flux_desugar/resolver/
refinement_resolver.rs

1use std::ops::ControlFlow;
2
3use flux_common::index::IndexGen;
4use flux_errors::Errors;
5use flux_middle::{
6    ResolverOutput,
7    fhir::{self, PartialRes, Res},
8};
9use flux_syntax::{
10    surface::{self, FluxItem, Ident, NodeId, visit::Visitor as _},
11    symbols::sym,
12    walk_list,
13};
14use rustc_data_structures::{
15    fx::{FxIndexMap, FxIndexSet, IndexEntry},
16    unord::UnordMap,
17};
18use rustc_hash::FxHashMap;
19use rustc_hir::def::{
20    DefKind,
21    Namespace::{TypeNS, ValueNS},
22};
23use rustc_middle::ty::TyCtxt;
24use rustc_span::{ErrorGuaranteed, Symbol};
25
26use super::{CrateResolver, Segment};
27
28type Result<T = ()> = std::result::Result<T, ErrorGuaranteed>;
29
30#[derive(Clone, Copy, PartialEq, Eq, Debug)]
31pub(crate) enum ScopeKind {
32    FnInput,
33    FnOutput,
34    Variant,
35    Misc,
36    FnTraitInput,
37}
38
39impl ScopeKind {
40    fn is_barrier(self) -> bool {
41        matches!(self, ScopeKind::FnInput | ScopeKind::Variant)
42    }
43}
44
45/// Parameters used during gathering.
46#[derive(Debug, Clone, Copy)]
47struct ParamRes(fhir::ParamKind, NodeId);
48
49impl ParamRes {
50    fn kind(self) -> fhir::ParamKind {
51        self.0
52    }
53
54    fn param_id(self) -> NodeId {
55        self.1
56    }
57}
58
59pub(crate) trait ScopedVisitor: Sized {
60    fn is_box(&self, segment: &surface::PathSegment) -> bool;
61    fn enter_scope(&mut self, kind: ScopeKind) -> ControlFlow<()>;
62    fn exit_scope(&mut self) {}
63
64    fn wrap(self) -> ScopedVisitorWrapper<Self> {
65        ScopedVisitorWrapper(self)
66    }
67
68    fn on_implicit_param(&mut self, _ident: Ident, _kind: fhir::ParamKind, _node_id: NodeId) {}
69    fn on_generic_param(&mut self, _param: &surface::GenericParam) {}
70    fn on_refine_param(&mut self, _param: &surface::RefineParam) {}
71    fn on_enum_variant(&mut self, _variant: &surface::VariantDef) {}
72    fn on_fn_trait_input(&mut self, _in_arg: &surface::GenericArg, _node_id: NodeId) {}
73    fn on_fn_sig(&mut self, _fn_sig: &surface::FnSig) {}
74    fn on_fn_output(&mut self, _output: &surface::FnOutput) {}
75    fn on_loc(&mut self, _loc: Ident, _node_id: NodeId) {}
76    fn on_path(&mut self, _path: &surface::ExprPath) {}
77    fn on_base_sort(&mut self, _sort: &surface::BaseSort) {}
78}
79
80pub(crate) struct ScopedVisitorWrapper<V>(V);
81
82impl<V: ScopedVisitor> ScopedVisitorWrapper<V> {
83    fn with_scope(&mut self, kind: ScopeKind, f: impl FnOnce(&mut Self)) {
84        let scope = self.0.enter_scope(kind);
85        if let ControlFlow::Continue(_) = scope {
86            f(self);
87            self.0.exit_scope();
88        }
89    }
90}
91
92impl<V> std::ops::Deref for ScopedVisitorWrapper<V> {
93    type Target = V;
94
95    fn deref(&self) -> &Self::Target {
96        &self.0
97    }
98}
99impl<V> std::ops::DerefMut for ScopedVisitorWrapper<V> {
100    fn deref_mut(&mut self) -> &mut Self::Target {
101        &mut self.0
102    }
103}
104
105impl<V: ScopedVisitor> surface::visit::Visitor for ScopedVisitorWrapper<V> {
106    fn visit_trait_assoc_reft(&mut self, assoc_reft: &surface::TraitAssocReft) {
107        self.with_scope(ScopeKind::Misc, |this| {
108            surface::visit::walk_trait_assoc_reft(this, assoc_reft);
109        });
110    }
111
112    fn visit_impl_assoc_reft(&mut self, assoc_reft: &surface::ImplAssocReft) {
113        self.with_scope(ScopeKind::Misc, |this| {
114            surface::visit::walk_impl_assoc_reft(this, assoc_reft);
115        });
116    }
117
118    fn visit_qualifier(&mut self, qualifier: &surface::Qualifier) {
119        self.with_scope(ScopeKind::Misc, |this| {
120            surface::visit::walk_qualifier(this, qualifier);
121        });
122    }
123
124    fn visit_defn(&mut self, defn: &surface::SpecFunc) {
125        self.with_scope(ScopeKind::Misc, |this| {
126            surface::visit::walk_defn(this, defn);
127        });
128    }
129
130    fn visit_primop_prop(&mut self, prop: &surface::PrimOpProp) {
131        self.with_scope(ScopeKind::Misc, |this| {
132            surface::visit::walk_primop_prop(this, prop);
133        });
134    }
135
136    fn visit_generic_param(&mut self, param: &surface::GenericParam) {
137        self.on_generic_param(param);
138        surface::visit::walk_generic_param(self, param);
139    }
140
141    fn visit_refine_param(&mut self, param: &surface::RefineParam) {
142        self.on_refine_param(param);
143        surface::visit::walk_refine_param(self, param);
144    }
145
146    fn visit_ty_alias(&mut self, ty_alias: &surface::TyAlias) {
147        self.with_scope(ScopeKind::Misc, |this| {
148            surface::visit::walk_ty_alias(this, ty_alias);
149        });
150    }
151
152    fn visit_struct_def(&mut self, struct_def: &surface::StructDef) {
153        self.with_scope(ScopeKind::Misc, |this| {
154            surface::visit::walk_struct_def(this, struct_def);
155        });
156    }
157
158    fn visit_enum_def(&mut self, enum_def: &surface::EnumDef) {
159        self.with_scope(ScopeKind::Misc, |this| {
160            surface::visit::walk_enum_def(this, enum_def);
161        });
162    }
163
164    fn visit_variant(&mut self, variant: &surface::VariantDef) {
165        self.with_scope(ScopeKind::Variant, |this| {
166            this.on_enum_variant(variant);
167            surface::visit::walk_variant(this, variant);
168        });
169    }
170
171    fn visit_trait_ref(&mut self, trait_ref: &surface::TraitRef) {
172        match trait_ref.as_fn_trait_ref() {
173            Some((in_arg, out_arg)) => {
174                self.with_scope(ScopeKind::FnTraitInput, |this| {
175                    this.on_fn_trait_input(in_arg, trait_ref.node_id);
176                    surface::visit::walk_generic_arg(this, in_arg);
177                    this.with_scope(ScopeKind::Misc, |this| {
178                        surface::visit::walk_generic_arg(this, out_arg);
179                    });
180                });
181            }
182            None => {
183                self.with_scope(ScopeKind::Misc, |this| {
184                    surface::visit::walk_trait_ref(this, trait_ref);
185                });
186            }
187        }
188    }
189
190    fn visit_variant_ret(&mut self, ret: &surface::VariantRet) {
191        self.with_scope(ScopeKind::Misc, |this| {
192            surface::visit::walk_variant_ret(this, ret);
193        });
194    }
195
196    fn visit_generics(&mut self, generics: &surface::Generics) {
197        self.with_scope(ScopeKind::Misc, |this| {
198            surface::visit::walk_generics(this, generics);
199        });
200    }
201
202    fn visit_fn_sig(&mut self, fn_sig: &surface::FnSig) {
203        self.with_scope(ScopeKind::FnInput, |this| {
204            this.on_fn_sig(fn_sig);
205            surface::visit::walk_fn_sig(this, fn_sig);
206        });
207    }
208
209    fn visit_fn_output(&mut self, output: &surface::FnOutput) {
210        self.with_scope(ScopeKind::FnOutput, |this| {
211            this.on_fn_output(output);
212            surface::visit::walk_fn_output(this, output);
213        });
214    }
215
216    fn visit_fn_input(&mut self, arg: &surface::FnInput) {
217        match arg {
218            surface::FnInput::Constr(bind, _, _, node_id) => {
219                self.on_implicit_param(*bind, fhir::ParamKind::Colon, *node_id);
220            }
221            surface::FnInput::StrgRef(loc, _, node_id) => {
222                self.on_implicit_param(*loc, fhir::ParamKind::Loc, *node_id);
223            }
224            surface::FnInput::Ty(bind, ty, node_id) => {
225                if let &Some(bind) = bind {
226                    let param_kind = if let surface::TyKind::Base(_) = &ty.kind {
227                        fhir::ParamKind::Colon
228                    } else {
229                        fhir::ParamKind::Error
230                    };
231                    self.on_implicit_param(bind, param_kind, *node_id);
232                }
233            }
234        }
235        surface::visit::walk_fn_input(self, arg);
236    }
237
238    fn visit_ensures(&mut self, constraint: &surface::Ensures) {
239        if let surface::Ensures::Type(loc, _, node_id) = constraint {
240            self.on_loc(*loc, *node_id);
241        }
242        surface::visit::walk_ensures(self, constraint);
243    }
244
245    fn visit_refine_arg(&mut self, arg: &surface::RefineArg) {
246        match arg {
247            surface::RefineArg::Bind(ident, kind, _, node_id) => {
248                let kind = match kind {
249                    surface::BindKind::At => fhir::ParamKind::At,
250                    surface::BindKind::Pound => fhir::ParamKind::Pound,
251                };
252                self.on_implicit_param(*ident, kind, *node_id);
253            }
254            surface::RefineArg::Abs(..) => {
255                self.with_scope(ScopeKind::Misc, |this| {
256                    surface::visit::walk_refine_arg(this, arg);
257                });
258            }
259            surface::RefineArg::Expr(expr) => self.visit_expr(expr),
260        }
261    }
262
263    fn visit_path(&mut self, path: &surface::Path) {
264        for arg in &path.refine {
265            self.with_scope(ScopeKind::Misc, |this| this.visit_refine_arg(arg));
266        }
267        walk_list!(self, visit_path_segment, &path.segments);
268    }
269
270    fn visit_path_segment(&mut self, segment: &surface::PathSegment) {
271        let is_box = self.is_box(segment);
272        for (i, arg) in segment.args.iter().enumerate() {
273            if is_box && i == 0 {
274                self.visit_generic_arg(arg);
275            } else {
276                self.with_scope(ScopeKind::Misc, |this| this.visit_generic_arg(arg));
277            }
278        }
279    }
280
281    fn visit_ty(&mut self, ty: &surface::Ty) {
282        let node_id = ty.node_id;
283        match &ty.kind {
284            surface::TyKind::Exists { bind, .. } => {
285                self.with_scope(ScopeKind::Misc, |this| {
286                    let param = surface::RefineParam {
287                        ident: *bind,
288                        mode: None,
289                        sort: surface::Sort::Infer,
290                        node_id,
291                        span: bind.span,
292                    };
293                    this.on_refine_param(&param);
294                    surface::visit::walk_ty(this, ty);
295                });
296            }
297            surface::TyKind::GeneralExists { .. } => {
298                self.with_scope(ScopeKind::Misc, |this| {
299                    surface::visit::walk_ty(this, ty);
300                });
301            }
302            surface::TyKind::Array(..) => {
303                self.with_scope(ScopeKind::Misc, |this| {
304                    surface::visit::walk_ty(this, ty);
305                });
306            }
307            _ => surface::visit::walk_ty(self, ty),
308        }
309    }
310
311    fn visit_bty(&mut self, bty: &surface::BaseTy) {
312        match &bty.kind {
313            surface::BaseTyKind::Slice(_) => {
314                self.with_scope(ScopeKind::Misc, |this| {
315                    surface::visit::walk_bty(this, bty);
316                });
317            }
318            surface::BaseTyKind::Path(..) => {
319                surface::visit::walk_bty(self, bty);
320            }
321        }
322    }
323
324    fn visit_path_expr(&mut self, path: &surface::ExprPath) {
325        self.on_path(path);
326    }
327
328    fn visit_base_sort(&mut self, bsort: &surface::BaseSort) {
329        self.on_base_sort(bsort);
330        surface::visit::walk_base_sort(self, bsort);
331    }
332}
333
334struct ImplicitParamCollector<'a, 'tcx> {
335    tcx: TyCtxt<'tcx>,
336    path_res_map: &'a UnordMap<surface::NodeId, fhir::PartialRes>,
337    kind: ScopeKind,
338    params: Vec<(Ident, fhir::ParamKind, NodeId)>,
339}
340
341impl<'a, 'tcx> ImplicitParamCollector<'a, 'tcx> {
342    fn new(
343        tcx: TyCtxt<'tcx>,
344        path_res_map: &'a UnordMap<surface::NodeId, fhir::PartialRes>,
345        kind: ScopeKind,
346    ) -> Self {
347        Self { tcx, path_res_map, kind, params: vec![] }
348    }
349
350    fn run(
351        self,
352        f: impl FnOnce(&mut ScopedVisitorWrapper<Self>),
353    ) -> Vec<(Ident, fhir::ParamKind, NodeId)> {
354        let mut wrapped = self.wrap();
355        f(&mut wrapped);
356        wrapped.0.params
357    }
358}
359
360impl ScopedVisitor for ImplicitParamCollector<'_, '_> {
361    fn is_box(&self, segment: &surface::PathSegment) -> bool {
362        self.path_res_map
363            .get(&segment.node_id)
364            .map(|r| r.is_box(self.tcx))
365            .unwrap_or(false)
366    }
367
368    fn enter_scope(&mut self, kind: ScopeKind) -> ControlFlow<()> {
369        if self.kind == kind { ControlFlow::Continue(()) } else { ControlFlow::Break(()) }
370    }
371
372    fn on_implicit_param(&mut self, ident: Ident, param: fhir::ParamKind, node_id: NodeId) {
373        self.params.push((ident, param, node_id));
374    }
375}
376
377struct Scope {
378    kind: ScopeKind,
379    bindings: FxIndexMap<Ident, ParamRes>,
380}
381
382impl Scope {
383    fn new(kind: ScopeKind) -> Self {
384        Self { kind, bindings: Default::default() }
385    }
386}
387
388#[derive(Clone, Copy)]
389struct ParamDef {
390    ident: Ident,
391    kind: fhir::ParamKind,
392    scope: Option<NodeId>,
393}
394
395pub(crate) struct RefinementResolver<'a, 'genv, 'tcx> {
396    scopes: Vec<Scope>,
397    sort_params: FxIndexSet<Symbol>,
398    param_defs: FxIndexMap<NodeId, ParamDef>,
399    resolver: &'a mut CrateResolver<'genv, 'tcx>,
400    path_res_map: FxHashMap<NodeId, PartialRes<NodeId>>,
401    errors: Errors<'genv>,
402}
403
404impl<'a, 'genv, 'tcx> RefinementResolver<'a, 'genv, 'tcx> {
405    fn for_flux_item(resolver: &'a mut CrateResolver<'genv, 'tcx>, item: &FluxItem) -> Self {
406        let sort_params = match item {
407            FluxItem::FuncDef(defn) => &defn.sort_vars[..],
408            FluxItem::SortDecl(sort_decl) => &sort_decl.sort_vars[..],
409            FluxItem::Qualifier(_) | FluxItem::PrimOpProp(_) => &[],
410        };
411        Self::new(resolver, sort_params.iter().map(|ident| ident.name).collect())
412    }
413
414    fn for_rust_item(resolver: &'a mut CrateResolver<'genv, 'tcx>) -> Self {
415        Self::new(resolver, Default::default())
416    }
417
418    pub(crate) fn resolve_flux_item(
419        resolver: &'a mut CrateResolver<'genv, 'tcx>,
420        item: &FluxItem,
421    ) -> Result {
422        Self::for_flux_item(resolver, item).run(|r| r.visit_flux_item(item))
423    }
424
425    pub(crate) fn resolve_item(
426        resolver: &'a mut CrateResolver<'genv, 'tcx>,
427        item: &surface::Item,
428    ) -> Result {
429        IllegalBinderVisitor::new(resolver).run(|vis| vis.visit_item(item))?;
430        Self::for_rust_item(resolver).run(|vis| vis.visit_item(item))
431    }
432
433    pub(crate) fn resolve_trait_item(
434        resolver: &'a mut CrateResolver<'genv, 'tcx>,
435        item: &surface::TraitItemFn,
436    ) -> Result {
437        IllegalBinderVisitor::new(resolver).run(|vis| vis.visit_trait_item(item))?;
438        Self::for_rust_item(resolver).run(|vis| vis.visit_trait_item(item))
439    }
440
441    pub(crate) fn resolve_impl_item(
442        resolver: &'a mut CrateResolver<'genv, 'tcx>,
443        item: &surface::ImplItemFn,
444    ) -> Result {
445        IllegalBinderVisitor::new(resolver).run(|vis| vis.visit_impl_item(item))?;
446        Self::for_rust_item(resolver).run(|vis| vis.visit_impl_item(item))
447    }
448
449    fn new(resolver: &'a mut CrateResolver<'genv, 'tcx>, sort_params: FxIndexSet<Symbol>) -> Self {
450        let errors = Errors::new(resolver.genv.sess());
451        Self {
452            resolver,
453            sort_params,
454            param_defs: Default::default(),
455            scopes: Default::default(),
456            path_res_map: Default::default(),
457            errors,
458        }
459    }
460
461    fn run(self, f: impl FnOnce(&mut ScopedVisitorWrapper<Self>)) -> Result {
462        let mut wrapper = self.wrap();
463        f(&mut wrapper);
464        wrapper.0.finish()
465    }
466
467    fn define_param(
468        &mut self,
469        ident: Ident,
470        kind: fhir::ParamKind,
471        param_id: NodeId,
472        scope: Option<NodeId>,
473    ) {
474        self.param_defs
475            .insert(param_id, ParamDef { ident, kind, scope });
476
477        let scope = self.scopes.last_mut().unwrap();
478        match scope.bindings.entry(ident) {
479            IndexEntry::Occupied(entry) => {
480                let param_def = self.param_defs[&entry.get().param_id()];
481                self.errors
482                    .emit(errors::DuplicateParam::new(param_def.ident, ident));
483            }
484            IndexEntry::Vacant(entry) => {
485                entry.insert(ParamRes(kind, param_id));
486            }
487        }
488    }
489
490    fn find(&mut self, ident: Ident) -> Option<ParamRes> {
491        for scope in self.scopes.iter().rev() {
492            if let Some(res) = scope.bindings.get(&ident) {
493                return Some(*res);
494            }
495
496            if scope.kind.is_barrier() {
497                return None;
498            }
499        }
500        None
501    }
502
503    fn resolve_path(&mut self, path: &surface::ExprPath) {
504        if let [segment] = &path.segments[..]
505            && let Some(res) = self.try_resolve_param(segment.ident)
506        {
507            self.path_res_map.insert(path.node_id, PartialRes::new(res));
508            return;
509        }
510        if let Some(res) = self.try_resolve_expr_with_ribs(&path.segments) {
511            self.path_res_map.insert(path.node_id, res);
512            return;
513        }
514        if let [segment] = &path.segments[..]
515            && let Some(res) = self.try_resolve_global_func(segment.ident)
516        {
517            self.path_res_map.insert(path.node_id, PartialRes::new(res));
518            return;
519        }
520
521        self.errors.emit(errors::UnresolvedVar::from_path(path));
522    }
523
524    fn resolve_ident(&mut self, ident: Ident, node_id: NodeId) {
525        if let Some(res) = self.try_resolve_param(ident) {
526            self.path_res_map.insert(node_id, PartialRes::new(res));
527            return;
528        }
529        if let Some(res) = self.try_resolve_expr_with_ribs(&[ident]) {
530            self.path_res_map.insert(node_id, res);
531            return;
532        }
533        if let Some(res) = self.try_resolve_global_func(ident) {
534            self.path_res_map.insert(node_id, PartialRes::new(res));
535            return;
536        }
537        self.errors.emit(errors::UnresolvedVar::from_ident(ident));
538    }
539
540    fn try_resolve_expr_with_ribs<S: Segment>(
541        &mut self,
542        segments: &[S],
543    ) -> Option<PartialRes<NodeId>> {
544        if let Some(partial_res) = self.resolver.resolve_path_with_ribs(segments, ValueNS) {
545            return Some(partial_res.map_param_id(|p| p));
546        }
547
548        self.resolver
549            .resolve_path_with_ribs(segments, TypeNS)
550            .map(|r| r.map_param_id(|p| p))
551    }
552
553    fn try_resolve_param(&mut self, ident: Ident) -> Option<Res<NodeId>> {
554        let res = self.find(ident)?;
555
556        if let fhir::ParamKind::Error = res.kind() {
557            self.errors.emit(errors::InvalidUnrefinedParam::new(ident));
558        }
559        Some(Res::Param(res.kind(), res.param_id()))
560    }
561
562    fn try_resolve_global_func(&mut self, ident: Ident) -> Option<Res<NodeId>> {
563        let kind = self.resolver.func_decls.get(&ident.name)?;
564        Some(Res::GlobalFunc(*kind))
565    }
566
567    fn resolve_sort_path(&mut self, path: &surface::SortPath) {
568        let res = self
569            .try_resolve_sort_param(path)
570            .or_else(|| self.try_resolve_sort_with_ribs(path))
571            .or_else(|| self.try_resolve_user_sort(path))
572            .or_else(|| self.try_resolve_prim_sort(path));
573
574        if let Some(res) = res {
575            self.resolver
576                .output
577                .sort_path_res_map
578                .insert(path.node_id, res);
579        } else {
580            self.errors.emit(errors::UnresolvedSort::new(path));
581        }
582    }
583
584    fn try_resolve_sort_param(&self, path: &surface::SortPath) -> Option<fhir::SortRes> {
585        let [segment] = &path.segments[..] else { return None };
586        self.sort_params
587            .get_index_of(&segment.name)
588            .map(fhir::SortRes::SortParam)
589    }
590
591    fn try_resolve_sort_with_ribs(&mut self, path: &surface::SortPath) -> Option<fhir::SortRes> {
592        let partial_res = self
593            .resolver
594            .resolve_path_with_ribs(&path.segments, TypeNS)?;
595        match (partial_res.base_res(), partial_res.unresolved_segments()) {
596            (fhir::Res::Def(DefKind::Struct | DefKind::Enum, def_id), 0) => {
597                Some(fhir::SortRes::Adt(def_id))
598            }
599            (fhir::Res::Def(DefKind::TyParam, def_id), 0) => Some(fhir::SortRes::TyParam(def_id)),
600            (fhir::Res::SelfTyParam { trait_ }, 0) => {
601                Some(fhir::SortRes::SelfParam { trait_id: trait_ })
602            }
603            (fhir::Res::SelfTyParam { trait_ }, 1) => {
604                let ident = *path.segments.last().unwrap();
605                Some(fhir::SortRes::SelfParamAssoc { trait_id: trait_, ident })
606            }
607            (fhir::Res::SelfTyAlias { alias_to, .. }, 0) => {
608                Some(fhir::SortRes::SelfAlias { alias_to })
609            }
610            _ => None,
611        }
612    }
613
614    fn try_resolve_user_sort(&self, path: &surface::SortPath) -> Option<fhir::SortRes> {
615        let [segment] = &path.segments[..] else { return None };
616        self.resolver
617            .sort_decls
618            .get(&segment.name)
619            .map(|decl| fhir::SortRes::User(*decl))
620    }
621
622    fn try_resolve_prim_sort(&self, path: &surface::SortPath) -> Option<fhir::SortRes> {
623        let [segment] = &path.segments[..] else { return None };
624        if segment.name == sym::int {
625            Some(fhir::SortRes::PrimSort(fhir::PrimSort::Int))
626        } else if segment.name == sym::bool {
627            Some(fhir::SortRes::PrimSort(fhir::PrimSort::Bool))
628        } else if segment.name == sym::char {
629            Some(fhir::SortRes::PrimSort(fhir::PrimSort::Char))
630        } else if segment.name == sym::real {
631            Some(fhir::SortRes::PrimSort(fhir::PrimSort::Real))
632        } else if segment.name == sym::Set {
633            Some(fhir::SortRes::PrimSort(fhir::PrimSort::Set))
634        } else if segment.name == sym::Map {
635            Some(fhir::SortRes::PrimSort(fhir::PrimSort::Map))
636        } else if segment.name == sym::str {
637            Some(fhir::SortRes::PrimSort(fhir::PrimSort::Str))
638        } else {
639            None
640        }
641    }
642
643    pub(crate) fn finish(self) -> Result {
644        let param_id_gen = IndexGen::new();
645        let mut params = FxIndexMap::default();
646
647        // Create an `fhir::ParamId` for all parameters used in a path before iterating over
648        // `param_defs` such that we can skip `fhir::ParamKind::Colon` if the param wasn't used
649        for (node_id, res) in self.path_res_map {
650            let res = res.map_param_id(|param_id| {
651                *params
652                    .entry(param_id)
653                    .or_insert_with(|| param_id_gen.fresh())
654            });
655            self.resolver.output.expr_path_res_map.insert(node_id, res);
656        }
657
658        // At this point, the `params` map contains all parameters that were used in an expression,
659        // so we can safely skip `ParamKind::Colon` if there's no entry for it.
660        for (param_id, param_def) in self.param_defs {
661            let name = match param_def.kind {
662                fhir::ParamKind::Colon => {
663                    let Some(name) = params.get(&param_id) else { continue };
664                    *name
665                }
666                fhir::ParamKind::Error => continue,
667                _ => {
668                    params
669                        .get(&param_id)
670                        .copied()
671                        .unwrap_or_else(|| param_id_gen.fresh())
672                }
673            };
674            let output = &mut self.resolver.output;
675            output
676                .param_res_map
677                .insert(param_id, (name, param_def.kind));
678
679            if let Some(scope) = param_def.scope {
680                output
681                    .implicit_params
682                    .entry(scope)
683                    .or_default()
684                    .push((param_def.ident, param_id));
685            }
686        }
687        self.errors.into_result()
688    }
689
690    fn resolver_output(&self) -> &ResolverOutput {
691        &self.resolver.output
692    }
693}
694
695impl ScopedVisitor for RefinementResolver<'_, '_, '_> {
696    fn is_box(&self, segment: &surface::PathSegment) -> bool {
697        self.resolver_output()
698            .path_res_map
699            .get(&segment.node_id)
700            .map(|r| r.is_box(self.resolver.genv.tcx()))
701            .unwrap_or(false)
702    }
703
704    fn enter_scope(&mut self, kind: ScopeKind) -> ControlFlow<()> {
705        self.scopes.push(Scope::new(kind));
706        ControlFlow::Continue(())
707    }
708
709    fn exit_scope(&mut self) {
710        self.scopes.pop();
711    }
712
713    fn on_fn_trait_input(&mut self, in_arg: &surface::GenericArg, trait_node_id: NodeId) {
714        let params = ImplicitParamCollector::new(
715            self.resolver.genv.tcx(),
716            &self.resolver.output.path_res_map,
717            ScopeKind::FnTraitInput,
718        )
719        .run(|vis| vis.visit_generic_arg(in_arg));
720        for (ident, kind, node_id) in params {
721            self.define_param(ident, kind, node_id, Some(trait_node_id));
722        }
723    }
724
725    fn on_enum_variant(&mut self, variant: &surface::VariantDef) {
726        let params = ImplicitParamCollector::new(
727            self.resolver.genv.tcx(),
728            &self.resolver.output.path_res_map,
729            ScopeKind::Variant,
730        )
731        .run(|vis| vis.visit_variant(variant));
732        for (ident, kind, node_id) in params {
733            self.define_param(ident, kind, node_id, Some(variant.node_id));
734        }
735    }
736
737    fn on_fn_sig(&mut self, fn_sig: &surface::FnSig) {
738        let params = ImplicitParamCollector::new(
739            self.resolver.genv.tcx(),
740            &self.resolver.output.path_res_map,
741            ScopeKind::FnInput,
742        )
743        .run(|vis| vis.visit_fn_sig(fn_sig));
744        for (ident, kind, param_id) in params {
745            self.define_param(ident, kind, param_id, Some(fn_sig.node_id));
746        }
747    }
748
749    fn on_fn_output(&mut self, output: &surface::FnOutput) {
750        let params = ImplicitParamCollector::new(
751            self.resolver.genv.tcx(),
752            &self.resolver.output.path_res_map,
753            ScopeKind::FnOutput,
754        )
755        .run(|vis| vis.visit_fn_output(output));
756        for (ident, kind, param_id) in params {
757            self.define_param(ident, kind, param_id, Some(output.node_id));
758        }
759    }
760
761    fn on_refine_param(&mut self, param: &surface::RefineParam) {
762        self.define_param(param.ident, fhir::ParamKind::Explicit(param.mode), param.node_id, None);
763    }
764
765    fn on_loc(&mut self, loc: Ident, node_id: NodeId) {
766        self.resolve_ident(loc, node_id);
767    }
768
769    fn on_path(&mut self, path: &surface::ExprPath) {
770        self.resolve_path(path);
771    }
772
773    fn on_base_sort(&mut self, sort: &surface::BaseSort) {
774        match sort {
775            surface::BaseSort::Path(path) => {
776                self.resolve_sort_path(path);
777            }
778            surface::BaseSort::BitVec(_) => {}
779            surface::BaseSort::SortOf(..) => {}
780        }
781    }
782}
783
784struct IllegalBinderVisitor<'a, 'genv, 'tcx> {
785    scopes: Vec<ScopeKind>,
786    resolver: &'a CrateResolver<'genv, 'tcx>,
787    errors: Errors<'genv>,
788}
789
790impl<'a, 'genv, 'tcx> IllegalBinderVisitor<'a, 'genv, 'tcx> {
791    fn new(resolver: &'a mut CrateResolver<'genv, 'tcx>) -> Self {
792        let errors = Errors::new(resolver.genv.sess());
793        Self { scopes: vec![], resolver, errors }
794    }
795
796    fn run(self, f: impl FnOnce(&mut ScopedVisitorWrapper<Self>)) -> Result {
797        let mut vis = self.wrap();
798        f(&mut vis);
799        vis.0.errors.into_result()
800    }
801}
802
803impl ScopedVisitor for IllegalBinderVisitor<'_, '_, '_> {
804    fn is_box(&self, segment: &surface::PathSegment) -> bool {
805        self.resolver
806            .output
807            .path_res_map
808            .get(&segment.node_id)
809            .map(|r| r.is_box(self.resolver.genv.tcx()))
810            .unwrap_or(false)
811    }
812
813    fn enter_scope(&mut self, kind: ScopeKind) -> ControlFlow<()> {
814        self.scopes.push(kind);
815        ControlFlow::Continue(())
816    }
817
818    fn exit_scope(&mut self) {
819        self.scopes.pop();
820    }
821
822    fn on_implicit_param(&mut self, ident: Ident, param_kind: fhir::ParamKind, _: NodeId) {
823        let Some(scope_kind) = self.scopes.last() else { return };
824        let (allowed, bind_kind) = match param_kind {
825            fhir::ParamKind::At => {
826                (
827                    matches!(
828                        scope_kind,
829                        ScopeKind::FnInput | ScopeKind::FnTraitInput | ScopeKind::Variant
830                    ),
831                    surface::BindKind::At,
832                )
833            }
834            fhir::ParamKind::Pound => {
835                (matches!(scope_kind, ScopeKind::FnOutput), surface::BindKind::Pound)
836            }
837            fhir::ParamKind::Colon
838            | fhir::ParamKind::Loc
839            | fhir::ParamKind::Error
840            | fhir::ParamKind::Explicit(..) => return,
841        };
842        if !allowed {
843            self.errors
844                .emit(errors::IllegalBinder::new(ident.span, bind_kind));
845        }
846    }
847}
848
849mod errors {
850    use flux_errors::E0999;
851    use flux_macros::Diagnostic;
852    use flux_syntax::surface;
853    use itertools::Itertools;
854    use rustc_span::{Span, Symbol, symbol::Ident};
855
856    #[derive(Diagnostic)]
857    #[diag(desugar_duplicate_param, code = E0999)]
858    pub(super) struct DuplicateParam {
859        #[primary_span]
860        #[label]
861        span: Span,
862        name: Symbol,
863        #[label(desugar_first_use)]
864        first_use: Span,
865    }
866
867    impl DuplicateParam {
868        pub(super) fn new(old_ident: Ident, new_ident: Ident) -> Self {
869            debug_assert_eq!(old_ident.name, new_ident.name);
870            Self { span: new_ident.span, name: new_ident.name, first_use: old_ident.span }
871        }
872    }
873
874    #[derive(Diagnostic)]
875    #[diag(desugar_unresolved_sort, code = E0999)]
876    pub(super) struct UnresolvedSort {
877        #[primary_span]
878        #[label]
879        span: Span,
880        name: String,
881    }
882
883    impl UnresolvedSort {
884        pub(super) fn new(path: &surface::SortPath) -> Self {
885            Self {
886                span: path
887                    .segments
888                    .iter()
889                    .map(|ident| ident.span)
890                    .reduce(Span::to)
891                    .unwrap_or_default(),
892                name: format!("{}", path.segments.iter().format("::")),
893            }
894        }
895    }
896
897    #[derive(Diagnostic)]
898    #[diag(desugar_unresolved_var, code = E0999)]
899    pub(super) struct UnresolvedVar {
900        #[primary_span]
901        #[label]
902        span: Span,
903        var: String,
904    }
905
906    impl UnresolvedVar {
907        pub(super) fn from_path(path: &surface::ExprPath) -> Self {
908            Self {
909                span: path.span,
910                var: format!(
911                    "{}",
912                    path.segments
913                        .iter()
914                        .format_with("::", |s, f| f(&s.ident.name))
915                ),
916            }
917        }
918
919        pub(super) fn from_ident(ident: Ident) -> Self {
920            Self { span: ident.span, var: format!("{ident}") }
921        }
922    }
923
924    #[derive(Diagnostic)]
925    #[diag(desugar_invalid_unrefined_param, code = E0999)]
926    pub(super) struct InvalidUnrefinedParam {
927        #[primary_span]
928        #[label]
929        span: Span,
930        var: Ident,
931    }
932
933    impl InvalidUnrefinedParam {
934        pub(super) fn new(var: Ident) -> Self {
935            Self { var, span: var.span }
936        }
937    }
938
939    #[derive(Diagnostic)]
940    #[diag(desugar_illegal_binder, code = E0999)]
941    pub(super) struct IllegalBinder {
942        #[primary_span]
943        #[label]
944        span: Span,
945        kind: &'static str,
946    }
947
948    impl IllegalBinder {
949        pub(super) fn new(span: Span, kind: surface::BindKind) -> Self {
950            Self { span, kind: kind.token_str() }
951        }
952    }
953}