]>
Commit | Line | Data |
---|---|---|
add651ee | 1 | use super::errors::{InvalidAbi, InvalidAbiReason, InvalidAbiSuggestion, MisplacedRelaxTraitBound}; |
923072b8 | 2 | use super::ResolverAstLoweringExt; |
9c376795 | 3 | use super::{AstOwner, ImplTraitContext, ImplTraitPosition}; |
064997fb | 4 | use super::{FnDeclKind, LoweringContext, ParamMode}; |
dfeec247 | 5 | |
fe692bf9 | 6 | use hir::definitions::DefPathData; |
ba9703b0 | 7 | use rustc_ast::ptr::P; |
5e7ed085 | 8 | use rustc_ast::visit::AssocCtxt; |
3dfed10e | 9 | use rustc_ast::*; |
5e7ed085 | 10 | use rustc_data_structures::sorted_map::SortedMap; |
9ffffee4 | 11 | use rustc_errors::ErrorGuaranteed; |
dfeec247 XL |
12 | use rustc_hir as hir; |
13 | use rustc_hir::def::{DefKind, Res}; | |
5e7ed085 | 14 | use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID}; |
04454e1e | 15 | use rustc_hir::PredicateOrigin; |
49aad941 | 16 | use rustc_index::{Idx, IndexSlice, IndexVec}; |
353b0b11 | 17 | use rustc_middle::ty::{ResolverAstLowering, TyCtxt}; |
9ffffee4 | 18 | use rustc_span::edit_distance::find_best_match_for_name; |
f9f354fc | 19 | use rustc_span::symbol::{kw, sym, Ident}; |
ed00b5ec | 20 | use rustc_span::{DesugaringKind, Span, Symbol}; |
60c5eb7d | 21 | use rustc_target::spec::abi; |
dfeec247 | 22 | use smallvec::{smallvec, SmallVec}; |
487cf647 | 23 | use thin_vec::ThinVec; |
6a06907d | 24 | |
5e7ed085 | 25 | pub(super) struct ItemLowerer<'a, 'hir> { |
064997fb | 26 | pub(super) tcx: TyCtxt<'hir>, |
923072b8 | 27 | pub(super) resolver: &'a mut ResolverAstLowering, |
353b0b11 | 28 | pub(super) ast_index: &'a IndexSlice<LocalDefId, AstOwner<'a>>, |
5e7ed085 | 29 | pub(super) owners: &'a mut IndexVec<LocalDefId, hir::MaybeOwner<&'hir hir::OwnerInfo<'hir>>>, |
416331ca XL |
30 | } |
31 | ||
5e7ed085 FG |
32 | /// When we have a ty alias we *may* have two where clauses. To give the best diagnostics, we set the span |
33 | /// to the where clause that is preferred, if it exists. Otherwise, it sets the span to the other where | |
34 | /// clause if it exists. | |
35 | fn add_ty_alias_where_clause( | |
36 | generics: &mut ast::Generics, | |
37 | mut where_clauses: (TyAliasWhereClause, TyAliasWhereClause), | |
38 | prefer_first: bool, | |
39 | ) { | |
40 | if !prefer_first { | |
41 | where_clauses = (where_clauses.1, where_clauses.0); | |
42 | } | |
43 | if where_clauses.0.0 || !where_clauses.1.0 { | |
44 | generics.where_clause.has_where_token = where_clauses.0.0; | |
45 | generics.where_clause.span = where_clauses.0.1; | |
46 | } else { | |
47 | generics.where_clause.has_where_token = where_clauses.1.0; | |
48 | generics.where_clause.span = where_clauses.1.1; | |
416331ca XL |
49 | } |
50 | } | |
51 | ||
5e7ed085 FG |
52 | impl<'a, 'hir> ItemLowerer<'a, 'hir> { |
53 | fn with_lctx( | |
54 | &mut self, | |
55 | owner: NodeId, | |
56 | f: impl FnOnce(&mut LoweringContext<'_, 'hir>) -> hir::OwnerNode<'hir>, | |
57 | ) { | |
add651ee FG |
58 | let allow_gen_future = Some(if self.tcx.features().async_fn_track_caller { |
59 | [sym::gen_future, sym::closure_track_caller][..].into() | |
60 | } else { | |
61 | [sym::gen_future][..].into() | |
62 | }); | |
5e7ed085 FG |
63 | let mut lctx = LoweringContext { |
64 | // Pseudo-globals. | |
064997fb | 65 | tcx: self.tcx, |
5e7ed085 | 66 | resolver: self.resolver, |
064997fb | 67 | arena: self.tcx.hir_arena, |
5e7ed085 FG |
68 | |
69 | // HirId handling. | |
70 | bodies: Vec::new(), | |
71 | attrs: SortedMap::default(), | |
487cf647 | 72 | children: Vec::default(), |
2b03887a | 73 | current_hir_id_owner: hir::CRATE_OWNER_ID, |
5e7ed085 FG |
74 | item_local_id_counter: hir::ItemLocalId::new(0), |
75 | node_id_to_local_id: Default::default(), | |
5e7ed085 FG |
76 | trait_map: Default::default(), |
77 | ||
78 | // Lowering state. | |
79 | catch_scope: None, | |
80 | loop_scope: None, | |
81 | is_in_loop_condition: false, | |
82 | is_in_trait_impl: false, | |
83 | is_in_dyn_type: false, | |
ed00b5ec | 84 | coroutine_kind: None, |
5e7ed085 FG |
85 | task_context: None, |
86 | current_item: None, | |
923072b8 FG |
87 | impl_trait_defs: Vec::new(), |
88 | impl_trait_bounds: Vec::new(), | |
04454e1e | 89 | allow_try_trait: Some([sym::try_trait_v2, sym::yeet_desugar_details][..].into()), |
add651ee | 90 | allow_gen_future, |
f2b60f7d | 91 | generics_def_id_map: Default::default(), |
add651ee | 92 | host_param_id: None, |
5e7ed085 FG |
93 | }; |
94 | lctx.with_hir_id_owner(owner, |lctx| f(lctx)); | |
3c0e092e | 95 | |
5e7ed085 | 96 | for (def_id, info) in lctx.children { |
49aad941 FG |
97 | let owner = self.owners.ensure_contains_elem(def_id, || hir::MaybeOwner::Phantom); |
98 | debug_assert!(matches!(owner, hir::MaybeOwner::Phantom)); | |
99 | *owner = info; | |
5e7ed085 | 100 | } |
416331ca XL |
101 | } |
102 | ||
5e7ed085 FG |
103 | pub(super) fn lower_node( |
104 | &mut self, | |
105 | def_id: LocalDefId, | |
106 | ) -> hir::MaybeOwner<&'hir hir::OwnerInfo<'hir>> { | |
49aad941 FG |
107 | let owner = self.owners.ensure_contains_elem(def_id, || hir::MaybeOwner::Phantom); |
108 | if let hir::MaybeOwner::Phantom = owner { | |
5e7ed085 FG |
109 | let node = self.ast_index[def_id]; |
110 | match node { | |
111 | AstOwner::NonOwner => {} | |
112 | AstOwner::Crate(c) => self.lower_crate(c), | |
113 | AstOwner::Item(item) => self.lower_item(item), | |
114 | AstOwner::AssocItem(item, ctxt) => self.lower_assoc_item(item, ctxt), | |
115 | AstOwner::ForeignItem(item) => self.lower_foreign_item(item), | |
3dfed10e | 116 | } |
3dfed10e | 117 | } |
3dfed10e | 118 | |
5e7ed085 | 119 | self.owners[def_id] |
416331ca | 120 | } |
fc512014 | 121 | |
923072b8 | 122 | #[instrument(level = "debug", skip(self, c))] |
5e7ed085 | 123 | fn lower_crate(&mut self, c: &Crate) { |
923072b8 | 124 | debug_assert_eq!(self.resolver.node_id_to_def_id[&CRATE_NODE_ID], CRATE_DEF_ID); |
5e7ed085 | 125 | self.with_lctx(CRATE_NODE_ID, |lctx| { |
04454e1e | 126 | let module = lctx.lower_mod(&c.items, &c.spans); |
5e7ed085 | 127 | lctx.lower_attrs(hir::CRATE_HIR_ID, &c.attrs); |
f2b60f7d | 128 | hir::OwnerNode::Crate(module) |
5e7ed085 | 129 | }) |
fc512014 | 130 | } |
416331ca | 131 | |
923072b8 | 132 | #[instrument(level = "debug", skip(self))] |
5e7ed085 FG |
133 | fn lower_item(&mut self, item: &Item) { |
134 | self.with_lctx(item.id, |lctx| hir::OwnerNode::Item(lctx.lower_item(item))) | |
416331ca XL |
135 | } |
136 | ||
5e7ed085 | 137 | fn lower_assoc_item(&mut self, item: &AssocItem, ctxt: AssocCtxt) { |
923072b8 | 138 | let def_id = self.resolver.node_id_to_def_id[&item.id]; |
e1599b0c | 139 | |
064997fb | 140 | let parent_id = self.tcx.local_parent(def_id); |
04454e1e | 141 | let parent_hir = self.lower_node(parent_id).unwrap(); |
5e7ed085 FG |
142 | self.with_lctx(item.id, |lctx| { |
143 | // Evaluate with the lifetimes in `params` in-scope. | |
144 | // This is used to track which lifetimes have already been defined, | |
145 | // and which need to be replicated when lowering an async fn. | |
49aad941 | 146 | |
add651ee FG |
147 | match parent_hir.node().expect_item().kind { |
148 | hir::ItemKind::Impl(impl_) => { | |
149 | lctx.is_in_trait_impl = impl_.of_trait.is_some(); | |
150 | } | |
151 | hir::ItemKind::Trait(_, _, generics, _, _) if lctx.tcx.features().effects => { | |
152 | lctx.host_param_id = generics | |
153 | .params | |
154 | .iter() | |
155 | .find(|param| { | |
156 | parent_hir | |
157 | .attrs | |
158 | .get(param.hir_id.local_id) | |
159 | .iter() | |
160 | .any(|attr| attr.has_name(sym::rustc_host)) | |
161 | }) | |
162 | .map(|param| param.def_id); | |
163 | } | |
164 | _ => {} | |
49aad941 | 165 | } |
e1599b0c | 166 | |
5e7ed085 FG |
167 | match ctxt { |
168 | AssocCtxt::Trait => hir::OwnerNode::TraitItem(lctx.lower_trait_item(item)), | |
169 | AssocCtxt::Impl => hir::OwnerNode::ImplItem(lctx.lower_impl_item(item)), | |
170 | } | |
171 | }) | |
172 | } | |
e1599b0c | 173 | |
5e7ed085 FG |
174 | fn lower_foreign_item(&mut self, item: &ForeignItem) { |
175 | self.with_lctx(item.id, |lctx| hir::OwnerNode::ForeignItem(lctx.lower_foreign_item(item))) | |
e1599b0c | 176 | } |
5e7ed085 | 177 | } |
e1599b0c | 178 | |
5e7ed085 | 179 | impl<'hir> LoweringContext<'_, 'hir> { |
f2b60f7d FG |
180 | pub(super) fn lower_mod( |
181 | &mut self, | |
182 | items: &[P<Item>], | |
183 | spans: &ModSpans, | |
184 | ) -> &'hir hir::Mod<'hir> { | |
185 | self.arena.alloc(hir::Mod { | |
04454e1e FG |
186 | spans: hir::ModSpans { |
187 | inner_span: self.lower_span(spans.inner_span), | |
188 | inject_use_span: self.lower_span(spans.inject_use_span), | |
189 | }, | |
c295e0f8 | 190 | item_ids: self.arena.alloc_from_iter(items.iter().flat_map(|x| self.lower_item_ref(x))), |
f2b60f7d | 191 | }) |
416331ca XL |
192 | } |
193 | ||
c295e0f8 | 194 | pub(super) fn lower_item_ref(&mut self, i: &Item) -> SmallVec<[hir::ItemId; 1]> { |
2b03887a FG |
195 | let mut node_ids = |
196 | smallvec![hir::ItemId { owner_id: hir::OwnerId { def_id: self.local_def_id(i.id) } }]; | |
487cf647 FG |
197 | if let ItemKind::Use(use_tree) = &i.kind { |
198 | self.lower_item_id_use_tree(use_tree, &mut node_ids); | |
c295e0f8 | 199 | } |
dfeec247 | 200 | node_ids |
416331ca XL |
201 | } |
202 | ||
487cf647 FG |
203 | fn lower_item_id_use_tree(&mut self, tree: &UseTree, vec: &mut SmallVec<[hir::ItemId; 1]>) { |
204 | match &tree.kind { | |
205 | UseTreeKind::Nested(nested_vec) => { | |
dfeec247 | 206 | for &(ref nested, id) in nested_vec { |
2b03887a FG |
207 | vec.push(hir::ItemId { |
208 | owner_id: hir::OwnerId { def_id: self.local_def_id(id) }, | |
209 | }); | |
487cf647 | 210 | self.lower_item_id_use_tree(nested, vec); |
416331ca | 211 | } |
dfeec247 | 212 | } |
487cf647 | 213 | UseTreeKind::Simple(..) | UseTreeKind::Glob => {} |
416331ca XL |
214 | } |
215 | } | |
216 | ||
c295e0f8 | 217 | fn lower_item(&mut self, i: &Item) -> &'hir hir::Item<'hir> { |
416331ca | 218 | let mut ident = i.ident; |
04454e1e | 219 | let vis_span = self.lower_span(i.vis.span); |
6a06907d XL |
220 | let hir_id = self.lower_node_id(i.id); |
221 | let attrs = self.lower_attrs(hir_id, &i.attrs); | |
04454e1e | 222 | let kind = self.lower_item_kind(i.span, i.id, hir_id, &mut ident, attrs, vis_span, &i.kind); |
c295e0f8 | 223 | let item = hir::Item { |
2b03887a | 224 | owner_id: hir_id.expect_owner(), |
94222f64 XL |
225 | ident: self.lower_ident(ident), |
226 | kind, | |
04454e1e | 227 | vis_span, |
94222f64 | 228 | span: self.lower_span(i.span), |
c295e0f8 XL |
229 | }; |
230 | self.arena.alloc(item) | |
416331ca XL |
231 | } |
232 | ||
233 | fn lower_item_kind( | |
234 | &mut self, | |
dfeec247 | 235 | span: Span, |
416331ca | 236 | id: NodeId, |
6a06907d | 237 | hir_id: hir::HirId, |
416331ca | 238 | ident: &mut Ident, |
6a06907d | 239 | attrs: Option<&'hir [Attribute]>, |
04454e1e | 240 | vis_span: Span, |
416331ca | 241 | i: &ItemKind, |
dfeec247 | 242 | ) -> hir::ItemKind<'hir> { |
487cf647 FG |
243 | match i { |
244 | ItemKind::ExternCrate(orig_name) => hir::ItemKind::ExternCrate(*orig_name), | |
245 | ItemKind::Use(use_tree) => { | |
416331ca | 246 | // Start with an empty prefix. |
487cf647 | 247 | let prefix = Path { segments: ThinVec::new(), span: use_tree.span, tokens: None }; |
416331ca | 248 | |
04454e1e | 249 | self.lower_use_tree(use_tree, &prefix, id, vis_span, ident, attrs) |
416331ca | 250 | } |
353b0b11 | 251 | ItemKind::Static(box ast::StaticItem { ty: t, mutability: m, expr: e }) => { |
74b04a01 | 252 | let (ty, body_id) = self.lower_const_item(t, span, e.as_deref()); |
487cf647 | 253 | hir::ItemKind::Static(ty, *m, body_id) |
416331ca | 254 | } |
add651ee FG |
255 | ItemKind::Const(box ast::ConstItem { generics, ty, expr, .. }) => { |
256 | let (generics, (ty, body_id)) = self.lower_generics( | |
257 | generics, | |
258 | Const::No, | |
259 | id, | |
260 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), | |
261 | |this| this.lower_const_item(ty, span, expr.as_deref()), | |
262 | ); | |
263 | hir::ItemKind::Const(ty, generics, body_id) | |
416331ca | 264 | } |
3c0e092e | 265 | ItemKind::Fn(box Fn { |
487cf647 FG |
266 | sig: FnSig { decl, header, span: fn_sig_span }, |
267 | generics, | |
268 | body, | |
3c0e092e XL |
269 | .. |
270 | }) => { | |
416331ca XL |
271 | self.with_new_scopes(|this| { |
272 | this.current_item = Some(ident.span); | |
273 | ||
274 | // Note: we don't need to change the return type from `T` to | |
275 | // `impl Future<Output = T>` here because lower_body | |
276 | // only cares about the input argument patterns in the function | |
277 | // declaration (decl), not the return types. | |
74b04a01 | 278 | let asyncness = header.asyncness; |
487cf647 FG |
279 | let body_id = this.lower_maybe_async_body( |
280 | span, | |
281 | hir_id, | |
282 | &decl, | |
283 | asyncness, | |
284 | body.as_deref(), | |
285 | ); | |
416331ca | 286 | |
9c376795 | 287 | let itctx = ImplTraitContext::Universal; |
fe692bf9 FG |
288 | let (generics, decl) = |
289 | this.lower_generics(generics, header.constness, id, &itctx, |this| { | |
290 | let ret_id = asyncness.opt_return_id(); | |
291 | this.lower_fn_decl(&decl, id, *fn_sig_span, FnDeclKind::Fn, ret_id) | |
292 | }); | |
3dfed10e XL |
293 | let sig = hir::FnSig { |
294 | decl, | |
487cf647 FG |
295 | header: this.lower_fn_header(*header), |
296 | span: this.lower_span(*fn_sig_span), | |
3dfed10e | 297 | }; |
60c5eb7d | 298 | hir::ItemKind::Fn(sig, generics, body_id) |
416331ca XL |
299 | }) |
300 | } | |
487cf647 | 301 | ItemKind::Mod(_, mod_kind) => match mod_kind { |
04454e1e FG |
302 | ModKind::Loaded(items, _, spans) => { |
303 | hir::ItemKind::Mod(self.lower_mod(items, spans)) | |
6a06907d XL |
304 | } |
305 | ModKind::Unloaded => panic!("`mod` items should have been loaded by now"), | |
306 | }, | |
487cf647 | 307 | ItemKind::ForeignMod(fm) => hir::ItemKind::ForeignMod { |
94222f64 XL |
308 | abi: fm.abi.map_or(abi::Abi::FALLBACK, |abi| self.lower_abi(abi)), |
309 | items: self | |
310 | .arena | |
311 | .alloc_from_iter(fm.items.iter().map(|x| self.lower_foreign_item_ref(x))), | |
312 | }, | |
487cf647 | 313 | ItemKind::GlobalAsm(asm) => hir::ItemKind::GlobalAsm(self.lower_inline_asm(span, asm)), |
9ffffee4 | 314 | ItemKind::TyAlias(box TyAlias { generics, where_clauses, ty, .. }) => { |
f035d41b XL |
315 | // We lower |
316 | // | |
317 | // type Foo = impl Trait | |
318 | // | |
319 | // to | |
320 | // | |
321 | // type Foo = Foo1 | |
322 | // opaque type Foo1: Trait | |
5e7ed085 | 323 | let mut generics = generics.clone(); |
487cf647 | 324 | add_ty_alias_where_clause(&mut generics, *where_clauses, true); |
923072b8 | 325 | let (generics, ty) = self.lower_generics( |
5e7ed085 | 326 | &generics, |
fe692bf9 | 327 | Const::No, |
923072b8 | 328 | id, |
f2b60f7d | 329 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
9ffffee4 FG |
330 | |this| match ty { |
331 | None => { | |
332 | let guar = this.tcx.sess.delay_span_bug( | |
333 | span, | |
334 | "expected to lower type alias type, but it was missing", | |
335 | ); | |
336 | this.arena.alloc(this.ty(span, hir::TyKind::Err(guar))) | |
337 | } | |
49aad941 FG |
338 | Some(ty) => this.lower_ty( |
339 | ty, | |
340 | &ImplTraitContext::TypeAliasesOpaqueTy { in_assoc_ty: false }, | |
341 | ), | |
9ffffee4 | 342 | }, |
5099ac24 | 343 | ); |
74b04a01 XL |
344 | hir::ItemKind::TyAlias(ty, generics) |
345 | } | |
487cf647 | 346 | ItemKind::Enum(enum_definition, generics) => { |
923072b8 | 347 | let (generics, variants) = self.lower_generics( |
5099ac24 | 348 | generics, |
fe692bf9 | 349 | Const::No, |
923072b8 | 350 | id, |
f2b60f7d | 351 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
923072b8 FG |
352 | |this| { |
353 | this.arena.alloc_from_iter( | |
354 | enum_definition.variants.iter().map(|x| this.lower_variant(x)), | |
355 | ) | |
356 | }, | |
357 | ); | |
358 | hir::ItemKind::Enum(hir::EnumDef { variants }, generics) | |
359 | } | |
487cf647 | 360 | ItemKind::Struct(struct_def, generics) => { |
923072b8 FG |
361 | let (generics, struct_def) = self.lower_generics( |
362 | generics, | |
fe692bf9 | 363 | Const::No, |
923072b8 | 364 | id, |
f2b60f7d | 365 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
923072b8 FG |
366 | |this| this.lower_variant_data(hir_id, struct_def), |
367 | ); | |
368 | hir::ItemKind::Struct(struct_def, generics) | |
416331ca | 369 | } |
487cf647 | 370 | ItemKind::Union(vdata, generics) => { |
923072b8 FG |
371 | let (generics, vdata) = self.lower_generics( |
372 | generics, | |
fe692bf9 | 373 | Const::No, |
923072b8 | 374 | id, |
f2b60f7d | 375 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
923072b8 FG |
376 | |this| this.lower_variant_data(hir_id, vdata), |
377 | ); | |
378 | hir::ItemKind::Union(vdata, generics) | |
416331ca | 379 | } |
3c0e092e | 380 | ItemKind::Impl(box Impl { |
416331ca XL |
381 | unsafety, |
382 | polarity, | |
383 | defaultness, | |
dfeec247 | 384 | constness, |
487cf647 FG |
385 | generics: ast_generics, |
386 | of_trait: trait_ref, | |
387 | self_ty: ty, | |
388 | items: impl_items, | |
5869c6ff | 389 | }) => { |
416331ca XL |
390 | // Lower the "impl header" first. This ordering is important |
391 | // for in-band lifetimes! Consider `'a` here: | |
392 | // | |
393 | // impl Foo<'a> for u32 { | |
394 | // fn method(&'a self) { .. } | |
395 | // } | |
396 | // | |
397 | // Because we start by lowering the `Foo<'a> for u32` | |
398 | // part, we will add `'a` to the list of generics on | |
399 | // the impl. When we then encounter it later in the | |
400 | // method, it will not be considered an in-band | |
401 | // lifetime to be added, but rather a reference to a | |
402 | // parent lifetime. | |
9c376795 | 403 | let itctx = ImplTraitContext::Universal; |
04454e1e | 404 | let (generics, (trait_ref, lowered_ty)) = |
fe692bf9 | 405 | self.lower_generics(ast_generics, *constness, id, &itctx, |this| { |
416331ca | 406 | let trait_ref = trait_ref.as_ref().map(|trait_ref| { |
5099ac24 | 407 | this.lower_trait_ref( |
add651ee | 408 | *constness, |
5099ac24 | 409 | trait_ref, |
f2b60f7d | 410 | &ImplTraitContext::Disallowed(ImplTraitPosition::Trait), |
5099ac24 | 411 | ) |
416331ca XL |
412 | }); |
413 | ||
9ffffee4 FG |
414 | let lowered_ty = this.lower_ty( |
415 | ty, | |
416 | &ImplTraitContext::Disallowed(ImplTraitPosition::ImplSelf), | |
417 | ); | |
416331ca XL |
418 | |
419 | (trait_ref, lowered_ty) | |
dfeec247 | 420 | }); |
416331ca | 421 | |
04454e1e FG |
422 | let new_impl_items = self |
423 | .arena | |
424 | .alloc_from_iter(impl_items.iter().map(|item| self.lower_impl_item_ref(item))); | |
425 | ||
ba9703b0 XL |
426 | // `defaultness.has_value()` is never called for an `impl`, always `true` in order |
427 | // to not cause an assertion failure inside the `lower_defaultness` function. | |
428 | let has_val = true; | |
487cf647 | 429 | let (defaultness, defaultness_span) = self.lower_defaultness(*defaultness, has_val); |
94222f64 XL |
430 | let polarity = match polarity { |
431 | ImplPolarity::Positive => ImplPolarity::Positive, | |
487cf647 | 432 | ImplPolarity::Negative(s) => ImplPolarity::Negative(self.lower_span(*s)), |
94222f64 | 433 | }; |
04454e1e | 434 | hir::ItemKind::Impl(self.arena.alloc(hir::Impl { |
487cf647 | 435 | unsafety: self.lower_unsafety(*unsafety), |
60c5eb7d | 436 | polarity, |
ba9703b0 XL |
437 | defaultness, |
438 | defaultness_span, | |
416331ca | 439 | generics, |
dfeec247 XL |
440 | of_trait: trait_ref, |
441 | self_ty: lowered_ty, | |
442 | items: new_impl_items, | |
04454e1e | 443 | })) |
416331ca | 444 | } |
487cf647 | 445 | ItemKind::Trait(box Trait { is_auto, unsafety, generics, bounds, items }) => { |
fe692bf9 FG |
446 | // FIXME(const_trait_impl, effects, fee1-dead) this should be simplified if possible |
447 | let constness = attrs | |
448 | .unwrap_or(&[]) | |
449 | .iter() | |
450 | .find(|x| x.has_name(sym::const_trait)) | |
451 | .map_or(Const::No, |x| Const::Yes(x.span)); | |
923072b8 FG |
452 | let (generics, (unsafety, items, bounds)) = self.lower_generics( |
453 | generics, | |
fe692bf9 | 454 | constness, |
923072b8 | 455 | id, |
f2b60f7d | 456 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
923072b8 FG |
457 | |this| { |
458 | let bounds = this.lower_param_bounds( | |
459 | bounds, | |
f2b60f7d | 460 | &ImplTraitContext::Disallowed(ImplTraitPosition::Bound), |
923072b8 FG |
461 | ); |
462 | let items = this.arena.alloc_from_iter( | |
463 | items.iter().map(|item| this.lower_trait_item_ref(item)), | |
464 | ); | |
487cf647 | 465 | let unsafety = this.lower_unsafety(*unsafety); |
923072b8 FG |
466 | (unsafety, items, bounds) |
467 | }, | |
5099ac24 | 468 | ); |
487cf647 | 469 | hir::ItemKind::Trait(*is_auto, unsafety, generics, bounds, items) |
416331ca | 470 | } |
487cf647 | 471 | ItemKind::TraitAlias(generics, bounds) => { |
923072b8 | 472 | let (generics, bounds) = self.lower_generics( |
5099ac24 | 473 | generics, |
fe692bf9 | 474 | Const::No, |
923072b8 | 475 | id, |
f2b60f7d | 476 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
923072b8 FG |
477 | |this| { |
478 | this.lower_param_bounds( | |
479 | bounds, | |
f2b60f7d | 480 | &ImplTraitContext::Disallowed(ImplTraitPosition::Bound), |
923072b8 FG |
481 | ) |
482 | }, | |
483 | ); | |
484 | hir::ItemKind::TraitAlias(generics, bounds) | |
485 | } | |
487cf647 FG |
486 | ItemKind::MacroDef(MacroDef { body, macro_rules }) => { |
487 | let body = P(self.lower_delim_args(body)); | |
923072b8 | 488 | let macro_kind = self.resolver.decl_macro_kind(self.local_def_id(id)); |
49aad941 FG |
489 | let macro_def = self.arena.alloc(ast::MacroDef { body, macro_rules: *macro_rules }); |
490 | hir::ItemKind::Macro(macro_def, macro_kind) | |
94222f64 XL |
491 | } |
492 | ItemKind::MacCall(..) => { | |
ba9703b0 | 493 | panic!("`TyMac` should have been expanded by now") |
dfeec247 | 494 | } |
416331ca | 495 | } |
416331ca XL |
496 | } |
497 | ||
74b04a01 XL |
498 | fn lower_const_item( |
499 | &mut self, | |
500 | ty: &Ty, | |
501 | span: Span, | |
502 | body: Option<&Expr>, | |
503 | ) -> (&'hir hir::Ty<'hir>, hir::BodyId) { | |
9ffffee4 | 504 | let ty = self.lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::ConstTy)); |
74b04a01 XL |
505 | (ty, self.lower_const_body(span, body)) |
506 | } | |
507 | ||
923072b8 | 508 | #[instrument(level = "debug", skip(self))] |
416331ca XL |
509 | fn lower_use_tree( |
510 | &mut self, | |
511 | tree: &UseTree, | |
512 | prefix: &Path, | |
513 | id: NodeId, | |
04454e1e | 514 | vis_span: Span, |
416331ca | 515 | ident: &mut Ident, |
6a06907d | 516 | attrs: Option<&'hir [Attribute]>, |
dfeec247 | 517 | ) -> hir::ItemKind<'hir> { |
416331ca | 518 | let path = &tree.prefix; |
dfeec247 | 519 | let segments = prefix.segments.iter().chain(path.segments.iter()).cloned().collect(); |
416331ca XL |
520 | |
521 | match tree.kind { | |
487cf647 | 522 | UseTreeKind::Simple(rename) => { |
416331ca XL |
523 | *ident = tree.ident(); |
524 | ||
525 | // First, apply the prefix to the path. | |
1b1a35ee | 526 | let mut path = Path { segments, span: path.span, tokens: None }; |
416331ca XL |
527 | |
528 | // Correctly resolve `self` imports. | |
529 | if path.segments.len() > 1 | |
530 | && path.segments.last().unwrap().ident.name == kw::SelfLower | |
531 | { | |
532 | let _ = path.segments.pop(); | |
533 | if rename.is_none() { | |
534 | *ident = path.segments.last().unwrap().ident; | |
535 | } | |
536 | } | |
537 | ||
487cf647 FG |
538 | let res = |
539 | self.expect_full_res_from_use(id).map(|res| self.lower_res(res)).collect(); | |
540 | let path = self.lower_use_path(res, &path, ParamMode::Explicit); | |
416331ca XL |
541 | hir::ItemKind::Use(path, hir::UseKind::Single) |
542 | } | |
543 | UseTreeKind::Glob => { | |
487cf647 FG |
544 | let res = self.expect_full_res(id); |
545 | let res = smallvec![self.lower_res(res)]; | |
546 | let path = Path { segments, span: path.span, tokens: None }; | |
547 | let path = self.lower_use_path(res, &path, ParamMode::Explicit); | |
416331ca XL |
548 | hir::ItemKind::Use(path, hir::UseKind::Glob) |
549 | } | |
550 | UseTreeKind::Nested(ref trees) => { | |
551 | // Nested imports are desugared into simple imports. | |
552 | // So, if we start with | |
553 | // | |
554 | // ``` | |
555 | // pub(x) use foo::{a, b}; | |
556 | // ``` | |
557 | // | |
558 | // we will create three items: | |
559 | // | |
560 | // ``` | |
561 | // pub(x) use foo::a; | |
562 | // pub(x) use foo::b; | |
563 | // pub(x) use foo::{}; // <-- this is called the `ListStem` | |
564 | // ``` | |
565 | // | |
566 | // The first two are produced by recursively invoking | |
567 | // `lower_use_tree` (and indeed there may be things | |
9c376795 | 568 | // like `use foo::{a::{b, c}}` and so forth). They |
416331ca XL |
569 | // wind up being directly added to |
570 | // `self.items`. However, the structure of this | |
571 | // function also requires us to return one item, and | |
572 | // for that we return the `{}` import (called the | |
573 | // `ListStem`). | |
574 | ||
1b1a35ee | 575 | let prefix = Path { segments, span: prefix.span.to(path.span), tokens: None }; |
416331ca XL |
576 | |
577 | // Add all the nested `PathListItem`s to the HIR. | |
578 | for &(ref use_tree, id) in trees { | |
923072b8 | 579 | let new_hir_id = self.local_def_id(id); |
416331ca | 580 | |
416331ca XL |
581 | // Each `use` import is an item and thus are owners of the |
582 | // names in the path. Up to this point the nested import is | |
583 | // the current owner, since we want each desugared import to | |
584 | // own its own names, we have to adjust the owner before | |
585 | // lowering the rest of the import. | |
586 | self.with_hir_id_owner(id, |this| { | |
416331ca XL |
587 | let mut ident = *ident; |
588 | ||
add651ee FG |
589 | // `prefix` is lowered multiple times, but in different HIR owners. |
590 | // So each segment gets renewed `HirId` with the same | |
591 | // `ItemLocalId` and the new owner. (See `lower_node_id`) | |
dfeec247 | 592 | let kind = |
04454e1e | 593 | this.lower_use_tree(use_tree, &prefix, id, vis_span, &mut ident, attrs); |
6a06907d | 594 | if let Some(attrs) = attrs { |
3c0e092e | 595 | this.attrs.insert(hir::ItemLocalId::new(0), attrs); |
6a06907d | 596 | } |
dfeec247 | 597 | |
c295e0f8 | 598 | let item = hir::Item { |
2b03887a | 599 | owner_id: hir::OwnerId { def_id: new_hir_id }, |
94222f64 | 600 | ident: this.lower_ident(ident), |
dfeec247 | 601 | kind, |
04454e1e | 602 | vis_span, |
94222f64 | 603 | span: this.lower_span(use_tree.span), |
c295e0f8 XL |
604 | }; |
605 | hir::OwnerNode::Item(this.arena.alloc(item)) | |
416331ca XL |
606 | }); |
607 | } | |
608 | ||
487cf647 FG |
609 | let res = |
610 | self.expect_full_res_from_use(id).map(|res| self.lower_res(res)).collect(); | |
611 | let path = self.lower_use_path(res, &prefix, ParamMode::Explicit); | |
416331ca XL |
612 | hir::ItemKind::Use(path, hir::UseKind::ListStem) |
613 | } | |
614 | } | |
615 | } | |
616 | ||
c295e0f8 | 617 | fn lower_foreign_item(&mut self, i: &ForeignItem) -> &'hir hir::ForeignItem<'hir> { |
6a06907d | 618 | let hir_id = self.lower_node_id(i.id); |
2b03887a | 619 | let owner_id = hir_id.expect_owner(); |
6a06907d | 620 | self.lower_attrs(hir_id, &i.attrs); |
c295e0f8 | 621 | let item = hir::ForeignItem { |
2b03887a | 622 | owner_id, |
94222f64 | 623 | ident: self.lower_ident(i.ident), |
487cf647 FG |
624 | kind: match &i.kind { |
625 | ForeignItemKind::Fn(box Fn { sig, generics, .. }) => { | |
74b04a01 | 626 | let fdec = &sig.decl; |
9c376795 | 627 | let itctx = ImplTraitContext::Universal; |
04454e1e | 628 | let (generics, (fn_dec, fn_args)) = |
fe692bf9 | 629 | self.lower_generics(generics, Const::No, i.id, &itctx, |this| { |
416331ca | 630 | ( |
e1599b0c | 631 | // Disallow `impl Trait` in foreign items. |
f2b60f7d FG |
632 | this.lower_fn_decl( |
633 | fdec, | |
487cf647 | 634 | i.id, |
f2b60f7d FG |
635 | sig.span, |
636 | FnDeclKind::ExternFn, | |
637 | None, | |
638 | ), | |
e1599b0c | 639 | this.lower_fn_params_to_names(fdec), |
416331ca | 640 | ) |
04454e1e | 641 | }); |
416331ca XL |
642 | |
643 | hir::ForeignItemKind::Fn(fn_dec, fn_args, generics) | |
644 | } | |
487cf647 | 645 | ForeignItemKind::Static(t, m, _) => { |
9ffffee4 FG |
646 | let ty = self |
647 | .lower_ty(t, &ImplTraitContext::Disallowed(ImplTraitPosition::StaticTy)); | |
487cf647 | 648 | hir::ForeignItemKind::Static(ty, *m) |
416331ca | 649 | } |
74b04a01 | 650 | ForeignItemKind::TyAlias(..) => hir::ForeignItemKind::Type, |
ba9703b0 | 651 | ForeignItemKind::MacCall(_) => panic!("macro shouldn't exist here"), |
416331ca | 652 | }, |
04454e1e | 653 | vis_span: self.lower_span(i.vis.span), |
94222f64 | 654 | span: self.lower_span(i.span), |
c295e0f8 XL |
655 | }; |
656 | self.arena.alloc(item) | |
416331ca XL |
657 | } |
658 | ||
c295e0f8 | 659 | fn lower_foreign_item_ref(&mut self, i: &ForeignItem) -> hir::ForeignItemRef { |
fc512014 | 660 | hir::ForeignItemRef { |
2b03887a | 661 | id: hir::ForeignItemId { owner_id: hir::OwnerId { def_id: self.local_def_id(i.id) } }, |
94222f64 XL |
662 | ident: self.lower_ident(i.ident), |
663 | span: self.lower_span(i.span), | |
416331ca XL |
664 | } |
665 | } | |
666 | ||
dfeec247 | 667 | fn lower_variant(&mut self, v: &Variant) -> hir::Variant<'hir> { |
487cf647 FG |
668 | let hir_id = self.lower_node_id(v.id); |
669 | self.lower_attrs(hir_id, &v.attrs); | |
e1599b0c | 670 | hir::Variant { |
487cf647 FG |
671 | hir_id, |
672 | def_id: self.local_def_id(v.id), | |
673 | data: self.lower_variant_data(hir_id, &v.data), | |
e1599b0c | 674 | disr_expr: v.disr_expr.as_ref().map(|e| self.lower_anon_const(e)), |
94222f64 XL |
675 | ident: self.lower_ident(v.ident), |
676 | span: self.lower_span(v.span), | |
416331ca XL |
677 | } |
678 | } | |
679 | ||
6a06907d XL |
680 | fn lower_variant_data( |
681 | &mut self, | |
682 | parent_id: hir::HirId, | |
683 | vdata: &VariantData, | |
684 | ) -> hir::VariantData<'hir> { | |
487cf647 FG |
685 | match vdata { |
686 | VariantData::Struct(fields, recovered) => hir::VariantData::Struct( | |
dfeec247 | 687 | self.arena |
6a06907d | 688 | .alloc_from_iter(fields.iter().enumerate().map(|f| self.lower_field_def(f))), |
487cf647 | 689 | *recovered, |
416331ca | 690 | ), |
487cf647 FG |
691 | VariantData::Tuple(fields, id) => { |
692 | let ctor_id = self.lower_node_id(*id); | |
6a06907d XL |
693 | self.alias_attrs(ctor_id, parent_id); |
694 | hir::VariantData::Tuple( | |
695 | self.arena.alloc_from_iter( | |
696 | fields.iter().enumerate().map(|f| self.lower_field_def(f)), | |
697 | ), | |
698 | ctor_id, | |
487cf647 | 699 | self.local_def_id(*id), |
6a06907d XL |
700 | ) |
701 | } | |
702 | VariantData::Unit(id) => { | |
487cf647 | 703 | let ctor_id = self.lower_node_id(*id); |
6a06907d | 704 | self.alias_attrs(ctor_id, parent_id); |
487cf647 | 705 | hir::VariantData::Unit(ctor_id, self.local_def_id(*id)) |
6a06907d | 706 | } |
416331ca XL |
707 | } |
708 | } | |
709 | ||
94222f64 | 710 | fn lower_field_def(&mut self, (index, f): (usize, &FieldDef)) -> hir::FieldDef<'hir> { |
487cf647 | 711 | let ty = if let TyKind::Path(qself, path) = &f.ty.kind { |
416331ca XL |
712 | let t = self.lower_path_ty( |
713 | &f.ty, | |
714 | qself, | |
715 | path, | |
716 | ParamMode::ExplicitNamed, // no `'_` in declarations (Issue #61124) | |
9ffffee4 | 717 | &ImplTraitContext::Disallowed(ImplTraitPosition::FieldTy), |
416331ca | 718 | ); |
dfeec247 | 719 | self.arena.alloc(t) |
416331ca | 720 | } else { |
9ffffee4 | 721 | self.lower_ty(&f.ty, &ImplTraitContext::Disallowed(ImplTraitPosition::FieldTy)) |
416331ca | 722 | }; |
6a06907d XL |
723 | let hir_id = self.lower_node_id(f.id); |
724 | self.lower_attrs(hir_id, &f.attrs); | |
725 | hir::FieldDef { | |
94222f64 | 726 | span: self.lower_span(f.span), |
6a06907d | 727 | hir_id, |
487cf647 | 728 | def_id: self.local_def_id(f.id), |
416331ca | 729 | ident: match f.ident { |
94222f64 | 730 | Some(ident) => self.lower_ident(ident), |
416331ca | 731 | // FIXME(jseyfried): positional field hygiene. |
94222f64 | 732 | None => Ident::new(sym::integer(index), self.lower_span(f.span)), |
416331ca | 733 | }, |
04454e1e | 734 | vis_span: self.lower_span(f.vis.span), |
416331ca | 735 | ty, |
416331ca XL |
736 | } |
737 | } | |
738 | ||
c295e0f8 | 739 | fn lower_trait_item(&mut self, i: &AssocItem) -> &'hir hir::TraitItem<'hir> { |
6a06907d | 740 | let hir_id = self.lower_node_id(i.id); |
487cf647 | 741 | self.lower_attrs(hir_id, &i.attrs); |
6a06907d | 742 | let trait_item_def_id = hir_id.expect_owner(); |
416331ca | 743 | |
487cf647 | 744 | let (generics, kind, has_default) = match &i.kind { |
add651ee FG |
745 | AssocItemKind::Const(box ConstItem { generics, ty, expr, .. }) => { |
746 | let (generics, kind) = self.lower_generics( | |
747 | &generics, | |
748 | Const::No, | |
749 | i.id, | |
750 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), | |
751 | |this| { | |
752 | let ty = this.lower_ty( | |
753 | ty, | |
754 | &ImplTraitContext::Disallowed(ImplTraitPosition::ConstTy), | |
755 | ); | |
756 | let body = expr.as_ref().map(|x| this.lower_const_body(i.span, Some(x))); | |
757 | ||
758 | hir::TraitItemKind::Const(ty, body) | |
759 | }, | |
760 | ); | |
761 | (generics, kind, expr.is_some()) | |
dfeec247 | 762 | } |
487cf647 | 763 | AssocItemKind::Fn(box Fn { sig, generics, body: None, .. }) => { |
f2b60f7d | 764 | let asyncness = sig.header.asyncness; |
e1599b0c | 765 | let names = self.lower_fn_params_to_names(&sig.decl); |
f2b60f7d FG |
766 | let (generics, sig) = self.lower_method_sig( |
767 | generics, | |
768 | sig, | |
769 | i.id, | |
770 | FnDeclKind::Trait, | |
771 | asyncness.opt_return_id(), | |
772 | ); | |
064997fb | 773 | (generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Required(names)), false) |
416331ca | 774 | } |
487cf647 | 775 | AssocItemKind::Fn(box Fn { sig, generics, body: Some(body), .. }) => { |
cdc7bbd5 XL |
776 | let asyncness = sig.header.asyncness; |
777 | let body_id = | |
487cf647 | 778 | self.lower_maybe_async_body(i.span, hir_id, &sig.decl, asyncness, Some(&body)); |
cdc7bbd5 XL |
779 | let (generics, sig) = self.lower_method_sig( |
780 | generics, | |
781 | sig, | |
04454e1e | 782 | i.id, |
5099ac24 | 783 | FnDeclKind::Trait, |
cdc7bbd5 | 784 | asyncness.opt_return_id(), |
cdc7bbd5 | 785 | ); |
064997fb | 786 | (generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Provided(body_id)), true) |
416331ca | 787 | } |
487cf647 | 788 | AssocItemKind::Type(box TyAlias { generics, where_clauses, bounds, ty, .. }) => { |
5e7ed085 | 789 | let mut generics = generics.clone(); |
487cf647 | 790 | add_ty_alias_where_clause(&mut generics, *where_clauses, false); |
064997fb | 791 | let (generics, kind) = self.lower_generics( |
5e7ed085 | 792 | &generics, |
fe692bf9 | 793 | Const::No, |
923072b8 | 794 | i.id, |
f2b60f7d | 795 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
923072b8 FG |
796 | |this| { |
797 | let ty = ty.as_ref().map(|x| { | |
9ffffee4 FG |
798 | this.lower_ty( |
799 | x, | |
800 | &ImplTraitContext::Disallowed(ImplTraitPosition::AssocTy), | |
801 | ) | |
923072b8 FG |
802 | }); |
803 | hir::TraitItemKind::Type( | |
804 | this.lower_param_bounds( | |
805 | bounds, | |
f2b60f7d | 806 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
923072b8 FG |
807 | ), |
808 | ty, | |
809 | ) | |
810 | }, | |
064997fb FG |
811 | ); |
812 | (generics, kind, ty.is_some()) | |
dfeec247 | 813 | } |
ba9703b0 | 814 | AssocItemKind::MacCall(..) => panic!("macro item shouldn't exist at this point"), |
416331ca XL |
815 | }; |
816 | ||
c295e0f8 | 817 | let item = hir::TraitItem { |
2b03887a | 818 | owner_id: trait_item_def_id, |
94222f64 XL |
819 | ident: self.lower_ident(i.ident), |
820 | generics, | |
821 | kind, | |
822 | span: self.lower_span(i.span), | |
064997fb | 823 | defaultness: hir::Defaultness::Default { has_value: has_default }, |
c295e0f8 XL |
824 | }; |
825 | self.arena.alloc(item) | |
416331ca XL |
826 | } |
827 | ||
dfeec247 | 828 | fn lower_trait_item_ref(&mut self, i: &AssocItem) -> hir::TraitItemRef { |
064997fb FG |
829 | let kind = match &i.kind { |
830 | AssocItemKind::Const(..) => hir::AssocItemKind::Const, | |
2b03887a | 831 | AssocItemKind::Type(..) => hir::AssocItemKind::Type, |
064997fb FG |
832 | AssocItemKind::Fn(box Fn { sig, .. }) => { |
833 | hir::AssocItemKind::Fn { has_self: sig.decl.has_self() } | |
416331ca | 834 | } |
ba9703b0 | 835 | AssocItemKind::MacCall(..) => unimplemented!(), |
416331ca | 836 | }; |
2b03887a | 837 | let id = hir::TraitItemId { owner_id: hir::OwnerId { def_id: self.local_def_id(i.id) } }; |
94222f64 XL |
838 | hir::TraitItemRef { |
839 | id, | |
840 | ident: self.lower_ident(i.ident), | |
841 | span: self.lower_span(i.span), | |
94222f64 XL |
842 | kind, |
843 | } | |
416331ca XL |
844 | } |
845 | ||
dfeec247 | 846 | /// Construct `ExprKind::Err` for the given `span`. |
9ffffee4 FG |
847 | pub(crate) fn expr_err(&mut self, span: Span, guar: ErrorGuaranteed) -> hir::Expr<'hir> { |
848 | self.expr(span, hir::ExprKind::Err(guar)) | |
dfeec247 XL |
849 | } |
850 | ||
c295e0f8 | 851 | fn lower_impl_item(&mut self, i: &AssocItem) -> &'hir hir::ImplItem<'hir> { |
064997fb FG |
852 | // Since `default impl` is not yet implemented, this is always true in impls. |
853 | let has_value = true; | |
854 | let (defaultness, _) = self.lower_defaultness(i.kind.defaultness(), has_value); | |
487cf647 FG |
855 | let hir_id = self.lower_node_id(i.id); |
856 | self.lower_attrs(hir_id, &i.attrs); | |
064997fb | 857 | |
74b04a01 | 858 | let (generics, kind) = match &i.kind { |
add651ee FG |
859 | AssocItemKind::Const(box ConstItem { generics, ty, expr, .. }) => self.lower_generics( |
860 | &generics, | |
861 | Const::No, | |
862 | i.id, | |
863 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), | |
864 | |this| { | |
865 | let ty = this | |
866 | .lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::ConstTy)); | |
867 | let body = this.lower_const_body(i.span, expr.as_deref()); | |
868 | ||
869 | hir::ImplItemKind::Const(ty, body) | |
870 | }, | |
871 | ), | |
3c0e092e | 872 | AssocItemKind::Fn(box Fn { sig, generics, body, .. }) => { |
416331ca | 873 | self.current_item = Some(i.span); |
74b04a01 | 874 | let asyncness = sig.header.asyncness; |
487cf647 FG |
875 | let body_id = self.lower_maybe_async_body( |
876 | i.span, | |
877 | hir_id, | |
878 | &sig.decl, | |
879 | asyncness, | |
880 | body.as_deref(), | |
881 | ); | |
416331ca | 882 | let (generics, sig) = self.lower_method_sig( |
74b04a01 | 883 | generics, |
416331ca | 884 | sig, |
04454e1e | 885 | i.id, |
5099ac24 | 886 | if self.is_in_trait_impl { FnDeclKind::Impl } else { FnDeclKind::Inherent }, |
74b04a01 | 887 | asyncness.opt_return_id(), |
416331ca XL |
888 | ); |
889 | ||
ba9703b0 | 890 | (generics, hir::ImplItemKind::Fn(sig, body_id)) |
416331ca | 891 | } |
2b03887a | 892 | AssocItemKind::Type(box TyAlias { generics, where_clauses, ty, .. }) => { |
5e7ed085 FG |
893 | let mut generics = generics.clone(); |
894 | add_ty_alias_where_clause(&mut generics, *where_clauses, false); | |
923072b8 | 895 | self.lower_generics( |
5e7ed085 | 896 | &generics, |
fe692bf9 | 897 | Const::No, |
923072b8 | 898 | i.id, |
f2b60f7d | 899 | &ImplTraitContext::Disallowed(ImplTraitPosition::Generic), |
923072b8 FG |
900 | |this| match ty { |
901 | None => { | |
9ffffee4 FG |
902 | let guar = this.tcx.sess.delay_span_bug( |
903 | i.span, | |
904 | "expected to lower associated type, but it was missing", | |
905 | ); | |
906 | let ty = this.arena.alloc(this.ty(i.span, hir::TyKind::Err(guar))); | |
2b03887a | 907 | hir::ImplItemKind::Type(ty) |
923072b8 FG |
908 | } |
909 | Some(ty) => { | |
49aad941 FG |
910 | let ty = this.lower_ty( |
911 | ty, | |
912 | &ImplTraitContext::TypeAliasesOpaqueTy { in_assoc_ty: true }, | |
913 | ); | |
2b03887a | 914 | hir::ImplItemKind::Type(ty) |
923072b8 FG |
915 | } |
916 | }, | |
917 | ) | |
dfeec247 | 918 | } |
ba9703b0 | 919 | AssocItemKind::MacCall(..) => panic!("`TyMac` should have been expanded by now"), |
416331ca XL |
920 | }; |
921 | ||
c295e0f8 | 922 | let item = hir::ImplItem { |
2b03887a | 923 | owner_id: hir_id.expect_owner(), |
94222f64 | 924 | ident: self.lower_ident(i.ident), |
416331ca | 925 | generics, |
e74abb32 | 926 | kind, |
04454e1e | 927 | vis_span: self.lower_span(i.vis.span), |
94222f64 | 928 | span: self.lower_span(i.span), |
064997fb | 929 | defaultness, |
c295e0f8 XL |
930 | }; |
931 | self.arena.alloc(item) | |
416331ca XL |
932 | } |
933 | ||
c295e0f8 | 934 | fn lower_impl_item_ref(&mut self, i: &AssocItem) -> hir::ImplItemRef { |
416331ca | 935 | hir::ImplItemRef { |
2b03887a | 936 | id: hir::ImplItemId { owner_id: hir::OwnerId { def_id: self.local_def_id(i.id) } }, |
94222f64 XL |
937 | ident: self.lower_ident(i.ident), |
938 | span: self.lower_span(i.span), | |
60c5eb7d | 939 | kind: match &i.kind { |
dfeec247 | 940 | AssocItemKind::Const(..) => hir::AssocItemKind::Const, |
2b03887a | 941 | AssocItemKind::Type(..) => hir::AssocItemKind::Type, |
3c0e092e | 942 | AssocItemKind::Fn(box Fn { sig, .. }) => { |
ba9703b0 | 943 | hir::AssocItemKind::Fn { has_self: sig.decl.has_self() } |
dfeec247 | 944 | } |
ba9703b0 | 945 | AssocItemKind::MacCall(..) => unimplemented!(), |
416331ca | 946 | }, |
2b03887a FG |
947 | trait_item_def_id: self |
948 | .resolver | |
949 | .get_partial_res(i.id) | |
950 | .map(|r| r.expect_full_res().def_id()), | |
416331ca | 951 | } |
416331ca XL |
952 | } |
953 | ||
ba9703b0 XL |
954 | fn lower_defaultness( |
955 | &self, | |
956 | d: Defaultness, | |
957 | has_value: bool, | |
958 | ) -> (hir::Defaultness, Option<Span>) { | |
416331ca | 959 | match d { |
94222f64 XL |
960 | Defaultness::Default(sp) => { |
961 | (hir::Defaultness::Default { has_value }, Some(self.lower_span(sp))) | |
962 | } | |
416331ca XL |
963 | Defaultness::Final => { |
964 | assert!(has_value); | |
ba9703b0 | 965 | (hir::Defaultness::Final, None) |
416331ca XL |
966 | } |
967 | } | |
968 | } | |
969 | ||
dfeec247 XL |
970 | fn record_body( |
971 | &mut self, | |
972 | params: &'hir [hir::Param<'hir>], | |
973 | value: hir::Expr<'hir>, | |
974 | ) -> hir::BodyId { | |
f2b60f7d | 975 | let body = hir::Body { |
ed00b5ec | 976 | coroutine_kind: self.coroutine_kind, |
f2b60f7d FG |
977 | params, |
978 | value: self.arena.alloc(value), | |
979 | }; | |
416331ca | 980 | let id = body.id(); |
3c0e092e XL |
981 | debug_assert_eq!(id.hir_id.owner, self.current_hir_id_owner); |
982 | self.bodies.push((id.hir_id.local_id, self.arena.alloc(body))); | |
416331ca XL |
983 | id |
984 | } | |
985 | ||
ba9703b0 | 986 | pub(super) fn lower_body( |
416331ca | 987 | &mut self, |
dfeec247 | 988 | f: impl FnOnce(&mut Self) -> (&'hir [hir::Param<'hir>], hir::Expr<'hir>), |
416331ca | 989 | ) -> hir::BodyId { |
ed00b5ec | 990 | let prev_coroutine_kind = self.coroutine_kind.take(); |
ba9703b0 | 991 | let task_context = self.task_context.take(); |
e1599b0c XL |
992 | let (parameters, result) = f(self); |
993 | let body_id = self.record_body(parameters, result); | |
ba9703b0 | 994 | self.task_context = task_context; |
ed00b5ec | 995 | self.coroutine_kind = prev_coroutine_kind; |
416331ca XL |
996 | body_id |
997 | } | |
998 | ||
dfeec247 | 999 | fn lower_param(&mut self, param: &Param) -> hir::Param<'hir> { |
6a06907d XL |
1000 | let hir_id = self.lower_node_id(param.id); |
1001 | self.lower_attrs(hir_id, ¶m.attrs); | |
e1599b0c | 1002 | hir::Param { |
6a06907d | 1003 | hir_id, |
e1599b0c | 1004 | pat: self.lower_pat(¶m.pat), |
94222f64 XL |
1005 | ty_span: self.lower_span(param.ty.span), |
1006 | span: self.lower_span(param.span), | |
416331ca XL |
1007 | } |
1008 | } | |
1009 | ||
1010 | pub(super) fn lower_fn_body( | |
1011 | &mut self, | |
1012 | decl: &FnDecl, | |
dfeec247 | 1013 | body: impl FnOnce(&mut Self) -> hir::Expr<'hir>, |
416331ca | 1014 | ) -> hir::BodyId { |
dfeec247 XL |
1015 | self.lower_body(|this| { |
1016 | ( | |
1017 | this.arena.alloc_from_iter(decl.inputs.iter().map(|x| this.lower_param(x))), | |
1018 | body(this), | |
1019 | ) | |
1020 | }) | |
416331ca XL |
1021 | } |
1022 | ||
dfeec247 XL |
1023 | fn lower_fn_body_block( |
1024 | &mut self, | |
1025 | span: Span, | |
1026 | decl: &FnDecl, | |
1027 | body: Option<&Block>, | |
1028 | ) -> hir::BodyId { | |
1029 | self.lower_fn_body(decl, |this| this.lower_block_expr_opt(span, body)) | |
416331ca XL |
1030 | } |
1031 | ||
dfeec247 XL |
1032 | fn lower_block_expr_opt(&mut self, span: Span, block: Option<&Block>) -> hir::Expr<'hir> { |
1033 | match block { | |
1034 | Some(block) => self.lower_block_expr(block), | |
9ffffee4 | 1035 | None => self.expr_err(span, self.tcx.sess.delay_span_bug(span, "no block")), |
dfeec247 XL |
1036 | } |
1037 | } | |
1038 | ||
1039 | pub(super) fn lower_const_body(&mut self, span: Span, expr: Option<&Expr>) -> hir::BodyId { | |
1040 | self.lower_body(|this| { | |
1041 | ( | |
1042 | &[], | |
1043 | match expr { | |
1044 | Some(expr) => this.lower_expr_mut(expr), | |
9ffffee4 | 1045 | None => this.expr_err(span, this.tcx.sess.delay_span_bug(span, "no block")), |
dfeec247 XL |
1046 | }, |
1047 | ) | |
1048 | }) | |
416331ca XL |
1049 | } |
1050 | ||
1051 | fn lower_maybe_async_body( | |
1052 | &mut self, | |
dfeec247 | 1053 | span: Span, |
487cf647 | 1054 | fn_id: hir::HirId, |
416331ca | 1055 | decl: &FnDecl, |
74b04a01 | 1056 | asyncness: Async, |
dfeec247 | 1057 | body: Option<&Block>, |
416331ca | 1058 | ) -> hir::BodyId { |
2b03887a FG |
1059 | let (closure_id, body) = match (asyncness, body) { |
1060 | (Async::Yes { closure_id, .. }, Some(body)) => (closure_id, body), | |
1061 | _ => return self.lower_fn_body_block(span, decl, body), | |
416331ca XL |
1062 | }; |
1063 | ||
1064 | self.lower_body(|this| { | |
dfeec247 XL |
1065 | let mut parameters: Vec<hir::Param<'_>> = Vec::new(); |
1066 | let mut statements: Vec<hir::Stmt<'_>> = Vec::new(); | |
416331ca | 1067 | |
e1599b0c | 1068 | // Async function parameters are lowered into the closure body so that they are |
416331ca XL |
1069 | // captured and so that the drop order matches the equivalent non-async functions. |
1070 | // | |
1071 | // from: | |
1072 | // | |
1073 | // async fn foo(<pattern>: <ty>, <pattern>: <ty>, <pattern>: <ty>) { | |
e1599b0c | 1074 | // <body> |
416331ca XL |
1075 | // } |
1076 | // | |
1077 | // into: | |
1078 | // | |
1079 | // fn foo(__arg0: <ty>, __arg1: <ty>, __arg2: <ty>) { | |
1080 | // async move { | |
1081 | // let __arg2 = __arg2; | |
1082 | // let <pattern> = __arg2; | |
1083 | // let __arg1 = __arg1; | |
1084 | // let <pattern> = __arg1; | |
1085 | // let __arg0 = __arg0; | |
1086 | // let <pattern> = __arg0; | |
e1599b0c | 1087 | // drop-temps { <body> } // see comments later in fn for details |
416331ca XL |
1088 | // } |
1089 | // } | |
1090 | // | |
1091 | // If `<pattern>` is a simple ident, then it is lowered to a single | |
1092 | // `let <pattern> = <pattern>;` statement as an optimization. | |
e1599b0c XL |
1093 | // |
1094 | // Note that the body is embedded in `drop-temps`; an | |
1095 | // equivalent desugaring would be `return { <body> | |
1096 | // };`. The key point is that we wish to drop all the | |
1097 | // let-bound variables and temporaries created in the body | |
1098 | // (and its tail expression!) before we drop the | |
1099 | // parameters (c.f. rust-lang/rust#64512). | |
1100 | for (index, parameter) in decl.inputs.iter().enumerate() { | |
1101 | let parameter = this.lower_param(parameter); | |
1102 | let span = parameter.pat.span; | |
416331ca XL |
1103 | |
1104 | // Check if this is a binding pattern, if so, we can optimize and avoid adding a | |
e1599b0c | 1105 | // `let <pat> = __argN;` statement. In this case, we do not rename the parameter. |
e74abb32 | 1106 | let (ident, is_simple_parameter) = match parameter.pat.kind { |
f2b60f7d FG |
1107 | hir::PatKind::Binding(hir::BindingAnnotation(ByRef::No, _), _, ident, _) => { |
1108 | (ident, true) | |
1109 | } | |
29967ef6 XL |
1110 | // For `ref mut` or wildcard arguments, we can't reuse the binding, but |
1111 | // we can keep the same name for the parameter. | |
1112 | // This lets rustdoc render it correctly in documentation. | |
1113 | hir::PatKind::Binding(_, _, ident, _) => (ident, false), | |
1114 | hir::PatKind::Wild => { | |
1115 | (Ident::with_dummy_span(rustc_span::symbol::kw::Underscore), false) | |
dfeec247 | 1116 | } |
416331ca XL |
1117 | _ => { |
1118 | // Replace the ident for bindings that aren't simple. | |
9c376795 | 1119 | let name = format!("__arg{index}"); |
416331ca XL |
1120 | let ident = Ident::from_str(&name); |
1121 | ||
1122 | (ident, false) | |
dfeec247 | 1123 | } |
416331ca XL |
1124 | }; |
1125 | ||
dfeec247 | 1126 | let desugared_span = this.mark_span_with_reason(DesugaringKind::Async, span, None); |
416331ca | 1127 | |
e1599b0c | 1128 | // Construct a parameter representing `__argN: <ty>` to replace the parameter of the |
416331ca XL |
1129 | // async function. |
1130 | // | |
e1599b0c XL |
1131 | // If this is the simple case, this parameter will end up being the same as the |
1132 | // original parameter, but with a different pattern id. | |
3c0e092e | 1133 | let stmt_attrs = this.attrs.get(¶meter.hir_id.local_id).copied(); |
e1599b0c XL |
1134 | let (new_parameter_pat, new_parameter_id) = this.pat_ident(desugared_span, ident); |
1135 | let new_parameter = hir::Param { | |
e1599b0c XL |
1136 | hir_id: parameter.hir_id, |
1137 | pat: new_parameter_pat, | |
94222f64 XL |
1138 | ty_span: this.lower_span(parameter.ty_span), |
1139 | span: this.lower_span(parameter.span), | |
416331ca XL |
1140 | }; |
1141 | ||
e1599b0c | 1142 | if is_simple_parameter { |
416331ca XL |
1143 | // If this is the simple case, then we only insert one statement that is |
1144 | // `let <pat> = <pat>;`. We re-use the original argument's pattern so that | |
1145 | // `HirId`s are densely assigned. | |
e1599b0c | 1146 | let expr = this.expr_ident(desugared_span, ident, new_parameter_id); |
416331ca XL |
1147 | let stmt = this.stmt_let_pat( |
1148 | stmt_attrs, | |
1149 | desugared_span, | |
dfeec247 | 1150 | Some(expr), |
e1599b0c | 1151 | parameter.pat, |
dfeec247 | 1152 | hir::LocalSource::AsyncFn, |
416331ca XL |
1153 | ); |
1154 | statements.push(stmt); | |
1155 | } else { | |
1156 | // If this is not the simple case, then we construct two statements: | |
1157 | // | |
1158 | // ``` | |
1159 | // let __argN = __argN; | |
1160 | // let <pat> = __argN; | |
1161 | // ``` | |
1162 | // | |
e1599b0c | 1163 | // The first statement moves the parameter into the closure and thus ensures |
416331ca XL |
1164 | // that the drop order is correct. |
1165 | // | |
1166 | // The second statement creates the bindings that the user wrote. | |
1167 | ||
1168 | // Construct the `let mut __argN = __argN;` statement. It must be a mut binding | |
1169 | // because the user may have specified a `ref mut` binding in the next | |
1170 | // statement. | |
1171 | let (move_pat, move_id) = this.pat_ident_binding_mode( | |
dfeec247 XL |
1172 | desugared_span, |
1173 | ident, | |
f2b60f7d | 1174 | hir::BindingAnnotation::MUT, |
dfeec247 | 1175 | ); |
e1599b0c | 1176 | let move_expr = this.expr_ident(desugared_span, ident, new_parameter_id); |
416331ca | 1177 | let move_stmt = this.stmt_let_pat( |
6a06907d | 1178 | None, |
416331ca | 1179 | desugared_span, |
dfeec247 | 1180 | Some(move_expr), |
416331ca | 1181 | move_pat, |
dfeec247 | 1182 | hir::LocalSource::AsyncFn, |
416331ca XL |
1183 | ); |
1184 | ||
1185 | // Construct the `let <pat> = __argN;` statement. We re-use the original | |
e1599b0c | 1186 | // parameter's pattern so that `HirId`s are densely assigned. |
416331ca XL |
1187 | let pattern_expr = this.expr_ident(desugared_span, ident, move_id); |
1188 | let pattern_stmt = this.stmt_let_pat( | |
1189 | stmt_attrs, | |
1190 | desugared_span, | |
dfeec247 | 1191 | Some(pattern_expr), |
e1599b0c | 1192 | parameter.pat, |
dfeec247 | 1193 | hir::LocalSource::AsyncFn, |
416331ca XL |
1194 | ); |
1195 | ||
1196 | statements.push(move_stmt); | |
1197 | statements.push(pattern_stmt); | |
1198 | }; | |
1199 | ||
e1599b0c | 1200 | parameters.push(new_parameter); |
416331ca XL |
1201 | } |
1202 | ||
1203 | let async_expr = this.make_async_expr( | |
ed00b5ec | 1204 | CaptureBy::Value { move_kw: rustc_span::DUMMY_SP }, |
e74abb32 XL |
1205 | closure_id, |
1206 | None, | |
2b03887a | 1207 | body.span, |
ed00b5ec | 1208 | hir::CoroutineSource::Fn, |
416331ca | 1209 | |this| { |
e1599b0c | 1210 | // Create a block from the user's function body: |
2b03887a | 1211 | let user_body = this.lower_block_expr(body); |
e1599b0c XL |
1212 | |
1213 | // Transform into `drop-temps { <user-body> }`, an expression: | |
dfeec247 XL |
1214 | let desugared_span = |
1215 | this.mark_span_with_reason(DesugaringKind::Async, user_body.span, None); | |
487cf647 FG |
1216 | let user_body = |
1217 | this.expr_drop_temps(desugared_span, this.arena.alloc(user_body)); | |
e1599b0c XL |
1218 | |
1219 | // As noted above, create the final block like | |
1220 | // | |
1221 | // ``` | |
1222 | // { | |
1223 | // let $param_pattern = $raw_param; | |
1224 | // ... | |
1225 | // drop-temps { <user-body> } | |
1226 | // } | |
1227 | // ``` | |
1228 | let body = this.block_all( | |
1229 | desugared_span, | |
dfeec247 XL |
1230 | this.arena.alloc_from_iter(statements), |
1231 | Some(user_body), | |
e1599b0c | 1232 | ); |
dfeec247 | 1233 | |
487cf647 | 1234 | this.expr_block(body) |
dfeec247 XL |
1235 | }, |
1236 | ); | |
1237 | ||
353b0b11 FG |
1238 | let hir_id = this.lower_node_id(closure_id); |
1239 | this.maybe_forward_track_caller(body.span, fn_id, hir_id); | |
1240 | let expr = hir::Expr { hir_id, kind: async_expr, span: this.lower_span(body.span) }; | |
1241 | ||
1242 | (this.arena.alloc_from_iter(parameters), expr) | |
416331ca XL |
1243 | }) |
1244 | } | |
1245 | ||
1246 | fn lower_method_sig( | |
1247 | &mut self, | |
1248 | generics: &Generics, | |
60c5eb7d | 1249 | sig: &FnSig, |
04454e1e | 1250 | id: NodeId, |
5099ac24 | 1251 | kind: FnDeclKind, |
f2b60f7d | 1252 | is_async: Option<(NodeId, Span)>, |
04454e1e | 1253 | ) -> (&'hir hir::Generics<'hir>, hir::FnSig<'hir>) { |
94222f64 | 1254 | let header = self.lower_fn_header(sig.header); |
9c376795 | 1255 | let itctx = ImplTraitContext::Universal; |
fe692bf9 FG |
1256 | let (generics, decl) = |
1257 | self.lower_generics(generics, sig.header.constness, id, &itctx, |this| { | |
1258 | this.lower_fn_decl(&sig.decl, id, sig.span, kind, is_async) | |
1259 | }); | |
94222f64 | 1260 | (generics, hir::FnSig { header, decl, span: self.lower_span(sig.span) }) |
416331ca XL |
1261 | } |
1262 | ||
94222f64 | 1263 | fn lower_fn_header(&mut self, h: FnHeader) -> hir::FnHeader { |
416331ca | 1264 | hir::FnHeader { |
74b04a01 XL |
1265 | unsafety: self.lower_unsafety(h.unsafety), |
1266 | asyncness: self.lower_asyncness(h.asyncness), | |
1267 | constness: self.lower_constness(h.constness), | |
94222f64 | 1268 | abi: self.lower_extern(h.ext), |
416331ca XL |
1269 | } |
1270 | } | |
1271 | ||
60c5eb7d | 1272 | pub(super) fn lower_abi(&mut self, abi: StrLit) -> abi::Abi { |
add651ee FG |
1273 | abi::lookup(abi.symbol_unescaped.as_str()).unwrap_or_else(|err| { |
1274 | self.error_on_invalid_abi(abi, err); | |
60c5eb7d XL |
1275 | abi::Abi::Rust |
1276 | }) | |
416331ca XL |
1277 | } |
1278 | ||
94222f64 | 1279 | pub(super) fn lower_extern(&mut self, ext: Extern) -> abi::Abi { |
60c5eb7d XL |
1280 | match ext { |
1281 | Extern::None => abi::Abi::Rust, | |
064997fb FG |
1282 | Extern::Implicit(_) => abi::Abi::FALLBACK, |
1283 | Extern::Explicit(abi, _) => self.lower_abi(abi), | |
416331ca XL |
1284 | } |
1285 | } | |
1286 | ||
add651ee | 1287 | fn error_on_invalid_abi(&self, abi: StrLit, err: abi::AbiUnsupported) { |
2b03887a FG |
1288 | let abi_names = abi::enabled_names(self.tcx.features(), abi.span) |
1289 | .iter() | |
1290 | .map(|s| Symbol::intern(s)) | |
1291 | .collect::<Vec<_>>(); | |
1292 | let suggested_name = find_best_match_for_name(&abi_names, abi.symbol_unescaped, None); | |
f2b60f7d | 1293 | self.tcx.sess.emit_err(InvalidAbi { |
2b03887a | 1294 | abi: abi.symbol_unescaped, |
f2b60f7d | 1295 | span: abi.span, |
add651ee FG |
1296 | explain: match err { |
1297 | abi::AbiUnsupported::Reason { explain } => Some(InvalidAbiReason(explain)), | |
1298 | _ => None, | |
1299 | }, | |
2b03887a FG |
1300 | suggestion: suggested_name.map(|suggested_name| InvalidAbiSuggestion { |
1301 | span: abi.span, | |
1302 | suggestion: format!("\"{suggested_name}\""), | |
1303 | }), | |
1304 | command: "rustc --print=calling-conventions".to_string(), | |
f2b60f7d | 1305 | }); |
60c5eb7d XL |
1306 | } |
1307 | ||
74b04a01 | 1308 | fn lower_asyncness(&mut self, a: Async) -> hir::IsAsync { |
416331ca | 1309 | match a { |
781aab86 | 1310 | Async::Yes { span, .. } => hir::IsAsync::Async(span), |
74b04a01 XL |
1311 | Async::No => hir::IsAsync::NotAsync, |
1312 | } | |
1313 | } | |
1314 | ||
9c376795 | 1315 | pub(super) fn lower_constness(&mut self, c: Const) -> hir::Constness { |
74b04a01 XL |
1316 | match c { |
1317 | Const::Yes(_) => hir::Constness::Const, | |
1318 | Const::No => hir::Constness::NotConst, | |
1319 | } | |
1320 | } | |
1321 | ||
1322 | pub(super) fn lower_unsafety(&mut self, u: Unsafe) -> hir::Unsafety { | |
1323 | match u { | |
1324 | Unsafe::Yes(_) => hir::Unsafety::Unsafe, | |
1325 | Unsafe::No => hir::Unsafety::Normal, | |
416331ca XL |
1326 | } |
1327 | } | |
1328 | ||
923072b8 FG |
1329 | /// Return the pair of the lowered `generics` as `hir::Generics` and the evaluation of `f` with |
1330 | /// the carried impl trait definitions and bounds. | |
1331 | #[instrument(level = "debug", skip(self, f))] | |
1332 | fn lower_generics<T>( | |
416331ca XL |
1333 | &mut self, |
1334 | generics: &Generics, | |
fe692bf9 | 1335 | constness: Const, |
923072b8 | 1336 | parent_node_id: NodeId, |
f2b60f7d | 1337 | itctx: &ImplTraitContext, |
923072b8 FG |
1338 | f: impl FnOnce(&mut Self) -> T, |
1339 | ) -> (&'hir hir::Generics<'hir>, T) { | |
1340 | debug_assert!(self.impl_trait_defs.is_empty()); | |
1341 | debug_assert!(self.impl_trait_bounds.is_empty()); | |
1342 | ||
5e7ed085 | 1343 | // Error if `?Trait` bounds in where clauses don't refer directly to type parameters. |
c295e0f8 XL |
1344 | // Note: we used to clone these bounds directly onto the type parameter (and avoid lowering |
1345 | // these into hir when we lower thee where clauses), but this makes it quite difficult to | |
1346 | // keep track of the Span info. Now, `add_implicitly_sized` in `AstConv` checks both param bounds and | |
1347 | // where clauses for `?Sized`. | |
416331ca | 1348 | for pred in &generics.where_clause.predicates { |
487cf647 | 1349 | let WherePredicate::BoundPredicate(bound_pred) = pred else { |
5e7ed085 | 1350 | continue; |
c295e0f8 XL |
1351 | }; |
1352 | let compute_is_param = || { | |
1353 | // Check if the where clause type is a plain type parameter. | |
1354 | match self | |
1355 | .resolver | |
1356 | .get_partial_res(bound_pred.bounded_ty.id) | |
2b03887a | 1357 | .and_then(|r| r.full_res()) |
c295e0f8 | 1358 | { |
2b03887a | 1359 | Some(Res::Def(DefKind::TyParam, def_id)) |
c295e0f8 XL |
1360 | if bound_pred.bound_generic_params.is_empty() => |
1361 | { | |
1362 | generics | |
1363 | .params | |
1364 | .iter() | |
923072b8 | 1365 | .any(|p| def_id == self.local_def_id(p.id).to_def_id()) |
416331ca | 1366 | } |
c295e0f8 XL |
1367 | // Either the `bounded_ty` is not a plain type parameter, or |
1368 | // it's not found in the generic type parameters list. | |
1369 | _ => false, | |
1370 | } | |
1371 | }; | |
1372 | // We only need to compute this once per `WherePredicate`, but don't | |
1373 | // need to compute this at all unless there is a Maybe bound. | |
1374 | let mut is_param: Option<bool> = None; | |
1375 | for bound in &bound_pred.bounds { | |
1376 | if !matches!(*bound, GenericBound::Trait(_, TraitBoundModifier::Maybe)) { | |
1377 | continue; | |
1378 | } | |
1379 | let is_param = *is_param.get_or_insert_with(compute_is_param); | |
1380 | if !is_param { | |
f2b60f7d | 1381 | self.tcx.sess.emit_err(MisplacedRelaxTraitBound { span: bound.span() }); |
416331ca XL |
1382 | } |
1383 | } | |
1384 | } | |
1385 | ||
add651ee FG |
1386 | // Desugar `~const` bound in generics into an additional `const host: bool` param |
1387 | // if the effects feature is enabled. This needs to be done before we lower where | |
1388 | // clauses since where clauses need to bind to the DefId of the host param | |
ed00b5ec FG |
1389 | let host_param_parts = if let Const::Yes(span) = constness |
1390 | && self.tcx.features().effects | |
1391 | { | |
1392 | if let Some(param) = | |
1393 | generics.params.iter().find(|x| x.attrs.iter().any(|x| x.has_name(sym::rustc_host))) | |
1394 | { | |
add651ee FG |
1395 | // user has manually specified a `rustc_host` param, in this case, we set |
1396 | // the param id so that lowering logic can use that. But we don't create | |
1397 | // another host param, so this gives `None`. | |
1398 | self.host_param_id = Some(self.local_def_id(param.id)); | |
1399 | None | |
1400 | } else { | |
1401 | let param_node_id = self.next_node_id(); | |
1402 | let hir_id = self.next_id(); | |
ed00b5ec FG |
1403 | let def_id = self.create_def( |
1404 | self.local_def_id(parent_node_id), | |
1405 | param_node_id, | |
1406 | DefPathData::TypeNs(sym::host), | |
1407 | span, | |
1408 | ); | |
add651ee FG |
1409 | self.host_param_id = Some(def_id); |
1410 | Some((span, hir_id, def_id)) | |
1411 | } | |
1412 | } else { | |
1413 | None | |
1414 | }; | |
1415 | ||
923072b8 | 1416 | let mut predicates: SmallVec<[hir::WherePredicate<'hir>; 4]> = SmallVec::new(); |
04454e1e | 1417 | predicates.extend(generics.params.iter().filter_map(|param| { |
04454e1e FG |
1418 | self.lower_generic_bound_predicate( |
1419 | param.ident, | |
1420 | param.id, | |
1421 | ¶m.kind, | |
064997fb | 1422 | ¶m.bounds, |
9c376795 FG |
1423 | param.colon_span, |
1424 | generics.span, | |
064997fb | 1425 | itctx, |
04454e1e FG |
1426 | PredicateOrigin::GenericParam, |
1427 | ) | |
1428 | })); | |
1429 | predicates.extend( | |
1430 | generics | |
1431 | .where_clause | |
1432 | .predicates | |
1433 | .iter() | |
1434 | .map(|predicate| self.lower_where_predicate(predicate)), | |
1435 | ); | |
1436 | ||
9ffffee4 FG |
1437 | let mut params: SmallVec<[hir::GenericParam<'hir>; 4]> = self |
1438 | .lower_generic_params_mut(&generics.params, hir::GenericParamSource::Generics) | |
1439 | .collect(); | |
416331ca | 1440 | |
923072b8 FG |
1441 | // Introduce extra lifetimes if late resolution tells us to. |
1442 | let extra_lifetimes = self.resolver.take_extra_lifetime_params(parent_node_id); | |
1443 | params.extend(extra_lifetimes.into_iter().filter_map(|(ident, node_id, res)| { | |
9ffffee4 FG |
1444 | self.lifetime_res_to_generic_param( |
1445 | ident, | |
1446 | node_id, | |
1447 | res, | |
1448 | hir::GenericParamSource::Generics, | |
1449 | ) | |
923072b8 FG |
1450 | })); |
1451 | ||
1452 | let has_where_clause_predicates = !generics.where_clause.predicates.is_empty(); | |
1453 | let where_clause_span = self.lower_span(generics.where_clause.span); | |
1454 | let span = self.lower_span(generics.span); | |
1455 | let res = f(self); | |
1456 | ||
1457 | let impl_trait_defs = std::mem::take(&mut self.impl_trait_defs); | |
1458 | params.extend(impl_trait_defs.into_iter()); | |
1459 | ||
1460 | let impl_trait_bounds = std::mem::take(&mut self.impl_trait_bounds); | |
1461 | predicates.extend(impl_trait_bounds.into_iter()); | |
1462 | ||
add651ee | 1463 | if let Some((span, hir_id, def_id)) = host_param_parts { |
fe692bf9 | 1464 | let const_node_id = self.next_node_id(); |
add651ee FG |
1465 | let anon_const: LocalDefId = |
1466 | self.create_def(def_id, const_node_id, DefPathData::AnonConst, span); | |
fe692bf9 | 1467 | |
fe692bf9 FG |
1468 | let const_id = self.next_id(); |
1469 | let const_expr_id = self.next_id(); | |
1470 | let bool_id = self.next_id(); | |
1471 | ||
1472 | self.children.push((def_id, hir::MaybeOwner::NonOwner(hir_id))); | |
1473 | self.children.push((anon_const, hir::MaybeOwner::NonOwner(const_id))); | |
1474 | ||
1475 | let attr_id = self.tcx.sess.parse_sess.attr_id_generator.mk_attr_id(); | |
1476 | ||
add651ee FG |
1477 | let attrs = self.arena.alloc_from_iter([Attribute { |
1478 | kind: AttrKind::Normal(P(NormalAttr::from_ident(Ident::new( | |
1479 | sym::rustc_host, | |
fe692bf9 | 1480 | span, |
add651ee FG |
1481 | )))), |
1482 | span, | |
1483 | id: attr_id, | |
1484 | style: AttrStyle::Outer, | |
1485 | }]); | |
fe692bf9 FG |
1486 | self.attrs.insert(hir_id.local_id, attrs); |
1487 | ||
1488 | let const_body = self.lower_body(|this| { | |
1489 | ( | |
1490 | &[], | |
1491 | hir::Expr { | |
1492 | hir_id: const_expr_id, | |
1493 | kind: hir::ExprKind::Lit( | |
1494 | this.arena.alloc(hir::Lit { node: LitKind::Bool(true), span }), | |
1495 | ), | |
1496 | span, | |
1497 | }, | |
1498 | ) | |
1499 | }); | |
1500 | ||
1501 | let param = hir::GenericParam { | |
1502 | def_id, | |
1503 | hir_id, | |
1504 | name: hir::ParamName::Plain(Ident { name: sym::host, span }), | |
1505 | span, | |
1506 | kind: hir::GenericParamKind::Const { | |
1507 | ty: self.arena.alloc(self.ty( | |
1508 | span, | |
1509 | hir::TyKind::Path(hir::QPath::Resolved( | |
1510 | None, | |
1511 | self.arena.alloc(hir::Path { | |
1512 | res: Res::PrimTy(hir::PrimTy::Bool), | |
1513 | span, | |
1514 | segments: self.arena.alloc_from_iter([hir::PathSegment { | |
1515 | ident: Ident { name: sym::bool, span }, | |
1516 | hir_id: bool_id, | |
1517 | res: Res::PrimTy(hir::PrimTy::Bool), | |
1518 | args: None, | |
1519 | infer_args: false, | |
1520 | }]), | |
1521 | }), | |
1522 | )), | |
1523 | )), | |
add651ee FG |
1524 | default: Some(hir::AnonConst { |
1525 | def_id: anon_const, | |
1526 | hir_id: const_id, | |
1527 | body: const_body, | |
1528 | }), | |
fe692bf9 FG |
1529 | }, |
1530 | colon_span: None, | |
1531 | pure_wrt_drop: false, | |
1532 | source: hir::GenericParamSource::Generics, | |
1533 | }; | |
1534 | ||
1535 | params.push(param); | |
1536 | } | |
1537 | ||
923072b8 FG |
1538 | let lowered_generics = self.arena.alloc(hir::Generics { |
1539 | params: self.arena.alloc_from_iter(params), | |
1540 | predicates: self.arena.alloc_from_iter(predicates), | |
1541 | has_where_clause_predicates, | |
1542 | where_clause_span, | |
1543 | span, | |
1544 | }); | |
1545 | ||
1546 | (lowered_generics, res) | |
dfeec247 XL |
1547 | } |
1548 | ||
04454e1e FG |
1549 | pub(super) fn lower_generic_bound_predicate( |
1550 | &mut self, | |
1551 | ident: Ident, | |
1552 | id: NodeId, | |
1553 | kind: &GenericParamKind, | |
064997fb | 1554 | bounds: &[GenericBound], |
9c376795 FG |
1555 | colon_span: Option<Span>, |
1556 | parent_span: Span, | |
f2b60f7d | 1557 | itctx: &ImplTraitContext, |
04454e1e FG |
1558 | origin: PredicateOrigin, |
1559 | ) -> Option<hir::WherePredicate<'hir>> { | |
1560 | // Do not create a clause if we do not have anything inside it. | |
1561 | if bounds.is_empty() { | |
1562 | return None; | |
1563 | } | |
064997fb FG |
1564 | |
1565 | let bounds = self.lower_param_bounds(bounds, itctx); | |
1566 | ||
04454e1e FG |
1567 | let ident = self.lower_ident(ident); |
1568 | let param_span = ident.span; | |
9c376795 FG |
1569 | |
1570 | // Reconstruct the span of the entire predicate from the individual generic bounds. | |
1571 | let span_start = colon_span.unwrap_or_else(|| param_span.shrink_to_hi()); | |
1572 | let span = bounds.iter().fold(span_start, |span_accum, bound| { | |
1573 | match bound.span().find_ancestor_inside(parent_span) { | |
1574 | Some(bound_span) => span_accum.to(bound_span), | |
1575 | None => span_accum, | |
1576 | } | |
1577 | }); | |
1578 | let span = self.lower_span(span); | |
1579 | ||
04454e1e FG |
1580 | match kind { |
1581 | GenericParamKind::Const { .. } => None, | |
1582 | GenericParamKind::Type { .. } => { | |
923072b8 | 1583 | let def_id = self.local_def_id(id).to_def_id(); |
f2b60f7d FG |
1584 | let hir_id = self.next_id(); |
1585 | let res = Res::Def(DefKind::TyParam, def_id); | |
04454e1e FG |
1586 | let ty_path = self.arena.alloc(hir::Path { |
1587 | span: param_span, | |
f2b60f7d FG |
1588 | res, |
1589 | segments: self | |
1590 | .arena | |
1591 | .alloc_from_iter([hir::PathSegment::new(ident, hir_id, res)]), | |
04454e1e FG |
1592 | }); |
1593 | let ty_id = self.next_id(); | |
1594 | let bounded_ty = | |
1595 | self.ty_path(ty_id, param_span, hir::QPath::Resolved(None, ty_path)); | |
1596 | Some(hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate { | |
2b03887a | 1597 | hir_id: self.next_id(), |
04454e1e FG |
1598 | bounded_ty: self.arena.alloc(bounded_ty), |
1599 | bounds, | |
1600 | span, | |
1601 | bound_generic_params: &[], | |
1602 | origin, | |
1603 | })) | |
dfeec247 | 1604 | } |
04454e1e | 1605 | GenericParamKind::Lifetime => { |
04454e1e | 1606 | let ident = self.lower_ident(ident); |
923072b8 | 1607 | let lt_id = self.next_node_id(); |
487cf647 | 1608 | let lifetime = self.new_named_lifetime(id, lt_id, ident); |
04454e1e FG |
1609 | Some(hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate { |
1610 | lifetime, | |
1611 | span, | |
1612 | bounds, | |
1613 | in_where_clause: false, | |
1614 | })) | |
1615 | } | |
1616 | } | |
416331ca XL |
1617 | } |
1618 | ||
dfeec247 | 1619 | fn lower_where_predicate(&mut self, pred: &WherePredicate) -> hir::WherePredicate<'hir> { |
487cf647 | 1620 | match pred { |
416331ca | 1621 | WherePredicate::BoundPredicate(WhereBoundPredicate { |
487cf647 FG |
1622 | bound_generic_params, |
1623 | bounded_ty, | |
1624 | bounds, | |
416331ca | 1625 | span, |
04454e1e | 1626 | }) => hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate { |
2b03887a | 1627 | hir_id: self.next_id(), |
9ffffee4 FG |
1628 | bound_generic_params: self |
1629 | .lower_generic_params(bound_generic_params, hir::GenericParamSource::Binder), | |
04454e1e | 1630 | bounded_ty: self |
9ffffee4 | 1631 | .lower_ty(bounded_ty, &ImplTraitContext::Disallowed(ImplTraitPosition::Bound)), |
ed00b5ec FG |
1632 | bounds: self.lower_param_bounds( |
1633 | bounds, | |
1634 | &ImplTraitContext::Disallowed(ImplTraitPosition::Bound), | |
1635 | ), | |
487cf647 | 1636 | span: self.lower_span(*span), |
04454e1e | 1637 | origin: PredicateOrigin::WhereClause, |
c295e0f8 | 1638 | }), |
487cf647 FG |
1639 | WherePredicate::RegionPredicate(WhereRegionPredicate { lifetime, bounds, span }) => { |
1640 | hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate { | |
1641 | span: self.lower_span(*span), | |
1642 | lifetime: self.lower_lifetime(lifetime), | |
1643 | bounds: self.lower_param_bounds( | |
1644 | bounds, | |
1645 | &ImplTraitContext::Disallowed(ImplTraitPosition::Bound), | |
1646 | ), | |
1647 | in_where_clause: true, | |
1648 | }) | |
1649 | } | |
1650 | WherePredicate::EqPredicate(WhereEqPredicate { lhs_ty, rhs_ty, span }) => { | |
416331ca | 1651 | hir::WherePredicate::EqPredicate(hir::WhereEqPredicate { |
5099ac24 | 1652 | lhs_ty: self |
9ffffee4 | 1653 | .lower_ty(lhs_ty, &ImplTraitContext::Disallowed(ImplTraitPosition::Bound)), |
5099ac24 | 1654 | rhs_ty: self |
9ffffee4 | 1655 | .lower_ty(rhs_ty, &ImplTraitContext::Disallowed(ImplTraitPosition::Bound)), |
487cf647 | 1656 | span: self.lower_span(*span), |
416331ca | 1657 | }) |
dfeec247 XL |
1658 | } |
1659 | } | |
1660 | } | |
1661 | } |