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Commit | Line | Data |
---|---|---|
9fa01778 | 1 | use crate::build; |
dc9dc135 | 2 | use crate::build::scope::DropKind; |
3dfed10e XL |
3 | use crate::thir::cx::Cx; |
4 | use crate::thir::{BindingMode, LintLevel, PatKind}; | |
74b04a01 | 5 | use rustc_attr::{self as attr, UnwindAttr}; |
ba9703b0 | 6 | use rustc_errors::ErrorReported; |
dfeec247 | 7 | use rustc_hir as hir; |
f9f354fc | 8 | use rustc_hir::def_id::{DefId, LocalDefId}; |
3dfed10e | 9 | use rustc_hir::lang_items::LangItem; |
dfeec247 XL |
10 | use rustc_hir::{GeneratorKind, HirIdMap, Node}; |
11 | use rustc_index::vec::{Idx, IndexVec}; | |
74b04a01 | 12 | use rustc_infer::infer::TyCtxtInferExt; |
ba9703b0 XL |
13 | use rustc_middle::middle::region; |
14 | use rustc_middle::mir::*; | |
15 | use rustc_middle::ty::subst::Subst; | |
16 | use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable}; | |
dfeec247 XL |
17 | use rustc_span::symbol::kw; |
18 | use rustc_span::Span; | |
19 | use rustc_target::spec::abi::Abi; | |
83c7162d | 20 | use rustc_target::spec::PanicStrategy; |
3157f602 | 21 | |
0bf4aa26 XL |
22 | use super::lints; |
23 | ||
3dfed10e XL |
24 | crate fn mir_built<'tcx>( |
25 | tcx: TyCtxt<'tcx>, | |
26 | def: ty::WithOptConstParam<LocalDefId>, | |
27 | ) -> &'tcx ty::steal::Steal<Body<'tcx>> { | |
28 | if let Some(def) = def.try_upgrade(tcx) { | |
29 | return tcx.mir_built(def); | |
30 | } | |
31 | ||
32 | tcx.alloc_steal_mir(mir_build(tcx, def)) | |
dfeec247 XL |
33 | } |
34 | ||
9fa01778 | 35 | /// Construct the MIR for a given `DefId`. |
3dfed10e XL |
36 | fn mir_build(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> Body<'_> { |
37 | let id = tcx.hir().local_def_id_to_hir_id(def.did); | |
3157f602 | 38 | |
7cac9316 | 39 | // Figure out what primary body this item has. |
3dfed10e | 40 | let (body_id, return_ty_span, span_with_body) = match tcx.hir().get(id) { |
dfeec247 | 41 | Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(_, decl, body_id, _, _), .. }) => { |
3dfed10e | 42 | (*body_id, decl.output.span(), None) |
0bf4aa26 | 43 | } |
dfeec247 XL |
44 | Node::Item(hir::Item { |
45 | kind: hir::ItemKind::Fn(hir::FnSig { decl, .. }, _, body_id), | |
3dfed10e | 46 | span, |
dfeec247 XL |
47 | .. |
48 | }) | |
49 | | Node::ImplItem(hir::ImplItem { | |
ba9703b0 | 50 | kind: hir::ImplItemKind::Fn(hir::FnSig { decl, .. }, body_id), |
3dfed10e | 51 | span, |
dfeec247 XL |
52 | .. |
53 | }) | |
54 | | Node::TraitItem(hir::TraitItem { | |
ba9703b0 | 55 | kind: hir::TraitItemKind::Fn(hir::FnSig { decl, .. }, hir::TraitFn::Provided(body_id)), |
3dfed10e | 56 | span, |
dfeec247 | 57 | .. |
3dfed10e XL |
58 | }) => { |
59 | // Use the `Span` of the `Item/ImplItem/TraitItem` as the body span, | |
60 | // since the def span of a function does not include the body | |
61 | (*body_id, decl.output.span(), Some(*span)) | |
62 | } | |
ba9703b0 XL |
63 | Node::Item(hir::Item { |
64 | kind: hir::ItemKind::Static(ty, _, body_id) | hir::ItemKind::Const(ty, body_id), | |
65 | .. | |
66 | }) | |
e74abb32 | 67 | | Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(ty, body_id), .. }) |
dfeec247 XL |
68 | | Node::TraitItem(hir::TraitItem { |
69 | kind: hir::TraitItemKind::Const(ty, Some(body_id)), | |
70 | .. | |
3dfed10e XL |
71 | }) => (*body_id, ty.span, None), |
72 | Node::AnonConst(hir::AnonConst { body, hir_id, .. }) => (*body, tcx.hir().span(*hir_id), None), | |
0bf4aa26 | 73 | |
3dfed10e | 74 | _ => span_bug!(tcx.hir().span(id), "can't build MIR for {:?}", def.did), |
7cac9316 XL |
75 | }; |
76 | ||
3dfed10e XL |
77 | // If we don't have a specialized span for the body, just use the |
78 | // normal def span. | |
79 | let span_with_body = span_with_body.unwrap_or_else(|| tcx.hir().span(id)); | |
80 | ||
041b39d2 | 81 | tcx.infer_ctxt().enter(|infcx| { |
3dfed10e XL |
82 | let cx = Cx::new(&infcx, def, id); |
83 | let body = if let Some(ErrorReported) = cx.typeck_results().tainted_by_errors { | |
7cac9316 | 84 | build::construct_error(cx, body_id) |
9fa01778 | 85 | } else if cx.body_owner_kind.is_fn_or_closure() { |
7cac9316 XL |
86 | // fetch the fully liberated fn signature (that is, all bound |
87 | // types/lifetimes replaced) | |
3dfed10e | 88 | let fn_sig = cx.typeck_results().liberated_fn_sigs()[id]; |
416331ca | 89 | let fn_def_id = tcx.hir().local_def_id(id); |
7cac9316 | 90 | |
74b04a01 XL |
91 | let safety = match fn_sig.unsafety { |
92 | hir::Unsafety::Normal => Safety::Safe, | |
93 | hir::Unsafety::Unsafe => Safety::FnUnsafe, | |
94 | }; | |
95 | ||
96 | let body = tcx.hir().body(body_id); | |
0731742a | 97 | let ty = tcx.type_of(fn_def_id); |
7cac9316 | 98 | let mut abi = fn_sig.abi; |
e74abb32 | 99 | let implicit_argument = match ty.kind { |
b7449926 | 100 | ty::Closure(..) => { |
ea8adc8c XL |
101 | // HACK(eddyb) Avoid having RustCall on closures, |
102 | // as it adds unnecessary (and wrong) auto-tupling. | |
103 | abi = Abi::Rust; | |
74b04a01 | 104 | vec![ArgInfo(liberated_closure_env_ty(tcx, id, body_id), None, None, None)] |
ea8adc8c | 105 | } |
b7449926 | 106 | ty::Generator(..) => { |
3dfed10e | 107 | let gen_ty = tcx.typeck_body(body_id).node_type(id); |
ea8adc8c | 108 | |
74b04a01 XL |
109 | // The resume argument may be missing, in that case we need to provide it here. |
110 | // It will always be `()` in this case. | |
111 | if body.params.is_empty() { | |
112 | vec![ | |
113 | ArgInfo(gen_ty, None, None, None), | |
114 | ArgInfo(tcx.mk_unit(), None, None, None), | |
115 | ] | |
116 | } else { | |
117 | vec![ArgInfo(gen_ty, None, None, None)] | |
118 | } | |
119 | } | |
120 | _ => vec![], | |
7cac9316 XL |
121 | }; |
122 | ||
dfeec247 XL |
123 | let explicit_arguments = body.params.iter().enumerate().map(|(index, arg)| { |
124 | let owner_id = tcx.hir().body_owner(body_id); | |
125 | let opt_ty_info; | |
126 | let self_arg; | |
127 | if let Some(ref fn_decl) = tcx.hir().fn_decl_by_hir_id(owner_id) { | |
128 | opt_ty_info = fn_decl.inputs.get(index).map(|ty| ty.span); | |
129 | self_arg = if index == 0 && fn_decl.implicit_self.has_implicit_self() { | |
130 | match fn_decl.implicit_self { | |
131 | hir::ImplicitSelfKind::Imm => Some(ImplicitSelfKind::Imm), | |
132 | hir::ImplicitSelfKind::Mut => Some(ImplicitSelfKind::Mut), | |
133 | hir::ImplicitSelfKind::ImmRef => Some(ImplicitSelfKind::ImmRef), | |
134 | hir::ImplicitSelfKind::MutRef => Some(ImplicitSelfKind::MutRef), | |
135 | _ => None, | |
94b46f34 | 136 | } |
dfeec247 XL |
137 | } else { |
138 | None | |
139 | }; | |
140 | } else { | |
141 | opt_ty_info = None; | |
142 | self_arg = None; | |
143 | } | |
dc9dc135 | 144 | |
dfeec247 XL |
145 | // C-variadic fns also have a `VaList` input that's not listed in `fn_sig` |
146 | // (as it's created inside the body itself, not passed in from outside). | |
147 | let ty = if fn_sig.c_variadic && index == fn_sig.inputs().len() { | |
3dfed10e | 148 | let va_list_did = tcx.require_lang_item(LangItem::VaList, Some(arg.span)); |
dfeec247 | 149 | |
ba9703b0 | 150 | tcx.type_of(va_list_did).subst(tcx, &[tcx.lifetimes.re_erased.into()]) |
dfeec247 XL |
151 | } else { |
152 | fn_sig.inputs()[index] | |
153 | }; | |
e74abb32 | 154 | |
dfeec247 XL |
155 | ArgInfo(ty, opt_ty_info, Some(&arg), self_arg) |
156 | }); | |
7cac9316 XL |
157 | |
158 | let arguments = implicit_argument.into_iter().chain(explicit_arguments); | |
ea8adc8c | 159 | |
dc9dc135 | 160 | let (yield_ty, return_ty) = if body.generator_kind.is_some() { |
3dfed10e | 161 | let gen_ty = tcx.typeck_body(body_id).node_type(id); |
ba9703b0 XL |
162 | let gen_sig = match gen_ty.kind { |
163 | ty::Generator(_, gen_substs, ..) => gen_substs.as_generator().sig(), | |
dfeec247 | 164 | _ => span_bug!(tcx.hir().span(id), "generator w/o generator type: {:?}", ty), |
ff7c6d11 | 165 | }; |
ea8adc8c XL |
166 | (Some(gen_sig.yield_ty), gen_sig.return_ty) |
167 | } else { | |
168 | (None, fn_sig.output()) | |
169 | }; | |
170 | ||
60c5eb7d XL |
171 | let mut mir = build::construct_fn( |
172 | cx, | |
173 | id, | |
174 | arguments, | |
175 | safety, | |
176 | abi, | |
177 | return_ty, | |
178 | return_ty_span, | |
179 | body, | |
3dfed10e | 180 | span_with_body |
60c5eb7d XL |
181 | ); |
182 | mir.yield_ty = yield_ty; | |
183 | mir | |
7cac9316 | 184 | } else { |
48663c56 XL |
185 | // Get the revealed type of this const. This is *not* the adjusted |
186 | // type of its body, which may be a subtype of this type. For | |
187 | // example: | |
188 | // | |
189 | // fn foo(_: &()) {} | |
190 | // static X: fn(&'static ()) = foo; | |
191 | // | |
192 | // The adjusted type of the body of X is `for<'a> fn(&'a ())` which | |
193 | // is not the same as the type of X. We need the type of the return | |
194 | // place to be the type of the constant because NLL typeck will | |
195 | // equate them. | |
196 | ||
3dfed10e | 197 | let return_ty = cx.typeck_results().node_type(id); |
48663c56 XL |
198 | |
199 | build::construct_const(cx, body_id, return_ty, return_ty_span) | |
7cac9316 XL |
200 | }; |
201 | ||
3dfed10e | 202 | lints::check(tcx, &body, def.did); |
0bf4aa26 | 203 | |
ba9703b0 XL |
204 | // The borrow checker will replace all the regions here with its own |
205 | // inference variables. There's no point having non-erased regions here. | |
206 | // The exception is `body.user_type_annotations`, which is used unmodified | |
207 | // by borrow checking. | |
208 | debug_assert!( | |
209 | !(body.local_decls.has_free_regions() | |
210 | || body.basic_blocks().has_free_regions() | |
211 | || body.var_debug_info.has_free_regions() | |
212 | || body.yield_ty.has_free_regions()), | |
213 | "Unexpected free regions in MIR: {:?}", | |
214 | body, | |
215 | ); | |
216 | ||
dc9dc135 | 217 | body |
7cac9316 XL |
218 | }) |
219 | } | |
220 | ||
7cac9316 XL |
221 | /////////////////////////////////////////////////////////////////////////// |
222 | // BuildMir -- walks a crate, looking for fn items and methods to build MIR from | |
223 | ||
416331ca XL |
224 | fn liberated_closure_env_ty( |
225 | tcx: TyCtxt<'_>, | |
dc9dc135 XL |
226 | closure_expr_id: hir::HirId, |
227 | body_id: hir::BodyId, | |
416331ca | 228 | ) -> Ty<'_> { |
3dfed10e | 229 | let closure_ty = tcx.typeck_body(body_id).node_type(closure_expr_id); |
7cac9316 | 230 | |
e74abb32 | 231 | let (closure_def_id, closure_substs) = match closure_ty.kind { |
b7449926 | 232 | ty::Closure(closure_def_id, closure_substs) => (closure_def_id, closure_substs), |
dfeec247 | 233 | _ => bug!("closure expr does not have closure type: {:?}", closure_ty), |
ff7c6d11 XL |
234 | }; |
235 | ||
236 | let closure_env_ty = tcx.closure_env_ty(closure_def_id, closure_substs).unwrap(); | |
ba9703b0 | 237 | tcx.erase_late_bound_regions(&closure_env_ty) |
7cac9316 | 238 | } |
b039eaaf | 239 | |
0bf4aa26 | 240 | #[derive(Debug, PartialEq, Eq)] |
dfeec247 | 241 | enum BlockFrame { |
0bf4aa26 XL |
242 | /// Evaluation is currently within a statement. |
243 | /// | |
244 | /// Examples include: | |
dc9dc135 XL |
245 | /// 1. `EXPR;` |
246 | /// 2. `let _ = EXPR;` | |
247 | /// 3. `let x = EXPR;` | |
0bf4aa26 XL |
248 | Statement { |
249 | /// If true, then statement discards result from evaluating | |
250 | /// the expression (such as examples 1 and 2 above). | |
dfeec247 | 251 | ignores_expr_result: bool, |
0bf4aa26 XL |
252 | }, |
253 | ||
254 | /// Evaluation is currently within the tail expression of a block. | |
255 | /// | |
256 | /// Example: `{ STMT_1; STMT_2; EXPR }` | |
257 | TailExpr { | |
258 | /// If true, then the surrounding context of the block ignores | |
259 | /// the result of evaluating the block's tail expression. | |
260 | /// | |
261 | /// Example: `let _ = { STMT_1; EXPR };` | |
dfeec247 | 262 | tail_result_is_ignored: bool, |
f9f354fc XL |
263 | |
264 | /// `Span` of the tail expression. | |
265 | span: Span, | |
0bf4aa26 XL |
266 | }, |
267 | ||
268 | /// Generic mark meaning that the block occurred as a subexpression | |
269 | /// where the result might be used. | |
270 | /// | |
271 | /// Examples: `foo(EXPR)`, `match EXPR { ... }` | |
272 | SubExpr, | |
273 | } | |
274 | ||
275 | impl BlockFrame { | |
276 | fn is_tail_expr(&self) -> bool { | |
277 | match *self { | |
278 | BlockFrame::TailExpr { .. } => true, | |
279 | ||
dfeec247 | 280 | BlockFrame::Statement { .. } | BlockFrame::SubExpr => false, |
0bf4aa26 XL |
281 | } |
282 | } | |
283 | fn is_statement(&self) -> bool { | |
284 | match *self { | |
285 | BlockFrame::Statement { .. } => true, | |
286 | ||
dfeec247 | 287 | BlockFrame::TailExpr { .. } | BlockFrame::SubExpr => false, |
0bf4aa26 XL |
288 | } |
289 | } | |
dfeec247 | 290 | } |
0bf4aa26 | 291 | |
a1dfa0c6 XL |
292 | #[derive(Debug)] |
293 | struct BlockContext(Vec<BlockFrame>); | |
294 | ||
dc9dc135 XL |
295 | struct Builder<'a, 'tcx> { |
296 | hir: Cx<'a, 'tcx>, | |
b039eaaf | 297 | cfg: CFG<'tcx>, |
54a0048b SL |
298 | |
299 | fn_span: Span, | |
c30ab7b3 | 300 | arg_count: usize, |
60c5eb7d | 301 | generator_kind: Option<GeneratorKind>, |
54a0048b | 302 | |
9fa01778 XL |
303 | /// The current set of scopes, updated as we traverse; |
304 | /// see the `scope` module for more details. | |
dc9dc135 | 305 | scopes: scope::Scopes<'tcx>, |
54a0048b | 306 | |
3dfed10e | 307 | /// The block-context: each time we build the code within an thir::Block, |
0bf4aa26 XL |
308 | /// we push a frame here tracking whether we are building a statement or |
309 | /// if we are pushing the tail expression of the block. This is used to | |
310 | /// embed information in generated temps about whether they were created | |
311 | /// for a block tail expression or not. | |
312 | /// | |
313 | /// It would be great if we could fold this into `self.scopes` | |
9fa01778 | 314 | /// somehow, but right now I think that is very tightly tied to |
0bf4aa26 XL |
315 | /// the code generation in ways that we cannot (or should not) |
316 | /// start just throwing new entries onto that vector in order to | |
317 | /// distinguish the context of EXPR1 from the context of EXPR2 in | |
9fa01778 | 318 | /// `{ STMTS; EXPR1 } + EXPR2`. |
a1dfa0c6 | 319 | block_context: BlockContext, |
0bf4aa26 | 320 | |
ea8adc8c | 321 | /// The current unsafe block in scope, even if it is hidden by |
9fa01778 | 322 | /// a `PushUnsafeBlock`. |
ea8adc8c XL |
323 | unpushed_unsafe: Safety, |
324 | ||
9fa01778 | 325 | /// The number of `push_unsafe_block` levels in scope. |
ea8adc8c XL |
326 | push_unsafe_count: usize, |
327 | ||
9fa01778 XL |
328 | /// The vector of all scopes that we have created thus far; |
329 | /// we track this for debuginfo later. | |
94b46f34 | 330 | source_scopes: IndexVec<SourceScope, SourceScopeData>, |
94b46f34 | 331 | source_scope: SourceScope, |
54a0048b | 332 | |
9fa01778 | 333 | /// The guard-context: each time we build the guard expression for |
83c7162d XL |
334 | /// a match arm, we push onto this stack, and then pop when we |
335 | /// finish building it. | |
336 | guard_context: Vec<GuardFrame>, | |
337 | ||
532ac7d7 | 338 | /// Maps `HirId`s of variable bindings to the `Local`s created for them. |
83c7162d | 339 | /// (A match binding can have two locals; the 2nd is for the arm's guard.) |
532ac7d7 | 340 | var_indices: HirIdMap<LocalsForNode>, |
c30ab7b3 | 341 | local_decls: IndexVec<Local, LocalDecl<'tcx>>, |
0731742a | 342 | canonical_user_type_annotations: ty::CanonicalUserTypeAnnotations<'tcx>, |
48663c56 | 343 | upvar_mutbls: Vec<Mutability>, |
ff7c6d11 | 344 | unit_temp: Option<Place<'tcx>>, |
54a0048b | 345 | |
60c5eb7d XL |
346 | var_debug_info: Vec<VarDebugInfo<'tcx>>, |
347 | ||
9fa01778 | 348 | /// Cached block with the `RESUME` terminator; this is created |
a7813a04 | 349 | /// when first set of cleanups are built. |
54a0048b | 350 | cached_resume_block: Option<BasicBlock>, |
9fa01778 | 351 | /// Cached block with the `RETURN` terminator. |
a7813a04 | 352 | cached_return_block: Option<BasicBlock>, |
9fa01778 | 353 | /// Cached block with the `UNREACHABLE` terminator. |
abe05a73 | 354 | cached_unreachable_block: Option<BasicBlock>, |
e9174d1e SL |
355 | } |
356 | ||
dc9dc135 | 357 | impl<'a, 'tcx> Builder<'a, 'tcx> { |
532ac7d7 | 358 | fn is_bound_var_in_guard(&self, id: hir::HirId) -> bool { |
83c7162d XL |
359 | self.guard_context.iter().any(|frame| frame.locals.iter().any(|local| local.id == id)) |
360 | } | |
361 | ||
532ac7d7 | 362 | fn var_local_id(&self, id: hir::HirId, for_guard: ForGuard) -> Local { |
83c7162d XL |
363 | self.var_indices[&id].local_id(for_guard) |
364 | } | |
365 | } | |
366 | ||
a1dfa0c6 | 367 | impl BlockContext { |
dfeec247 XL |
368 | fn new() -> Self { |
369 | BlockContext(vec![]) | |
370 | } | |
371 | fn push(&mut self, bf: BlockFrame) { | |
372 | self.0.push(bf); | |
373 | } | |
374 | fn pop(&mut self) -> Option<BlockFrame> { | |
375 | self.0.pop() | |
376 | } | |
a1dfa0c6 | 377 | |
9fa01778 | 378 | /// Traverses the frames on the `BlockContext`, searching for either |
a1dfa0c6 XL |
379 | /// the first block-tail expression frame with no intervening |
380 | /// statement frame. | |
381 | /// | |
382 | /// Notably, this skips over `SubExpr` frames; this method is | |
383 | /// meant to be used in the context of understanding the | |
384 | /// relationship of a temp (created within some complicated | |
385 | /// expression) with its containing expression, and whether the | |
386 | /// value of that *containing expression* (not the temp!) is | |
387 | /// ignored. | |
388 | fn currently_in_block_tail(&self) -> Option<BlockTailInfo> { | |
389 | for bf in self.0.iter().rev() { | |
390 | match bf { | |
391 | BlockFrame::SubExpr => continue, | |
392 | BlockFrame::Statement { .. } => break, | |
f9f354fc XL |
393 | &BlockFrame::TailExpr { tail_result_is_ignored, span } => { |
394 | return Some(BlockTailInfo { tail_result_is_ignored, span }); | |
dfeec247 | 395 | } |
a1dfa0c6 XL |
396 | } |
397 | } | |
398 | ||
ba9703b0 | 399 | None |
a1dfa0c6 XL |
400 | } |
401 | ||
402 | /// Looks at the topmost frame on the BlockContext and reports | |
403 | /// whether its one that would discard a block tail result. | |
404 | /// | |
405 | /// Unlike `currently_within_ignored_tail_expression`, this does | |
406 | /// *not* skip over `SubExpr` frames: here, we want to know | |
407 | /// whether the block result itself is discarded. | |
408 | fn currently_ignores_tail_results(&self) -> bool { | |
409 | match self.0.last() { | |
410 | // no context: conservatively assume result is read | |
411 | None => false, | |
412 | ||
413 | // sub-expression: block result feeds into some computation | |
414 | Some(BlockFrame::SubExpr) => false, | |
415 | ||
416 | // otherwise: use accumulated is_ignored state. | |
ba9703b0 | 417 | Some( |
f9f354fc | 418 | BlockFrame::TailExpr { tail_result_is_ignored: ignored, .. } |
ba9703b0 XL |
419 | | BlockFrame::Statement { ignores_expr_result: ignored }, |
420 | ) => *ignored, | |
a1dfa0c6 XL |
421 | } |
422 | } | |
423 | } | |
424 | ||
83c7162d XL |
425 | #[derive(Debug)] |
426 | enum LocalsForNode { | |
532ac7d7 | 427 | /// In the usual case, a `HirId` for an identifier maps to at most |
9fa01778 | 428 | /// one `Local` declaration. |
83c7162d | 429 | One(Local), |
8faf50e0 XL |
430 | |
431 | /// The exceptional case is identifiers in a match arm's pattern | |
432 | /// that are referenced in a guard of that match arm. For these, | |
9fa01778 | 433 | /// we have `2` Locals. |
8faf50e0 XL |
434 | /// |
435 | /// * `for_arm_body` is the Local used in the arm body (which is | |
436 | /// just like the `One` case above), | |
437 | /// | |
438 | /// * `ref_for_guard` is the Local used in the arm's guard (which | |
439 | /// is a reference to a temp that is an alias of | |
440 | /// `for_arm_body`). | |
9fa01778 | 441 | ForGuard { ref_for_guard: Local, for_arm_body: Local }, |
83c7162d XL |
442 | } |
443 | ||
444 | #[derive(Debug)] | |
445 | struct GuardFrameLocal { | |
532ac7d7 | 446 | id: hir::HirId, |
83c7162d XL |
447 | } |
448 | ||
449 | impl GuardFrameLocal { | |
532ac7d7 | 450 | fn new(id: hir::HirId, _binding_mode: BindingMode) -> Self { |
74b04a01 | 451 | GuardFrameLocal { id } |
83c7162d XL |
452 | } |
453 | } | |
454 | ||
455 | #[derive(Debug)] | |
456 | struct GuardFrame { | |
457 | /// These are the id's of names that are bound by patterns of the | |
458 | /// arm of *this* guard. | |
459 | /// | |
460 | /// (Frames higher up the stack will have the id's bound in arms | |
461 | /// further out, such as in a case like: | |
462 | /// | |
463 | /// match E1 { | |
464 | /// P1(id1) if (... (match E2 { P2(id2) if ... => B2 })) => B1, | |
465 | /// } | |
466 | /// | |
9fa01778 | 467 | /// here, when building for FIXME. |
83c7162d XL |
468 | locals: Vec<GuardFrameLocal>, |
469 | } | |
470 | ||
9fa01778 XL |
471 | /// `ForGuard` indicates whether we are talking about: |
472 | /// 1. The variable for use outside of guard expressions, or | |
473 | /// 2. The temp that holds reference to (1.), which is actually what the | |
474 | /// guard expressions see. | |
83c7162d XL |
475 | #[derive(Copy, Clone, Debug, PartialEq, Eq)] |
476 | enum ForGuard { | |
94b46f34 | 477 | RefWithinGuard, |
83c7162d XL |
478 | OutsideGuard, |
479 | } | |
480 | ||
481 | impl LocalsForNode { | |
482 | fn local_id(&self, for_guard: ForGuard) -> Local { | |
483 | match (self, for_guard) { | |
dfeec247 XL |
484 | (&LocalsForNode::One(local_id), ForGuard::OutsideGuard) |
485 | | ( | |
486 | &LocalsForNode::ForGuard { ref_for_guard: local_id, .. }, | |
487 | ForGuard::RefWithinGuard, | |
488 | ) | |
489 | | (&LocalsForNode::ForGuard { for_arm_body: local_id, .. }, ForGuard::OutsideGuard) => { | |
490 | local_id | |
491 | } | |
83c7162d | 492 | |
dfeec247 XL |
493 | (&LocalsForNode::One(_), ForGuard::RefWithinGuard) => { |
494 | bug!("anything with one local should never be within a guard.") | |
495 | } | |
83c7162d XL |
496 | } |
497 | } | |
498 | } | |
499 | ||
b039eaaf | 500 | struct CFG<'tcx> { |
3157f602 XL |
501 | basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>, |
502 | } | |
503 | ||
e74abb32 | 504 | rustc_index::newtype_index! { |
dfeec247 | 505 | struct ScopeId { .. } |
b7449926 | 506 | } |
e9174d1e SL |
507 | |
508 | /////////////////////////////////////////////////////////////////////////// | |
7453a54e SL |
509 | /// The `BlockAnd` "monad" packages up the new basic block along with a |
510 | /// produced value (sometimes just unit, of course). The `unpack!` | |
511 | /// macro (and methods below) makes working with `BlockAnd` much more | |
512 | /// convenient. | |
e9174d1e | 513 | |
83c7162d | 514 | #[must_use = "if you don't use one of these results, you're leaving a dangling edge"] |
7cac9316 | 515 | struct BlockAnd<T>(BasicBlock, T); |
e9174d1e | 516 | |
92a42be0 SL |
517 | trait BlockAndExtension { |
518 | fn and<T>(self, v: T) -> BlockAnd<T>; | |
519 | fn unit(self) -> BlockAnd<()>; | |
520 | } | |
521 | ||
522 | impl BlockAndExtension for BasicBlock { | |
e9174d1e SL |
523 | fn and<T>(self, v: T) -> BlockAnd<T> { |
524 | BlockAnd(self, v) | |
525 | } | |
526 | ||
527 | fn unit(self) -> BlockAnd<()> { | |
528 | BlockAnd(self, ()) | |
529 | } | |
530 | } | |
531 | ||
532 | /// Update a block pointer and return the value. | |
533 | /// Use it like `let x = unpack!(block = self.foo(block, foo))`. | |
534 | macro_rules! unpack { | |
dfeec247 XL |
535 | ($x:ident = $c:expr) => {{ |
536 | let BlockAnd(b, v) = $c; | |
537 | $x = b; | |
538 | v | |
539 | }}; | |
540 | ||
541 | ($c:expr) => {{ | |
542 | let BlockAnd(b, ()) = $c; | |
543 | b | |
544 | }}; | |
e9174d1e SL |
545 | } |
546 | ||
f9f354fc | 547 | fn should_abort_on_panic(tcx: TyCtxt<'_>, fn_def_id: LocalDefId, _abi: Abi) -> bool { |
e74abb32 | 548 | // Validate `#[unwind]` syntax regardless of platform-specific panic strategy. |
f9f354fc | 549 | let attrs = &tcx.get_attrs(fn_def_id.to_def_id()); |
3dfed10e | 550 | let unwind_attr = attr::find_unwind_attr(&tcx.sess, attrs); |
532ac7d7 | 551 | |
e74abb32 | 552 | // We never unwind, so it's not relevant to stop an unwind. |
dfeec247 XL |
553 | if tcx.sess.panic_strategy() != PanicStrategy::Unwind { |
554 | return false; | |
555 | } | |
ff7c6d11 | 556 | |
ff7c6d11 XL |
557 | // This is a special case: some functions have a C abi but are meant to |
558 | // unwind anyway. Don't stop them. | |
532ac7d7 | 559 | match unwind_attr { |
e74abb32 | 560 | None => false, // FIXME(#58794); should be `!(abi == Abi::Rust || abi == Abi::RustCall)` |
0531ce1d XL |
561 | Some(UnwindAttr::Allowed) => false, |
562 | Some(UnwindAttr::Aborts) => true, | |
563 | } | |
ff7c6d11 XL |
564 | } |
565 | ||
e9174d1e | 566 | /////////////////////////////////////////////////////////////////////////// |
7453a54e | 567 | /// the main entry point for building MIR for a function |
e9174d1e | 568 | |
dfeec247 XL |
569 | struct ArgInfo<'tcx>( |
570 | Ty<'tcx>, | |
571 | Option<Span>, | |
572 | Option<&'tcx hir::Param<'tcx>>, | |
573 | Option<ImplicitSelfKind>, | |
574 | ); | |
dc9dc135 XL |
575 | |
576 | fn construct_fn<'a, 'tcx, A>( | |
577 | hir: Cx<'a, 'tcx>, | |
578 | fn_id: hir::HirId, | |
579 | arguments: A, | |
580 | safety: Safety, | |
581 | abi: Abi, | |
582 | return_ty: Ty<'tcx>, | |
dc9dc135 | 583 | return_ty_span: Span, |
dfeec247 | 584 | body: &'tcx hir::Body<'tcx>, |
3dfed10e | 585 | span_with_body: Span |
dc9dc135 XL |
586 | ) -> Body<'tcx> |
587 | where | |
dfeec247 | 588 | A: Iterator<Item = ArgInfo<'tcx>>, |
a7813a04 | 589 | { |
c30ab7b3 SL |
590 | let arguments: Vec<_> = arguments.collect(); |
591 | ||
54a0048b | 592 | let tcx = hir.tcx(); |
0731742a | 593 | let tcx_hir = tcx.hir(); |
dc9dc135 | 594 | let span = tcx_hir.span(fn_id); |
0731742a | 595 | |
416331ca | 596 | let fn_def_id = tcx_hir.local_def_id(fn_id); |
8faf50e0 | 597 | |
dfeec247 XL |
598 | let mut builder = Builder::new( |
599 | hir, | |
3dfed10e | 600 | span_with_body, |
ea8adc8c XL |
601 | arguments.len(), |
602 | safety, | |
8faf50e0 | 603 | return_ty, |
0bf4aa26 | 604 | return_ty_span, |
dfeec247 XL |
605 | body.generator_kind, |
606 | ); | |
ea8adc8c | 607 | |
dfeec247 XL |
608 | let call_site_scope = |
609 | region::Scope { id: body.value.hir_id.local_id, data: region::ScopeData::CallSite }; | |
610 | let arg_scope = | |
611 | region::Scope { id: body.value.hir_id.local_id, data: region::ScopeData::Arguments }; | |
a7813a04 | 612 | let mut block = START_BLOCK; |
041b39d2 | 613 | let source_info = builder.source_info(span); |
ea8adc8c | 614 | let call_site_s = (call_site_scope, source_info); |
dfeec247 XL |
615 | unpack!( |
616 | block = builder.in_scope(call_site_s, LintLevel::Inherited, |builder| { | |
617 | if should_abort_on_panic(tcx, fn_def_id, abi) { | |
618 | builder.schedule_abort(); | |
619 | } | |
ff7c6d11 | 620 | |
dfeec247 XL |
621 | let arg_scope_s = (arg_scope, source_info); |
622 | // `return_block` is called when we evaluate a `return` expression, so | |
623 | // we just use `START_BLOCK` here. | |
624 | unpack!( | |
625 | block = builder.in_breakable_scope( | |
626 | None, | |
627 | START_BLOCK, | |
628 | Place::return_place(), | |
629 | |builder| { | |
630 | builder.in_scope(arg_scope_s, LintLevel::Inherited, |builder| { | |
631 | builder.args_and_body( | |
632 | block, | |
f9f354fc | 633 | fn_def_id.to_def_id(), |
dfeec247 XL |
634 | &arguments, |
635 | arg_scope, | |
636 | &body.value, | |
637 | ) | |
638 | }) | |
639 | }, | |
640 | ) | |
641 | ); | |
642 | // Attribute epilogue to function's closing brace | |
3dfed10e | 643 | let fn_end = span_with_body.shrink_to_hi(); |
dfeec247 XL |
644 | let source_info = builder.source_info(fn_end); |
645 | let return_block = builder.return_block(); | |
646 | builder.cfg.goto(block, source_info, return_block); | |
647 | builder.cfg.terminate(return_block, source_info, TerminatorKind::Return); | |
648 | // Attribute any unreachable codepaths to the function's closing brace | |
649 | if let Some(unreachable_block) = builder.cached_unreachable_block { | |
650 | builder.cfg.terminate(unreachable_block, source_info, TerminatorKind::Unreachable); | |
651 | } | |
652 | return_block.unit() | |
653 | }) | |
654 | ); | |
a7813a04 XL |
655 | assert_eq!(block, builder.return_block()); |
656 | ||
ba9703b0 | 657 | let spread_arg = if abi == Abi::RustCall { |
476ff2be | 658 | // RustCall pseudo-ABI untuples the last argument. |
ba9703b0 XL |
659 | Some(Local::new(arguments.len())) |
660 | } else { | |
661 | None | |
662 | }; | |
f9f354fc | 663 | debug!("fn_id {:?} has attrs {:?}", fn_def_id, tcx.get_attrs(fn_def_id.to_def_id())); |
54a0048b | 664 | |
60c5eb7d | 665 | let mut body = builder.finish(); |
dc9dc135 XL |
666 | body.spread_arg = spread_arg; |
667 | body | |
a7813a04 XL |
668 | } |
669 | ||
dc9dc135 XL |
670 | fn construct_const<'a, 'tcx>( |
671 | hir: Cx<'a, 'tcx>, | |
0bf4aa26 | 672 | body_id: hir::BodyId, |
48663c56 XL |
673 | const_ty: Ty<'tcx>, |
674 | const_ty_span: Span, | |
dc9dc135 | 675 | ) -> Body<'tcx> { |
a7813a04 | 676 | let tcx = hir.tcx(); |
0731742a XL |
677 | let owner_id = tcx.hir().body_owner(body_id); |
678 | let span = tcx.hir().span(owner_id); | |
dfeec247 | 679 | let mut builder = Builder::new(hir, span, 0, Safety::Safe, const_ty, const_ty_span, None); |
a7813a04 | 680 | |
a7813a04 | 681 | let mut block = START_BLOCK; |
48663c56 | 682 | let ast_expr = &tcx.hir().body(body_id).value; |
7cac9316 | 683 | let expr = builder.hir.mirror(ast_expr); |
ba9703b0 | 684 | unpack!(block = builder.into_expr(Place::return_place(), block, expr)); |
a7813a04 | 685 | |
7cac9316 XL |
686 | let source_info = builder.source_info(span); |
687 | builder.cfg.terminate(block, source_info, TerminatorKind::Return); | |
a7813a04 | 688 | |
7cac9316 XL |
689 | // Constants can't `return` so a return block should not be created. |
690 | assert_eq!(builder.cached_return_block, None); | |
a7813a04 | 691 | |
ff7c6d11 XL |
692 | // Constants may be match expressions in which case an unreachable block may |
693 | // be created, so terminate it properly. | |
694 | if let Some(unreachable_block) = builder.cached_unreachable_block { | |
dfeec247 | 695 | builder.cfg.terminate(unreachable_block, source_info, TerminatorKind::Unreachable); |
ff7c6d11 XL |
696 | } |
697 | ||
60c5eb7d | 698 | builder.finish() |
e9174d1e SL |
699 | } |
700 | ||
74b04a01 XL |
701 | /// Construct MIR for a item that has had errors in type checking. |
702 | /// | |
703 | /// This is required because we may still want to run MIR passes on an item | |
704 | /// with type errors, but normal MIR construction can't handle that in general. | |
dfeec247 | 705 | fn construct_error<'a, 'tcx>(hir: Cx<'a, 'tcx>, body_id: hir::BodyId) -> Body<'tcx> { |
74b04a01 XL |
706 | let tcx = hir.tcx(); |
707 | let owner_id = tcx.hir().body_owner(body_id); | |
708 | let span = tcx.hir().span(owner_id); | |
f035d41b | 709 | let ty = tcx.ty_error(); |
74b04a01 XL |
710 | let num_params = match hir.body_owner_kind { |
711 | hir::BodyOwnerKind::Fn => tcx.hir().fn_decl_by_hir_id(owner_id).unwrap().inputs.len(), | |
712 | hir::BodyOwnerKind::Closure => { | |
713 | if tcx.hir().body(body_id).generator_kind().is_some() { | |
714 | // Generators have an implicit `self` parameter *and* a possibly | |
715 | // implicit resume parameter. | |
716 | 2 | |
717 | } else { | |
718 | // The implicit self parameter adds another local in MIR. | |
719 | 1 + tcx.hir().fn_decl_by_hir_id(owner_id).unwrap().inputs.len() | |
720 | } | |
721 | } | |
722 | hir::BodyOwnerKind::Const => 0, | |
723 | hir::BodyOwnerKind::Static(_) => 0, | |
724 | }; | |
725 | let mut builder = Builder::new(hir, span, num_params, Safety::Safe, ty, span, None); | |
8bb4bdeb | 726 | let source_info = builder.source_info(span); |
74b04a01 XL |
727 | // Some MIR passes will expect the number of parameters to match the |
728 | // function declaration. | |
729 | for _ in 0..num_params { | |
f9f354fc | 730 | builder.local_decls.push(LocalDecl::with_source_info(ty, source_info)); |
74b04a01 | 731 | } |
8bb4bdeb | 732 | builder.cfg.terminate(START_BLOCK, source_info, TerminatorKind::Unreachable); |
74b04a01 XL |
733 | let mut body = builder.finish(); |
734 | if tcx.hir().body(body_id).generator_kind.is_some() { | |
735 | body.yield_ty = Some(ty); | |
736 | } | |
737 | body | |
8bb4bdeb XL |
738 | } |
739 | ||
dc9dc135 | 740 | impl<'a, 'tcx> Builder<'a, 'tcx> { |
dfeec247 XL |
741 | fn new( |
742 | hir: Cx<'a, 'tcx>, | |
743 | span: Span, | |
744 | arg_count: usize, | |
745 | safety: Safety, | |
746 | return_ty: Ty<'tcx>, | |
747 | return_span: Span, | |
748 | generator_kind: Option<GeneratorKind>, | |
749 | ) -> Builder<'a, 'tcx> { | |
ea8adc8c | 750 | let lint_level = LintLevel::Explicit(hir.root_lint_level); |
a7813a04 | 751 | let mut builder = Builder { |
3b2f2976 | 752 | hir, |
3157f602 | 753 | cfg: CFG { basic_blocks: IndexVec::new() }, |
a7813a04 | 754 | fn_span: span, |
3b2f2976 | 755 | arg_count, |
60c5eb7d | 756 | generator_kind, |
dc9dc135 | 757 | scopes: Default::default(), |
a1dfa0c6 | 758 | block_context: BlockContext::new(), |
94b46f34 XL |
759 | source_scopes: IndexVec::new(), |
760 | source_scope: OUTERMOST_SOURCE_SCOPE, | |
83c7162d | 761 | guard_context: vec![], |
ea8adc8c XL |
762 | push_unsafe_count: 0, |
763 | unpushed_unsafe: safety, | |
f9f354fc | 764 | local_decls: IndexVec::from_elem_n(LocalDecl::new(return_ty, return_span), 1), |
0731742a | 765 | canonical_user_type_annotations: IndexVec::new(), |
60c5eb7d | 766 | upvar_mutbls: vec![], |
a1dfa0c6 | 767 | var_indices: Default::default(), |
a7813a04 | 768 | unit_temp: None, |
60c5eb7d | 769 | var_debug_info: vec![], |
a7813a04 | 770 | cached_resume_block: None, |
abe05a73 XL |
771 | cached_return_block: None, |
772 | cached_unreachable_block: None, | |
a7813a04 XL |
773 | }; |
774 | ||
775 | assert_eq!(builder.cfg.start_new_block(), START_BLOCK); | |
ea8adc8c | 776 | assert_eq!( |
94b46f34 | 777 | builder.new_source_scope(span, lint_level, Some(safety)), |
dfeec247 XL |
778 | OUTERMOST_SOURCE_SCOPE |
779 | ); | |
94b46f34 | 780 | builder.source_scopes[OUTERMOST_SOURCE_SCOPE].parent_scope = None; |
a7813a04 XL |
781 | |
782 | builder | |
783 | } | |
784 | ||
60c5eb7d | 785 | fn finish(self) -> Body<'tcx> { |
a7813a04 XL |
786 | for (index, block) in self.cfg.basic_blocks.iter().enumerate() { |
787 | if block.terminator.is_none() { | |
788 | span_bug!(self.fn_span, "no terminator on block {:?}", index); | |
789 | } | |
790 | } | |
791 | ||
dc9dc135 | 792 | Body::new( |
0731742a XL |
793 | self.cfg.basic_blocks, |
794 | self.source_scopes, | |
0731742a XL |
795 | self.local_decls, |
796 | self.canonical_user_type_annotations, | |
797 | self.arg_count, | |
60c5eb7d | 798 | self.var_debug_info, |
0731742a | 799 | self.fn_span, |
dfeec247 | 800 | self.generator_kind, |
476ff2be | 801 | ) |
a7813a04 XL |
802 | } |
803 | ||
dfeec247 XL |
804 | fn args_and_body( |
805 | &mut self, | |
806 | mut block: BasicBlock, | |
807 | fn_def_id: DefId, | |
808 | arguments: &[ArgInfo<'tcx>], | |
809 | argument_scope: region::Scope, | |
810 | ast_body: &'tcx hir::Expr<'tcx>, | |
811 | ) -> BlockAnd<()> { | |
c30ab7b3 | 812 | // Allocate locals for the function arguments |
416331ca | 813 | for &ArgInfo(ty, _, arg_opt, _) in arguments.iter() { |
f9f354fc XL |
814 | let source_info = |
815 | SourceInfo::outermost(arg_opt.map_or(self.fn_span, |arg| arg.pat.span)); | |
816 | let arg_local = self.local_decls.push(LocalDecl::with_source_info(ty, source_info)); | |
60c5eb7d XL |
817 | |
818 | // If this is a simple binding pattern, give debuginfo a nice name. | |
819 | if let Some(arg) = arg_opt { | |
820 | if let Some(ident) = arg.pat.simple_ident() { | |
821 | self.var_debug_info.push(VarDebugInfo { | |
822 | name: ident.name, | |
823 | source_info, | |
824 | place: arg_local.into(), | |
825 | }); | |
826 | } | |
827 | } | |
828 | } | |
829 | ||
830 | let tcx = self.hir.tcx(); | |
831 | let tcx_hir = tcx.hir(); | |
3dfed10e | 832 | let hir_typeck_results = self.hir.typeck_results(); |
60c5eb7d XL |
833 | |
834 | // In analyze_closure() in upvar.rs we gathered a list of upvars used by a | |
3dfed10e | 835 | // indexed closure and we stored in a map called closure_captures in TypeckResults |
60c5eb7d XL |
836 | // with the closure's DefId. Here, we run through that vec of UpvarIds for |
837 | // the given closure and use the necessary information to create upvar | |
838 | // debuginfo and to fill `self.upvar_mutbls`. | |
3dfed10e | 839 | if let Some(upvars) = hir_typeck_results.closure_captures.get(&fn_def_id) { |
60c5eb7d XL |
840 | let closure_env_arg = Local::new(1); |
841 | let mut closure_env_projs = vec![]; | |
842 | let mut closure_ty = self.local_decls[closure_env_arg].ty; | |
843 | if let ty::Ref(_, ty, _) = closure_ty.kind { | |
844 | closure_env_projs.push(ProjectionElem::Deref); | |
845 | closure_ty = ty; | |
846 | } | |
ba9703b0 XL |
847 | let upvar_substs = match closure_ty.kind { |
848 | ty::Closure(_, substs) => ty::UpvarSubsts::Closure(substs), | |
849 | ty::Generator(_, substs, _) => ty::UpvarSubsts::Generator(substs), | |
dfeec247 | 850 | _ => span_bug!(self.fn_span, "upvars with non-closure env ty {:?}", closure_ty), |
60c5eb7d | 851 | }; |
ba9703b0 | 852 | let upvar_tys = upvar_substs.upvar_tys(); |
60c5eb7d | 853 | let upvars_with_tys = upvars.iter().zip(upvar_tys); |
dfeec247 XL |
854 | self.upvar_mutbls = upvars_with_tys |
855 | .enumerate() | |
856 | .map(|(i, ((&var_id, &upvar_id), ty))| { | |
3dfed10e | 857 | let capture = hir_typeck_results.upvar_capture(upvar_id); |
dfeec247 XL |
858 | |
859 | let mut mutability = Mutability::Not; | |
860 | let mut name = kw::Invalid; | |
861 | if let Some(Node::Binding(pat)) = tcx_hir.find(var_id) { | |
862 | if let hir::PatKind::Binding(_, _, ident, _) = pat.kind { | |
863 | name = ident.name; | |
3dfed10e XL |
864 | match hir_typeck_results |
865 | .extract_binding_mode(tcx.sess, pat.hir_id, pat.span) | |
866 | { | |
dfeec247 XL |
867 | Some(ty::BindByValue(hir::Mutability::Mut)) => { |
868 | mutability = Mutability::Mut; | |
869 | } | |
870 | Some(_) => mutability = Mutability::Not, | |
871 | _ => {} | |
60c5eb7d | 872 | } |
60c5eb7d XL |
873 | } |
874 | } | |
60c5eb7d | 875 | |
dfeec247 XL |
876 | let mut projs = closure_env_projs.clone(); |
877 | projs.push(ProjectionElem::Field(Field::new(i), ty)); | |
878 | match capture { | |
879 | ty::UpvarCapture::ByValue => {} | |
880 | ty::UpvarCapture::ByRef(..) => { | |
881 | projs.push(ProjectionElem::Deref); | |
882 | } | |
883 | }; | |
60c5eb7d | 884 | |
dfeec247 XL |
885 | self.var_debug_info.push(VarDebugInfo { |
886 | name, | |
f9f354fc | 887 | source_info: SourceInfo::outermost(tcx_hir.span(var_id)), |
dfeec247 | 888 | place: Place { |
74b04a01 | 889 | local: closure_env_arg, |
dfeec247 XL |
890 | projection: tcx.intern_place_elems(&projs), |
891 | }, | |
892 | }); | |
60c5eb7d | 893 | |
dfeec247 XL |
894 | mutability |
895 | }) | |
896 | .collect(); | |
c30ab7b3 SL |
897 | } |
898 | ||
3157f602 | 899 | let mut scope = None; |
c30ab7b3 | 900 | // Bind the argument patterns |
94b46f34 | 901 | for (index, arg_info) in arguments.iter().enumerate() { |
ff7c6d11 | 902 | // Function arguments always get the first Local indices after the return place |
abe05a73 | 903 | let local = Local::new(index + 1); |
dc9dc135 | 904 | let place = Place::from(local); |
e74abb32 | 905 | let &ArgInfo(_, opt_ty_info, arg_opt, ref self_binding) = arg_info; |
c30ab7b3 | 906 | |
0731742a XL |
907 | // Make sure we drop (parts of) the argument even when not matched on. |
908 | self.schedule_drop( | |
416331ca | 909 | arg_opt.as_ref().map_or(ast_body.span, |arg| arg.pat.span), |
dfeec247 XL |
910 | argument_scope, |
911 | local, | |
912 | DropKind::Value, | |
0731742a XL |
913 | ); |
914 | ||
416331ca XL |
915 | if let Some(arg) = arg_opt { |
916 | let pattern = self.hir.pattern_from_hir(&arg.pat); | |
917 | let original_source_scope = self.source_scope; | |
8faf50e0 | 918 | let span = pattern.span; |
416331ca | 919 | self.set_correct_source_scope_for_arg(arg.hir_id, original_source_scope, span); |
abe05a73 XL |
920 | match *pattern.kind { |
921 | // Don't introduce extra copies for simple bindings | |
e74abb32 | 922 | PatKind::Binding { |
dc9dc135 XL |
923 | mutability, |
924 | var, | |
925 | mode: BindingMode::ByValue, | |
926 | subpattern: None, | |
927 | .. | |
928 | } => { | |
abe05a73 | 929 | self.local_decls[local].mutability = mutability; |
416331ca | 930 | self.local_decls[local].source_info.scope = self.source_scope; |
dfeec247 | 931 | self.local_decls[local].local_info = if let Some(kind) = self_binding { |
f035d41b XL |
932 | Some(box LocalInfo::User(ClearCrossCrate::Set( |
933 | BindingForm::ImplicitSelf(*kind), | |
934 | ))) | |
dfeec247 | 935 | } else { |
74b04a01 | 936 | let binding_mode = ty::BindingMode::BindByValue(mutability); |
f9f354fc | 937 | Some(box LocalInfo::User(ClearCrossCrate::Set(BindingForm::Var( |
dfeec247 XL |
938 | VarBindingForm { |
939 | binding_mode, | |
940 | opt_ty_info, | |
941 | opt_match_place: Some((Some(place), span)), | |
942 | pat_span: span, | |
943 | }, | |
f9f354fc | 944 | )))) |
dfeec247 | 945 | }; |
83c7162d | 946 | self.var_indices.insert(var, LocalsForNode::One(local)); |
abe05a73 XL |
947 | } |
948 | _ => { | |
dc9dc135 XL |
949 | scope = self.declare_bindings( |
950 | scope, | |
951 | ast_body.span, | |
952 | &pattern, | |
953 | matches::ArmHasGuard(false), | |
954 | Some((Some(&place), span)), | |
955 | ); | |
74b04a01 | 956 | unpack!(block = self.place_into_pattern(block, pattern, place, false)); |
abe05a73 XL |
957 | } |
958 | } | |
416331ca | 959 | self.source_scope = original_source_scope; |
a7813a04 | 960 | } |
c30ab7b3 | 961 | } |
a7813a04 | 962 | |
94b46f34 XL |
963 | // Enter the argument pattern bindings source scope, if it exists. |
964 | if let Some(source_scope) = scope { | |
965 | self.source_scope = source_scope; | |
3157f602 XL |
966 | } |
967 | ||
476ff2be | 968 | let body = self.hir.mirror(ast_body); |
ba9703b0 | 969 | self.into(Place::return_place(), block, body) |
416331ca XL |
970 | } |
971 | ||
972 | fn set_correct_source_scope_for_arg( | |
973 | &mut self, | |
974 | arg_hir_id: hir::HirId, | |
975 | original_source_scope: SourceScope, | |
dfeec247 | 976 | pattern_span: Span, |
416331ca XL |
977 | ) { |
978 | let tcx = self.hir.tcx(); | |
dfeec247 | 979 | let current_root = tcx.maybe_lint_level_root_bounded(arg_hir_id, self.hir.root_lint_level); |
416331ca | 980 | let parent_root = tcx.maybe_lint_level_root_bounded( |
60c5eb7d XL |
981 | self.source_scopes[original_source_scope] |
982 | .local_data | |
983 | .as_ref() | |
984 | .assert_crate_local() | |
985 | .lint_root, | |
416331ca XL |
986 | self.hir.root_lint_level, |
987 | ); | |
988 | if current_root != parent_root { | |
dfeec247 XL |
989 | self.source_scope = |
990 | self.new_source_scope(pattern_span, LintLevel::Explicit(current_root), None); | |
416331ca | 991 | } |
e9174d1e | 992 | } |
7453a54e | 993 | |
ff7c6d11 | 994 | fn get_unit_temp(&mut self) -> Place<'tcx> { |
7453a54e | 995 | match self.unit_temp { |
dfeec247 | 996 | Some(tmp) => tmp, |
7453a54e SL |
997 | None => { |
998 | let ty = self.hir.unit_ty(); | |
cc61c64b XL |
999 | let fn_span = self.fn_span; |
1000 | let tmp = self.temp(ty, fn_span); | |
dfeec247 | 1001 | self.unit_temp = Some(tmp); |
7453a54e SL |
1002 | tmp |
1003 | } | |
1004 | } | |
1005 | } | |
a7813a04 XL |
1006 | |
1007 | fn return_block(&mut self) -> BasicBlock { | |
1008 | match self.cached_return_block { | |
1009 | Some(rb) => rb, | |
1010 | None => { | |
1011 | let rb = self.cfg.start_new_block(); | |
1012 | self.cached_return_block = Some(rb); | |
1013 | rb | |
1014 | } | |
1015 | } | |
1016 | } | |
e9174d1e SL |
1017 | } |
1018 | ||
1019 | /////////////////////////////////////////////////////////////////////////// | |
1020 | // Builder methods are broken up into modules, depending on what kind | |
94b46f34 | 1021 | // of thing is being lowered. Note that they use the `unpack` macro |
e9174d1e SL |
1022 | // above extensively. |
1023 | ||
1024 | mod block; | |
1025 | mod cfg; | |
1026 | mod expr; | |
1027 | mod into; | |
1028 | mod matches; | |
1029 | mod misc; | |
1030 | mod scope; |