {
let inner_ty = self.lower_type_ref_opt(inner.ty(), impl_trait_lower_fn);
let lifetime = inner.lifetime().map(|lt| self.lower_lifetime_ref(lt));
let mutability = Mutability::from_mutable(inner.mut_token().is_some());
TypeRef::Reference(Box::new(RefType { ty: inner_ty, lifetime, mutability }))
}
ast::Type::InferType(_inner) => TypeRef::Placeholder,
ast::Type::FnPtrType(inner) => {
let ret_ty = inner
.ret_type()
.and_then(|rt| rt.ty())
.map(|it| self.lower_type_ref(it, impl_trait_lower_fn))
.unwrap_or_else(|| self.alloc_type_ref_desugared(TypeRef::unit()));
let mut is_varargs = false;
let mut params = if let Some(pl) = inner.param_list() {
if let Some(param) = pl.params().last() {
is_varargs = param.dotdotdot_token().is_some();
}
pl.params()
.map(|it| {
let type_ref = self.lower_type_ref_opt(it.ty(), impl_trait_lower_fn);
let name = match it.pat() {
Some(ast::Pat::IdentPat(it)) => Some(
it.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing),
),
_ => None,
};
(name, type_ref)
})
.collect()
} else {
Vec::with_capacity(1)
};
fn lower_abi(abi: ast::Abi) -> Symbol {
match abi.abi_string() {
Some(tok) => Symbol::intern(tok.text_without_quotes()),
// `extern` default to be `extern "C"`.
_ => sym::C,
}
}
let abi = inner.abi().map(lower_abi);
params.push((None, ret_ty));
TypeRef::Fn(Box::new(FnType {
is_varargs,
is_unsafe: inner.unsafe_token().is_some(),
abi,
params: params.into_boxed_slice(),
}))
}
// for types are close enough for our purposes to the inner type for now...
ast::Type::ForType(inner) => {
return self.lower_type_ref_opt(inner.ty(), impl_trait_lower_fn);
}
ast::Type::ImplTraitType(inner) => {
if self.outer_impl_trait {
// Disallow nested impl traits
TypeRef::Error
} else {
self.with_outer_impl_trait_scope(true, |this| {
let type_bounds =
this.type_bounds_from_ast(inner.type_bound_list(), impl_trait_lower_fn);
impl_trait_lower_fn(type_bounds)
})
}
}
ast::Type::DynTraitType(inner) => TypeRef::DynTrait(
self.type_bounds_from_ast(inner.type_bound_list(), impl_trait_lower_fn),
),
ast::Type::MacroType(mt) => match mt.macro_call() {
Some(mcall) => {
let macro_ptr = AstPtr::new(&mcall);
let src = self.expander.in_file(AstPtr::new(&node));
let id = self.collect_macro_call(mcall, macro_ptr, true, |this, expansion| {
this.lower_type_ref_opt(expansion, impl_trait_lower_fn)
});
self.source_map.types_map.insert(src, id);
return id;
}
None => TypeRef::Error,
},
};
self.alloc_type_ref(ty, AstPtr::new(&node))
}
pub(crate) fn lower_type_ref_disallow_impl_trait(&mut self, node: ast::Type) -> TypeRefId {
self.lower_type_ref(node, &mut |_| TypeRef::Error)
}
pub(crate) fn lower_type_ref_opt(
&mut self,
node: Option<ast::Type>,
impl_trait_lower_fn: &mut impl FnMut(ThinVec<TypeBound>) -> TypeRef,
) -> TypeRefId {
match node {
Some(node) => self.lower_type_ref(node, impl_trait_lower_fn),
None => self.alloc_error_type(),
}
}
pub(crate) fn lower_type_ref_opt_disallow_impl_trait(
&mut self,
node: Option<ast::Type>,
) -> TypeRefId {
self.lower_type_ref_opt(node, &mut |_| TypeRef::Error)
}
fn alloc_type_ref(&mut self, type_ref: TypeRef, node: TypePtr) -> TypeRefId {
let id = self.store.types.alloc(type_ref);
let ptr = self.expander.in_file(node);
self.source_map.types_map_back.insert(id, ptr);
self.source_map.types_map.insert(ptr, id);
id
}
pub fn lower_path(
&mut self,
ast: ast::Path,
impl_trait_lower_fn: &mut impl FnMut(ThinVec<TypeBound>) -> TypeRef,
) -> Option<Path> {
super::lower::path::lower_path(self, ast, impl_trait_lower_fn)
}
fn with_outer_impl_trait_scope<R>(
&mut self,
impl_trait: bool,
f: impl FnOnce(&mut Self) -> R,
) -> R {
let old = mem::replace(&mut self.outer_impl_trait, impl_trait);
let result = f(self);
self.outer_impl_trait = old;
result
}
fn alloc_type_ref_desugared(&mut self, type_ref: TypeRef) -> TypeRefId {
self.store.types.alloc(type_ref)
}
fn alloc_error_type(&mut self) -> TypeRefId {
self.store.types.alloc(TypeRef::Error)
}
fn alloc_path(&mut self, path: Path, node: TypePtr) -> PathId {
PathId::from_type_ref_unchecked(self.alloc_type_ref(TypeRef::Path(path), node))
}
/// Collect `GenericArgs` from the parts of a fn-like path, i.e. `Fn(X, Y)
/// -> Z` (which desugars to `Fn<(X, Y), Output=Z>`).
pub fn lower_generic_args_from_fn_path(
&mut self,
args: Option<ast::ParenthesizedArgList>,
ret_type: Option<ast::RetType>,
impl_trait_lower_fn: &mut impl FnMut(ThinVec<TypeBound>) -> TypeRef,
) -> Option<GenericArgs> {
let params = args?;
let mut param_types = Vec::new();
for param in params.type_args() {
let type_ref = self.lower_type_ref_opt(param.ty(), impl_trait_lower_fn);
param_types.push(type_ref);
}
let args = Box::new([GenericArg::Type(
self.alloc_type_ref_desugared(TypeRef::Tuple(ThinVec::from_iter(param_types))),
)]);
let bindings = if let Some(ret_type) = ret_type {
let type_ref = self.lower_type_ref_opt(ret_type.ty(), impl_trait_lower_fn);
Box::new([AssociatedTypeBinding {
name: Name::new_symbol_root(sym::Output),
args: None,
type_ref: Some(type_ref),
bounds: Box::default(),
}])
} else {
// -> ()
let type_ref = self.alloc_type_ref_desugared(TypeRef::unit());
Box::new([AssociatedTypeBinding {
name: Name::new_symbol_root(sym::Output),
args: None,
type_ref: Some(type_ref),
bounds: Box::default(),
}])
};
Some(GenericArgs {
args,
has_self_type: false,
bindings,
parenthesized: GenericArgsParentheses::ParenSugar,
})
}
pub(super) fn lower_generic_args(
&mut self,
node: ast::GenericArgList,
impl_trait_lower_fn: &mut impl FnMut(ThinVec<TypeBound>) -> TypeRef,
) -> Option<GenericArgs> {
let mut args = Vec::new();
let mut bindings = Vec::new();
for generic_arg in node.generic_args() {
match generic_arg {
ast::GenericArg::TypeArg(type_arg) => {
let type_ref = self.lower_type_ref_opt(type_arg.ty(), impl_trait_lower_fn);
args.push(GenericArg::Type(type_ref));
}
ast::GenericArg::AssocTypeArg(assoc_type_arg) => {
if assoc_type_arg.param_list().is_some() {
// We currently ignore associated return type bounds.
continue;
}
if let Some(name_ref) = assoc_type_arg.name_ref() {
// Nested impl traits like `impl Foo<Assoc = impl Bar>` are allowed
self.with_outer_impl_trait_scope(false, |this| {
let name = name_ref.as_name();
let args = assoc_type_arg
.generic_arg_list()
.and_then(|args| this.lower_generic_args(args, impl_trait_lower_fn))
.or_else(|| {
assoc_type_arg
.return_type_syntax()
.map(|_| GenericArgs::return_type_notation())
});
let type_ref = assoc_type_arg
.ty()
.map(|it| this.lower_type_ref(it, impl_trait_lower_fn));
let bounds = if let Some(l) = assoc_type_arg.type_bound_list() {
l.bounds()
.map(|it| this.lower_type_bound(it, impl_trait_lower_fn))
.collect()
} else {
Box::default()
};
bindings.push(AssociatedTypeBinding { name, args, type_ref, bounds });
});
}
}
ast::GenericArg::LifetimeArg(lifetime_arg) => {
if let Some(lifetime) = lifetime_arg.lifetime() {
let lifetime_ref = self.lower_lifetime_ref(lifetime);
args.push(GenericArg::Lifetime(lifetime_ref))
}
}
ast::GenericArg::ConstArg(arg) => {
let arg = self.lower_const_arg(arg);
args.push(GenericArg::Const(arg))
}
}
}
if args.is_empty() && bindings.is_empty() {
return None;
}
Some(GenericArgs {
args: args.into_boxed_slice(),
has_self_type: false,
bindings: bindings.into_boxed_slice(),
parenthesized: GenericArgsParentheses::No,
})
}
fn collect(&mut self, expr: Option<ast::Expr>, awaitable: Awaitable) -> ExprId {
self.awaitable_context.replace(awaitable);
self.with_label_rib(RibKind::Closure, |this| {
if awaitable == Awaitable::Yes {
match expr {
Some(e) => {
let syntax_ptr = AstPtr::new(&e);
let expr = this.collect_expr(e);
this.alloc_expr_desugared_with_ptr(
Expr::Async { id: None, statements: Box::new([]), tail: Some(expr) },
syntax_ptr,
)
}
None => this.missing_expr(),
}
} else {
this.collect_expr_opt(expr)
}
})
}
fn type_bounds_from_ast(
&mut self,
type_bounds_opt: Option<ast::TypeBoundList>,
impl_trait_lower_fn: &mut impl FnMut(ThinVec<TypeBound>) -> TypeRef,
) -> ThinVec<TypeBound> {
if let Some(type_bounds) = type_bounds_opt {
ThinVec::from_iter(Vec::from_iter(
type_bounds.bounds().map(|it| self.lower_type_bound(it, impl_trait_lower_fn)),
))
} else {
ThinVec::from_iter([])
}
}
fn lower_path_type(
&mut self,
path_type: &ast::PathType,
impl_trait_lower_fn: &mut impl FnMut(ThinVec<TypeBound>) -> TypeRef,
) -> Option<Path> {
let path = self.lower_path(path_type.path()?, impl_trait_lower_fn)?;
Some(path)
}
fn lower_type_bound(
&mut self,
node: ast::TypeBound,
impl_trait_lower_fn: &mut impl FnMut(ThinVec<TypeBound>) -> TypeRef,
) -> TypeBound {
match node.kind() {
ast::TypeBoundKind::PathType(path_type) => {
let m = match node.question_mark_token() {
Some(_) => TraitBoundModifier::Maybe,
None => TraitBoundModifier::None,
};
self.lower_path_type(&path_type, impl_trait_lower_fn)
.map(|p| {
TypeBound::Path(self.alloc_path(p, AstPtr::new(&path_type).upcast()), m)
})
.unwrap_or(TypeBound::Error)
}
ast::TypeBoundKind::ForType(for_type) => {
let lt_refs = match for_type.generic_param_list() {
Some(gpl) => gpl
.lifetime_params()
.flat_map(|lp| lp.lifetime().map(|lt| Name::new_lifetime(&lt.text())))
.collect(),
None => Box::default(),
};
let path = for_type.ty().and_then(|ty| match &ty {
ast::Type::PathType(path_type) => {
self.lower_path_type(path_type, impl_trait_lower_fn).map(|p| (p, ty))
}
_ => None,
});
match path {
Some((p, ty)) => {
TypeBound::ForLifetime(lt_refs, self.alloc_path(p, AstPtr::new(&ty)))
}
None => TypeBound::Error,
}
}
ast::TypeBoundKind::Use(gal) => TypeBound::Use(
gal.use_bound_generic_args()
.map(|p| match p {
ast::UseBoundGenericArg::Lifetime(l) => {
UseArgRef::Lifetime(self.lower_lifetime_ref(l))
}
ast::UseBoundGenericArg::NameRef(n) => UseArgRef::Name(n.as_name()),
})
.collect(),
),
ast::TypeBoundKind::Lifetime(lifetime) => {
TypeBound::Lifetime(self.lower_lifetime_ref(lifetime))
}
}
}
fn lower_const_arg_opt(&mut self, arg: Option<ast::ConstArg>) -> ConstRef {
ConstRef { expr: self.collect_expr_opt(arg.and_then(|it| it.expr())) }
}
fn lower_const_arg(&mut self, arg: ast::ConstArg) -> ConstRef {
ConstRef { expr: self.collect_expr_opt(arg.expr()) }
}
fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
self.maybe_collect_expr(expr).unwrap_or_else(|| self.missing_expr())
}
/// Returns `None` if and only if the expression is `#[cfg]`d out.
fn maybe_collect_expr(&mut self, expr: ast::Expr) -> Option<ExprId> {
let syntax_ptr = AstPtr::new(&expr);
self.check_cfg(&expr)?;
// FIXME: Move some of these arms out into separate methods for clarity
Some(match expr {
ast::Expr::IfExpr(e) => {
let then_branch = self.collect_block_opt(e.then_branch());
let else_branch = e.else_branch().map(|b| match b {
ast::ElseBranch::Block(it) => self.collect_block(it),
ast::ElseBranch::IfExpr(elif) => {
let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
self.collect_expr(expr)
}
});
let condition = self.collect_expr_opt(e.condition());
self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
}
ast::Expr::LetExpr(e) => {
let pat = self.collect_pat_top(e.pat());
let expr = self.collect_expr_opt(e.expr());
self.alloc_expr(Expr::Let { pat, expr }, syntax_ptr)
}
ast::Expr::BlockExpr(e) => match e.modifier() {
Some(ast::BlockModifier::Try(_)) => self.desugar_try_block(e),
Some(ast::BlockModifier::Unsafe(_)) => {
self.collect_block_(e, |id, statements, tail| Expr::Unsafe {
id,
statements,
tail,
})
}
Some(ast::BlockModifier::Label(label)) => {
let label_hygiene = self.hygiene_id_for(label.syntax().text_range());
let label_id = self.collect_label(label);
self.with_labeled_rib(label_id, label_hygiene, |this| {
this.collect_block_(e, |id, statements, tail| Expr::Block {
id,
statements,
tail,
label: Some(label_id),
})
})
}
Some(ast::BlockModifier::Async(_)) => {
self.with_label_rib(RibKind::Closure, |this| {
this.with_awaitable_block(Awaitable::Yes, |this| {
this.collect_block_(e, |id, statements, tail| Expr::Async {
id,
statements,
tail,
})
})
})
}
Some(ast::BlockModifier::Const(_)) => {
self.with_label_rib(RibKind::Constant, |this| {
this.with_awaitable_block(Awaitable::No("constant block"), |this| {
let (result_expr_id, prev_binding_owner) =
this.initialize_binding_owner(syntax_ptr);
let inner_expr = this.collect_block(e);
this.store.exprs[result_expr_id] = Expr::Const(inner_expr);
this.current_binding_owner = prev_binding_owner;
result_expr_id
})
})
}
// FIXME
Some(ast::BlockModifier::AsyncGen(_)) => {
self.with_awaitable_block(Awaitable::Yes, |this| this.collect_block(e))
}
Some(ast::BlockModifier::Gen(_)) => self
.with_awaitable_block(Awaitable::No("non-async gen block"), |this| {
this.collect_block(e)
}),
None => self.collect_block(e),
},
ast::Expr::LoopExpr(e) => {
let label = e.label().map(|label| {
(self.hygiene_id_for(label.syntax().text_range()), self.collect_label(label))
});
let body = self.collect_labelled_block_opt(label, e.loop_body());
self.alloc_expr(Expr::Loop { body, label: label.map(|it| it.1) }, syntax_ptr)
}
ast::Expr::WhileExpr(e) => self.collect_while_loop(syntax_ptr, e),
ast::Expr::ForExpr(e) => self.collect_for_loop(syntax_ptr, e),
ast::Expr::CallExpr(e) => {
let is_rustc_box = {
let attrs = e.attrs();
attrs.filter_map(|it| it.as_simple_atom()).any(|it| it == "rustc_box")
};
if is_rustc_box {
let expr = self.collect_expr_opt(e.arg_list().and_then(|it| it.args().next()));
self.alloc_expr(Expr::Box { expr }, syntax_ptr)
} else {
let callee = self.collect_expr_opt(e.expr());
let args = if let Some(arg_list) = e.arg_list() {
arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
} else {
Box::default()
};
self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
}
}
ast::Expr::MethodCallExpr(e) => {
let receiver = self.collect_expr_opt(e.receiver());
let args = if let Some(arg_list) = e.arg_list() {
arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
} else {
Box::default()
};
let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
let generic_args = e
.generic_arg_list()
.and_then(|it| self.lower_generic_args(it, &mut |_| TypeRef::Error))
.map(Box::new);
self.alloc_expr(
Expr::MethodCall { receiver, method_name, args, generic_args },
syntax_ptr,
)
}
ast::Expr::MatchExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
let arms = if let Some(match_arm_list) = e.match_arm_list() {
match_arm_list
.arms()
.filter_map(|arm| {
self.check_cfg(&arm).map(|()| MatchArm {
pat: self.collect_pat_top(arm.pat()),
expr: self.collect_expr_opt(arm.expr()),
guard: arm
.guard()
.map(|guard| self.collect_expr_opt(guard.condition())),
})
})
.collect()
} else {
Box::default()
};
self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
}
ast::Expr::PathExpr(e) => {
let (path, hygiene) = self
.collect_expr_path(e)
.map(|(path, hygiene)| (Expr::Path(path), hygiene))
.unwrap_or((Expr::Missing, HygieneId::ROOT));
let expr_id = self.alloc_expr(path, syntax_ptr);
if !hygiene.is_root() {
self.store.ident_hygiene.insert(expr_id.into(), hygiene);
}
expr_id
}
ast::Expr::ContinueExpr(e) => {
let label = self.resolve_label(e.lifetime()).unwrap_or_else(|e| {
self.source_map.diagnostics.push(e);
None
});
self.alloc_expr(Expr::Continue { label }, syntax_ptr)
}
ast::Expr::BreakExpr(e) => {
let label = self.resolve_label(e.lifetime()).unwrap_or_else(|e| {
self.source_map.diagnostics.push(e);
None
});
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Break { expr, label }, syntax_ptr)
}
ast::Expr::ParenExpr(e) => {
let inner = self.collect_expr_opt(e.expr());
// make the paren expr point to the inner expression as well for IDE resolution
let src = self.expander.in_file(syntax_ptr);
self.source_map.expr_map.insert(src, inner.into());
inner
}
ast::Expr::ReturnExpr(e) => {
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Return { expr }, syntax_ptr)
}
ast::Expr::BecomeExpr(e) => {
let expr =
e.expr().map(|e| self.collect_expr(e)).unwrap_or_else(|| self.missing_expr());
self.alloc_expr(Expr::Become { expr }, syntax_ptr)
}
ast::Expr::YieldExpr(e) => {
self.is_lowering_coroutine = true;
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
}
ast::Expr::YeetExpr(e) => {
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Yeet { expr }, syntax_ptr)
}
ast::Expr::RecordExpr(e) => {
let path = e
.path()
.and_then(|path| self.lower_path(path, &mut |_| TypeRef::Error))
.map(Box::new);
let record_lit = if let Some(nfl) = e.record_expr_field_list() {
let fields = nfl
.fields()
.filter_map(|field| {
self.check_cfg(&field)?;
let name = field.field_name()?.as_name();
let expr = match field.expr() {
Some(e) => self.collect_expr(e),
None => self.missing_expr(),
};
let src = self.expander.in_file(AstPtr::new(&field));
self.source_map.field_map_back.insert(expr, src);
Some(RecordLitField { name, expr })
})
.collect();
let spread = nfl.spread().map(|s| self.collect_expr(s));
Expr::RecordLit { path, fields, spread }
} else {
Expr::RecordLit { path, fields: Box::default(), spread: None }
};
self.alloc_expr(record_lit, syntax_ptr)
}
ast::Expr::FieldExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
let name = match e.field_access() {
Some(kind) => kind.as_name(),
_ => Name::missing(),
};
self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
}
ast::Expr::AwaitExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
if let Awaitable::No(location) = self.is_lowering_awaitable_block() {
self.source_map.diagnostics.push(
ExpressionStoreDiagnostics::AwaitOutsideOfAsync {
node: self.expander.in_file(AstPtr::new(&e)),
location: location.to_string(),
},
);
}
self.alloc_expr(Expr::Await { expr }, syntax_ptr)
}
ast::Expr::TryExpr(e) => self.collect_try_operator(syntax_ptr, e),
ast::Expr::CastExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
let type_ref = self.lower_type_ref_opt_disallow_impl_trait(e.ty());
self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
}
ast::Expr::RefExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
let raw_tok = e.raw_token().is_some();
let mutability = if raw_tok {
if e.mut_token().is_some() { Mutability::Mut } else { Mutability::Shared }
} else {
Mutability::from_mutable(e.mut_token().is_some())
};
let rawness = Rawness::from_raw(raw_tok);
self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
}
ast::Expr::PrefixExpr(e) => {
let expr = self.collect_expr_opt(e.expr());
match e.op_kind() {
Some(op) => self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr),
None => self.alloc_expr(Expr::Missing, syntax_ptr),
}
}
ast::Expr::ClosureExpr(e) => self.with_label_rib(RibKind::Closure, |this| {
let (result_expr_id, prev_binding_owner) =
this.initialize_binding_owner(syntax_ptr);
let mut args = Vec::new();
let mut arg_types = Vec::new();
if let Some(pl) = e.param_list() {
let num_params = pl.params().count();
args.reserve_exact(num_params);
arg_types.reserve_exact(num_params);
for param in pl.params() {
let pat = this.collect_pat_top(param.pat());
let type_ref =
param.ty().map(|it| this.lower_type_ref_disallow_impl_trait(it));
args.push(pat);
arg_types.push(type_ref);
}
}
let ret_type = e
.ret_type()
.and_then(|r| r.ty())
.map(|it| this.lower_type_ref_disallow_impl_trait(it));
let prev_is_lowering_coroutine = mem::take(&mut this.is_lowering_coroutine);
let prev_try_block_label = this.current_try_block_label.take();
let awaitable = if e.async_token().is_some() {
Awaitable::Yes
} else {
Awaitable::No("non-async closure")
};
let body =
this.with_awaitable_block(awaitable, |this| this.collect_expr_opt(e.body()));
let closure_kind = if this.is_lowering_coroutine {
let movability = if e.static_token().is_some() {
Movability::Static
} else {
Movability::Movable
};
ClosureKind::Coroutine(movability)
} else if e.async_token().is_some() {
ClosureKind::Async
} else {
ClosureKind::Closure
};
let capture_by =
if e.move_token().is_some() { CaptureBy::Value } else { CaptureBy::Ref };
this.is_lowering_coroutine = prev_is_lowering_coroutine;
this.current_binding_owner = prev_binding_owner;
this.current_try_block_label = prev_try_block_label;
this.store.exprs[result_expr_id] = Expr::Closure {
args: args.into(),
arg_types: arg_types.into(),
ret_type,
body,
closure_kind,
capture_by,
};
result_expr_id
}),
ast::Expr::BinExpr(e) => {
let op = e.op_kind();
if let Some(ast::BinaryOp::Assignment { op: None }) = op {
let target = self.collect_expr_as_pat_opt(e.lhs());
let value = self.collect_expr_opt(e.rhs());
self.alloc_expr(Expr::Assignment { target, value }, syntax_ptr)
} else {
let lhs = self.collect_expr_opt(e.lhs());
let rhs = self.collect_expr_opt(e.rhs());
self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
}
}
ast::Expr::TupleExpr(e) => {
let mut exprs: Vec<_> = e.fields().map(|expr| self.collect_expr(expr)).collect();
// if there is a leading comma, the user is most likely to type out a leading expression
// so we insert a missing expression at the beginning for IDE features
if comma_follows_token(e.l_paren_token()) {
exprs.insert(0, self.missing_expr());
}
self.alloc_expr(Expr::Tuple { exprs: exprs.into_boxed_slice() }, syntax_ptr)
}
ast::Expr::ArrayExpr(e) => {
let kind = e.kind();
match kind {
ArrayExprKind::ElementList(e) => {
let elements = e.map(|expr| self.collect_expr(expr)).collect();
self.alloc_expr(Expr::Array(Array::ElementList { elements }), syntax_ptr)
}
ArrayExprKind::Repeat { initializer, repeat } => {
let initializer = self.collect_expr_opt(initializer);
let repeat = self.with_label_rib(RibKind::Constant, |this| {
if let Some(repeat) = repeat {
let syntax_ptr = AstPtr::new(&repeat);
this.collect_as_a_binding_owner_bad(
|this| this.collect_expr(repeat),
syntax_ptr,
)
} else {
this.missing_expr()
}
});
self.alloc_expr(
Expr::Array(Array::Repeat { initializer, repeat }),
syntax_ptr,
)
}
}
}
ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
ast::Expr::IndexExpr(e) => {
let base = self.collect_expr_opt(e.base());
let index = self.collect_expr_opt(e.index());
self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
}
ast::Expr::RangeExpr(e) => {
let lhs = e.start().map(|lhs| self.collect_expr(lhs));
let rhs = e.end().map(|rhs| self.collect_expr(rhs));
match e.op_kind() {
Some(range_type) => {
self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
}
None => self.alloc_expr(Expr::Missing, syntax_ptr),
}
}
ast::Expr::MacroExpr(e) => {
let e = e.macro_call()?;
let macro_ptr = AstPtr::new(&e);
let id = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
expansion.map(|it| this.collect_expr(it))
});
match id {
Some(id) => {
// Make the macro-call point to its expanded expression so we can query
// semantics on syntax pointers to the macro
let src = self.expander.in_file(syntax_ptr);
self.source_map.expr_map.insert(src, id.into());
id
}
None => self.alloc_expr(Expr::Missing, syntax_ptr),
}
}
ast::Expr::UnderscoreExpr(_) => self.alloc_expr(Expr::Underscore, syntax_ptr),
ast::Expr::AsmExpr(e) => self.lower_inline_asm(e, syntax_ptr),
ast::Expr::OffsetOfExpr(e) => {
let container = self.lower_type_ref_opt_disallow_impl_trait(e.ty());
let fields = e.fields().map(|it| it.as_name()).collect();
self.alloc_expr(Expr::OffsetOf(OffsetOf { container, fields }), syntax_ptr)
}
ast::Expr::FormatArgsExpr(f) => self.collect_format_args(f, syntax_ptr),
})
}
fn collect_expr_path(&mut self, e: ast::PathExpr) -> Option<(Path, HygieneId)> {
e.path().and_then(|path| {
let path = self.lower_path(path, &mut |_| TypeRef::Error)?;
// Need to enable `mod_path.len() < 1` for `self`.
let may_be_variable = matches!(&path, Path::BarePath(mod_path) if mod_path.len() <= 1);
let hygiene = if may_be_variable {
self.hygiene_id_for(e.syntax().text_range())
} else {
HygieneId::ROOT
};
Some((path, hygiene))
})
}
fn collect_expr_as_pat_opt(&mut self, expr: Option<ast::Expr>) -> PatId {
match expr {
Some(expr) => self.collect_expr_as_pat(expr),
_ => self.missing_pat(),
}
}
fn collect_expr_as_pat(&mut self, expr: ast::Expr) -> PatId {
self.maybe_collect_expr_as_pat(&expr).unwrap_or_else(|| {
let src = self.expander.in_file(AstPtr::new(&expr).wrap_left());
let expr = self.collect_expr(expr);
// Do not use `alloc_pat_from_expr()` here, it will override the entry in `expr_map`.
let id = self.store.pats.alloc(Pat::Expr(expr));
self.source_map.pat_map_back.insert(id, src);
id
})
}
fn maybe_collect_expr_as_pat(&mut self, expr: &ast::Expr) -> Option<PatId> {
self.check_cfg(expr)?;
let syntax_ptr = AstPtr::new(expr);
let result = match expr {
ast::Expr::UnderscoreExpr(_) => self.alloc_pat_from_expr(Pat::Wild, syntax_ptr),
ast::Expr::ParenExpr(e) => {
// We special-case `(..)` for consistency with patterns.
if let Some(ast::Expr::RangeExpr(range)) = e.expr() {
if range.is_range_full() {
return Some(self.alloc_pat_from_expr(
Pat::Tuple { args: Box::default(), ellipsis: Some(0) },
syntax_ptr,
));
}
}
return e.expr().and_then(|expr| self.maybe_collect_expr_as_pat(&expr));
}
ast::Expr::TupleExpr(e) => {
let (ellipsis, args) = collect_tuple(self, e.fields());
self.alloc_pat_from_expr(Pat::Tuple { args, ellipsis }, syntax_ptr)
}
ast::Expr::ArrayExpr(e) => {
if e.semicolon_token().is_some() {
return None;
}
let mut elements = e.exprs();
let prefix = elements
.by_ref()
.map_while(|elem| collect_possibly_rest(self, elem).left())
.collect();
let suffix = elements.map(|elem| self.collect_expr_as_pat(elem)).collect();
self.alloc_pat_from_expr(Pat::Slice { prefix, slice: None, suffix }, syntax_ptr)
}
ast::Expr::CallExpr(e) => {
let path = collect_path(self, e.expr()?)?;
let path = path
.path()
.and_then(|path| self.lower_path(path, &mut |_| TypeRef::Error))
.map(Box::new);
let (ellipsis, args) = collect_tuple(self, e.arg_list()?.args());
self.alloc_pat_from_expr(Pat::TupleStruct { path, args, ellipsis }, syntax_ptr)
}
ast::Expr::PathExpr(e) => {
let (path, hygiene) = self
.collect_expr_path(e.clone())
.map(|(path, hygiene)| (Pat::Path(path), hygiene))
.unwrap_or((Pat::Missing, HygieneId::ROOT));
let pat_id = self.alloc_pat_from_expr(path, syntax_ptr);
if !hygiene.is_root() {
self.store.ident_hygiene.insert(pat_id.into(), hygiene);
}
pat_id
}
ast::Expr::MacroExpr(e) => {
let e = e.macro_call()?;
let macro_ptr = AstPtr::new(&e);
let src = self.expander.in_file(AstPtr::new(expr));
let id = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
this.collect_expr_as_pat_opt(expansion)
});
self.source_map.expr_map.insert(src, id.into());
id
}
ast::Expr::RecordExpr(e) => {
let path = e
.path()
.and_then(|path| self.lower_path(path, &mut |_| TypeRef::Error))
.map(Box::new);
let record_field_list = e.record_expr_field_list()?;
let ellipsis = record_field_list.dotdot_token().is_some();
// FIXME: Report an error here if `record_field_list.spread().is_some()`.
let args = record_field_list
.fields()
.filter_map(|f| {
self.check_cfg(&f)?;
let field_expr = f.expr()?;
let pat = self.collect_expr_as_pat(field_expr);
let name = f.field_name()?.as_name();
let src = self.expander.in_file(AstPtr::new(&f).wrap_left());
self.source_map.pat_field_map_back.insert(pat, src);
Some(RecordFieldPat { name, pat })
})
.collect();
self.alloc_pat_from_expr(Pat::Record { path, args, ellipsis }, syntax_ptr)
}
_ => return None,
};
return Some(result);
fn collect_path(this: &mut ExprCollector<'_>, expr: ast::Expr) -> Option<ast::PathExpr> {
match expr {
ast::Expr::PathExpr(e) => Some(e),
ast::Expr::MacroExpr(mac) => {
let call = mac.macro_call()?;
{
let macro_ptr = AstPtr::new(&call);
this.collect_macro_call(call, macro_ptr, true, |this, expanded_path| {
collect_path(this, expanded_path?)
})
}
}
_ => None,
}
}
fn collect_possibly_rest(
this: &mut ExprCollector<'_>,
expr: ast::Expr,
) -> Either<PatId, ()> {
match &expr {
ast::Expr::RangeExpr(e) if e.is_range_full() => Either::Right(()),
ast::Expr::MacroExpr(mac) => match mac.macro_call() {
Some(call) => {
let macro_ptr = AstPtr::new(&call);
let pat = this.collect_macro_call(
call,
macro_ptr,
true,
|this, expanded_expr| match expanded_expr {
Some(expanded_pat) => collect_possibly_rest(this, expanded_pat),
None => Either::Left(this.missing_pat()),
},
);
if let Either::Left(pat) = pat {
let src = this.expander.in_file(AstPtr::new(&expr).wrap_left());
this.source_map.pat_map_back.insert(pat, src);
}
pat
}
None => {
let ptr = AstPtr::new(&expr);
Either::Left(this.alloc_pat_from_expr(Pat::Missing, ptr))
}
},
_ => Either::Left(this.collect_expr_as_pat(expr)),
}
}
fn collect_tuple(
this: &mut ExprCollector<'_>,
fields: ast::AstChildren<ast::Expr>,
) -> (Option<u32>, Box<[la_arena::Idx<Pat>]>) {
let mut ellipsis = None;
let args = fields
.enumerate()
.filter_map(|(idx, elem)| {
match collect_possibly_rest(this, elem) {
Either::Left(pat) => Some(pat),
Either::Right(()) => {
if ellipsis.is_none() {
ellipsis = Some(idx as u32);
}
// FIXME: Report an error here otherwise.
None
}
}
})
.collect();
(ellipsis, args)
}
}
fn initialize_binding_owner(
&mut self,
syntax_ptr: AstPtr<ast::Expr>,
) -> (ExprId, Option<ExprId>) {
let result_expr_id = self.alloc_expr(Expr::Missing, syntax_ptr);
let prev_binding_owner = self.current_binding_owner.take();
self.current_binding_owner = Some(result_expr_id);
(result_expr_id, prev_binding_owner)
}
/// FIXME: This function is bad. It will produce a dangling `Missing` expr which wastes memory. Currently
/// it is used only for const blocks and repeat expressions, which are also hacky and ideally should have
/// their own body. Don't add more usage for this function so that we can remove this function after
/// separating those bodies.
fn collect_as_a_binding_owner_bad(
&mut self,
job: impl FnOnce(&mut ExprCollector<'_>) -> ExprId,
syntax_ptr: AstPtr<ast::Expr>,
) -> ExprId {
let (id, prev_owner) = self.initialize_binding_owner(syntax_ptr);
let tmp = job(self);
self.store.exprs[id] = mem::replace(&mut self.store.exprs[tmp], Expr::Missing);
self.current_binding_owner = prev_owner;
id
}
/// Desugar `try { <stmts>; <expr> }` into `'<new_label>: { <stmts>; ::std::ops::Try::from_output(<expr>) }`,
/// `try { <stmts>; }` into `'<new_label>: { <stmts>; ::std::ops::Try::from_output(()) }`
/// and save the `<new_label>` to use it as a break target for desugaring of the `?` operator.
fn desugar_try_block(&mut self, e: BlockExpr) -> ExprId {
let try_from_output = self.lang_path(LangItem::TryTraitFromOutput);
let label = self.alloc_label_desugared(Label {
name: Name::generate_new_name(self.store.labels.len()),
});
let old_label = self.current_try_block_label.replace(label);
let ptr = AstPtr::new(&e).upcast();
let (btail, expr_id) = self.with_labeled_rib(label, HygieneId::ROOT, |this| {
let mut btail = None;
let block = this.collect_block_(e, |id, statements, tail| {
btail = tail;
Expr::Block { id, statements, tail, label: Some(label) }
});
(btail, block)
});
let callee = self
.alloc_expr_desugared_with_ptr(try_from_output.map_or(Expr::Missing, Expr::Path), ptr);
let next_tail = match btail {
Some(tail) => self
.alloc_expr_desugared_with_ptr(Expr::Call { callee, args: Box::new([tail]) }, ptr),
None => {
let unit =
self.alloc_expr_desugared_with_ptr(Expr::Tuple { exprs: Box::new([]) }, ptr);
self.alloc_expr_desugared_with_ptr(
Expr::Call { callee, args: Box::new([unit]) },
ptr,
)
}
};
let Expr::Block { tail, .. } = &mut self.store.exprs[expr_id] else {
unreachable!("block was lowered to non-block");
};
*tail = Some(next_tail);
self.current_try_block_label = old_label;
expr_id
}
/// Desugar `ast::WhileExpr` from: `[opt_ident]: while <cond> <body>` into:
/// ```ignore (pseudo-rust)
/// [opt_ident]: loop {
/// if <cond> {
/// <body>
/// }
/// else {
/// break;
/// }
/// }
/// ```
/// FIXME: Rustc wraps the condition in a construct equivalent to `{ let _t = <cond>; _t }`
/// to preserve drop semantics. We should probably do the same in future.
fn collect_while_loop(&mut self, syntax_ptr: AstPtr<ast::Expr>, e: ast::WhileExpr) -> ExprId {
let label = e.label().map(|label| {
(self.hygiene_id_for(label.syntax().text_range()), self.collect_label(label))
});
let body = self.collect_labelled_block_opt(label, e.loop_body());
// Labels can also be used in the condition expression, like this:
// ```
// fn main() {
// let mut optional = Some(0);
// 'my_label: while let Some(a) = match optional {
// None => break 'my_label,
// Some(val) => Some(val),
// } {
// println!("{}", a);
// optional = None;
// }
// }
// ```
let condition = match label {
Some((label_hygiene, label)) => self.with_labeled_rib(label, label_hygiene, |this| {
this.collect_expr_opt(e.condition())
}),
None => self.collect_expr_opt(e.condition()),
};
let break_expr = self.alloc_expr(Expr::Break { expr: None, label: None }, syntax_ptr);
let if_expr = self.alloc_expr(
Expr::If { condition, then_branch: body, else_branch: Some(break_expr) },
syntax_ptr,
);
self.alloc_expr(Expr::Loop { body: if_expr, label: label.map(|it| it.1) }, syntax_ptr)
}
/// Desugar `ast::ForExpr` from: `[opt_ident]: for <pat> in <head> <body>` into:
/// ```ignore (pseudo-rust)
/// match IntoIterator::into_iter(<head>) {
/// mut iter => {
/// [opt_ident]: loop {
/// match Iterator::next(&mut iter) {
/// None => break,
/// Some(<pat>) => <body>,
/// };
/// }
/// }
/// }
/// ```
fn collect_for_loop(&mut self, syntax_ptr: AstPtr<ast::Expr>, e: ast::ForExpr) -> ExprId {
let into_iter_fn = self.lang_path(LangItem::IntoIterIntoIter);
let iter_next_fn = self.lang_path(LangItem::IteratorNext);
let option_some = self.lang_path(LangItem::OptionSome);
let option_none = self.lang_path(LangItem::OptionNone);
let head = self.collect_expr_opt(e.iterable());
let into_iter_fn_expr =
self.alloc_expr(into_iter_fn.map_or(Expr::Missing, Expr::Path), syntax_ptr);
let iterator = self.alloc_expr(
Expr::Call { callee: into_iter_fn_expr, args: Box::new([head]) },
syntax_ptr,
);
let none_arm = MatchArm {
pat: self.alloc_pat_desugared(option_none.map_or(Pat::Missing, Pat::Path)),
guard: None,
expr: self.alloc_expr(Expr::Break { expr: None, label: None }, syntax_ptr),
};
let some_pat = Pat::TupleStruct {
path: option_some.map(Box::new),
args: Box::new([self.collect_pat_top(e.pat())]),
ellipsis: None,
};
let label = e.label().map(|label| {
(self.hygiene_id_for(label.syntax().text_range()), self.collect_label(label))
});
let some_arm = MatchArm {
pat: self.alloc_pat_desugared(some_pat),
guard: None,
expr: self.with_opt_labeled_rib(label, |this| {
this.collect_expr_opt(e.loop_body().map(|it| it.into()))
}),
};
let iter_name = Name::generate_new_name(self.store.exprs.len());
let iter_expr = self.alloc_expr(Expr::Path(Path::from(iter_name.clone())), syntax_ptr);
let iter_expr_mut = self.alloc_expr(
Expr::Ref { expr: iter_expr, rawness: Rawness::Ref, mutability: Mutability::Mut },
syntax_ptr,
);
let iter_next_fn_expr =
self.alloc_expr(iter_next_fn.map_or(Expr::Missing, Expr::Path), syntax_ptr);
let iter_next_expr = self.alloc_expr(
Expr::Call { callee: iter_next_fn_expr, args: Box::new([iter_expr_mut]) },
syntax_ptr,
);
let loop_inner = self.alloc_expr(
Expr::Match { expr: iter_next_expr, arms: Box::new([none_arm, some_arm]) },
syntax_ptr,
);
let loop_inner = self.alloc_expr(
Expr::Block {
id: None,
statements: Box::default(),
tail: Some(loop_inner),
label: None,
},
syntax_ptr,
);
let loop_outer = self
.alloc_expr(Expr::Loop { body: loop_inner, label: label.map(|it| it.1) }, syntax_ptr);
let iter_binding =
self.alloc_binding(iter_name, BindingAnnotation::Mutable, HygieneId::ROOT);
let iter_pat = self.alloc_pat_desugared(Pat::Bind { id: iter_binding, subpat: None });
self.add_definition_to_binding(iter_binding, iter_pat);
self.alloc_expr(
Expr::Match {
expr: iterator,
arms: Box::new([MatchArm { pat: iter_pat, guard: None, expr: loop_outer }]),
},
syntax_ptr,
)
}
/// Desugar `ast::TryExpr` from: `<expr>?` into:
/// ```ignore (pseudo-rust)
/// match Try::branch(<expr>) {
/// ControlFlow::Continue(val) => val,
/// ControlFlow::Break(residual) =>
/// // If there is an enclosing `try {...}`:
/// break 'catch_target Try::from_residual(residual),
/// // Otherwise:
/// return Try::from_residual(residual),
/// }
/// ```
fn collect_try_operator(&mut self, syntax_ptr: AstPtr<ast::Expr>, e: ast::TryExpr) -> ExprId {
let try_branch = self.lang_path(LangItem::TryTraitBranch);
let cf_continue = self.lang_path(LangItem::ControlFlowContinue);
let cf_break = self.lang_path(LangItem::ControlFlowBreak);
let try_from_residual = self.lang_path(LangItem::TryTraitFromResidual);
let operand = self.collect_expr_opt(e.expr());
let try_branch = self.alloc_expr(try_branch.map_or(Expr::Missing, Expr::Path), syntax_ptr);
let expr = self
.alloc_expr(Expr::Call { callee: try_branch, args: Box::new([operand]) }, syntax_ptr);
let continue_name = Name::generate_new_name(self.store.bindings.len());
let continue_binding = self.alloc_binding(
continue_name.clone(),
BindingAnnotation::Unannotated,
HygieneId::ROOT,
);
let continue_bpat =
self.alloc_pat_desugared(Pat::Bind { id: continue_binding, subpat: None });
self.add_definition_to_binding(continue_binding, continue_bpat);
let continue_arm = MatchArm {
pat: self.alloc_pat_desugared(Pat::TupleStruct {
path: cf_continue.map(Box::new),
args: Box::new([continue_bpat]),
ellipsis: None,
}),
guard: None,
expr: self.alloc_expr(Expr::Path(Path::from(continue_name)), syntax_ptr),
};
let break_name = Name::generate_new_name(self.store.bindings.len());
let break_binding =
self.alloc_binding(break_name.clone(), BindingAnnotation::Unannotated, HygieneId::ROOT);
let break_bpat = self.alloc_pat_desugared(Pat::Bind { id: break_binding, subpat: None });
self.add_definition_to_binding(break_binding, break_bpat);
let break_arm = MatchArm {
pat: self.alloc_pat_desugared(Pat::TupleStruct {
path: cf_break.map(Box::new),
args: Box::new([break_bpat]),
ellipsis: None,
}),
guard: None,
expr: {
let it = self.alloc_expr(Expr::Path(Path::from(break_name)), syntax_ptr);
let callee = self
.alloc_expr(try_from_residual.map_or(Expr::Missing, Expr::Path), syntax_ptr);
let result =
self.alloc_expr(Expr::Call { callee, args: Box::new([it]) }, syntax_ptr);
self.alloc_expr(
match self.current_try_block_label {
Some(label) => Expr::Break { expr: Some(result), label: Some(label) },
None => Expr::Return { expr: Some(result) },
},
syntax_ptr,
)
},
};
let arms = Box::new([continue_arm, break_arm]);
self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
}
fn collect_macro_call<T, U>(
&mut self,
mcall: ast::MacroCall,
syntax_ptr: AstPtr<ast::MacroCall>,
record_diagnostics: bool,
collector: impl FnOnce(&mut Self, Option<T>) -> U,
) -> U
where
T: ast::AstNode,
{
let macro_call_ptr = self.expander.in_file(syntax_ptr);
let module = self.module.local_id;
let block_call = self.def_map.modules[self.module.local_id].scope.macro_invoc(
self.expander.in_file(self.expander.ast_id_map().ast_id_for_ptr(syntax_ptr)),
);
let res = match block_call {
// fast path, macro call is in a block module
Some(call) => Ok(self.expander.enter_expand_id(self.db, call)),
None => {
let resolver = |path: &_| {
self.def_map
.resolve_path(
&self.local_def_map,
self.db,
module,
path,
crate::item_scope::BuiltinShadowMode::Other,
Some(MacroSubNs::Bang),
)
.0
.take_macros()
};
self.expander.enter_expand(
self.db,
mcall,
self.module.krate(),
resolver,
&mut |ptr, call| {
_ = self.source_map.expansions.insert(ptr.map(|(it, _)| it), call);
},
)
}
};
let res = match res {
Ok(res) => res,
Err(UnresolvedMacro { path }) => {
if record_diagnostics {
self.source_map.diagnostics.push(
ExpressionStoreDiagnostics::UnresolvedMacroCall {
node: self.expander.in_file(syntax_ptr),
path,
},
);
}
return collector(self, None);
}
};
if record_diagnostics {
if let Some(err) = res.err {
self.source_map
.diagnostics
.push(ExpressionStoreDiagnostics::MacroError { node: macro_call_ptr, err });
}
}
match res.value {
Some((mark, expansion)) => {
// Keep collecting even with expansion errors so we can provide completions and
// other services in incomplete macro expressions.
if let Some(macro_file) = self.expander.current_file_id().macro_file() {
self.source_map.expansions.insert(macro_call_ptr, macro_file);
}
if record_diagnostics {
// FIXME: Report parse errors here
}
let id = collector(self, expansion.map(|it| it.tree()));
self.expander.exit(mark);
id
}
None => collector(self, None),
}
}
fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
match expr {
Some(expr) => self.collect_expr(expr),
None => self.missing_expr(),
}
}
fn collect_macro_as_stmt(
&mut self,
statements: &mut Vec<Statement>,
mac: ast::MacroExpr,
) -> Option<ExprId> {
let mac_call = mac.macro_call()?;
let syntax_ptr = AstPtr::new(&ast::Expr::from(mac));
let macro_ptr = AstPtr::new(&mac_call);
let expansion = self.collect_macro_call(
mac_call,
macro_ptr,
false,
|this, expansion: Option<ast::MacroStmts>| match expansion {
Some(expansion) => {
expansion.statements().for_each(|stmt| this.collect_stmt(statements, stmt));
expansion.expr().and_then(|expr| match expr {
ast::Expr::MacroExpr(mac) => this.collect_macro_as_stmt(statements, mac),
expr => Some(this.collect_expr(expr)),
})
}
None => None,
},
);
expansion.inspect(|&tail| {
// Make the macro-call point to its expanded expression so we can query
// semantics on syntax pointers to the macro
let src = self.expander.in_file(syntax_ptr);
self.source_map.expr_map.insert(src, tail.into());
})
}
fn collect_stmt(&mut self, statements: &mut Vec<Statement>, s: ast::Stmt) {
match s {
ast::Stmt::LetStmt(stmt) => {
if self.check_cfg(&stmt).is_none() {
return;
}
let pat = self.collect_pat_top(stmt.pat());
let type_ref = stmt.ty().map(|it| self.lower_type_ref_disallow_impl_trait(it));
let initializer = stmt.initializer().map(|e| self.collect_expr(e));
let else_branch = stmt
.let_else()
.and_then(|let_else| let_else.block_expr())
.map(|block| self.collect_block(block));
statements.push(Statement::Let { pat, type_ref, initializer, else_branch });
}
ast::Stmt::ExprStmt(stmt) => {
let expr = stmt.expr();
match &expr {
Some(expr) if self.check_cfg(expr).is_none() => return,
_ => (),
}
let has_semi = stmt.semicolon_token().is_some();
// Note that macro could be expanded to multiple statements
if let Some(ast::Expr::MacroExpr(mac)) = expr {
if let Some(expr) = self.collect_macro_as_stmt(statements, mac) {
statements.push(Statement::Expr { expr, has_semi })
}
} else {
let expr = self.collect_expr_opt(expr);
statements.push(Statement::Expr { expr, has_semi });
}
}
ast::Stmt::Item(ast::Item::MacroDef(macro_)) => {
if self.check_cfg(&macro_).is_none() {
return;
}
let Some(name) = macro_.name() else {
statements.push(Statement::Item(Item::Other));
return;
};
let name = name.as_name();
let macro_id = self.def_map.modules[DefMap::ROOT].scope.get(&name).take_macros();
self.collect_macro_def(statements, macro_id);
}
ast::Stmt::Item(ast::Item::MacroRules(macro_)) => {
if self.check_cfg(&macro_).is_none() {
return;
}
let Some(name) = macro_.name() else {
statements.push(Statement::Item(Item::Other));
return;
};
let name = name.as_name();
let macro_defs_count =
self.current_block_legacy_macro_defs_count.entry(name.clone()).or_insert(0);
let macro_id = self.def_map.modules[DefMap::ROOT]
.scope
.get_legacy_macro(&name)
.and_then(|it| it.get(*macro_defs_count))
.copied();
*macro_defs_count += 1;
self.collect_macro_def(statements, macro_id);
}
ast::Stmt::Item(_item) => statements.push(Statement::Item(Item::Other)),
}
}
fn collect_macro_def(&mut self, statements: &mut Vec<Statement>, macro_id: Option<MacroId>) {
let Some(macro_id) = macro_id else {
never!("def map should have macro definition, but it doesn't");
statements.push(Statement::Item(Item::Other));
return;
};
let macro_id = self.db.macro_def(macro_id);
statements.push(Statement::Item(Item::MacroDef(Box::new(macro_id))));
self.label_ribs.push(LabelRib::new(RibKind::MacroDef(Box::new(macro_id))));
}
fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
self.collect_block_(block, |id, statements, tail| Expr::Block {
id,
statements,
tail,
label: None,
})
}
fn collect_block_(
&mut self,
block: ast::BlockExpr,
mk_block: impl FnOnce(Option<BlockId>, Box<[Statement]>, Option<ExprId>) -> Expr,
) -> ExprId {
let block_has_items = {
let statement_has_item = block.statements().any(|stmt| match stmt {
ast::Stmt::Item(_) => true,
// Macro calls can be both items and expressions. The syntax library always treats
// them as expressions here, so we undo that.
ast::Stmt::ExprStmt(es) => matches!(es.expr(), Some(ast::Expr::MacroExpr(_))),
_ => false,
});
statement_has_item
|| matches!(block.tail_expr(), Some(ast::Expr::MacroExpr(_)))
|| (block.may_carry_attributes() && block.attrs().next().is_some())
};
let block_id = if block_has_items {
let file_local_id = self.expander.ast_id_map().ast_id(&block);
let ast_id = self.expander.in_file(file_local_id);
Some(self.db.intern_block(BlockLoc { ast_id, module: self.module }))
} else {
None
};
let (module, def_map) =
match block_id.map(|block_id| (self.db.block_def_map(block_id), block_id)) {
Some((def_map, block_id)) => {
self.store.block_scopes.push(block_id);
(def_map.module_id(DefMap::ROOT), def_map)
}
None => (self.module, self.def_map.clone()),
};
let prev_def_map = mem::replace(&mut self.def_map, def_map);
let prev_local_module = mem::replace(&mut self.module, module);
let prev_legacy_macros_count = mem::take(&mut self.current_block_legacy_macro_defs_count);
let mut statements = Vec::new();
block.statements().for_each(|s| self.collect_stmt(&mut statements, s));
let tail = block.tail_expr().and_then(|e| match e {
ast::Expr::MacroExpr(mac) => self.collect_macro_as_stmt(&mut statements, mac),
expr => self.maybe_collect_expr(expr),
});
let tail = tail.or_else(|| {
let stmt = statements.pop()?;
if let Statement::Expr { expr, has_semi: false } = stmt {
return Some(expr);
}
statements.push(stmt);
None
});
let syntax_node_ptr = AstPtr::new(&block.into());
let expr_id = self
.alloc_expr(mk_block(block_id, statements.into_boxed_slice(), tail), syntax_node_ptr);
self.def_map = prev_def_map;
self.module = prev_local_module;
self.current_block_legacy_macro_defs_count = prev_legacy_macros_count;
expr_id
}
fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
match expr {
Some(block) => self.collect_block(block),
None => self.missing_expr(),
}
}
fn collect_labelled_block_opt(
&mut self,
label: Option<(HygieneId, LabelId)>,
expr: Option<ast::BlockExpr>,
) -> ExprId {
match label {
Some((hygiene, label)) => {
self.with_labeled_rib(label, hygiene, |this| this.collect_block_opt(expr))
}
None => self.collect_block_opt(expr),
}
}
// region: patterns
fn collect_pat_top(&mut self, pat: Option<ast::Pat>) -> PatId {
match pat {
Some(pat) => self.collect_pat(pat, &mut BindingList::default()),
None => self.missing_pat(),
}
}
fn collect_pat(&mut self, pat: ast::Pat, binding_list: &mut BindingList) -> PatId {
let pattern = match &pat {
ast::Pat::IdentPat(bp) => {
let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
let hygiene = bp
.name()
.map(|name| self.hygiene_id_for(name.syntax().text_range()))
.unwrap_or(HygieneId::ROOT);
let annotation =
BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
let subpat = bp.pat().map(|subpat| self.collect_pat(subpat, binding_list));
let is_simple_ident_pat =
annotation == BindingAnnotation::Unannotated && subpat.is_none();
let (binding, pattern) = if is_simple_ident_pat {
// This could also be a single-segment path pattern. To
// decide that, we need to try resolving the name.
let (resolved, _) = self.def_map.resolve_path(
&self.local_def_map,
self.db,
self.module.local_id,
&name.clone().into(),
BuiltinShadowMode::Other,
None,
);
// Funnily enough, record structs/variants *can* be shadowed
// by pattern bindings (but unit or tuple structs/variants
// can't).
match resolved.take_values() {
Some(ModuleDefId::ConstId(_)) => (None, Pat::Path(name.into())),
Some(ModuleDefId::EnumVariantId(variant))
if {
let loc = variant.lookup(self.db);
let tree = loc.item_tree_id().item_tree(self.db);
tree[loc.id.value].shape != FieldsShape::Record
} =>
{
(None, Pat::Path(name.into()))
}
Some(ModuleDefId::AdtId(AdtId::StructId(s)))
// FIXME: This can cause a cycle if the user is writing invalid code
if self.db.struct_signature(s).shape != FieldsShape::Record =>
{
(None, Pat::Path(name.into()))
}
// shadowing statics is an error as well, so we just ignore that case here
_ => {
let id = binding_list.find(self, name, hygiene, annotation);
(Some(id), Pat::Bind { id, subpat })
}
}
} else {
let id = binding_list.find(self, name, hygiene, annotation);
(Some(id), Pat::Bind { id, subpat })
};
let ptr = AstPtr::new(&pat);
let pat = self.alloc_pat(pattern, ptr);
if let Some(binding_id) = binding {
self.add_definition_to_binding(binding_id, pat);
}
return pat;
}
ast::Pat::TupleStructPat(p) => {
let path = p
.path()
.and_then(|path| self.lower_path(path, &mut |_| TypeRef::Error))
.map(Box::new);
let (args, ellipsis) = self.collect_tuple_pat(
p.fields(),
comma_follows_token(p.l_paren_token()),
binding_list,
);
Pat::TupleStruct { path, args, ellipsis }
}
ast::Pat::RefPat(p) => {
let pat = self.collect_pat_opt(p.pat(), binding_list);
let mutability = Mutability::from_mutable(p.mut_token().is_some());
Pat::Ref { pat, mutability }
}
ast::Pat::PathPat(p) => {
let path = p.path().and_then(|path| self.lower_path(path, &mut |_| TypeRef::Error));
path.map(Pat::Path).unwrap_or(Pat::Missing)
}
ast::Pat::OrPat(p) => 'b: {
let prev_is_used = mem::take(&mut binding_list.is_used);
let prev_reject_new = mem::take(&mut binding_list.reject_new);
let mut pats = Vec::with_capacity(p.pats().count());
let mut it = p.pats();
let Some(first) = it.next() else {
break 'b Pat::Or(Box::new([]));
};
pats.push(self.collect_pat(first, binding_list));
binding_list.reject_new = true;
for rest in it {
for (_, it) in binding_list.is_used.iter_mut() {
*it = false;
}
pats.push(self.collect_pat(rest, binding_list));
for (&id, &is_used) in binding_list.is_used.iter() {
if !is_used {
self.store.bindings[id].problems =
Some(BindingProblems::NotBoundAcrossAll);
}
}
}
binding_list.reject_new = prev_reject_new;
let current_is_used = mem::replace(&mut binding_list.is_used, prev_is_used);
for (id, _) in current_is_used.into_iter() {
binding_list.check_is_used(self, id);
}
if let &[pat] = &*pats {
// Leading pipe without real OR pattern. Leaving an one-item OR pattern may confuse later stages.
return pat;
}
Pat::Or(pats.into())
}
ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat(), binding_list),
ast::Pat::TuplePat(p) => {
let (args, ellipsis) = self.collect_tuple_pat(
p.fields(),
comma_follows_token(p.l_paren_token()),
binding_list,
);
Pat::Tuple { args, ellipsis }
}
ast::Pat::WildcardPat(_) => Pat::Wild,
ast::Pat::RecordPat(p) => {
let path = p
.path()
.and_then(|path| self.lower_path(path, &mut |_| TypeRef::Error))
.map(Box::new);
let record_pat_field_list =
&p.record_pat_field_list().expect("every struct should have a field list");
let args = record_pat_field_list
.fields()
.filter_map(|f| {
self.check_cfg(&f)?;
let ast_pat = f.pat()?;
let pat = self.collect_pat(ast_pat, binding_list);
let name = f.field_name()?.as_name();
let src = self.expander.in_file(AstPtr::new(&f).wrap_right());
self.source_map.pat_field_map_back.insert(pat, src);
Some(RecordFieldPat { name, pat })
})
.collect();
let ellipsis = record_pat_field_list.rest_pat().is_some();
Pat::Record { path, args, ellipsis }
}
ast::Pat::SlicePat(p) => {
let SlicePatComponents { prefix, slice, suffix } = p.components();
// FIXME properly handle `RestPat`
Pat::Slice {
prefix: prefix.into_iter().map(|p| self.collect_pat(p, binding_list)).collect(),
slice: slice.map(|p| self.collect_pat(p, binding_list)),
suffix: suffix.into_iter().map(|p| self.collect_pat(p, binding_list)).collect(),
}
}
ast::Pat::LiteralPat(lit) => 'b: {
let Some((hir_lit, ast_lit)) = pat_literal_to_hir(lit) else {
break 'b Pat::Missing;
};
let expr = Expr::Literal(hir_lit);
let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
let expr_id = self.alloc_expr(expr, expr_ptr);
Pat::Lit(expr_id)
}
ast::Pat::RestPat(_) => {
// `RestPat` requires special handling and should not be mapped
// to a Pat. Here we are using `Pat::Missing` as a fallback for
// when `RestPat` is mapped to `Pat`, which can easily happen
// when the source code being analyzed has a malformed pattern
// which includes `..` in a place where it isn't valid.
Pat::Missing
}
ast::Pat::BoxPat(boxpat) => {
let inner = self.collect_pat_opt(boxpat.pat(), binding_list);
Pat::Box { inner }
}
ast::Pat::ConstBlockPat(const_block_pat) => {
if let Some(block) = const_block_pat.block_expr() {
let expr_id = self.with_label_rib(RibKind::Constant, |this| {
let syntax_ptr = AstPtr::new(&block.clone().into());
this.collect_as_a_binding_owner_bad(
|this| this.collect_block(block),
syntax_ptr,
)
});
Pat::ConstBlock(expr_id)
} else {
Pat::Missing
}
}
ast::Pat::MacroPat(mac) => match mac.macro_call() {
Some(call) => {
let macro_ptr = AstPtr::new(&call);
let src = self.expander.in_file(AstPtr::new(&pat));
let pat =
self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
this.collect_pat_opt(expanded_pat, binding_list)
});
self.source_map.pat_map.insert(src, pat.into());
return pat;
}
None => Pat::Missing,
},
ast::Pat::RangePat(p) => {
let mut range_part_lower = |p: Option<ast::Pat>| -> Option<ExprId> {
p.and_then(|it| {
let ptr = PatPtr::new(&it);
match &it {
ast::Pat::LiteralPat(it) => Some(self.alloc_expr_from_pat(
Expr::Literal(pat_literal_to_hir(it)?.0),
ptr,
)),
ast::Pat::IdentPat(ident) if ident.is_simple_ident() => ident
.name()
.map(|name| name.as_name())
.map(Path::from)
.map(|path| self.alloc_expr_from_pat(Expr::Path(path), ptr)),
ast::Pat::PathPat(p) => p
.path()
.and_then(|path| self.lower_path(path, &mut |_| TypeRef::Error))
.map(|parsed| self.alloc_expr_from_pat(Expr::Path(parsed), ptr)),
// We only need to handle literal, ident (if bare) and path patterns here,
// as any other pattern as a range pattern operand is semantically invalid.
_ => None,
}
})
};
let start = range_part_lower(p.start());
let end = range_part_lower(p.end());
Pat::Range { start, end }
}
};
let ptr = AstPtr::new(&pat);
self.alloc_pat(pattern, ptr)
}
fn collect_pat_opt(&mut self, pat: Option<ast::Pat>, binding_list: &mut BindingList) -> PatId {
match pat {
Some(pat) => self.collect_pat(pat, binding_list),
None => self.missing_pat(),
}
}
fn collect_tuple_pat(
&mut self,
args: AstChildren<ast::Pat>,
has_leading_comma: bool,
binding_list: &mut BindingList,
) -> (Box<[PatId]>, Option<u32>) {
let args: Vec<_> = args.map(|p| self.collect_pat_possibly_rest(p, binding_list)).collect();
// Find the location of the `..`, if there is one. Note that we do not
// consider the possibility of there being multiple `..` here.
let ellipsis = args.iter().position(|p| p.is_right()).map(|it| it as u32);
// We want to skip the `..` pattern here, since we account for it above.
let mut args: Vec<_> = args.into_iter().filter_map(Either::left).collect();
// if there is a leading comma, the user is most likely to type out a leading pattern
// so we insert a missing pattern at the beginning for IDE features
if has_leading_comma {
args.insert(0, self.missing_pat());
}
(args.into_boxed_slice(), ellipsis)
}
// `collect_pat` rejects `ast::Pat::RestPat`, but it should be handled in some cases that
// it is the macro expansion result of an arg sub-pattern in a slice or tuple pattern.
fn collect_pat_possibly_rest(
&mut self,
pat: ast::Pat,
binding_list: &mut BindingList,
) -> Either<PatId, ()> {
match &pat {
ast::Pat::RestPat(_) => Either::Right(()),
ast::Pat::MacroPat(mac) => match mac.macro_call() {
Some(call) => {
let macro_ptr = AstPtr::new(&call);
let src = self.expander.in_file(AstPtr::new(&pat));
let pat =
self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
if let Some(expanded_pat) = expanded_pat {
this.collect_pat_possibly_rest(expanded_pat, binding_list)
} else {
Either::Left(this.missing_pat())
}
});
if let Some(pat) = pat.left() {
self.source_map.pat_map.insert(src, pat.into());
}
pat
}
None => {
let ptr = AstPtr::new(&pat);
Either::Left(self.alloc_pat(Pat::Missing, ptr))
}
},
_ => Either::Left(self.collect_pat(pat, binding_list)),
}
}
// endregion: patterns
/// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
/// not.
fn check_cfg(&mut self, owner: &dyn ast::HasAttrs) -> Option<()> {
let attrs = self.expander.attrs(self.db, self.module.krate(), owner);
match attrs.cfg() {
Some(cfg) => {
let cfg_options = self.module.krate().cfg_options(self.db);
if cfg_options.check(&cfg) != Some(false) {
return Some(());
}
self.source_map.diagnostics.push(ExpressionStoreDiagnostics::InactiveCode {
node: self.expander.in_file(SyntaxNodePtr::new(owner.syntax())),
cfg,
opts: cfg_options.clone(),
});
None
}
None => Some(()),
}
}
fn add_definition_to_binding(&mut self, binding_id: BindingId, pat_id: PatId) {
self.source_map.binding_definitions.entry(binding_id).or_default().push(pat_id);
}
// region: labels
fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
let label = Label {
name: ast_label
.lifetime()
.as_ref()
.map_or_else(Name::missing, |lt| Name::new_lifetime(&lt.text())),
};
self.alloc_label(label, AstPtr::new(&ast_label))
}
fn resolve_label(
&self,
lifetime: Option<ast::Lifetime>,
) -> Result<Option<LabelId>, ExpressionStoreDiagnostics> {
let Some(lifetime) = lifetime else { return Ok(None) };
let mut hygiene_id =
self.expander.hygiene_for_range(self.db, lifetime.syntax().text_range());
let mut hygiene_info = if hygiene_id.is_root() {
None
} else {
hygiene_id.lookup().outer_expn(self.db).map(|expansion| {
let expansion = self.db.lookup_intern_macro_call(expansion.into());
(hygiene_id.lookup().parent(self.db), expansion.def)
})
};
let name = Name::new_lifetime(&lifetime.text());
for (rib_idx, rib) in self.label_ribs.iter().enumerate().rev() {
match &rib.kind {
RibKind::Normal(label_name, id, label_hygiene) => {
if *label_name == name && *label_hygiene == hygiene_id {
return if self.is_label_valid_from_rib(rib_idx) {
Ok(Some(*id))
} else {
Err(ExpressionStoreDiagnostics::UnreachableLabel {
name,
node: self.expander.in_file(AstPtr::new(&lifetime)),
})
};
}
}
RibKind::MacroDef(macro_id) => {
if let Some((parent_ctx, label_macro_id)) = hygiene_info {
if label_macro_id == **macro_id {
// A macro is allowed to refer to labels from before its declaration.
// Therefore, if we got to the rib of its declaration, give up its hygiene
// and use its parent expansion.
hygiene_id =
HygieneId::new(parent_ctx.opaque_and_semitransparent(self.db));
hygiene_info = parent_ctx.outer_expn(self.db).map(|expansion| {
let expansion = self.db.lookup_intern_macro_call(expansion.into());
(parent_ctx.parent(self.db), expansion.def)
});
}
}
}
_ => {}
}
}
Err(ExpressionStoreDiagnostics::UndeclaredLabel {
name,
node: self.expander.in_file(AstPtr::new(&lifetime)),
})
}
fn is_label_valid_from_rib(&self, rib_index: usize) -> bool {
!self.label_ribs[rib_index + 1..].iter().any(|rib| rib.kind.is_label_barrier())
}
fn pop_label_rib(&mut self) {
// We need to pop all macro defs, plus one rib.
while let Some(LabelRib { kind: RibKind::MacroDef(_) }) = self.label_ribs.pop() {
// Do nothing.
}
}
fn with_label_rib<T>(&mut self, kind: RibKind, f: impl FnOnce(&mut Self) -> T) -> T {
self.label_ribs.push(LabelRib::new(kind));
let res = f(self);
self.pop_label_rib();
res
}
fn with_labeled_rib<T>(
&mut self,
label: LabelId,
hygiene: HygieneId,
f: impl FnOnce(&mut Self) -> T,
) -> T {
self.label_ribs.push(LabelRib::new(RibKind::Normal(
self.store.labels[label].name.clone(),
label,
hygiene,
)));
let res = f(self);
self.pop_label_rib();
res
}
fn with_opt_labeled_rib<T>(
&mut self,
label: Option<(HygieneId, LabelId)>,
f: impl FnOnce(&mut Self) -> T,
) -> T {
match label {
None => f(self),
Some((hygiene, label)) => self.with_labeled_rib(label, hygiene, f),
}
}
// endregion: labels
// region: format
fn expand_macros_to_string(&mut self, expr: ast::Expr) -> Option<(ast::String, bool)> {
let m = match expr {
ast::Expr::MacroExpr(m) => m,
ast::Expr::Literal(l) => {
return match l.kind() {
ast::LiteralKind::String(s) => Some((s, true)),
_ => None,
};
}
_ => return None,
};
let e = m.macro_call()?;
let macro_ptr = AstPtr::new(&e);
let (exp, _) = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
expansion.and_then(|it| this.expand_macros_to_string(it))
})?;
Some((exp, false))
}
fn collect_format_args(
&mut self,
f: ast::FormatArgsExpr,
syntax_ptr: AstPtr<ast::Expr>,
) -> ExprId {
let mut args = FormatArgumentsCollector::default();
f.args().for_each(|arg| {
args.add(FormatArgument {
kind: match arg.name() {
Some(name) => FormatArgumentKind::Named(name.as_name()),
None => FormatArgumentKind::Normal,
},
expr: self.collect_expr_opt(arg.expr()),
});
});
let template = f.template();
let fmt_snippet = template.as_ref().and_then(|it| match it {
ast::Expr::Literal(literal) => match literal.kind() {
ast::LiteralKind::String(s) => Some(s.text().to_owned()),
_ => None,
},
_ => None,
});
let mut mappings = vec![];
let (fmt, hygiene) = match template.and_then(|template| {
self.expand_macros_to_string(template.clone()).map(|it| (it, template))
}) {
Some(((s, is_direct_literal), template)) => {
let call_ctx = self.expander.call_syntax_ctx();
let hygiene = self.hygiene_id_for(s.syntax().text_range());
let fmt = format_args::parse(
&s,
fmt_snippet,
args,
is_direct_literal,
|name, range| {
let expr_id = self.alloc_expr_desugared(Expr::Path(Path::from(name)));
if let Some(range) = range {
self.source_map
.template_map
.get_or_insert_with(Default::default)
.implicit_capture_to_source
.insert(
expr_id,
self.expander.in_file((AstPtr::new(&template), range)),
);
}
if !hygiene.is_root() {
self.store.ident_hygiene.insert(expr_id.into(), hygiene);
}
expr_id
},
|name, span| {
if let Some(span) = span {
mappings.push((span, name))
}
},
call_ctx,
);
(fmt, hygiene)
}
None => (
FormatArgs {
template: Default::default(),
arguments: args.finish(),
orphans: Default::default(),
},
HygieneId::ROOT,
),
};
// Create a list of all _unique_ (argument, format trait) combinations.
// E.g. "{0} {0:x} {0} {1}" -> [(0, Display), (0, LowerHex), (1, Display)]
let mut argmap = FxIndexSet::default();
for piece in fmt.template.iter() {
let FormatArgsPiece::Placeholder(placeholder) = piece else { continue };
if let Ok(index) = placeholder.argument.index {
argmap.insert((index, ArgumentType::Format(placeholder.format_trait)));
}
}
let lit_pieces = fmt
.template
.iter()
.enumerate()
.filter_map(|(i, piece)| {
match piece {
FormatArgsPiece::Literal(s) => {
Some(self.alloc_expr_desugared(Expr::Literal(Literal::String(s.clone()))))
}
&FormatArgsPiece::Placeholder(_) => {
// Inject empty string before placeholders when not already preceded by a literal piece.
if i == 0 || matches!(fmt.template[i - 1], FormatArgsPiece::Placeholder(_))
{
Some(self.alloc_expr_desugared(Expr::Literal(Literal::String(
Symbol::empty(),
))))
} else {
None
}
}
}
})
.collect();
let lit_pieces =
self.alloc_expr_desugared(Expr::Array(Array::ElementList { elements: lit_pieces }));
let lit_pieces = self.alloc_expr_desugared(Expr::Ref {
expr: lit_pieces,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
});
let format_options = {
// Generate:
// &[format_spec_0, format_spec_1, format_spec_2]
let elements = fmt
.template
.iter()
.filter_map(|piece| {
let FormatArgsPiece::Placeholder(placeholder) = piece else { return None };
Some(self.make_format_spec(placeholder, &mut argmap))
})
.collect();
let array = self.alloc_expr_desugared(Expr::Array(Array::ElementList { elements }));
self.alloc_expr_desugared(Expr::Ref {
expr: array,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
})
};
let arguments = &*fmt.arguments.arguments;
let args = if arguments.is_empty() {
let expr = self
.alloc_expr_desugared(Expr::Array(Array::ElementList { elements: Box::default() }));
self.alloc_expr_desugared(Expr::Ref {
expr,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
})
} else {
// Generate:
// &match (&arg0, &arg1, &…) {
// args => [
// <core::fmt::Argument>::new_display(args.0),
// <core::fmt::Argument>::new_lower_hex(args.1),
// <core::fmt::Argument>::new_debug(args.0),
// …
// ]
// }
let args = argmap
.iter()
.map(|&(arg_index, ty)| {
let arg = self.alloc_expr_desugared(Expr::Ref {
expr: arguments[arg_index].expr,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
});
self.make_argument(arg, ty)
})
.collect();
let array =
self.alloc_expr_desugared(Expr::Array(Array::ElementList { elements: args }));
self.alloc_expr_desugared(Expr::Ref {
expr: array,
rawness: Rawness::Ref,
mutability: Mutability::Shared,
})
};
// Generate:
// <core::fmt::Arguments>::new_v1_formatted(
// lit_pieces,
// args,
// format_options,
// unsafe { ::core::fmt::UnsafeArg::new() }
// )
let new_v1_formatted = LangItem::FormatArguments.ty_rel_path(
self.db,
self.module.krate(),
Name::new_symbol_root(sym::new_v1_formatted),
);
let unsafe_arg_new = LangItem::FormatUnsafeArg.ty_rel_path(
self.db,
self.module.krate(),
Name::new_symbol_root(sym::new),
);
let new_v1_formatted =
self.alloc_expr_desugared(new_v1_formatted.map_or(Expr::Missing, Expr::Path));
let unsafe_arg_new =
self.alloc_expr_desugared(unsafe_arg_new.map_or(Expr::Missing, Expr::Path));
let unsafe_arg_new =
self.alloc_expr_desugared(Expr::Call { callee: unsafe_arg_new, args: Box::default() });
let mut unsafe_arg_new = self.alloc_expr_desugared(Expr::Unsafe {
id: None,
statements: Box::new([]),
tail: Some(unsafe_arg_new),
});
if !fmt.orphans.is_empty() {
unsafe_arg_new = self.alloc_expr_desugared(Expr::Block {
id: None,
// We collect the unused expressions here so that we still infer them instead of
// dropping them out of the expression tree. We cannot store them in the `Unsafe`
// block because then unsafe blocks within them will get a false "unused unsafe"
// diagnostic (rustc has a notion of builtin unsafe blocks, but we don't).
statements: fmt
.orphans
.into_iter()
.map(|expr| Statement::Expr { expr, has_semi: true })
.collect(),
tail: Some(unsafe_arg_new),
label: None,
});
}
let idx = self.alloc_expr(
Expr::Call {
callee: new_v1_formatted,
args: Box::new([lit_pieces, args, format_options, unsafe_arg_new]),
},
syntax_ptr,
);
self.source_map
.template_map
.get_or_insert_with(Default::default)
.format_args_to_captures
.insert(idx, (hygiene, mappings));
idx
}
/// Generate a hir expression for a format_args placeholder specification.
///
/// Generates
///
/// ```text
/// <core::fmt::rt::Placeholder::new(
/// …usize, // position
/// '…', // fill
/// <core::fmt::rt::Alignment>::…, // alignment
/// …u32, // flags
/// <core::fmt::rt::Count::…>, // width
/// <core::fmt::rt::Count::…>, // precision
/// )
/// ```
fn make_format_spec(
&mut self,
placeholder: &FormatPlaceholder,
argmap: &mut FxIndexSet<(usize, ArgumentType)>,
) -> ExprId {
let position = match placeholder.argument.index {
Ok(arg_index) => {
let (i, _) =
argmap.insert_full((arg_index, ArgumentType::Format(placeholder.format_trait)));
self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
i as u128,
Some(BuiltinUint::Usize),
)))
}
Err(_) => self.missing_expr(),
};
let &FormatOptions {
ref width,
ref precision,
alignment,
fill,
sign,
alternate,
zero_pad,
debug_hex,
} = &placeholder.format_options;
let precision_expr = self.make_count(precision, argmap);
let width_expr = self.make_count(width, argmap);
if self.module.krate().workspace_data(self.db).is_atleast_187() {
// These need to match the constants in library/core/src/fmt/rt.rs.
let align = match alignment {
Some(FormatAlignment::Left) => 0,
Some(FormatAlignment::Right) => 1,
Some(FormatAlignment::Center) => 2,
None => 3,
};
// This needs to match `Flag` in library/core/src/fmt/rt.rs.
let flags = fill.unwrap_or(' ') as u32
| ((sign == Some(FormatSign::Plus)) as u32) << 21
| ((sign == Some(FormatSign::Minus)) as u32) << 22
| (alternate as u32) << 23
| (zero_pad as u32) << 24
| ((debug_hex == Some(FormatDebugHex::Lower)) as u32) << 25
| ((debug_hex == Some(FormatDebugHex::Upper)) as u32) << 26
| (width.is_some() as u32) << 27
| (precision.is_some() as u32) << 28
| align << 29
| 1 << 31; // Highest bit always set.
let flags = self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
flags as u128,
Some(BuiltinUint::U32),
)));
let position =
RecordLitField { name: Name::new_symbol_root(sym::position), expr: position };
let flags = RecordLitField { name: Name::new_symbol_root(sym::flags), expr: flags };
let precision = RecordLitField {
name: Name::new_symbol_root(sym::precision),
expr: precision_expr,
};
let width =
RecordLitField { name: Name::new_symbol_root(sym::width), expr: width_expr };
self.alloc_expr_desugared(Expr::RecordLit {
path: LangItem::FormatPlaceholder.path(self.db, self.module.krate()).map(Box::new),
fields: Box::new([position, flags, precision, width]),
spread: None,
})
} else {
let format_placeholder_new = {
let format_placeholder_new = LangItem::FormatPlaceholder.ty_rel_path(
self.db,
self.module.krate(),
Name::new_symbol_root(sym::new),
);
match format_placeholder_new {
Some(path) => self.alloc_expr_desugared(Expr::Path(path)),
None => self.missing_expr(),
}
};
// This needs to match `Flag` in library/core/src/fmt/rt.rs.
let flags: u32 = ((sign == Some(FormatSign::Plus)) as u32)
| (((sign == Some(FormatSign::Minus)) as u32) << 1)
| ((alternate as u32) << 2)
| ((zero_pad as u32) << 3)
| (((debug_hex == Some(FormatDebugHex::Lower)) as u32) << 4)
| (((debug_hex == Some(FormatDebugHex::Upper)) as u32) << 5);
let flags = self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
flags as u128,
Some(BuiltinUint::U32),
)));
let fill = self.alloc_expr_desugared(Expr::Literal(Literal::Char(fill.unwrap_or(' '))));
let align = {
let align = LangItem::FormatAlignment.ty_rel_path(
self.db,
self.module.krate(),
match alignment {
Some(FormatAlignment::Left) => Name::new_symbol_root(sym::Left),
Some(FormatAlignment::Right) => Name::new_symbol_root(sym::Right),
Some(FormatAlignment::Center) => Name::new_symbol_root(sym::Center),
None => Name::new_symbol_root(sym::Unknown),
},
);
match align {
Some(path) => self.alloc_expr_desugared(Expr::Path(path)),
None => self.missing_expr(),
}
};
self.alloc_expr_desugared(Expr::Call {
callee: format_placeholder_new,
args: Box::new([position, fill, align, flags, precision_expr, width_expr]),
})
}
}
/// Generate a hir expression for a format_args Count.
///
/// Generates:
///
/// ```text
/// <core::fmt::rt::Count>::Is(…)
/// ```
///
/// or
///
/// ```text
/// <core::fmt::rt::Count>::Param(…)
/// ```
///
/// or
///
/// ```text
/// <core::fmt::rt::Count>::Implied
/// ```
fn make_count(
&mut self,
count: &Option<FormatCount>,
argmap: &mut FxIndexSet<(usize, ArgumentType)>,
) -> ExprId {
match count {
Some(FormatCount::Literal(n)) => {
let args = self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
*n as u128,
// FIXME: Change this to Some(BuiltinUint::U16) once we drop support for toolchains < 1.88
None,
)));
let count_is = match LangItem::FormatCount.ty_rel_path(
self.db,
self.module.krate(),
Name::new_symbol_root(sym::Is),
) {
Some(count_is) => self.alloc_expr_desugared(Expr::Path(count_is)),
None => self.missing_expr(),
};
self.alloc_expr_desugared(Expr::Call { callee: count_is, args: Box::new([args]) })
}
Some(FormatCount::Argument(arg)) => {
if let Ok(arg_index) = arg.index {
let (i, _) = argmap.insert_full((arg_index, ArgumentType::Usize));
let args = self.alloc_expr_desugared(Expr::Literal(Literal::Uint(
i as u128,
Some(BuiltinUint::Usize),
)));
let count_param = match LangItem::FormatCount.ty_rel_path(
self.db,
self.module.krate(),
Name::new_symbol_root(sym::Param),
) {
Some(count_param) => self.alloc_expr_desugared(Expr::Path(count_param)),
None => self.missing_expr(),
};
self.alloc_expr_desugared(Expr::Call {
callee: count_param,
args: Box::new([args]),
})
} else {
// FIXME: This drops arg causing it to potentially not be resolved/type checked
// when typing?
self.missing_expr()
}
}
None => match LangItem::FormatCount.ty_rel_path(
self.db,
self.module.krate(),
Name::new_symbol_root(sym::Implied),
) {
Some(count_param) => self.alloc_expr_desugared(Expr::Path(count_param)),
None => self.missing_expr(),
},
}
}
/// Generate a hir expression representing an argument to a format_args invocation.
///
/// Generates:
///
/// ```text
/// <core::fmt::Argument>::new_…(arg)
/// ```
fn make_argument(&mut self, arg: ExprId, ty: ArgumentType) -> ExprId {
use ArgumentType::*;
use FormatTrait::*;
let new_fn = match LangItem::FormatArgument.ty_rel_path(
self.db,
self.module.krate(),
Name::new_symbol_root(match ty {
Format(Display) => sym::new_display,
Format(Debug) => sym::new_debug,
Format(LowerExp) => sym::new_lower_exp,
Format(UpperExp) => sym::new_upper_exp,
Format(Octal) => sym::new_octal,
Format(Pointer) => sym::new_pointer,
Format(Binary) => sym::new_binary,
Format(LowerHex) => sym::new_lower_hex,
Format(UpperHex) => sym::new_upper_hex,
Usize => sym::from_usize,
}),
) {
Some(new_fn) => self.alloc_expr_desugared(Expr::Path(new_fn)),
None => self.missing_expr(),
};
self.alloc_expr_desugared(Expr::Call { callee: new_fn, args: Box::new([arg]) })
}
// endregion: format
fn lang_path(&self, lang: LangItem) -> Option<Path> {
lang.path(self.db, self.module.krate())
}
}
fn pat_literal_to_hir(lit: &ast::LiteralPat) -> Option<(Literal, ast::Literal)> {
let ast_lit = lit.literal()?;
let mut hir_lit: Literal = ast_lit.kind().into();
if lit.minus_token().is_some() {
hir_lit = hir_lit.negate()?;
}
Some((hir_lit, ast_lit))
}
impl ExprCollector<'_> {
fn alloc_expr(&mut self, expr: Expr, ptr: ExprPtr) -> ExprId {
let src = self.expander.in_file(ptr);
let id = self.store.exprs.alloc(expr);
self.source_map.expr_map_back.insert(id, src.map(AstPtr::wrap_left));
self.source_map.expr_map.insert(src, id.into());
id
}
// FIXME: desugared exprs don't have ptr, that's wrong and should be fixed.
// Migrate to alloc_expr_desugared_with_ptr and then rename back
fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
self.store.exprs.alloc(expr)
}
fn alloc_expr_desugared_with_ptr(&mut self, expr: Expr, ptr: ExprPtr) -> ExprId {
let src = self.expander.in_file(ptr);
let id = self.store.exprs.alloc(expr);
self.source_map.expr_map_back.insert(id, src.map(AstPtr::wrap_left));
// We intentionally don't fill this as it could overwrite a non-desugared entry
// self.source_map.expr_map.insert(src, id);
id
}
fn missing_expr(&mut self) -> ExprId {
self.alloc_expr_desugared(Expr::Missing)
}
fn alloc_binding(
&mut self,
name: Name,
mode: BindingAnnotation,
hygiene: HygieneId,
) -> BindingId {
let binding = self.store.bindings.alloc(Binding { name, mode, problems: None, hygiene });
if let Some(owner) = self.current_binding_owner {
self.store.binding_owners.insert(binding, owner);
}
binding
}
fn alloc_pat_from_expr(&mut self, pat: Pat, ptr: ExprPtr) -> PatId {
let src = self.expander.in_file(ptr);
let id = self.store.pats.alloc(pat);
self.source_map.expr_map.insert(src, id.into());
self.source_map.pat_map_back.insert(id, src.map(AstPtr::wrap_left));
id
}
fn alloc_expr_from_pat(&mut self, expr: Expr, ptr: PatPtr) -> ExprId {
let src = self.expander.in_file(ptr);
let id = self.store.exprs.alloc(expr);
self.source_map.pat_map.insert(src, id.into());
self.source_map.expr_map_back.insert(id, src.map(AstPtr::wrap_right));
id
}
fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
let src = self.expander.in_file(ptr);
let id = self.store.pats.alloc(pat);
self.source_map.pat_map_back.insert(id, src.map(AstPtr::wrap_right));
self.source_map.pat_map.insert(src, id.into());
id
}
// FIXME: desugared pats don't have ptr, that's wrong and should be fixed somehow.
fn alloc_pat_desugared(&mut self, pat: Pat) -> PatId {
self.store.pats.alloc(pat)
}
fn missing_pat(&mut self) -> PatId {
self.store.pats.alloc(Pat::Missing)
}
fn alloc_label(&mut self, label: Label, ptr: LabelPtr) -> LabelId {
let src = self.expander.in_file(ptr);
let id = self.store.labels.alloc(label);
self.source_map.label_map_back.insert(id, src);
self.source_map.label_map.insert(src, id);
id
}
// FIXME: desugared labels don't have ptr, that's wrong and should be fixed somehow.
fn alloc_label_desugared(&mut self, label: Label) -> LabelId {
self.store.labels.alloc(label)
}
fn is_lowering_awaitable_block(&self) -> &Awaitable {
self.awaitable_context.as_ref().unwrap_or(&Awaitable::No("unknown"))
}
fn with_awaitable_block<T>(
&mut self,
awaitable: Awaitable,
f: impl FnOnce(&mut Self) -> T,
) -> T {
let orig = self.awaitable_context.replace(awaitable);
let res = f(self);
self.awaitable_context = orig;
res
}
fn hygiene_id_for(&self, range: TextRange) -> HygieneId {
self.expander.hygiene_for_range(self.db, range)
}
}
fn comma_follows_token(t: Option<syntax::SyntaxToken>) -> bool {
(|| syntax::algo::skip_trivia_token(t?.next_token()?, syntax::Direction::Next))()
.is_some_and(|it| it.kind() == syntax::T![,])
}
#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
enum ArgumentType {
Format(FormatTrait),
Usize,
}
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