diff options
Diffstat (limited to 'compiler/rustc_hir_analysis/src/check/wfcheck.rs')
| -rw-r--r-- | compiler/rustc_hir_analysis/src/check/wfcheck.rs | 84 |
1 files changed, 65 insertions, 19 deletions
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs index fb9bcc113c6..2ed31d837a8 100644 --- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs +++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs @@ -1651,6 +1651,14 @@ fn check_fn_or_method<'tcx>( } } +/// The `arbitrary_self_types_pointers` feature implies `arbitrary_self_types`. +#[derive(Clone, Copy)] +enum ArbitrarySelfTypesLevel { + None, // neither arbitrary_self_types nor arbitrary_self_types_pointers + ArbitrarySelfTypes, // just arbitrary_self_types + ArbitrarySelfTypesPointers, // both arbitrary_self_types and arbitrary_self_types_pointers +} + #[instrument(level = "debug", skip(wfcx))] fn check_method_receiver<'tcx>( wfcx: &WfCheckingCtxt<'_, 'tcx>, @@ -1683,14 +1691,28 @@ fn check_method_receiver<'tcx>( return Ok(()); } - if tcx.features().arbitrary_self_types { - if !receiver_is_valid(wfcx, span, receiver_ty, self_ty, true) { - // Report error; `arbitrary_self_types` was enabled. - return Err(tcx.dcx().emit_err(errors::InvalidReceiverTy { span, receiver_ty })); - } + let arbitrary_self_types_level = if tcx.features().arbitrary_self_types_pointers { + ArbitrarySelfTypesLevel::ArbitrarySelfTypesPointers + } else if tcx.features().arbitrary_self_types { + ArbitrarySelfTypesLevel::ArbitrarySelfTypes } else { - if !receiver_is_valid(wfcx, span, receiver_ty, self_ty, false) { - return Err(if receiver_is_valid(wfcx, span, receiver_ty, self_ty, true) { + ArbitrarySelfTypesLevel::None + }; + + if !receiver_is_valid(wfcx, span, receiver_ty, self_ty, arbitrary_self_types_level) { + return Err(match arbitrary_self_types_level { + // Wherever possible, emit a message advising folks that the features + // `arbitrary_self_types` or `arbitrary_self_types_pointers` might + // have helped. + ArbitrarySelfTypesLevel::None + if receiver_is_valid( + wfcx, + span, + receiver_ty, + self_ty, + ArbitrarySelfTypesLevel::ArbitrarySelfTypes, + ) => + { // Report error; would have worked with `arbitrary_self_types`. feature_err( &tcx.sess, @@ -1698,25 +1720,49 @@ fn check_method_receiver<'tcx>( span, format!( "`{receiver_ty}` cannot be used as the type of `self` without \ - the `arbitrary_self_types` feature", + the `arbitrary_self_types` feature", ), ) .with_help(fluent::hir_analysis_invalid_receiver_ty_help) .emit() - } else { - // Report error; would not have worked with `arbitrary_self_types`. + } + ArbitrarySelfTypesLevel::ArbitrarySelfTypes | ArbitrarySelfTypesLevel::None + if receiver_is_valid( + wfcx, + span, + receiver_ty, + self_ty, + ArbitrarySelfTypesLevel::ArbitrarySelfTypesPointers, + ) => + { + // Report error; would have worked with `arbitrary_self_types_pointers`. + feature_err( + &tcx.sess, + sym::arbitrary_self_types_pointers, + span, + format!( + "`{receiver_ty}` cannot be used as the type of `self` without \ + the `arbitrary_self_types_pointers` feature", + ), + ) + .with_help(fluent::hir_analysis_invalid_receiver_ty_help) + .emit() + } + _ => + // Report error; would not have worked with `arbitrary_self_types[_pointers]`. + { tcx.dcx().emit_err(errors::InvalidReceiverTy { span, receiver_ty }) - }); - } + } + }); } Ok(()) } /// Returns whether `receiver_ty` would be considered a valid receiver type for `self_ty`. If /// `arbitrary_self_types` is enabled, `receiver_ty` must transitively deref to `self_ty`, possibly -/// through a `*const/mut T` raw pointer. If the feature is not enabled, the requirements are more -/// strict: `receiver_ty` must implement `Receiver` and directly implement -/// `Deref<Target = self_ty>`. +/// through a `*const/mut T` raw pointer if `arbitrary_self_types_pointers` is also enabled. +/// If neither feature is enabled, the requirements are more strict: `receiver_ty` must implement +/// `Receiver` and directly implement `Deref<Target = self_ty>`. /// /// N.B., there are cases this function returns `true` but causes an error to be emitted, /// particularly when `receiver_ty` derefs to a type that is the same as `self_ty` but has the @@ -1726,7 +1772,7 @@ fn receiver_is_valid<'tcx>( span: Span, receiver_ty: Ty<'tcx>, self_ty: Ty<'tcx>, - arbitrary_self_types_enabled: bool, + arbitrary_self_types_enabled: ArbitrarySelfTypesLevel, ) -> bool { let infcx = wfcx.infcx; let tcx = wfcx.tcx(); @@ -1744,8 +1790,8 @@ fn receiver_is_valid<'tcx>( let mut autoderef = Autoderef::new(infcx, wfcx.param_env, wfcx.body_def_id, span, receiver_ty); - // The `arbitrary_self_types` feature allows raw pointer receivers like `self: *const Self`. - if arbitrary_self_types_enabled { + // The `arbitrary_self_types_pointers` feature allows raw pointer receivers like `self: *const Self`. + if matches!(arbitrary_self_types_enabled, ArbitrarySelfTypesLevel::ArbitrarySelfTypesPointers) { autoderef = autoderef.include_raw_pointers(); } @@ -1771,7 +1817,7 @@ fn receiver_is_valid<'tcx>( // Without `feature(arbitrary_self_types)`, we require that each step in the // deref chain implement `receiver`. - if !arbitrary_self_types_enabled { + if matches!(arbitrary_self_types_enabled, ArbitrarySelfTypesLevel::None) { if !receiver_is_implemented( wfcx, receiver_trait_def_id, |