diff options
Diffstat (limited to 'compiler/rustc_hir_analysis/src')
| -rw-r--r-- | compiler/rustc_hir_analysis/src/astconv/errors.rs | 107 | ||||
| -rw-r--r-- | compiler/rustc_hir_analysis/src/astconv/generics.rs | 12 | ||||
| -rw-r--r-- | compiler/rustc_hir_analysis/src/astconv/mod.rs | 13 | ||||
| -rw-r--r-- | compiler/rustc_hir_analysis/src/errors.rs | 12 |
4 files changed, 93 insertions, 51 deletions
diff --git a/compiler/rustc_hir_analysis/src/astconv/errors.rs b/compiler/rustc_hir_analysis/src/astconv/errors.rs index c49e4d9d581..156334fe785 100644 --- a/compiler/rustc_hir_analysis/src/astconv/errors.rs +++ b/compiler/rustc_hir_analysis/src/astconv/errors.rs @@ -1,10 +1,14 @@ use crate::astconv::AstConv; -use crate::errors::{ManualImplementation, MissingTypeParams}; +use crate::errors::{ + AssocTypeBindingNotAllowed, ManualImplementation, MissingTypeParams, + ParenthesizedFnTraitExpansion, +}; use rustc_data_structures::fx::FxHashMap; use rustc_errors::{pluralize, struct_span_err, Applicability, Diagnostic, ErrorGuaranteed}; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_infer::traits::FulfillmentError; +use rustc_middle::ty::TyCtxt; use rustc_middle::ty::{self, Ty}; use rustc_session::parse::feature_err; use rustc_span::edit_distance::find_best_match_for_name; @@ -78,43 +82,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { // Do not suggest the other syntax if we are in trait impl: // the desugaring would contain an associated type constraint. if !is_impl { - let args = trait_segment - .args - .as_ref() - .and_then(|args| args.args.get(0)) - .and_then(|arg| match arg { - hir::GenericArg::Type(ty) => match ty.kind { - hir::TyKind::Tup(t) => t - .iter() - .map(|e| sess.source_map().span_to_snippet(e.span)) - .collect::<Result<Vec<_>, _>>() - .map(|a| a.join(", ")), - _ => sess.source_map().span_to_snippet(ty.span), - } - .map(|s| format!("({})", s)) - .ok(), - _ => None, - }) - .unwrap_or_else(|| "()".to_string()); - let ret = trait_segment - .args() - .bindings - .iter() - .find_map(|b| match (b.ident.name == sym::Output, &b.kind) { - (true, hir::TypeBindingKind::Equality { term }) => { - let span = match term { - hir::Term::Ty(ty) => ty.span, - hir::Term::Const(c) => self.tcx().hir().span(c.hir_id), - }; - sess.source_map().span_to_snippet(span).ok() - } - _ => None, - }) - .unwrap_or_else(|| "()".to_string()); err.span_suggestion( span, "use parenthetical notation instead", - format!("{}{} -> {}", trait_segment.ident, args, ret), + fn_trait_to_string(self.tcx(), trait_segment, true), Applicability::MaybeIncorrect, ); } @@ -629,3 +600,69 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { err.emit(); } } + +/// Emits an error regarding forbidden type binding associations +pub fn prohibit_assoc_ty_binding( + tcx: TyCtxt<'_>, + span: Span, + segment: Option<(&hir::PathSegment<'_>, Span)>, +) { + tcx.sess.emit_err(AssocTypeBindingNotAllowed { span, fn_trait_expansion: if let Some((segment, span)) = segment && segment.args().parenthesized { + Some(ParenthesizedFnTraitExpansion { span, expanded_type: fn_trait_to_string(tcx, segment, false) }) + } else { + None + }}); +} + +pub(crate) fn fn_trait_to_string( + tcx: TyCtxt<'_>, + trait_segment: &hir::PathSegment<'_>, + parenthesized: bool, +) -> String { + let args = trait_segment + .args + .as_ref() + .and_then(|args| args.args.get(0)) + .and_then(|arg| match arg { + hir::GenericArg::Type(ty) => match ty.kind { + hir::TyKind::Tup(t) => t + .iter() + .map(|e| tcx.sess.source_map().span_to_snippet(e.span)) + .collect::<Result<Vec<_>, _>>() + .map(|a| a.join(", ")), + _ => tcx.sess.source_map().span_to_snippet(ty.span), + } + .map(|s| { + // `s.empty()` checks to see if the type is the unit tuple, if so we don't want a comma + if parenthesized || s.is_empty() { format!("({})", s) } else { format!("({},)", s) } + }) + .ok(), + _ => None, + }) + .unwrap_or_else(|| "()".to_string()); + + let ret = trait_segment + .args() + .bindings + .iter() + .find_map(|b| match (b.ident.name == sym::Output, &b.kind) { + (true, hir::TypeBindingKind::Equality { term }) => { + let span = match term { + hir::Term::Ty(ty) => ty.span, + hir::Term::Const(c) => tcx.hir().span(c.hir_id), + }; + + (span != tcx.hir().span(trait_segment.hir_id)) + .then_some(tcx.sess.source_map().span_to_snippet(span).ok()) + .flatten() + } + _ => None, + }) + .unwrap_or_else(|| "()".to_string()); + + if parenthesized { + format!("{}{} -> {}", trait_segment.ident, args, ret) + } else { + format!("{}<{}, Output={}>", trait_segment.ident, args, ret) + } +} diff --git a/compiler/rustc_hir_analysis/src/astconv/generics.rs b/compiler/rustc_hir_analysis/src/astconv/generics.rs index 7f6518ffd71..2f4963f6bc3 100644 --- a/compiler/rustc_hir_analysis/src/astconv/generics.rs +++ b/compiler/rustc_hir_analysis/src/astconv/generics.rs @@ -1,9 +1,8 @@ use super::IsMethodCall; use crate::astconv::{ - CreateSubstsForGenericArgsCtxt, ExplicitLateBound, GenericArgCountMismatch, - GenericArgCountResult, GenericArgPosition, + errors::prohibit_assoc_ty_binding, CreateSubstsForGenericArgsCtxt, ExplicitLateBound, + GenericArgCountMismatch, GenericArgCountResult, GenericArgPosition, }; -use crate::errors::AssocTypeBindingNotAllowed; use crate::structured_errors::{GenericArgsInfo, StructuredDiagnostic, WrongNumberOfGenericArgs}; use rustc_ast::ast::ParamKindOrd; use rustc_errors::{struct_span_err, Applicability, Diagnostic, ErrorGuaranteed, MultiSpan}; @@ -433,7 +432,7 @@ pub(crate) fn check_generic_arg_count( (gen_pos != GenericArgPosition::Type || infer_args) && !gen_args.has_lifetime_params(); if gen_pos != GenericArgPosition::Type && let Some(b) = gen_args.bindings.first() { - prohibit_assoc_ty_binding(tcx, b.span); + prohibit_assoc_ty_binding(tcx, b.span, None); } let explicit_late_bound = @@ -589,11 +588,6 @@ pub(crate) fn check_generic_arg_count( } } -/// Emits an error regarding forbidden type binding associations -pub fn prohibit_assoc_ty_binding(tcx: TyCtxt<'_>, span: Span) { - tcx.sess.emit_err(AssocTypeBindingNotAllowed { span }); -} - /// Prohibits explicit lifetime arguments if late-bound lifetime parameters /// are present. This is used both for datatypes and function calls. pub(crate) fn prohibit_explicit_late_bound_lifetimes( diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs index 899029d98e0..5db404608b3 100644 --- a/compiler/rustc_hir_analysis/src/astconv/mod.rs +++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs @@ -5,9 +5,8 @@ mod errors; pub mod generics; -use crate::astconv::generics::{ - check_generic_arg_count, create_substs_for_generic_args, prohibit_assoc_ty_binding, -}; +use crate::astconv::errors::prohibit_assoc_ty_binding; +use crate::astconv::generics::{check_generic_arg_count, create_substs_for_generic_args}; use crate::bounds::Bounds; use crate::collect::HirPlaceholderCollector; use crate::errors::{ @@ -295,7 +294,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { ty::BoundConstness::NotConst, ); if let Some(b) = item_segment.args().bindings.first() { - prohibit_assoc_ty_binding(self.tcx(), b.span); + prohibit_assoc_ty_binding(self.tcx(), b.span, Some((item_segment, span))); } substs @@ -631,7 +630,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { ); if let Some(b) = item_segment.args().bindings.first() { - prohibit_assoc_ty_binding(self.tcx(), b.span); + prohibit_assoc_ty_binding(self.tcx(), b.span, Some((item_segment, span))); } args @@ -825,7 +824,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { constness, ); if let Some(b) = trait_segment.args().bindings.first() { - prohibit_assoc_ty_binding(self.tcx(), b.span); + prohibit_assoc_ty_binding(self.tcx(), b.span, Some((trait_segment, span))); } self.tcx().mk_trait_ref(trait_def_id, substs) } @@ -2596,7 +2595,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { for segment in segments { // Only emit the first error to avoid overloading the user with error messages. if let Some(b) = segment.args().bindings.first() { - prohibit_assoc_ty_binding(self.tcx(), b.span); + prohibit_assoc_ty_binding(self.tcx(), b.span, None); return true; } } diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs index dd40706f1d3..8a697b4c514 100644 --- a/compiler/rustc_hir_analysis/src/errors.rs +++ b/compiler/rustc_hir_analysis/src/errors.rs @@ -129,6 +129,18 @@ pub struct AssocTypeBindingNotAllowed { #[primary_span] #[label] pub span: Span, + + #[subdiagnostic] + pub fn_trait_expansion: Option<ParenthesizedFnTraitExpansion>, +} + +#[derive(Subdiagnostic)] +#[help(hir_analysis_parenthesized_fn_trait_expansion)] +pub struct ParenthesizedFnTraitExpansion { + #[primary_span] + pub span: Span, + + pub expanded_type: String, } #[derive(Diagnostic)] |