diff options
| -rw-r--r-- | src/librustc_typeck/astconv.rs | 73 | ||||
| -rw-r--r-- | src/test/ui/const-generics/const-arg-type-arg-misordered.stderr | 1 | ||||
| -rw-r--r-- | src/test/ui/suggestions/suggest-move-types.stderr | 2 |
3 files changed, 70 insertions, 6 deletions
diff --git a/src/librustc_typeck/astconv.rs b/src/librustc_typeck/astconv.rs index 33d57e25711..1b08bf2fc77 100644 --- a/src/librustc_typeck/astconv.rs +++ b/src/librustc_typeck/astconv.rs @@ -8,8 +8,7 @@ use crate::collect::PlaceholderHirTyCollector; use crate::middle::resolve_lifetime as rl; use crate::require_c_abi_if_c_variadic; -use rustc_ast::ast::ParamKindOrd; -use rustc_ast::util::lev_distance::find_best_match_for_name; +use rustc_ast::{ast::ParamKindOrd, util::lev_distance::find_best_match_for_name}; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_errors::ErrorReported; use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticId, FatalError}; @@ -27,7 +26,7 @@ use rustc_middle::ty::{GenericParamDef, GenericParamDefKind}; use rustc_session::lint::builtin::{AMBIGUOUS_ASSOCIATED_ITEMS, LATE_BOUND_LIFETIME_ARGUMENTS}; use rustc_session::parse::feature_err; use rustc_session::Session; -use rustc_span::symbol::{sym, Ident, Symbol}; +use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::{MultiSpan, Span, DUMMY_SP}; use rustc_target::spec::abi; use rustc_trait_selection::traits; @@ -475,7 +474,12 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { /// Report an error that a generic argument did not match the generic parameter that was /// expected. - fn generic_arg_mismatch_err(sess: &Session, arg: &GenericArg<'_>, kind: &'static str) { + fn generic_arg_mismatch_err( + sess: &Session, + arg: &GenericArg<'_>, + kind: &'static str, + help: Option<&str>, + ) { let mut err = struct_span_err!( sess, arg.span(), @@ -503,6 +507,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { let (first, last) = if kind_ord < arg_ord { (kind, arg.descr()) } else { (arg.descr(), kind) }; err.note(&format!("{} arguments must be provided before {} arguments", first, last)); + + if let Some(help) = help { + err.help(help); + } err.emit(); } @@ -648,7 +656,60 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { if arg_count.correct.is_ok() && arg_count.explicit_late_bound == ExplicitLateBound::No { - Self::generic_arg_mismatch_err(tcx.sess, arg, kind.descr()); + // We're going to iterate over the parameters to sort them out, and + // show that order to the user as a possible order for the parameters + let mut param_types_present = defs + .params + .clone() + .into_iter() + .map(|param| { + ( + match param.kind { + GenericParamDefKind::Lifetime => { + ParamKindOrd::Lifetime + } + GenericParamDefKind::Type { .. } => { + ParamKindOrd::Type + } + GenericParamDefKind::Const => { + ParamKindOrd::Const + } + }, + param, + ) + }) + .collect::<Vec<(ParamKindOrd, GenericParamDef)>>(); + param_types_present.sort_by_key(|(ord, _)| *ord); + let (mut param_types_present, ordered_params): ( + Vec<ParamKindOrd>, + Vec<GenericParamDef>, + ) = param_types_present.into_iter().unzip(); + param_types_present.dedup(); + + Self::generic_arg_mismatch_err( + tcx.sess, + arg, + kind.descr(), + Some(&format!( + "reorder the arguments: {}: `<{}>`", + param_types_present + .into_iter() + .map(|ord| format!("{}s", ord.to_string())) + .collect::<Vec<String>>() + .join(", then "), + ordered_params + .into_iter() + .filter_map(|param| { + if param.name == kw::SelfUpper { + None + } else { + Some(param.name.to_string()) + } + }) + .collect::<Vec<String>>() + .join(", ") + )), + ); } // We've reported the error, but we want to make sure that this @@ -680,7 +741,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { assert_eq!(kind, "lifetime"); let provided = force_infer_lt.expect("lifetimes ought to have been inferred"); - Self::generic_arg_mismatch_err(tcx.sess, provided, kind); + Self::generic_arg_mismatch_err(tcx.sess, provided, kind, None); } break; diff --git a/src/test/ui/const-generics/const-arg-type-arg-misordered.stderr b/src/test/ui/const-generics/const-arg-type-arg-misordered.stderr index ad38b632b75..4a6241de1b4 100644 --- a/src/test/ui/const-generics/const-arg-type-arg-misordered.stderr +++ b/src/test/ui/const-generics/const-arg-type-arg-misordered.stderr @@ -14,6 +14,7 @@ LL | fn foo<const N: usize>() -> Array<N, ()> { | ^ | = note: type arguments must be provided before constant arguments + = help: reorder the arguments: types, then consts: `<T, N>` error: aborting due to previous error; 1 warning emitted diff --git a/src/test/ui/suggestions/suggest-move-types.stderr b/src/test/ui/suggestions/suggest-move-types.stderr index 96f1656bae4..3c2226574ee 100644 --- a/src/test/ui/suggestions/suggest-move-types.stderr +++ b/src/test/ui/suggestions/suggest-move-types.stderr @@ -125,6 +125,7 @@ LL | struct Cl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, 'a, A=(), B=(), C=() | ^^ | = note: lifetime arguments must be provided before type arguments + = help: reorder the arguments: lifetimes, then types: `<'a, 'b, 'c, T, U, V>` error[E0747]: lifetime provided when a type was expected --> $DIR/suggest-move-types.rs:82:56 @@ -133,6 +134,7 @@ LL | struct Dl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, 'a, A=(), B=(), U, ' | ^^ | = note: lifetime arguments must be provided before type arguments + = help: reorder the arguments: lifetimes, then types: `<'a, 'b, 'c, T, U, V>` error: aborting due to 12 previous errors |