1 use crate::{shim, util}
;
2 use rustc
::hir
::map
::Map
;
3 use rustc
::mir
::{BodyAndCache, ConstQualifs, MirPhase, Promoted}
;
4 use rustc
::ty
::query
::Providers
;
5 use rustc
::ty
::steal
::Steal
;
6 use rustc
::ty
::{InstanceDef, TyCtxt, TypeFoldable}
;
9 use rustc_hir
::def_id
::{CrateNum, DefId, DefIdSet, LOCAL_CRATE}
;
10 use rustc_hir
::intravisit
::{self, NestedVisitorMap, Visitor}
;
11 use rustc_index
::vec
::IndexVec
;
15 pub mod add_call_guards
;
16 pub mod add_moves_for_packed_drops
;
19 pub mod check_unsafety
;
20 pub mod cleanup_post_borrowck
;
25 pub mod elaborate_drops
;
26 pub mod erase_regions
;
30 pub mod no_landing_pads
;
31 pub mod promote_consts
;
32 pub mod qualify_min_const_fn
;
33 pub mod remove_noop_landing_pads
;
36 pub mod simplify_branches
;
38 pub mod uninhabited_enum_branching
;
39 pub mod unreachable_prop
;
41 pub(crate) fn provide(providers
: &mut Providers
<'_
>) {
42 self::check_unsafety
::provide(providers
);
43 *providers
= Providers
{
55 fn is_mir_available(tcx
: TyCtxt
<'_
>, def_id
: DefId
) -> bool
{
56 tcx
.mir_keys(def_id
.krate
).contains(&def_id
)
59 /// Finds the full set of `DefId`s within the current crate that have
60 /// MIR associated with them.
61 fn mir_keys(tcx
: TyCtxt
<'_
>, krate
: CrateNum
) -> &DefIdSet
{
62 assert_eq
!(krate
, LOCAL_CRATE
);
64 let mut set
= DefIdSet
::default();
66 // All body-owners have MIR associated with them.
67 set
.extend(tcx
.body_owners());
69 // Additionally, tuple struct/variant constructors have MIR, but
70 // they don't have a BodyId, so we need to build them separately.
71 struct GatherCtors
<'a
, 'tcx
> {
73 set
: &'a
mut DefIdSet
,
75 impl<'a
, 'tcx
> Visitor
<'tcx
> for GatherCtors
<'a
, 'tcx
> {
76 fn visit_variant_data(
78 v
: &'tcx hir
::VariantData
<'tcx
>,
80 _
: &'tcx hir
::Generics
<'tcx
>,
84 if let hir
::VariantData
::Tuple(_
, hir_id
) = *v
{
85 self.set
.insert(self.tcx
.hir().local_def_id(hir_id
));
87 intravisit
::walk_struct_def(self, v
)
90 fn nested_visit_map
<'b
>(&'b
mut self) -> NestedVisitorMap
<'b
, Self::Map
> {
91 NestedVisitorMap
::None
96 .visit_all_item_likes(&mut GatherCtors { tcx, set: &mut set }
.as_deep_visitor());
101 /// Where a specific `mir::Body` comes from.
102 #[derive(Debug, Copy, Clone)]
103 pub struct MirSource
<'tcx
> {
104 pub instance
: InstanceDef
<'tcx
>,
106 /// If `Some`, this is a promoted rvalue within the parent function.
107 pub promoted
: Option
<Promoted
>,
110 impl<'tcx
> MirSource
<'tcx
> {
111 pub fn item(def_id
: DefId
) -> Self {
112 MirSource { instance: InstanceDef::Item(def_id), promoted: None }
116 pub fn def_id(&self) -> DefId
{
117 self.instance
.def_id()
121 /// Generates a default name for the pass based on the name of the
123 pub fn default_name
<T
: ?Sized
>() -> Cow
<'
static, str> {
124 let name
= ::std
::any
::type_name
::<T
>();
125 if let Some(tail
) = name
.rfind('
:'
) { Cow::from(&name[tail + 1..]) }
else { Cow::from(name) }
128 /// A streamlined trait that you can implement to create a pass; the
129 /// pass will be named after the type, and it will consist of a main
130 /// loop that goes over each available MIR and applies `run_pass`.
131 pub trait MirPass
<'tcx
> {
132 fn name(&self) -> Cow
<'_
, str> {
133 default_name
::<Self>()
136 fn run_pass(&self, tcx
: TyCtxt
<'tcx
>, source
: MirSource
<'tcx
>, body
: &mut BodyAndCache
<'tcx
>);
141 body
: &mut BodyAndCache
<'tcx
>,
142 instance
: InstanceDef
<'tcx
>,
143 promoted
: Option
<Promoted
>,
145 passes
: &[&dyn MirPass
<'tcx
>],
147 let phase_index
= mir_phase
.phase_index();
149 if body
.phase
>= mir_phase
{
153 let source
= MirSource { instance, promoted }
;
155 let mut run_pass
= |pass
: &dyn MirPass
<'tcx
>| {
156 let run_hooks
= |body
: &_
, index
, is_after
| {
157 dump_mir
::on_mir_pass(
159 &format_args
!("{:03}-{:03}", phase_index
, index
),
166 run_hooks(body
, index
, false);
167 pass
.run_pass(tcx
, source
, body
);
168 run_hooks(body
, index
, true);
177 body
.phase
= mir_phase
;
180 fn mir_const_qualif(tcx
: TyCtxt
<'_
>, def_id
: DefId
) -> ConstQualifs
{
181 let const_kind
= check_consts
::ConstKind
::for_item(tcx
, def_id
);
183 // No need to const-check a non-const `fn`.
184 if const_kind
.is_none() {
185 return Default
::default();
188 // N.B., this `borrow()` is guaranteed to be valid (i.e., the value
189 // cannot yet be stolen), because `mir_validated()`, which steals
190 // from `mir_const(), forces this query to execute before
191 // performing the steal.
192 let body
= &tcx
.mir_const(def_id
).borrow();
194 if body
.return_ty().references_error() {
195 tcx
.sess
.delay_span_bug(body
.span
, "mir_const_qualif: MIR had errors");
196 return Default
::default();
199 let item
= check_consts
::Item
{
200 body
: body
.unwrap_read_only(),
204 param_env
: tcx
.param_env(def_id
),
207 let mut validator
= check_consts
::validation
::Validator
::new(&item
);
208 validator
.check_body();
210 // We return the qualifs in the return place for every MIR body, even though it is only used
211 // when deciding to promote a reference to a `const` for now.
212 validator
.qualifs_in_return_place()
215 fn mir_const(tcx
: TyCtxt
<'_
>, def_id
: DefId
) -> &Steal
<BodyAndCache
<'_
>> {
216 // Unsafety check uses the raw mir, so make sure it is run
217 let _
= tcx
.unsafety_check_result(def_id
);
219 let mut body
= tcx
.mir_built(def_id
).steal();
221 util
::dump_mir(tcx
, None
, "mir_map", &0, MirSource
::item(def_id
), &body
, |_
, _
| Ok(()));
226 InstanceDef
::Item(def_id
),
230 // What we need to do constant evaluation.
231 &simplify
::SimplifyCfg
::new("initial"),
232 &rustc_peek
::SanityCheck
,
235 body
.ensure_predecessors();
236 tcx
.alloc_steal_mir(body
)
242 ) -> (&'tcx Steal
<BodyAndCache
<'tcx
>>, &'tcx Steal
<IndexVec
<Promoted
, BodyAndCache
<'tcx
>>>) {
243 // Ensure that we compute the `mir_const_qualif` for constants at
244 // this point, before we steal the mir-const result.
245 let _
= tcx
.mir_const_qualif(def_id
);
247 let mut body
= tcx
.mir_const(def_id
).steal();
248 let promote_pass
= promote_consts
::PromoteTemps
::default();
252 InstanceDef
::Item(def_id
),
256 // What we need to run borrowck etc.
258 &simplify
::SimplifyCfg
::new("qualify-consts"),
262 let promoted
= promote_pass
.promoted_fragments
.into_inner();
263 (tcx
.alloc_steal_mir(body
), tcx
.alloc_steal_promoted(promoted
))
266 fn run_optimization_passes
<'tcx
>(
268 body
: &mut BodyAndCache
<'tcx
>,
270 promoted
: Option
<Promoted
>,
275 InstanceDef
::Item(def_id
),
279 // Remove all things only needed by analysis
280 &no_landing_pads
::NoLandingPads
::new(tcx
),
281 &simplify_branches
::SimplifyBranches
::new("initial"),
282 &remove_noop_landing_pads
::RemoveNoopLandingPads
,
283 &cleanup_post_borrowck
::CleanupNonCodegenStatements
,
284 &simplify
::SimplifyCfg
::new("early-opt"),
285 // These next passes must be executed together
286 &add_call_guards
::CriticalCallEdges
,
287 &elaborate_drops
::ElaborateDrops
,
288 &no_landing_pads
::NoLandingPads
::new(tcx
),
289 // AddMovesForPackedDrops needs to run after drop
291 &add_moves_for_packed_drops
::AddMovesForPackedDrops
,
292 // AddRetag needs to run after ElaborateDrops, and it needs
293 // an AllCallEdges pass right before it. Otherwise it should
294 // run fairly late, but before optimizations begin.
295 &add_call_guards
::AllCallEdges
,
296 &add_retag
::AddRetag
,
297 &simplify
::SimplifyCfg
::new("elaborate-drops"),
298 // No lifetime analysis based on borrowing can be done from here on out.
300 // From here on out, regions are gone.
301 &erase_regions
::EraseRegions
,
302 // Optimizations begin.
303 &unreachable_prop
::UnreachablePropagation
,
304 &uninhabited_enum_branching
::UninhabitedEnumBranching
,
305 &simplify
::SimplifyCfg
::new("after-uninhabited-enum-branching"),
307 // Lowering generator control-flow and variables
308 // has to happen before we do anything else to them.
309 &generator
::StateTransform
,
310 &instcombine
::InstCombine
,
311 &const_prop
::ConstProp
,
312 &simplify_branches
::SimplifyBranches
::new("after-const-prop"),
313 &deaggregator
::Deaggregator
,
314 ©_prop
::CopyPropagation
,
315 &simplify_branches
::SimplifyBranches
::new("after-copy-prop"),
316 &remove_noop_landing_pads
::RemoveNoopLandingPads
,
317 &simplify
::SimplifyCfg
::new("after-remove-noop-landing-pads"),
318 &simplify_try
::SimplifyArmIdentity
,
319 &simplify_try
::SimplifyBranchSame
,
320 &simplify
::SimplifyCfg
::new("final"),
321 &simplify
::SimplifyLocals
,
322 &add_call_guards
::CriticalCallEdges
,
323 &dump_mir
::Marker("PreCodegen"),
328 fn optimized_mir(tcx
: TyCtxt
<'_
>, def_id
: DefId
) -> &BodyAndCache
<'_
> {
329 if tcx
.is_constructor(def_id
) {
330 // There's no reason to run all of the MIR passes on constructors when
331 // we can just output the MIR we want directly. This also saves const
332 // qualification and borrow checking the trouble of special casing
334 return shim
::build_adt_ctor(tcx
, def_id
);
337 // (Mir-)Borrowck uses `mir_validated`, so we have to force it to
338 // execute before we can steal.
339 tcx
.ensure().mir_borrowck(def_id
);
341 let (body
, _
) = tcx
.mir_validated(def_id
);
342 let mut body
= body
.steal();
343 run_optimization_passes(tcx
, &mut body
, def_id
, None
);
344 body
.ensure_predecessors();
345 tcx
.arena
.alloc(body
)
348 fn promoted_mir(tcx
: TyCtxt
<'_
>, def_id
: DefId
) -> &IndexVec
<Promoted
, BodyAndCache
<'_
>> {
349 if tcx
.is_constructor(def_id
) {
350 return tcx
.intern_promoted(IndexVec
::new());
353 tcx
.ensure().mir_borrowck(def_id
);
354 let (_
, promoted
) = tcx
.mir_validated(def_id
);
355 let mut promoted
= promoted
.steal();
357 for (p
, mut body
) in promoted
.iter_enumerated_mut() {
358 run_optimization_passes(tcx
, &mut body
, def_id
, Some(p
));
359 body
.ensure_predecessors();
362 tcx
.intern_promoted(promoted
)