diff options
Diffstat (limited to 'compiler/rustc_hir_analysis')
6 files changed, 200 insertions, 37 deletions
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs index 63a0e7d31c3..1a925597c6c 100644 --- a/compiler/rustc_hir_analysis/src/collect.rs +++ b/compiler/rustc_hir_analysis/src/collect.rs @@ -46,7 +46,7 @@ use tracing::{debug, instrument}; use crate::check::intrinsic::intrinsic_operation_unsafety; use crate::errors; -use crate::hir_ty_lowering::{HirTyLowerer, RegionInferReason}; +use crate::hir_ty_lowering::{FeedConstTy, HirTyLowerer, RegionInferReason}; pub(crate) mod dump; mod generics_of; @@ -88,6 +88,7 @@ pub fn provide(providers: &mut Providers) { coroutine_for_closure, opaque_ty_origin, rendered_precise_capturing_args, + const_param_default, ..*providers }; } @@ -1790,3 +1791,23 @@ fn rendered_precise_capturing_args<'tcx>( _ => None, }) } + +fn const_param_default<'tcx>( + tcx: TyCtxt<'tcx>, + def_id: LocalDefId, +) -> ty::EarlyBinder<'tcx, Const<'tcx>> { + let default_ct = match tcx.hir_node_by_def_id(def_id) { + hir::Node::GenericParam(hir::GenericParam { + kind: hir::GenericParamKind::Const { default: Some(ct), .. }, + .. + }) => ct, + _ => span_bug!( + tcx.def_span(def_id), + "`const_param_default` expected a generic parameter with a constant" + ), + }; + let icx = ItemCtxt::new(tcx, def_id); + // FIXME(const_generics): investigate which places do and don't need const ty feeding + let ct = icx.lowerer().lower_const_arg(default_ct, FeedConstTy::No); + ty::EarlyBinder::bind(ct) +} diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs index 7ce12d48160..0f37d61beb0 100644 --- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs +++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs @@ -223,11 +223,12 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen trace!(?predicates); } hir::GenericParamKind::Const { .. } => { + let param_def_id = param.def_id.to_def_id(); let ct_ty = tcx - .type_of(param.def_id.to_def_id()) + .type_of(param_def_id) .no_bound_vars() .expect("const parameters cannot be generic"); - let ct = icx.lowerer().lower_const_param(param.hir_id); + let ct = icx.lowerer().lower_const_param(param_def_id, param.hir_id); predicates .insert((ty::ClauseKind::ConstArgHasType(ct, ct_ty).upcast(tcx), param.span)); } diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs index 1cade402c54..6ebe1cedcaf 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs @@ -19,7 +19,9 @@ use tracing::{debug, instrument}; use super::errors::GenericsArgsErrExtend; use crate::bounds::Bounds; use crate::errors; -use crate::hir_ty_lowering::{AssocItemQSelf, HirTyLowerer, PredicateFilter, RegionInferReason}; +use crate::hir_ty_lowering::{ + AssocItemQSelf, FeedConstTy, HirTyLowerer, PredicateFilter, RegionInferReason, +}; impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { /// Add a `Sized` bound to the `bounds` if appropriate. @@ -346,9 +348,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { hir::AssocItemConstraintKind::Equality { term } => { let term = match term { hir::Term::Ty(ty) => self.lower_ty(ty).into(), - hir::Term::Const(ct) => { - ty::Const::from_const_arg(tcx, ct, ty::FeedConstTy::No).into() - } + hir::Term::Const(ct) => self.lower_const_arg(ct, FeedConstTy::No).into(), }; // Find any late-bound regions declared in `ty` that are not diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs index 6e8a9ded4f3..ae1279d428c 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs @@ -115,17 +115,22 @@ fn generic_arg_mismatch_err( } } (GenericArg::Const(cnst), GenericParamDefKind::Type { .. }) => { - // FIXME(min_generic_const_args): once ConstArgKind::Path is used for non-params too, - // this should match against that instead of ::Anon - if let hir::ConstArgKind::Anon(anon) = cnst.kind + if let hir::ConstArgKind::Path(qpath) = cnst.kind + && let rustc_hir::QPath::Resolved(_, path) = qpath + && let Res::Def(DefKind::Fn { .. }, id) = path.res + { + err.help(format!("`{}` is a function item, not a type", tcx.item_name(id))); + err.help("function item types cannot be named directly"); + } else if let hir::ConstArgKind::Anon(anon) = cnst.kind && let body = tcx.hir().body(anon.body) && let rustc_hir::ExprKind::Path(rustc_hir::QPath::Resolved(_, path)) = body.value.kind + && let Res::Def(DefKind::Fn { .. }, id) = path.res { - if let Res::Def(DefKind::Fn { .. }, id) = path.res { - err.help(format!("`{}` is a function item, not a type", tcx.item_name(id))); - err.help("function item types cannot be named directly"); - } + // FIXME(min_generic_const_args): this branch is dead once new const path lowering + // (for single-segment paths) is no longer gated + err.help(format!("`{}` is a function item, not a type", tcx.item_name(id))); + err.help("function item types cannot be named directly"); } } _ => {} diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs index ed39708981b..f7035531e88 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs @@ -30,7 +30,7 @@ use rustc_errors::{ Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, FatalError, struct_span_code_err, }; use rustc_hir as hir; -use rustc_hir::def::{CtorOf, DefKind, Namespace, Res}; +use rustc_hir::def::{CtorKind, CtorOf, DefKind, Namespace, Res}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::{GenericArg, GenericArgs, HirId}; use rustc_infer::infer::{InferCtxt, TyCtxtInferExt}; @@ -217,6 +217,23 @@ impl AssocItemQSelf { } } +/// In some cases, [`hir::ConstArg`]s that are being used in the type system +/// through const generics need to have their type "fed" to them +/// using the query system. +/// +/// Use this enum with [`Const::from_const_arg`] to instruct it with the +/// desired behavior. +#[derive(Debug, Clone, Copy)] +pub enum FeedConstTy { + /// Feed the type. + /// + /// The `DefId` belongs to the const param that we are supplying + /// this (anon) const arg to. + Param(DefId), + /// Don't feed the type. + No, +} + /// New-typed boolean indicating whether explicit late-bound lifetimes /// are present in a set of generic arguments. /// @@ -500,8 +517,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { handle_ty_args(has_default, &inf.to_ty()) } (GenericParamDefKind::Const { .. }, GenericArg::Const(ct)) => { - ty::Const::from_const_arg(tcx, ct, ty::FeedConstTy::Param(param.def_id)) - .into() + self.lowerer.lower_const_arg(ct, FeedConstTy::Param(param.def_id)).into() } (&GenericParamDefKind::Const { .. }, GenericArg::Infer(inf)) => { self.lowerer.ct_infer(Some(param), inf.span).into() @@ -979,8 +995,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let term: ty::Term<'_> = match term { hir::Term::Ty(ty) => self.lower_ty(ty).into(), hir::Term::Const(ct) => { - ty::Const::from_const_arg(tcx, ct, ty::FeedConstTy::No) - .into() + self.lower_const_arg(ct, FeedConstTy::No).into() } }; // FIXME(#97583): This isn't syntactically well-formed! @@ -2025,23 +2040,138 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { /// /// Early-bound const parameters get lowered to [`ty::ConstKind::Param`] /// and late-bound ones to [`ty::ConstKind::Bound`]. - pub(crate) fn lower_const_param(&self, hir_id: HirId) -> Const<'tcx> { + pub(crate) fn lower_const_param(&self, param_def_id: DefId, path_hir_id: HirId) -> Const<'tcx> { let tcx = self.tcx(); - match tcx.named_bound_var(hir_id) { - Some(rbv::ResolvedArg::EarlyBound(def_id)) => { + + match tcx.named_bound_var(path_hir_id) { + Some(rbv::ResolvedArg::EarlyBound(_)) => { // Find the name and index of the const parameter by indexing the generics of // the parent item and construct a `ParamConst`. - let item_def_id = tcx.local_parent(def_id); + let item_def_id = tcx.parent(param_def_id); let generics = tcx.generics_of(item_def_id); - let index = generics.param_def_id_to_index[&def_id.to_def_id()]; - let name = tcx.item_name(def_id.to_def_id()); + let index = generics.param_def_id_to_index[¶m_def_id]; + let name = tcx.item_name(param_def_id); ty::Const::new_param(tcx, ty::ParamConst::new(index, name)) } Some(rbv::ResolvedArg::LateBound(debruijn, index, _)) => { ty::Const::new_bound(tcx, debruijn, ty::BoundVar::from_u32(index)) } Some(rbv::ResolvedArg::Error(guar)) => ty::Const::new_error(tcx, guar), - arg => bug!("unexpected bound var resolution for {:?}: {arg:?}", hir_id), + arg => bug!("unexpected bound var resolution for {:?}: {arg:?}", path_hir_id), + } + } + + /// Convert a [`hir::ConstArg`] to a [`ty::Const`](Const). + #[instrument(skip(self), level = "debug")] + pub fn lower_const_arg( + &self, + const_arg: &hir::ConstArg<'tcx>, + feed: FeedConstTy, + ) -> Const<'tcx> { + let tcx = self.tcx(); + + if let FeedConstTy::Param(param_def_id) = feed + && let hir::ConstArgKind::Anon(anon) = &const_arg.kind + { + tcx.feed_anon_const_type(anon.def_id, tcx.type_of(param_def_id)); + } + + let hir_id = const_arg.hir_id; + match const_arg.kind { + hir::ConstArgKind::Path(hir::QPath::Resolved(maybe_qself, path)) => { + debug!(?maybe_qself, ?path); + let opt_self_ty = maybe_qself.as_ref().map(|qself| self.lower_ty(qself)); + self.lower_const_path_resolved(opt_self_ty, path, hir_id) + } + hir::ConstArgKind::Path(qpath) => ty::Const::new_error_with_message( + tcx, + qpath.span(), + format!("Const::lower_const_arg: invalid qpath {qpath:?}"), + ), + hir::ConstArgKind::Anon(anon) => Const::from_anon_const(tcx, anon.def_id), + } + } + + fn lower_const_path_resolved( + &self, + opt_self_ty: Option<Ty<'tcx>>, + path: &hir::Path<'tcx>, + hir_id: HirId, + ) -> Const<'tcx> { + let tcx = self.tcx(); + let span = path.span; + match path.res { + Res::Def(DefKind::ConstParam, def_id) => { + assert_eq!(opt_self_ty, None); + let _ = self.prohibit_generic_args( + path.segments.iter(), + GenericsArgsErrExtend::Param(def_id), + ); + self.lower_const_param(def_id, hir_id) + } + Res::Def(DefKind::Const | DefKind::Ctor(_, CtorKind::Const), did) => { + assert_eq!(opt_self_ty, None); + let _ = self.prohibit_generic_args( + path.segments.split_last().unwrap().1.iter(), + GenericsArgsErrExtend::None, + ); + let args = self.lower_generic_args_of_path_segment( + span, + did, + path.segments.last().unwrap(), + ); + ty::Const::new_unevaluated(tcx, ty::UnevaluatedConst::new(did, args)) + } + Res::Def(DefKind::Static { .. }, _) => { + span_bug!(span, "use of bare `static` ConstArgKind::Path's not yet supported") + } + // FIXME(const_generics): create real const to allow fn items as const paths + Res::Def(DefKind::Fn | DefKind::AssocFn, _) => ty::Const::new_error_with_message( + tcx, + span, + "fn items cannot be used as const args", + ), + + // Exhaustive match to be clear about what exactly we're considering to be + // an invalid Res for a const path. + Res::Def( + DefKind::Mod + | DefKind::Enum + | DefKind::Variant + | DefKind::Ctor(CtorOf::Variant, CtorKind::Fn) + | DefKind::Struct + | DefKind::Ctor(CtorOf::Struct, CtorKind::Fn) + | DefKind::OpaqueTy + | DefKind::TyAlias + | DefKind::TraitAlias + | DefKind::AssocTy + | DefKind::Union + | DefKind::Trait + | DefKind::ForeignTy + | DefKind::AssocConst + | DefKind::TyParam + | DefKind::Macro(_) + | DefKind::LifetimeParam + | DefKind::Use + | DefKind::ForeignMod + | DefKind::AnonConst + | DefKind::InlineConst + | DefKind::Field + | DefKind::Impl { .. } + | DefKind::Closure + | DefKind::ExternCrate + | DefKind::GlobalAsm + | DefKind::SyntheticCoroutineBody, + _, + ) + | Res::PrimTy(_) + | Res::SelfTyParam { .. } + | Res::SelfTyAlias { .. } + | Res::SelfCtor(_) + | Res::Local(_) + | Res::ToolMod + | Res::NonMacroAttr(_) + | Res::Err => Const::new_error_with_message(tcx, span, "invalid Res for const path"), } } @@ -2053,14 +2183,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } } - /// Lower a type from the HIR to our internal notion of a type given some extra data for diagnostics. - /// - /// Extra diagnostic data: - /// - /// 1. `borrowed`: Whether trait object types are borrowed like in `&dyn Trait`. - /// Used to avoid emitting redundant errors. - /// 2. `in_path`: Whether the type appears inside of a path. - /// Used to provide correct diagnostics for bare trait object types. + /// Lower a type from the HIR to our internal notion of a type. #[instrument(level = "debug", skip(self), ret)] pub fn lower_ty(&self, hir_ty: &hir::Ty<'tcx>) -> Ty<'tcx> { let tcx = self.tcx(); @@ -2189,7 +2312,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let length = match length { hir::ArrayLen::Infer(inf) => self.ct_infer(None, inf.span), hir::ArrayLen::Body(constant) => { - ty::Const::from_const_arg(tcx, constant, ty::FeedConstTy::No) + self.lower_const_arg(constant, FeedConstTy::No) } }; @@ -2247,7 +2370,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { .type_of(def_id) .no_bound_vars() .expect("const parameter types cannot be generic"); - let ct = self.lower_const_param(expr.hir_id); + let ct = self.lower_const_param(def_id, expr.hir_id); (ct, ty) } diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs index 5830636c6e8..564e45c677d 100644 --- a/compiler/rustc_hir_analysis/src/lib.rs +++ b/compiler/rustc_hir_analysis/src/lib.rs @@ -97,12 +97,14 @@ use rustc_hir::def::DefKind; use rustc_middle::middle; use rustc_middle::mir::interpret::GlobalId; use rustc_middle::query::Providers; -use rustc_middle::ty::{self, Ty, TyCtxt}; +use rustc_middle::ty::{self, Const, Ty, TyCtxt}; use rustc_session::parse::feature_err; use rustc_span::Span; use rustc_span::symbol::sym; use rustc_trait_selection::traits; +use self::hir_ty_lowering::{FeedConstTy, HirTyLowerer}; + rustc_fluent_macro::fluent_messages! { "../messages.ftl" } fn require_c_abi_if_c_variadic( @@ -226,3 +228,14 @@ pub fn lower_ty<'tcx>(tcx: TyCtxt<'tcx>, hir_ty: &hir::Ty<'tcx>) -> Ty<'tcx> { let env_def_id = tcx.hir().get_parent_item(hir_ty.hir_id); collect::ItemCtxt::new(tcx, env_def_id.def_id).lower_ty(hir_ty) } + +/// This is for rustdoc. +// FIXME(const_generics): having special methods for rustdoc in `rustc_hir_analysis` is cursed +pub fn lower_const_arg_for_rustdoc<'tcx>( + tcx: TyCtxt<'tcx>, + hir_ct: &hir::ConstArg<'tcx>, + feed: FeedConstTy, +) -> Const<'tcx> { + let env_def_id = tcx.hir().get_parent_item(hir_ct.hir_id); + collect::ItemCtxt::new(tcx, env_def_id.def_id).lowerer().lower_const_arg(hir_ct, feed) +} |