hir_ty/
lib.rs

1//! The type system. We currently use this to infer types for completion, hover
2//! information and various assists.
3
4#![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
5// It's useful to refer to code that is private in doc comments.
6#![allow(rustdoc::private_intra_doc_links)]
7
8// FIXME: We used to import `rustc_*` deps from `rustc_private` with `feature = "in-rust-tree" but
9// temporarily switched to crates.io versions due to hardships that working on them from rustc
10// demands corresponding changes on rust-analyzer at the same time.
11// For details, see the zulip discussion below:
12// https://rust-lang.zulipchat.com/#narrow/channel/185405-t-compiler.2Frust-analyzer/topic/relying.20on.20in-tree.20.60rustc_type_ir.60.2F.60rustc_next_trait_solver.60/with/541055689
13
14extern crate ra_ap_rustc_index as rustc_index;
15
16extern crate ra_ap_rustc_abi as rustc_abi;
17
18extern crate ra_ap_rustc_pattern_analysis as rustc_pattern_analysis;
19
20extern crate ra_ap_rustc_ast_ir as rustc_ast_ir;
21
22extern crate ra_ap_rustc_type_ir as rustc_type_ir;
23
24extern crate ra_ap_rustc_next_trait_solver as rustc_next_trait_solver;
25
26extern crate self as hir_ty;
27
28pub mod builtin_derive;
29mod generics;
30mod infer;
31mod inhabitedness;
32mod lower;
33pub mod next_solver;
34mod opaques;
35mod representability;
36mod specialization;
37mod target_feature;
38mod utils;
39mod variance;
40
41pub mod autoderef;
42pub mod consteval;
43pub mod db;
44pub mod diagnostics;
45pub mod display;
46pub mod drop;
47pub mod dyn_compatibility;
48pub mod lang_items;
49pub mod layout;
50pub mod method_resolution;
51pub mod mir;
52pub mod primitive;
53pub mod solver_errors;
54pub mod traits;
55pub mod upvars;
56
57#[cfg(test)]
58mod test_db;
59#[cfg(test)]
60mod tests;
61
62use std::{hash::Hash, ops::ControlFlow};
63
64use base_db::SourceDatabase;
65use hir_def::{
66    CallableDefId, ConstId, DefWithBodyId, EnumVariantId, ExpressionStoreOwnerId, FunctionId,
67    GenericDefId, HasModule, LifetimeParamId, ModuleId, StaticId, TypeAliasId, TypeOrConstParamId,
68    TypeParamId,
69    expr_store::{Body, ExpressionStore},
70    hir::{BindingId, ExprId, ExprOrPatId, ExprOrPatIdPacked, PatId},
71    resolver::{HasResolver, Resolver, TypeNs},
72    type_ref::{Rawness, TypeRefId},
73};
74use hir_expand::name::Name;
75use indexmap::{IndexMap, map::Entry};
76use macros::GenericTypeVisitable;
77use mir::{MirEvalError, VTableMap};
78use rustc_abi::ExternAbi;
79use rustc_hash::{FxBuildHasher, FxHashMap, FxHashSet};
80use rustc_type_ir::{
81    BoundVarIndexKind, TypeSuperVisitable, TypeVisitableExt,
82    inherent::{IntoKind, Ty as _},
83};
84use salsa::Update;
85use stdx::impl_from;
86use syntax::ast::{ConstArg, make};
87use traits::FnTrait;
88
89use crate::{
90    db::{AnonConstId, HirDatabase},
91    display::HirDisplay,
92    lower::SupertraitsInfo,
93    next_solver::{
94        AliasTy, Binder, BoundConst, BoundRegion, BoundRegionKind, BoundTy, BoundTyKind, Canonical,
95        CanonicalVarKind, CanonicalVarKinds, ClauseKind, Const, ConstKind, DbInterner, GenericArgs,
96        PolyFnSig, Region, RegionKind, TraitRef, Ty, TyKind, TypingMode,
97        abi::Safety,
98        infer::{
99            DbInternerInferExt,
100            traits::{Obligation, ObligationCause},
101        },
102        obligation_ctxt::ObligationCtxt,
103    },
104};
105
106pub use autoderef::autoderef;
107pub use infer::{
108    Adjust, Adjustment, AutoBorrow, BindingMode, ByRef, ExplicitDropMethodUseKind,
109    InferenceDiagnostic, InferenceResult, InferenceTyDiagnosticSource, OverloadedDeref,
110    PointerCast, ReturnKind, cast::CastError, could_coerce, could_unify, could_unify_deeply,
111    infer_query_with_inspect,
112};
113pub use lower::{
114    FieldType, GenericDefaults, GenericDefaultsRef, GenericPredicates, ImplTraits,
115    LifetimeElisionKind, LifetimeLoweringMode, LoweringMode, TyDefId, TyLoweringContext,
116    TyLoweringInferVarsCtx, TyLoweringResult, ValueTyDefId, diagnostics::*,
117};
118pub use next_solver::interner::{attach_db, attach_db_allow_change, with_attached_db};
119pub use target_feature::TargetFeatures;
120pub use traits::{ParamEnvAndCrate, check_orphan_rules};
121pub use utils::{
122    TargetFeatureIsSafeInTarget, Unsafety, all_super_traits, direct_super_traits,
123    is_fn_unsafe_to_call, target_feature_is_safe_in_target,
124};
125
126pub mod closure_analysis {
127    pub use crate::infer::{
128        CaptureInfo, CaptureSourceStack, CapturedPlace, ClosureData, UpvarCapture,
129        closure::analysis::{
130            BorrowKind,
131            expr_use_visitor::{FakeReadCause, Place, PlaceBase, Projection, ProjectionKind},
132        },
133    };
134}
135
136/// A constant can have reference to other things. Memory map job is holding
137/// the necessary bits of memory of the const eval session to keep the constant
138/// meaningful.
139#[derive(Debug, Default, Clone, PartialEq, Eq, GenericTypeVisitable)]
140pub enum MemoryMap<'db> {
141    #[default]
142    Empty,
143    Simple(Box<[u8]>),
144    Complex(Box<ComplexMemoryMap<'db>>),
145}
146
147#[derive(Debug, Default, Clone, PartialEq, Eq, GenericTypeVisitable)]
148pub struct ComplexMemoryMap<'db> {
149    memory: IndexMap<usize, Box<[u8]>, FxBuildHasher>,
150    vtable: VTableMap<'db>,
151}
152
153impl ComplexMemoryMap<'_> {
154    fn insert(&mut self, addr: usize, val: Box<[u8]>) {
155        match self.memory.entry(addr) {
156            Entry::Occupied(mut e) => {
157                if e.get().len() < val.len() {
158                    e.insert(val);
159                }
160            }
161            Entry::Vacant(e) => {
162                e.insert(val);
163            }
164        }
165    }
166}
167
168impl<'db> MemoryMap<'db> {
169    pub fn vtable_ty(&self, id: usize) -> Result<Ty<'db>, MirEvalError<'db>> {
170        match self {
171            MemoryMap::Empty | MemoryMap::Simple(_) => Err(MirEvalError::InvalidVTableId(id)),
172            MemoryMap::Complex(cm) => cm.vtable.ty(id),
173        }
174    }
175
176    fn simple(v: Box<[u8]>) -> Self {
177        MemoryMap::Simple(v)
178    }
179
180    /// This functions convert each address by a function `f` which gets the byte intervals and assign an address
181    /// to them. It is useful when you want to load a constant with a memory map in a new memory. You can pass an
182    /// allocator function as `f` and it will return a mapping of old addresses to new addresses.
183    fn transform_addresses(
184        &self,
185        mut f: impl FnMut(&[u8], usize) -> Result<usize, MirEvalError<'db>>,
186    ) -> Result<FxHashMap<usize, usize>, MirEvalError<'db>> {
187        let mut transform = |(addr, val): (&usize, &[u8])| {
188            let addr = *addr;
189            let align = if addr == 0 { 64 } else { (addr - (addr & (addr - 1))).min(64) };
190            f(val, align).map(|it| (addr, it))
191        };
192        match self {
193            MemoryMap::Empty => Ok(Default::default()),
194            MemoryMap::Simple(m) => transform((&0, m)).map(|(addr, val)| {
195                let mut map = FxHashMap::with_capacity_and_hasher(1, rustc_hash::FxBuildHasher);
196                map.insert(addr, val);
197                map
198            }),
199            MemoryMap::Complex(cm) => {
200                cm.memory.iter().map(|(addr, val)| transform((addr, val))).collect()
201            }
202        }
203    }
204
205    fn get(&self, addr: usize, size: usize) -> Option<&[u8]> {
206        if size == 0 {
207            Some(&[])
208        } else {
209            match self {
210                MemoryMap::Empty => Some(&[]),
211                MemoryMap::Simple(m) if addr == 0 => m.get(0..size),
212                MemoryMap::Simple(_) => None,
213                MemoryMap::Complex(cm) => cm.memory.get(&addr)?.get(0..size),
214            }
215        }
216    }
217}
218
219/// Return an index of a parameter in the generic type parameter list by it's id.
220pub fn type_or_const_param_idx(db: &dyn HirDatabase, id: TypeOrConstParamId) -> u32 {
221    generics::generics(db, id.parent).type_or_const_param_idx(id)
222}
223
224pub fn lifetime_param_idx(db: &dyn HirDatabase, id: LifetimeParamId) -> u32 {
225    generics::generics(db, id.parent).lifetime_param_idx(id, false).0
226}
227
228#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
229pub enum ImplTraitId {
230    ReturnTypeImplTrait(hir_def::FunctionId, next_solver::ImplTraitIdx),
231    TypeAliasImplTrait(hir_def::TypeAliasId, next_solver::ImplTraitIdx),
232}
233
234/// 'Canonicalizes' the `t` by replacing any errors with new variables. Also
235/// ensures there are no unbound variables or inference variables anywhere in
236/// the `t`.
237pub fn replace_errors_with_variables<'db, T>(interner: DbInterner<'db>, t: &T) -> Canonical<'db, T>
238where
239    T: rustc_type_ir::TypeFoldable<DbInterner<'db>> + Clone,
240{
241    use rustc_type_ir::{FallibleTypeFolder, TypeSuperFoldable};
242    struct ErrorReplacer<'db> {
243        interner: DbInterner<'db>,
244        vars: Vec<CanonicalVarKind<'db>>,
245        binder: rustc_type_ir::DebruijnIndex,
246    }
247    impl<'db> FallibleTypeFolder<DbInterner<'db>> for ErrorReplacer<'db> {
248        #[cfg(debug_assertions)]
249        type Error = ();
250        #[cfg(not(debug_assertions))]
251        type Error = std::convert::Infallible;
252
253        fn cx(&self) -> DbInterner<'db> {
254            self.interner
255        }
256
257        fn try_fold_binder<T>(&mut self, t: Binder<'db, T>) -> Result<Binder<'db, T>, Self::Error>
258        where
259            T: rustc_type_ir::TypeFoldable<DbInterner<'db>>,
260        {
261            self.binder.shift_in(1);
262            let result = t.try_super_fold_with(self);
263            self.binder.shift_out(1);
264            result
265        }
266
267        fn try_fold_ty(&mut self, t: Ty<'db>) -> Result<Ty<'db>, Self::Error> {
268            if !t.has_type_flags(
269                rustc_type_ir::TypeFlags::HAS_ERROR
270                    | rustc_type_ir::TypeFlags::HAS_TY_INFER
271                    | rustc_type_ir::TypeFlags::HAS_CT_INFER
272                    | rustc_type_ir::TypeFlags::HAS_RE_INFER,
273            ) {
274                return Ok(t);
275            }
276
277            #[cfg(debug_assertions)]
278            let error = || Err(());
279            #[cfg(not(debug_assertions))]
280            let error = || Ok(Ty::new_error(self.interner, crate::next_solver::ErrorGuaranteed));
281
282            match t.kind() {
283                TyKind::Error(_) => {
284                    let var = rustc_type_ir::BoundVar::from_usize(self.vars.len());
285                    self.vars.push(CanonicalVarKind::Ty {
286                        ui: rustc_type_ir::UniverseIndex::ZERO,
287                        sub_root: var,
288                    });
289                    Ok(Ty::new_bound(
290                        self.interner,
291                        self.binder,
292                        BoundTy { var, kind: BoundTyKind::Anon },
293                    ))
294                }
295                TyKind::Infer(_) => error(),
296                TyKind::Bound(BoundVarIndexKind::Bound(index), _) if index > self.binder => error(),
297                _ => t.try_super_fold_with(self),
298            }
299        }
300
301        fn try_fold_const(&mut self, ct: Const<'db>) -> Result<Const<'db>, Self::Error> {
302            if !ct.has_type_flags(
303                rustc_type_ir::TypeFlags::HAS_ERROR
304                    | rustc_type_ir::TypeFlags::HAS_TY_INFER
305                    | rustc_type_ir::TypeFlags::HAS_CT_INFER
306                    | rustc_type_ir::TypeFlags::HAS_RE_INFER,
307            ) {
308                return Ok(ct);
309            }
310
311            #[cfg(debug_assertions)]
312            let error = || Err(());
313            #[cfg(not(debug_assertions))]
314            let error = || Ok(Const::error(self.interner));
315
316            match ct.kind() {
317                ConstKind::Error(_) => {
318                    let var = rustc_type_ir::BoundVar::from_usize(self.vars.len());
319                    self.vars.push(CanonicalVarKind::Const(rustc_type_ir::UniverseIndex::ZERO));
320                    Ok(Const::new_bound(self.interner, self.binder, BoundConst::new(var)))
321                }
322                ConstKind::Infer(_) => error(),
323                ConstKind::Bound(BoundVarIndexKind::Bound(index), _) if index > self.binder => {
324                    error()
325                }
326                _ => ct.try_super_fold_with(self),
327            }
328        }
329
330        fn try_fold_region(&mut self, region: Region<'db>) -> Result<Region<'db>, Self::Error> {
331            #[cfg(debug_assertions)]
332            let error = || Err(());
333            #[cfg(not(debug_assertions))]
334            let error = || Ok(Region::error(self.interner));
335
336            match region.kind() {
337                RegionKind::ReError(_) => {
338                    let var = rustc_type_ir::BoundVar::from_usize(self.vars.len());
339                    self.vars.push(CanonicalVarKind::Region(rustc_type_ir::UniverseIndex::ZERO));
340                    Ok(Region::new_bound(
341                        self.interner,
342                        self.binder,
343                        BoundRegion { var, kind: BoundRegionKind::Anon },
344                    ))
345                }
346                RegionKind::ReVar(_) => error(),
347                RegionKind::ReBound(BoundVarIndexKind::Bound(index), _) if index > self.binder => {
348                    error()
349                }
350                _ => Ok(region),
351            }
352        }
353    }
354
355    let mut error_replacer =
356        ErrorReplacer { vars: Vec::new(), binder: rustc_type_ir::DebruijnIndex::ZERO, interner };
357    let value = match t.clone().try_fold_with(&mut error_replacer) {
358        Ok(t) => t,
359        Err(_) => panic!("Encountered unbound or inference vars in {t:?}"),
360    };
361    Canonical {
362        value,
363        max_universe: rustc_type_ir::UniverseIndex::ZERO,
364        var_kinds: CanonicalVarKinds::new_from_slice(&error_replacer.vars),
365    }
366}
367
368/// To be used from `hir` only.
369pub fn associated_type_shorthand_candidates(
370    db: &dyn HirDatabase,
371    def: GenericDefId,
372    res: TypeNs,
373    mut cb: impl FnMut(&Name, TypeAliasId) -> bool,
374) -> Option<TypeAliasId> {
375    let interner = DbInterner::new_no_crate(db);
376    let (def, param) = match res {
377        TypeNs::GenericParam(param) => (def, param),
378        TypeNs::SelfType(impl_) => {
379            let impl_trait = db.impl_trait(impl_)?.skip_binder().def_id.0;
380            let param = TypeParamId::trait_self(impl_trait);
381            (impl_trait.into(), param)
382        }
383        _ => return None,
384    };
385
386    let mut dedup_map = FxHashSet::default();
387    let param_ty = Ty::new_param(interner, param, type_or_const_param_idx(db, param.into()));
388    // We use the ParamEnv and not the predicates because the ParamEnv elaborates bounds.
389    let param_env = db.trait_environment(def);
390    for clause in param_env.clauses {
391        let ClauseKind::Trait(trait_clause) = clause.kind().skip_binder() else { continue };
392        if trait_clause.self_ty() != param_ty {
393            continue;
394        }
395        let trait_id = trait_clause.def_id().0;
396        dedup_map.extend(
397            SupertraitsInfo::query(db, trait_id)
398                .defined_assoc_types
399                .iter()
400                .map(|(name, id)| (name, *id)),
401        );
402    }
403
404    dedup_map
405        .into_iter()
406        .try_for_each(
407            |(name, id)| {
408                if cb(name, id) { ControlFlow::Break(id) } else { ControlFlow::Continue(()) }
409            },
410        )
411        .break_value()
412}
413
414/// To be used from `hir` only.
415pub fn callable_sig_from_fn_trait<'db>(
416    self_ty: Ty<'db>,
417    param_env: ParamEnvAndCrate<'db>,
418    db: &'db dyn HirDatabase,
419) -> Option<(FnTrait, PolyFnSig<'db>)> {
420    let ParamEnvAndCrate { param_env, krate } = param_env;
421    let interner = DbInterner::new_with(db, krate);
422    let infcx = interner.infer_ctxt().build(TypingMode::PostAnalysis);
423    let lang_items = interner.lang_items();
424    let cause = ObligationCause::dummy();
425
426    let impls_trait = |trait_: FnTrait| {
427        let mut ocx = ObligationCtxt::new(&infcx);
428        let tupled_args = infcx.next_ty_var(Span::Dummy);
429        let args = GenericArgs::new_from_slice(&[self_ty.into(), tupled_args.into()]);
430        let trait_id = trait_.get_id(lang_items)?;
431        let trait_ref = TraitRef::new_from_args(interner, trait_id.into(), args);
432        let obligation = Obligation::new(interner, cause, param_env, trait_ref);
433        ocx.register_obligation(obligation);
434        if !ocx.try_evaluate_obligations().is_empty() {
435            return None;
436        }
437        let tupled_args =
438            infcx.resolve_vars_if_possible(tupled_args).replace_infer_with_error(interner);
439        if tupled_args.is_tuple() { Some(tupled_args) } else { None }
440    };
441
442    let (trait_, args) = 'find_trait: {
443        for trait_ in [FnTrait::Fn, FnTrait::FnMut, FnTrait::FnOnce] {
444            if let Some(args) = impls_trait(trait_) {
445                break 'find_trait (trait_, args);
446            }
447        }
448        return None;
449    };
450
451    let output_assoc_type = lang_items.FnOnceOutput?;
452    let output_projection = Ty::new_alias(
453        interner,
454        AliasTy::new(
455            interner,
456            rustc_type_ir::Projection { def_id: output_assoc_type.into() },
457            [self_ty, args],
458        ),
459    );
460    let mut ocx = ObligationCtxt::new(&infcx);
461    let ret = ocx.structurally_normalize_ty(&cause, param_env, output_projection).ok()?;
462    let ret = ret.replace_infer_with_error(interner);
463
464    let sig = Binder::dummy(interner.mk_fn_sig(
465        args.tuple_fields(),
466        ret,
467        false,
468        // FIXME(splat): handle splatted arguments
469        Safety::Safe,
470        ExternAbi::Rust,
471    ));
472    Some((trait_, sig))
473}
474
475struct ParamCollector {
476    params: FxHashSet<TypeOrConstParamId>,
477}
478
479impl<'db> rustc_type_ir::TypeVisitor<DbInterner<'db>> for ParamCollector {
480    type Result = ();
481
482    fn visit_ty(&mut self, ty: Ty<'db>) -> Self::Result {
483        if let TyKind::Param(param) = ty.kind() {
484            self.params.insert(param.id.into());
485        }
486
487        ty.super_visit_with(self);
488    }
489
490    fn visit_const(&mut self, konst: Const<'db>) -> Self::Result {
491        if let ConstKind::Param(param) = konst.kind() {
492            self.params.insert(param.id.into());
493        }
494
495        konst.super_visit_with(self);
496    }
497}
498
499/// Returns unique params for types and consts contained in `value`.
500pub fn collect_params<'db, T>(value: &T) -> Vec<TypeOrConstParamId>
501where
502    T: ?Sized + rustc_type_ir::TypeVisitable<DbInterner<'db>>,
503{
504    let mut collector = ParamCollector { params: FxHashSet::default() };
505    value.visit_with(&mut collector);
506    Vec::from_iter(collector.params)
507}
508
509pub fn known_const_to_ast<'db>(
510    konst: Const<'db>,
511    db: &'db dyn HirDatabase,
512    target_module: ModuleId,
513) -> Option<ConstArg> {
514    Some(make::expr_const_value(
515        &konst.display_source_code(db, target_module, true).unwrap_or_else(|_| "_".to_owned()),
516    ))
517}
518
519/// A `Span` represents some location in lowered code - a type, expression or pattern.
520///
521/// It has no meaning outside its body therefore it should not exit the pass it was created in
522/// (e.g. inference). It is usually associated with a solver obligation or an infer var, which
523/// should also not cross the pass they were created in.
524#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
525pub enum Span {
526    ExprId(ExprId),
527    PatId(PatId),
528    BindingId(BindingId),
529    TypeRefId(TypeRefId),
530    /// An unimportant location. Errors on this will be suppressed.
531    Dummy,
532}
533impl_from!(ExprId, PatId, BindingId, TypeRefId for Span);
534
535impl From<ExprOrPatIdPacked> for Span {
536    fn from(value: ExprOrPatIdPacked) -> Self {
537        match value.unpack() {
538            ExprOrPatId::ExprId(idx) => idx.into(),
539            ExprOrPatId::PatId(idx) => idx.into(),
540        }
541    }
542}
543
544impl Span {
545    pub(crate) fn pick_best(a: Span, b: Span) -> Span {
546        // We prefer dummy spans to minimize the risk of false errors.
547        if b.is_dummy() { b } else { a }
548    }
549
550    #[inline]
551    pub fn is_dummy(&self) -> bool {
552        matches!(self, Self::Dummy)
553    }
554}
555
556/// A [`DefWithBodyId`], or an anon const.
557#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, salsa::Supertype, Update)]
558pub enum InferBodyId<'db> {
559    DefWithBodyId(DefWithBodyId),
560    AnonConstId(AnonConstId<'db>),
561}
562impl_from!(
563    impl<'db>
564    DefWithBodyId(FunctionId, ConstId, StaticId),
565    AnonConstId<'db>
566    for InferBodyId<'db>
567);
568impl<'db> From<EnumVariantId> for InferBodyId<'db> {
569    fn from(id: EnumVariantId) -> Self {
570        InferBodyId::DefWithBodyId(DefWithBodyId::VariantId(id))
571    }
572}
573
574impl HasModule for InferBodyId<'_> {
575    fn module(&self, db: &dyn SourceDatabase) -> ModuleId {
576        match self {
577            InferBodyId::DefWithBodyId(id) => id.module(db),
578            InferBodyId::AnonConstId(id) => id.module(db),
579        }
580    }
581}
582
583impl HasResolver for InferBodyId<'_> {
584    fn resolver(self, db: &dyn SourceDatabase) -> Resolver<'_> {
585        match self {
586            InferBodyId::DefWithBodyId(id) => id.resolver(db),
587            InferBodyId::AnonConstId(id) => id.resolver(db),
588        }
589    }
590}
591
592impl InferBodyId<'_> {
593    pub fn expression_store_owner(self, db: &dyn HirDatabase) -> ExpressionStoreOwnerId {
594        match self {
595            InferBodyId::DefWithBodyId(id) => id.into(),
596            InferBodyId::AnonConstId(id) => id.loc(db).owner,
597        }
598    }
599
600    pub fn generic_def(self, db: &dyn HirDatabase) -> GenericDefId {
601        match self {
602            InferBodyId::DefWithBodyId(id) => id.generic_def(db),
603            InferBodyId::AnonConstId(id) => id.loc(db).owner.generic_def(db),
604        }
605    }
606
607    #[inline]
608    pub fn as_function(self) -> Option<FunctionId> {
609        match self {
610            InferBodyId::DefWithBodyId(DefWithBodyId::FunctionId(it)) => Some(it),
611            _ => None,
612        }
613    }
614
615    #[inline]
616    pub fn as_variant(self) -> Option<EnumVariantId> {
617        match self {
618            InferBodyId::DefWithBodyId(DefWithBodyId::VariantId(it)) => Some(it),
619            _ => None,
620        }
621    }
622
623    pub fn store_and_root_expr(self, db: &dyn HirDatabase) -> (&ExpressionStore, ExprId) {
624        match self {
625            InferBodyId::DefWithBodyId(id) => {
626                let body = Body::of(db, id);
627                (body, body.root_expr())
628            }
629            InferBodyId::AnonConstId(id) => {
630                let loc = id.loc(db);
631                let store = ExpressionStore::of(db, loc.owner);
632                (store, loc.expr)
633            }
634        }
635    }
636}
637
638pub fn setup_tracing() -> Option<tracing::subscriber::DefaultGuard> {
639    use std::env;
640    use tracing_subscriber::{Registry, layer::SubscriberExt};
641    use tracing_tree::HierarchicalLayer;
642
643    let filter: tracing_subscriber::filter::Targets =
644        env::var("SOLVER_DEBUG").ok().and_then(|it| it.parse().ok()).unwrap_or_default();
645    let layer = HierarchicalLayer::default()
646        .with_indent_lines(true)
647        .with_ansi(false)
648        .with_indent_amount(2)
649        .with_writer(std::io::stderr);
650    let subscriber = Registry::default().with(filter).with(layer);
651    Some(tracing::subscriber::set_default(subscriber))
652}
hir_ty/lib.rs

hir_ty/
lib.rs
