blob: 199b8daa37efe93aa31acf6700721a9b039de45c [file] [log] [blame]
//! AST -> `ItemTree` lowering code.
use std::collections::hash_map::Entry;
use hir_expand::{mod_path::path, name, name::AsName, span_map::SpanMapRef, HirFileId};
use la_arena::Arena;
use rustc_hash::FxHashMap;
use span::{AstIdMap, SyntaxContextId};
use syntax::{
ast::{self, HasModuleItem, HasName, HasTypeBounds, IsString},
AstNode,
};
use triomphe::Arc;
use crate::{
db::DefDatabase,
generics::{GenericParams, GenericParamsCollector, TypeParamData, TypeParamProvenance},
item_tree::{
AssocItem, AttrOwner, Const, Either, Enum, ExternBlock, ExternCrate, Field, FieldAstId,
Fields, FileItemTreeId, FnFlags, Function, GenericArgs, GenericModItem, Idx, IdxRange,
Impl, ImportAlias, Interned, ItemTree, ItemTreeData, ItemTreeNode, Macro2, MacroCall,
MacroRules, Mod, ModItem, ModKind, ModPath, Mutability, Name, Param, ParamAstId, Path,
Range, RawAttrs, RawIdx, RawVisibilityId, Static, Struct, StructKind, Trait, TraitAlias,
TypeAlias, Union, Use, UseTree, UseTreeKind, Variant,
},
path::AssociatedTypeBinding,
type_ref::{LifetimeRef, TraitBoundModifier, TraitRef, TypeBound, TypeRef},
visibility::RawVisibility,
LocalLifetimeParamId, LocalTypeOrConstParamId,
};
fn id<N: ItemTreeNode>(index: Idx<N>) -> FileItemTreeId<N> {
FileItemTreeId(index)
}
pub(super) struct Ctx<'a> {
db: &'a dyn DefDatabase,
tree: ItemTree,
source_ast_id_map: Arc<AstIdMap>,
generic_param_attr_buffer:
FxHashMap<Either<LocalTypeOrConstParamId, LocalLifetimeParamId>, RawAttrs>,
body_ctx: crate::lower::LowerCtx<'a>,
}
impl<'a> Ctx<'a> {
pub(super) fn new(db: &'a dyn DefDatabase, file: HirFileId) -> Self {
Self {
db,
tree: ItemTree::default(),
generic_param_attr_buffer: FxHashMap::default(),
source_ast_id_map: db.ast_id_map(file),
body_ctx: crate::lower::LowerCtx::new(db, file),
}
}
pub(super) fn span_map(&self) -> SpanMapRef<'_> {
self.body_ctx.span_map()
}
pub(super) fn lower_module_items(mut self, item_owner: &dyn HasModuleItem) -> ItemTree {
self.tree.top_level =
item_owner.items().flat_map(|item| self.lower_mod_item(&item)).collect();
assert!(self.generic_param_attr_buffer.is_empty());
self.tree
}
pub(super) fn lower_macro_stmts(mut self, stmts: ast::MacroStmts) -> ItemTree {
self.tree.top_level = stmts
.statements()
.filter_map(|stmt| {
match stmt {
ast::Stmt::Item(item) => Some(item),
// 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) => match es.expr()? {
ast::Expr::MacroExpr(expr) => {
cov_mark::hit!(macro_call_in_macro_stmts_is_added_to_item_tree);
Some(expr.macro_call()?.into())
}
_ => None,
},
_ => None,
}
})
.flat_map(|item| self.lower_mod_item(&item))
.collect();
if let Some(ast::Expr::MacroExpr(tail_macro)) = stmts.expr() {
if let Some(call) = tail_macro.macro_call() {
cov_mark::hit!(macro_stmt_with_trailing_macro_expr);
if let Some(mod_item) = self.lower_mod_item(&call.into()) {
self.tree.top_level.push(mod_item);
}
}
}
assert!(self.generic_param_attr_buffer.is_empty());
self.tree
}
pub(super) fn lower_block(mut self, block: &ast::BlockExpr) -> ItemTree {
self.tree
.attrs
.insert(AttrOwner::TopLevel, RawAttrs::new(self.db.upcast(), block, self.span_map()));
self.tree.top_level = block
.statements()
.filter_map(|stmt| match stmt {
ast::Stmt::Item(item) => self.lower_mod_item(&item),
// 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) => match es.expr()? {
ast::Expr::MacroExpr(expr) => self.lower_mod_item(&expr.macro_call()?.into()),
_ => None,
},
_ => None,
})
.collect();
if let Some(ast::Expr::MacroExpr(expr)) = block.tail_expr() {
if let Some(call) = expr.macro_call() {
if let Some(mod_item) = self.lower_mod_item(&call.into()) {
self.tree.top_level.push(mod_item);
}
}
}
assert!(self.generic_param_attr_buffer.is_empty());
self.tree
}
fn data(&mut self) -> &mut ItemTreeData {
self.tree.data_mut()
}
fn lower_mod_item(&mut self, item: &ast::Item) -> Option<ModItem> {
let mod_item: ModItem = match item {
ast::Item::Struct(ast) => self.lower_struct(ast)?.into(),
ast::Item::Union(ast) => self.lower_union(ast)?.into(),
ast::Item::Enum(ast) => self.lower_enum(ast)?.into(),
ast::Item::Fn(ast) => self.lower_function(ast)?.into(),
ast::Item::TypeAlias(ast) => self.lower_type_alias(ast)?.into(),
ast::Item::Static(ast) => self.lower_static(ast)?.into(),
ast::Item::Const(ast) => self.lower_const(ast).into(),
ast::Item::Module(ast) => self.lower_module(ast)?.into(),
ast::Item::Trait(ast) => self.lower_trait(ast)?.into(),
ast::Item::TraitAlias(ast) => self.lower_trait_alias(ast)?.into(),
ast::Item::Impl(ast) => self.lower_impl(ast)?.into(),
ast::Item::Use(ast) => self.lower_use(ast)?.into(),
ast::Item::ExternCrate(ast) => self.lower_extern_crate(ast)?.into(),
ast::Item::MacroCall(ast) => self.lower_macro_call(ast)?.into(),
ast::Item::MacroRules(ast) => self.lower_macro_rules(ast)?.into(),
ast::Item::MacroDef(ast) => self.lower_macro_def(ast)?.into(),
ast::Item::ExternBlock(ast) => self.lower_extern_block(ast).into(),
};
let attrs = RawAttrs::new(self.db.upcast(), item, self.span_map());
self.add_attrs(mod_item.into(), attrs);
Some(mod_item)
}
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 lower_assoc_item(&mut self, item_node: &ast::AssocItem) -> Option<AssocItem> {
let item: AssocItem = match item_node {
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),
}?;
let attrs = RawAttrs::new(self.db.upcast(), item_node, self.span_map());
self.add_attrs(
match item {
AssocItem::Function(it) => AttrOwner::ModItem(ModItem::Function(it)),
AssocItem::TypeAlias(it) => AttrOwner::ModItem(ModItem::TypeAlias(it)),
AssocItem::Const(it) => AttrOwner::ModItem(ModItem::Const(it)),
AssocItem::MacroCall(it) => AttrOwner::ModItem(ModItem::MacroCall(it)),
},
attrs,
);
Some(item)
}
fn lower_struct(&mut self, strukt: &ast::Struct) -> Option<FileItemTreeId<Struct>> {
let visibility = self.lower_visibility(strukt);
let name = strukt.name()?.as_name();
let ast_id = self.source_ast_id_map.ast_id(strukt);
let fields = self.lower_fields(&strukt.kind());
let generic_params = self.lower_generic_params(HasImplicitSelf::No, strukt);
let res = Struct { name, visibility, generic_params, fields, ast_id };
let id = id(self.data().structs.alloc(res));
self.write_generic_params_attributes(id.into());
Some(id)
}
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) -> IdxRange<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(self.db.upcast(), &field, self.span_map()),
);
}
}
let end = self.next_field_idx();
IdxRange::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 ast_id = FieldAstId::Record(self.source_ast_id_map.ast_id(field));
let res = Field { name, type_ref, visibility, ast_id };
Some(res)
}
fn lower_tuple_fields(&mut self, fields: &ast::TupleFieldList) -> IdxRange<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(self.db.upcast(), &field, self.span_map()));
}
let end = self.next_field_idx();
IdxRange::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 ast_id = FieldAstId::Tuple(self.source_ast_id_map.ast_id(field));
Field { name, type_ref, visibility, ast_id }
}
fn lower_union(&mut self, union: &ast::Union) -> Option<FileItemTreeId<Union>> {
let visibility = self.lower_visibility(union);
let name = union.name()?.as_name();
let ast_id = self.source_ast_id_map.ast_id(union);
let fields = match union.record_field_list() {
Some(record_field_list) => self.lower_fields(&StructKind::Record(record_field_list)),
None => Fields::Record(IdxRange::new(self.next_field_idx()..self.next_field_idx())),
};
let generic_params = self.lower_generic_params(HasImplicitSelf::No, union);
let res = Union { name, visibility, generic_params, fields, ast_id };
let id = id(self.data().unions.alloc(res));
self.write_generic_params_attributes(id.into());
Some(id)
}
fn lower_enum(&mut self, enum_: &ast::Enum) -> Option<FileItemTreeId<Enum>> {
let visibility = self.lower_visibility(enum_);
let name = enum_.name()?.as_name();
let ast_id = self.source_ast_id_map.ast_id(enum_);
let variants = match &enum_.variant_list() {
Some(variant_list) => self.lower_variants(variant_list),
None => {
FileItemTreeId(self.next_variant_idx())..FileItemTreeId(self.next_variant_idx())
}
};
let generic_params = self.lower_generic_params(HasImplicitSelf::No, enum_);
let res = Enum { name, visibility, generic_params, variants, ast_id };
let id = id(self.data().enums.alloc(res));
self.write_generic_params_attributes(id.into());
Some(id)
}
fn lower_variants(&mut self, variants: &ast::VariantList) -> Range<FileItemTreeId<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(
id(idx).into(),
RawAttrs::new(self.db.upcast(), &variant, self.span_map()),
);
}
}
let end = self.next_variant_idx();
FileItemTreeId(start)..FileItemTreeId(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 ast_id = self.source_ast_id_map.ast_id(variant);
let res = Variant { name, fields, ast_id };
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 has_self_param = false;
let start_param = self.next_param_idx();
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,
),
}
}
};
let type_ref = Interned::new(self_type);
let ast_id = self.source_ast_id_map.ast_id(&self_param);
let idx = self.data().params.alloc(Param {
type_ref: Some(type_ref),
ast_id: ParamAstId::SelfParam(ast_id),
});
self.add_attrs(
idx.into(),
RawAttrs::new(self.db.upcast(), &self_param, self.span_map()),
);
has_self_param = true;
}
for param in param_list.params() {
let ast_id = self.source_ast_id_map.ast_id(&param);
let idx = match param.dotdotdot_token() {
Some(_) => self
.data()
.params
.alloc(Param { type_ref: None, ast_id: ParamAstId::Param(ast_id) }),
None => {
let type_ref = TypeRef::from_ast_opt(&self.body_ctx, param.ty());
let ty = Interned::new(type_ref);
self.data()
.params
.alloc(Param { type_ref: Some(ty), ast_id: ParamAstId::Param(ast_id) })
}
};
self.add_attrs(
idx.into(),
RawAttrs::new(self.db.upcast(), &param, self.span_map()),
);
}
}
let end_param = self.next_param_idx();
let params = IdxRange::new(start_param..end_param);
let ret_type = match func.ret_type() {
Some(rt) => match rt.ty() {
Some(type_ref) => TypeRef::from_ast(&self.body_ctx, type_ref),
None if rt.thin_arrow_token().is_some() => TypeRef::Error,
None => TypeRef::unit(),
},
None => TypeRef::unit(),
};
let ret_type = if func.async_token().is_some() {
let future_impl = desugar_future_path(ret_type);
let ty_bound = Interned::new(TypeBound::Path(future_impl, TraitBoundModifier::None));
TypeRef::ImplTrait(vec![ty_bound])
} else {
ret_type
};
let abi = func.abi().map(lower_abi);
let ast_id = self.source_ast_id_map.ast_id(func);
let mut flags = FnFlags::default();
if func.body().is_some() {
flags |= FnFlags::HAS_BODY;
}
if has_self_param {
flags |= FnFlags::HAS_SELF_PARAM;
}
if func.default_token().is_some() {
flags |= FnFlags::HAS_DEFAULT_KW;
}
if func.const_token().is_some() {
flags |= FnFlags::HAS_CONST_KW;
}
if func.async_token().is_some() {
flags |= FnFlags::HAS_ASYNC_KW;
}
if func.unsafe_token().is_some() {
flags |= FnFlags::HAS_UNSAFE_KW;
}
let res = Function {
name,
visibility,
explicit_generic_params: self.lower_generic_params(HasImplicitSelf::No, func),
abi,
params,
ret_type: Interned::new(ret_type),
ast_id,
flags,
};
let id = id(self.data().functions.alloc(res));
self.write_generic_params_attributes(id.into());
Some(id)
}
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 ast_id = self.source_ast_id_map.ast_id(type_alias);
let generic_params = self.lower_generic_params(HasImplicitSelf::No, type_alias);
let res = TypeAlias { name, visibility, bounds, generic_params, type_ref, ast_id };
let id = id(self.data().type_aliases.alloc(res));
self.write_generic_params_attributes(id.into());
Some(id)
}
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 };
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, has_body: konst.body().is_some() };
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)).collect())
.unwrap_or_else(|| {
cov_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 ast_id = self.source_ast_id_map.ast_id(trait_def);
let is_auto = trait_def.auto_token().is_some();
let is_unsafe = trait_def.unsafe_token().is_some();
let items = trait_def
.assoc_item_list()
.into_iter()
.flat_map(|list| list.assoc_items())
.filter_map(|item_node| self.lower_assoc_item(&item_node))
.collect();
let generic_params =
self.lower_generic_params(HasImplicitSelf::Yes(trait_def.type_bound_list()), trait_def);
let def = Trait { name, visibility, generic_params, is_auto, is_unsafe, items, ast_id };
let id = id(self.data().traits.alloc(def));
self.write_generic_params_attributes(id.into());
Some(id)
}
fn lower_trait_alias(
&mut self,
trait_alias_def: &ast::TraitAlias,
) -> Option<FileItemTreeId<TraitAlias>> {
let name = trait_alias_def.name()?.as_name();
let visibility = self.lower_visibility(trait_alias_def);
let ast_id = self.source_ast_id_map.ast_id(trait_alias_def);
let generic_params = self.lower_generic_params(
HasImplicitSelf::Yes(trait_alias_def.type_bound_list()),
trait_alias_def,
);
let alias = TraitAlias { name, visibility, generic_params, ast_id };
let id = id(self.data().trait_aliases.alloc(alias));
self.write_generic_params_attributes(id.into());
Some(id)
}
fn lower_impl(&mut self, impl_def: &ast::Impl) -> Option<FileItemTreeId<Impl>> {
let ast_id = self.source_ast_id_map.ast_id(impl_def);
// FIXME: If trait lowering fails, due to a non PathType for example, we treat this impl
// as if it was an non-trait impl. Ideally we want to create a unique missing ref that only
// equals itself.
let self_ty = self.lower_type_ref(&impl_def.self_ty()?);
let target_trait = impl_def.trait_().and_then(|tr| self.lower_trait_ref(&tr));
let is_negative = impl_def.excl_token().is_some();
let is_unsafe = impl_def.unsafe_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.lower_assoc_item(&item))
.collect();
// Note that trait impls don't get implicit `Self` unlike traits, because here they are a
// type alias rather than a type parameter, so this is handled by the resolver.
let generic_params = self.lower_generic_params(HasImplicitSelf::No, impl_def);
let res =
Impl { generic_params, target_trait, self_ty, is_negative, is_unsafe, items, ast_id };
let id = id(self.data().impls.alloc(res));
self.write_generic_params_attributes(id.into());
Some(id)
}
fn lower_use(&mut self, use_item: &ast::Use) -> Option<FileItemTreeId<Use>> {
let visibility = self.lower_visibility(use_item);
let ast_id = self.source_ast_id_map.ast_id(use_item);
let (use_tree, _) = lower_use_tree(self.db, use_item.use_tree()?, &mut |range| {
self.span_map().span_for_range(range).ctx
})?;
let res = Use { visibility, ast_id, use_tree };
Some(id(self.data().uses.alloc(res)))
}
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 span_map = self.span_map();
let path = m.path()?;
let range = path.syntax().text_range();
let path = Interned::new(ModPath::from_src(self.db.upcast(), path, &mut |range| {
span_map.span_for_range(range).ctx
})?);
let ast_id = self.source_ast_id_map.ast_id(m);
let expand_to = hir_expand::ExpandTo::from_call_site(m);
let res = MacroCall { path, ast_id, expand_to, ctxt: span_map.span_for_range(range).ctx };
Some(id(self.data().macro_calls.alloc(res)))
}
fn lower_macro_rules(&mut self, m: &ast::MacroRules) -> Option<FileItemTreeId<MacroRules>> {
let name = m.name()?;
let ast_id = self.source_ast_id_map.ast_id(m);
let res = MacroRules { name: name.as_name(), ast_id };
Some(id(self.data().macro_rules.alloc(res)))
}
fn lower_macro_def(&mut self, m: &ast::MacroDef) -> Option<FileItemTreeId<Macro2>> {
let name = m.name()?;
let ast_id = self.source_ast_id_map.ast_id(m);
let visibility = self.lower_visibility(m);
let res = Macro2 { name: name.as_name(), ast_id, visibility };
Some(id(self.data().macro_defs.alloc(res)))
}
fn lower_extern_block(&mut self, block: &ast::ExternBlock) -> FileItemTreeId<ExternBlock> {
let ast_id = self.source_ast_id_map.ast_id(block);
let abi = block.abi().map(lower_abi);
let children: Box<[_]> = block.extern_item_list().map_or(Box::new([]), |list| {
list.extern_items()
.filter_map(|item| {
// Note: All items in an `extern` block need to be lowered as if they're outside of one
// (in other words, the knowledge that they're in an extern block must not be used).
// This is because an extern block can contain macros whose ItemTree's top-level items
// should be considered to be in an extern block too.
let mod_item: ModItem = match &item {
ast::ExternItem::Fn(ast) => self.lower_function(ast)?.into(),
ast::ExternItem::Static(ast) => self.lower_static(ast)?.into(),
ast::ExternItem::TypeAlias(ty) => self.lower_type_alias(ty)?.into(),
ast::ExternItem::MacroCall(call) => self.lower_macro_call(call)?.into(),
};
let attrs = RawAttrs::new(self.db.upcast(), &item, self.span_map());
self.add_attrs(mod_item.into(), attrs);
Some(mod_item)
})
.collect()
});
let res = ExternBlock { abi, ast_id, children };
id(self.data().extern_blocks.alloc(res))
}
fn write_generic_params_attributes(&mut self, parent: GenericModItem) {
self.generic_param_attr_buffer.drain().for_each(|(idx, attrs)| {
self.tree.attrs.insert(
match idx {
Either::Left(id) => AttrOwner::TypeOrConstParamData(parent, id),
Either::Right(id) => AttrOwner::LifetimeParamData(parent, id),
},
attrs,
);
})
}
fn lower_generic_params(
&mut self,
has_implicit_self: HasImplicitSelf,
node: &dyn ast::HasGenericParams,
) -> Interned<GenericParams> {
debug_assert!(self.generic_param_attr_buffer.is_empty(),);
let add_param_attrs = |item: Either<LocalTypeOrConstParamId, LocalLifetimeParamId>,
param| {
let attrs = RawAttrs::new(self.db.upcast(), &param, self.body_ctx.span_map());
debug_assert!(self.generic_param_attr_buffer.insert(item, attrs).is_none());
};
self.body_ctx.take_impl_traits_bounds();
let mut generics = GenericParamsCollector::default();
if let HasImplicitSelf::Yes(bounds) = has_implicit_self {
// Traits and trait aliases get the Self type as an implicit first type parameter.
generics.type_or_consts.alloc(
TypeParamData {
name: Some(name![Self]),
default: None,
provenance: TypeParamProvenance::TraitSelf,
}
.into(),
);
// add super traits as bounds on Self
// i.e., `trait Foo: Bar` is equivalent to `trait Foo where Self: Bar`
generics.fill_bounds(
&self.body_ctx,
bounds,
Either::Left(TypeRef::Path(name![Self].into())),
);
}
generics.fill(&self.body_ctx, node, add_param_attrs);
Interned::new(generics.finish())
}
fn lower_type_bounds(&mut self, node: &dyn ast::HasTypeBounds) -> Box<[Interned<TypeBound>]> {
match node.type_bound_list() {
Some(bound_list) => bound_list
.bounds()
.map(|it| Interned::new(TypeBound::from_ast(&self.body_ctx, it)))
.collect(),
None => Box::default(),
}
}
fn lower_visibility(&mut self, item: &dyn ast::HasVisibility) -> RawVisibilityId {
let vis = RawVisibility::from_ast(self.db, item.visibility(), &mut |range| {
self.span_map().span_for_range(range).ctx
});
self.data().vis.alloc(vis)
}
fn lower_trait_ref(&mut self, trait_ref: &ast::Type) -> Option<Interned<TraitRef>> {
let trait_ref = TraitRef::from_ast(&self.body_ctx, trait_ref.clone())?;
Some(Interned::new(trait_ref))
}
fn lower_type_ref(&mut self, type_ref: &ast::Type) -> Interned<TypeRef> {
let tyref = TypeRef::from_ast(&self.body_ctx, type_ref.clone());
Interned::new(tyref)
}
fn lower_type_ref_opt(&mut self, type_ref: Option<ast::Type>) -> Interned<TypeRef> {
match type_ref.map(|ty| self.lower_type_ref(&ty)) {
Some(it) => it,
None => Interned::new(TypeRef::Error),
}
}
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 next_param_idx(&self) -> Idx<Param> {
Idx::from_raw(RawIdx::from(
self.tree.data.as_ref().map_or(0, |data| data.params.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 binding = AssociatedTypeBinding {
name: name![Output],
args: None,
type_ref: Some(orig),
bounds: Box::default(),
};
generic_args.push(Some(Interned::new(GenericArgs {
bindings: Box::new([binding]),
..GenericArgs::empty()
})));
Path::from_known_path(path, generic_args)
}
enum HasImplicitSelf {
/// Inner list is a type bound list for the implicit `Self`.
Yes(Option<ast::TypeBoundList>),
No,
}
fn lower_abi(abi: ast::Abi) -> Interned<str> {
match abi.abi_string() {
Some(tok) => Interned::new_str(tok.text_without_quotes()),
// `extern` default to be `extern "C"`.
_ => Interned::new_str("C"),
}
}
struct UseTreeLowering<'a> {
db: &'a dyn DefDatabase,
mapping: Arena<ast::UseTree>,
}
impl UseTreeLowering<'_> {
fn lower_use_tree(
&mut self,
tree: ast::UseTree,
span_for_range: &mut dyn FnMut(::tt::TextRange) -> SyntaxContextId,
) -> Option<UseTree> {
if let Some(use_tree_list) = tree.use_tree_list() {
let prefix = match tree.path() {
// E.g. use something::{{{inner}}};
None => None,
// E.g. `use something::{inner}` (prefix is `None`, path is `something`)
// or `use something::{path::{inner::{innerer}}}` (prefix is `something::path`, path is `inner`)
Some(path) => {
match ModPath::from_src(self.db.upcast(), path, span_for_range) {
Some(it) => Some(it),
None => return None, // FIXME: report errors somewhere
}
}
};
let list = use_tree_list
.use_trees()
.filter_map(|tree| self.lower_use_tree(tree, span_for_range))
.collect();
Some(
self.use_tree(
UseTreeKind::Prefixed { prefix: prefix.map(Interned::new), list },
tree,
),
)
} else {
let is_glob = tree.star_token().is_some();
let path = match tree.path() {
Some(path) => Some(ModPath::from_src(self.db.upcast(), path, span_for_range)?),
None => None,
};
let alias = tree.rename().map(|a| {
a.name().map(|it| it.as_name()).map_or(ImportAlias::Underscore, ImportAlias::Alias)
});
if alias.is_some() && is_glob {
return None;
}
match (path, alias, is_glob) {
(path, None, true) => {
if path.is_none() {
cov_mark::hit!(glob_enum_group);
}
Some(self.use_tree(UseTreeKind::Glob { path: path.map(Interned::new) }, tree))
}
// Globs can't be renamed
(_, Some(_), true) | (None, None, false) => None,
// `bla::{ as Name}` is invalid
(None, Some(_), false) => None,
(Some(path), alias, false) => Some(
self.use_tree(UseTreeKind::Single { path: Interned::new(path), alias }, tree),
),
}
}
}
fn use_tree(&mut self, kind: UseTreeKind, ast: ast::UseTree) -> UseTree {
let index = self.mapping.alloc(ast);
UseTree { index, kind }
}
}
pub(crate) fn lower_use_tree(
db: &dyn DefDatabase,
tree: ast::UseTree,
span_for_range: &mut dyn FnMut(::tt::TextRange) -> SyntaxContextId,
) -> Option<(UseTree, Arena<ast::UseTree>)> {
let mut lowering = UseTreeLowering { db, mapping: Arena::new() };
let tree = lowering.lower_use_tree(tree, span_for_range)?;
Some((tree, lowering.mapping))
}