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Commit | Line | Data |
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f2b60f7d FG |
1 | use super::errors::{ |
2 | AsyncGeneratorsNotSupported, AsyncNonMoveClosureNotSupported, AwaitOnlyInAsyncFnAndBlocks, | |
3 | BaseExpressionDoubleDot, ClosureCannotBeStatic, FunctionalRecordUpdateDestructuringAssignemnt, | |
4 | GeneratorTooManyParameters, InclusiveRangeWithNoEnd, NotSupportedForLifetimeBinderAsyncClosure, | |
5 | RustcBoxAttributeError, UnderscoreExprLhsAssign, | |
6 | }; | |
923072b8 | 7 | use super::ResolverAstLoweringExt; |
dfeec247 | 8 | use super::{ImplTraitContext, LoweringContext, ParamMode, ParenthesizedGenericArgs}; |
923072b8 | 9 | use crate::{FnDeclKind, ImplTraitPosition}; |
74b04a01 XL |
10 | use rustc_ast::attr; |
11 | use rustc_ast::ptr::P as AstP; | |
3dfed10e | 12 | use rustc_ast::*; |
f9f354fc | 13 | use rustc_data_structures::stack::ensure_sufficient_stack; |
dfeec247 XL |
14 | use rustc_hir as hir; |
15 | use rustc_hir::def::Res; | |
6a06907d | 16 | use rustc_hir::definitions::DefPathData; |
3dfed10e | 17 | use rustc_span::source_map::{respan, DesugaringKind, Span, Spanned}; |
5099ac24 | 18 | use rustc_span::symbol::{sym, Ident}; |
3c0e092e | 19 | use rustc_span::DUMMY_SP; |
f2b60f7d | 20 | use thin_vec::thin_vec; |
416331ca | 21 | |
dfeec247 XL |
22 | impl<'hir> LoweringContext<'_, 'hir> { |
23 | fn lower_exprs(&mut self, exprs: &[AstP<Expr>]) -> &'hir [hir::Expr<'hir>] { | |
24 | self.arena.alloc_from_iter(exprs.iter().map(|x| self.lower_expr_mut(x))) | |
25 | } | |
60c5eb7d | 26 | |
dfeec247 XL |
27 | pub(super) fn lower_expr(&mut self, e: &Expr) -> &'hir hir::Expr<'hir> { |
28 | self.arena.alloc(self.lower_expr_mut(e)) | |
416331ca XL |
29 | } |
30 | ||
dfeec247 | 31 | pub(super) fn lower_expr_mut(&mut self, e: &Expr) -> hir::Expr<'hir> { |
f9f354fc XL |
32 | ensure_sufficient_stack(|| { |
33 | let kind = match e.kind { | |
34 | ExprKind::Box(ref inner) => hir::ExprKind::Box(self.lower_expr(inner)), | |
35 | ExprKind::Array(ref exprs) => hir::ExprKind::Array(self.lower_exprs(exprs)), | |
29967ef6 XL |
36 | ExprKind::ConstBlock(ref anon_const) => { |
37 | let anon_const = self.lower_anon_const(anon_const); | |
38 | hir::ExprKind::ConstBlock(anon_const) | |
39 | } | |
f9f354fc XL |
40 | ExprKind::Repeat(ref expr, ref count) => { |
41 | let expr = self.lower_expr(expr); | |
a2a8927a | 42 | let count = self.lower_array_length(count); |
f9f354fc XL |
43 | hir::ExprKind::Repeat(expr, count) |
44 | } | |
45 | ExprKind::Tup(ref elts) => hir::ExprKind::Tup(self.lower_exprs(elts)), | |
46 | ExprKind::Call(ref f, ref args) => { | |
923072b8 FG |
47 | if e.attrs.get(0).map_or(false, |a| a.has_name(sym::rustc_box)) { |
48 | if let [inner] = &args[..] && e.attrs.len() == 1 { | |
49 | let kind = hir::ExprKind::Box(self.lower_expr(&inner)); | |
50 | let hir_id = self.lower_node_id(e.id); | |
51 | return hir::Expr { hir_id, kind, span: self.lower_span(e.span) }; | |
52 | } else { | |
f2b60f7d | 53 | self.tcx.sess.emit_err(RustcBoxAttributeError { span: e.span }); |
923072b8 FG |
54 | hir::ExprKind::Err |
55 | } | |
56 | } else if let Some(legacy_args) = self.resolver.legacy_const_generic_args(f) { | |
6a06907d XL |
57 | self.lower_legacy_const_generics((**f).clone(), args.clone(), &legacy_args) |
58 | } else { | |
59 | let f = self.lower_expr(f); | |
60 | hir::ExprKind::Call(f, self.lower_exprs(args)) | |
61 | } | |
f9f354fc | 62 | } |
2b03887a | 63 | ExprKind::MethodCall(ref seg, ref receiver, ref args, span) => { |
f9f354fc XL |
64 | let hir_seg = self.arena.alloc(self.lower_path_segment( |
65 | e.span, | |
66 | seg, | |
67 | ParamMode::Optional, | |
f9f354fc | 68 | ParenthesizedGenericArgs::Err, |
f2b60f7d | 69 | &ImplTraitContext::Disallowed(ImplTraitPosition::Path), |
f9f354fc | 70 | )); |
2b03887a | 71 | let receiver = self.lower_expr(receiver); |
f2b60f7d | 72 | let args = |
2b03887a | 73 | self.arena.alloc_from_iter(args.iter().map(|x| self.lower_expr_mut(x))); |
f2b60f7d | 74 | hir::ExprKind::MethodCall(hir_seg, receiver, args, self.lower_span(span)) |
f9f354fc XL |
75 | } |
76 | ExprKind::Binary(binop, ref lhs, ref rhs) => { | |
77 | let binop = self.lower_binop(binop); | |
78 | let lhs = self.lower_expr(lhs); | |
79 | let rhs = self.lower_expr(rhs); | |
80 | hir::ExprKind::Binary(binop, lhs, rhs) | |
81 | } | |
82 | ExprKind::Unary(op, ref ohs) => { | |
83 | let op = self.lower_unop(op); | |
84 | let ohs = self.lower_expr(ohs); | |
85 | hir::ExprKind::Unary(op, ohs) | |
86 | } | |
94222f64 XL |
87 | ExprKind::Lit(ref l) => { |
88 | hir::ExprKind::Lit(respan(self.lower_span(l.span), l.kind.clone())) | |
89 | } | |
f9f354fc XL |
90 | ExprKind::Cast(ref expr, ref ty) => { |
91 | let expr = self.lower_expr(expr); | |
5099ac24 | 92 | let ty = |
f2b60f7d | 93 | self.lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::Type)); |
f9f354fc XL |
94 | hir::ExprKind::Cast(expr, ty) |
95 | } | |
96 | ExprKind::Type(ref expr, ref ty) => { | |
97 | let expr = self.lower_expr(expr); | |
5099ac24 | 98 | let ty = |
f2b60f7d | 99 | self.lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::Type)); |
f9f354fc XL |
100 | hir::ExprKind::Type(expr, ty) |
101 | } | |
102 | ExprKind::AddrOf(k, m, ref ohs) => { | |
103 | let ohs = self.lower_expr(ohs); | |
104 | hir::ExprKind::AddrOf(k, m, ohs) | |
105 | } | |
a2a8927a XL |
106 | ExprKind::Let(ref pat, ref scrutinee, span) => { |
107 | hir::ExprKind::Let(self.arena.alloc(hir::Let { | |
108 | hir_id: self.next_id(), | |
109 | span: self.lower_span(span), | |
110 | pat: self.lower_pat(pat), | |
111 | ty: None, | |
112 | init: self.lower_expr(scrutinee), | |
113 | })) | |
114 | } | |
94222f64 XL |
115 | ExprKind::If(ref cond, ref then, ref else_opt) => { |
116 | self.lower_expr_if(cond, then, else_opt.as_deref()) | |
f9f354fc | 117 | } |
c295e0f8 XL |
118 | ExprKind::While(ref cond, ref body, opt_label) => { |
119 | self.with_loop_scope(e.id, |this| { | |
120 | let span = | |
121 | this.mark_span_with_reason(DesugaringKind::WhileLoop, e.span, None); | |
122 | this.lower_expr_while_in_loop_scope(span, cond, body, opt_label) | |
123 | }) | |
124 | } | |
f9f354fc XL |
125 | ExprKind::Loop(ref body, opt_label) => self.with_loop_scope(e.id, |this| { |
126 | hir::ExprKind::Loop( | |
127 | this.lower_block(body, false), | |
94222f64 | 128 | this.lower_label(opt_label), |
f9f354fc | 129 | hir::LoopSource::Loop, |
5869c6ff | 130 | DUMMY_SP, |
dfeec247 | 131 | ) |
f9f354fc XL |
132 | }), |
133 | ExprKind::TryBlock(ref body) => self.lower_expr_try_block(body), | |
134 | ExprKind::Match(ref expr, ref arms) => hir::ExprKind::Match( | |
135 | self.lower_expr(expr), | |
136 | self.arena.alloc_from_iter(arms.iter().map(|x| self.lower_arm(x))), | |
137 | hir::MatchSource::Normal, | |
138 | ), | |
139 | ExprKind::Async(capture_clause, closure_node_id, ref block) => self | |
140 | .make_async_expr( | |
141 | capture_clause, | |
142 | closure_node_id, | |
143 | None, | |
144 | block.span, | |
145 | hir::AsyncGeneratorKind::Block, | |
146 | |this| this.with_new_scopes(|this| this.lower_block_expr(block)), | |
147 | ), | |
a2a8927a | 148 | ExprKind::Await(ref expr) => { |
f2b60f7d FG |
149 | let dot_await_span = if expr.span.hi() < e.span.hi() { |
150 | let span_with_whitespace = self | |
151 | .tcx | |
152 | .sess | |
153 | .source_map() | |
154 | .span_extend_while(expr.span, char::is_whitespace) | |
155 | .unwrap_or(expr.span); | |
156 | span_with_whitespace.shrink_to_hi().with_hi(e.span.hi()) | |
a2a8927a XL |
157 | } else { |
158 | // this is a recovered `await expr` | |
159 | e.span | |
160 | }; | |
f2b60f7d | 161 | self.lower_expr_await(dot_await_span, expr) |
a2a8927a | 162 | } |
f9f354fc | 163 | ExprKind::Closure( |
064997fb | 164 | ref binder, |
f9f354fc XL |
165 | capture_clause, |
166 | asyncness, | |
167 | movability, | |
168 | ref decl, | |
169 | ref body, | |
170 | fn_decl_span, | |
171 | ) => { | |
172 | if let Async::Yes { closure_id, .. } = asyncness { | |
173 | self.lower_expr_async_closure( | |
064997fb | 174 | binder, |
f9f354fc | 175 | capture_clause, |
923072b8 | 176 | e.id, |
f9f354fc XL |
177 | closure_id, |
178 | decl, | |
179 | body, | |
180 | fn_decl_span, | |
181 | ) | |
182 | } else { | |
183 | self.lower_expr_closure( | |
064997fb | 184 | binder, |
f9f354fc | 185 | capture_clause, |
923072b8 | 186 | e.id, |
f9f354fc XL |
187 | movability, |
188 | decl, | |
189 | body, | |
190 | fn_decl_span, | |
191 | ) | |
192 | } | |
dfeec247 | 193 | } |
f9f354fc | 194 | ExprKind::Block(ref blk, opt_label) => { |
94222f64 | 195 | let opt_label = self.lower_label(opt_label); |
f9f354fc XL |
196 | hir::ExprKind::Block(self.lower_block(blk, opt_label.is_some()), opt_label) |
197 | } | |
198 | ExprKind::Assign(ref el, ref er, span) => { | |
29967ef6 | 199 | self.lower_expr_assign(el, er, span, e.span) |
f9f354fc XL |
200 | } |
201 | ExprKind::AssignOp(op, ref el, ref er) => hir::ExprKind::AssignOp( | |
202 | self.lower_binop(op), | |
203 | self.lower_expr(el), | |
204 | self.lower_expr(er), | |
205 | ), | |
94222f64 XL |
206 | ExprKind::Field(ref el, ident) => { |
207 | hir::ExprKind::Field(self.lower_expr(el), self.lower_ident(ident)) | |
208 | } | |
f9f354fc XL |
209 | ExprKind::Index(ref el, ref er) => { |
210 | hir::ExprKind::Index(self.lower_expr(el), self.lower_expr(er)) | |
211 | } | |
212 | ExprKind::Range(Some(ref e1), Some(ref e2), RangeLimits::Closed) => { | |
213 | self.lower_expr_range_closed(e.span, e1, e2) | |
214 | } | |
215 | ExprKind::Range(ref e1, ref e2, lims) => { | |
216 | self.lower_expr_range(e.span, e1.as_deref(), e2.as_deref(), lims) | |
217 | } | |
fc512014 | 218 | ExprKind::Underscore => { |
f2b60f7d | 219 | self.tcx.sess.emit_err(UnderscoreExprLhsAssign { span: e.span }); |
fc512014 XL |
220 | hir::ExprKind::Err |
221 | } | |
f9f354fc XL |
222 | ExprKind::Path(ref qself, ref path) => { |
223 | let qpath = self.lower_qpath( | |
dfeec247 | 224 | e.id, |
f9f354fc | 225 | qself, |
dfeec247 XL |
226 | path, |
227 | ParamMode::Optional, | |
f2b60f7d | 228 | &ImplTraitContext::Disallowed(ImplTraitPosition::Path), |
f9f354fc XL |
229 | ); |
230 | hir::ExprKind::Path(qpath) | |
231 | } | |
232 | ExprKind::Break(opt_label, ref opt_expr) => { | |
233 | let opt_expr = opt_expr.as_ref().map(|x| self.lower_expr(x)); | |
234 | hir::ExprKind::Break(self.lower_jump_destination(e.id, opt_label), opt_expr) | |
235 | } | |
236 | ExprKind::Continue(opt_label) => { | |
237 | hir::ExprKind::Continue(self.lower_jump_destination(e.id, opt_label)) | |
238 | } | |
239 | ExprKind::Ret(ref e) => { | |
240 | let e = e.as_ref().map(|x| self.lower_expr(x)); | |
241 | hir::ExprKind::Ret(e) | |
242 | } | |
04454e1e | 243 | ExprKind::Yeet(ref sub_expr) => self.lower_expr_yeet(e.span, sub_expr.as_deref()), |
17df50a5 XL |
244 | ExprKind::InlineAsm(ref asm) => { |
245 | hir::ExprKind::InlineAsm(self.lower_inline_asm(e.span, asm)) | |
246 | } | |
6a06907d XL |
247 | ExprKind::Struct(ref se) => { |
248 | let rest = match &se.rest { | |
29967ef6 XL |
249 | StructRest::Base(e) => Some(self.lower_expr(e)), |
250 | StructRest::Rest(sp) => { | |
f2b60f7d | 251 | self.tcx.sess.emit_err(BaseExpressionDoubleDot { span: *sp }); |
29967ef6 XL |
252 | Some(&*self.arena.alloc(self.expr_err(*sp))) |
253 | } | |
254 | StructRest::None => None, | |
255 | }; | |
f9f354fc XL |
256 | hir::ExprKind::Struct( |
257 | self.arena.alloc(self.lower_qpath( | |
258 | e.id, | |
17df50a5 | 259 | &se.qself, |
6a06907d | 260 | &se.path, |
f9f354fc | 261 | ParamMode::Optional, |
f2b60f7d | 262 | &ImplTraitContext::Disallowed(ImplTraitPosition::Path), |
f9f354fc | 263 | )), |
6a06907d XL |
264 | self.arena |
265 | .alloc_from_iter(se.fields.iter().map(|x| self.lower_expr_field(x))), | |
29967ef6 | 266 | rest, |
f9f354fc XL |
267 | ) |
268 | } | |
269 | ExprKind::Yield(ref opt_expr) => self.lower_expr_yield(e.span, opt_expr.as_deref()), | |
270 | ExprKind::Err => hir::ExprKind::Err, | |
271 | ExprKind::Try(ref sub_expr) => self.lower_expr_try(e.span, sub_expr), | |
272 | ExprKind::Paren(ref ex) => { | |
273 | let mut ex = self.lower_expr_mut(ex); | |
274 | // Include parens in span, but only if it is a super-span. | |
275 | if e.span.contains(ex.span) { | |
94222f64 | 276 | ex.span = self.lower_span(e.span); |
f9f354fc XL |
277 | } |
278 | // Merge attributes into the inner expression. | |
6a06907d | 279 | if !e.attrs.is_empty() { |
3c0e092e XL |
280 | let old_attrs = |
281 | self.attrs.get(&ex.hir_id.local_id).map(|la| *la).unwrap_or(&[]); | |
6a06907d | 282 | self.attrs.insert( |
3c0e092e | 283 | ex.hir_id.local_id, |
6a06907d XL |
284 | &*self.arena.alloc_from_iter( |
285 | e.attrs | |
286 | .iter() | |
287 | .map(|a| self.lower_attr(a)) | |
288 | .chain(old_attrs.iter().cloned()), | |
289 | ), | |
290 | ); | |
291 | } | |
f9f354fc | 292 | return ex; |
416331ca | 293 | } |
416331ca | 294 | |
f9f354fc XL |
295 | // Desugar `ExprForLoop` |
296 | // from: `[opt_ident]: for <pat> in <head> <body>` | |
297 | ExprKind::ForLoop(ref pat, ref head, ref body, opt_label) => { | |
298 | return self.lower_expr_for(e, pat, head, body, opt_label); | |
299 | } | |
300 | ExprKind::MacCall(_) => panic!("{:?} shouldn't exist here", e.span), | |
301 | }; | |
416331ca | 302 | |
6a06907d XL |
303 | let hir_id = self.lower_node_id(e.id); |
304 | self.lower_attrs(hir_id, &e.attrs); | |
94222f64 | 305 | hir::Expr { hir_id, kind, span: self.lower_span(e.span) } |
f9f354fc | 306 | }) |
416331ca XL |
307 | } |
308 | ||
309 | fn lower_unop(&mut self, u: UnOp) -> hir::UnOp { | |
310 | match u { | |
6a06907d XL |
311 | UnOp::Deref => hir::UnOp::Deref, |
312 | UnOp::Not => hir::UnOp::Not, | |
313 | UnOp::Neg => hir::UnOp::Neg, | |
416331ca XL |
314 | } |
315 | } | |
316 | ||
317 | fn lower_binop(&mut self, b: BinOp) -> hir::BinOp { | |
318 | Spanned { | |
319 | node: match b.node { | |
320 | BinOpKind::Add => hir::BinOpKind::Add, | |
321 | BinOpKind::Sub => hir::BinOpKind::Sub, | |
322 | BinOpKind::Mul => hir::BinOpKind::Mul, | |
323 | BinOpKind::Div => hir::BinOpKind::Div, | |
324 | BinOpKind::Rem => hir::BinOpKind::Rem, | |
325 | BinOpKind::And => hir::BinOpKind::And, | |
326 | BinOpKind::Or => hir::BinOpKind::Or, | |
327 | BinOpKind::BitXor => hir::BinOpKind::BitXor, | |
328 | BinOpKind::BitAnd => hir::BinOpKind::BitAnd, | |
329 | BinOpKind::BitOr => hir::BinOpKind::BitOr, | |
330 | BinOpKind::Shl => hir::BinOpKind::Shl, | |
331 | BinOpKind::Shr => hir::BinOpKind::Shr, | |
332 | BinOpKind::Eq => hir::BinOpKind::Eq, | |
333 | BinOpKind::Lt => hir::BinOpKind::Lt, | |
334 | BinOpKind::Le => hir::BinOpKind::Le, | |
335 | BinOpKind::Ne => hir::BinOpKind::Ne, | |
336 | BinOpKind::Ge => hir::BinOpKind::Ge, | |
337 | BinOpKind::Gt => hir::BinOpKind::Gt, | |
338 | }, | |
94222f64 | 339 | span: self.lower_span(b.span), |
416331ca XL |
340 | } |
341 | } | |
342 | ||
6a06907d XL |
343 | fn lower_legacy_const_generics( |
344 | &mut self, | |
345 | mut f: Expr, | |
346 | args: Vec<AstP<Expr>>, | |
347 | legacy_args_idx: &[usize], | |
348 | ) -> hir::ExprKind<'hir> { | |
5e7ed085 FG |
349 | let ExprKind::Path(None, ref mut path) = f.kind else { |
350 | unreachable!(); | |
6a06907d XL |
351 | }; |
352 | ||
353 | // Split the arguments into const generics and normal arguments | |
354 | let mut real_args = vec![]; | |
355 | let mut generic_args = vec![]; | |
356 | for (idx, arg) in args.into_iter().enumerate() { | |
357 | if legacy_args_idx.contains(&idx) { | |
c295e0f8 | 358 | let parent_def_id = self.current_hir_id_owner; |
923072b8 | 359 | let node_id = self.next_node_id(); |
6a06907d XL |
360 | |
361 | // Add a definition for the in-band const def. | |
2b03887a | 362 | self.create_def(parent_def_id.def_id, node_id, DefPathData::AnonConst); |
6a06907d XL |
363 | |
364 | let anon_const = AnonConst { id: node_id, value: arg }; | |
365 | generic_args.push(AngleBracketedArg::Arg(GenericArg::Const(anon_const))); | |
366 | } else { | |
367 | real_args.push(arg); | |
368 | } | |
369 | } | |
370 | ||
371 | // Add generic args to the last element of the path. | |
372 | let last_segment = path.segments.last_mut().unwrap(); | |
373 | assert!(last_segment.args.is_none()); | |
374 | last_segment.args = Some(AstP(GenericArgs::AngleBracketed(AngleBracketedArgs { | |
375 | span: DUMMY_SP, | |
376 | args: generic_args, | |
377 | }))); | |
378 | ||
379 | // Now lower everything as normal. | |
380 | let f = self.lower_expr(&f); | |
381 | hir::ExprKind::Call(f, self.lower_exprs(&real_args)) | |
382 | } | |
383 | ||
416331ca XL |
384 | fn lower_expr_if( |
385 | &mut self, | |
416331ca XL |
386 | cond: &Expr, |
387 | then: &Block, | |
388 | else_opt: Option<&Expr>, | |
5869c6ff | 389 | ) -> hir::ExprKind<'hir> { |
2b03887a | 390 | let lowered_cond = self.lower_cond(cond); |
94222f64 | 391 | let then_expr = self.lower_block_expr(then); |
5869c6ff | 392 | if let Some(rslt) = else_opt { |
2b03887a FG |
393 | hir::ExprKind::If( |
394 | lowered_cond, | |
395 | self.arena.alloc(then_expr), | |
396 | Some(self.lower_expr(rslt)), | |
397 | ) | |
5869c6ff | 398 | } else { |
2b03887a | 399 | hir::ExprKind::If(lowered_cond, self.arena.alloc(then_expr), None) |
5869c6ff XL |
400 | } |
401 | } | |
402 | ||
2b03887a FG |
403 | // Lowers a condition (i.e. `cond` in `if cond` or `while cond`), wrapping it in a terminating scope |
404 | // so that temporaries created in the condition don't live beyond it. | |
405 | fn lower_cond(&mut self, cond: &Expr) -> &'hir hir::Expr<'hir> { | |
406 | fn has_let_expr(expr: &Expr) -> bool { | |
407 | match &expr.kind { | |
408 | ExprKind::Binary(_, lhs, rhs) => has_let_expr(lhs) || has_let_expr(rhs), | |
409 | ExprKind::Let(..) => true, | |
5099ac24 | 410 | _ => false, |
94222f64 XL |
411 | } |
412 | } | |
2b03887a FG |
413 | |
414 | // We have to take special care for `let` exprs in the condition, e.g. in | |
415 | // `if let pat = val` or `if foo && let pat = val`, as we _do_ want `val` to live beyond the | |
416 | // condition in this case. | |
417 | // | |
418 | // In order to mantain the drop behavior for the non `let` parts of the condition, | |
419 | // we still wrap them in terminating scopes, e.g. `if foo && let pat = val` essentially | |
420 | // gets transformed into `if { let _t = foo; _t } && let pat = val` | |
421 | match &cond.kind { | |
422 | ExprKind::Binary(op @ Spanned { node: ast::BinOpKind::And, .. }, lhs, rhs) | |
423 | if has_let_expr(cond) => | |
424 | { | |
425 | let op = self.lower_binop(*op); | |
426 | let lhs = self.lower_cond(lhs); | |
427 | let rhs = self.lower_cond(rhs); | |
428 | ||
429 | self.arena.alloc(self.expr( | |
430 | cond.span, | |
431 | hir::ExprKind::Binary(op, lhs, rhs), | |
432 | AttrVec::new(), | |
433 | )) | |
434 | } | |
435 | ExprKind::Let(..) => self.lower_expr(cond), | |
436 | _ => { | |
437 | let cond = self.lower_expr(cond); | |
438 | let reason = DesugaringKind::CondTemporary; | |
439 | let span_block = self.mark_span_with_reason(reason, cond.span, None); | |
440 | self.expr_drop_temps(span_block, cond, AttrVec::new()) | |
441 | } | |
5099ac24 | 442 | } |
416331ca XL |
443 | } |
444 | ||
94222f64 XL |
445 | // We desugar: `'label: while $cond $body` into: |
446 | // | |
447 | // ``` | |
448 | // 'label: loop { | |
449 | // if { let _t = $cond; _t } { | |
450 | // $body | |
451 | // } | |
452 | // else { | |
453 | // break; | |
454 | // } | |
455 | // } | |
456 | // ``` | |
457 | // | |
458 | // Wrap in a construct equivalent to `{ let _t = $cond; _t }` | |
459 | // to preserve drop semantics since `while $cond { ... }` does not | |
460 | // let temporaries live outside of `cond`. | |
416331ca XL |
461 | fn lower_expr_while_in_loop_scope( |
462 | &mut self, | |
463 | span: Span, | |
464 | cond: &Expr, | |
465 | body: &Block, | |
dfeec247 XL |
466 | opt_label: Option<Label>, |
467 | ) -> hir::ExprKind<'hir> { | |
2b03887a | 468 | let lowered_cond = self.with_loop_condition_scope(|t| t.lower_cond(cond)); |
94222f64 | 469 | let then = self.lower_block_expr(body); |
f2b60f7d | 470 | let expr_break = self.expr_break(span, AttrVec::new()); |
94222f64 XL |
471 | let stmt_break = self.stmt_expr(span, expr_break); |
472 | let else_blk = self.block_all(span, arena_vec![self; stmt_break], None); | |
f2b60f7d | 473 | let else_expr = self.arena.alloc(self.expr_block(else_blk, AttrVec::new())); |
2b03887a | 474 | let if_kind = hir::ExprKind::If(lowered_cond, self.arena.alloc(then), Some(else_expr)); |
f2b60f7d | 475 | let if_expr = self.expr(span, if_kind, AttrVec::new()); |
94222f64 | 476 | let block = self.block_expr(self.arena.alloc(if_expr)); |
c295e0f8 XL |
477 | let span = self.lower_span(span.with_hi(cond.span.hi())); |
478 | let opt_label = self.lower_label(opt_label); | |
479 | hir::ExprKind::Loop(block, opt_label, hir::LoopSource::While, span) | |
416331ca XL |
480 | } |
481 | ||
17df50a5 XL |
482 | /// Desugar `try { <stmts>; <expr> }` into `{ <stmts>; ::std::ops::Try::from_output(<expr>) }`, |
483 | /// `try { <stmts>; }` into `{ <stmts>; ::std::ops::Try::from_output(()) }` | |
e74abb32 | 484 | /// and save the block id to use it as a break target for desugaring of the `?` operator. |
dfeec247 | 485 | fn lower_expr_try_block(&mut self, body: &Block) -> hir::ExprKind<'hir> { |
416331ca | 486 | self.with_catch_scope(body.id, |this| { |
dfeec247 | 487 | let mut block = this.lower_block_noalloc(body, true); |
e74abb32 | 488 | |
e74abb32 | 489 | // Final expression of the block (if present) or `()` with span at the end of block |
29967ef6 XL |
490 | let (try_span, tail_expr) = if let Some(expr) = block.expr.take() { |
491 | ( | |
492 | this.mark_span_with_reason( | |
493 | DesugaringKind::TryBlock, | |
494 | expr.span, | |
495 | this.allow_try_trait.clone(), | |
496 | ), | |
497 | expr, | |
498 | ) | |
499 | } else { | |
500 | let try_span = this.mark_span_with_reason( | |
501 | DesugaringKind::TryBlock, | |
064997fb | 502 | this.tcx.sess.source_map().end_point(body.span), |
29967ef6 XL |
503 | this.allow_try_trait.clone(), |
504 | ); | |
505 | ||
506 | (try_span, this.expr_unit(try_span)) | |
507 | }; | |
e74abb32 | 508 | |
dfeec247 XL |
509 | let ok_wrapped_span = |
510 | this.mark_span_with_reason(DesugaringKind::TryBlock, tail_expr.span, None); | |
e74abb32 | 511 | |
17df50a5 | 512 | // `::std::ops::Try::from_output($tail_expr)` |
e74abb32 | 513 | block.expr = Some(this.wrap_in_try_constructor( |
17df50a5 | 514 | hir::LangItem::TryTraitFromOutput, |
dfeec247 XL |
515 | try_span, |
516 | tail_expr, | |
517 | ok_wrapped_span, | |
518 | )); | |
e74abb32 | 519 | |
dfeec247 | 520 | hir::ExprKind::Block(this.arena.alloc(block), None) |
416331ca XL |
521 | }) |
522 | } | |
523 | ||
524 | fn wrap_in_try_constructor( | |
525 | &mut self, | |
3dfed10e | 526 | lang_item: hir::LangItem, |
e74abb32 | 527 | method_span: Span, |
dfeec247 | 528 | expr: &'hir hir::Expr<'hir>, |
e74abb32 | 529 | overall_span: Span, |
dfeec247 | 530 | ) -> &'hir hir::Expr<'hir> { |
a2a8927a XL |
531 | let constructor = self.arena.alloc(self.expr_lang_item_path( |
532 | method_span, | |
533 | lang_item, | |
f2b60f7d | 534 | AttrVec::new(), |
a2a8927a XL |
535 | None, |
536 | )); | |
dfeec247 | 537 | self.expr_call(overall_span, constructor, std::slice::from_ref(expr)) |
416331ca XL |
538 | } |
539 | ||
dfeec247 | 540 | fn lower_arm(&mut self, arm: &Arm) -> hir::Arm<'hir> { |
fc512014 XL |
541 | let pat = self.lower_pat(&arm.pat); |
542 | let guard = arm.guard.as_ref().map(|cond| { | |
923072b8 FG |
543 | if let ExprKind::Let(ref pat, ref scrutinee, span) = cond.kind { |
544 | hir::Guard::IfLet(self.arena.alloc(hir::Let { | |
545 | hir_id: self.next_id(), | |
546 | span: self.lower_span(span), | |
547 | pat: self.lower_pat(pat), | |
548 | ty: None, | |
549 | init: self.lower_expr(scrutinee), | |
550 | })) | |
fc512014 XL |
551 | } else { |
552 | hir::Guard::If(self.lower_expr(cond)) | |
553 | } | |
554 | }); | |
6a06907d XL |
555 | let hir_id = self.next_id(); |
556 | self.lower_attrs(hir_id, &arm.attrs); | |
94222f64 XL |
557 | hir::Arm { |
558 | hir_id, | |
559 | pat, | |
560 | guard, | |
561 | body: self.lower_expr(&arm.body), | |
562 | span: self.lower_span(arm.span), | |
563 | } | |
416331ca XL |
564 | } |
565 | ||
ba9703b0 XL |
566 | /// Lower an `async` construct to a generator that is then wrapped so it implements `Future`. |
567 | /// | |
568 | /// This results in: | |
569 | /// | |
570 | /// ```text | |
571 | /// std::future::from_generator(static move? |_task_context| -> <ret_ty> { | |
572 | /// <body> | |
573 | /// }) | |
574 | /// ``` | |
416331ca XL |
575 | pub(super) fn make_async_expr( |
576 | &mut self, | |
577 | capture_clause: CaptureBy, | |
578 | closure_node_id: NodeId, | |
579 | ret_ty: Option<AstP<Ty>>, | |
580 | span: Span, | |
e74abb32 | 581 | async_gen_kind: hir::AsyncGeneratorKind, |
dfeec247 XL |
582 | body: impl FnOnce(&mut Self) -> hir::Expr<'hir>, |
583 | ) -> hir::ExprKind<'hir> { | |
416331ca | 584 | let output = match ret_ty { |
5099ac24 | 585 | Some(ty) => hir::FnRetTy::Return( |
f2b60f7d | 586 | self.lower_ty(&ty, &ImplTraitContext::Disallowed(ImplTraitPosition::AsyncBlock)), |
5099ac24 | 587 | ), |
94222f64 | 588 | None => hir::FnRetTy::DefaultReturn(self.lower_span(span)), |
416331ca | 589 | }; |
ba9703b0 XL |
590 | |
591 | // Resume argument type. We let the compiler infer this to simplify the lowering. It is | |
592 | // fully constrained by `future::from_generator`. | |
94222f64 XL |
593 | let input_ty = hir::Ty { |
594 | hir_id: self.next_id(), | |
595 | kind: hir::TyKind::Infer, | |
596 | span: self.lower_span(span), | |
597 | }; | |
ba9703b0 XL |
598 | |
599 | // The closure/generator `FnDecl` takes a single (resume) argument of type `input_ty`. | |
923072b8 | 600 | let fn_decl = self.arena.alloc(hir::FnDecl { |
ba9703b0 XL |
601 | inputs: arena_vec![self; input_ty], |
602 | output, | |
603 | c_variadic: false, | |
604 | implicit_self: hir::ImplicitSelfKind::None, | |
605 | }); | |
606 | ||
607 | // Lower the argument pattern/ident. The ident is used again in the `.await` lowering. | |
608 | let (pat, task_context_hid) = self.pat_ident_binding_mode( | |
609 | span, | |
610 | Ident::with_dummy_span(sym::_task_context), | |
f2b60f7d | 611 | hir::BindingAnnotation::MUT, |
ba9703b0 | 612 | ); |
94222f64 XL |
613 | let param = hir::Param { |
614 | hir_id: self.next_id(), | |
615 | pat, | |
616 | ty_span: self.lower_span(span), | |
617 | span: self.lower_span(span), | |
618 | }; | |
ba9703b0 XL |
619 | let params = arena_vec![self; param]; |
620 | ||
923072b8 | 621 | let body = self.lower_body(move |this| { |
e74abb32 | 622 | this.generator_kind = Some(hir::GeneratorKind::Async(async_gen_kind)); |
ba9703b0 XL |
623 | |
624 | let old_ctx = this.task_context; | |
625 | this.task_context = Some(task_context_hid); | |
626 | let res = body(this); | |
627 | this.task_context = old_ctx; | |
628 | (params, res) | |
416331ca XL |
629 | }); |
630 | ||
ba9703b0 | 631 | // `static |_task_context| -> <ret_ty> { body }`: |
064997fb FG |
632 | let generator_kind = { |
633 | let c = self.arena.alloc(hir::Closure { | |
634 | binder: hir::ClosureBinder::Default, | |
635 | capture_clause, | |
636 | bound_generic_params: &[], | |
637 | fn_decl, | |
638 | body, | |
639 | fn_decl_span: self.lower_span(span), | |
640 | movability: Some(hir::Movability::Static), | |
641 | }); | |
642 | ||
643 | hir::ExprKind::Closure(c) | |
923072b8 | 644 | }; |
94222f64 XL |
645 | let generator = hir::Expr { |
646 | hir_id: self.lower_node_id(closure_node_id), | |
647 | kind: generator_kind, | |
648 | span: self.lower_span(span), | |
649 | }; | |
416331ca XL |
650 | |
651 | // `future::from_generator`: | |
dfeec247 XL |
652 | let unstable_span = |
653 | self.mark_span_with_reason(DesugaringKind::Async, span, self.allow_gen_future.clone()); | |
a2a8927a XL |
654 | let gen_future = self.expr_lang_item_path( |
655 | unstable_span, | |
656 | hir::LangItem::FromGenerator, | |
f2b60f7d | 657 | AttrVec::new(), |
a2a8927a XL |
658 | None, |
659 | ); | |
416331ca XL |
660 | |
661 | // `future::from_generator(generator)`: | |
dfeec247 | 662 | hir::ExprKind::Call(self.arena.alloc(gen_future), arena_vec![self; generator]) |
416331ca XL |
663 | } |
664 | ||
665 | /// Desugar `<expr>.await` into: | |
04454e1e | 666 | /// ```ignore (pseudo-rust) |
a2a8927a | 667 | /// match ::std::future::IntoFuture::into_future(<expr>) { |
5e7ed085 | 668 | /// mut __awaitee => loop { |
ba9703b0 | 669 | /// match unsafe { ::std::future::Future::poll( |
5e7ed085 | 670 | /// <::std::pin::Pin>::new_unchecked(&mut __awaitee), |
ba9703b0 XL |
671 | /// ::std::future::get_context(task_context), |
672 | /// ) } { | |
416331ca | 673 | /// ::std::task::Poll::Ready(result) => break result, |
e1599b0c | 674 | /// ::std::task::Poll::Pending => {} |
416331ca | 675 | /// } |
ba9703b0 | 676 | /// task_context = yield (); |
416331ca XL |
677 | /// } |
678 | /// } | |
679 | /// ``` | |
5099ac24 FG |
680 | fn lower_expr_await(&mut self, dot_await_span: Span, expr: &Expr) -> hir::ExprKind<'hir> { |
681 | let full_span = expr.span.to(dot_await_span); | |
416331ca | 682 | match self.generator_kind { |
dfeec247 XL |
683 | Some(hir::GeneratorKind::Async(_)) => {} |
684 | Some(hir::GeneratorKind::Gen) | None => { | |
f2b60f7d | 685 | self.tcx.sess.emit_err(AwaitOnlyInAsyncFnAndBlocks { |
5099ac24 | 686 | dot_await_span, |
f2b60f7d FG |
687 | item_span: self.current_item, |
688 | }); | |
416331ca XL |
689 | } |
690 | } | |
a2a8927a | 691 | let span = self.mark_span_with_reason(DesugaringKind::Await, dot_await_span, None); |
416331ca XL |
692 | let gen_future_span = self.mark_span_with_reason( |
693 | DesugaringKind::Await, | |
5099ac24 | 694 | full_span, |
416331ca XL |
695 | self.allow_gen_future.clone(), |
696 | ); | |
a2a8927a XL |
697 | let expr = self.lower_expr_mut(expr); |
698 | let expr_hir_id = expr.hir_id; | |
416331ca | 699 | |
5e7ed085 FG |
700 | // Note that the name of this binding must not be changed to something else because |
701 | // debuggers and debugger extensions expect it to be called `__awaitee`. They use | |
702 | // this name to identify what is being awaited by a suspended async functions. | |
703 | let awaitee_ident = Ident::with_dummy_span(sym::__awaitee); | |
704 | let (awaitee_pat, awaitee_pat_hid) = | |
f2b60f7d | 705 | self.pat_ident_binding_mode(span, awaitee_ident, hir::BindingAnnotation::MUT); |
416331ca | 706 | |
ba9703b0 XL |
707 | let task_context_ident = Ident::with_dummy_span(sym::_task_context); |
708 | ||
709 | // unsafe { | |
710 | // ::std::future::Future::poll( | |
5e7ed085 | 711 | // ::std::pin::Pin::new_unchecked(&mut __awaitee), |
ba9703b0 XL |
712 | // ::std::future::get_context(task_context), |
713 | // ) | |
714 | // } | |
416331ca | 715 | let poll_expr = { |
5e7ed085 FG |
716 | let awaitee = self.expr_ident(span, awaitee_ident, awaitee_pat_hid); |
717 | let ref_mut_awaitee = self.expr_mut_addr_of(span, awaitee); | |
ba9703b0 XL |
718 | let task_context = if let Some(task_context_hid) = self.task_context { |
719 | self.expr_ident_mut(span, task_context_ident, task_context_hid) | |
720 | } else { | |
721 | // Use of `await` outside of an async context, we cannot use `task_context` here. | |
722 | self.expr_err(span) | |
723 | }; | |
3dfed10e | 724 | let new_unchecked = self.expr_call_lang_item_fn_mut( |
416331ca | 725 | span, |
3dfed10e | 726 | hir::LangItem::PinNewUnchecked, |
5e7ed085 | 727 | arena_vec![self; ref_mut_awaitee], |
a2a8927a | 728 | Some(expr_hir_id), |
416331ca | 729 | ); |
3dfed10e | 730 | let get_context = self.expr_call_lang_item_fn_mut( |
416331ca | 731 | gen_future_span, |
3dfed10e | 732 | hir::LangItem::GetContext, |
ba9703b0 | 733 | arena_vec![self; task_context], |
a2a8927a | 734 | Some(expr_hir_id), |
ba9703b0 | 735 | ); |
3dfed10e | 736 | let call = self.expr_call_lang_item_fn( |
ba9703b0 | 737 | span, |
3dfed10e | 738 | hir::LangItem::FuturePoll, |
ba9703b0 | 739 | arena_vec![self; new_unchecked, get_context], |
a2a8927a | 740 | Some(expr_hir_id), |
ba9703b0 XL |
741 | ); |
742 | self.arena.alloc(self.expr_unsafe(call)) | |
416331ca XL |
743 | }; |
744 | ||
745 | // `::std::task::Poll::Ready(result) => break result` | |
923072b8 | 746 | let loop_node_id = self.next_node_id(); |
416331ca XL |
747 | let loop_hir_id = self.lower_node_id(loop_node_id); |
748 | let ready_arm = { | |
e1599b0c | 749 | let x_ident = Ident::with_dummy_span(sym::result); |
5099ac24 FG |
750 | let (x_pat, x_pat_hid) = self.pat_ident(gen_future_span, x_ident); |
751 | let x_expr = self.expr_ident(gen_future_span, x_ident, x_pat_hid); | |
752 | let ready_field = self.single_pat_field(gen_future_span, x_pat); | |
a2a8927a XL |
753 | let ready_pat = self.pat_lang_item_variant( |
754 | span, | |
755 | hir::LangItem::PollReady, | |
756 | ready_field, | |
757 | Some(expr_hir_id), | |
758 | ); | |
dfeec247 XL |
759 | let break_x = self.with_loop_scope(loop_node_id, move |this| { |
760 | let expr_break = | |
761 | hir::ExprKind::Break(this.lower_loop_destination(None), Some(x_expr)); | |
f2b60f7d | 762 | this.arena.alloc(this.expr(gen_future_span, expr_break, AttrVec::new())) |
416331ca | 763 | }); |
e74abb32 | 764 | self.arm(ready_pat, break_x) |
416331ca XL |
765 | }; |
766 | ||
767 | // `::std::task::Poll::Pending => {}` | |
768 | let pending_arm = { | |
a2a8927a XL |
769 | let pending_pat = self.pat_lang_item_variant( |
770 | span, | |
771 | hir::LangItem::PollPending, | |
772 | &[], | |
773 | Some(expr_hir_id), | |
774 | ); | |
dfeec247 | 775 | let empty_block = self.expr_block_empty(span); |
e74abb32 | 776 | self.arm(pending_pat, empty_block) |
416331ca XL |
777 | }; |
778 | ||
e1599b0c | 779 | let inner_match_stmt = { |
416331ca XL |
780 | let match_expr = self.expr_match( |
781 | span, | |
782 | poll_expr, | |
dfeec247 | 783 | arena_vec![self; ready_arm, pending_arm], |
416331ca XL |
784 | hir::MatchSource::AwaitDesugar, |
785 | ); | |
786 | self.stmt_expr(span, match_expr) | |
787 | }; | |
788 | ||
ba9703b0 | 789 | // task_context = yield (); |
416331ca XL |
790 | let yield_stmt = { |
791 | let unit = self.expr_unit(span); | |
792 | let yield_expr = self.expr( | |
793 | span, | |
a2a8927a | 794 | hir::ExprKind::Yield(unit, hir::YieldSource::Await { expr: Some(expr_hir_id) }), |
f2b60f7d | 795 | AttrVec::new(), |
416331ca | 796 | ); |
ba9703b0 XL |
797 | let yield_expr = self.arena.alloc(yield_expr); |
798 | ||
799 | if let Some(task_context_hid) = self.task_context { | |
800 | let lhs = self.expr_ident(span, task_context_ident, task_context_hid); | |
94222f64 XL |
801 | let assign = self.expr( |
802 | span, | |
803 | hir::ExprKind::Assign(lhs, yield_expr, self.lower_span(span)), | |
804 | AttrVec::new(), | |
805 | ); | |
ba9703b0 XL |
806 | self.stmt_expr(span, assign) |
807 | } else { | |
808 | // Use of `await` outside of an async context. Return `yield_expr` so that we can | |
809 | // proceed with type checking. | |
810 | self.stmt(span, hir::StmtKind::Semi(yield_expr)) | |
811 | } | |
416331ca XL |
812 | }; |
813 | ||
dfeec247 | 814 | let loop_block = self.block_all(span, arena_vec![self; inner_match_stmt, yield_stmt], None); |
416331ca | 815 | |
e1599b0c | 816 | // loop { .. } |
dfeec247 | 817 | let loop_expr = self.arena.alloc(hir::Expr { |
416331ca | 818 | hir_id: loop_hir_id, |
94222f64 XL |
819 | kind: hir::ExprKind::Loop( |
820 | loop_block, | |
821 | None, | |
822 | hir::LoopSource::Loop, | |
823 | self.lower_span(span), | |
824 | ), | |
825 | span: self.lower_span(span), | |
416331ca XL |
826 | }); |
827 | ||
5e7ed085 FG |
828 | // mut __awaitee => loop { ... } |
829 | let awaitee_arm = self.arm(awaitee_pat, loop_expr); | |
e1599b0c | 830 | |
a2a8927a XL |
831 | // `match ::std::future::IntoFuture::into_future(<expr>) { ... }` |
832 | let into_future_span = self.mark_span_with_reason( | |
833 | DesugaringKind::Await, | |
5099ac24 | 834 | dot_await_span, |
a2a8927a XL |
835 | self.allow_into_future.clone(), |
836 | ); | |
837 | let into_future_expr = self.expr_call_lang_item_fn( | |
838 | into_future_span, | |
839 | hir::LangItem::IntoFutureIntoFuture, | |
840 | arena_vec![self; expr], | |
841 | Some(expr_hir_id), | |
842 | ); | |
843 | ||
844 | // match <into_future_expr> { | |
5e7ed085 | 845 | // mut __awaitee => loop { .. } |
e1599b0c | 846 | // } |
a2a8927a XL |
847 | hir::ExprKind::Match( |
848 | into_future_expr, | |
5e7ed085 | 849 | arena_vec![self; awaitee_arm], |
a2a8927a XL |
850 | hir::MatchSource::AwaitDesugar, |
851 | ) | |
416331ca XL |
852 | } |
853 | ||
854 | fn lower_expr_closure( | |
855 | &mut self, | |
064997fb | 856 | binder: &ClosureBinder, |
416331ca | 857 | capture_clause: CaptureBy, |
923072b8 | 858 | closure_id: NodeId, |
416331ca XL |
859 | movability: Movability, |
860 | decl: &FnDecl, | |
861 | body: &Expr, | |
862 | fn_decl_span: Span, | |
dfeec247 | 863 | ) -> hir::ExprKind<'hir> { |
064997fb FG |
864 | let (binder_clause, generic_params) = self.lower_closure_binder(binder); |
865 | ||
866 | let (body_id, generator_option) = self.with_new_scopes(move |this| { | |
e1599b0c | 867 | let prev = this.current_item; |
416331ca XL |
868 | this.current_item = Some(fn_decl_span); |
869 | let mut generator_kind = None; | |
870 | let body_id = this.lower_fn_body(decl, |this| { | |
dfeec247 | 871 | let e = this.lower_expr_mut(body); |
416331ca XL |
872 | generator_kind = this.generator_kind; |
873 | e | |
874 | }); | |
dfeec247 XL |
875 | let generator_option = |
876 | this.generator_movability_for_fn(&decl, fn_decl_span, generator_kind, movability); | |
e1599b0c | 877 | this.current_item = prev; |
5869c6ff XL |
878 | (body_id, generator_option) |
879 | }); | |
880 | ||
064997fb FG |
881 | let bound_generic_params = self.lower_lifetime_binder(closure_id, generic_params); |
882 | // Lower outside new scope to preserve `is_in_loop_condition`. | |
f2b60f7d | 883 | let fn_decl = self.lower_fn_decl(decl, None, fn_decl_span, FnDeclKind::Closure, None); |
923072b8 | 884 | |
064997fb FG |
885 | let c = self.arena.alloc(hir::Closure { |
886 | binder: binder_clause, | |
887 | capture_clause, | |
888 | bound_generic_params, | |
889 | fn_decl, | |
890 | body: body_id, | |
891 | fn_decl_span: self.lower_span(fn_decl_span), | |
892 | movability: generator_option, | |
893 | }); | |
894 | ||
895 | hir::ExprKind::Closure(c) | |
416331ca XL |
896 | } |
897 | ||
416331ca XL |
898 | fn generator_movability_for_fn( |
899 | &mut self, | |
900 | decl: &FnDecl, | |
901 | fn_decl_span: Span, | |
902 | generator_kind: Option<hir::GeneratorKind>, | |
903 | movability: Movability, | |
60c5eb7d | 904 | ) -> Option<hir::Movability> { |
416331ca | 905 | match generator_kind { |
dfeec247 | 906 | Some(hir::GeneratorKind::Gen) => { |
74b04a01 | 907 | if decl.inputs.len() > 1 { |
f2b60f7d | 908 | self.tcx.sess.emit_err(GeneratorTooManyParameters { fn_decl_span }); |
416331ca | 909 | } |
60c5eb7d | 910 | Some(movability) |
dfeec247 | 911 | } |
e74abb32 | 912 | Some(hir::GeneratorKind::Async(_)) => { |
ba9703b0 | 913 | panic!("non-`async` closure body turned `async` during lowering"); |
dfeec247 | 914 | } |
416331ca XL |
915 | None => { |
916 | if movability == Movability::Static { | |
f2b60f7d | 917 | self.tcx.sess.emit_err(ClosureCannotBeStatic { fn_decl_span }); |
416331ca XL |
918 | } |
919 | None | |
dfeec247 | 920 | } |
416331ca XL |
921 | } |
922 | } | |
923 | ||
064997fb FG |
924 | fn lower_closure_binder<'c>( |
925 | &mut self, | |
926 | binder: &'c ClosureBinder, | |
927 | ) -> (hir::ClosureBinder, &'c [GenericParam]) { | |
928 | let (binder, params) = match binder { | |
929 | ClosureBinder::NotPresent => (hir::ClosureBinder::Default, &[][..]), | |
930 | &ClosureBinder::For { span, ref generic_params } => { | |
931 | let span = self.lower_span(span); | |
932 | (hir::ClosureBinder::For { span }, &**generic_params) | |
933 | } | |
934 | }; | |
935 | ||
936 | (binder, params) | |
937 | } | |
938 | ||
416331ca XL |
939 | fn lower_expr_async_closure( |
940 | &mut self, | |
064997fb | 941 | binder: &ClosureBinder, |
416331ca XL |
942 | capture_clause: CaptureBy, |
943 | closure_id: NodeId, | |
923072b8 | 944 | inner_closure_id: NodeId, |
416331ca XL |
945 | decl: &FnDecl, |
946 | body: &Expr, | |
947 | fn_decl_span: Span, | |
dfeec247 | 948 | ) -> hir::ExprKind<'hir> { |
064997fb | 949 | if let &ClosureBinder::For { span, .. } = binder { |
f2b60f7d | 950 | self.tcx.sess.emit_err(NotSupportedForLifetimeBinderAsyncClosure { span }); |
064997fb FG |
951 | } |
952 | ||
953 | let (binder_clause, generic_params) = self.lower_closure_binder(binder); | |
954 | ||
dfeec247 | 955 | let outer_decl = |
74b04a01 | 956 | FnDecl { inputs: decl.inputs.clone(), output: FnRetTy::Default(fn_decl_span) }; |
416331ca | 957 | |
923072b8 | 958 | let body = self.with_new_scopes(|this| { |
416331ca XL |
959 | // FIXME(cramertj): allow `async` non-`move` closures with arguments. |
960 | if capture_clause == CaptureBy::Ref && !decl.inputs.is_empty() { | |
f2b60f7d | 961 | this.tcx.sess.emit_err(AsyncNonMoveClosureNotSupported { fn_decl_span }); |
416331ca XL |
962 | } |
963 | ||
964 | // Transform `async |x: u8| -> X { ... }` into | |
965 | // `|x: u8| future_from_generator(|| -> X { ... })`. | |
966 | let body_id = this.lower_fn_body(&outer_decl, |this| { | |
dfeec247 | 967 | let async_ret_ty = |
74b04a01 | 968 | if let FnRetTy::Ty(ty) = &decl.output { Some(ty.clone()) } else { None }; |
416331ca | 969 | let async_body = this.make_async_expr( |
e74abb32 | 970 | capture_clause, |
923072b8 | 971 | inner_closure_id, |
e74abb32 XL |
972 | async_ret_ty, |
973 | body.span, | |
974 | hir::AsyncGeneratorKind::Closure, | |
dfeec247 | 975 | |this| this.with_new_scopes(|this| this.lower_expr_mut(body)), |
416331ca | 976 | ); |
f2b60f7d | 977 | this.expr(fn_decl_span, async_body, AttrVec::new()) |
416331ca | 978 | }); |
5869c6ff XL |
979 | body_id |
980 | }); | |
981 | ||
064997fb | 982 | let bound_generic_params = self.lower_lifetime_binder(closure_id, generic_params); |
064997fb FG |
983 | // We need to lower the declaration outside the new scope, because we |
984 | // have to conserve the state of being inside a loop condition for the | |
985 | // closure argument types. | |
f2b60f7d FG |
986 | let fn_decl = |
987 | self.lower_fn_decl(&outer_decl, None, fn_decl_span, FnDeclKind::Closure, None); | |
064997fb FG |
988 | |
989 | let c = self.arena.alloc(hir::Closure { | |
990 | binder: binder_clause, | |
991 | capture_clause, | |
992 | bound_generic_params, | |
993 | fn_decl, | |
994 | body, | |
995 | fn_decl_span: self.lower_span(fn_decl_span), | |
996 | movability: None, | |
997 | }); | |
998 | hir::ExprKind::Closure(c) | |
416331ca XL |
999 | } |
1000 | ||
29967ef6 XL |
1001 | /// Destructure the LHS of complex assignments. |
1002 | /// For instance, lower `(a, b) = t` to `{ let (lhs1, lhs2) = t; a = lhs1; b = lhs2; }`. | |
1003 | fn lower_expr_assign( | |
1004 | &mut self, | |
1005 | lhs: &Expr, | |
1006 | rhs: &Expr, | |
1007 | eq_sign_span: Span, | |
1008 | whole_span: Span, | |
1009 | ) -> hir::ExprKind<'hir> { | |
1010 | // Return early in case of an ordinary assignment. | |
1011 | fn is_ordinary(lower_ctx: &mut LoweringContext<'_, '_>, lhs: &Expr) -> bool { | |
1012 | match &lhs.kind { | |
fc512014 XL |
1013 | ExprKind::Array(..) |
1014 | | ExprKind::Struct(..) | |
1015 | | ExprKind::Tup(..) | |
1016 | | ExprKind::Underscore => false, | |
29967ef6 XL |
1017 | // Check for tuple struct constructor. |
1018 | ExprKind::Call(callee, ..) => lower_ctx.extract_tuple_struct_path(callee).is_none(), | |
1019 | ExprKind::Paren(e) => { | |
1020 | match e.kind { | |
1021 | // We special-case `(..)` for consistency with patterns. | |
1022 | ExprKind::Range(None, None, RangeLimits::HalfOpen) => false, | |
1023 | _ => is_ordinary(lower_ctx, e), | |
1024 | } | |
1025 | } | |
1026 | _ => true, | |
1027 | } | |
1028 | } | |
1029 | if is_ordinary(self, lhs) { | |
94222f64 XL |
1030 | return hir::ExprKind::Assign( |
1031 | self.lower_expr(lhs), | |
1032 | self.lower_expr(rhs), | |
1033 | self.lower_span(eq_sign_span), | |
1034 | ); | |
29967ef6 | 1035 | } |
29967ef6 XL |
1036 | |
1037 | let mut assignments = vec![]; | |
1038 | ||
1039 | // The LHS becomes a pattern: `(lhs1, lhs2)`. | |
1040 | let pat = self.destructure_assign(lhs, eq_sign_span, &mut assignments); | |
1041 | let rhs = self.lower_expr(rhs); | |
1042 | ||
1043 | // Introduce a `let` for destructuring: `let (lhs1, lhs2) = t`. | |
1044 | let destructure_let = self.stmt_let_pat( | |
6a06907d | 1045 | None, |
29967ef6 XL |
1046 | whole_span, |
1047 | Some(rhs), | |
1048 | pat, | |
94222f64 | 1049 | hir::LocalSource::AssignDesugar(self.lower_span(eq_sign_span)), |
29967ef6 XL |
1050 | ); |
1051 | ||
1052 | // `a = lhs1; b = lhs2;`. | |
1053 | let stmts = self | |
1054 | .arena | |
1055 | .alloc_from_iter(std::iter::once(destructure_let).chain(assignments.into_iter())); | |
1056 | ||
1057 | // Wrap everything in a block. | |
1058 | hir::ExprKind::Block(&self.block_all(whole_span, stmts, None), None) | |
1059 | } | |
1060 | ||
1061 | /// If the given expression is a path to a tuple struct, returns that path. | |
1062 | /// It is not a complete check, but just tries to reject most paths early | |
1063 | /// if they are not tuple structs. | |
1064 | /// Type checking will take care of the full validation later. | |
17df50a5 XL |
1065 | fn extract_tuple_struct_path<'a>( |
1066 | &mut self, | |
1067 | expr: &'a Expr, | |
1068 | ) -> Option<(&'a Option<QSelf>, &'a Path)> { | |
1069 | if let ExprKind::Path(qself, path) = &expr.kind { | |
1070 | // Does the path resolve to something disallowed in a tuple struct/variant pattern? | |
29967ef6 | 1071 | if let Some(partial_res) = self.resolver.get_partial_res(expr.id) { |
2b03887a | 1072 | if let Some(res) = partial_res.full_res() && !res.expected_in_tuple_struct_pat() { |
29967ef6 XL |
1073 | return None; |
1074 | } | |
1075 | } | |
17df50a5 | 1076 | return Some((qself, path)); |
29967ef6 XL |
1077 | } |
1078 | None | |
1079 | } | |
1080 | ||
04454e1e FG |
1081 | /// If the given expression is a path to a unit struct, returns that path. |
1082 | /// It is not a complete check, but just tries to reject most paths early | |
1083 | /// if they are not unit structs. | |
1084 | /// Type checking will take care of the full validation later. | |
1085 | fn extract_unit_struct_path<'a>( | |
1086 | &mut self, | |
1087 | expr: &'a Expr, | |
1088 | ) -> Option<(&'a Option<QSelf>, &'a Path)> { | |
1089 | if let ExprKind::Path(qself, path) = &expr.kind { | |
1090 | // Does the path resolve to something disallowed in a unit struct/variant pattern? | |
1091 | if let Some(partial_res) = self.resolver.get_partial_res(expr.id) { | |
2b03887a | 1092 | if let Some(res) = partial_res.full_res() && !res.expected_in_unit_struct_pat() { |
04454e1e FG |
1093 | return None; |
1094 | } | |
1095 | } | |
1096 | return Some((qself, path)); | |
1097 | } | |
1098 | None | |
1099 | } | |
1100 | ||
29967ef6 XL |
1101 | /// Convert the LHS of a destructuring assignment to a pattern. |
1102 | /// Each sub-assignment is recorded in `assignments`. | |
1103 | fn destructure_assign( | |
1104 | &mut self, | |
1105 | lhs: &Expr, | |
1106 | eq_sign_span: Span, | |
1107 | assignments: &mut Vec<hir::Stmt<'hir>>, | |
1108 | ) -> &'hir hir::Pat<'hir> { | |
136023e0 XL |
1109 | self.arena.alloc(self.destructure_assign_mut(lhs, eq_sign_span, assignments)) |
1110 | } | |
1111 | ||
1112 | fn destructure_assign_mut( | |
1113 | &mut self, | |
1114 | lhs: &Expr, | |
1115 | eq_sign_span: Span, | |
1116 | assignments: &mut Vec<hir::Stmt<'hir>>, | |
1117 | ) -> hir::Pat<'hir> { | |
29967ef6 | 1118 | match &lhs.kind { |
fc512014 XL |
1119 | // Underscore pattern. |
1120 | ExprKind::Underscore => { | |
1121 | return self.pat_without_dbm(lhs.span, hir::PatKind::Wild); | |
1122 | } | |
29967ef6 XL |
1123 | // Slice patterns. |
1124 | ExprKind::Array(elements) => { | |
1125 | let (pats, rest) = | |
1126 | self.destructure_sequence(elements, "slice", eq_sign_span, assignments); | |
1127 | let slice_pat = if let Some((i, span)) = rest { | |
1128 | let (before, after) = pats.split_at(i); | |
1129 | hir::PatKind::Slice( | |
1130 | before, | |
136023e0 | 1131 | Some(self.arena.alloc(self.pat_without_dbm(span, hir::PatKind::Wild))), |
29967ef6 XL |
1132 | after, |
1133 | ) | |
1134 | } else { | |
1135 | hir::PatKind::Slice(pats, None, &[]) | |
1136 | }; | |
1137 | return self.pat_without_dbm(lhs.span, slice_pat); | |
1138 | } | |
1139 | // Tuple structs. | |
1140 | ExprKind::Call(callee, args) => { | |
17df50a5 | 1141 | if let Some((qself, path)) = self.extract_tuple_struct_path(callee) { |
29967ef6 XL |
1142 | let (pats, rest) = self.destructure_sequence( |
1143 | args, | |
1144 | "tuple struct or variant", | |
1145 | eq_sign_span, | |
1146 | assignments, | |
1147 | ); | |
1148 | let qpath = self.lower_qpath( | |
1149 | callee.id, | |
17df50a5 | 1150 | qself, |
29967ef6 XL |
1151 | path, |
1152 | ParamMode::Optional, | |
f2b60f7d | 1153 | &ImplTraitContext::Disallowed(ImplTraitPosition::Path), |
29967ef6 XL |
1154 | ); |
1155 | // Destructure like a tuple struct. | |
f2b60f7d FG |
1156 | let tuple_struct_pat = hir::PatKind::TupleStruct( |
1157 | qpath, | |
1158 | pats, | |
1159 | hir::DotDotPos::new(rest.map(|r| r.0)), | |
1160 | ); | |
29967ef6 XL |
1161 | return self.pat_without_dbm(lhs.span, tuple_struct_pat); |
1162 | } | |
1163 | } | |
04454e1e FG |
1164 | // Unit structs and enum variants. |
1165 | ExprKind::Path(..) => { | |
1166 | if let Some((qself, path)) = self.extract_unit_struct_path(lhs) { | |
1167 | let qpath = self.lower_qpath( | |
1168 | lhs.id, | |
1169 | qself, | |
1170 | path, | |
1171 | ParamMode::Optional, | |
f2b60f7d | 1172 | &ImplTraitContext::Disallowed(ImplTraitPosition::Path), |
04454e1e FG |
1173 | ); |
1174 | // Destructure like a unit struct. | |
1175 | let unit_struct_pat = hir::PatKind::Path(qpath); | |
1176 | return self.pat_without_dbm(lhs.span, unit_struct_pat); | |
1177 | } | |
1178 | } | |
29967ef6 | 1179 | // Structs. |
6a06907d XL |
1180 | ExprKind::Struct(se) => { |
1181 | let field_pats = self.arena.alloc_from_iter(se.fields.iter().map(|f| { | |
29967ef6 | 1182 | let pat = self.destructure_assign(&f.expr, eq_sign_span, assignments); |
6a06907d | 1183 | hir::PatField { |
29967ef6 | 1184 | hir_id: self.next_id(), |
94222f64 | 1185 | ident: self.lower_ident(f.ident), |
29967ef6 XL |
1186 | pat, |
1187 | is_shorthand: f.is_shorthand, | |
94222f64 | 1188 | span: self.lower_span(f.span), |
29967ef6 XL |
1189 | } |
1190 | })); | |
1191 | let qpath = self.lower_qpath( | |
1192 | lhs.id, | |
17df50a5 | 1193 | &se.qself, |
6a06907d | 1194 | &se.path, |
29967ef6 | 1195 | ParamMode::Optional, |
f2b60f7d | 1196 | &ImplTraitContext::Disallowed(ImplTraitPosition::Path), |
29967ef6 | 1197 | ); |
6a06907d | 1198 | let fields_omitted = match &se.rest { |
29967ef6 | 1199 | StructRest::Base(e) => { |
f2b60f7d FG |
1200 | self.tcx.sess.emit_err(FunctionalRecordUpdateDestructuringAssignemnt { |
1201 | span: e.span, | |
1202 | }); | |
29967ef6 XL |
1203 | true |
1204 | } | |
1205 | StructRest::Rest(_) => true, | |
1206 | StructRest::None => false, | |
1207 | }; | |
1208 | let struct_pat = hir::PatKind::Struct(qpath, field_pats, fields_omitted); | |
1209 | return self.pat_without_dbm(lhs.span, struct_pat); | |
1210 | } | |
1211 | // Tuples. | |
1212 | ExprKind::Tup(elements) => { | |
1213 | let (pats, rest) = | |
1214 | self.destructure_sequence(elements, "tuple", eq_sign_span, assignments); | |
f2b60f7d | 1215 | let tuple_pat = hir::PatKind::Tuple(pats, hir::DotDotPos::new(rest.map(|r| r.0))); |
29967ef6 XL |
1216 | return self.pat_without_dbm(lhs.span, tuple_pat); |
1217 | } | |
1218 | ExprKind::Paren(e) => { | |
1219 | // We special-case `(..)` for consistency with patterns. | |
1220 | if let ExprKind::Range(None, None, RangeLimits::HalfOpen) = e.kind { | |
f2b60f7d | 1221 | let tuple_pat = hir::PatKind::Tuple(&[], hir::DotDotPos::new(Some(0))); |
29967ef6 XL |
1222 | return self.pat_without_dbm(lhs.span, tuple_pat); |
1223 | } else { | |
136023e0 | 1224 | return self.destructure_assign_mut(e, eq_sign_span, assignments); |
29967ef6 XL |
1225 | } |
1226 | } | |
1227 | _ => {} | |
1228 | } | |
1229 | // Treat all other cases as normal lvalue. | |
94222f64 | 1230 | let ident = Ident::new(sym::lhs, self.lower_span(lhs.span)); |
136023e0 | 1231 | let (pat, binding) = self.pat_ident_mut(lhs.span, ident); |
29967ef6 | 1232 | let ident = self.expr_ident(lhs.span, ident, binding); |
94222f64 XL |
1233 | let assign = |
1234 | hir::ExprKind::Assign(self.lower_expr(lhs), ident, self.lower_span(eq_sign_span)); | |
f2b60f7d | 1235 | let expr = self.expr(lhs.span, assign, AttrVec::new()); |
29967ef6 XL |
1236 | assignments.push(self.stmt_expr(lhs.span, expr)); |
1237 | pat | |
1238 | } | |
1239 | ||
1240 | /// Destructure a sequence of expressions occurring on the LHS of an assignment. | |
1241 | /// Such a sequence occurs in a tuple (struct)/slice. | |
1242 | /// Return a sequence of corresponding patterns, and the index and the span of `..` if it | |
1243 | /// exists. | |
1244 | /// Each sub-assignment is recorded in `assignments`. | |
1245 | fn destructure_sequence( | |
1246 | &mut self, | |
1247 | elements: &[AstP<Expr>], | |
1248 | ctx: &str, | |
1249 | eq_sign_span: Span, | |
1250 | assignments: &mut Vec<hir::Stmt<'hir>>, | |
136023e0 | 1251 | ) -> (&'hir [hir::Pat<'hir>], Option<(usize, Span)>) { |
29967ef6 XL |
1252 | let mut rest = None; |
1253 | let elements = | |
1254 | self.arena.alloc_from_iter(elements.iter().enumerate().filter_map(|(i, e)| { | |
1255 | // Check for `..` pattern. | |
1256 | if let ExprKind::Range(None, None, RangeLimits::HalfOpen) = e.kind { | |
1257 | if let Some((_, prev_span)) = rest { | |
1258 | self.ban_extra_rest_pat(e.span, prev_span, ctx); | |
1259 | } else { | |
1260 | rest = Some((i, e.span)); | |
1261 | } | |
1262 | None | |
1263 | } else { | |
136023e0 | 1264 | Some(self.destructure_assign_mut(e, eq_sign_span, assignments)) |
29967ef6 XL |
1265 | } |
1266 | })); | |
1267 | (elements, rest) | |
1268 | } | |
1269 | ||
416331ca | 1270 | /// Desugar `<start>..=<end>` into `std::ops::RangeInclusive::new(<start>, <end>)`. |
dfeec247 | 1271 | fn lower_expr_range_closed(&mut self, span: Span, e1: &Expr, e2: &Expr) -> hir::ExprKind<'hir> { |
dfeec247 XL |
1272 | let e1 = self.lower_expr_mut(e1); |
1273 | let e2 = self.lower_expr_mut(e2); | |
a2a8927a XL |
1274 | let fn_path = |
1275 | hir::QPath::LangItem(hir::LangItem::RangeInclusiveNew, self.lower_span(span), None); | |
3dfed10e | 1276 | let fn_expr = |
f2b60f7d | 1277 | self.arena.alloc(self.expr(span, hir::ExprKind::Path(fn_path), AttrVec::new())); |
3dfed10e | 1278 | hir::ExprKind::Call(fn_expr, arena_vec![self; e1, e2]) |
416331ca XL |
1279 | } |
1280 | ||
1281 | fn lower_expr_range( | |
1282 | &mut self, | |
1283 | span: Span, | |
1284 | e1: Option<&Expr>, | |
1285 | e2: Option<&Expr>, | |
1286 | lims: RangeLimits, | |
dfeec247 | 1287 | ) -> hir::ExprKind<'hir> { |
3dfed10e XL |
1288 | use rustc_ast::RangeLimits::*; |
1289 | ||
1290 | let lang_item = match (e1, e2, lims) { | |
1291 | (None, None, HalfOpen) => hir::LangItem::RangeFull, | |
1292 | (Some(..), None, HalfOpen) => hir::LangItem::RangeFrom, | |
1293 | (None, Some(..), HalfOpen) => hir::LangItem::RangeTo, | |
1294 | (Some(..), Some(..), HalfOpen) => hir::LangItem::Range, | |
1295 | (None, Some(..), Closed) => hir::LangItem::RangeToInclusive, | |
416331ca | 1296 | (Some(..), Some(..), Closed) => unreachable!(), |
f2b60f7d FG |
1297 | (start, None, Closed) => { |
1298 | self.tcx.sess.emit_err(InclusiveRangeWithNoEnd { span }); | |
1299 | match start { | |
1300 | Some(..) => hir::LangItem::RangeFrom, | |
1301 | None => hir::LangItem::RangeFull, | |
1302 | } | |
1303 | } | |
416331ca XL |
1304 | }; |
1305 | ||
dfeec247 | 1306 | let fields = self.arena.alloc_from_iter( |
5099ac24 FG |
1307 | e1.iter().map(|e| (sym::start, e)).chain(e2.iter().map(|e| (sym::end, e))).map( |
1308 | |(s, e)| { | |
1309 | let expr = self.lower_expr(&e); | |
1310 | let ident = Ident::new(s, self.lower_span(e.span)); | |
1311 | self.expr_field(ident, expr, e.span) | |
1312 | }, | |
1313 | ), | |
dfeec247 | 1314 | ); |
416331ca | 1315 | |
94222f64 | 1316 | hir::ExprKind::Struct( |
a2a8927a | 1317 | self.arena.alloc(hir::QPath::LangItem(lang_item, self.lower_span(span), None)), |
94222f64 XL |
1318 | fields, |
1319 | None, | |
1320 | ) | |
1321 | } | |
1322 | ||
1323 | fn lower_label(&self, opt_label: Option<Label>) -> Option<Label> { | |
1324 | let label = opt_label?; | |
1325 | Some(Label { ident: self.lower_ident(label.ident) }) | |
416331ca XL |
1326 | } |
1327 | ||
416331ca XL |
1328 | fn lower_loop_destination(&mut self, destination: Option<(NodeId, Label)>) -> hir::Destination { |
1329 | let target_id = match destination { | |
1330 | Some((id, _)) => { | |
1331 | if let Some(loop_id) = self.resolver.get_label_res(id) { | |
1332 | Ok(self.lower_node_id(loop_id)) | |
1333 | } else { | |
1334 | Err(hir::LoopIdError::UnresolvedLabel) | |
1335 | } | |
1336 | } | |
dfeec247 | 1337 | None => self |
c295e0f8 | 1338 | .loop_scope |
dfeec247 | 1339 | .map(|id| Ok(self.lower_node_id(id))) |
74b04a01 | 1340 | .unwrap_or(Err(hir::LoopIdError::OutsideLoopScope)), |
416331ca | 1341 | }; |
94222f64 XL |
1342 | let label = self.lower_label(destination.map(|(_, label)| label)); |
1343 | hir::Destination { label, target_id } | |
416331ca XL |
1344 | } |
1345 | ||
1346 | fn lower_jump_destination(&mut self, id: NodeId, opt_label: Option<Label>) -> hir::Destination { | |
1347 | if self.is_in_loop_condition && opt_label.is_none() { | |
1348 | hir::Destination { | |
1349 | label: None, | |
74b04a01 | 1350 | target_id: Err(hir::LoopIdError::UnlabeledCfInWhileCondition), |
416331ca XL |
1351 | } |
1352 | } else { | |
1353 | self.lower_loop_destination(opt_label.map(|label| (id, label))) | |
1354 | } | |
1355 | } | |
1356 | ||
dfeec247 | 1357 | fn with_catch_scope<T>(&mut self, catch_id: NodeId, f: impl FnOnce(&mut Self) -> T) -> T { |
c295e0f8 | 1358 | let old_scope = self.catch_scope.replace(catch_id); |
416331ca | 1359 | let result = f(self); |
c295e0f8 | 1360 | self.catch_scope = old_scope; |
416331ca XL |
1361 | result |
1362 | } | |
1363 | ||
dfeec247 | 1364 | fn with_loop_scope<T>(&mut self, loop_id: NodeId, f: impl FnOnce(&mut Self) -> T) -> T { |
416331ca XL |
1365 | // We're no longer in the base loop's condition; we're in another loop. |
1366 | let was_in_loop_condition = self.is_in_loop_condition; | |
1367 | self.is_in_loop_condition = false; | |
1368 | ||
c295e0f8 | 1369 | let old_scope = self.loop_scope.replace(loop_id); |
416331ca | 1370 | let result = f(self); |
c295e0f8 | 1371 | self.loop_scope = old_scope; |
416331ca XL |
1372 | |
1373 | self.is_in_loop_condition = was_in_loop_condition; | |
1374 | ||
1375 | result | |
1376 | } | |
1377 | ||
dfeec247 | 1378 | fn with_loop_condition_scope<T>(&mut self, f: impl FnOnce(&mut Self) -> T) -> T { |
416331ca XL |
1379 | let was_in_loop_condition = self.is_in_loop_condition; |
1380 | self.is_in_loop_condition = true; | |
1381 | ||
1382 | let result = f(self); | |
1383 | ||
1384 | self.is_in_loop_condition = was_in_loop_condition; | |
1385 | ||
1386 | result | |
1387 | } | |
1388 | ||
6a06907d | 1389 | fn lower_expr_field(&mut self, f: &ExprField) -> hir::ExprField<'hir> { |
f2b60f7d FG |
1390 | let hir_id = self.lower_node_id(f.id); |
1391 | self.lower_attrs(hir_id, &f.attrs); | |
6a06907d | 1392 | hir::ExprField { |
f2b60f7d | 1393 | hir_id, |
94222f64 | 1394 | ident: self.lower_ident(f.ident), |
dfeec247 | 1395 | expr: self.lower_expr(&f.expr), |
94222f64 | 1396 | span: self.lower_span(f.span), |
416331ca XL |
1397 | is_shorthand: f.is_shorthand, |
1398 | } | |
1399 | } | |
1400 | ||
dfeec247 | 1401 | fn lower_expr_yield(&mut self, span: Span, opt_expr: Option<&Expr>) -> hir::ExprKind<'hir> { |
416331ca | 1402 | match self.generator_kind { |
dfeec247 | 1403 | Some(hir::GeneratorKind::Gen) => {} |
e74abb32 | 1404 | Some(hir::GeneratorKind::Async(_)) => { |
f2b60f7d | 1405 | self.tcx.sess.emit_err(AsyncGeneratorsNotSupported { span }); |
dfeec247 | 1406 | } |
416331ca XL |
1407 | None => self.generator_kind = Some(hir::GeneratorKind::Gen), |
1408 | } | |
1409 | ||
dfeec247 XL |
1410 | let expr = |
1411 | opt_expr.as_ref().map(|x| self.lower_expr(x)).unwrap_or_else(|| self.expr_unit(span)); | |
416331ca | 1412 | |
dfeec247 | 1413 | hir::ExprKind::Yield(expr, hir::YieldSource::Yield) |
416331ca XL |
1414 | } |
1415 | ||
1416 | /// Desugar `ExprForLoop` from: `[opt_ident]: for <pat> in <head> <body>` into: | |
04454e1e | 1417 | /// ```ignore (pseudo-rust) |
416331ca | 1418 | /// { |
3c0e092e | 1419 | /// let result = match IntoIterator::into_iter(<head>) { |
416331ca XL |
1420 | /// mut iter => { |
1421 | /// [opt_ident]: loop { | |
3c0e092e XL |
1422 | /// match Iterator::next(&mut iter) { |
1423 | /// None => break, | |
1424 | /// Some(<pat>) => <body>, | |
416331ca | 1425 | /// }; |
416331ca XL |
1426 | /// } |
1427 | /// } | |
1428 | /// }; | |
1429 | /// result | |
1430 | /// } | |
1431 | /// ``` | |
1432 | fn lower_expr_for( | |
1433 | &mut self, | |
1434 | e: &Expr, | |
1435 | pat: &Pat, | |
1436 | head: &Expr, | |
1437 | body: &Block, | |
1438 | opt_label: Option<Label>, | |
dfeec247 | 1439 | ) -> hir::Expr<'hir> { |
3c0e092e XL |
1440 | let head = self.lower_expr_mut(head); |
1441 | let pat = self.lower_pat(pat); | |
1442 | let for_span = | |
1443 | self.mark_span_with_reason(DesugaringKind::ForLoop, self.lower_span(e.span), None); | |
1444 | let head_span = self.mark_span_with_reason(DesugaringKind::ForLoop, head.span, None); | |
1445 | let pat_span = self.mark_span_with_reason(DesugaringKind::ForLoop, pat.span, None); | |
416331ca | 1446 | |
3c0e092e XL |
1447 | // `None => break` |
1448 | let none_arm = { | |
416331ca | 1449 | let break_expr = |
f2b60f7d | 1450 | self.with_loop_scope(e.id, |this| this.expr_break_alloc(for_span, AttrVec::new())); |
3c0e092e | 1451 | let pat = self.pat_none(for_span); |
e74abb32 | 1452 | self.arm(pat, break_expr) |
416331ca XL |
1453 | }; |
1454 | ||
3c0e092e XL |
1455 | // Some(<pat>) => <body>, |
1456 | let some_arm = { | |
1457 | let some_pat = self.pat_some(pat_span, pat); | |
1458 | let body_block = self.with_loop_scope(e.id, |this| this.lower_block(body, false)); | |
f2b60f7d | 1459 | let body_expr = self.arena.alloc(self.expr_block(body_block, AttrVec::new())); |
3c0e092e XL |
1460 | self.arm(some_pat, body_expr) |
1461 | }; | |
1462 | ||
416331ca | 1463 | // `mut iter` |
3c0e092e | 1464 | let iter = Ident::with_dummy_span(sym::iter); |
dfeec247 | 1465 | let (iter_pat, iter_pat_nid) = |
f2b60f7d | 1466 | self.pat_ident_binding_mode(head_span, iter, hir::BindingAnnotation::MUT); |
416331ca | 1467 | |
3c0e092e | 1468 | // `match Iterator::next(&mut iter) { ... }` |
416331ca | 1469 | let match_expr = { |
3c0e092e XL |
1470 | let iter = self.expr_ident(head_span, iter, iter_pat_nid); |
1471 | let ref_mut_iter = self.expr_mut_addr_of(head_span, iter); | |
3dfed10e | 1472 | let next_expr = self.expr_call_lang_item_fn( |
3c0e092e | 1473 | head_span, |
3dfed10e XL |
1474 | hir::LangItem::IteratorNext, |
1475 | arena_vec![self; ref_mut_iter], | |
a2a8927a | 1476 | None, |
3dfed10e | 1477 | ); |
3c0e092e | 1478 | let arms = arena_vec![self; none_arm, some_arm]; |
416331ca | 1479 | |
3c0e092e | 1480 | self.expr_match(head_span, next_expr, arms, hir::MatchSource::ForLoopDesugar) |
416331ca | 1481 | }; |
3c0e092e | 1482 | let match_stmt = self.stmt_expr(for_span, match_expr); |
416331ca | 1483 | |
3c0e092e | 1484 | let loop_block = self.block_all(for_span, arena_vec![self; match_stmt], None); |
416331ca XL |
1485 | |
1486 | // `[opt_ident]: loop { ... }` | |
5869c6ff XL |
1487 | let kind = hir::ExprKind::Loop( |
1488 | loop_block, | |
94222f64 | 1489 | self.lower_label(opt_label), |
5869c6ff | 1490 | hir::LoopSource::ForLoop, |
3c0e092e | 1491 | self.lower_span(for_span.with_hi(head.span.hi())), |
5869c6ff | 1492 | ); |
3c0e092e XL |
1493 | let loop_expr = |
1494 | self.arena.alloc(hir::Expr { hir_id: self.lower_node_id(e.id), kind, span: for_span }); | |
416331ca XL |
1495 | |
1496 | // `mut iter => { ... }` | |
e74abb32 | 1497 | let iter_arm = self.arm(iter_pat, loop_expr); |
416331ca XL |
1498 | |
1499 | // `match ::std::iter::IntoIterator::into_iter(<head>) { ... }` | |
1500 | let into_iter_expr = { | |
3dfed10e | 1501 | self.expr_call_lang_item_fn( |
3c0e092e | 1502 | head_span, |
3dfed10e XL |
1503 | hir::LangItem::IntoIterIntoIter, |
1504 | arena_vec![self; head], | |
a2a8927a | 1505 | None, |
3dfed10e | 1506 | ) |
416331ca XL |
1507 | }; |
1508 | ||
dfeec247 | 1509 | let match_expr = self.arena.alloc(self.expr_match( |
3c0e092e | 1510 | for_span, |
416331ca | 1511 | into_iter_expr, |
dfeec247 | 1512 | arena_vec![self; iter_arm], |
416331ca XL |
1513 | hir::MatchSource::ForLoopDesugar, |
1514 | )); | |
1515 | ||
1516 | // This is effectively `{ let _result = ...; _result }`. | |
1517 | // The construct was introduced in #21984 and is necessary to make sure that | |
1518 | // temporaries in the `head` expression are dropped and do not leak to the | |
1519 | // surrounding scope of the `match` since the `match` is not a terminating scope. | |
1520 | // | |
1521 | // Also, add the attributes to the outer returned expr node. | |
f2b60f7d | 1522 | self.expr_drop_temps_mut(for_span, match_expr, e.attrs.clone()) |
416331ca XL |
1523 | } |
1524 | ||
1525 | /// Desugar `ExprKind::Try` from: `<expr>?` into: | |
04454e1e | 1526 | /// ```ignore (pseudo-rust) |
136023e0 XL |
1527 | /// match Try::branch(<expr>) { |
1528 | /// ControlFlow::Continue(val) => #[allow(unreachable_code)] val,, | |
1529 | /// ControlFlow::Break(residual) => | |
1530 | /// #[allow(unreachable_code)] | |
1531 | /// // If there is an enclosing `try {...}`: | |
1532 | /// break 'catch_target Try::from_residual(residual), | |
1533 | /// // Otherwise: | |
1534 | /// return Try::from_residual(residual), | |
416331ca XL |
1535 | /// } |
1536 | /// ``` | |
dfeec247 | 1537 | fn lower_expr_try(&mut self, span: Span, sub_expr: &Expr) -> hir::ExprKind<'hir> { |
416331ca XL |
1538 | let unstable_span = self.mark_span_with_reason( |
1539 | DesugaringKind::QuestionMark, | |
1540 | span, | |
1541 | self.allow_try_trait.clone(), | |
1542 | ); | |
064997fb | 1543 | let try_span = self.tcx.sess.source_map().end_point(span); |
416331ca XL |
1544 | let try_span = self.mark_span_with_reason( |
1545 | DesugaringKind::QuestionMark, | |
1546 | try_span, | |
1547 | self.allow_try_trait.clone(), | |
1548 | ); | |
1549 | ||
17df50a5 | 1550 | // `Try::branch(<expr>)` |
416331ca XL |
1551 | let scrutinee = { |
1552 | // expand <expr> | |
dfeec247 | 1553 | let sub_expr = self.lower_expr_mut(sub_expr); |
416331ca | 1554 | |
3dfed10e XL |
1555 | self.expr_call_lang_item_fn( |
1556 | unstable_span, | |
17df50a5 | 1557 | hir::LangItem::TryTraitBranch, |
3dfed10e | 1558 | arena_vec![self; sub_expr], |
a2a8927a | 1559 | None, |
3dfed10e | 1560 | ) |
416331ca XL |
1561 | }; |
1562 | ||
1563 | // `#[allow(unreachable_code)]` | |
1564 | let attr = { | |
1565 | // `allow(unreachable_code)` | |
1566 | let allow = { | |
94222f64 XL |
1567 | let allow_ident = Ident::new(sym::allow, self.lower_span(span)); |
1568 | let uc_ident = Ident::new(sym::unreachable_code, self.lower_span(span)); | |
416331ca XL |
1569 | let uc_nested = attr::mk_nested_word_item(uc_ident); |
1570 | attr::mk_list_item(allow_ident, vec![uc_nested]) | |
1571 | }; | |
f2b60f7d | 1572 | attr::mk_attr_outer(&self.tcx.sess.parse_sess.attr_id_generator, allow) |
416331ca | 1573 | }; |
f2b60f7d | 1574 | let attrs: AttrVec = thin_vec![attr]; |
416331ca | 1575 | |
17df50a5 XL |
1576 | // `ControlFlow::Continue(val) => #[allow(unreachable_code)] val,` |
1577 | let continue_arm = { | |
e1599b0c | 1578 | let val_ident = Ident::with_dummy_span(sym::val); |
416331ca | 1579 | let (val_pat, val_pat_nid) = self.pat_ident(span, val_ident); |
dfeec247 | 1580 | let val_expr = self.arena.alloc(self.expr_ident_with_attrs( |
416331ca XL |
1581 | span, |
1582 | val_ident, | |
1583 | val_pat_nid, | |
f2b60f7d | 1584 | attrs.clone(), |
416331ca | 1585 | )); |
17df50a5 XL |
1586 | let continue_pat = self.pat_cf_continue(unstable_span, val_pat); |
1587 | self.arm(continue_pat, val_expr) | |
416331ca XL |
1588 | }; |
1589 | ||
17df50a5 XL |
1590 | // `ControlFlow::Break(residual) => |
1591 | // #[allow(unreachable_code)] | |
1592 | // return Try::from_residual(residual),` | |
1593 | let break_arm = { | |
1594 | let residual_ident = Ident::with_dummy_span(sym::residual); | |
1595 | let (residual_local, residual_local_nid) = self.pat_ident(try_span, residual_ident); | |
1596 | let residual_expr = self.expr_ident_mut(try_span, residual_ident, residual_local_nid); | |
1597 | let from_residual_expr = self.wrap_in_try_constructor( | |
1598 | hir::LangItem::TryTraitFromResidual, | |
1599 | try_span, | |
1600 | self.arena.alloc(residual_expr), | |
29967ef6 | 1601 | unstable_span, |
3dfed10e | 1602 | ); |
c295e0f8 | 1603 | let ret_expr = if let Some(catch_node) = self.catch_scope { |
416331ca | 1604 | let target_id = Ok(self.lower_node_id(catch_node)); |
dfeec247 | 1605 | self.arena.alloc(self.expr( |
416331ca XL |
1606 | try_span, |
1607 | hir::ExprKind::Break( | |
dfeec247 | 1608 | hir::Destination { label: None, target_id }, |
17df50a5 | 1609 | Some(from_residual_expr), |
416331ca | 1610 | ), |
f2b60f7d | 1611 | attrs, |
416331ca XL |
1612 | )) |
1613 | } else { | |
dfeec247 XL |
1614 | self.arena.alloc(self.expr( |
1615 | try_span, | |
17df50a5 | 1616 | hir::ExprKind::Ret(Some(from_residual_expr)), |
f2b60f7d | 1617 | attrs, |
dfeec247 | 1618 | )) |
416331ca XL |
1619 | }; |
1620 | ||
17df50a5 XL |
1621 | let break_pat = self.pat_cf_break(try_span, residual_local); |
1622 | self.arm(break_pat, ret_expr) | |
416331ca XL |
1623 | }; |
1624 | ||
1625 | hir::ExprKind::Match( | |
1626 | scrutinee, | |
17df50a5 | 1627 | arena_vec![self; break_arm, continue_arm], |
416331ca XL |
1628 | hir::MatchSource::TryDesugar, |
1629 | ) | |
1630 | } | |
1631 | ||
04454e1e | 1632 | /// Desugar `ExprKind::Yeet` from: `do yeet <expr>` into: |
2b03887a | 1633 | /// ```ignore(illustrative) |
04454e1e | 1634 | /// // If there is an enclosing `try {...}`: |
2b03887a | 1635 | /// break 'catch_target FromResidual::from_residual(Yeet(residual)); |
04454e1e | 1636 | /// // Otherwise: |
2b03887a | 1637 | /// return FromResidual::from_residual(Yeet(residual)); |
04454e1e FG |
1638 | /// ``` |
1639 | /// But to simplify this, there's a `from_yeet` lang item function which | |
1640 | /// handles the combined `FromResidual::from_residual(Yeet(residual))`. | |
1641 | fn lower_expr_yeet(&mut self, span: Span, sub_expr: Option<&Expr>) -> hir::ExprKind<'hir> { | |
1642 | // The expression (if present) or `()` otherwise. | |
1643 | let (yeeted_span, yeeted_expr) = if let Some(sub_expr) = sub_expr { | |
1644 | (sub_expr.span, self.lower_expr(sub_expr)) | |
1645 | } else { | |
1646 | (self.mark_span_with_reason(DesugaringKind::YeetExpr, span, None), self.expr_unit(span)) | |
1647 | }; | |
1648 | ||
1649 | let unstable_span = self.mark_span_with_reason( | |
1650 | DesugaringKind::YeetExpr, | |
1651 | span, | |
1652 | self.allow_try_trait.clone(), | |
1653 | ); | |
1654 | ||
1655 | let from_yeet_expr = self.wrap_in_try_constructor( | |
1656 | hir::LangItem::TryTraitFromYeet, | |
1657 | unstable_span, | |
1658 | yeeted_expr, | |
1659 | yeeted_span, | |
1660 | ); | |
1661 | ||
1662 | if let Some(catch_node) = self.catch_scope { | |
1663 | let target_id = Ok(self.lower_node_id(catch_node)); | |
1664 | hir::ExprKind::Break(hir::Destination { label: None, target_id }, Some(from_yeet_expr)) | |
1665 | } else { | |
1666 | hir::ExprKind::Ret(Some(from_yeet_expr)) | |
1667 | } | |
1668 | } | |
1669 | ||
416331ca XL |
1670 | // ========================================================================= |
1671 | // Helper methods for building HIR. | |
1672 | // ========================================================================= | |
1673 | ||
416331ca XL |
1674 | /// Wrap the given `expr` in a terminating scope using `hir::ExprKind::DropTemps`. |
1675 | /// | |
1676 | /// In terms of drop order, it has the same effect as wrapping `expr` in | |
1677 | /// `{ let _t = $expr; _t }` but should provide better compile-time performance. | |
1678 | /// | |
1679 | /// The drop order can be important in e.g. `if expr { .. }`. | |
e1599b0c | 1680 | pub(super) fn expr_drop_temps( |
416331ca XL |
1681 | &mut self, |
1682 | span: Span, | |
dfeec247 XL |
1683 | expr: &'hir hir::Expr<'hir>, |
1684 | attrs: AttrVec, | |
1685 | ) -> &'hir hir::Expr<'hir> { | |
1686 | self.arena.alloc(self.expr_drop_temps_mut(span, expr, attrs)) | |
1687 | } | |
1688 | ||
1689 | pub(super) fn expr_drop_temps_mut( | |
1690 | &mut self, | |
1691 | span: Span, | |
1692 | expr: &'hir hir::Expr<'hir>, | |
1693 | attrs: AttrVec, | |
1694 | ) -> hir::Expr<'hir> { | |
416331ca XL |
1695 | self.expr(span, hir::ExprKind::DropTemps(expr), attrs) |
1696 | } | |
1697 | ||
1698 | fn expr_match( | |
1699 | &mut self, | |
1700 | span: Span, | |
dfeec247 XL |
1701 | arg: &'hir hir::Expr<'hir>, |
1702 | arms: &'hir [hir::Arm<'hir>], | |
416331ca | 1703 | source: hir::MatchSource, |
dfeec247 | 1704 | ) -> hir::Expr<'hir> { |
f2b60f7d | 1705 | self.expr(span, hir::ExprKind::Match(arg, arms, source), AttrVec::new()) |
416331ca XL |
1706 | } |
1707 | ||
94222f64 | 1708 | fn expr_break(&mut self, span: Span, attrs: AttrVec) -> hir::Expr<'hir> { |
416331ca | 1709 | let expr_break = hir::ExprKind::Break(self.lower_loop_destination(None), None); |
94222f64 XL |
1710 | self.expr(span, expr_break, attrs) |
1711 | } | |
1712 | ||
1713 | fn expr_break_alloc(&mut self, span: Span, attrs: AttrVec) -> &'hir hir::Expr<'hir> { | |
1714 | let expr_break = self.expr_break(span, attrs); | |
1715 | self.arena.alloc(expr_break) | |
416331ca XL |
1716 | } |
1717 | ||
dfeec247 | 1718 | fn expr_mut_addr_of(&mut self, span: Span, e: &'hir hir::Expr<'hir>) -> hir::Expr<'hir> { |
60c5eb7d XL |
1719 | self.expr( |
1720 | span, | |
dfeec247 | 1721 | hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Mut, e), |
f2b60f7d | 1722 | AttrVec::new(), |
60c5eb7d | 1723 | ) |
416331ca XL |
1724 | } |
1725 | ||
dfeec247 | 1726 | fn expr_unit(&mut self, sp: Span) -> &'hir hir::Expr<'hir> { |
f2b60f7d | 1727 | self.arena.alloc(self.expr(sp, hir::ExprKind::Tup(&[]), AttrVec::new())) |
416331ca XL |
1728 | } |
1729 | ||
ba9703b0 XL |
1730 | fn expr_call_mut( |
1731 | &mut self, | |
1732 | span: Span, | |
1733 | e: &'hir hir::Expr<'hir>, | |
1734 | args: &'hir [hir::Expr<'hir>], | |
1735 | ) -> hir::Expr<'hir> { | |
f2b60f7d | 1736 | self.expr(span, hir::ExprKind::Call(e, args), AttrVec::new()) |
ba9703b0 XL |
1737 | } |
1738 | ||
416331ca XL |
1739 | fn expr_call( |
1740 | &mut self, | |
1741 | span: Span, | |
dfeec247 XL |
1742 | e: &'hir hir::Expr<'hir>, |
1743 | args: &'hir [hir::Expr<'hir>], | |
1744 | ) -> &'hir hir::Expr<'hir> { | |
ba9703b0 | 1745 | self.arena.alloc(self.expr_call_mut(span, e, args)) |
416331ca XL |
1746 | } |
1747 | ||
3dfed10e | 1748 | fn expr_call_lang_item_fn_mut( |
416331ca XL |
1749 | &mut self, |
1750 | span: Span, | |
3dfed10e | 1751 | lang_item: hir::LangItem, |
dfeec247 | 1752 | args: &'hir [hir::Expr<'hir>], |
a2a8927a | 1753 | hir_id: Option<hir::HirId>, |
ba9703b0 | 1754 | ) -> hir::Expr<'hir> { |
a2a8927a | 1755 | let path = |
f2b60f7d | 1756 | self.arena.alloc(self.expr_lang_item_path(span, lang_item, AttrVec::new(), hir_id)); |
ba9703b0 XL |
1757 | self.expr_call_mut(span, path, args) |
1758 | } | |
1759 | ||
3dfed10e | 1760 | fn expr_call_lang_item_fn( |
ba9703b0 XL |
1761 | &mut self, |
1762 | span: Span, | |
3dfed10e | 1763 | lang_item: hir::LangItem, |
ba9703b0 | 1764 | args: &'hir [hir::Expr<'hir>], |
a2a8927a | 1765 | hir_id: Option<hir::HirId>, |
ba9703b0 | 1766 | ) -> &'hir hir::Expr<'hir> { |
a2a8927a | 1767 | self.arena.alloc(self.expr_call_lang_item_fn_mut(span, lang_item, args, hir_id)) |
416331ca XL |
1768 | } |
1769 | ||
3dfed10e | 1770 | fn expr_lang_item_path( |
416331ca XL |
1771 | &mut self, |
1772 | span: Span, | |
3dfed10e | 1773 | lang_item: hir::LangItem, |
dfeec247 | 1774 | attrs: AttrVec, |
a2a8927a | 1775 | hir_id: Option<hir::HirId>, |
dfeec247 | 1776 | ) -> hir::Expr<'hir> { |
94222f64 XL |
1777 | self.expr( |
1778 | span, | |
a2a8927a | 1779 | hir::ExprKind::Path(hir::QPath::LangItem(lang_item, self.lower_span(span), hir_id)), |
94222f64 XL |
1780 | attrs, |
1781 | ) | |
416331ca XL |
1782 | } |
1783 | ||
dfeec247 XL |
1784 | pub(super) fn expr_ident( |
1785 | &mut self, | |
1786 | sp: Span, | |
1787 | ident: Ident, | |
1788 | binding: hir::HirId, | |
1789 | ) -> &'hir hir::Expr<'hir> { | |
1790 | self.arena.alloc(self.expr_ident_mut(sp, ident, binding)) | |
1791 | } | |
1792 | ||
1793 | pub(super) fn expr_ident_mut( | |
1794 | &mut self, | |
1795 | sp: Span, | |
1796 | ident: Ident, | |
1797 | binding: hir::HirId, | |
1798 | ) -> hir::Expr<'hir> { | |
f2b60f7d | 1799 | self.expr_ident_with_attrs(sp, ident, binding, AttrVec::new()) |
416331ca XL |
1800 | } |
1801 | ||
1802 | fn expr_ident_with_attrs( | |
1803 | &mut self, | |
1804 | span: Span, | |
1805 | ident: Ident, | |
1806 | binding: hir::HirId, | |
dfeec247 XL |
1807 | attrs: AttrVec, |
1808 | ) -> hir::Expr<'hir> { | |
f2b60f7d FG |
1809 | let hir_id = self.next_id(); |
1810 | let res = Res::Local(binding); | |
416331ca XL |
1811 | let expr_path = hir::ExprKind::Path(hir::QPath::Resolved( |
1812 | None, | |
dfeec247 | 1813 | self.arena.alloc(hir::Path { |
94222f64 | 1814 | span: self.lower_span(span), |
f2b60f7d FG |
1815 | res, |
1816 | segments: arena_vec![self; hir::PathSegment::new(ident, hir_id, res)], | |
416331ca XL |
1817 | }), |
1818 | )); | |
1819 | ||
1820 | self.expr(span, expr_path, attrs) | |
1821 | } | |
1822 | ||
dfeec247 | 1823 | fn expr_unsafe(&mut self, expr: &'hir hir::Expr<'hir>) -> hir::Expr<'hir> { |
416331ca XL |
1824 | let hir_id = self.next_id(); |
1825 | let span = expr.span; | |
1826 | self.expr( | |
1827 | span, | |
dfeec247 XL |
1828 | hir::ExprKind::Block( |
1829 | self.arena.alloc(hir::Block { | |
1830 | stmts: &[], | |
1831 | expr: Some(expr), | |
1832 | hir_id, | |
1833 | rules: hir::BlockCheckMode::UnsafeBlock(hir::UnsafeSource::CompilerGenerated), | |
94222f64 | 1834 | span: self.lower_span(span), |
dfeec247 XL |
1835 | targeted_by_break: false, |
1836 | }), | |
1837 | None, | |
1838 | ), | |
f2b60f7d | 1839 | AttrVec::new(), |
416331ca XL |
1840 | ) |
1841 | } | |
1842 | ||
dfeec247 XL |
1843 | fn expr_block_empty(&mut self, span: Span) -> &'hir hir::Expr<'hir> { |
1844 | let blk = self.block_all(span, &[], None); | |
f2b60f7d | 1845 | let expr = self.expr_block(blk, AttrVec::new()); |
dfeec247 | 1846 | self.arena.alloc(expr) |
416331ca XL |
1847 | } |
1848 | ||
dfeec247 XL |
1849 | pub(super) fn expr_block( |
1850 | &mut self, | |
1851 | b: &'hir hir::Block<'hir>, | |
1852 | attrs: AttrVec, | |
1853 | ) -> hir::Expr<'hir> { | |
416331ca XL |
1854 | self.expr(b.span, hir::ExprKind::Block(b, None), attrs) |
1855 | } | |
1856 | ||
1857 | pub(super) fn expr( | |
1858 | &mut self, | |
1859 | span: Span, | |
dfeec247 XL |
1860 | kind: hir::ExprKind<'hir>, |
1861 | attrs: AttrVec, | |
1862 | ) -> hir::Expr<'hir> { | |
6a06907d XL |
1863 | let hir_id = self.next_id(); |
1864 | self.lower_attrs(hir_id, &attrs); | |
94222f64 | 1865 | hir::Expr { hir_id, kind, span: self.lower_span(span) } |
416331ca XL |
1866 | } |
1867 | ||
6a06907d XL |
1868 | fn expr_field( |
1869 | &mut self, | |
1870 | ident: Ident, | |
1871 | expr: &'hir hir::Expr<'hir>, | |
1872 | span: Span, | |
1873 | ) -> hir::ExprField<'hir> { | |
94222f64 XL |
1874 | hir::ExprField { |
1875 | hir_id: self.next_id(), | |
1876 | ident, | |
1877 | span: self.lower_span(span), | |
1878 | expr, | |
1879 | is_shorthand: false, | |
1880 | } | |
416331ca XL |
1881 | } |
1882 | ||
dfeec247 | 1883 | fn arm(&mut self, pat: &'hir hir::Pat<'hir>, expr: &'hir hir::Expr<'hir>) -> hir::Arm<'hir> { |
94222f64 XL |
1884 | hir::Arm { |
1885 | hir_id: self.next_id(), | |
1886 | pat, | |
1887 | guard: None, | |
1888 | span: self.lower_span(expr.span), | |
1889 | body: expr, | |
1890 | } | |
416331ca XL |
1891 | } |
1892 | } |