diff --git a/compiler/rustc_typeck/src/astconv/generics.rs b/compiler/rustc_typeck/src/astconv/generics.rs index 3bfb2d3f1b0..301ede66006 100644 --- a/compiler/rustc_typeck/src/astconv/generics.rs +++ b/compiler/rustc_typeck/src/astconv/generics.rs @@ -1,12 +1,13 @@ use crate::astconv::{ - AstConv, ExplicitLateBound, GenericArgCountMismatch, GenericArgCountResult, GenericArgPosition, + AstConv, CreateSubstsForGenericArgsCtxt, ExplicitLateBound, GenericArgCountMismatch, + GenericArgCountResult, GenericArgPosition, }; use crate::errors::AssocTypeBindingNotAllowed; use rustc_ast::ast::ParamKindOrd; use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticId, ErrorReported}; use rustc_hir as hir; use rustc_hir::def_id::DefId; -use rustc_hir::{GenericArg, GenericArgs}; +use rustc_hir::GenericArg; use rustc_middle::ty::{ self, subst, subst::SubstsRef, GenericParamDef, GenericParamDefKind, Ty, TyCtxt, }; @@ -90,20 +91,14 @@ fn generic_arg_mismatch_err( /// instantiate a `GenericArg`. /// - `inferred_kind`: if no parameter was provided, and inference is enabled, then /// creates a suitable inference variable. - pub fn create_substs_for_generic_args<'b>( + pub fn create_substs_for_generic_args<'a>( tcx: TyCtxt<'tcx>, def_id: DefId, parent_substs: &[subst::GenericArg<'tcx>], has_self: bool, self_ty: Option>, arg_count: GenericArgCountResult, - args_for_def_id: impl Fn(DefId) -> (Option<&'b GenericArgs<'b>>, bool), - mut provided_kind: impl FnMut(&GenericParamDef, &GenericArg<'_>) -> subst::GenericArg<'tcx>, - mut inferred_kind: impl FnMut( - Option<&[subst::GenericArg<'tcx>]>, - &GenericParamDef, - bool, - ) -> subst::GenericArg<'tcx>, + ctx: &mut impl CreateSubstsForGenericArgsCtxt<'a, 'tcx>, ) -> SubstsRef<'tcx> { // Collect the segments of the path; we need to substitute arguments // for parameters throughout the entire path (wherever there are @@ -142,7 +137,7 @@ pub fn create_substs_for_generic_args<'b>( substs.push( self_ty .map(|ty| ty.into()) - .unwrap_or_else(|| inferred_kind(None, param, true)), + .unwrap_or_else(|| ctx.inferred_kind(None, param, true)), ); params.next(); } @@ -151,7 +146,7 @@ pub fn create_substs_for_generic_args<'b>( } // Check whether this segment takes generic arguments and the user has provided any. - let (generic_args, infer_args) = args_for_def_id(def_id); + let (generic_args, infer_args) = ctx.args_for_def_id(def_id); let mut args = generic_args.iter().flat_map(|generic_args| generic_args.args.iter()).peekable(); @@ -173,7 +168,7 @@ pub fn create_substs_for_generic_args<'b>( (GenericArg::Lifetime(_), GenericParamDefKind::Lifetime, _) | (GenericArg::Type(_), GenericParamDefKind::Type { .. }, _) | (GenericArg::Const(_), GenericParamDefKind::Const, _) => { - substs.push(provided_kind(param, arg)); + substs.push(ctx.provided_kind(param, arg)); args.next(); params.next(); } @@ -184,7 +179,7 @@ pub fn create_substs_for_generic_args<'b>( ) => { // We expected a lifetime argument, but got a type or const // argument. That means we're inferring the lifetimes. - substs.push(inferred_kind(None, param, infer_args)); + substs.push(ctx.inferred_kind(None, param, infer_args)); force_infer_lt = Some(arg); params.next(); } @@ -302,7 +297,7 @@ pub fn create_substs_for_generic_args<'b>( (None, Some(¶m)) => { // If there are fewer arguments than parameters, it means // we're inferring the remaining arguments. - substs.push(inferred_kind(Some(&substs), param, infer_args)); + substs.push(ctx.inferred_kind(Some(&substs), param, infer_args)); params.next(); } diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs index 07e523af3eb..89c5adfa14c 100644 --- a/compiler/rustc_typeck/src/astconv/mod.rs +++ b/compiler/rustc_typeck/src/astconv/mod.rs @@ -165,6 +165,23 @@ pub struct GenericArgCountResult { pub correct: Result<(), GenericArgCountMismatch>, } +pub trait CreateSubstsForGenericArgsCtxt<'a, 'tcx> { + fn args_for_def_id(&mut self, def_id: DefId) -> (Option<&'a GenericArgs<'a>>, bool); + + fn provided_kind( + &mut self, + param: &ty::GenericParamDef, + arg: &GenericArg<'_>, + ) -> subst::GenericArg<'tcx>; + + fn inferred_kind( + &mut self, + substs: Option<&[subst::GenericArg<'tcx>]>, + param: &ty::GenericParamDef, + infer_args: bool, + ) -> subst::GenericArg<'tcx>; +} + impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { pub fn ast_region_to_region( &self, @@ -321,81 +338,102 @@ fn create_substs_for_ast_path<'a>( ); let is_object = self_ty.map_or(false, |ty| ty == self.tcx().types.trait_object_dummy_self); - let default_needs_object_self = |param: &ty::GenericParamDef| { - if let GenericParamDefKind::Type { has_default, .. } = param.kind { - if is_object && has_default { - let default_ty = tcx.at(span).type_of(param.def_id); - let self_param = tcx.types.self_param; - if default_ty.walk().any(|arg| arg == self_param.into()) { - // There is no suitable inference default for a type parameter - // that references self, in an object type. - return true; + + struct SubstsForAstPathCtxt<'a, 'tcx> { + astconv: &'a (dyn AstConv<'tcx> + 'a), + def_id: DefId, + generic_args: &'a GenericArgs<'a>, + span: Span, + missing_type_params: Vec, + inferred_params: Vec, + infer_args: bool, + is_object: bool, + } + + impl<'tcx, 'a> SubstsForAstPathCtxt<'tcx, 'a> { + fn default_needs_object_self(&mut self, param: &ty::GenericParamDef) -> bool { + let tcx = self.astconv.tcx(); + if let GenericParamDefKind::Type { has_default, .. } = param.kind { + if self.is_object && has_default { + let default_ty = tcx.at(self.span).type_of(param.def_id); + let self_param = tcx.types.self_param; + if default_ty.walk().any(|arg| arg == self_param.into()) { + // There is no suitable inference default for a type parameter + // that references self, in an object type. + return true; + } } } + + false } + } - false - }; - - let mut missing_type_params = vec![]; - let mut inferred_params = vec![]; - let substs = Self::create_substs_for_generic_args( - tcx, - def_id, - parent_substs, - self_ty.is_some(), - self_ty, - arg_count.clone(), - // Provide the generic args, and whether types should be inferred. - |did| { - if did == def_id { - (Some(generic_args), infer_args) + impl<'a, 'tcx> CreateSubstsForGenericArgsCtxt<'a, 'tcx> for SubstsForAstPathCtxt<'a, 'tcx> { + fn args_for_def_id(&mut self, did: DefId) -> (Option<&'a GenericArgs<'a>>, bool) { + if did == self.def_id { + (Some(self.generic_args), self.infer_args) } else { // The last component of this tuple is unimportant. (None, false) } - }, - // Provide substitutions for parameters for which (valid) arguments have been provided. - |param, arg| match (¶m.kind, arg) { - (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => { - self.ast_region_to_region(<, Some(param)).into() - } - (GenericParamDefKind::Type { has_default, .. }, GenericArg::Type(ty)) => { - if *has_default { - tcx.check_optional_stability( - param.def_id, - Some(arg.id()), - arg.span(), - |_, _| { - // Default generic parameters may not be marked - // with stability attributes, i.e. when the - // default parameter was defined at the same time - // as the rest of the type. As such, we ignore missing - // stability attributes. + } + + fn provided_kind( + &mut self, + param: &ty::GenericParamDef, + arg: &GenericArg<'_>, + ) -> subst::GenericArg<'tcx> { + let tcx = self.astconv.tcx(); + match (¶m.kind, arg) { + (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => { + self.astconv.ast_region_to_region(<, Some(param)).into() + } + (&GenericParamDefKind::Type { has_default, .. }, GenericArg::Type(ty)) => { + if has_default { + tcx.check_optional_stability( + param.def_id, + Some(arg.id()), + arg.span(), + |_, _| { + // Default generic parameters may not be marked + // with stability attributes, i.e. when the + // default parameter was defined at the same time + // as the rest of the type. As such, we ignore missing + // stability attributes. + }, + ) + } + if let (hir::TyKind::Infer, false) = + (&ty.kind, self.astconv.allow_ty_infer()) + { + self.inferred_params.push(ty.span); + tcx.ty_error().into() + } else { + self.astconv.ast_ty_to_ty(&ty).into() + } + } + (GenericParamDefKind::Const, GenericArg::Const(ct)) => { + ty::Const::from_opt_const_arg_anon_const( + tcx, + ty::WithOptConstParam { + did: tcx.hir().local_def_id(ct.value.hir_id), + const_param_did: Some(param.def_id), }, ) + .into() } - if let (hir::TyKind::Infer, false) = (&ty.kind, self.allow_ty_infer()) { - inferred_params.push(ty.span); - tcx.ty_error().into() - } else { - self.ast_ty_to_ty(&ty).into() - } + _ => unreachable!(), } - (GenericParamDefKind::Const, GenericArg::Const(ct)) => { - ty::Const::from_opt_const_arg_anon_const( - tcx, - ty::WithOptConstParam { - did: tcx.hir().local_def_id(ct.value.hir_id), - const_param_did: Some(param.def_id), - }, - ) - .into() - } - _ => unreachable!(), - }, - // Provide substitutions for parameters for which arguments are inferred. - |substs, param, infer_args| { + } + + fn inferred_kind( + &mut self, + substs: Option<&[subst::GenericArg<'tcx>]>, + param: &ty::GenericParamDef, + infer_args: bool, + ) -> subst::GenericArg<'tcx> { + let tcx = self.astconv.tcx(); match param.kind { GenericParamDefKind::Lifetime => tcx.lifetimes.re_static.into(), GenericParamDefKind::Type { has_default, .. } => { @@ -407,48 +445,72 @@ fn create_substs_for_ast_path<'a>( // other type parameters may reference `Self` in their // defaults. This will lead to an ICE if we are not // careful! - if default_needs_object_self(param) { - missing_type_params.push(param.name.to_string()); + if self.default_needs_object_self(param) { + self.missing_type_params.push(param.name.to_string()); tcx.ty_error().into() } else { // This is a default type parameter. - self.normalize_ty( - span, - tcx.at(span).type_of(param.def_id).subst_spanned( - tcx, - substs.unwrap(), - Some(span), - ), - ) - .into() + self.astconv + .normalize_ty( + self.span, + tcx.at(self.span).type_of(param.def_id).subst_spanned( + tcx, + substs.unwrap(), + Some(self.span), + ), + ) + .into() } } else if infer_args { // No type parameters were provided, we can infer all. - let param = - if !default_needs_object_self(param) { Some(param) } else { None }; - self.ty_infer(param, span).into() + let param = if !self.default_needs_object_self(param) { + Some(param) + } else { + None + }; + self.astconv.ty_infer(param, self.span).into() } else { // We've already errored above about the mismatch. tcx.ty_error().into() } } GenericParamDefKind::Const => { - let ty = tcx.at(span).type_of(param.def_id); + let ty = tcx.at(self.span).type_of(param.def_id); // FIXME(const_generics:defaults) if infer_args { // No const parameters were provided, we can infer all. - self.ct_infer(ty, Some(param), span).into() + self.astconv.ct_infer(ty, Some(param), self.span).into() } else { // We've already errored above about the mismatch. tcx.const_error(ty).into() } } } - }, + } + } + + let mut substs_ctx = SubstsForAstPathCtxt { + astconv: self, + def_id, + span, + generic_args, + missing_type_params: vec![], + inferred_params: vec![], + infer_args, + is_object, + }; + let substs = Self::create_substs_for_generic_args( + tcx, + def_id, + parent_substs, + self_ty.is_some(), + self_ty, + arg_count.clone(), + &mut substs_ctx, ); self.complain_about_missing_type_params( - missing_type_params, + substs_ctx.missing_type_params, def_id, span, generic_args.args.is_empty(), diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs index 0bb7b464f16..300ee8f85f8 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs @@ -1,5 +1,6 @@ use crate::astconv::{ - AstConv, ExplicitLateBound, GenericArgCountMismatch, GenericArgCountResult, PathSeg, + AstConv, CreateSubstsForGenericArgsCtxt, ExplicitLateBound, GenericArgCountMismatch, + GenericArgCountResult, PathSeg, }; use crate::check::callee::{self, DeferredCallResolution}; use crate::check::method::{self, MethodCallee, SelfSource}; @@ -1298,6 +1299,94 @@ pub fn instantiate_value_path( }, }; + struct CreateCtorSubstsContext<'a, 'tcx> { + fcx: &'a FnCtxt<'a, 'tcx>, + span: Span, + path_segs: &'a [PathSeg], + infer_args_for_err: &'a FxHashSet, + segments: &'a [hir::PathSegment<'a>], + } + impl<'tcx, 'a> CreateSubstsForGenericArgsCtxt<'a, 'tcx> for CreateCtorSubstsContext<'a, 'tcx> { + fn args_for_def_id( + &mut self, + def_id: DefId, + ) -> (Option<&'a hir::GenericArgs<'a>>, bool) { + if let Some(&PathSeg(_, index)) = + self.path_segs.iter().find(|&PathSeg(did, _)| *did == def_id) + { + // If we've encountered an `impl Trait`-related error, we're just + // going to infer the arguments for better error messages. + if !self.infer_args_for_err.contains(&index) { + // Check whether the user has provided generic arguments. + if let Some(ref data) = self.segments[index].args { + return (Some(data), self.segments[index].infer_args); + } + } + return (None, self.segments[index].infer_args); + } + + (None, true) + } + + fn provided_kind( + &mut self, + param: &ty::GenericParamDef, + arg: &GenericArg<'_>, + ) -> subst::GenericArg<'tcx> { + match (¶m.kind, arg) { + (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => { + AstConv::ast_region_to_region(self.fcx, lt, Some(param)).into() + } + (GenericParamDefKind::Type { .. }, GenericArg::Type(ty)) => { + self.fcx.to_ty(ty).into() + } + (GenericParamDefKind::Const, GenericArg::Const(ct)) => { + self.fcx.const_arg_to_const(&ct.value, param.def_id).into() + } + _ => unreachable!(), + } + } + + fn inferred_kind( + &mut self, + substs: Option<&[subst::GenericArg<'tcx>]>, + param: &ty::GenericParamDef, + infer_args: bool, + ) -> subst::GenericArg<'tcx> { + let tcx = self.fcx.tcx(); + match param.kind { + GenericParamDefKind::Lifetime => { + self.fcx.re_infer(Some(param), self.span).unwrap().into() + } + GenericParamDefKind::Type { has_default, .. } => { + if !infer_args && has_default { + // If we have a default, then we it doesn't matter that we're not + // inferring the type arguments: we provide the default where any + // is missing. + let default = tcx.type_of(param.def_id); + self.fcx + .normalize_ty( + self.span, + default.subst_spanned(tcx, substs.unwrap(), Some(self.span)), + ) + .into() + } else { + // If no type arguments were provided, we have to infer them. + // This case also occurs as a result of some malformed input, e.g. + // a lifetime argument being given instead of a type parameter. + // Using inference instead of `Error` gives better error messages. + self.fcx.var_for_def(self.span, param) + } + } + GenericParamDefKind::Const => { + // FIXME(const_generics:defaults) + // No const parameters were provided, we have to infer them. + self.fcx.var_for_def(self.span, param) + } + } + } + } + let substs = self_ctor_substs.unwrap_or_else(|| { AstConv::create_substs_for_generic_args( tcx, @@ -1306,68 +1395,12 @@ pub fn instantiate_value_path( has_self, self_ty, arg_count, - // Provide the generic args, and whether types should be inferred. - |def_id| { - if let Some(&PathSeg(_, index)) = - path_segs.iter().find(|&PathSeg(did, _)| *did == def_id) - { - // If we've encountered an `impl Trait`-related error, we're just - // going to infer the arguments for better error messages. - if !infer_args_for_err.contains(&index) { - // Check whether the user has provided generic arguments. - if let Some(ref data) = segments[index].args { - return (Some(data), segments[index].infer_args); - } - } - return (None, segments[index].infer_args); - } - - (None, true) - }, - // Provide substitutions for parameters for which (valid) arguments have been provided. - |param, arg| match (¶m.kind, arg) { - (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => { - AstConv::ast_region_to_region(self, lt, Some(param)).into() - } - (GenericParamDefKind::Type { .. }, GenericArg::Type(ty)) => { - self.to_ty(ty).into() - } - (GenericParamDefKind::Const, GenericArg::Const(ct)) => { - self.const_arg_to_const(&ct.value, param.def_id).into() - } - _ => unreachable!(), - }, - // Provide substitutions for parameters for which arguments are inferred. - |substs, param, infer_args| { - match param.kind { - GenericParamDefKind::Lifetime => { - self.re_infer(Some(param), span).unwrap().into() - } - GenericParamDefKind::Type { has_default, .. } => { - if !infer_args && has_default { - // If we have a default, then we it doesn't matter that we're not - // inferring the type arguments: we provide the default where any - // is missing. - let default = tcx.type_of(param.def_id); - self.normalize_ty( - span, - default.subst_spanned(tcx, substs.unwrap(), Some(span)), - ) - .into() - } else { - // If no type arguments were provided, we have to infer them. - // This case also occurs as a result of some malformed input, e.g. - // a lifetime argument being given instead of a type parameter. - // Using inference instead of `Error` gives better error messages. - self.var_for_def(span, param) - } - } - GenericParamDefKind::Const => { - // FIXME(const_generics:defaults) - // No const parameters were provided, we have to infer them. - self.var_for_def(span, param) - } - } + &mut CreateCtorSubstsContext { + fcx: self, + span, + path_segs: &path_segs, + infer_args_for_err: &infer_args_for_err, + segments, }, ) }); diff --git a/compiler/rustc_typeck/src/check/method/confirm.rs b/compiler/rustc_typeck/src/check/method/confirm.rs index fd2700b85e2..fb048abc0e9 100644 --- a/compiler/rustc_typeck/src/check/method/confirm.rs +++ b/compiler/rustc_typeck/src/check/method/confirm.rs @@ -1,6 +1,6 @@ use super::{probe, MethodCallee}; -use crate::astconv::AstConv; +use crate::astconv::{AstConv, CreateSubstsForGenericArgsCtxt}; use crate::check::{callee, FnCtxt}; use crate::hir::def_id::DefId; use crate::hir::GenericArg; @@ -10,7 +10,7 @@ use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCast}; use rustc_middle::ty::adjustment::{AllowTwoPhase, AutoBorrow, AutoBorrowMutability}; use rustc_middle::ty::fold::TypeFoldable; -use rustc_middle::ty::subst::{Subst, SubstsRef}; +use rustc_middle::ty::subst::{self, Subst, SubstsRef}; use rustc_middle::ty::{self, GenericParamDefKind, Ty}; use rustc_span::Span; use rustc_trait_selection::traits; @@ -307,6 +307,52 @@ fn instantiate_method_substs( // parameters from the type and those from the method. assert_eq!(generics.parent_count, parent_substs.len()); + struct MethodSubstsCtxt<'a, 'tcx> { + cfcx: &'a ConfirmContext<'a, 'tcx>, + pick: &'a probe::Pick<'tcx>, + seg: &'a hir::PathSegment<'a>, + } + impl<'a, 'tcx> CreateSubstsForGenericArgsCtxt<'a, 'tcx> for MethodSubstsCtxt<'a, 'tcx> { + fn args_for_def_id( + &mut self, + def_id: DefId, + ) -> (Option<&'a hir::GenericArgs<'a>>, bool) { + if def_id == self.pick.item.def_id { + if let Some(ref data) = self.seg.args { + return (Some(data), false); + } + } + (None, false) + } + + fn provided_kind( + &mut self, + param: &ty::GenericParamDef, + arg: &GenericArg<'_>, + ) -> subst::GenericArg<'tcx> { + match (¶m.kind, arg) { + (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => { + AstConv::ast_region_to_region(self.cfcx.fcx, lt, Some(param)).into() + } + (GenericParamDefKind::Type { .. }, GenericArg::Type(ty)) => { + self.cfcx.to_ty(ty).into() + } + (GenericParamDefKind::Const, GenericArg::Const(ct)) => { + self.cfcx.const_arg_to_const(&ct.value, param.def_id).into() + } + _ => unreachable!(), + } + } + + fn inferred_kind( + &mut self, + _substs: Option<&[subst::GenericArg<'tcx>]>, + param: &ty::GenericParamDef, + _infer_args: bool, + ) -> subst::GenericArg<'tcx> { + self.cfcx.var_for_def(self.cfcx.span, param) + } + } AstConv::create_substs_for_generic_args( self.tcx, pick.item.def_id, @@ -314,29 +360,7 @@ fn instantiate_method_substs( false, None, arg_count_correct, - // Provide the generic args, and whether types should be inferred. - |def_id| { - // The last component of the returned tuple here is unimportant. - if def_id == pick.item.def_id { - if let Some(ref data) = seg.args { - return (Some(data), false); - } - } - (None, false) - }, - // Provide substitutions for parameters for which (valid) arguments have been provided. - |param, arg| match (¶m.kind, arg) { - (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => { - AstConv::ast_region_to_region(self.fcx, lt, Some(param)).into() - } - (GenericParamDefKind::Type { .. }, GenericArg::Type(ty)) => self.to_ty(ty).into(), - (GenericParamDefKind::Const, GenericArg::Const(ct)) => { - self.const_arg_to_const(&ct.value, param.def_id).into() - } - _ => unreachable!(), - }, - // Provide substitutions for parameters for which arguments are inferred. - |_, param, _| self.var_for_def(self.span, param), + &mut MethodSubstsCtxt { cfcx: self, pick, seg }, ) }