diff options
Diffstat (limited to 'compiler/rustc_hir_analysis/src/variance')
-rw-r--r-- | compiler/rustc_hir_analysis/src/variance/constraints.rs | 16 | ||||
-rw-r--r-- | compiler/rustc_hir_analysis/src/variance/mod.rs | 16 | ||||
-rw-r--r-- | compiler/rustc_hir_analysis/src/variance/terms.rs | 6 | ||||
-rw-r--r-- | compiler/rustc_hir_analysis/src/variance/test.rs | 15 |
4 files changed, 33 insertions, 20 deletions
diff --git a/compiler/rustc_hir_analysis/src/variance/constraints.rs b/compiler/rustc_hir_analysis/src/variance/constraints.rs index 8a40509d7..61d9c989e 100644 --- a/compiler/rustc_hir_analysis/src/variance/constraints.rs +++ b/compiler/rustc_hir_analysis/src/variance/constraints.rs @@ -6,7 +6,7 @@ use hir::def_id::{DefId, LocalDefId}; use rustc_hir as hir; use rustc_hir::def::DefKind; -use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt}; +use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_middle::ty::{GenericArgKind, GenericArgsRef}; use super::terms::VarianceTerm::*; @@ -78,9 +78,7 @@ pub fn add_constraints_from_crate<'a, 'tcx>( } } DefKind::Fn | DefKind::AssocFn => constraint_cx.build_constraints_for_item(def_id), - DefKind::TyAlias { lazy } - if lazy || tcx.type_of(def_id).instantiate_identity().has_opaque_types() => - { + DefKind::TyAlias if tcx.type_alias_is_lazy(def_id) => { constraint_cx.build_constraints_for_item(def_id) } _ => {} @@ -110,8 +108,8 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> { // The type as returned by `type_of` is the underlying type and generally not a weak projection. // Therefore we need to check the `DefKind` first. - if let DefKind::TyAlias { lazy } = tcx.def_kind(def_id) - && (lazy || ty.has_opaque_types()) + if let DefKind::TyAlias = tcx.def_kind(def_id) + && tcx.type_alias_is_lazy(def_id) { self.add_constraints_from_ty(current_item, ty, self.covariant); return; @@ -314,11 +312,7 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> { // types, where we use Error as the Self type } - ty::Placeholder(..) - | ty::GeneratorWitness(..) - | ty::GeneratorWitnessMIR(..) - | ty::Bound(..) - | ty::Infer(..) => { + ty::Placeholder(..) | ty::GeneratorWitness(..) | ty::Bound(..) | ty::Infer(..) => { bug!("unexpected type encountered in variance inference: {}", ty); } } diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs index d91d9fcbc..85e0000ab 100644 --- a/compiler/rustc_hir_analysis/src/variance/mod.rs +++ b/compiler/rustc_hir_analysis/src/variance/mod.rs @@ -8,7 +8,7 @@ use rustc_hir::def::DefKind; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_middle::query::Providers; use rustc_middle::ty::{self, CrateVariancesMap, GenericArgsRef, Ty, TyCtxt}; -use rustc_middle::ty::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt}; +use rustc_middle::ty::{TypeSuperVisitable, TypeVisitable}; use std::ops::ControlFlow; /// Defines the `TermsContext` basically houses an arena where we can @@ -56,9 +56,7 @@ fn variances_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Variance] { let crate_map = tcx.crate_variances(()); return crate_map.variances.get(&item_def_id.to_def_id()).copied().unwrap_or(&[]); } - DefKind::TyAlias { lazy } - if lazy || tcx.type_of(item_def_id).instantiate_identity().has_opaque_types() => - { + DefKind::TyAlias if tcx.type_alias_is_lazy(item_def_id) => { // These are inferred. let crate_map = tcx.crate_variances(()); return crate_map.variances.get(&item_def_id.to_def_id()).copied().unwrap_or(&[]); @@ -129,7 +127,15 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc // By default, RPIT are invariant wrt type and const generics, but they are bivariant wrt // lifetime generics. - let mut variances: Vec<_> = std::iter::repeat(ty::Invariant).take(generics.count()).collect(); + let variances = std::iter::repeat(ty::Invariant).take(generics.count()); + + let mut variances: Vec<_> = match tcx.opaque_type_origin(item_def_id) { + rustc_hir::OpaqueTyOrigin::FnReturn(_) | rustc_hir::OpaqueTyOrigin::AsyncFn(_) => { + variances.collect() + } + // But TAIT are invariant for all generics + rustc_hir::OpaqueTyOrigin::TyAlias { .. } => return tcx.arena.alloc_from_iter(variances), + }; // Mark all lifetimes from parent generics as unused (Bivariant). // This will be overridden later if required. diff --git a/compiler/rustc_hir_analysis/src/variance/terms.rs b/compiler/rustc_hir_analysis/src/variance/terms.rs index 1a8ec5f08..275df2495 100644 --- a/compiler/rustc_hir_analysis/src/variance/terms.rs +++ b/compiler/rustc_hir_analysis/src/variance/terms.rs @@ -12,7 +12,7 @@ use rustc_arena::DroplessArena; use rustc_hir::def::DefKind; use rustc_hir::def_id::{LocalDefId, LocalDefIdMap}; -use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt}; +use rustc_middle::ty::{self, TyCtxt}; use std::fmt; use self::VarianceTerm::*; @@ -97,9 +97,7 @@ pub fn determine_parameters_to_be_inferred<'a, 'tcx>( } } DefKind::Fn | DefKind::AssocFn => terms_cx.add_inferreds_for_item(def_id), - DefKind::TyAlias { lazy } - if lazy || tcx.type_of(def_id).instantiate_identity().has_opaque_types() => - { + DefKind::TyAlias if tcx.type_alias_is_lazy(def_id) => { terms_cx.add_inferreds_for_item(def_id) } _ => {} diff --git a/compiler/rustc_hir_analysis/src/variance/test.rs b/compiler/rustc_hir_analysis/src/variance/test.rs index d57d05d76..d98dc0e6b 100644 --- a/compiler/rustc_hir_analysis/src/variance/test.rs +++ b/compiler/rustc_hir_analysis/src/variance/test.rs @@ -1,9 +1,24 @@ +use rustc_hir::def::DefKind; +use rustc_hir::def_id::CRATE_DEF_ID; use rustc_middle::ty::TyCtxt; use rustc_span::symbol::sym; use crate::errors; pub fn test_variance(tcx: TyCtxt<'_>) { + if tcx.has_attr(CRATE_DEF_ID, sym::rustc_variance_of_opaques) { + for id in tcx.hir().items() { + if matches!(tcx.def_kind(id.owner_id), DefKind::OpaqueTy) { + let variances_of = tcx.variances_of(id.owner_id); + + tcx.sess.emit_err(errors::VariancesOf { + span: tcx.def_span(id.owner_id), + variances_of: format!("{variances_of:?}"), + }); + } + } + } + // For unit testing: check for a special "rustc_variance" // attribute and report an error with various results if found. for id in tcx.hir().items() { |