]>
Commit | Line | Data |
---|---|---|
cc61c64b | 1 | use rustc::mir::*; |
a1dfa0c6 | 2 | use rustc::ty::layout::VariantIdx; |
94b46f34 | 3 | use rustc::ty::query::Providers; |
dfeec247 XL |
4 | use rustc::ty::subst::{InternalSubsts, Subst}; |
5 | use rustc::ty::{self, Ty, TyCtxt}; | |
6 | use rustc_hir as hir; | |
7 | use rustc_hir::def_id::DefId; | |
cc61c64b | 8 | |
dfeec247 | 9 | use rustc_index::vec::{Idx, IndexVec}; |
cc61c64b | 10 | |
dfeec247 | 11 | use rustc_span::{sym, Span}; |
83c7162d | 12 | use rustc_target::spec::abi::Abi; |
cc61c64b | 13 | |
cc61c64b XL |
14 | use std::fmt; |
15 | use std::iter; | |
cc61c64b | 16 | |
9fa01778 | 17 | use crate::transform::{ |
dfeec247 XL |
18 | add_call_guards, add_moves_for_packed_drops, no_landing_pads, remove_noop_landing_pads, |
19 | run_passes, simplify, | |
9fa01778 | 20 | }; |
dfeec247 | 21 | use crate::util::elaborate_drops::{self, DropElaborator, DropFlagMode, DropStyle}; |
dc9dc135 | 22 | use crate::util::expand_aggregate; |
dfeec247 | 23 | use crate::util::patch::MirPatch; |
9fa01778 XL |
24 | |
25 | pub fn provide(providers: &mut Providers<'_>) { | |
cc61c64b XL |
26 | providers.mir_shims = make_shim; |
27 | } | |
28 | ||
60c5eb7d | 29 | fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> &'tcx BodyAndCache<'tcx> { |
cc61c64b | 30 | debug!("make_shim({:?})", instance); |
cc61c64b XL |
31 | |
32 | let mut result = match instance { | |
dfeec247 XL |
33 | ty::InstanceDef::Item(..) => bug!("item {:?} passed to make_shim", instance), |
34 | ty::InstanceDef::VtableShim(def_id) => build_call_shim( | |
35 | tcx, | |
36 | instance, | |
37 | Some(Adjustment::DerefMove), | |
38 | CallKind::Direct(def_id), | |
39 | None, | |
40 | ), | |
cc61c64b XL |
41 | ty::InstanceDef::FnPtrShim(def_id, ty) => { |
42 | let trait_ = tcx.trait_of_item(def_id).unwrap(); | |
74b04a01 | 43 | let adjustment = match tcx.fn_trait_kind_from_lang_item(trait_) { |
cc61c64b | 44 | Some(ty::ClosureKind::FnOnce) => Adjustment::Identity, |
dfeec247 XL |
45 | Some(ty::ClosureKind::FnMut) | Some(ty::ClosureKind::Fn) => Adjustment::Deref, |
46 | None => bug!("fn pointer {:?} is not an fn", ty), | |
cc61c64b XL |
47 | }; |
48 | // HACK: we need the "real" argument types for the MIR, | |
49 | // but because our substs are (Self, Args), where Args | |
50 | // is a tuple, we must include the *concrete* argument | |
51 | // types in the MIR. They will be substituted again with | |
52 | // the param-substs, but because they are concrete, this | |
53 | // will not do any harm. | |
041b39d2 | 54 | let sig = tcx.erase_late_bound_regions(&ty.fn_sig(tcx)); |
cc61c64b XL |
55 | let arg_tys = sig.inputs(); |
56 | ||
dfeec247 | 57 | build_call_shim(tcx, instance, Some(adjustment), CallKind::Indirect, Some(arg_tys)) |
cc61c64b | 58 | } |
e74abb32 | 59 | // We are generating a call back to our def-id, which the |
60c5eb7d XL |
60 | // codegen backend knows to turn to an actual call, be it |
61 | // a virtual call, or a direct call to a function for which | |
62 | // indirect calls must be codegen'd differently than direct ones | |
63 | // (such as `#[track_caller]`). | |
e74abb32 | 64 | ty::InstanceDef::ReifyShim(def_id) => { |
dfeec247 | 65 | build_call_shim(tcx, instance, None, CallKind::Direct(def_id), None) |
cc61c64b | 66 | } |
60c5eb7d | 67 | ty::InstanceDef::ClosureOnceShim { call_once: _ } => { |
ea8adc8c | 68 | let fn_mut = tcx.lang_items().fn_mut_trait().unwrap(); |
e74abb32 | 69 | let call_mut = tcx |
cc61c64b | 70 | .associated_items(fn_mut) |
74b04a01 | 71 | .in_definition_order() |
dc9dc135 | 72 | .find(|it| it.kind == ty::AssocKind::Method) |
dfeec247 XL |
73 | .unwrap() |
74 | .def_id; | |
cc61c64b XL |
75 | |
76 | build_call_shim( | |
77 | tcx, | |
60c5eb7d | 78 | instance, |
dfeec247 | 79 | Some(Adjustment::RefMut), |
cc61c64b | 80 | CallKind::Direct(call_mut), |
dfeec247 | 81 | None, |
cc61c64b XL |
82 | ) |
83 | } | |
dfeec247 | 84 | ty::InstanceDef::DropGlue(def_id, ty) => build_drop_shim(tcx, def_id, ty), |
3b2f2976 | 85 | ty::InstanceDef::CloneShim(def_id, ty) => { |
ea8adc8c | 86 | let name = tcx.item_name(def_id); |
dc9dc135 | 87 | if name == sym::clone { |
3b2f2976 | 88 | build_clone_shim(tcx, def_id, ty) |
dc9dc135 | 89 | } else if name == sym::clone_from { |
3b2f2976 XL |
90 | debug!("make_shim({:?}: using default trait implementation", instance); |
91 | return tcx.optimized_mir(def_id); | |
92 | } else { | |
93 | bug!("builtin clone shim {:?} not supported", instance) | |
94 | } | |
95 | } | |
60c5eb7d XL |
96 | ty::InstanceDef::Virtual(..) => { |
97 | bug!("InstanceDef::Virtual ({:?}) is for direct calls only", instance) | |
98 | } | |
cc61c64b XL |
99 | ty::InstanceDef::Intrinsic(_) => { |
100 | bug!("creating shims from intrinsics ({:?}) is unsupported", instance) | |
101 | } | |
102 | }; | |
3b2f2976 | 103 | debug!("make_shim({:?}) = untransformed {:?}", instance, result); |
9fa01778 | 104 | |
dfeec247 XL |
105 | run_passes( |
106 | tcx, | |
107 | &mut result, | |
108 | instance, | |
109 | None, | |
110 | MirPhase::Const, | |
111 | &[ | |
112 | &add_moves_for_packed_drops::AddMovesForPackedDrops, | |
113 | &no_landing_pads::NoLandingPads::new(tcx), | |
114 | &remove_noop_landing_pads::RemoveNoopLandingPads, | |
115 | &simplify::SimplifyCfg::new("make_shim"), | |
116 | &add_call_guards::CriticalCallEdges, | |
117 | ], | |
118 | ); | |
9fa01778 | 119 | |
cc61c64b XL |
120 | debug!("make_shim({:?}) = {:?}", instance, result); |
121 | ||
60c5eb7d | 122 | result.ensure_predecessors(); |
dc9dc135 | 123 | tcx.arena.alloc(result) |
cc61c64b XL |
124 | } |
125 | ||
126 | #[derive(Copy, Clone, Debug, PartialEq)] | |
127 | enum Adjustment { | |
128 | Identity, | |
129 | Deref, | |
a1dfa0c6 | 130 | DerefMove, |
cc61c64b XL |
131 | RefMut, |
132 | } | |
133 | ||
134 | #[derive(Copy, Clone, Debug, PartialEq)] | |
135 | enum CallKind { | |
136 | Indirect, | |
137 | Direct(DefId), | |
138 | } | |
139 | ||
9fa01778 | 140 | fn temp_decl(mutability: Mutability, ty: Ty<'_>, span: Span) -> LocalDecl<'_> { |
94b46f34 | 141 | let source_info = SourceInfo { scope: OUTERMOST_SOURCE_SCOPE, span }; |
cc61c64b | 142 | LocalDecl { |
0bf4aa26 XL |
143 | mutability, |
144 | ty, | |
145 | user_ty: UserTypeProjections::none(), | |
94b46f34 | 146 | source_info, |
ea8adc8c | 147 | internal: false, |
60c5eb7d | 148 | local_info: LocalInfo::Other, |
0bf4aa26 | 149 | is_block_tail: None, |
cc61c64b XL |
150 | } |
151 | } | |
152 | ||
dfeec247 XL |
153 | fn local_decls_for_sig<'tcx>( |
154 | sig: &ty::FnSig<'tcx>, | |
155 | span: Span, | |
156 | ) -> IndexVec<Local, LocalDecl<'tcx>> { | |
cc61c64b | 157 | iter::once(temp_decl(Mutability::Mut, sig.output(), span)) |
dfeec247 | 158 | .chain(sig.inputs().iter().map(|ity| temp_decl(Mutability::Not, ity, span))) |
cc61c64b XL |
159 | .collect() |
160 | } | |
161 | ||
60c5eb7d | 162 | fn build_drop_shim<'tcx>( |
dfeec247 XL |
163 | tcx: TyCtxt<'tcx>, |
164 | def_id: DefId, | |
165 | ty: Option<Ty<'tcx>>, | |
60c5eb7d | 166 | ) -> BodyAndCache<'tcx> { |
cc61c64b XL |
167 | debug!("build_drop_shim(def_id={:?}, ty={:?})", def_id, ty); |
168 | ||
ea8adc8c | 169 | // Check if this is a generator, if so, return the drop glue for it |
e74abb32 | 170 | if let Some(&ty::TyS { kind: ty::Generator(gen_def_id, substs, _), .. }) = ty { |
dc9dc135 | 171 | let body = &**tcx.optimized_mir(gen_def_id).generator_drop.as_ref().unwrap(); |
e74abb32 | 172 | return body.subst(tcx, substs); |
ea8adc8c XL |
173 | } |
174 | ||
cc61c64b | 175 | let substs = if let Some(ty) = ty { |
94b46f34 | 176 | tcx.intern_substs(&[ty.into()]) |
cc61c64b | 177 | } else { |
532ac7d7 | 178 | InternalSubsts::identity_for_item(tcx, def_id) |
cc61c64b | 179 | }; |
041b39d2 XL |
180 | let sig = tcx.fn_sig(def_id).subst(tcx, substs); |
181 | let sig = tcx.erase_late_bound_regions(&sig); | |
cc61c64b XL |
182 | let span = tcx.def_span(def_id); |
183 | ||
94b46f34 | 184 | let source_info = SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }; |
cc61c64b XL |
185 | |
186 | let return_block = BasicBlock::new(1); | |
a1dfa0c6 | 187 | let mut blocks = IndexVec::with_capacity(2); |
cc61c64b XL |
188 | let block = |blocks: &mut IndexVec<_, _>, kind| { |
189 | blocks.push(BasicBlockData { | |
190 | statements: vec![], | |
191 | terminator: Some(Terminator { source_info, kind }), | |
dfeec247 | 192 | is_cleanup: false, |
cc61c64b XL |
193 | }) |
194 | }; | |
195 | block(&mut blocks, TerminatorKind::Goto { target: return_block }); | |
196 | block(&mut blocks, TerminatorKind::Return); | |
197 | ||
dfeec247 | 198 | let body = new_body(blocks, local_decls_for_sig(&sig, span), sig.inputs().len(), span); |
60c5eb7d XL |
199 | |
200 | let mut body = BodyAndCache::new(body); | |
cc61c64b XL |
201 | |
202 | if let Some(..) = ty { | |
a1dfa0c6 | 203 | // The first argument (index 0), but add 1 for the return value. |
dfeec247 | 204 | let dropee_ptr = Place::from(Local::new(1 + 0)); |
a1dfa0c6 | 205 | if tcx.sess.opts.debugging_opts.mir_emit_retag { |
0731742a | 206 | // Function arguments should be retagged, and we make this one raw. |
dfeec247 XL |
207 | body.basic_blocks_mut()[START_BLOCK].statements.insert( |
208 | 0, | |
209 | Statement { | |
210 | source_info, | |
211 | kind: StatementKind::Retag(RetagKind::Raw, box (dropee_ptr)), | |
212 | }, | |
213 | ); | |
a1dfa0c6 | 214 | } |
cc61c64b | 215 | let patch = { |
0531ce1d | 216 | let param_env = tcx.param_env(def_id).with_reveal_all(); |
dfeec247 XL |
217 | let mut elaborator = |
218 | DropShimElaborator { body: &body, patch: MirPatch::new(&body), tcx, param_env }; | |
e74abb32 | 219 | let dropee = tcx.mk_place_deref(dropee_ptr); |
cc61c64b XL |
220 | let resume_block = elaborator.patch.resume_block(); |
221 | elaborate_drops::elaborate_drop( | |
222 | &mut elaborator, | |
223 | source_info, | |
cc61c64b XL |
224 | &dropee, |
225 | (), | |
226 | return_block, | |
7cac9316 | 227 | elaborate_drops::Unwind::To(resume_block), |
dfeec247 | 228 | START_BLOCK, |
cc61c64b XL |
229 | ); |
230 | elaborator.patch | |
231 | }; | |
dc9dc135 | 232 | patch.apply(&mut body); |
cc61c64b XL |
233 | } |
234 | ||
dc9dc135 | 235 | body |
cc61c64b XL |
236 | } |
237 | ||
60c5eb7d XL |
238 | fn new_body<'tcx>( |
239 | basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>, | |
240 | local_decls: IndexVec<Local, LocalDecl<'tcx>>, | |
241 | arg_count: usize, | |
242 | span: Span, | |
243 | ) -> Body<'tcx> { | |
244 | Body::new( | |
245 | basic_blocks, | |
246 | IndexVec::from_elem_n( | |
247 | SourceScopeData { span, parent_scope: None, local_data: ClearCrossCrate::Clear }, | |
248 | 1, | |
249 | ), | |
250 | local_decls, | |
251 | IndexVec::new(), | |
252 | arg_count, | |
253 | vec![], | |
254 | span, | |
255 | vec![], | |
256 | None, | |
257 | ) | |
258 | } | |
259 | ||
dc9dc135 XL |
260 | pub struct DropShimElaborator<'a, 'tcx> { |
261 | pub body: &'a Body<'tcx>, | |
ea8adc8c | 262 | pub patch: MirPatch<'tcx>, |
dc9dc135 | 263 | pub tcx: TyCtxt<'tcx>, |
ea8adc8c | 264 | pub param_env: ty::ParamEnv<'tcx>, |
cc61c64b XL |
265 | } |
266 | ||
267 | impl<'a, 'tcx> fmt::Debug for DropShimElaborator<'a, 'tcx> { | |
9fa01778 | 268 | fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> { |
cc61c64b XL |
269 | Ok(()) |
270 | } | |
271 | } | |
272 | ||
273 | impl<'a, 'tcx> DropElaborator<'a, 'tcx> for DropShimElaborator<'a, 'tcx> { | |
274 | type Path = (); | |
275 | ||
dfeec247 XL |
276 | fn patch(&mut self) -> &mut MirPatch<'tcx> { |
277 | &mut self.patch | |
278 | } | |
279 | fn body(&self) -> &'a Body<'tcx> { | |
280 | self.body | |
281 | } | |
dc9dc135 XL |
282 | fn tcx(&self) -> TyCtxt<'tcx> { |
283 | self.tcx | |
dfeec247 XL |
284 | } |
285 | fn param_env(&self) -> ty::ParamEnv<'tcx> { | |
286 | self.param_env | |
287 | } | |
cc61c64b XL |
288 | |
289 | fn drop_style(&self, _path: Self::Path, mode: DropFlagMode) -> DropStyle { | |
dfeec247 | 290 | if let DropFlagMode::Shallow = mode { DropStyle::Static } else { DropStyle::Open } |
cc61c64b XL |
291 | } |
292 | ||
293 | fn get_drop_flag(&mut self, _path: Self::Path) -> Option<Operand<'tcx>> { | |
294 | None | |
295 | } | |
296 | ||
dfeec247 | 297 | fn clear_drop_flag(&mut self, _location: Location, _path: Self::Path, _mode: DropFlagMode) {} |
cc61c64b XL |
298 | |
299 | fn field_subpath(&self, _path: Self::Path, _field: Field) -> Option<Self::Path> { | |
300 | None | |
301 | } | |
302 | fn deref_subpath(&self, _path: Self::Path) -> Option<Self::Path> { | |
303 | None | |
304 | } | |
a1dfa0c6 | 305 | fn downcast_subpath(&self, _path: Self::Path, _variant: VariantIdx) -> Option<Self::Path> { |
cc61c64b XL |
306 | Some(()) |
307 | } | |
ff7c6d11 XL |
308 | fn array_subpath(&self, _path: Self::Path, _index: u32, _size: u32) -> Option<Self::Path> { |
309 | None | |
310 | } | |
cc61c64b XL |
311 | } |
312 | ||
9fa01778 | 313 | /// Builds a `Clone::clone` shim for `self_ty`. Here, `def_id` is `Clone::clone`. |
60c5eb7d XL |
314 | fn build_clone_shim<'tcx>( |
315 | tcx: TyCtxt<'tcx>, | |
316 | def_id: DefId, | |
317 | self_ty: Ty<'tcx>, | |
318 | ) -> BodyAndCache<'tcx> { | |
3b2f2976 XL |
319 | debug!("build_clone_shim(def_id={:?})", def_id); |
320 | ||
416331ca XL |
321 | let param_env = tcx.param_env(def_id); |
322 | ||
2c00a5a8 | 323 | let mut builder = CloneShimBuilder::new(tcx, def_id, self_ty); |
416331ca | 324 | let is_copy = self_ty.is_copy_modulo_regions(tcx, param_env, builder.span); |
3b2f2976 | 325 | |
e1599b0c | 326 | let dest = Place::return_place(); |
dfeec247 | 327 | let src = tcx.mk_place_deref(Place::from(Local::new(1 + 0))); |
2c00a5a8 | 328 | |
e74abb32 | 329 | match self_ty.kind { |
3b2f2976 | 330 | _ if is_copy => builder.copy_shim(), |
b7449926 | 331 | ty::Array(ty, len) => { |
416331ca | 332 | let len = len.eval_usize(tcx, param_env); |
2c00a5a8 | 333 | builder.array_shim(dest, src, ty, len) |
ea8adc8c | 334 | } |
b7449926 | 335 | ty::Closure(def_id, substs) => { |
dfeec247 | 336 | builder.tuple_like_shim(dest, src, substs.as_closure().upvar_tys(def_id, tcx)) |
ea8adc8c | 337 | } |
416331ca | 338 | ty::Tuple(..) => builder.tuple_like_shim(dest, src, self_ty.tuple_fields()), |
dfeec247 | 339 | _ => bug!("clone shim for `{:?}` which is not `Copy` and is not an aggregate", self_ty), |
3b2f2976 XL |
340 | }; |
341 | ||
60c5eb7d | 342 | BodyAndCache::new(builder.into_mir()) |
3b2f2976 XL |
343 | } |
344 | ||
dc9dc135 XL |
345 | struct CloneShimBuilder<'tcx> { |
346 | tcx: TyCtxt<'tcx>, | |
3b2f2976 XL |
347 | def_id: DefId, |
348 | local_decls: IndexVec<Local, LocalDecl<'tcx>>, | |
349 | blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>, | |
350 | span: Span, | |
351 | sig: ty::FnSig<'tcx>, | |
352 | } | |
353 | ||
dc9dc135 XL |
354 | impl CloneShimBuilder<'tcx> { |
355 | fn new(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Self { | |
2c00a5a8 XL |
356 | // we must subst the self_ty because it's |
357 | // otherwise going to be TySelf and we can't index | |
358 | // or access fields of a Place of type TySelf. | |
359 | let substs = tcx.mk_substs_trait(self_ty, &[]); | |
360 | let sig = tcx.fn_sig(def_id).subst(tcx, substs); | |
3b2f2976 XL |
361 | let sig = tcx.erase_late_bound_regions(&sig); |
362 | let span = tcx.def_span(def_id); | |
363 | ||
364 | CloneShimBuilder { | |
365 | tcx, | |
366 | def_id, | |
367 | local_decls: local_decls_for_sig(&sig, span), | |
368 | blocks: IndexVec::new(), | |
369 | span, | |
370 | sig, | |
371 | } | |
372 | } | |
373 | ||
dc9dc135 | 374 | fn into_mir(self) -> Body<'tcx> { |
dfeec247 | 375 | new_body(self.blocks, self.local_decls, self.sig.inputs().len(), self.span) |
3b2f2976 XL |
376 | } |
377 | ||
378 | fn source_info(&self) -> SourceInfo { | |
94b46f34 | 379 | SourceInfo { span: self.span, scope: OUTERMOST_SOURCE_SCOPE } |
3b2f2976 XL |
380 | } |
381 | ||
382 | fn block( | |
383 | &mut self, | |
384 | statements: Vec<Statement<'tcx>>, | |
385 | kind: TerminatorKind<'tcx>, | |
dfeec247 | 386 | is_cleanup: bool, |
3b2f2976 XL |
387 | ) -> BasicBlock { |
388 | let source_info = self.source_info(); | |
389 | self.blocks.push(BasicBlockData { | |
390 | statements, | |
391 | terminator: Some(Terminator { source_info, kind }), | |
392 | is_cleanup, | |
393 | }) | |
394 | } | |
395 | ||
2c00a5a8 XL |
396 | /// Gives the index of an upcoming BasicBlock, with an offset. |
397 | /// offset=0 will give you the index of the next BasicBlock, | |
398 | /// offset=1 will give the index of the next-to-next block, | |
399 | /// offset=-1 will give you the index of the last-created block | |
400 | fn block_index_offset(&mut self, offset: usize) -> BasicBlock { | |
401 | BasicBlock::new(self.blocks.len() + offset) | |
402 | } | |
403 | ||
3b2f2976 | 404 | fn make_statement(&self, kind: StatementKind<'tcx>) -> Statement<'tcx> { |
dfeec247 | 405 | Statement { source_info: self.source_info(), kind } |
3b2f2976 XL |
406 | } |
407 | ||
408 | fn copy_shim(&mut self) { | |
dfeec247 XL |
409 | let rcvr = self.tcx.mk_place_deref(Place::from(Local::new(1 + 0))); |
410 | let ret_statement = self.make_statement(StatementKind::Assign(box ( | |
411 | Place::return_place(), | |
412 | Rvalue::Use(Operand::Copy(rcvr)), | |
413 | ))); | |
3b2f2976 XL |
414 | self.block(vec![ret_statement], TerminatorKind::Return, false); |
415 | } | |
416 | ||
ff7c6d11 | 417 | fn make_place(&mut self, mutability: Mutability, ty: Ty<'tcx>) -> Place<'tcx> { |
3b2f2976 | 418 | let span = self.span; |
dc9dc135 | 419 | Place::from(self.local_decls.push(temp_decl(mutability, ty, span))) |
3b2f2976 XL |
420 | } |
421 | ||
422 | fn make_clone_call( | |
423 | &mut self, | |
2c00a5a8 XL |
424 | dest: Place<'tcx>, |
425 | src: Place<'tcx>, | |
ea8adc8c | 426 | ty: Ty<'tcx>, |
3b2f2976 | 427 | next: BasicBlock, |
dfeec247 | 428 | cleanup: BasicBlock, |
2c00a5a8 | 429 | ) { |
3b2f2976 XL |
430 | let tcx = self.tcx; |
431 | ||
532ac7d7 | 432 | let substs = tcx.mk_substs_trait(ty, &[]); |
3b2f2976 XL |
433 | |
434 | // `func == Clone::clone(&ty) -> ty` | |
ea8adc8c | 435 | let func_ty = tcx.mk_fn_def(self.def_id, substs); |
3b2f2976 XL |
436 | let func = Operand::Constant(box Constant { |
437 | span: self.span, | |
b7449926 | 438 | user_ty: None, |
dc9dc135 | 439 | literal: ty::Const::zero_sized(tcx, func_ty), |
3b2f2976 XL |
440 | }); |
441 | ||
ff7c6d11 | 442 | let ref_loc = self.make_place( |
3b2f2976 | 443 | Mutability::Not, |
dfeec247 | 444 | tcx.mk_ref(tcx.lifetimes.re_erased, ty::TypeAndMut { ty, mutbl: hir::Mutability::Not }), |
3b2f2976 XL |
445 | ); |
446 | ||
2c00a5a8 | 447 | // `let ref_loc: &ty = &src;` |
dfeec247 XL |
448 | let statement = self.make_statement(StatementKind::Assign(box ( |
449 | ref_loc, | |
450 | Rvalue::Ref(tcx.lifetimes.re_erased, BorrowKind::Shared, src), | |
451 | ))); | |
3b2f2976 XL |
452 | |
453 | // `let loc = Clone::clone(ref_loc);` | |
dfeec247 XL |
454 | self.block( |
455 | vec![statement], | |
456 | TerminatorKind::Call { | |
457 | func, | |
458 | args: vec![Operand::Move(ref_loc)], | |
459 | destination: Some((dest, next)), | |
460 | cleanup: Some(cleanup), | |
461 | from_hir_call: true, | |
462 | }, | |
463 | false, | |
464 | ); | |
3b2f2976 XL |
465 | } |
466 | ||
467 | fn loop_header( | |
468 | &mut self, | |
ff7c6d11 XL |
469 | beg: Place<'tcx>, |
470 | end: Place<'tcx>, | |
3b2f2976 XL |
471 | loop_body: BasicBlock, |
472 | loop_end: BasicBlock, | |
dfeec247 | 473 | is_cleanup: bool, |
3b2f2976 XL |
474 | ) { |
475 | let tcx = self.tcx; | |
476 | ||
ff7c6d11 | 477 | let cond = self.make_place(Mutability::Mut, tcx.types.bool); |
dfeec247 XL |
478 | let compute_cond = self.make_statement(StatementKind::Assign(box ( |
479 | cond, | |
480 | Rvalue::BinaryOp(BinOp::Ne, Operand::Copy(end), Operand::Copy(beg)), | |
481 | ))); | |
3b2f2976 XL |
482 | |
483 | // `if end != beg { goto loop_body; } else { goto loop_end; }` | |
484 | self.block( | |
485 | vec![compute_cond], | |
ff7c6d11 | 486 | TerminatorKind::if_(tcx, Operand::Move(cond), loop_body, loop_end), |
dfeec247 | 487 | is_cleanup, |
3b2f2976 XL |
488 | ); |
489 | } | |
490 | ||
ea8adc8c | 491 | fn make_usize(&self, value: u64) -> Box<Constant<'tcx>> { |
3b2f2976 XL |
492 | box Constant { |
493 | span: self.span, | |
b7449926 | 494 | user_ty: None, |
dc9dc135 | 495 | literal: ty::Const::from_usize(self.tcx, value), |
3b2f2976 XL |
496 | } |
497 | } | |
498 | ||
2c00a5a8 | 499 | fn array_shim(&mut self, dest: Place<'tcx>, src: Place<'tcx>, ty: Ty<'tcx>, len: u64) { |
3b2f2976 | 500 | let tcx = self.tcx; |
ea8adc8c | 501 | let span = self.span; |
3b2f2976 | 502 | |
ea8adc8c | 503 | let beg = self.local_decls.push(temp_decl(Mutability::Mut, tcx.types.usize, span)); |
ff7c6d11 | 504 | let end = self.make_place(Mutability::Not, tcx.types.usize); |
3b2f2976 XL |
505 | |
506 | // BB #0 | |
507 | // `let mut beg = 0;` | |
508 | // `let end = len;` | |
509 | // `goto #1;` | |
510 | let inits = vec![ | |
dfeec247 XL |
511 | self.make_statement(StatementKind::Assign(box ( |
512 | Place::from(beg), | |
513 | Rvalue::Use(Operand::Constant(self.make_usize(0))), | |
514 | ))), | |
515 | self.make_statement(StatementKind::Assign(box ( | |
516 | end, | |
517 | Rvalue::Use(Operand::Constant(self.make_usize(len))), | |
518 | ))), | |
3b2f2976 XL |
519 | ]; |
520 | self.block(inits, TerminatorKind::Goto { target: BasicBlock::new(1) }, false); | |
521 | ||
522 | // BB #1: loop { | |
523 | // BB #2; | |
524 | // BB #3; | |
525 | // } | |
526 | // BB #4; | |
dfeec247 | 527 | self.loop_header(Place::from(beg), end, BasicBlock::new(2), BasicBlock::new(4), false); |
3b2f2976 XL |
528 | |
529 | // BB #2 | |
2c00a5a8 | 530 | // `dest[i] = Clone::clone(src[beg])`; |
3b2f2976 | 531 | // Goto #3 if ok, #5 if unwinding happens. |
e74abb32 XL |
532 | let dest_field = self.tcx.mk_place_index(dest.clone(), beg); |
533 | let src_field = self.tcx.mk_place_index(src, beg); | |
dfeec247 | 534 | self.make_clone_call(dest_field, src_field, ty, BasicBlock::new(3), BasicBlock::new(5)); |
3b2f2976 XL |
535 | |
536 | // BB #3 | |
3b2f2976 XL |
537 | // `beg = beg + 1;` |
538 | // `goto #1`; | |
dfeec247 XL |
539 | let statements = vec![self.make_statement(StatementKind::Assign(box ( |
540 | Place::from(beg), | |
541 | Rvalue::BinaryOp( | |
542 | BinOp::Add, | |
543 | Operand::Copy(Place::from(beg)), | |
544 | Operand::Constant(self.make_usize(1)), | |
545 | ), | |
546 | )))]; | |
3b2f2976 XL |
547 | self.block(statements, TerminatorKind::Goto { target: BasicBlock::new(1) }, false); |
548 | ||
549 | // BB #4 | |
2c00a5a8 XL |
550 | // `return dest;` |
551 | self.block(vec![], TerminatorKind::Return, false); | |
3b2f2976 XL |
552 | |
553 | // BB #5 (cleanup) | |
554 | // `let end = beg;` | |
555 | // `let mut beg = 0;` | |
556 | // goto #6; | |
557 | let end = beg; | |
ea8adc8c | 558 | let beg = self.local_decls.push(temp_decl(Mutability::Mut, tcx.types.usize, span)); |
dfeec247 XL |
559 | let init = self.make_statement(StatementKind::Assign(box ( |
560 | Place::from(beg), | |
561 | Rvalue::Use(Operand::Constant(self.make_usize(0))), | |
562 | ))); | |
3b2f2976 XL |
563 | self.block(vec![init], TerminatorKind::Goto { target: BasicBlock::new(6) }, true); |
564 | ||
565 | // BB #6 (cleanup): loop { | |
566 | // BB #7; | |
567 | // BB #8; | |
568 | // } | |
569 | // BB #9; | |
dfeec247 XL |
570 | self.loop_header( |
571 | Place::from(beg), | |
572 | Place::from(end), | |
573 | BasicBlock::new(7), | |
574 | BasicBlock::new(9), | |
575 | true, | |
576 | ); | |
3b2f2976 XL |
577 | |
578 | // BB #7 (cleanup) | |
2c00a5a8 | 579 | // `drop(dest[beg])`; |
dfeec247 XL |
580 | self.block( |
581 | vec![], | |
582 | TerminatorKind::Drop { | |
583 | location: self.tcx.mk_place_index(dest, beg), | |
584 | target: BasicBlock::new(8), | |
585 | unwind: None, | |
586 | }, | |
587 | true, | |
588 | ); | |
3b2f2976 XL |
589 | |
590 | // BB #8 (cleanup) | |
591 | // `beg = beg + 1;` | |
592 | // `goto #6;` | |
dfeec247 XL |
593 | let statement = self.make_statement(StatementKind::Assign(box ( |
594 | Place::from(beg), | |
595 | Rvalue::BinaryOp( | |
596 | BinOp::Add, | |
597 | Operand::Copy(Place::from(beg)), | |
598 | Operand::Constant(self.make_usize(1)), | |
599 | ), | |
600 | ))); | |
3b2f2976 XL |
601 | self.block(vec![statement], TerminatorKind::Goto { target: BasicBlock::new(6) }, true); |
602 | ||
603 | // BB #9 (resume) | |
604 | self.block(vec![], TerminatorKind::Resume, true); | |
605 | } | |
606 | ||
dfeec247 XL |
607 | fn tuple_like_shim<I>(&mut self, dest: Place<'tcx>, src: Place<'tcx>, tys: I) |
608 | where | |
609 | I: Iterator<Item = Ty<'tcx>>, | |
610 | { | |
2c00a5a8 XL |
611 | let mut previous_field = None; |
612 | for (i, ity) in tys.enumerate() { | |
613 | let field = Field::new(i); | |
e74abb32 | 614 | let src_field = self.tcx.mk_place_field(src.clone(), field, ity); |
ea8adc8c | 615 | |
e74abb32 | 616 | let dest_field = self.tcx.mk_place_field(dest.clone(), field, ity); |
3b2f2976 | 617 | |
2c00a5a8 XL |
618 | // #(2i + 1) is the cleanup block for the previous clone operation |
619 | let cleanup_block = self.block_index_offset(1); | |
620 | // #(2i + 2) is the next cloning block | |
621 | // (or the Return terminator if this is the last block) | |
622 | let next_block = self.block_index_offset(2); | |
3b2f2976 XL |
623 | |
624 | // BB #(2i) | |
2c00a5a8 | 625 | // `dest.i = Clone::clone(&src.i);` |
3b2f2976 | 626 | // Goto #(2i + 2) if ok, #(2i + 1) if unwinding happens. |
dfeec247 | 627 | self.make_clone_call(dest_field.clone(), src_field, ity, next_block, cleanup_block); |
3b2f2976 XL |
628 | |
629 | // BB #(2i + 1) (cleanup) | |
2c00a5a8 | 630 | if let Some((previous_field, previous_cleanup)) = previous_field.take() { |
3b2f2976 | 631 | // Drop previous field and goto previous cleanup block. |
dfeec247 XL |
632 | self.block( |
633 | vec![], | |
634 | TerminatorKind::Drop { | |
635 | location: previous_field, | |
636 | target: previous_cleanup, | |
637 | unwind: None, | |
638 | }, | |
639 | true, | |
640 | ); | |
2c00a5a8 XL |
641 | } else { |
642 | // Nothing to drop, just resume. | |
643 | self.block(vec![], TerminatorKind::Resume, true); | |
3b2f2976 | 644 | } |
2c00a5a8 XL |
645 | |
646 | previous_field = Some((dest_field, cleanup_block)); | |
3b2f2976 XL |
647 | } |
648 | ||
2c00a5a8 | 649 | self.block(vec![], TerminatorKind::Return, false); |
3b2f2976 XL |
650 | } |
651 | } | |
652 | ||
60c5eb7d | 653 | /// Builds a "call" shim for `instance`. The shim calls the |
cc61c64b XL |
654 | /// function specified by `call_kind`, first adjusting its first |
655 | /// argument according to `rcvr_adjustment`. | |
656 | /// | |
657 | /// If `untuple_args` is a vec of types, the second argument of the | |
658 | /// function will be untupled as these types. | |
dc9dc135 XL |
659 | fn build_call_shim<'tcx>( |
660 | tcx: TyCtxt<'tcx>, | |
60c5eb7d | 661 | instance: ty::InstanceDef<'tcx>, |
dfeec247 | 662 | rcvr_adjustment: Option<Adjustment>, |
dc9dc135 XL |
663 | call_kind: CallKind, |
664 | untuple_args: Option<&[Ty<'tcx>]>, | |
60c5eb7d | 665 | ) -> BodyAndCache<'tcx> { |
dfeec247 XL |
666 | debug!( |
667 | "build_call_shim(instance={:?}, rcvr_adjustment={:?}, \ | |
cc61c64b | 668 | call_kind={:?}, untuple_args={:?})", |
dfeec247 XL |
669 | instance, rcvr_adjustment, call_kind, untuple_args |
670 | ); | |
cc61c64b | 671 | |
60c5eb7d | 672 | let def_id = instance.def_id(); |
041b39d2 | 673 | let sig = tcx.fn_sig(def_id); |
60c5eb7d XL |
674 | let mut sig = tcx.erase_late_bound_regions(&sig); |
675 | ||
676 | // FIXME(eddyb) avoid having this snippet both here and in | |
677 | // `Instance::fn_sig` (introduce `InstanceDef::fn_sig`?). | |
678 | if let ty::InstanceDef::VtableShim(..) = instance { | |
679 | // Modify fn(self, ...) to fn(self: *mut Self, ...) | |
680 | let mut inputs_and_output = sig.inputs_and_output.to_vec(); | |
681 | let self_arg = &mut inputs_and_output[0]; | |
682 | debug_assert!(tcx.generics_of(def_id).has_self && *self_arg == tcx.types.self_param); | |
683 | *self_arg = tcx.mk_mut_ptr(*self_arg); | |
684 | sig.inputs_and_output = tcx.intern_type_list(&inputs_and_output); | |
685 | } | |
686 | ||
cc61c64b XL |
687 | let span = tcx.def_span(def_id); |
688 | ||
689 | debug!("build_call_shim: sig={:?}", sig); | |
690 | ||
691 | let mut local_decls = local_decls_for_sig(&sig, span); | |
94b46f34 | 692 | let source_info = SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }; |
cc61c64b | 693 | |
dfeec247 XL |
694 | let rcvr_place = || { |
695 | assert!(rcvr_adjustment.is_some()); | |
696 | Place::from(Local::new(1 + 0)) | |
697 | }; | |
cc61c64b XL |
698 | let mut statements = vec![]; |
699 | ||
dfeec247 XL |
700 | let rcvr = rcvr_adjustment.map(|rcvr_adjustment| match rcvr_adjustment { |
701 | Adjustment::Identity => Operand::Move(rcvr_place()), | |
702 | Adjustment::Deref => Operand::Copy(tcx.mk_place_deref(rcvr_place())), | |
703 | Adjustment::DerefMove => Operand::Move(tcx.mk_place_deref(rcvr_place())), | |
cc61c64b XL |
704 | Adjustment::RefMut => { |
705 | // let rcvr = &mut rcvr; | |
706 | let ref_rcvr = local_decls.push(temp_decl( | |
707 | Mutability::Not, | |
dfeec247 XL |
708 | tcx.mk_ref( |
709 | tcx.lifetimes.re_erased, | |
710 | ty::TypeAndMut { ty: sig.inputs()[0], mutbl: hir::Mutability::Mut }, | |
711 | ), | |
712 | span, | |
cc61c64b | 713 | )); |
dfeec247 | 714 | let borrow_kind = BorrowKind::Mut { allow_two_phase_borrow: false }; |
cc61c64b | 715 | statements.push(Statement { |
3b2f2976 | 716 | source_info, |
dfeec247 XL |
717 | kind: StatementKind::Assign(box ( |
718 | Place::from(ref_rcvr), | |
719 | Rvalue::Ref(tcx.lifetimes.re_erased, borrow_kind, rcvr_place()), | |
720 | )), | |
cc61c64b | 721 | }); |
dc9dc135 | 722 | Operand::Move(Place::from(ref_rcvr)) |
cc61c64b | 723 | } |
dfeec247 | 724 | }); |
cc61c64b XL |
725 | |
726 | let (callee, mut args) = match call_kind { | |
dfeec247 | 727 | CallKind::Indirect => (rcvr.unwrap(), vec![]), |
ea8adc8c XL |
728 | CallKind::Direct(def_id) => { |
729 | let ty = tcx.type_of(def_id); | |
dfeec247 XL |
730 | ( |
731 | Operand::Constant(box Constant { | |
732 | span, | |
733 | user_ty: None, | |
734 | literal: ty::Const::zero_sized(tcx, ty), | |
735 | }), | |
736 | rcvr.into_iter().collect::<Vec<_>>(), | |
737 | ) | |
ea8adc8c | 738 | } |
cc61c64b XL |
739 | }; |
740 | ||
dfeec247 XL |
741 | let mut arg_range = 0..sig.inputs().len(); |
742 | ||
743 | // Take the `self` ("receiver") argument out of the range (it's adjusted above). | |
744 | if rcvr_adjustment.is_some() { | |
745 | arg_range.start += 1; | |
746 | } | |
747 | ||
748 | // Take the last argument, if we need to untuple it (handled below). | |
749 | if untuple_args.is_some() { | |
750 | arg_range.end -= 1; | |
751 | } | |
752 | ||
753 | // Pass all of the non-special arguments directly. | |
754 | args.extend(arg_range.map(|i| Operand::Move(Place::from(Local::new(1 + i))))); | |
755 | ||
756 | // Untuple the last argument, if we have to. | |
cc61c64b | 757 | if let Some(untuple_args) = untuple_args { |
dfeec247 | 758 | let tuple_arg = Local::new(1 + (sig.inputs().len() - 1)); |
cc61c64b | 759 | args.extend(untuple_args.iter().enumerate().map(|(i, ity)| { |
dfeec247 | 760 | Operand::Move(tcx.mk_place_field(Place::from(tuple_arg), Field::new(i), *ity)) |
cc61c64b XL |
761 | })); |
762 | } | |
763 | ||
dfeec247 | 764 | let n_blocks = if let Some(Adjustment::RefMut) = rcvr_adjustment { 5 } else { 2 }; |
a1dfa0c6 | 765 | let mut blocks = IndexVec::with_capacity(n_blocks); |
cc61c64b XL |
766 | let block = |blocks: &mut IndexVec<_, _>, statements, kind, is_cleanup| { |
767 | blocks.push(BasicBlockData { | |
768 | statements, | |
769 | terminator: Some(Terminator { source_info, kind }), | |
dfeec247 | 770 | is_cleanup, |
cc61c64b XL |
771 | }) |
772 | }; | |
773 | ||
774 | // BB #0 | |
dfeec247 XL |
775 | block( |
776 | &mut blocks, | |
777 | statements, | |
778 | TerminatorKind::Call { | |
779 | func: callee, | |
780 | args, | |
781 | destination: Some((Place::return_place(), BasicBlock::new(1))), | |
782 | cleanup: if let Some(Adjustment::RefMut) = rcvr_adjustment { | |
783 | Some(BasicBlock::new(3)) | |
784 | } else { | |
785 | None | |
786 | }, | |
787 | from_hir_call: true, | |
0bf4aa26 | 788 | }, |
dfeec247 XL |
789 | false, |
790 | ); | |
cc61c64b | 791 | |
dfeec247 | 792 | if let Some(Adjustment::RefMut) = rcvr_adjustment { |
cc61c64b | 793 | // BB #1 - drop for Self |
dfeec247 XL |
794 | block( |
795 | &mut blocks, | |
796 | vec![], | |
797 | TerminatorKind::Drop { | |
798 | location: rcvr_place(), | |
799 | target: BasicBlock::new(2), | |
800 | unwind: None, | |
801 | }, | |
802 | false, | |
803 | ); | |
cc61c64b XL |
804 | } |
805 | // BB #1/#2 - return | |
806 | block(&mut blocks, vec![], TerminatorKind::Return, false); | |
dfeec247 | 807 | if let Some(Adjustment::RefMut) = rcvr_adjustment { |
cc61c64b | 808 | // BB #3 - drop if closure panics |
dfeec247 XL |
809 | block( |
810 | &mut blocks, | |
811 | vec![], | |
812 | TerminatorKind::Drop { | |
813 | location: rcvr_place(), | |
814 | target: BasicBlock::new(4), | |
815 | unwind: None, | |
816 | }, | |
817 | true, | |
818 | ); | |
cc61c64b XL |
819 | |
820 | // BB #4 - resume | |
821 | block(&mut blocks, vec![], TerminatorKind::Resume, true); | |
822 | } | |
823 | ||
dfeec247 | 824 | let mut body = new_body(blocks, local_decls, sig.inputs().len(), span); |
60c5eb7d | 825 | |
cc61c64b | 826 | if let Abi::RustCall = sig.abi { |
dc9dc135 | 827 | body.spread_arg = Some(Local::new(sig.inputs().len())); |
cc61c64b | 828 | } |
60c5eb7d | 829 | BodyAndCache::new(body) |
cc61c64b XL |
830 | } |
831 | ||
60c5eb7d | 832 | pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> &BodyAndCache<'_> { |
dc9dc135 XL |
833 | debug_assert!(tcx.is_constructor(ctor_id)); |
834 | ||
dfeec247 XL |
835 | let span = |
836 | tcx.hir().span_if_local(ctor_id).unwrap_or_else(|| bug!("no span for ctor {:?}", ctor_id)); | |
dc9dc135 XL |
837 | |
838 | let param_env = tcx.param_env(ctor_id); | |
ff7c6d11 | 839 | |
0531ce1d | 840 | // Normalize the sig. |
dfeec247 | 841 | let sig = tcx.fn_sig(ctor_id).no_bound_vars().expect("LBR in ADT constructor signature"); |
dc9dc135 | 842 | let sig = tcx.normalize_erasing_regions(param_env, sig); |
cc61c64b | 843 | |
e74abb32 | 844 | let (adt_def, substs) = match sig.output().kind { |
b7449926 | 845 | ty::Adt(adt_def, substs) => (adt_def, substs), |
dfeec247 | 846 | _ => bug!("unexpected type for ADT ctor {:?}", sig.output()), |
cc61c64b XL |
847 | }; |
848 | ||
dc9dc135 | 849 | debug!("build_ctor: ctor_id={:?} sig={:?}", ctor_id, sig); |
cc61c64b XL |
850 | |
851 | let local_decls = local_decls_for_sig(&sig, span); | |
852 | ||
dfeec247 | 853 | let source_info = SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }; |
cc61c64b | 854 | |
dc9dc135 XL |
855 | let variant_index = if adt_def.is_enum() { |
856 | adt_def.variant_index_with_ctor_id(ctor_id) | |
cc61c64b | 857 | } else { |
a1dfa0c6 | 858 | VariantIdx::new(0) |
cc61c64b XL |
859 | }; |
860 | ||
dc9dc135 XL |
861 | // Generate the following MIR: |
862 | // | |
863 | // (return as Variant).field0 = arg0; | |
864 | // (return as Variant).field1 = arg1; | |
865 | // | |
866 | // return; | |
867 | debug!("build_ctor: variant_index={:?}", variant_index); | |
868 | ||
869 | let statements = expand_aggregate( | |
e1599b0c | 870 | Place::return_place(), |
dfeec247 XL |
871 | adt_def.variants[variant_index].fields.iter().enumerate().map(|(idx, field_def)| { |
872 | (Operand::Move(Place::from(Local::new(idx + 1))), field_def.ty(tcx, substs)) | |
873 | }), | |
dc9dc135 XL |
874 | AggregateKind::Adt(adt_def, variant_index, substs, None, None), |
875 | source_info, | |
e74abb32 | 876 | tcx, |
dfeec247 XL |
877 | ) |
878 | .collect(); | |
dc9dc135 | 879 | |
cc61c64b | 880 | let start_block = BasicBlockData { |
dc9dc135 | 881 | statements, |
dfeec247 XL |
882 | terminator: Some(Terminator { source_info, kind: TerminatorKind::Return }), |
883 | is_cleanup: false, | |
cc61c64b XL |
884 | }; |
885 | ||
dfeec247 XL |
886 | let body = |
887 | new_body(IndexVec::from_elem_n(start_block, 1), local_decls, sig.inputs().len(), span); | |
dc9dc135 XL |
888 | |
889 | crate::util::dump_mir( | |
890 | tcx, | |
891 | None, | |
892 | "mir_map", | |
893 | &0, | |
894 | crate::transform::MirSource::item(ctor_id), | |
895 | &body, | |
896 | |_, _| Ok(()), | |
897 | ); | |
898 | ||
60c5eb7d XL |
899 | let mut body = BodyAndCache::new(body); |
900 | body.ensure_predecessors(); | |
dc9dc135 | 901 | tcx.arena.alloc(body) |
cc61c64b | 902 | } |