2021-01-25 14:12:53 +02:00

782 lines
30 KiB
Rust

//! AST -> `ItemTree` lowering code.
use std::{collections::hash_map::Entry, mem, sync::Arc};
use hir_expand::{ast_id_map::AstIdMap, hygiene::Hygiene, name::known, HirFileId};
use smallvec::SmallVec;
use syntax::{
ast::{self, ModuleItemOwner},
SyntaxNode, WalkEvent,
};
use crate::{
generics::{GenericParams, TypeParamData, TypeParamProvenance},
type_ref::LifetimeRef,
};
use super::*;
fn id<N: ItemTreeNode>(index: Idx<N>) -> FileItemTreeId<N> {
FileItemTreeId { index, _p: PhantomData }
}
struct ModItems(SmallVec<[ModItem; 1]>);
impl<T> From<T> for ModItems
where
T: Into<ModItem>,
{
fn from(t: T) -> Self {
ModItems(SmallVec::from_buf([t.into(); 1]))
}
}
pub(super) struct Ctx {
tree: ItemTree,
hygiene: Hygiene,
file: HirFileId,
source_ast_id_map: Arc<AstIdMap>,
body_ctx: crate::body::LowerCtx,
forced_visibility: Option<RawVisibilityId>,
}
impl Ctx {
pub(super) fn new(db: &dyn DefDatabase, hygiene: Hygiene, file: HirFileId) -> Self {
Self {
tree: ItemTree::default(),
hygiene,
file,
source_ast_id_map: db.ast_id_map(file),
body_ctx: crate::body::LowerCtx::new(db, file),
forced_visibility: None,
}
}
pub(super) fn lower_module_items(mut self, item_owner: &dyn ModuleItemOwner) -> ItemTree {
self.tree.top_level = item_owner
.items()
.flat_map(|item| self.lower_mod_item(&item, false))
.flat_map(|items| items.0)
.collect();
self.tree
}
pub(super) fn lower_inner_items(mut self, within: &SyntaxNode) -> ItemTree {
self.collect_inner_items(within);
self.tree
}
fn data(&mut self) -> &mut ItemTreeData {
self.tree.data_mut()
}
fn lower_mod_item(&mut self, item: &ast::Item, inner: bool) -> Option<ModItems> {
// Collect inner items for 1-to-1-lowered items.
match item {
ast::Item::Struct(_)
| ast::Item::Union(_)
| ast::Item::Enum(_)
| ast::Item::Fn(_)
| ast::Item::TypeAlias(_)
| ast::Item::Const(_)
| ast::Item::Static(_) => {
// Skip this if we're already collecting inner items. We'll descend into all nodes
// already.
if !inner {
self.collect_inner_items(item.syntax());
}
}
// These are handled in their respective `lower_X` method (since we can't just blindly
// walk them).
ast::Item::Trait(_) | ast::Item::Impl(_) | ast::Item::ExternBlock(_) => {}
// These don't have inner items.
ast::Item::Module(_)
| ast::Item::ExternCrate(_)
| ast::Item::Use(_)
| ast::Item::MacroCall(_)
| ast::Item::MacroRules(_)
| ast::Item::MacroDef(_) => {}
};
let attrs = RawAttrs::new(item, &self.hygiene);
let items = match item {
ast::Item::Struct(ast) => self.lower_struct(ast).map(Into::into),
ast::Item::Union(ast) => self.lower_union(ast).map(Into::into),
ast::Item::Enum(ast) => self.lower_enum(ast).map(Into::into),
ast::Item::Fn(ast) => self.lower_function(ast).map(Into::into),
ast::Item::TypeAlias(ast) => self.lower_type_alias(ast).map(Into::into),
ast::Item::Static(ast) => self.lower_static(ast).map(Into::into),
ast::Item::Const(ast) => Some(self.lower_const(ast).into()),
ast::Item::Module(ast) => self.lower_module(ast).map(Into::into),
ast::Item::Trait(ast) => self.lower_trait(ast).map(Into::into),
ast::Item::Impl(ast) => self.lower_impl(ast).map(Into::into),
ast::Item::Use(ast) => Some(ModItems(
self.lower_use(ast).into_iter().map(Into::into).collect::<SmallVec<_>>(),
)),
ast::Item::ExternCrate(ast) => self.lower_extern_crate(ast).map(Into::into),
ast::Item::MacroCall(ast) => self.lower_macro_call(ast).map(Into::into),
ast::Item::MacroRules(ast) => self.lower_macro_rules(ast).map(Into::into),
ast::Item::MacroDef(ast) => self.lower_macro_def(ast).map(Into::into),
ast::Item::ExternBlock(ast) => {
Some(ModItems(self.lower_extern_block(ast).into_iter().collect::<SmallVec<_>>()))
}
};
if !attrs.is_empty() {
for item in items.iter().flat_map(|items| &items.0) {
self.add_attrs((*item).into(), attrs.clone());
}
}
items
}
fn add_attrs(&mut self, item: AttrOwner, attrs: RawAttrs) {
match self.tree.attrs.entry(item) {
Entry::Occupied(mut entry) => {
*entry.get_mut() = entry.get().merge(attrs);
}
Entry::Vacant(entry) => {
entry.insert(attrs);
}
}
}
fn collect_inner_items(&mut self, container: &SyntaxNode) {
let forced_vis = self.forced_visibility.take();
let mut block_stack = Vec::new();
for event in container.preorder().skip(1) {
match event {
WalkEvent::Enter(node) => {
match_ast! {
match node {
ast::BlockExpr(block) => {
block_stack.push(self.source_ast_id_map.ast_id(&block));
},
ast::Item(item) => {
let mod_items = self.lower_mod_item(&item, true);
let current_block = block_stack.last();
if let (Some(mod_items), Some(block)) = (mod_items, current_block) {
if !mod_items.0.is_empty() {
self.data().inner_items.entry(*block).or_default().extend(mod_items.0.iter().copied());
}
}
},
_ => {}
}
}
}
WalkEvent::Leave(node) => {
if ast::BlockExpr::cast(node).is_some() {
block_stack.pop();
}
}
}
}
self.forced_visibility = forced_vis;
}
fn lower_assoc_item(&mut self, item: &ast::AssocItem) -> Option<AssocItem> {
match item {
ast::AssocItem::Fn(ast) => self.lower_function(ast).map(Into::into),
ast::AssocItem::TypeAlias(ast) => self.lower_type_alias(ast).map(Into::into),
ast::AssocItem::Const(ast) => Some(self.lower_const(ast).into()),
ast::AssocItem::MacroCall(ast) => self.lower_macro_call(ast).map(Into::into),
}
}
fn lower_struct(&mut self, strukt: &ast::Struct) -> Option<FileItemTreeId<Struct>> {
let visibility = self.lower_visibility(strukt);
let name = strukt.name()?.as_name();
let generic_params = self.lower_generic_params(GenericsOwner::Struct, strukt);
let fields = self.lower_fields(&strukt.kind());
let ast_id = self.source_ast_id_map.ast_id(strukt);
let kind = match strukt.kind() {
ast::StructKind::Record(_) => StructDefKind::Record,
ast::StructKind::Tuple(_) => StructDefKind::Tuple,
ast::StructKind::Unit => StructDefKind::Unit,
};
let res = Struct { name, visibility, generic_params, fields, ast_id, kind };
Some(id(self.data().structs.alloc(res)))
}
fn lower_fields(&mut self, strukt_kind: &ast::StructKind) -> Fields {
match strukt_kind {
ast::StructKind::Record(it) => {
let range = self.lower_record_fields(it);
Fields::Record(range)
}
ast::StructKind::Tuple(it) => {
let range = self.lower_tuple_fields(it);
Fields::Tuple(range)
}
ast::StructKind::Unit => Fields::Unit,
}
}
fn lower_record_fields(&mut self, fields: &ast::RecordFieldList) -> IdRange<Field> {
let start = self.next_field_idx();
for field in fields.fields() {
if let Some(data) = self.lower_record_field(&field) {
let idx = self.data().fields.alloc(data);
self.add_attrs(idx.into(), RawAttrs::new(&field, &self.hygiene));
}
}
let end = self.next_field_idx();
IdRange::new(start..end)
}
fn lower_record_field(&mut self, field: &ast::RecordField) -> Option<Field> {
let name = field.name()?.as_name();
let visibility = self.lower_visibility(field);
let type_ref = self.lower_type_ref_opt(field.ty());
let res = Field { name, type_ref, visibility };
Some(res)
}
fn lower_tuple_fields(&mut self, fields: &ast::TupleFieldList) -> IdRange<Field> {
let start = self.next_field_idx();
for (i, field) in fields.fields().enumerate() {
let data = self.lower_tuple_field(i, &field);
let idx = self.data().fields.alloc(data);
self.add_attrs(idx.into(), RawAttrs::new(&field, &self.hygiene));
}
let end = self.next_field_idx();
IdRange::new(start..end)
}
fn lower_tuple_field(&mut self, idx: usize, field: &ast::TupleField) -> Field {
let name = Name::new_tuple_field(idx);
let visibility = self.lower_visibility(field);
let type_ref = self.lower_type_ref_opt(field.ty());
let res = Field { name, type_ref, visibility };
res
}
fn lower_union(&mut self, union: &ast::Union) -> Option<FileItemTreeId<Union>> {
let visibility = self.lower_visibility(union);
let name = union.name()?.as_name();
let generic_params = self.lower_generic_params(GenericsOwner::Union, union);
let fields = match union.record_field_list() {
Some(record_field_list) => self.lower_fields(&StructKind::Record(record_field_list)),
None => Fields::Record(IdRange::new(self.next_field_idx()..self.next_field_idx())),
};
let ast_id = self.source_ast_id_map.ast_id(union);
let res = Union { name, visibility, generic_params, fields, ast_id };
Some(id(self.data().unions.alloc(res)))
}
fn lower_enum(&mut self, enum_: &ast::Enum) -> Option<FileItemTreeId<Enum>> {
let visibility = self.lower_visibility(enum_);
let name = enum_.name()?.as_name();
let generic_params = self.lower_generic_params(GenericsOwner::Enum, enum_);
let variants = match &enum_.variant_list() {
Some(variant_list) => self.lower_variants(variant_list),
None => IdRange::new(self.next_variant_idx()..self.next_variant_idx()),
};
let ast_id = self.source_ast_id_map.ast_id(enum_);
let res = Enum { name, visibility, generic_params, variants, ast_id };
Some(id(self.data().enums.alloc(res)))
}
fn lower_variants(&mut self, variants: &ast::VariantList) -> IdRange<Variant> {
let start = self.next_variant_idx();
for variant in variants.variants() {
if let Some(data) = self.lower_variant(&variant) {
let idx = self.data().variants.alloc(data);
self.add_attrs(idx.into(), RawAttrs::new(&variant, &self.hygiene));
}
}
let end = self.next_variant_idx();
IdRange::new(start..end)
}
fn lower_variant(&mut self, variant: &ast::Variant) -> Option<Variant> {
let name = variant.name()?.as_name();
let fields = self.lower_fields(&variant.kind());
let res = Variant { name, fields };
Some(res)
}
fn lower_function(&mut self, func: &ast::Fn) -> Option<FileItemTreeId<Function>> {
let visibility = self.lower_visibility(func);
let name = func.name()?.as_name();
let mut params = Vec::new();
let mut has_self_param = false;
if let Some(param_list) = func.param_list() {
if let Some(self_param) = param_list.self_param() {
let self_type = match self_param.ty() {
Some(type_ref) => TypeRef::from_ast(&self.body_ctx, type_ref),
None => {
let self_type = TypeRef::Path(name![Self].into());
match self_param.kind() {
ast::SelfParamKind::Owned => self_type,
ast::SelfParamKind::Ref => TypeRef::Reference(
Box::new(self_type),
self_param.lifetime().as_ref().map(LifetimeRef::new),
Mutability::Shared,
),
ast::SelfParamKind::MutRef => TypeRef::Reference(
Box::new(self_type),
self_param.lifetime().as_ref().map(LifetimeRef::new),
Mutability::Mut,
),
}
}
};
params.push(self_type);
has_self_param = true;
}
for param in param_list.params() {
let type_ref = TypeRef::from_ast_opt(&self.body_ctx, param.ty());
params.push(type_ref);
}
}
let mut is_varargs = false;
if let Some(params) = func.param_list() {
if let Some(last) = params.params().last() {
is_varargs = last.dotdotdot_token().is_some();
}
}
let ret_type = match func.ret_type().and_then(|rt| rt.ty()) {
Some(type_ref) => TypeRef::from_ast(&self.body_ctx, type_ref),
_ => TypeRef::unit(),
};
let ret_type = if func.async_token().is_some() {
let future_impl = desugar_future_path(ret_type);
let ty_bound = TypeBound::Path(future_impl);
TypeRef::ImplTrait(vec![ty_bound])
} else {
ret_type
};
let has_body = func.body().is_some();
let ast_id = self.source_ast_id_map.ast_id(func);
let mut res = Function {
name,
visibility,
generic_params: GenericParamsId::EMPTY,
has_self_param,
has_body,
is_unsafe: func.unsafe_token().is_some(),
is_extern: false,
params: params.into_boxed_slice(),
is_varargs,
ret_type,
ast_id,
};
res.generic_params = self.lower_generic_params(GenericsOwner::Function(&res), func);
Some(id(self.data().functions.alloc(res)))
}
fn lower_type_alias(
&mut self,
type_alias: &ast::TypeAlias,
) -> Option<FileItemTreeId<TypeAlias>> {
let name = type_alias.name()?.as_name();
let type_ref = type_alias.ty().map(|it| self.lower_type_ref(&it));
let visibility = self.lower_visibility(type_alias);
let bounds = self.lower_type_bounds(type_alias);
let generic_params = self.lower_generic_params(GenericsOwner::TypeAlias, type_alias);
let ast_id = self.source_ast_id_map.ast_id(type_alias);
let res = TypeAlias {
name,
visibility,
bounds: bounds.into_boxed_slice(),
generic_params,
type_ref,
ast_id,
is_extern: false,
};
Some(id(self.data().type_aliases.alloc(res)))
}
fn lower_static(&mut self, static_: &ast::Static) -> Option<FileItemTreeId<Static>> {
let name = static_.name()?.as_name();
let type_ref = self.lower_type_ref_opt(static_.ty());
let visibility = self.lower_visibility(static_);
let mutable = static_.mut_token().is_some();
let ast_id = self.source_ast_id_map.ast_id(static_);
let res = Static { name, visibility, mutable, type_ref, ast_id, is_extern: false };
Some(id(self.data().statics.alloc(res)))
}
fn lower_const(&mut self, konst: &ast::Const) -> FileItemTreeId<Const> {
let name = konst.name().map(|it| it.as_name());
let type_ref = self.lower_type_ref_opt(konst.ty());
let visibility = self.lower_visibility(konst);
let ast_id = self.source_ast_id_map.ast_id(konst);
let res = Const { name, visibility, type_ref, ast_id };
id(self.data().consts.alloc(res))
}
fn lower_module(&mut self, module: &ast::Module) -> Option<FileItemTreeId<Mod>> {
let name = module.name()?.as_name();
let visibility = self.lower_visibility(module);
let kind = if module.semicolon_token().is_some() {
ModKind::Outline {}
} else {
ModKind::Inline {
items: module
.item_list()
.map(|list| {
list.items()
.flat_map(|item| self.lower_mod_item(&item, false))
.flat_map(|items| items.0)
.collect()
})
.unwrap_or_else(|| {
mark::hit!(name_res_works_for_broken_modules);
Box::new([]) as Box<[_]>
}),
}
};
let ast_id = self.source_ast_id_map.ast_id(module);
let res = Mod { name, visibility, kind, ast_id };
Some(id(self.data().mods.alloc(res)))
}
fn lower_trait(&mut self, trait_def: &ast::Trait) -> Option<FileItemTreeId<Trait>> {
let name = trait_def.name()?.as_name();
let visibility = self.lower_visibility(trait_def);
let generic_params =
self.lower_generic_params_and_inner_items(GenericsOwner::Trait(trait_def), trait_def);
let auto = trait_def.auto_token().is_some();
let items = trait_def.assoc_item_list().map(|list| {
self.with_inherited_visibility(visibility, |this| {
list.assoc_items()
.filter_map(|item| {
let attrs = RawAttrs::new(&item, &this.hygiene);
this.collect_inner_items(item.syntax());
this.lower_assoc_item(&item).map(|item| {
this.add_attrs(ModItem::from(item).into(), attrs);
item
})
})
.collect()
})
});
let ast_id = self.source_ast_id_map.ast_id(trait_def);
let res = Trait {
name,
visibility,
generic_params,
auto,
items: items.unwrap_or_default(),
ast_id,
};
Some(id(self.data().traits.alloc(res)))
}
fn lower_impl(&mut self, impl_def: &ast::Impl) -> Option<FileItemTreeId<Impl>> {
let generic_params =
self.lower_generic_params_and_inner_items(GenericsOwner::Impl, impl_def);
let target_trait = impl_def.trait_().map(|tr| self.lower_type_ref(&tr));
let target_type = self.lower_type_ref(&impl_def.self_ty()?);
let is_negative = impl_def.excl_token().is_some();
// We cannot use `assoc_items()` here as that does not include macro calls.
let items = impl_def
.assoc_item_list()
.into_iter()
.flat_map(|it| it.assoc_items())
.filter_map(|item| {
self.collect_inner_items(item.syntax());
let assoc = self.lower_assoc_item(&item)?;
let attrs = RawAttrs::new(&item, &self.hygiene);
self.add_attrs(ModItem::from(assoc).into(), attrs);
Some(assoc)
})
.collect();
let ast_id = self.source_ast_id_map.ast_id(impl_def);
let res = Impl { generic_params, target_trait, target_type, is_negative, items, ast_id };
Some(id(self.data().impls.alloc(res)))
}
fn lower_use(&mut self, use_item: &ast::Use) -> Vec<FileItemTreeId<Import>> {
let visibility = self.lower_visibility(use_item);
let ast_id = self.source_ast_id_map.ast_id(use_item);
// Every use item can expand to many `Import`s.
let mut imports = Vec::new();
let tree = self.tree.data_mut();
ModPath::expand_use_item(
InFile::new(self.file, use_item.clone()),
&self.hygiene,
|path, _use_tree, is_glob, alias| {
imports.push(id(tree.imports.alloc(Import {
path,
alias,
visibility,
is_glob,
ast_id,
index: imports.len(),
})));
},
);
imports
}
fn lower_extern_crate(
&mut self,
extern_crate: &ast::ExternCrate,
) -> Option<FileItemTreeId<ExternCrate>> {
let name = extern_crate.name_ref()?.as_name();
let alias = extern_crate.rename().map(|a| {
a.name().map(|it| it.as_name()).map_or(ImportAlias::Underscore, ImportAlias::Alias)
});
let visibility = self.lower_visibility(extern_crate);
let ast_id = self.source_ast_id_map.ast_id(extern_crate);
let res = ExternCrate { name, alias, visibility, ast_id };
Some(id(self.data().extern_crates.alloc(res)))
}
fn lower_macro_call(&mut self, m: &ast::MacroCall) -> Option<FileItemTreeId<MacroCall>> {
let path = ModPath::from_src(m.path()?, &self.hygiene)?;
let ast_id = self.source_ast_id_map.ast_id(m);
let res = MacroCall { path, ast_id };
Some(id(self.data().macro_calls.alloc(res)))
}
fn lower_macro_rules(&mut self, m: &ast::MacroRules) -> Option<FileItemTreeId<MacroRules>> {
let name = m.name().map(|it| it.as_name())?;
let ast_id = self.source_ast_id_map.ast_id(m);
let res = MacroRules { name, ast_id };
Some(id(self.data().macro_rules.alloc(res)))
}
fn lower_macro_def(&mut self, m: &ast::MacroDef) -> Option<FileItemTreeId<MacroDef>> {
let name = m.name().map(|it| it.as_name())?;
let ast_id = self.source_ast_id_map.ast_id(m);
let visibility = self.lower_visibility(m);
let res = MacroDef { name, ast_id, visibility };
Some(id(self.data().macro_defs.alloc(res)))
}
fn lower_extern_block(&mut self, block: &ast::ExternBlock) -> Vec<ModItem> {
block.extern_item_list().map_or(Vec::new(), |list| {
list.extern_items()
.filter_map(|item| {
self.collect_inner_items(item.syntax());
let attrs = RawAttrs::new(&item, &self.hygiene);
let id: ModItem = match item {
ast::ExternItem::Fn(ast) => {
let func_id = self.lower_function(&ast)?;
let func = &mut self.data().functions[func_id.index];
func.is_unsafe = is_intrinsic_fn_unsafe(&func.name);
func.is_extern = true;
func_id.into()
}
ast::ExternItem::Static(ast) => {
let statik = self.lower_static(&ast)?;
self.data().statics[statik.index].is_extern = true;
statik.into()
}
ast::ExternItem::TypeAlias(ty) => {
let foreign_ty = self.lower_type_alias(&ty)?;
self.data().type_aliases[foreign_ty.index].is_extern = true;
foreign_ty.into()
}
ast::ExternItem::MacroCall(_) => return None,
};
self.add_attrs(id.into(), attrs);
Some(id)
})
.collect()
})
}
/// Lowers generics defined on `node` and collects inner items defined within.
fn lower_generic_params_and_inner_items(
&mut self,
owner: GenericsOwner<'_>,
node: &impl ast::GenericParamsOwner,
) -> GenericParamsId {
// Generics are part of item headers and may contain inner items we need to collect.
if let Some(params) = node.generic_param_list() {
self.collect_inner_items(params.syntax());
}
if let Some(clause) = node.where_clause() {
self.collect_inner_items(clause.syntax());
}
self.lower_generic_params(owner, node)
}
fn lower_generic_params(
&mut self,
owner: GenericsOwner<'_>,
node: &impl ast::GenericParamsOwner,
) -> GenericParamsId {
let mut sm = &mut Default::default();
let mut generics = GenericParams::default();
match owner {
GenericsOwner::Function(func) => {
generics.fill(&self.body_ctx, sm, node);
// lower `impl Trait` in arguments
for param in &*func.params {
generics.fill_implicit_impl_trait_args(param);
}
}
GenericsOwner::Struct
| GenericsOwner::Enum
| GenericsOwner::Union
| GenericsOwner::TypeAlias => {
generics.fill(&self.body_ctx, sm, node);
}
GenericsOwner::Trait(trait_def) => {
// traits get the Self type as an implicit first type parameter
let self_param_id = generics.types.alloc(TypeParamData {
name: Some(name![Self]),
default: None,
provenance: TypeParamProvenance::TraitSelf,
});
sm.type_params.insert(self_param_id, Either::Left(trait_def.clone()));
// add super traits as bounds on Self
// i.e., trait Foo: Bar is equivalent to trait Foo where Self: Bar
let self_param = TypeRef::Path(name![Self].into());
generics.fill_bounds(&self.body_ctx, trait_def, Either::Left(self_param));
generics.fill(&self.body_ctx, &mut sm, node);
}
GenericsOwner::Impl => {
// Note that we don't add `Self` here: in `impl`s, `Self` is not a
// type-parameter, but rather is a type-alias for impl's target
// type, so this is handled by the resolver.
generics.fill(&self.body_ctx, &mut sm, node);
}
}
self.data().generics.alloc(generics)
}
fn lower_type_bounds(&mut self, node: &impl ast::TypeBoundsOwner) -> Vec<TypeBound> {
match node.type_bound_list() {
Some(bound_list) => {
bound_list.bounds().map(|it| TypeBound::from_ast(&self.body_ctx, it)).collect()
}
None => Vec::new(),
}
}
fn lower_visibility(&mut self, item: &impl ast::VisibilityOwner) -> RawVisibilityId {
let vis = match self.forced_visibility {
Some(vis) => return vis,
None => RawVisibility::from_ast_with_hygiene(item.visibility(), &self.hygiene),
};
self.data().vis.alloc(vis)
}
fn lower_type_ref(&self, type_ref: &ast::Type) -> TypeRef {
TypeRef::from_ast(&self.body_ctx, type_ref.clone())
}
fn lower_type_ref_opt(&self, type_ref: Option<ast::Type>) -> TypeRef {
type_ref.map(|ty| self.lower_type_ref(&ty)).unwrap_or(TypeRef::Error)
}
/// Forces the visibility `vis` to be used for all items lowered during execution of `f`.
fn with_inherited_visibility<R>(
&mut self,
vis: RawVisibilityId,
f: impl FnOnce(&mut Self) -> R,
) -> R {
let old = mem::replace(&mut self.forced_visibility, Some(vis));
let res = f(self);
self.forced_visibility = old;
res
}
fn next_field_idx(&self) -> Idx<Field> {
Idx::from_raw(RawIdx::from(
self.tree.data.as_ref().map_or(0, |data| data.fields.len() as u32),
))
}
fn next_variant_idx(&self) -> Idx<Variant> {
Idx::from_raw(RawIdx::from(
self.tree.data.as_ref().map_or(0, |data| data.variants.len() as u32),
))
}
}
fn desugar_future_path(orig: TypeRef) -> Path {
let path = path![core::future::Future];
let mut generic_args: Vec<_> = std::iter::repeat(None).take(path.segments.len() - 1).collect();
let mut last = GenericArgs::empty();
let binding =
AssociatedTypeBinding { name: name![Output], type_ref: Some(orig), bounds: Vec::new() };
last.bindings.push(binding);
generic_args.push(Some(Arc::new(last)));
Path::from_known_path(path, generic_args)
}
enum GenericsOwner<'a> {
/// We need access to the partially-lowered `Function` for lowering `impl Trait` in argument
/// position.
Function(&'a Function),
Struct,
Enum,
Union,
/// The `TraitDef` is needed to fill the source map for the implicit `Self` parameter.
Trait(&'a ast::Trait),
TypeAlias,
Impl,
}
/// Returns `true` if the given intrinsic is unsafe to call, or false otherwise.
fn is_intrinsic_fn_unsafe(name: &Name) -> bool {
// Should be kept in sync with https://github.com/rust-lang/rust/blob/c6e4db620a7d2f569f11dcab627430921ea8aacf/compiler/rustc_typeck/src/check/intrinsic.rs#L68
![
known::abort,
known::min_align_of,
known::needs_drop,
known::caller_location,
known::size_of_val,
known::min_align_of_val,
known::add_with_overflow,
known::sub_with_overflow,
known::mul_with_overflow,
known::wrapping_add,
known::wrapping_sub,
known::wrapping_mul,
known::saturating_add,
known::saturating_sub,
known::rotate_left,
known::rotate_right,
known::ctpop,
known::ctlz,
known::cttz,
known::bswap,
known::bitreverse,
known::discriminant_value,
known::type_id,
known::likely,
known::unlikely,
known::ptr_guaranteed_eq,
known::ptr_guaranteed_ne,
known::minnumf32,
known::minnumf64,
known::maxnumf32,
known::rustc_peek,
known::maxnumf64,
known::type_name,
known::variant_count,
]
.contains(&name)
}