Rollup merge of rust-lang#123016 - compiler-errors:no-type-var-origin…

…, r=lcnr

Remove `TypeVariableOriginKind` and `ConstVariableOriginKind`

It's annoying to have to import `TypeVariableOriginKind` just to fill it with `MiscVariable` for almost every use. Every other usage other than `TypeParameterDefinition` wasn't even used -- I can see how it may have been useful once for debugging, but I do quite a lot of typeck debugging and I've never really needed it.

So let's just remove it, and keep around the only useful thing which is the `DefId` of the param for `var_for_def`.

This is based on rust-lang#123006, which removed the special use of `TypeVariableOriginKind::OpaqueInference`, which I'm pretty sure I was the one that added.

r? lcnr or re-roll to types

compiler/rustc_borrowck/src/type_check/input_output.rs

@@ -11,7 +11,7 @@ use std::assert_matches::assert_matches;
 
 use itertools::Itertools;
 use rustc_hir as hir;
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_infer::infer::{BoundRegionConversionTime, RegionVariableOrigin};
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty};
@@ -75,10 +75,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             );
 
             let next_ty_var = || {
-                self.infcx.next_ty_var(TypeVariableOrigin {
-                    span: body.span,
-                    kind: TypeVariableOriginKind::MiscVariable,
-                })
+                self.infcx.next_ty_var(TypeVariableOrigin { span: body.span, param_def_id: None })
             };
             let output_ty = Ty::new_coroutine(
                 self.tcx(),

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -16,7 +16,7 @@ use rustc_index::{IndexSlice, IndexVec};
 use rustc_infer::infer::canonical::QueryRegionConstraints;
 use rustc_infer::infer::outlives::env::RegionBoundPairs;
 use rustc_infer::infer::region_constraints::RegionConstraintData;
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_infer::infer::{
     BoundRegion, BoundRegionConversionTime, InferCtxt, NllRegionVariableOrigin,
 };
@@ -2425,7 +2425,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     ty::RawPtr(_, _) | ty::FnPtr(_) => {
                         let ty_right = right.ty(body, tcx);
                         let common_ty = self.infcx.next_ty_var(TypeVariableOrigin {
-                            kind: TypeVariableOriginKind::MiscVariable,
+                            param_def_id: None,
                             span: body.source_info(location).span,
                         });
                         self.sub_types(

compiler/rustc_borrowck/src/type_check/relate_tys.rs

@@ -1,6 +1,6 @@
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::ErrorGuaranteed;
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_infer::infer::NllRegionVariableOrigin;
 use rustc_infer::infer::{ObligationEmittingRelation, StructurallyRelateAliases};
 use rustc_infer::traits::{Obligation, PredicateObligations};
@@ -129,10 +129,7 @@ impl<'me, 'bccx, 'tcx> NllTypeRelating<'me, 'bccx, 'tcx> {
         // the opaque.
         let mut enable_subtyping = |ty, opaque_is_expected| {
             let ty_vid = infcx.next_ty_var_id_in_universe(
-                TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::MiscVariable,
-                    span: self.span(),
-                },
+                TypeVariableOrigin { param_def_id: None, span: self.span() },
                 ty::UniverseIndex::ROOT,
             );
 

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -9,7 +9,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit;
 use rustc_hir::{GenericParamKind, ImplItemKind};
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_infer::infer::{self, InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::{util, FulfillmentError};
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
@@ -800,10 +800,10 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ImplTraitInTraitCollector<'_, 'tcx> {
                 bug!("FIXME(RPITIT): error here");
             }
             // Replace with infer var
-            let infer_ty = self.ocx.infcx.next_ty_var(TypeVariableOrigin {
-                span: self.span,
-                kind: TypeVariableOriginKind::MiscVariable,
-            });
+            let infer_ty = self
+                .ocx
+                .infcx
+                .next_ty_var(TypeVariableOrigin { span: self.span, param_def_id: None });
             self.types.insert(proj.def_id, (infer_ty, proj.args));
             // Recurse into bounds
             for (pred, pred_span) in self

compiler/rustc_hir_typeck/src/_match.rs

@@ -5,7 +5,7 @@ use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::{self as hir, ExprKind, PatKind};
 use rustc_hir_pretty::ty_to_string;
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::Span;
 use rustc_trait_selection::traits::{
@@ -67,10 +67,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // arm for inconsistent arms or to the whole match when a `()` type
                 // is required).
                 Expectation::ExpectHasType(ety) if ety != Ty::new_unit(self.tcx) => ety,
-                _ => self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::MiscVariable,
-                    span: expr.span,
-                }),
+                _ => self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr.span }),
             };
             CoerceMany::with_coercion_sites(coerce_first, arms)
         };
@@ -578,10 +575,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // ...but otherwise we want to use any supertype of the
             // scrutinee. This is sort of a workaround, see note (*) in
             // `check_pat` for some details.
-            let scrut_ty = self.next_ty_var(TypeVariableOrigin {
-                kind: TypeVariableOriginKind::TypeInference,
-                span: scrut.span,
-            });
+            let scrut_ty =
+                self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: scrut.span });
             self.check_expr_has_type_or_error(scrut, scrut_ty, |_| {});
             scrut_ty
         }

compiler/rustc_hir_typeck/src/callee.rs

@@ -13,10 +13,7 @@ use rustc_infer::{
     infer,
     traits::{self, Obligation},
 };
-use rustc_infer::{
-    infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind},
-    traits::ObligationCause,
-};
+use rustc_infer::{infer::type_variable::TypeVariableOrigin, traits::ObligationCause};
 use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability,
 };
@@ -180,18 +177,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     infer::FnCall,
                     closure_args.coroutine_closure_sig(),
                 );
-                let tupled_upvars_ty = self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::TypeInference,
-                    span: callee_expr.span,
-                });
+                let tupled_upvars_ty = self
+                    .next_ty_var(TypeVariableOrigin { param_def_id: None, span: callee_expr.span });
                 // We may actually receive a coroutine back whose kind is different
                 // from the closure that this dispatched from. This is because when
                 // we have no captures, we automatically implement `FnOnce`. This
                 // impl forces the closure kind to `FnOnce` i.e. `u8`.
-                let kind_ty = self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::TypeInference,
-                    span: callee_expr.span,
-                });
+                let kind_ty = self
+                    .next_ty_var(TypeVariableOrigin { param_def_id: None, span: callee_expr.span });
                 let call_sig = self.tcx.mk_fn_sig(
                     [coroutine_closure_sig.tupled_inputs_ty],
                     coroutine_closure_sig.to_coroutine(
@@ -305,10 +298,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 Ty::new_tup_from_iter(
                     self.tcx,
                     arg_exprs.iter().map(|e| {
-                        self.next_ty_var(TypeVariableOrigin {
-                            kind: TypeVariableOriginKind::TypeInference,
-                            span: e.span,
-                        })
+                        self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: e.span })
                     }),
                 )
             });

compiler/rustc_hir_typeck/src/check.rs

@@ -8,7 +8,7 @@ use rustc_hir::def::DefKind;
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir_analysis::check::{check_function_signature, forbid_intrinsic_abi};
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_infer::infer::RegionVariableOrigin;
 use rustc_middle::ty::{self, Binder, Ty, TyCtxt};
 use rustc_span::def_id::LocalDefId;
@@ -123,8 +123,7 @@ pub(super) fn check_fn<'a, 'tcx>(
         // We have special-cased the case where the function is declared
         // `-> dyn Foo` and we don't actually relate it to the
         // `fcx.ret_coercion`, so just instantiate a type variable.
-        actual_return_ty =
-            fcx.next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::DynReturnFn, span });
+        actual_return_ty = fcx.next_ty_var(TypeVariableOrigin { param_def_id: None, span });
         debug!("actual_return_ty replaced with {:?}", actual_return_ty);
     }
 

compiler/rustc_hir_typeck/src/closure.rs

@@ -6,7 +6,7 @@ use rustc_errors::ErrorGuaranteed;
 use rustc_hir as hir;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir_analysis::hir_ty_lowering::HirTyLowerer;
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_infer::infer::{BoundRegionConversionTime, DefineOpaqueTypes};
 use rustc_infer::infer::{InferOk, InferResult};
 use rustc_macros::{TypeFoldable, TypeVisitable};
@@ -72,10 +72,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let parent_args =
             GenericArgs::identity_for_item(tcx, tcx.typeck_root_def_id(expr_def_id.to_def_id()));
 
-        let tupled_upvars_ty = self.next_ty_var(TypeVariableOrigin {
-            kind: TypeVariableOriginKind::ClosureSynthetic,
-            span: expr_span,
-        });
+        let tupled_upvars_ty =
+            self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span });
 
         // FIXME: We could probably actually just unify this further --
         // instead of having a `FnSig` and a `Option<CoroutineTypes>`,
@@ -102,11 +100,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     // Create a type variable (for now) to represent the closure kind.
                     // It will be unified during the upvar inference phase (`upvar.rs`)
-                    None => self.next_ty_var(TypeVariableOrigin {
-                        // FIXME(eddyb) distinguish closure kind inference variables from the rest.
-                        kind: TypeVariableOriginKind::ClosureSynthetic,
-                        span: expr_span,
-                    }),
+                    None => {
+                        self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span })
+                    }
                 };
 
                 let closure_args = ty::ClosureArgs::new(
@@ -126,7 +122,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     hir::CoroutineKind::Desugared(hir::CoroutineDesugaring::Gen, _)
                     | hir::CoroutineKind::Coroutine(_) => {
                         let yield_ty = self.next_ty_var(TypeVariableOrigin {
-                            kind: TypeVariableOriginKind::ClosureSynthetic,
+                            param_def_id: None,
                             span: expr_span,
                         });
                         self.require_type_is_sized(yield_ty, expr_span, traits::SizedYieldType);
@@ -138,7 +134,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // not a problem.
                     hir::CoroutineKind::Desugared(hir::CoroutineDesugaring::AsyncGen, _) => {
                         let yield_ty = self.next_ty_var(TypeVariableOrigin {
-                            kind: TypeVariableOriginKind::ClosureSynthetic,
+                            param_def_id: None,
                             span: expr_span,
                         });
                         self.require_type_is_sized(yield_ty, expr_span, traits::SizedYieldType);
@@ -166,10 +162,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // Resume type defaults to `()` if the coroutine has no argument.
                 let resume_ty = liberated_sig.inputs().get(0).copied().unwrap_or(tcx.types.unit);
 
-                let interior = self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::ClosureSynthetic,
-                    span: expr_span,
-                });
+                let interior =
+                    self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span });
                 self.deferred_coroutine_interiors.borrow_mut().push((
                     expr_def_id,
                     body.id(),
@@ -181,11 +175,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // later during upvar analysis. Regular coroutines always have the kind
                 // ty of `().`
                 let kind_ty = match kind {
-                    hir::CoroutineKind::Desugared(_, hir::CoroutineSource::Closure) => self
-                        .next_ty_var(TypeVariableOrigin {
-                            kind: TypeVariableOriginKind::ClosureSynthetic,
-                            span: expr_span,
-                        }),
+                    hir::CoroutineKind::Desugared(_, hir::CoroutineSource::Closure) => {
+                        self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span })
+                    }
                     _ => tcx.types.unit,
                 };
 
@@ -219,30 +211,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                 };
                 // Compute all of the variables that will be used to populate the coroutine.
-                let resume_ty = self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::ClosureSynthetic,
-                    span: expr_span,
-                });
-                let interior = self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::ClosureSynthetic,
-                    span: expr_span,
-                });
+                let resume_ty =
+                    self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span });
+                let interior =
+                    self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span });
 
                 let closure_kind_ty = match expected_kind {
                     Some(kind) => Ty::from_closure_kind(tcx, kind),
 
                     // Create a type variable (for now) to represent the closure kind.
                     // It will be unified during the upvar inference phase (`upvar.rs`)
-                    None => self.next_ty_var(TypeVariableOrigin {
-                        kind: TypeVariableOriginKind::ClosureSynthetic,
-                        span: expr_span,
-                    }),
+                    None => {
+                        self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span })
+                    }
                 };
 
-                let coroutine_captures_by_ref_ty = self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::ClosureSynthetic,
-                    span: expr_span,
-                });
+                let coroutine_captures_by_ref_ty =
+                    self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span });
                 let closure_args = ty::CoroutineClosureArgs::new(
                     tcx,
                     ty::CoroutineClosureArgsParts {
@@ -274,16 +259,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     // Create a type variable (for now) to represent the closure kind.
                     // It will be unified during the upvar inference phase (`upvar.rs`)
-                    None => self.next_ty_var(TypeVariableOrigin {
-                        kind: TypeVariableOriginKind::ClosureSynthetic,
-                        span: expr_span,
-                    }),
+                    None => {
+                        self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span })
+                    }
                 };
 
-                let coroutine_upvars_ty = self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::ClosureSynthetic,
-                    span: expr_span,
-                });
+                let coroutine_upvars_ty =
+                    self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span });
 
                 // We need to turn the liberated signature that we got from HIR, which
                 // looks something like `|Args...| -> T`, into a signature that is suitable

compiler/rustc_hir_typeck/src/coercion.rs

@@ -43,7 +43,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::Expr;
 use rustc_hir_analysis::hir_ty_lowering::HirTyLowerer;
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_infer::infer::{Coercion, DefineOpaqueTypes, InferOk, InferResult};
 use rustc_infer::traits::TraitEngineExt as _;
 use rustc_infer::traits::{IfExpressionCause, MatchExpressionArmCause, TraitEngine};
@@ -279,10 +279,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         if b.is_ty_var() {
             // Two unresolved type variables: create a `Coerce` predicate.
             let target_ty = if self.use_lub {
-                self.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::LatticeVariable,
-                    span: self.cause.span,
-                })
+                self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: self.cause.span })
             } else {
                 b
             };
@@ -581,10 +578,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         // the `CoerceUnsized` target type and the expected type.
         // We only have the latter, so we use an inference variable
         // for the former and let type inference do the rest.
-        let origin = TypeVariableOrigin {
-            kind: TypeVariableOriginKind::MiscVariable,
-            span: self.cause.span,
-        };
+        let origin = TypeVariableOrigin { param_def_id: None, span: self.cause.span };
         let coerce_target = self.next_ty_var(origin);
         let mut coercion = self.unify_and(coerce_target, target, |target| {
             let unsize = Adjustment { kind: Adjust::Pointer(PointerCoercion::Unsize), target };

compiler/rustc_hir_typeck/src/demand.rs

@@ -337,10 +337,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ty_op: |ty| {
                 if let ty::Infer(infer) = ty.kind() {
                     match infer {
-                        ty::TyVar(_) => self.next_ty_var(TypeVariableOrigin {
-                            kind: TypeVariableOriginKind::MiscVariable,
-                            span: DUMMY_SP,
-                        }),
+                        ty::TyVar(_) => self
+                            .next_ty_var(TypeVariableOrigin { param_def_id: None, span: DUMMY_SP }),
                         ty::IntVar(_) => self.next_int_var(),
                         ty::FloatVar(_) => self.next_float_var(),
                         ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_) => {
@@ -356,10 +354,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 if let ty::ConstKind::Infer(_) = ct.kind() {
                     self.next_const_var(
                         ct.ty(),
-                        ConstVariableOrigin {
-                            kind: ConstVariableOriginKind::MiscVariable,
-                            span: DUMMY_SP,
-                        },
+                        ConstVariableOrigin { param_def_id: None, span: DUMMY_SP },
                     )
                 } else {
                     ct