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Commit | Line | Data |
---|---|---|
dfeec247 | 1 | use super::{AnonymousLifetimeMode, LoweringContext, ParamMode}; |
f035d41b | 2 | use super::{ImplTraitContext, ImplTraitPosition}; |
ba9703b0 | 3 | use crate::Arena; |
dfeec247 | 4 | |
74b04a01 | 5 | use rustc_ast::node_id::NodeMap; |
ba9703b0 | 6 | use rustc_ast::ptr::P; |
3dfed10e XL |
7 | use rustc_ast::visit::{self, AssocCtxt, FnCtxt, FnKind, Visitor}; |
8 | use rustc_ast::*; | |
f035d41b | 9 | use rustc_data_structures::fx::FxHashSet; |
dfeec247 XL |
10 | use rustc_errors::struct_span_err; |
11 | use rustc_hir as hir; | |
12 | use rustc_hir::def::{DefKind, Res}; | |
ba9703b0 | 13 | use rustc_hir::def_id::LocalDefId; |
dfeec247 | 14 | use rustc_span::source_map::{respan, DesugaringKind}; |
f9f354fc | 15 | use rustc_span::symbol::{kw, sym, Ident}; |
dfeec247 | 16 | use rustc_span::Span; |
60c5eb7d | 17 | use rustc_target::spec::abi; |
dfeec247 | 18 | use smallvec::{smallvec, SmallVec}; |
3dfed10e | 19 | use tracing::debug; |
60c5eb7d | 20 | |
cdc7bbd5 | 21 | use std::iter; |
6a06907d XL |
22 | use std::mem; |
23 | ||
dfeec247 XL |
24 | pub(super) struct ItemLowerer<'a, 'lowering, 'hir> { |
25 | pub(super) lctx: &'a mut LoweringContext<'lowering, 'hir>, | |
416331ca XL |
26 | } |
27 | ||
dfeec247 XL |
28 | impl ItemLowerer<'_, '_, '_> { |
29 | fn with_trait_impl_ref(&mut self, impl_ref: &Option<TraitRef>, f: impl FnOnce(&mut Self)) { | |
416331ca | 30 | let old = self.lctx.is_in_trait_impl; |
1b1a35ee | 31 | self.lctx.is_in_trait_impl = impl_ref.is_some(); |
416331ca XL |
32 | f(self); |
33 | self.lctx.is_in_trait_impl = old; | |
34 | } | |
35 | } | |
36 | ||
dfeec247 | 37 | impl<'a> Visitor<'a> for ItemLowerer<'a, '_, '_> { |
dfeec247 | 38 | fn visit_item(&mut self, item: &'a Item) { |
416331ca XL |
39 | let mut item_hir_id = None; |
40 | self.lctx.with_hir_id_owner(item.id, |lctx| { | |
e1599b0c XL |
41 | lctx.without_in_scope_lifetime_defs(|lctx| { |
42 | if let Some(hir_item) = lctx.lower_item(item) { | |
6a06907d XL |
43 | let id = lctx.insert_item(hir_item); |
44 | item_hir_id = Some(id); | |
e1599b0c XL |
45 | } |
46 | }) | |
416331ca XL |
47 | }); |
48 | ||
49 | if let Some(hir_id) = item_hir_id { | |
50 | self.lctx.with_parent_item_lifetime_defs(hir_id, |this| { | |
51 | let this = &mut ItemLowerer { lctx: this }; | |
6a06907d XL |
52 | match item.kind { |
53 | ItemKind::Mod(..) => { | |
54 | let def_id = this.lctx.lower_node_id(item.id).expect_owner(); | |
55 | let old_current_module = | |
56 | mem::replace(&mut this.lctx.current_module, def_id); | |
57 | visit::walk_item(this, item); | |
58 | this.lctx.current_module = old_current_module; | |
59 | } | |
60 | ItemKind::Impl(box ImplKind { ref of_trait, .. }) => { | |
61 | this.with_trait_impl_ref(of_trait, |this| visit::walk_item(this, item)); | |
62 | } | |
63 | _ => visit::walk_item(this, item), | |
416331ca XL |
64 | } |
65 | }); | |
66 | } | |
67 | } | |
68 | ||
3dfed10e XL |
69 | fn visit_fn(&mut self, fk: FnKind<'a>, sp: Span, _: NodeId) { |
70 | match fk { | |
71 | FnKind::Fn(FnCtxt::Foreign, _, sig, _, _) => { | |
72 | self.visit_fn_header(&sig.header); | |
73 | visit::walk_fn_decl(self, &sig.decl); | |
74 | // Don't visit the foreign function body even if it has one, since lowering the | |
75 | // body would have no meaning and will have already been caught as a parse error. | |
76 | } | |
77 | _ => visit::walk_fn(self, fk, sp), | |
78 | } | |
79 | } | |
80 | ||
74b04a01 XL |
81 | fn visit_assoc_item(&mut self, item: &'a AssocItem, ctxt: AssocCtxt) { |
82 | self.lctx.with_hir_id_owner(item.id, |lctx| match ctxt { | |
83 | AssocCtxt::Trait => { | |
84 | let hir_item = lctx.lower_trait_item(item); | |
6a06907d | 85 | let id = hir_item.trait_item_id(); |
74b04a01 | 86 | lctx.trait_items.insert(id, hir_item); |
6a06907d | 87 | lctx.modules.entry(lctx.current_module).or_default().trait_items.insert(id); |
74b04a01 XL |
88 | } |
89 | AssocCtxt::Impl => { | |
90 | let hir_item = lctx.lower_impl_item(item); | |
6a06907d | 91 | let id = hir_item.impl_item_id(); |
74b04a01 | 92 | lctx.impl_items.insert(id, hir_item); |
6a06907d | 93 | lctx.modules.entry(lctx.current_module).or_default().impl_items.insert(id); |
74b04a01 | 94 | } |
416331ca XL |
95 | }); |
96 | ||
74b04a01 | 97 | visit::walk_assoc_item(self, item, ctxt); |
416331ca | 98 | } |
fc512014 XL |
99 | |
100 | fn visit_foreign_item(&mut self, item: &'a ForeignItem) { | |
101 | self.lctx.allocate_hir_id_counter(item.id); | |
102 | self.lctx.with_hir_id_owner(item.id, |lctx| { | |
103 | let hir_item = lctx.lower_foreign_item(item); | |
6a06907d | 104 | let id = hir_item.foreign_item_id(); |
fc512014 | 105 | lctx.foreign_items.insert(id, hir_item); |
6a06907d | 106 | lctx.modules.entry(lctx.current_module).or_default().foreign_items.insert(id); |
fc512014 XL |
107 | }); |
108 | ||
109 | visit::walk_foreign_item(self, item); | |
110 | } | |
416331ca XL |
111 | } |
112 | ||
dfeec247 | 113 | impl<'hir> LoweringContext<'_, 'hir> { |
416331ca XL |
114 | // Same as the method above, but accepts `hir::GenericParam`s |
115 | // instead of `ast::GenericParam`s. | |
116 | // This should only be used with generics that have already had their | |
117 | // in-band lifetimes added. In practice, this means that this function is | |
118 | // only used when lowering a child item of a trait or impl. | |
119 | fn with_parent_item_lifetime_defs<T>( | |
120 | &mut self, | |
6a06907d | 121 | parent_hir_id: hir::ItemId, |
dfeec247 | 122 | f: impl FnOnce(&mut LoweringContext<'_, '_>) -> T, |
416331ca XL |
123 | ) -> T { |
124 | let old_len = self.in_scope_lifetimes.len(); | |
125 | ||
e74abb32 | 126 | let parent_generics = match self.items.get(&parent_hir_id).unwrap().kind { |
5869c6ff | 127 | hir::ItemKind::Impl(hir::Impl { ref generics, .. }) |
6a06907d | 128 | | hir::ItemKind::Trait(_, _, ref generics, ..) => generics.params, |
416331ca XL |
129 | _ => &[], |
130 | }; | |
131 | let lt_def_names = parent_generics.iter().filter_map(|param| match param.kind { | |
ba9703b0 | 132 | hir::GenericParamKind::Lifetime { .. } => Some(param.name.normalize_to_macros_2_0()), |
416331ca XL |
133 | _ => None, |
134 | }); | |
135 | self.in_scope_lifetimes.extend(lt_def_names); | |
136 | ||
137 | let res = f(self); | |
138 | ||
139 | self.in_scope_lifetimes.truncate(old_len); | |
140 | res | |
141 | } | |
142 | ||
e1599b0c XL |
143 | // Clears (and restores) the `in_scope_lifetimes` field. Used when |
144 | // visiting nested items, which never inherit in-scope lifetimes | |
145 | // from their surrounding environment. | |
146 | fn without_in_scope_lifetime_defs<T>( | |
147 | &mut self, | |
dfeec247 | 148 | f: impl FnOnce(&mut LoweringContext<'_, '_>) -> T, |
e1599b0c | 149 | ) -> T { |
6a06907d | 150 | let old_in_scope_lifetimes = mem::replace(&mut self.in_scope_lifetimes, vec![]); |
e1599b0c XL |
151 | |
152 | // this vector is only used when walking over impl headers, | |
153 | // input types, and the like, and should not be non-empty in | |
154 | // between items | |
155 | assert!(self.lifetimes_to_define.is_empty()); | |
156 | ||
157 | let res = f(self); | |
158 | ||
159 | assert!(self.in_scope_lifetimes.is_empty()); | |
160 | self.in_scope_lifetimes = old_in_scope_lifetimes; | |
161 | ||
162 | res | |
163 | } | |
164 | ||
6a06907d | 165 | pub(super) fn lower_mod(&mut self, items: &[P<Item>], inner: Span) -> hir::Mod<'hir> { |
416331ca | 166 | hir::Mod { |
6a06907d XL |
167 | inner, |
168 | item_ids: self.arena.alloc_from_iter(items.iter().flat_map(|x| self.lower_item_id(x))), | |
416331ca XL |
169 | } |
170 | } | |
171 | ||
172 | pub(super) fn lower_item_id(&mut self, i: &Item) -> SmallVec<[hir::ItemId; 1]> { | |
e74abb32 | 173 | let node_ids = match i.kind { |
416331ca XL |
174 | ItemKind::Use(ref use_tree) => { |
175 | let mut vec = smallvec![i.id]; | |
176 | self.lower_item_id_use_tree(use_tree, i.id, &mut vec); | |
177 | vec | |
178 | } | |
179 | ItemKind::MacroDef(..) => SmallVec::new(), | |
5869c6ff XL |
180 | ItemKind::Fn(..) | ItemKind::Impl(box ImplKind { of_trait: None, .. }) => { |
181 | smallvec![i.id] | |
182 | } | |
416331ca XL |
183 | _ => smallvec![i.id], |
184 | }; | |
185 | ||
dfeec247 XL |
186 | node_ids |
187 | .into_iter() | |
6a06907d XL |
188 | .map(|node_id| hir::ItemId { |
189 | def_id: self.allocate_hir_id_counter(node_id).expect_owner(), | |
190 | }) | |
dfeec247 | 191 | .collect() |
416331ca XL |
192 | } |
193 | ||
194 | fn lower_item_id_use_tree( | |
195 | &mut self, | |
196 | tree: &UseTree, | |
197 | base_id: NodeId, | |
dfeec247 | 198 | vec: &mut SmallVec<[NodeId; 1]>, |
416331ca XL |
199 | ) { |
200 | match tree.kind { | |
dfeec247 XL |
201 | UseTreeKind::Nested(ref nested_vec) => { |
202 | for &(ref nested, id) in nested_vec { | |
203 | vec.push(id); | |
204 | self.lower_item_id_use_tree(nested, id, vec); | |
205 | } | |
206 | } | |
416331ca XL |
207 | UseTreeKind::Glob => {} |
208 | UseTreeKind::Simple(_, id1, id2) => { | |
dfeec247 | 209 | for (_, &id) in |
cdc7bbd5 | 210 | iter::zip(self.expect_full_res_from_use(base_id).skip(1), &[id1, id2]) |
416331ca XL |
211 | { |
212 | vec.push(id); | |
213 | } | |
dfeec247 | 214 | } |
416331ca XL |
215 | } |
216 | } | |
217 | ||
dfeec247 | 218 | pub fn lower_item(&mut self, i: &Item) -> Option<hir::Item<'hir>> { |
416331ca XL |
219 | let mut ident = i.ident; |
220 | let mut vis = self.lower_visibility(&i.vis, None); | |
416331ca | 221 | |
ba9703b0 | 222 | if let ItemKind::MacroDef(MacroDef { ref body, macro_rules }) = i.kind { |
3dfed10e | 223 | if !macro_rules || self.sess.contains_name(&i.attrs, sym::macro_export) { |
416331ca | 224 | let hir_id = self.lower_node_id(i.id); |
6a06907d | 225 | self.lower_attrs(hir_id, &i.attrs); |
ba9703b0 | 226 | let body = P(self.lower_mac_args(body)); |
416331ca | 227 | self.exported_macros.push(hir::MacroDef { |
ba9703b0 | 228 | ident, |
416331ca | 229 | vis, |
6a06907d | 230 | def_id: hir_id.expect_owner(), |
416331ca | 231 | span: i.span, |
ba9703b0 | 232 | ast: MacroDef { body, macro_rules }, |
416331ca XL |
233 | }); |
234 | } else { | |
6a06907d XL |
235 | for a in i.attrs.iter() { |
236 | let a = self.lower_attr(a); | |
237 | self.non_exported_macro_attrs.push(a); | |
238 | } | |
416331ca XL |
239 | } |
240 | return None; | |
241 | } | |
242 | ||
6a06907d XL |
243 | let hir_id = self.lower_node_id(i.id); |
244 | let attrs = self.lower_attrs(hir_id, &i.attrs); | |
245 | let kind = self.lower_item_kind(i.span, i.id, hir_id, &mut ident, attrs, &mut vis, &i.kind); | |
246 | Some(hir::Item { def_id: hir_id.expect_owner(), ident, kind, vis, span: i.span }) | |
416331ca XL |
247 | } |
248 | ||
249 | fn lower_item_kind( | |
250 | &mut self, | |
dfeec247 | 251 | span: Span, |
416331ca | 252 | id: NodeId, |
6a06907d | 253 | hir_id: hir::HirId, |
416331ca | 254 | ident: &mut Ident, |
6a06907d | 255 | attrs: Option<&'hir [Attribute]>, |
dfeec247 | 256 | vis: &mut hir::Visibility<'hir>, |
416331ca | 257 | i: &ItemKind, |
dfeec247 | 258 | ) -> hir::ItemKind<'hir> { |
416331ca XL |
259 | match *i { |
260 | ItemKind::ExternCrate(orig_name) => hir::ItemKind::ExternCrate(orig_name), | |
261 | ItemKind::Use(ref use_tree) => { | |
262 | // Start with an empty prefix. | |
1b1a35ee | 263 | let prefix = Path { segments: vec![], span: use_tree.span, tokens: None }; |
416331ca XL |
264 | |
265 | self.lower_use_tree(use_tree, &prefix, id, vis, ident, attrs) | |
266 | } | |
267 | ItemKind::Static(ref t, m, ref e) => { | |
74b04a01 XL |
268 | let (ty, body_id) = self.lower_const_item(t, span, e.as_deref()); |
269 | hir::ItemKind::Static(ty, m, body_id) | |
416331ca | 270 | } |
74b04a01 XL |
271 | ItemKind::Const(_, ref t, ref e) => { |
272 | let (ty, body_id) = self.lower_const_item(t, span, e.as_deref()); | |
273 | hir::ItemKind::Const(ty, body_id) | |
416331ca | 274 | } |
5869c6ff | 275 | ItemKind::Fn(box FnKind( |
3dfed10e XL |
276 | _, |
277 | FnSig { ref decl, header, span: fn_sig_span }, | |
278 | ref generics, | |
279 | ref body, | |
5869c6ff | 280 | )) => { |
f035d41b | 281 | let fn_def_id = self.resolver.local_def_id(id); |
416331ca XL |
282 | self.with_new_scopes(|this| { |
283 | this.current_item = Some(ident.span); | |
284 | ||
285 | // Note: we don't need to change the return type from `T` to | |
286 | // `impl Future<Output = T>` here because lower_body | |
287 | // only cares about the input argument patterns in the function | |
288 | // declaration (decl), not the return types. | |
74b04a01 | 289 | let asyncness = header.asyncness; |
dfeec247 | 290 | let body_id = |
74b04a01 | 291 | this.lower_maybe_async_body(span, &decl, asyncness, body.as_deref()); |
416331ca | 292 | |
60c5eb7d | 293 | let (generics, decl) = this.add_in_band_defs( |
416331ca XL |
294 | generics, |
295 | fn_def_id, | |
296 | AnonymousLifetimeMode::PassThrough, | |
dfeec247 | 297 | |this, idty| { |
74b04a01 | 298 | let ret_id = asyncness.opt_return_id(); |
ba9703b0 XL |
299 | this.lower_fn_decl( |
300 | &decl, | |
301 | Some((fn_def_id.to_def_id(), idty)), | |
302 | true, | |
303 | ret_id, | |
304 | ) | |
dfeec247 | 305 | }, |
416331ca | 306 | ); |
3dfed10e XL |
307 | let sig = hir::FnSig { |
308 | decl, | |
5869c6ff | 309 | header: this.lower_fn_header(header, fn_sig_span, id), |
3dfed10e XL |
310 | span: fn_sig_span, |
311 | }; | |
60c5eb7d | 312 | hir::ItemKind::Fn(sig, generics, body_id) |
416331ca XL |
313 | }) |
314 | } | |
6a06907d XL |
315 | ItemKind::Mod(_, ref mod_kind) => match mod_kind { |
316 | ModKind::Loaded(items, _, inner_span) => { | |
317 | hir::ItemKind::Mod(self.lower_mod(items, *inner_span)) | |
318 | } | |
319 | ModKind::Unloaded => panic!("`mod` items should have been loaded by now"), | |
320 | }, | |
5869c6ff XL |
321 | ItemKind::ForeignMod(ref fm) => { |
322 | if fm.abi.is_none() { | |
6a06907d | 323 | self.maybe_lint_missing_abi(span, id, abi::Abi::C { unwind: false }); |
5869c6ff XL |
324 | } |
325 | hir::ItemKind::ForeignMod { | |
6a06907d | 326 | abi: fm.abi.map_or(abi::Abi::C { unwind: false }, |abi| self.lower_abi(abi)), |
5869c6ff XL |
327 | items: self |
328 | .arena | |
329 | .alloc_from_iter(fm.items.iter().map(|x| self.lower_foreign_item_ref(x))), | |
330 | } | |
331 | } | |
17df50a5 XL |
332 | ItemKind::GlobalAsm(ref asm) => { |
333 | hir::ItemKind::GlobalAsm(self.lower_inline_asm(span, asm)) | |
334 | } | |
5869c6ff | 335 | ItemKind::TyAlias(box TyAliasKind(_, ref gen, _, Some(ref ty))) => { |
f035d41b XL |
336 | // We lower |
337 | // | |
338 | // type Foo = impl Trait | |
339 | // | |
340 | // to | |
341 | // | |
342 | // type Foo = Foo1 | |
343 | // opaque type Foo1: Trait | |
344 | let ty = self.lower_ty( | |
345 | ty, | |
136023e0 | 346 | ImplTraitContext::TypeAliasesOpaqueTy { |
f035d41b | 347 | capturable_lifetimes: &mut FxHashSet::default(), |
f035d41b XL |
348 | }, |
349 | ); | |
350 | let generics = self.lower_generics(gen, ImplTraitContext::disallowed()); | |
351 | hir::ItemKind::TyAlias(ty, generics) | |
352 | } | |
5869c6ff | 353 | ItemKind::TyAlias(box TyAliasKind(_, ref generics, _, None)) => { |
74b04a01 XL |
354 | let ty = self.arena.alloc(self.ty(span, hir::TyKind::Err)); |
355 | let generics = self.lower_generics(generics, ImplTraitContext::disallowed()); | |
356 | hir::ItemKind::TyAlias(ty, generics) | |
357 | } | |
dfeec247 XL |
358 | ItemKind::Enum(ref enum_definition, ref generics) => hir::ItemKind::Enum( |
359 | hir::EnumDef { | |
360 | variants: self.arena.alloc_from_iter( | |
361 | enum_definition.variants.iter().map(|x| self.lower_variant(x)), | |
362 | ), | |
363 | }, | |
364 | self.lower_generics(generics, ImplTraitContext::disallowed()), | |
365 | ), | |
416331ca | 366 | ItemKind::Struct(ref struct_def, ref generics) => { |
6a06907d | 367 | let struct_def = self.lower_variant_data(hir_id, struct_def); |
416331ca XL |
368 | hir::ItemKind::Struct( |
369 | struct_def, | |
370 | self.lower_generics(generics, ImplTraitContext::disallowed()), | |
371 | ) | |
372 | } | |
373 | ItemKind::Union(ref vdata, ref generics) => { | |
6a06907d | 374 | let vdata = self.lower_variant_data(hir_id, vdata); |
416331ca XL |
375 | hir::ItemKind::Union( |
376 | vdata, | |
377 | self.lower_generics(generics, ImplTraitContext::disallowed()), | |
378 | ) | |
379 | } | |
5869c6ff | 380 | ItemKind::Impl(box ImplKind { |
416331ca XL |
381 | unsafety, |
382 | polarity, | |
383 | defaultness, | |
dfeec247 XL |
384 | constness, |
385 | generics: ref ast_generics, | |
386 | of_trait: ref trait_ref, | |
387 | self_ty: ref ty, | |
388 | items: ref 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. | |
6a06907d | 403 | let lowered_trait_def_id = self.lower_node_id(id).expect_owner(); |
416331ca XL |
404 | let (generics, (trait_ref, lowered_ty)) = self.add_in_band_defs( |
405 | ast_generics, | |
6a06907d | 406 | lowered_trait_def_id, |
416331ca XL |
407 | AnonymousLifetimeMode::CreateParameter, |
408 | |this, _| { | |
409 | let trait_ref = trait_ref.as_ref().map(|trait_ref| { | |
410 | this.lower_trait_ref(trait_ref, ImplTraitContext::disallowed()) | |
411 | }); | |
412 | ||
413 | if let Some(ref trait_ref) = trait_ref { | |
414 | if let Res::Def(DefKind::Trait, def_id) = trait_ref.path.res { | |
dfeec247 XL |
415 | this.trait_impls |
416 | .entry(def_id) | |
417 | .or_default() | |
6a06907d | 418 | .push(lowered_trait_def_id); |
416331ca XL |
419 | } |
420 | } | |
421 | ||
422 | let lowered_ty = this.lower_ty(ty, ImplTraitContext::disallowed()); | |
423 | ||
424 | (trait_ref, lowered_ty) | |
425 | }, | |
426 | ); | |
427 | ||
dfeec247 XL |
428 | let new_impl_items = |
429 | self.with_in_scope_lifetime_defs(&ast_generics.params, |this| { | |
430 | this.arena.alloc_from_iter( | |
431 | impl_items.iter().map(|item| this.lower_impl_item_ref(item)), | |
432 | ) | |
433 | }); | |
416331ca | 434 | |
ba9703b0 XL |
435 | // `defaultness.has_value()` is never called for an `impl`, always `true` in order |
436 | // to not cause an assertion failure inside the `lower_defaultness` function. | |
437 | let has_val = true; | |
438 | let (defaultness, defaultness_span) = self.lower_defaultness(defaultness, has_val); | |
5869c6ff | 439 | hir::ItemKind::Impl(hir::Impl { |
74b04a01 | 440 | unsafety: self.lower_unsafety(unsafety), |
60c5eb7d | 441 | polarity, |
ba9703b0 XL |
442 | defaultness, |
443 | defaultness_span, | |
74b04a01 | 444 | constness: self.lower_constness(constness), |
416331ca | 445 | generics, |
dfeec247 XL |
446 | of_trait: trait_ref, |
447 | self_ty: lowered_ty, | |
448 | items: new_impl_items, | |
5869c6ff | 449 | }) |
416331ca | 450 | } |
5869c6ff XL |
451 | ItemKind::Trait(box TraitKind( |
452 | is_auto, | |
453 | unsafety, | |
454 | ref generics, | |
455 | ref bounds, | |
456 | ref items, | |
457 | )) => { | |
416331ca | 458 | let bounds = self.lower_param_bounds(bounds, ImplTraitContext::disallowed()); |
dfeec247 XL |
459 | let items = self |
460 | .arena | |
461 | .alloc_from_iter(items.iter().map(|item| self.lower_trait_item_ref(item))); | |
416331ca | 462 | hir::ItemKind::Trait( |
60c5eb7d | 463 | is_auto, |
74b04a01 | 464 | self.lower_unsafety(unsafety), |
416331ca XL |
465 | self.lower_generics(generics, ImplTraitContext::disallowed()), |
466 | bounds, | |
467 | items, | |
468 | ) | |
469 | } | |
470 | ItemKind::TraitAlias(ref generics, ref bounds) => hir::ItemKind::TraitAlias( | |
471 | self.lower_generics(generics, ImplTraitContext::disallowed()), | |
472 | self.lower_param_bounds(bounds, ImplTraitContext::disallowed()), | |
473 | ), | |
ba9703b0 XL |
474 | ItemKind::MacroDef(..) | ItemKind::MacCall(..) => { |
475 | panic!("`TyMac` should have been expanded by now") | |
dfeec247 | 476 | } |
416331ca | 477 | } |
416331ca XL |
478 | } |
479 | ||
74b04a01 XL |
480 | fn lower_const_item( |
481 | &mut self, | |
482 | ty: &Ty, | |
483 | span: Span, | |
484 | body: Option<&Expr>, | |
485 | ) -> (&'hir hir::Ty<'hir>, hir::BodyId) { | |
136023e0 | 486 | let ty = self.lower_ty(ty, ImplTraitContext::Disallowed(ImplTraitPosition::Binding)); |
74b04a01 XL |
487 | (ty, self.lower_const_body(span, body)) |
488 | } | |
489 | ||
416331ca XL |
490 | fn lower_use_tree( |
491 | &mut self, | |
492 | tree: &UseTree, | |
493 | prefix: &Path, | |
494 | id: NodeId, | |
dfeec247 | 495 | vis: &mut hir::Visibility<'hir>, |
416331ca | 496 | ident: &mut Ident, |
6a06907d | 497 | attrs: Option<&'hir [Attribute]>, |
dfeec247 | 498 | ) -> hir::ItemKind<'hir> { |
416331ca XL |
499 | debug!("lower_use_tree(tree={:?})", tree); |
500 | debug!("lower_use_tree: vis = {:?}", vis); | |
501 | ||
502 | let path = &tree.prefix; | |
dfeec247 | 503 | let segments = prefix.segments.iter().chain(path.segments.iter()).cloned().collect(); |
416331ca XL |
504 | |
505 | match tree.kind { | |
506 | UseTreeKind::Simple(rename, id1, id2) => { | |
507 | *ident = tree.ident(); | |
508 | ||
509 | // First, apply the prefix to the path. | |
1b1a35ee | 510 | let mut path = Path { segments, span: path.span, tokens: None }; |
416331ca XL |
511 | |
512 | // Correctly resolve `self` imports. | |
513 | if path.segments.len() > 1 | |
514 | && path.segments.last().unwrap().ident.name == kw::SelfLower | |
515 | { | |
516 | let _ = path.segments.pop(); | |
517 | if rename.is_none() { | |
518 | *ident = path.segments.last().unwrap().ident; | |
519 | } | |
520 | } | |
521 | ||
522 | let mut resolutions = self.expect_full_res_from_use(id); | |
523 | // We want to return *something* from this function, so hold onto the first item | |
524 | // for later. | |
525 | let ret_res = self.lower_res(resolutions.next().unwrap_or(Res::Err)); | |
526 | ||
527 | // Here, we are looping over namespaces, if they exist for the definition | |
528 | // being imported. We only handle type and value namespaces because we | |
529 | // won't be dealing with macros in the rest of the compiler. | |
530 | // Essentially a single `use` which imports two names is desugared into | |
531 | // two imports. | |
cdc7bbd5 | 532 | for (res, &new_node_id) in iter::zip(resolutions, &[id1, id2]) { |
416331ca XL |
533 | let ident = *ident; |
534 | let mut path = path.clone(); | |
535 | for seg in &mut path.segments { | |
60c5eb7d | 536 | seg.id = self.resolver.next_node_id(); |
416331ca XL |
537 | } |
538 | let span = path.span; | |
539 | ||
540 | self.with_hir_id_owner(new_node_id, |this| { | |
541 | let new_id = this.lower_node_id(new_node_id); | |
542 | let res = this.lower_res(res); | |
dfeec247 XL |
543 | let path = this.lower_path_extra(res, &path, ParamMode::Explicit, None); |
544 | let kind = hir::ItemKind::Use(path, hir::UseKind::Single); | |
416331ca | 545 | let vis = this.rebuild_vis(&vis); |
6a06907d XL |
546 | if let Some(attrs) = attrs { |
547 | this.attrs.insert(new_id, attrs); | |
548 | } | |
416331ca | 549 | |
dfeec247 | 550 | this.insert_item(hir::Item { |
6a06907d | 551 | def_id: new_id.expect_owner(), |
dfeec247 | 552 | ident, |
dfeec247 XL |
553 | kind, |
554 | vis, | |
555 | span, | |
556 | }); | |
416331ca XL |
557 | }); |
558 | } | |
559 | ||
dfeec247 | 560 | let path = self.lower_path_extra(ret_res, &path, ParamMode::Explicit, None); |
416331ca XL |
561 | hir::ItemKind::Use(path, hir::UseKind::Single) |
562 | } | |
563 | UseTreeKind::Glob => { | |
1b1a35ee XL |
564 | let path = self.lower_path( |
565 | id, | |
566 | &Path { segments, span: path.span, tokens: None }, | |
567 | ParamMode::Explicit, | |
568 | ); | |
416331ca XL |
569 | hir::ItemKind::Use(path, hir::UseKind::Glob) |
570 | } | |
571 | UseTreeKind::Nested(ref trees) => { | |
572 | // Nested imports are desugared into simple imports. | |
573 | // So, if we start with | |
574 | // | |
575 | // ``` | |
576 | // pub(x) use foo::{a, b}; | |
577 | // ``` | |
578 | // | |
579 | // we will create three items: | |
580 | // | |
581 | // ``` | |
582 | // pub(x) use foo::a; | |
583 | // pub(x) use foo::b; | |
584 | // pub(x) use foo::{}; // <-- this is called the `ListStem` | |
585 | // ``` | |
586 | // | |
587 | // The first two are produced by recursively invoking | |
588 | // `lower_use_tree` (and indeed there may be things | |
589 | // like `use foo::{a::{b, c}}` and so forth). They | |
590 | // wind up being directly added to | |
591 | // `self.items`. However, the structure of this | |
592 | // function also requires us to return one item, and | |
593 | // for that we return the `{}` import (called the | |
594 | // `ListStem`). | |
595 | ||
1b1a35ee | 596 | let prefix = Path { segments, span: prefix.span.to(path.span), tokens: None }; |
416331ca XL |
597 | |
598 | // Add all the nested `PathListItem`s to the HIR. | |
599 | for &(ref use_tree, id) in trees { | |
600 | let new_hir_id = self.lower_node_id(id); | |
601 | ||
602 | let mut prefix = prefix.clone(); | |
603 | ||
604 | // Give the segments new node-ids since they are being cloned. | |
605 | for seg in &mut prefix.segments { | |
60c5eb7d | 606 | seg.id = self.resolver.next_node_id(); |
416331ca XL |
607 | } |
608 | ||
609 | // Each `use` import is an item and thus are owners of the | |
610 | // names in the path. Up to this point the nested import is | |
611 | // the current owner, since we want each desugared import to | |
612 | // own its own names, we have to adjust the owner before | |
613 | // lowering the rest of the import. | |
614 | self.with_hir_id_owner(id, |this| { | |
615 | let mut vis = this.rebuild_vis(&vis); | |
616 | let mut ident = *ident; | |
617 | ||
dfeec247 XL |
618 | let kind = |
619 | this.lower_use_tree(use_tree, &prefix, id, &mut vis, &mut ident, attrs); | |
6a06907d XL |
620 | if let Some(attrs) = attrs { |
621 | this.attrs.insert(new_hir_id, attrs); | |
622 | } | |
dfeec247 XL |
623 | |
624 | this.insert_item(hir::Item { | |
6a06907d | 625 | def_id: new_hir_id.expect_owner(), |
dfeec247 | 626 | ident, |
dfeec247 XL |
627 | kind, |
628 | vis, | |
629 | span: use_tree.span, | |
630 | }); | |
416331ca XL |
631 | }); |
632 | } | |
633 | ||
634 | // Subtle and a bit hacky: we lower the privacy level | |
635 | // of the list stem to "private" most of the time, but | |
636 | // not for "restricted" paths. The key thing is that | |
637 | // we don't want it to stay as `pub` (with no caveats) | |
638 | // because that affects rustdoc and also the lints | |
639 | // about `pub` items. But we can't *always* make it | |
640 | // private -- particularly not for restricted paths -- | |
641 | // because it contains node-ids that would then be | |
642 | // unused, failing the check that HirIds are "densely | |
643 | // assigned". | |
644 | match vis.node { | |
dfeec247 XL |
645 | hir::VisibilityKind::Public |
646 | | hir::VisibilityKind::Crate(_) | |
647 | | hir::VisibilityKind::Inherited => { | |
416331ca XL |
648 | *vis = respan(prefix.span.shrink_to_lo(), hir::VisibilityKind::Inherited); |
649 | } | |
650 | hir::VisibilityKind::Restricted { .. } => { | |
651 | // Do nothing here, as described in the comment on the match. | |
652 | } | |
653 | } | |
654 | ||
655 | let res = self.expect_full_res_from_use(id).next().unwrap_or(Res::Err); | |
656 | let res = self.lower_res(res); | |
dfeec247 | 657 | let path = self.lower_path_extra(res, &prefix, ParamMode::Explicit, None); |
416331ca XL |
658 | hir::ItemKind::Use(path, hir::UseKind::ListStem) |
659 | } | |
660 | } | |
661 | } | |
662 | ||
663 | /// Paths like the visibility path in `pub(super) use foo::{bar, baz}` are repeated | |
664 | /// many times in the HIR tree; for each occurrence, we need to assign distinct | |
665 | /// `NodeId`s. (See, e.g., #56128.) | |
dfeec247 | 666 | fn rebuild_use_path(&mut self, path: &hir::Path<'hir>) -> &'hir hir::Path<'hir> { |
416331ca | 667 | debug!("rebuild_use_path(path = {:?})", path); |
dfeec247 XL |
668 | let segments = |
669 | self.arena.alloc_from_iter(path.segments.iter().map(|seg| hir::PathSegment { | |
670 | ident: seg.ident, | |
671 | hir_id: seg.hir_id.map(|_| self.next_id()), | |
672 | res: seg.res, | |
673 | args: None, | |
674 | infer_args: seg.infer_args, | |
675 | })); | |
676 | self.arena.alloc(hir::Path { span: path.span, res: path.res, segments }) | |
416331ca XL |
677 | } |
678 | ||
dfeec247 | 679 | fn rebuild_vis(&mut self, vis: &hir::Visibility<'hir>) -> hir::Visibility<'hir> { |
416331ca XL |
680 | let vis_kind = match vis.node { |
681 | hir::VisibilityKind::Public => hir::VisibilityKind::Public, | |
682 | hir::VisibilityKind::Crate(sugar) => hir::VisibilityKind::Crate(sugar), | |
683 | hir::VisibilityKind::Inherited => hir::VisibilityKind::Inherited, | |
684 | hir::VisibilityKind::Restricted { ref path, hir_id: _ } => { | |
685 | hir::VisibilityKind::Restricted { | |
dfeec247 | 686 | path: self.rebuild_use_path(path), |
416331ca XL |
687 | hir_id: self.next_id(), |
688 | } | |
689 | } | |
690 | }; | |
691 | respan(vis.span, vis_kind) | |
692 | } | |
693 | ||
dfeec247 | 694 | fn lower_foreign_item(&mut self, i: &ForeignItem) -> hir::ForeignItem<'hir> { |
6a06907d XL |
695 | let hir_id = self.lower_node_id(i.id); |
696 | let def_id = hir_id.expect_owner(); | |
697 | self.lower_attrs(hir_id, &i.attrs); | |
416331ca | 698 | hir::ForeignItem { |
6a06907d | 699 | def_id, |
416331ca | 700 | ident: i.ident, |
e74abb32 | 701 | kind: match i.kind { |
5869c6ff | 702 | ForeignItemKind::Fn(box FnKind(_, ref sig, ref generics, _)) => { |
74b04a01 | 703 | let fdec = &sig.decl; |
416331ca XL |
704 | let (generics, (fn_dec, fn_args)) = self.add_in_band_defs( |
705 | generics, | |
706 | def_id, | |
707 | AnonymousLifetimeMode::PassThrough, | |
708 | |this, _| { | |
709 | ( | |
e1599b0c | 710 | // Disallow `impl Trait` in foreign items. |
416331ca | 711 | this.lower_fn_decl(fdec, None, false, None), |
e1599b0c | 712 | this.lower_fn_params_to_names(fdec), |
416331ca XL |
713 | ) |
714 | }, | |
715 | ); | |
716 | ||
717 | hir::ForeignItemKind::Fn(fn_dec, fn_args, generics) | |
718 | } | |
74b04a01 | 719 | ForeignItemKind::Static(ref t, m, _) => { |
dfeec247 XL |
720 | let ty = self.lower_ty(t, ImplTraitContext::disallowed()); |
721 | hir::ForeignItemKind::Static(ty, m) | |
416331ca | 722 | } |
74b04a01 | 723 | ForeignItemKind::TyAlias(..) => hir::ForeignItemKind::Type, |
ba9703b0 | 724 | ForeignItemKind::MacCall(_) => panic!("macro shouldn't exist here"), |
416331ca XL |
725 | }, |
726 | vis: self.lower_visibility(&i.vis, None), | |
727 | span: i.span, | |
728 | } | |
729 | } | |
730 | ||
fc512014 XL |
731 | fn lower_foreign_item_ref(&mut self, i: &ForeignItem) -> hir::ForeignItemRef<'hir> { |
732 | hir::ForeignItemRef { | |
6a06907d | 733 | id: hir::ForeignItemId { def_id: self.lower_node_id(i.id).expect_owner() }, |
fc512014 XL |
734 | ident: i.ident, |
735 | span: i.span, | |
736 | vis: self.lower_visibility(&i.vis, Some(i.id)), | |
416331ca XL |
737 | } |
738 | } | |
739 | ||
dfeec247 | 740 | fn lower_variant(&mut self, v: &Variant) -> hir::Variant<'hir> { |
6a06907d XL |
741 | let id = self.lower_node_id(v.id); |
742 | self.lower_attrs(id, &v.attrs); | |
e1599b0c | 743 | hir::Variant { |
6a06907d XL |
744 | id, |
745 | data: self.lower_variant_data(id, &v.data), | |
e1599b0c | 746 | disr_expr: v.disr_expr.as_ref().map(|e| self.lower_anon_const(e)), |
e1599b0c | 747 | ident: v.ident, |
416331ca XL |
748 | span: v.span, |
749 | } | |
750 | } | |
751 | ||
6a06907d XL |
752 | fn lower_variant_data( |
753 | &mut self, | |
754 | parent_id: hir::HirId, | |
755 | vdata: &VariantData, | |
756 | ) -> hir::VariantData<'hir> { | |
416331ca XL |
757 | match *vdata { |
758 | VariantData::Struct(ref fields, recovered) => hir::VariantData::Struct( | |
dfeec247 | 759 | self.arena |
6a06907d | 760 | .alloc_from_iter(fields.iter().enumerate().map(|f| self.lower_field_def(f))), |
416331ca XL |
761 | recovered, |
762 | ), | |
6a06907d XL |
763 | VariantData::Tuple(ref fields, id) => { |
764 | let ctor_id = self.lower_node_id(id); | |
765 | self.alias_attrs(ctor_id, parent_id); | |
766 | hir::VariantData::Tuple( | |
767 | self.arena.alloc_from_iter( | |
768 | fields.iter().enumerate().map(|f| self.lower_field_def(f)), | |
769 | ), | |
770 | ctor_id, | |
771 | ) | |
772 | } | |
773 | VariantData::Unit(id) => { | |
774 | let ctor_id = self.lower_node_id(id); | |
775 | self.alias_attrs(ctor_id, parent_id); | |
776 | hir::VariantData::Unit(ctor_id) | |
777 | } | |
416331ca XL |
778 | } |
779 | } | |
780 | ||
17df50a5 XL |
781 | pub(super) fn lower_field_def( |
782 | &mut self, | |
783 | (index, f): (usize, &FieldDef), | |
784 | ) -> hir::FieldDef<'hir> { | |
e74abb32 | 785 | let ty = if let TyKind::Path(ref qself, ref path) = f.ty.kind { |
416331ca XL |
786 | let t = self.lower_path_ty( |
787 | &f.ty, | |
788 | qself, | |
789 | path, | |
790 | ParamMode::ExplicitNamed, // no `'_` in declarations (Issue #61124) | |
dfeec247 | 791 | ImplTraitContext::disallowed(), |
416331ca | 792 | ); |
dfeec247 | 793 | self.arena.alloc(t) |
416331ca XL |
794 | } else { |
795 | self.lower_ty(&f.ty, ImplTraitContext::disallowed()) | |
796 | }; | |
6a06907d XL |
797 | let hir_id = self.lower_node_id(f.id); |
798 | self.lower_attrs(hir_id, &f.attrs); | |
799 | hir::FieldDef { | |
416331ca | 800 | span: f.span, |
6a06907d | 801 | hir_id, |
416331ca XL |
802 | ident: match f.ident { |
803 | Some(ident) => ident, | |
804 | // FIXME(jseyfried): positional field hygiene. | |
805 | None => Ident::new(sym::integer(index), f.span), | |
806 | }, | |
807 | vis: self.lower_visibility(&f.vis, None), | |
808 | ty, | |
416331ca XL |
809 | } |
810 | } | |
811 | ||
dfeec247 | 812 | fn lower_trait_item(&mut self, i: &AssocItem) -> hir::TraitItem<'hir> { |
6a06907d XL |
813 | let hir_id = self.lower_node_id(i.id); |
814 | let trait_item_def_id = hir_id.expect_owner(); | |
416331ca | 815 | |
e74abb32 | 816 | let (generics, kind) = match i.kind { |
74b04a01 | 817 | AssocItemKind::Const(_, ref ty, ref default) => { |
dfeec247 | 818 | let ty = self.lower_ty(ty, ImplTraitContext::disallowed()); |
74b04a01 XL |
819 | let body = default.as_ref().map(|x| self.lower_const_body(i.span, Some(x))); |
820 | (hir::Generics::empty(), hir::TraitItemKind::Const(ty, body)) | |
dfeec247 | 821 | } |
5869c6ff | 822 | AssocItemKind::Fn(box FnKind(_, ref sig, ref generics, None)) => { |
e1599b0c | 823 | let names = self.lower_fn_params_to_names(&sig.decl); |
dfeec247 | 824 | let (generics, sig) = |
5869c6ff | 825 | self.lower_method_sig(generics, sig, trait_item_def_id, false, None, i.id); |
ba9703b0 | 826 | (generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Required(names))) |
416331ca | 827 | } |
5869c6ff | 828 | AssocItemKind::Fn(box FnKind(_, ref sig, ref generics, Some(ref body))) => { |
cdc7bbd5 XL |
829 | let asyncness = sig.header.asyncness; |
830 | let body_id = | |
831 | self.lower_maybe_async_body(i.span, &sig.decl, asyncness, Some(&body)); | |
832 | let (generics, sig) = self.lower_method_sig( | |
833 | generics, | |
834 | sig, | |
835 | trait_item_def_id, | |
836 | false, | |
837 | asyncness.opt_return_id(), | |
838 | i.id, | |
839 | ); | |
ba9703b0 | 840 | (generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Provided(body_id))) |
416331ca | 841 | } |
5869c6ff | 842 | AssocItemKind::TyAlias(box TyAliasKind(_, ref generics, ref bounds, ref default)) => { |
dfeec247 | 843 | let ty = default.as_ref().map(|x| self.lower_ty(x, ImplTraitContext::disallowed())); |
74b04a01 | 844 | let generics = self.lower_generics(generics, ImplTraitContext::disallowed()); |
e74abb32 | 845 | let kind = hir::TraitItemKind::Type( |
416331ca | 846 | self.lower_param_bounds(bounds, ImplTraitContext::disallowed()), |
dfeec247 | 847 | ty, |
416331ca XL |
848 | ); |
849 | ||
e74abb32 | 850 | (generics, kind) |
dfeec247 | 851 | } |
ba9703b0 | 852 | AssocItemKind::MacCall(..) => panic!("macro item shouldn't exist at this point"), |
416331ca XL |
853 | }; |
854 | ||
6a06907d XL |
855 | self.lower_attrs(hir_id, &i.attrs); |
856 | hir::TraitItem { def_id: trait_item_def_id, ident: i.ident, generics, kind, span: i.span } | |
416331ca XL |
857 | } |
858 | ||
dfeec247 | 859 | fn lower_trait_item_ref(&mut self, i: &AssocItem) -> hir::TraitItemRef { |
74b04a01 XL |
860 | let (kind, has_default) = match &i.kind { |
861 | AssocItemKind::Const(_, _, default) => (hir::AssocItemKind::Const, default.is_some()), | |
5869c6ff | 862 | AssocItemKind::TyAlias(box TyAliasKind(_, _, _, default)) => { |
74b04a01 XL |
863 | (hir::AssocItemKind::Type, default.is_some()) |
864 | } | |
5869c6ff | 865 | AssocItemKind::Fn(box FnKind(_, sig, _, default)) => { |
ba9703b0 | 866 | (hir::AssocItemKind::Fn { has_self: sig.decl.has_self() }, default.is_some()) |
416331ca | 867 | } |
ba9703b0 | 868 | AssocItemKind::MacCall(..) => unimplemented!(), |
416331ca | 869 | }; |
6a06907d | 870 | let id = hir::TraitItemId { def_id: self.lower_node_id(i.id).expect_owner() }; |
74b04a01 XL |
871 | let defaultness = hir::Defaultness::Default { has_value: has_default }; |
872 | hir::TraitItemRef { id, ident: i.ident, span: i.span, defaultness, kind } | |
416331ca XL |
873 | } |
874 | ||
dfeec247 | 875 | /// Construct `ExprKind::Err` for the given `span`. |
ba9703b0 | 876 | crate fn expr_err(&mut self, span: Span) -> hir::Expr<'hir> { |
dfeec247 XL |
877 | self.expr(span, hir::ExprKind::Err, AttrVec::new()) |
878 | } | |
879 | ||
880 | fn lower_impl_item(&mut self, i: &AssocItem) -> hir::ImplItem<'hir> { | |
f035d41b | 881 | let impl_item_def_id = self.resolver.local_def_id(i.id); |
416331ca | 882 | |
74b04a01 XL |
883 | let (generics, kind) = match &i.kind { |
884 | AssocItemKind::Const(_, ty, expr) => { | |
dfeec247 XL |
885 | let ty = self.lower_ty(ty, ImplTraitContext::disallowed()); |
886 | ( | |
74b04a01 | 887 | hir::Generics::empty(), |
dfeec247 XL |
888 | hir::ImplItemKind::Const(ty, self.lower_const_body(i.span, expr.as_deref())), |
889 | ) | |
890 | } | |
5869c6ff | 891 | AssocItemKind::Fn(box FnKind(_, sig, generics, body)) => { |
416331ca | 892 | self.current_item = Some(i.span); |
74b04a01 XL |
893 | let asyncness = sig.header.asyncness; |
894 | let body_id = | |
895 | self.lower_maybe_async_body(i.span, &sig.decl, asyncness, body.as_deref()); | |
416331ca XL |
896 | let impl_trait_return_allow = !self.is_in_trait_impl; |
897 | let (generics, sig) = self.lower_method_sig( | |
74b04a01 | 898 | generics, |
416331ca XL |
899 | sig, |
900 | impl_item_def_id, | |
901 | impl_trait_return_allow, | |
74b04a01 | 902 | asyncness.opt_return_id(), |
5869c6ff | 903 | i.id, |
416331ca XL |
904 | ); |
905 | ||
ba9703b0 | 906 | (generics, hir::ImplItemKind::Fn(sig, body_id)) |
416331ca | 907 | } |
5869c6ff | 908 | AssocItemKind::TyAlias(box TyAliasKind(_, generics, _, ty)) => { |
74b04a01 | 909 | let generics = self.lower_generics(generics, ImplTraitContext::disallowed()); |
dfeec247 | 910 | let kind = match ty { |
60c5eb7d | 911 | None => { |
dfeec247 | 912 | let ty = self.arena.alloc(self.ty(i.span, hir::TyKind::Err)); |
60c5eb7d XL |
913 | hir::ImplItemKind::TyAlias(ty) |
914 | } | |
f035d41b XL |
915 | Some(ty) => { |
916 | let ty = self.lower_ty( | |
917 | ty, | |
136023e0 | 918 | ImplTraitContext::TypeAliasesOpaqueTy { |
f035d41b | 919 | capturable_lifetimes: &mut FxHashSet::default(), |
f035d41b XL |
920 | }, |
921 | ); | |
922 | hir::ImplItemKind::TyAlias(ty) | |
923 | } | |
60c5eb7d XL |
924 | }; |
925 | (generics, kind) | |
dfeec247 | 926 | } |
ba9703b0 | 927 | AssocItemKind::MacCall(..) => panic!("`TyMac` should have been expanded by now"), |
416331ca XL |
928 | }; |
929 | ||
ba9703b0 XL |
930 | // Since `default impl` is not yet implemented, this is always true in impls. |
931 | let has_value = true; | |
932 | let (defaultness, _) = self.lower_defaultness(i.kind.defaultness(), has_value); | |
6a06907d XL |
933 | let hir_id = self.lower_node_id(i.id); |
934 | self.lower_attrs(hir_id, &i.attrs); | |
416331ca | 935 | hir::ImplItem { |
6a06907d | 936 | def_id: hir_id.expect_owner(), |
416331ca | 937 | ident: i.ident, |
416331ca XL |
938 | generics, |
939 | vis: self.lower_visibility(&i.vis, None), | |
ba9703b0 | 940 | defaultness, |
e74abb32 | 941 | kind, |
416331ca XL |
942 | span: i.span, |
943 | } | |
416331ca XL |
944 | } |
945 | ||
dfeec247 | 946 | fn lower_impl_item_ref(&mut self, i: &AssocItem) -> hir::ImplItemRef<'hir> { |
ba9703b0 XL |
947 | // Since `default impl` is not yet implemented, this is always true in impls. |
948 | let has_value = true; | |
949 | let (defaultness, _) = self.lower_defaultness(i.kind.defaultness(), has_value); | |
416331ca | 950 | hir::ImplItemRef { |
6a06907d | 951 | id: hir::ImplItemId { def_id: self.lower_node_id(i.id).expect_owner() }, |
416331ca XL |
952 | ident: i.ident, |
953 | span: i.span, | |
954 | vis: self.lower_visibility(&i.vis, Some(i.id)), | |
ba9703b0 | 955 | defaultness, |
60c5eb7d | 956 | kind: match &i.kind { |
dfeec247 | 957 | AssocItemKind::Const(..) => hir::AssocItemKind::Const, |
f035d41b | 958 | AssocItemKind::TyAlias(..) => hir::AssocItemKind::Type, |
5869c6ff | 959 | AssocItemKind::Fn(box FnKind(_, sig, ..)) => { |
ba9703b0 | 960 | hir::AssocItemKind::Fn { has_self: sig.decl.has_self() } |
dfeec247 | 961 | } |
ba9703b0 | 962 | AssocItemKind::MacCall(..) => unimplemented!(), |
416331ca XL |
963 | }, |
964 | } | |
416331ca XL |
965 | } |
966 | ||
967 | /// If an `explicit_owner` is given, this method allocates the `HirId` in | |
968 | /// the address space of that item instead of the item currently being | |
969 | /// lowered. This can happen during `lower_impl_item_ref()` where we need to | |
970 | /// lower a `Visibility` value although we haven't lowered the owning | |
971 | /// `ImplItem` in question yet. | |
972 | fn lower_visibility( | |
973 | &mut self, | |
974 | v: &Visibility, | |
975 | explicit_owner: Option<NodeId>, | |
dfeec247 | 976 | ) -> hir::Visibility<'hir> { |
1b1a35ee | 977 | let node = match v.kind { |
416331ca XL |
978 | VisibilityKind::Public => hir::VisibilityKind::Public, |
979 | VisibilityKind::Crate(sugar) => hir::VisibilityKind::Crate(sugar), | |
980 | VisibilityKind::Restricted { ref path, id } => { | |
981 | debug!("lower_visibility: restricted path id = {:?}", id); | |
982 | let lowered_id = if let Some(owner) = explicit_owner { | |
983 | self.lower_node_id_with_owner(id, owner) | |
984 | } else { | |
985 | self.lower_node_id(id) | |
986 | }; | |
987 | let res = self.expect_full_res(id); | |
988 | let res = self.lower_res(res); | |
989 | hir::VisibilityKind::Restricted { | |
dfeec247 | 990 | path: self.lower_path_extra(res, path, ParamMode::Explicit, explicit_owner), |
416331ca XL |
991 | hir_id: lowered_id, |
992 | } | |
dfeec247 | 993 | } |
416331ca XL |
994 | VisibilityKind::Inherited => hir::VisibilityKind::Inherited, |
995 | }; | |
996 | respan(v.span, node) | |
997 | } | |
998 | ||
ba9703b0 XL |
999 | fn lower_defaultness( |
1000 | &self, | |
1001 | d: Defaultness, | |
1002 | has_value: bool, | |
1003 | ) -> (hir::Defaultness, Option<Span>) { | |
416331ca | 1004 | match d { |
ba9703b0 | 1005 | Defaultness::Default(sp) => (hir::Defaultness::Default { has_value }, Some(sp)), |
416331ca XL |
1006 | Defaultness::Final => { |
1007 | assert!(has_value); | |
ba9703b0 | 1008 | (hir::Defaultness::Final, None) |
416331ca XL |
1009 | } |
1010 | } | |
1011 | } | |
1012 | ||
dfeec247 XL |
1013 | fn record_body( |
1014 | &mut self, | |
1015 | params: &'hir [hir::Param<'hir>], | |
1016 | value: hir::Expr<'hir>, | |
1017 | ) -> hir::BodyId { | |
1018 | let body = hir::Body { generator_kind: self.generator_kind, params, value }; | |
416331ca XL |
1019 | let id = body.id(); |
1020 | self.bodies.insert(id, body); | |
1021 | id | |
1022 | } | |
1023 | ||
ba9703b0 | 1024 | pub(super) fn lower_body( |
416331ca | 1025 | &mut self, |
dfeec247 | 1026 | f: impl FnOnce(&mut Self) -> (&'hir [hir::Param<'hir>], hir::Expr<'hir>), |
416331ca XL |
1027 | ) -> hir::BodyId { |
1028 | let prev_gen_kind = self.generator_kind.take(); | |
ba9703b0 | 1029 | let task_context = self.task_context.take(); |
e1599b0c XL |
1030 | let (parameters, result) = f(self); |
1031 | let body_id = self.record_body(parameters, result); | |
ba9703b0 | 1032 | self.task_context = task_context; |
416331ca XL |
1033 | self.generator_kind = prev_gen_kind; |
1034 | body_id | |
1035 | } | |
1036 | ||
dfeec247 | 1037 | fn lower_param(&mut self, param: &Param) -> hir::Param<'hir> { |
6a06907d XL |
1038 | let hir_id = self.lower_node_id(param.id); |
1039 | self.lower_attrs(hir_id, ¶m.attrs); | |
e1599b0c | 1040 | hir::Param { |
6a06907d | 1041 | hir_id, |
e1599b0c | 1042 | pat: self.lower_pat(¶m.pat), |
3dfed10e | 1043 | ty_span: param.ty.span, |
e1599b0c | 1044 | span: param.span, |
416331ca XL |
1045 | } |
1046 | } | |
1047 | ||
1048 | pub(super) fn lower_fn_body( | |
1049 | &mut self, | |
1050 | decl: &FnDecl, | |
dfeec247 | 1051 | body: impl FnOnce(&mut Self) -> hir::Expr<'hir>, |
416331ca | 1052 | ) -> hir::BodyId { |
dfeec247 XL |
1053 | self.lower_body(|this| { |
1054 | ( | |
1055 | this.arena.alloc_from_iter(decl.inputs.iter().map(|x| this.lower_param(x))), | |
1056 | body(this), | |
1057 | ) | |
1058 | }) | |
416331ca XL |
1059 | } |
1060 | ||
dfeec247 XL |
1061 | fn lower_fn_body_block( |
1062 | &mut self, | |
1063 | span: Span, | |
1064 | decl: &FnDecl, | |
1065 | body: Option<&Block>, | |
1066 | ) -> hir::BodyId { | |
1067 | self.lower_fn_body(decl, |this| this.lower_block_expr_opt(span, body)) | |
416331ca XL |
1068 | } |
1069 | ||
dfeec247 XL |
1070 | fn lower_block_expr_opt(&mut self, span: Span, block: Option<&Block>) -> hir::Expr<'hir> { |
1071 | match block { | |
1072 | Some(block) => self.lower_block_expr(block), | |
1073 | None => self.expr_err(span), | |
1074 | } | |
1075 | } | |
1076 | ||
1077 | pub(super) fn lower_const_body(&mut self, span: Span, expr: Option<&Expr>) -> hir::BodyId { | |
1078 | self.lower_body(|this| { | |
1079 | ( | |
1080 | &[], | |
1081 | match expr { | |
1082 | Some(expr) => this.lower_expr_mut(expr), | |
1083 | None => this.expr_err(span), | |
1084 | }, | |
1085 | ) | |
1086 | }) | |
416331ca XL |
1087 | } |
1088 | ||
1089 | fn lower_maybe_async_body( | |
1090 | &mut self, | |
dfeec247 | 1091 | span: Span, |
416331ca | 1092 | decl: &FnDecl, |
74b04a01 | 1093 | asyncness: Async, |
dfeec247 | 1094 | body: Option<&Block>, |
416331ca XL |
1095 | ) -> hir::BodyId { |
1096 | let closure_id = match asyncness { | |
74b04a01 XL |
1097 | Async::Yes { closure_id, .. } => closure_id, |
1098 | Async::No => return self.lower_fn_body_block(span, decl, body), | |
416331ca XL |
1099 | }; |
1100 | ||
1101 | self.lower_body(|this| { | |
dfeec247 XL |
1102 | let mut parameters: Vec<hir::Param<'_>> = Vec::new(); |
1103 | let mut statements: Vec<hir::Stmt<'_>> = Vec::new(); | |
416331ca | 1104 | |
e1599b0c | 1105 | // Async function parameters are lowered into the closure body so that they are |
416331ca XL |
1106 | // captured and so that the drop order matches the equivalent non-async functions. |
1107 | // | |
1108 | // from: | |
1109 | // | |
1110 | // async fn foo(<pattern>: <ty>, <pattern>: <ty>, <pattern>: <ty>) { | |
e1599b0c | 1111 | // <body> |
416331ca XL |
1112 | // } |
1113 | // | |
1114 | // into: | |
1115 | // | |
1116 | // fn foo(__arg0: <ty>, __arg1: <ty>, __arg2: <ty>) { | |
1117 | // async move { | |
1118 | // let __arg2 = __arg2; | |
1119 | // let <pattern> = __arg2; | |
1120 | // let __arg1 = __arg1; | |
1121 | // let <pattern> = __arg1; | |
1122 | // let __arg0 = __arg0; | |
1123 | // let <pattern> = __arg0; | |
e1599b0c | 1124 | // drop-temps { <body> } // see comments later in fn for details |
416331ca XL |
1125 | // } |
1126 | // } | |
1127 | // | |
1128 | // If `<pattern>` is a simple ident, then it is lowered to a single | |
1129 | // `let <pattern> = <pattern>;` statement as an optimization. | |
e1599b0c XL |
1130 | // |
1131 | // Note that the body is embedded in `drop-temps`; an | |
1132 | // equivalent desugaring would be `return { <body> | |
1133 | // };`. The key point is that we wish to drop all the | |
1134 | // let-bound variables and temporaries created in the body | |
1135 | // (and its tail expression!) before we drop the | |
1136 | // parameters (c.f. rust-lang/rust#64512). | |
1137 | for (index, parameter) in decl.inputs.iter().enumerate() { | |
1138 | let parameter = this.lower_param(parameter); | |
1139 | let span = parameter.pat.span; | |
416331ca XL |
1140 | |
1141 | // Check if this is a binding pattern, if so, we can optimize and avoid adding a | |
e1599b0c | 1142 | // `let <pat> = __argN;` statement. In this case, we do not rename the parameter. |
e74abb32 | 1143 | let (ident, is_simple_parameter) = match parameter.pat.kind { |
29967ef6 XL |
1144 | hir::PatKind::Binding( |
1145 | hir::BindingAnnotation::Unannotated | hir::BindingAnnotation::Mutable, | |
1146 | _, | |
1147 | ident, | |
1148 | _, | |
1149 | ) => (ident, true), | |
1150 | // For `ref mut` or wildcard arguments, we can't reuse the binding, but | |
1151 | // we can keep the same name for the parameter. | |
1152 | // This lets rustdoc render it correctly in documentation. | |
1153 | hir::PatKind::Binding(_, _, ident, _) => (ident, false), | |
1154 | hir::PatKind::Wild => { | |
1155 | (Ident::with_dummy_span(rustc_span::symbol::kw::Underscore), false) | |
dfeec247 | 1156 | } |
416331ca XL |
1157 | _ => { |
1158 | // Replace the ident for bindings that aren't simple. | |
1159 | let name = format!("__arg{}", index); | |
1160 | let ident = Ident::from_str(&name); | |
1161 | ||
1162 | (ident, false) | |
dfeec247 | 1163 | } |
416331ca XL |
1164 | }; |
1165 | ||
dfeec247 | 1166 | let desugared_span = this.mark_span_with_reason(DesugaringKind::Async, span, None); |
416331ca | 1167 | |
e1599b0c | 1168 | // Construct a parameter representing `__argN: <ty>` to replace the parameter of the |
416331ca XL |
1169 | // async function. |
1170 | // | |
e1599b0c XL |
1171 | // If this is the simple case, this parameter will end up being the same as the |
1172 | // original parameter, but with a different pattern id. | |
6a06907d | 1173 | let stmt_attrs = this.attrs.get(¶meter.hir_id).copied(); |
e1599b0c XL |
1174 | let (new_parameter_pat, new_parameter_id) = this.pat_ident(desugared_span, ident); |
1175 | let new_parameter = hir::Param { | |
e1599b0c XL |
1176 | hir_id: parameter.hir_id, |
1177 | pat: new_parameter_pat, | |
3dfed10e | 1178 | ty_span: parameter.ty_span, |
e1599b0c | 1179 | span: parameter.span, |
416331ca XL |
1180 | }; |
1181 | ||
e1599b0c | 1182 | if is_simple_parameter { |
416331ca XL |
1183 | // If this is the simple case, then we only insert one statement that is |
1184 | // `let <pat> = <pat>;`. We re-use the original argument's pattern so that | |
1185 | // `HirId`s are densely assigned. | |
e1599b0c | 1186 | let expr = this.expr_ident(desugared_span, ident, new_parameter_id); |
416331ca XL |
1187 | let stmt = this.stmt_let_pat( |
1188 | stmt_attrs, | |
1189 | desugared_span, | |
dfeec247 | 1190 | Some(expr), |
e1599b0c | 1191 | parameter.pat, |
dfeec247 | 1192 | hir::LocalSource::AsyncFn, |
416331ca XL |
1193 | ); |
1194 | statements.push(stmt); | |
1195 | } else { | |
1196 | // If this is not the simple case, then we construct two statements: | |
1197 | // | |
1198 | // ``` | |
1199 | // let __argN = __argN; | |
1200 | // let <pat> = __argN; | |
1201 | // ``` | |
1202 | // | |
e1599b0c | 1203 | // The first statement moves the parameter into the closure and thus ensures |
416331ca XL |
1204 | // that the drop order is correct. |
1205 | // | |
1206 | // The second statement creates the bindings that the user wrote. | |
1207 | ||
1208 | // Construct the `let mut __argN = __argN;` statement. It must be a mut binding | |
1209 | // because the user may have specified a `ref mut` binding in the next | |
1210 | // statement. | |
1211 | let (move_pat, move_id) = this.pat_ident_binding_mode( | |
dfeec247 XL |
1212 | desugared_span, |
1213 | ident, | |
1214 | hir::BindingAnnotation::Mutable, | |
1215 | ); | |
e1599b0c | 1216 | let move_expr = this.expr_ident(desugared_span, ident, new_parameter_id); |
416331ca | 1217 | let move_stmt = this.stmt_let_pat( |
6a06907d | 1218 | None, |
416331ca | 1219 | desugared_span, |
dfeec247 | 1220 | Some(move_expr), |
416331ca | 1221 | move_pat, |
dfeec247 | 1222 | hir::LocalSource::AsyncFn, |
416331ca XL |
1223 | ); |
1224 | ||
1225 | // Construct the `let <pat> = __argN;` statement. We re-use the original | |
e1599b0c | 1226 | // parameter's pattern so that `HirId`s are densely assigned. |
416331ca XL |
1227 | let pattern_expr = this.expr_ident(desugared_span, ident, move_id); |
1228 | let pattern_stmt = this.stmt_let_pat( | |
1229 | stmt_attrs, | |
1230 | desugared_span, | |
dfeec247 | 1231 | Some(pattern_expr), |
e1599b0c | 1232 | parameter.pat, |
dfeec247 | 1233 | hir::LocalSource::AsyncFn, |
416331ca XL |
1234 | ); |
1235 | ||
1236 | statements.push(move_stmt); | |
1237 | statements.push(pattern_stmt); | |
1238 | }; | |
1239 | ||
e1599b0c | 1240 | parameters.push(new_parameter); |
416331ca XL |
1241 | } |
1242 | ||
dfeec247 | 1243 | let body_span = body.map_or(span, |b| b.span); |
416331ca | 1244 | let async_expr = this.make_async_expr( |
e74abb32 XL |
1245 | CaptureBy::Value, |
1246 | closure_id, | |
1247 | None, | |
dfeec247 | 1248 | body_span, |
e74abb32 | 1249 | hir::AsyncGeneratorKind::Fn, |
416331ca | 1250 | |this| { |
e1599b0c | 1251 | // Create a block from the user's function body: |
dfeec247 | 1252 | let user_body = this.lower_block_expr_opt(body_span, body); |
e1599b0c XL |
1253 | |
1254 | // Transform into `drop-temps { <user-body> }`, an expression: | |
dfeec247 XL |
1255 | let desugared_span = |
1256 | this.mark_span_with_reason(DesugaringKind::Async, user_body.span, None); | |
e1599b0c XL |
1257 | let user_body = this.expr_drop_temps( |
1258 | desugared_span, | |
dfeec247 XL |
1259 | this.arena.alloc(user_body), |
1260 | AttrVec::new(), | |
e1599b0c XL |
1261 | ); |
1262 | ||
1263 | // As noted above, create the final block like | |
1264 | // | |
1265 | // ``` | |
1266 | // { | |
1267 | // let $param_pattern = $raw_param; | |
1268 | // ... | |
1269 | // drop-temps { <user-body> } | |
1270 | // } | |
1271 | // ``` | |
1272 | let body = this.block_all( | |
1273 | desugared_span, | |
dfeec247 XL |
1274 | this.arena.alloc_from_iter(statements), |
1275 | Some(user_body), | |
e1599b0c | 1276 | ); |
dfeec247 XL |
1277 | |
1278 | this.expr_block(body, AttrVec::new()) | |
1279 | }, | |
1280 | ); | |
1281 | ||
1282 | ( | |
1283 | this.arena.alloc_from_iter(parameters), | |
1284 | this.expr(body_span, async_expr, AttrVec::new()), | |
1285 | ) | |
416331ca XL |
1286 | }) |
1287 | } | |
1288 | ||
1289 | fn lower_method_sig( | |
1290 | &mut self, | |
1291 | generics: &Generics, | |
60c5eb7d | 1292 | sig: &FnSig, |
ba9703b0 | 1293 | fn_def_id: LocalDefId, |
416331ca XL |
1294 | impl_trait_return_allow: bool, |
1295 | is_async: Option<NodeId>, | |
5869c6ff | 1296 | id: NodeId, |
dfeec247 | 1297 | ) -> (hir::Generics<'hir>, hir::FnSig<'hir>) { |
5869c6ff | 1298 | let header = self.lower_fn_header(sig.header, sig.span, id); |
416331ca XL |
1299 | let (generics, decl) = self.add_in_band_defs( |
1300 | generics, | |
1301 | fn_def_id, | |
1302 | AnonymousLifetimeMode::PassThrough, | |
dfeec247 XL |
1303 | |this, idty| { |
1304 | this.lower_fn_decl( | |
1305 | &sig.decl, | |
ba9703b0 | 1306 | Some((fn_def_id.to_def_id(), idty)), |
dfeec247 XL |
1307 | impl_trait_return_allow, |
1308 | is_async, | |
1309 | ) | |
1310 | }, | |
416331ca | 1311 | ); |
3dfed10e | 1312 | (generics, hir::FnSig { header, decl, span: sig.span }) |
416331ca XL |
1313 | } |
1314 | ||
5869c6ff | 1315 | fn lower_fn_header(&mut self, h: FnHeader, span: Span, id: NodeId) -> hir::FnHeader { |
416331ca | 1316 | hir::FnHeader { |
74b04a01 XL |
1317 | unsafety: self.lower_unsafety(h.unsafety), |
1318 | asyncness: self.lower_asyncness(h.asyncness), | |
1319 | constness: self.lower_constness(h.constness), | |
5869c6ff | 1320 | abi: self.lower_extern(h.ext, span, id), |
416331ca XL |
1321 | } |
1322 | } | |
1323 | ||
60c5eb7d XL |
1324 | pub(super) fn lower_abi(&mut self, abi: StrLit) -> abi::Abi { |
1325 | abi::lookup(&abi.symbol_unescaped.as_str()).unwrap_or_else(|| { | |
1326 | self.error_on_invalid_abi(abi); | |
1327 | abi::Abi::Rust | |
1328 | }) | |
416331ca XL |
1329 | } |
1330 | ||
5869c6ff | 1331 | pub(super) fn lower_extern(&mut self, ext: Extern, span: Span, id: NodeId) -> abi::Abi { |
60c5eb7d XL |
1332 | match ext { |
1333 | Extern::None => abi::Abi::Rust, | |
5869c6ff | 1334 | Extern::Implicit => { |
6a06907d XL |
1335 | self.maybe_lint_missing_abi(span, id, abi::Abi::C { unwind: false }); |
1336 | abi::Abi::C { unwind: false } | |
5869c6ff | 1337 | } |
60c5eb7d | 1338 | Extern::Explicit(abi) => self.lower_abi(abi), |
416331ca XL |
1339 | } |
1340 | } | |
1341 | ||
60c5eb7d | 1342 | fn error_on_invalid_abi(&self, abi: StrLit) { |
dfeec247 XL |
1343 | struct_span_err!(self.sess, abi.span, E0703, "invalid ABI: found `{}`", abi.symbol) |
1344 | .span_label(abi.span, "invalid ABI") | |
1345 | .help(&format!("valid ABIs: {}", abi::all_names().join(", "))) | |
1346 | .emit(); | |
60c5eb7d XL |
1347 | } |
1348 | ||
74b04a01 | 1349 | fn lower_asyncness(&mut self, a: Async) -> hir::IsAsync { |
416331ca | 1350 | match a { |
74b04a01 XL |
1351 | Async::Yes { .. } => hir::IsAsync::Async, |
1352 | Async::No => hir::IsAsync::NotAsync, | |
1353 | } | |
1354 | } | |
1355 | ||
1356 | fn lower_constness(&mut self, c: Const) -> hir::Constness { | |
1357 | match c { | |
1358 | Const::Yes(_) => hir::Constness::Const, | |
1359 | Const::No => hir::Constness::NotConst, | |
1360 | } | |
1361 | } | |
1362 | ||
1363 | pub(super) fn lower_unsafety(&mut self, u: Unsafe) -> hir::Unsafety { | |
1364 | match u { | |
1365 | Unsafe::Yes(_) => hir::Unsafety::Unsafe, | |
1366 | Unsafe::No => hir::Unsafety::Normal, | |
416331ca XL |
1367 | } |
1368 | } | |
1369 | ||
dfeec247 | 1370 | pub(super) fn lower_generics_mut( |
416331ca XL |
1371 | &mut self, |
1372 | generics: &Generics, | |
dfeec247 XL |
1373 | itctx: ImplTraitContext<'_, 'hir>, |
1374 | ) -> GenericsCtor<'hir> { | |
416331ca | 1375 | // Collect `?Trait` bounds in where clause and move them to parameter definitions. |
416331ca XL |
1376 | let mut add_bounds: NodeMap<Vec<_>> = Default::default(); |
1377 | for pred in &generics.where_clause.predicates { | |
1378 | if let WherePredicate::BoundPredicate(ref bound_pred) = *pred { | |
1379 | 'next_bound: for bound in &bound_pred.bounds { | |
1380 | if let GenericBound::Trait(_, TraitBoundModifier::Maybe) = *bound { | |
416331ca | 1381 | // Check if the where clause type is a plain type parameter. |
136023e0 XL |
1382 | match self |
1383 | .resolver | |
1384 | .get_partial_res(bound_pred.bounded_ty.id) | |
1385 | .map(|d| (d.base_res(), d.unresolved_segments())) | |
1386 | { | |
1387 | Some((Res::Def(DefKind::TyParam, def_id), 0)) | |
1388 | if bound_pred.bound_generic_params.is_empty() => | |
416331ca | 1389 | { |
136023e0 XL |
1390 | for param in &generics.params { |
1391 | if def_id == self.resolver.local_def_id(param.id).to_def_id() { | |
1392 | add_bounds.entry(param.id).or_default().push(bound.clone()); | |
1393 | continue 'next_bound; | |
416331ca XL |
1394 | } |
1395 | } | |
416331ca | 1396 | } |
136023e0 | 1397 | _ => {} |
416331ca | 1398 | } |
136023e0 XL |
1399 | self.diagnostic().span_err( |
1400 | bound_pred.bounded_ty.span, | |
1401 | "`?Trait` bounds are only permitted at the \ | |
1402 | point where a type parameter is declared", | |
1403 | ); | |
416331ca XL |
1404 | } |
1405 | } | |
1406 | } | |
1407 | } | |
1408 | ||
dfeec247 XL |
1409 | GenericsCtor { |
1410 | params: self.lower_generic_params_mut(&generics.params, &add_bounds, itctx).collect(), | |
416331ca XL |
1411 | where_clause: self.lower_where_clause(&generics.where_clause), |
1412 | span: generics.span, | |
1413 | } | |
1414 | } | |
1415 | ||
dfeec247 XL |
1416 | pub(super) fn lower_generics( |
1417 | &mut self, | |
1418 | generics: &Generics, | |
1419 | itctx: ImplTraitContext<'_, 'hir>, | |
1420 | ) -> hir::Generics<'hir> { | |
1421 | let generics_ctor = self.lower_generics_mut(generics, itctx); | |
1422 | generics_ctor.into_generics(self.arena) | |
1423 | } | |
1424 | ||
1425 | fn lower_where_clause(&mut self, wc: &WhereClause) -> hir::WhereClause<'hir> { | |
1426 | self.with_anonymous_lifetime_mode(AnonymousLifetimeMode::ReportError, |this| { | |
1427 | hir::WhereClause { | |
1428 | predicates: this.arena.alloc_from_iter( | |
1429 | wc.predicates.iter().map(|predicate| this.lower_where_predicate(predicate)), | |
1430 | ), | |
1431 | span: wc.span, | |
1432 | } | |
1433 | }) | |
416331ca XL |
1434 | } |
1435 | ||
dfeec247 | 1436 | fn lower_where_predicate(&mut self, pred: &WherePredicate) -> hir::WherePredicate<'hir> { |
416331ca XL |
1437 | match *pred { |
1438 | WherePredicate::BoundPredicate(WhereBoundPredicate { | |
1439 | ref bound_generic_params, | |
1440 | ref bounded_ty, | |
1441 | ref bounds, | |
1442 | span, | |
1443 | }) => { | |
dfeec247 XL |
1444 | self.with_in_scope_lifetime_defs(&bound_generic_params, |this| { |
1445 | hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate { | |
1446 | bound_generic_params: this.lower_generic_params( | |
1447 | bound_generic_params, | |
1448 | &NodeMap::default(), | |
1449 | ImplTraitContext::disallowed(), | |
1450 | ), | |
1451 | bounded_ty: this.lower_ty(bounded_ty, ImplTraitContext::disallowed()), | |
1452 | bounds: this.arena.alloc_from_iter(bounds.iter().filter_map(|bound| { | |
1453 | match *bound { | |
1454 | // Ignore `?Trait` bounds. | |
1455 | // They were copied into type parameters already. | |
1456 | GenericBound::Trait(_, TraitBoundModifier::Maybe) => None, | |
1457 | _ => Some( | |
1458 | this.lower_param_bound(bound, ImplTraitContext::disallowed()), | |
1459 | ), | |
1460 | } | |
1461 | })), | |
1462 | span, | |
1463 | }) | |
1464 | }) | |
416331ca XL |
1465 | } |
1466 | WherePredicate::RegionPredicate(WhereRegionPredicate { | |
1467 | ref lifetime, | |
1468 | ref bounds, | |
1469 | span, | |
1470 | }) => hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate { | |
1471 | span, | |
1472 | lifetime: self.lower_lifetime(lifetime), | |
1473 | bounds: self.lower_param_bounds(bounds, ImplTraitContext::disallowed()), | |
1474 | }), | |
dfeec247 | 1475 | WherePredicate::EqPredicate(WhereEqPredicate { id, ref lhs_ty, ref rhs_ty, span }) => { |
416331ca XL |
1476 | hir::WherePredicate::EqPredicate(hir::WhereEqPredicate { |
1477 | hir_id: self.lower_node_id(id), | |
1478 | lhs_ty: self.lower_ty(lhs_ty, ImplTraitContext::disallowed()), | |
1479 | rhs_ty: self.lower_ty(rhs_ty, ImplTraitContext::disallowed()), | |
1480 | span, | |
1481 | }) | |
dfeec247 XL |
1482 | } |
1483 | } | |
1484 | } | |
1485 | } | |
1486 | ||
1487 | /// Helper struct for delayed construction of Generics. | |
1488 | pub(super) struct GenericsCtor<'hir> { | |
1489 | pub(super) params: SmallVec<[hir::GenericParam<'hir>; 4]>, | |
1490 | where_clause: hir::WhereClause<'hir>, | |
1491 | span: Span, | |
1492 | } | |
1493 | ||
1494 | impl<'hir> GenericsCtor<'hir> { | |
1495 | pub(super) fn into_generics(self, arena: &'hir Arena<'hir>) -> hir::Generics<'hir> { | |
1496 | hir::Generics { | |
1497 | params: arena.alloc_from_iter(self.params), | |
1498 | where_clause: self.where_clause, | |
1499 | span: self.span, | |
416331ca XL |
1500 | } |
1501 | } | |
1502 | } |