diff options
Diffstat (limited to 'compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs')
-rw-r--r-- | compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs | 421 |
1 files changed, 263 insertions, 158 deletions
diff --git a/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs b/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs index 561d1354e..7b3178e61 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs @@ -1,6 +1,12 @@ +use crate::errors::{ + AmbigousImpl, AmbigousReturn, AnnotationRequired, InferenceBadError, NeedTypeInfoInGenerator, + SourceKindMultiSuggestion, SourceKindSubdiag, +}; +use crate::infer::error_reporting::TypeErrCtxt; use crate::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use crate::infer::InferCtxt; -use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed}; +use rustc_errors::IntoDiagnostic; +use rustc_errors::{DiagnosticBuilder, ErrorGuaranteed, IntoDiagnosticArg}; use rustc_hir as hir; use rustc_hir::def::Res; use rustc_hir::def::{CtorOf, DefKind, Namespace}; @@ -11,8 +17,8 @@ use rustc_middle::hir::nested_filter; use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind}; use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability}; use rustc_middle::ty::print::{FmtPrinter, PrettyPrinter, Print, Printer}; -use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst, SubstsRef}; use rustc_middle::ty::{self, DefIdTree, InferConst}; +use rustc_middle::ty::{GenericArg, GenericArgKind, SubstsRef}; use rustc_middle::ty::{IsSuggestable, Ty, TyCtxt, TypeckResults}; use rustc_span::symbol::{kw, Ident}; use rustc_span::{BytePos, Span}; @@ -60,38 +66,49 @@ pub struct InferenceDiagnosticsParentData { name: String, } +#[derive(Clone)] pub enum UnderspecifiedArgKind { Type { prefix: Cow<'static, str> }, Const { is_parameter: bool }, } impl InferenceDiagnosticsData { - /// Generate a label for a generic argument which can't be inferred. When not - /// much is known about the argument, `use_diag` may be used to describe the - /// labeled value. - fn cannot_infer_msg(&self) -> String { - if self.name == "_" && matches!(self.kind, UnderspecifiedArgKind::Type { .. }) { - return "cannot infer type".to_string(); - } - - let suffix = match &self.parent { - Some(parent) => parent.suffix_string(), - None => String::new(), - }; - - // For example: "cannot infer type for type parameter `T`" - format!("cannot infer {} `{}`{}", self.kind.prefix_string(), self.name, suffix) + fn can_add_more_info(&self) -> bool { + !(self.name == "_" && matches!(self.kind, UnderspecifiedArgKind::Type { .. })) } - fn where_x_is_specified(&self, in_type: Ty<'_>) -> String { + fn where_x_is_kind(&self, in_type: Ty<'_>) -> &'static str { if in_type.is_ty_infer() { - String::new() + "empty" } else if self.name == "_" { // FIXME: Consider specializing this message if there is a single `_` // in the type. - ", where the placeholders `_` are specified".to_string() + "underscore" } else { - format!(", where the {} `{}` is specified", self.kind.prefix_string(), self.name) + "has_name" + } + } + + /// Generate a label for a generic argument which can't be inferred. When not + /// much is known about the argument, `use_diag` may be used to describe the + /// labeled value. + fn make_bad_error(&self, span: Span) -> InferenceBadError<'_> { + let has_parent = self.parent.is_some(); + let bad_kind = if self.can_add_more_info() { "more_info" } else { "other" }; + let (parent_prefix, parent_name) = self + .parent + .as_ref() + .map(|parent| (parent.prefix, parent.name.clone())) + .unwrap_or_default(); + InferenceBadError { + span, + bad_kind, + prefix_kind: self.kind.clone(), + prefix: self.kind.try_get_prefix().unwrap_or_default(), + name: self.name.clone(), + has_parent, + parent_prefix, + parent_name, } } } @@ -113,23 +130,29 @@ impl InferenceDiagnosticsParentData { fn for_def_id(tcx: TyCtxt<'_>, def_id: DefId) -> Option<InferenceDiagnosticsParentData> { Self::for_parent_def_id(tcx, tcx.parent(def_id)) } +} - fn suffix_string(&self) -> String { - format!(" declared on the {} `{}`", self.prefix, self.name) +impl IntoDiagnosticArg for UnderspecifiedArgKind { + fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> { + let kind = match self { + Self::Type { .. } => "type", + Self::Const { is_parameter: true } => "const_with_param", + Self::Const { is_parameter: false } => "const", + }; + rustc_errors::DiagnosticArgValue::Str(kind.into()) } } impl UnderspecifiedArgKind { - fn prefix_string(&self) -> Cow<'static, str> { + fn try_get_prefix(&self) -> Option<&str> { match self { - Self::Type { prefix } => format!("type for {}", prefix).into(), - Self::Const { is_parameter: true } => "the value of const parameter".into(), - Self::Const { is_parameter: false } => "the value of the constant".into(), + Self::Type { prefix } => Some(prefix.as_ref()), + Self::Const { .. } => None, } } } -fn fmt_printer<'a, 'tcx>(infcx: &'a InferCtxt<'_, 'tcx>, ns: Namespace) -> FmtPrinter<'a, 'tcx> { +fn fmt_printer<'a, 'tcx>(infcx: &'a InferCtxt<'tcx>, ns: Namespace) -> FmtPrinter<'a, 'tcx> { let mut printer = FmtPrinter::new(infcx.tcx, ns); let ty_getter = move |ty_vid| { if infcx.probe_ty_var(ty_vid).is_ok() { @@ -160,7 +183,7 @@ fn fmt_printer<'a, 'tcx>(infcx: &'a InferCtxt<'_, 'tcx>, ns: Namespace) -> FmtPr printer } -fn ty_to_string<'tcx>(infcx: &InferCtxt<'_, 'tcx>, ty: Ty<'tcx>) -> String { +fn ty_to_string<'tcx>(infcx: &InferCtxt<'tcx>, ty: Ty<'tcx>) -> String { let printer = fmt_printer(infcx, Namespace::TypeNS); let ty = infcx.resolve_vars_if_possible(ty); match ty.kind() { @@ -177,9 +200,9 @@ fn ty_to_string<'tcx>(infcx: &InferCtxt<'_, 'tcx>, ty: Ty<'tcx>) -> String { } /// We don't want to directly use `ty_to_string` for closures as their type isn't really -/// something users are familar with. Directly printing the `fn_sig` of closures also +/// something users are familiar with. Directly printing the `fn_sig` of closures also /// doesn't work as they actually use the "rust-call" API. -fn closure_as_fn_str<'tcx>(infcx: &InferCtxt<'_, 'tcx>, ty: Ty<'tcx>) -> String { +fn closure_as_fn_str<'tcx>(infcx: &InferCtxt<'tcx>, ty: Ty<'tcx>) -> String { let ty::Closure(_, substs) = ty.kind() else { unreachable!() }; let fn_sig = substs.as_closure().sig(); let args = fn_sig @@ -203,7 +226,7 @@ fn closure_as_fn_str<'tcx>(infcx: &InferCtxt<'_, 'tcx>, ty: Ty<'tcx>) -> String format!("fn({}){}", args, ret) } -impl<'a, 'tcx> InferCtxt<'a, 'tcx> { +impl<'tcx> InferCtxt<'tcx> { /// Extracts data used by diagnostic for either types or constants /// which were stuck during inference. pub fn extract_inference_diagnostics_data( @@ -295,7 +318,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { } } - /// Used as a fallback in [InferCtxt::emit_inference_failure_err] + /// Used as a fallback in [TypeErrCtxt::emit_inference_failure_err] /// in case we weren't able to get a better error. fn bad_inference_failure_err( &self, @@ -303,13 +326,48 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { arg_data: InferenceDiagnosticsData, error_code: TypeAnnotationNeeded, ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> { - let error_code = error_code.into(); - let mut err = - self.tcx.sess.struct_span_err_with_code(span, "type annotations needed", error_code); - err.span_label(span, arg_data.cannot_infer_msg()); - err + let source_kind = "other"; + let source_name = ""; + let failure_span = None; + let infer_subdiags = Vec::new(); + let multi_suggestions = Vec::new(); + let bad_label = Some(arg_data.make_bad_error(span)); + match error_code { + TypeAnnotationNeeded::E0282 => AnnotationRequired { + span, + source_kind, + source_name, + failure_span, + infer_subdiags, + multi_suggestions, + bad_label, + } + .into_diagnostic(&self.tcx.sess.parse_sess.span_diagnostic), + TypeAnnotationNeeded::E0283 => AmbigousImpl { + span, + source_kind, + source_name, + failure_span, + infer_subdiags, + multi_suggestions, + bad_label, + } + .into_diagnostic(&self.tcx.sess.parse_sess.span_diagnostic), + TypeAnnotationNeeded::E0284 => AmbigousReturn { + span, + source_kind, + source_name, + failure_span, + infer_subdiags, + multi_suggestions, + bad_label, + } + .into_diagnostic(&self.tcx.sess.parse_sess.span_diagnostic), + } } +} +impl<'tcx> TypeErrCtxt<'_, 'tcx> { pub fn emit_inference_failure_err( &self, body_id: Option<hir::BodyId>, @@ -321,14 +379,12 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { let arg = self.resolve_vars_if_possible(arg); let arg_data = self.extract_inference_diagnostics_data(arg, None); - let Some(typeck_results) = self.in_progress_typeck_results else { + let Some(typeck_results) = &self.typeck_results else { // If we don't have any typeck results we're outside // of a body, so we won't be able to get better info // here. return self.bad_inference_failure_err(failure_span, arg_data, error_code); }; - let typeck_results = typeck_results.borrow(); - let typeck_results = &typeck_results; let mut local_visitor = FindInferSourceVisitor::new(&self, typeck_results, arg); if let Some(body_id) = body_id { @@ -340,48 +396,39 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { return self.bad_inference_failure_err(failure_span, arg_data, error_code) }; - let error_code = error_code.into(); - let mut err = self.tcx.sess.struct_span_err_with_code( - span, - &format!("type annotations needed{}", kind.ty_msg(self)), - error_code, - ); - - if should_label_span && !failure_span.overlaps(span) { - err.span_label(failure_span, "type must be known at this point"); - } + let (source_kind, name) = kind.ty_localized_msg(self); + let failure_span = if should_label_span && !failure_span.overlaps(span) { + Some(failure_span) + } else { + None + }; + let mut infer_subdiags = Vec::new(); + let mut multi_suggestions = Vec::new(); match kind { InferSourceKind::LetBinding { insert_span, pattern_name, ty } => { - let suggestion_msg = if let Some(name) = pattern_name { - format!( - "consider giving `{}` an explicit type{}", - name, - arg_data.where_x_is_specified(ty) - ) - } else { - format!( - "consider giving this pattern a type{}", - arg_data.where_x_is_specified(ty) - ) - }; - err.span_suggestion_verbose( - insert_span, - &suggestion_msg, - format!(": {}", ty_to_string(self, ty)), - Applicability::HasPlaceholders, - ); + infer_subdiags.push(SourceKindSubdiag::LetLike { + span: insert_span, + name: pattern_name.map(|name| name.to_string()).unwrap_or_else(String::new), + x_kind: arg_data.where_x_is_kind(ty), + prefix_kind: arg_data.kind.clone(), + prefix: arg_data.kind.try_get_prefix().unwrap_or_default(), + arg_name: arg_data.name, + kind: if pattern_name.is_some() { "with_pattern" } else { "other" }, + type_name: ty_to_string(self, ty), + }); } InferSourceKind::ClosureArg { insert_span, ty } => { - err.span_suggestion_verbose( - insert_span, - &format!( - "consider giving this closure parameter an explicit type{}", - arg_data.where_x_is_specified(ty) - ), - format!(": {}", ty_to_string(self, ty)), - Applicability::HasPlaceholders, - ); + infer_subdiags.push(SourceKindSubdiag::LetLike { + span: insert_span, + name: String::new(), + x_kind: arg_data.where_x_is_kind(ty), + prefix_kind: arg_data.kind.clone(), + prefix: arg_data.kind.try_get_prefix().unwrap_or_default(), + arg_name: arg_data.name, + kind: "closure", + type_name: ty_to_string(self, ty), + }); } InferSourceKind::GenericArg { insert_span, @@ -389,23 +436,25 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { generics_def_id, def_id: _, generic_args, + have_turbofish, } => { let generics = self.tcx.generics_of(generics_def_id); let is_type = matches!(arg.unpack(), GenericArgKind::Type(_)); - let cannot_infer_msg = format!( - "cannot infer {} of the {} parameter `{}`{}", - if is_type { "type" } else { "the value" }, - if is_type { "type" } else { "const" }, - generics.params[argument_index].name, - // We use the `generics_def_id` here, as even when suggesting `None::<T>`, - // the type parameter `T` was still declared on the enum, not on the - // variant. + let (parent_exists, parent_prefix, parent_name) = InferenceDiagnosticsParentData::for_parent_def_id(self.tcx, generics_def_id) - .map_or(String::new(), |parent| parent.suffix_string()), - ); + .map_or((false, String::new(), String::new()), |parent| { + (true, parent.prefix.to_string(), parent.name) + }); - err.span_label(span, cannot_infer_msg); + infer_subdiags.push(SourceKindSubdiag::GenericLabel { + span, + is_type, + param_name: generics.params[argument_index].name.to_string(), + parent_exists, + parent_prefix, + parent_name, + }); let args = fmt_printer(self, Namespace::TypeNS) .comma_sep(generic_args.iter().copied().map(|arg| { @@ -435,15 +484,13 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { .unwrap() .into_buffer(); - err.span_suggestion_verbose( - insert_span, - &format!( - "consider specifying the generic argument{}", - pluralize!(generic_args.len()), - ), - format!("::<{}>", args), - Applicability::HasPlaceholders, - ); + if !have_turbofish { + infer_subdiags.push(SourceKindSubdiag::GenericSuggestion { + span: insert_span, + arg_count: generic_args.len(), + args, + }); + } } InferSourceKind::FullyQualifiedMethodCall { receiver, successor, substs, def_id } => { let printer = fmt_printer(self, Namespace::ValueNS); @@ -468,39 +515,58 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { _ => "", }; - let suggestion = vec![ - (receiver.span.shrink_to_lo(), format!("{def_path}({adjustment}")), - (receiver.span.shrink_to_hi().with_hi(successor.1), successor.0.to_string()), - ]; - err.multipart_suggestion_verbose( - "try using a fully qualified path to specify the expected types", - suggestion, - Applicability::HasPlaceholders, - ); + multi_suggestions.push(SourceKindMultiSuggestion::new_fully_qualified( + receiver.span, + def_path, + adjustment, + successor, + )); } InferSourceKind::ClosureReturn { ty, data, should_wrap_expr } => { - let ret = ty_to_string(self, ty); - let (arrow, post) = match data { - FnRetTy::DefaultReturn(_) => ("-> ", " "), - _ => ("", ""), - }; - let suggestion = match should_wrap_expr { - Some(end_span) => vec![ - (data.span(), format!("{}{}{}{{ ", arrow, ret, post)), - (end_span, " }".to_string()), - ], - None => vec![(data.span(), format!("{}{}{}", arrow, ret, post))], - }; - err.multipart_suggestion_verbose( - "try giving this closure an explicit return type", - suggestion, - Applicability::HasPlaceholders, - ); + let ty_info = ty_to_string(self, ty); + multi_suggestions.push(SourceKindMultiSuggestion::new_closure_return( + ty_info, + data, + should_wrap_expr, + )); } } - err + match error_code { + TypeAnnotationNeeded::E0282 => AnnotationRequired { + span, + source_kind, + source_name: &name, + failure_span, + infer_subdiags, + multi_suggestions, + bad_label: None, + } + .into_diagnostic(&self.tcx.sess.parse_sess.span_diagnostic), + TypeAnnotationNeeded::E0283 => AmbigousImpl { + span, + source_kind, + source_name: &name, + failure_span, + infer_subdiags, + multi_suggestions, + bad_label: None, + } + .into_diagnostic(&self.tcx.sess.parse_sess.span_diagnostic), + TypeAnnotationNeeded::E0284 => AmbigousReturn { + span, + source_kind, + source_name: &name, + failure_span, + infer_subdiags, + multi_suggestions, + bad_label: None, + } + .into_diagnostic(&self.tcx.sess.parse_sess.span_diagnostic), + } } +} +impl<'tcx> InferCtxt<'tcx> { pub fn need_type_info_err_in_generator( &self, kind: hir::GeneratorKind, @@ -510,15 +576,26 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { let ty = self.resolve_vars_if_possible(ty); let data = self.extract_inference_diagnostics_data(ty.into(), None); - let mut err = struct_span_err!( - self.tcx.sess, + NeedTypeInfoInGenerator { + bad_label: data.make_bad_error(span), span, - E0698, - "type inside {} must be known in this context", - kind, - ); - err.span_label(span, data.cannot_infer_msg()); - err + generator_kind: GeneratorKindAsDiagArg(kind), + } + .into_diagnostic(&self.tcx.sess.parse_sess.span_diagnostic) + } +} + +pub struct GeneratorKindAsDiagArg(pub hir::GeneratorKind); + +impl IntoDiagnosticArg for GeneratorKindAsDiagArg { + fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> { + let kind = match self.0 { + hir::GeneratorKind::Async(hir::AsyncGeneratorKind::Block) => "async_block", + hir::GeneratorKind::Async(hir::AsyncGeneratorKind::Closure) => "async_closure", + hir::GeneratorKind::Async(hir::AsyncGeneratorKind::Fn) => "async_fn", + hir::GeneratorKind::Gen => "generator", + }; + rustc_errors::DiagnosticArgValue::Str(kind.into()) } } @@ -545,6 +622,7 @@ enum InferSourceKind<'tcx> { generics_def_id: DefId, def_id: DefId, generic_args: &'tcx [GenericArg<'tcx>], + have_turbofish: bool, }, FullyQualifiedMethodCall { receiver: &'tcx Expr<'tcx>, @@ -579,22 +657,22 @@ impl<'tcx> InferSource<'tcx> { } impl<'tcx> InferSourceKind<'tcx> { - fn ty_msg(&self, infcx: &InferCtxt<'_, 'tcx>) -> String { + fn ty_localized_msg(&self, infcx: &InferCtxt<'tcx>) -> (&'static str, String) { match *self { InferSourceKind::LetBinding { ty, .. } | InferSourceKind::ClosureArg { ty, .. } | InferSourceKind::ClosureReturn { ty, .. } => { if ty.is_closure() { - format!(" for the closure `{}`", closure_as_fn_str(infcx, ty)) + ("closure", closure_as_fn_str(infcx, ty)) } else if !ty.is_ty_infer() { - format!(" for `{}`", ty_to_string(infcx, ty)) + ("normal", ty_to_string(infcx, ty)) } else { - String::new() + ("other", String::new()) } } // FIXME: We should be able to add some additional info here. InferSourceKind::GenericArg { .. } - | InferSourceKind::FullyQualifiedMethodCall { .. } => String::new(), + | InferSourceKind::FullyQualifiedMethodCall { .. } => ("other", String::new()), } } } @@ -605,6 +683,7 @@ struct InsertableGenericArgs<'tcx> { substs: SubstsRef<'tcx>, generics_def_id: DefId, def_id: DefId, + have_turbofish: bool, } /// A visitor which searches for the "best" spot to use in the inference error. @@ -615,7 +694,7 @@ struct InsertableGenericArgs<'tcx> { /// While doing so, the currently best spot is stored in `infer_source`. /// For details on how we rank spots, see [Self::source_cost] struct FindInferSourceVisitor<'a, 'tcx> { - infcx: &'a InferCtxt<'a, 'tcx>, + infcx: &'a InferCtxt<'tcx>, typeck_results: &'a TypeckResults<'tcx>, target: GenericArg<'tcx>, @@ -627,7 +706,7 @@ struct FindInferSourceVisitor<'a, 'tcx> { impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { fn new( - infcx: &'a InferCtxt<'a, 'tcx>, + infcx: &'a InferCtxt<'tcx>, typeck_results: &'a TypeckResults<'tcx>, target: GenericArg<'tcx>, ) -> Self { @@ -823,14 +902,21 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { // impl is currently the `DefId` of `Output` in the trait definition // which makes this somewhat difficult and prevents us from just // using `self.path_inferred_subst_iter` here. - hir::ExprKind::Struct(&hir::QPath::Resolved(_self_ty, path), _, _) => { - if let Some(ty) = self.opt_node_type(expr.hir_id) { - if let ty::Adt(_, substs) = ty.kind() { - return Box::new(self.resolved_path_inferred_subst_iter(path, substs)); - } + hir::ExprKind::Struct(&hir::QPath::Resolved(_self_ty, path), _, _) + // FIXME(TaKO8Ki): Ideally we should support this. For that + // we have to map back from the self type to the + // type alias though. That's difficult. + // + // See the `need_type_info/issue-103053.rs` test for + // a example. + if !matches!(path.res, Res::Def(DefKind::TyAlias, _)) => { + if let Some(ty) = self.opt_node_type(expr.hir_id) + && let ty::Adt(_, substs) = ty.kind() + { + return Box::new(self.resolved_path_inferred_subst_iter(path, substs)); } } - hir::ExprKind::MethodCall(segment, _, _) => { + hir::ExprKind::MethodCall(segment, ..) => { if let Some(def_id) = self.typeck_results.type_dependent_def_id(expr.hir_id) { let generics = tcx.generics_of(def_id); let insertable: Option<_> = try { @@ -838,13 +924,14 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { None? } let substs = self.node_substs_opt(expr.hir_id)?; - let span = tcx.hir().span(segment.hir_id?); + let span = tcx.hir().span(segment.hir_id); let insert_span = segment.ident.span.shrink_to_hi().with_hi(span.hi()); InsertableGenericArgs { insert_span, substs, generics_def_id: def_id, def_id, + have_turbofish: false, } }; return Box::new(insertable.into_iter()); @@ -862,6 +949,9 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { substs: SubstsRef<'tcx>, ) -> impl Iterator<Item = InsertableGenericArgs<'tcx>> + 'a { let tcx = self.infcx.tcx; + let have_turbofish = path.segments.iter().any(|segment| { + segment.args.map_or(false, |args| args.args.iter().any(|arg| arg.is_ty_or_const())) + }); // The last segment of a path often has `Res::Err` and the // correct `Res` is the one of the whole path. // @@ -871,7 +961,7 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { let generics_def_id = tcx.res_generics_def_id(path.res)?; let generics = tcx.generics_of(generics_def_id); if generics.has_impl_trait() { - None? + None?; } let insert_span = path.segments.last().unwrap().ident.span.shrink_to_hi().with_hi(path.span.hi()); @@ -880,25 +970,27 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { substs, generics_def_id, def_id: path.res.def_id(), + have_turbofish, } }; path.segments .iter() .filter_map(move |segment| { - let res = segment.res?; + let res = segment.res; let generics_def_id = tcx.res_generics_def_id(res)?; let generics = tcx.generics_of(generics_def_id); if generics.has_impl_trait() { return None; } - let span = tcx.hir().span(segment.hir_id?); + let span = tcx.hir().span(segment.hir_id); let insert_span = segment.ident.span.shrink_to_hi().with_hi(span.hi()); Some(InsertableGenericArgs { insert_span, substs, generics_def_id, def_id: res.def_id(), + have_turbofish, }) }) .chain(last_segment_using_path_data) @@ -925,9 +1017,15 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { if !segment.infer_args || generics.has_impl_trait() { None?; } - let span = tcx.hir().span(segment.hir_id?); + let span = tcx.hir().span(segment.hir_id); let insert_span = segment.ident.span.shrink_to_hi().with_hi(span.hi()); - InsertableGenericArgs { insert_span, substs, generics_def_id: def_id, def_id } + InsertableGenericArgs { + insert_span, + substs, + generics_def_id: def_id, + def_id, + have_turbofish: false, + } }; let parent_def_id = generics.parent.unwrap(); @@ -950,7 +1048,7 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { } // There cannot be inference variables in the self type, // so there's nothing for us to do here. - Res::SelfTy { .. } => {} + Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } => {} _ => warn!( "unexpected path: def={:?} substs={:?} path={:?}", def, substs, path, @@ -1050,7 +1148,13 @@ impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx> { for args in self.expr_inferred_subst_iter(expr) { debug!(?args); - let InsertableGenericArgs { insert_span, substs, generics_def_id, def_id } = args; + let InsertableGenericArgs { + insert_span, + substs, + generics_def_id, + def_id, + have_turbofish, + } = args; let generics = tcx.generics_of(generics_def_id); if let Some(argument_index) = generics .own_substs(substs) @@ -1061,7 +1165,7 @@ impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx> { let generic_args = &generics.own_substs_no_defaults(tcx, substs) [generics.own_counts().lifetimes..]; let span = match expr.kind { - ExprKind::MethodCall(path, _, _) => path.ident.span, + ExprKind::MethodCall(path, ..) => path.ident.span, _ => expr.span, }; @@ -1073,6 +1177,7 @@ impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx> { generics_def_id, def_id, generic_args, + have_turbofish, }, }); } @@ -1110,7 +1215,7 @@ impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx> { }) .any(|generics| generics.has_impl_trait()) }; - if let ExprKind::MethodCall(path, args, span) = expr.kind + if let ExprKind::MethodCall(path, receiver, args, span) = expr.kind && let Some(substs) = self.node_substs_opt(expr.hir_id) && substs.iter().any(|arg| self.generic_arg_contains_target(arg)) && let Some(def_id) = self.typeck_results.type_dependent_def_id(expr.hir_id) @@ -1118,12 +1223,12 @@ impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx> { && !has_impl_trait(def_id) { let successor = - args.get(1).map_or_else(|| (")", span.hi()), |arg| (", ", arg.span.lo())); + args.get(0).map_or_else(|| (")", span.hi()), |arg| (", ", arg.span.lo())); let substs = self.infcx.resolve_vars_if_possible(substs); self.update_infer_source(InferSource { span: path.ident.span, kind: InferSourceKind::FullyQualifiedMethodCall { - receiver: args.first().unwrap(), + receiver, successor, substs, def_id, |