diff options
7 files changed, 230 insertions, 12 deletions
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs index 63226504d37..19b4d0c2bdf 100644 --- a/compiler/rustc_errors/src/lib.rs +++ b/compiler/rustc_errors/src/lib.rs @@ -507,6 +507,7 @@ pub enum StashKey { CallAssocMethod, TraitMissingMethod, OpaqueHiddenTypeMismatch, + MaybeForgetReturn, } fn default_track_diagnostic(d: &mut Diagnostic, f: &mut dyn FnMut(&mut Diagnostic)) { diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs index 5dae74a1f9b..98cdeb64532 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs @@ -564,7 +564,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { if !errors.is_empty() { self.adjust_fulfillment_errors_for_expr_obligation(&mut errors); + let errors_causecode = errors + .iter() + .map(|e| (e.obligation.cause.span, e.root_obligation.cause.code().clone())) + .collect::<Vec<_>>(); self.err_ctxt().report_fulfillment_errors(errors); + self.collect_unused_stmts_for_coerce_return_ty(errors_causecode); } } diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs index c762e684480..5979a6e213e 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs @@ -11,7 +11,7 @@ use crate::{ use rustc_ast as ast; use rustc_data_structures::fx::FxIndexSet; use rustc_errors::{ - pluralize, Applicability, Diagnostic, DiagnosticId, ErrorGuaranteed, MultiSpan, + pluralize, Applicability, Diagnostic, DiagnosticId, ErrorGuaranteed, MultiSpan, StashKey, }; use rustc_hir as hir; use rustc_hir::def::{CtorOf, DefKind, Res}; @@ -27,6 +27,7 @@ use rustc_infer::infer::error_reporting::{FailureCode, ObligationCauseExt}; use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use rustc_infer::infer::TypeTrace; use rustc_infer::infer::{DefineOpaqueTypes, InferOk}; +use rustc_middle::traits::ObligationCauseCode::ExprBindingObligation; use rustc_middle::ty::adjustment::AllowTwoPhase; use rustc_middle::ty::visit::TypeVisitableExt; use rustc_middle::ty::{self, IsSuggestable, Ty, TyCtxt}; @@ -1375,7 +1376,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } _ => bug!("unexpected type: {:?}", ty.normalized), }, - Res::Def(DefKind::Struct | DefKind::Union | DefKind::TyAlias | DefKind::AssocTy, _) + Res::Def( + DefKind::Struct | DefKind::Union | DefKind::TyAlias { .. } | DefKind::AssocTy, + _, + ) | Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } => match ty.normalized.ty_adt_def() { Some(adt) if !adt.is_enum() => { @@ -1845,6 +1849,55 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } } + pub(super) fn collect_unused_stmts_for_coerce_return_ty( + &self, + errors_causecode: Vec<(Span, ObligationCauseCode<'tcx>)>, + ) { + for (span, code) in errors_causecode { + let Some(mut diag) = + self.tcx.sess.diagnostic().steal_diagnostic(span, StashKey::MaybeForgetReturn) + else { + continue; + }; + + if let Some(fn_sig) = self.body_fn_sig() + && let ExprBindingObligation(_, _, hir_id, ..) = code + && !fn_sig.output().is_unit() + { + let mut block_num = 0; + let mut found_semi = false; + for (_, node) in self.tcx.hir().parent_iter(hir_id) { + match node { + hir::Node::Stmt(stmt) => if let hir::StmtKind::Semi(ref expr) = stmt.kind { + let expr_ty = self.typeck_results.borrow().expr_ty(expr); + let return_ty = fn_sig.output(); + if !matches!(expr.kind, hir::ExprKind::Ret(..)) && + self.can_coerce(expr_ty, return_ty) { + found_semi = true; + } + }, + hir::Node::Block(_block) => if found_semi { + block_num += 1; + } + hir::Node::Item(item) => if let hir::ItemKind::Fn(..) = item.kind { + break; + } + _ => {} + } + } + if block_num > 1 && found_semi { + diag.span_suggestion_verbose( + span.shrink_to_lo(), + "you might have meant to return this to infer its type parameters", + "return ", + Applicability::MaybeIncorrect, + ); + } + } + diag.emit(); + } + } + /// Given a vector of fulfillment errors, try to adjust the spans of the /// errors to more accurately point at the cause of the failure. /// diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs index 8adfb27a3f4..96d9873646d 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs @@ -17,7 +17,7 @@ use crate::traits::{ use rustc_data_structures::fx::{FxHashMap, FxIndexMap}; use rustc_errors::{ pluralize, struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, - MultiSpan, Style, + MultiSpan, StashKey, Style, }; use rustc_hir as hir; use rustc_hir::def::{DefKind, Namespace, Res}; @@ -2049,14 +2049,14 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { // begin with in those cases. if self.tcx.lang_items().sized_trait() == Some(trait_ref.def_id()) { if let None = self.tainted_by_errors() { - self.emit_inference_failure_err( + let err = self.emit_inference_failure_err( obligation.cause.body_id, span, trait_ref.self_ty().skip_binder().into(), ErrorCode::E0282, false, - ) - .emit(); + ); + err.stash(span, StashKey::MaybeForgetReturn); } return; } diff --git a/tests/ui/inference/issue-86094-suggest-add-return-to-coerce-ret-ty.rs b/tests/ui/inference/issue-86094-suggest-add-return-to-coerce-ret-ty.rs new file mode 100644 index 00000000000..4544c898ab8 --- /dev/null +++ b/tests/ui/inference/issue-86094-suggest-add-return-to-coerce-ret-ty.rs @@ -0,0 +1,61 @@ +struct MyError; + +fn foo(x: bool) -> Result<(), MyError> { + if x { + Err(MyError); + //~^ ERROR type annotations needed + } + + Ok(()) +} + +fn bar(x: bool) -> Result<(), MyError> { + if x { + Ok(()); + //~^ ERROR type annotations needed + } + + Ok(()) +} + +fn baz(x: bool) -> Result<(), MyError> { + //~^ ERROR mismatched types + if x { + 1; + } + + Err(MyError); +} + +fn error() -> Result<(), MyError> { + Err(MyError) +} + +fn bak(x: bool) -> Result<(), MyError> { + if x { + //~^ ERROR mismatched types + error(); + } else { + //~^ ERROR mismatched types + error(); + } +} + +fn bad(x: bool) -> Result<(), MyError> { + Err(MyError); //~ ERROR type annotations needed + Ok(()) +} + +fn with_closure<F, A, B>(_: F) -> i32 +where + F: FnOnce(A, B), +{ + 0 +} + +fn a() -> i32 { + with_closure(|x: u32, y| {}); //~ ERROR type annotations needed + 0 +} + +fn main() {} diff --git a/tests/ui/inference/issue-86094-suggest-add-return-to-coerce-ret-ty.stderr b/tests/ui/inference/issue-86094-suggest-add-return-to-coerce-ret-ty.stderr new file mode 100644 index 00000000000..1fea73529a8 --- /dev/null +++ b/tests/ui/inference/issue-86094-suggest-add-return-to-coerce-ret-ty.stderr @@ -0,0 +1,98 @@ +error[E0282]: type annotations needed + --> $DIR/issue-86094-suggest-add-return-to-coerce-ret-ty.rs:5:9 + | +LL | Err(MyError); + | ^^^ cannot infer type of the type parameter `T` declared on the enum `Result` + | +help: consider specifying the generic arguments + | +LL | Err::<T, MyError>(MyError); + | ++++++++++++++ +help: you might have meant to return this to infer its type parameters + | +LL | return Err(MyError); + | ++++++ + +error[E0282]: type annotations needed + --> $DIR/issue-86094-suggest-add-return-to-coerce-ret-ty.rs:14:9 + | +LL | Ok(()); + | ^^ cannot infer type of the type parameter `E` declared on the enum `Result` + | +help: consider specifying the generic arguments + | +LL | Ok::<(), E>(()); + | +++++++++ +help: you might have meant to return this to infer its type parameters + | +LL | return Ok(()); + | ++++++ + +error[E0308]: mismatched types + --> $DIR/issue-86094-suggest-add-return-to-coerce-ret-ty.rs:21:20 + | +LL | fn baz(x: bool) -> Result<(), MyError> { + | --- ^^^^^^^^^^^^^^^^^^^ expected `Result<(), MyError>`, found `()` + | | + | implicitly returns `()` as its body has no tail or `return` expression +... +LL | Err(MyError); + | - help: remove this semicolon to return this value + | + = note: expected enum `Result<(), MyError>` + found unit type `()` + +error[E0308]: mismatched types + --> $DIR/issue-86094-suggest-add-return-to-coerce-ret-ty.rs:35:10 + | +LL | if x { + | __________^ +LL | | +LL | | error(); + | | - help: remove this semicolon to return this value +LL | | } else { + | |_____^ expected `Result<(), MyError>`, found `()` + | + = note: expected enum `Result<(), MyError>` + found unit type `()` + +error[E0308]: mismatched types + --> $DIR/issue-86094-suggest-add-return-to-coerce-ret-ty.rs:38:12 + | +LL | } else { + | ____________^ +LL | | +LL | | error(); + | | - help: remove this semicolon to return this value +LL | | } + | |_____^ expected `Result<(), MyError>`, found `()` + | + = note: expected enum `Result<(), MyError>` + found unit type `()` + +error[E0282]: type annotations needed + --> $DIR/issue-86094-suggest-add-return-to-coerce-ret-ty.rs:45:5 + | +LL | Err(MyError); + | ^^^ cannot infer type of the type parameter `T` declared on the enum `Result` + | +help: consider specifying the generic arguments + | +LL | Err::<T, MyError>(MyError); + | ++++++++++++++ + +error[E0282]: type annotations needed + --> $DIR/issue-86094-suggest-add-return-to-coerce-ret-ty.rs:57:27 + | +LL | with_closure(|x: u32, y| {}); + | ^ + | +help: consider giving this closure parameter an explicit type + | +LL | with_closure(|x: u32, y: /* Type */| {}); + | ++++++++++++ + +error: aborting due to 7 previous errors + +Some errors have detailed explanations: E0282, E0308. +For more information about an error, try `rustc --explain E0282`. diff --git a/tests/ui/traits/new-solver/specialization-unconstrained.stderr b/tests/ui/traits/new-solver/specialization-unconstrained.stderr index 9915da1a27a..ed4dafa1484 100644 --- a/tests/ui/traits/new-solver/specialization-unconstrained.stderr +++ b/tests/ui/traits/new-solver/specialization-unconstrained.stderr @@ -8,12 +8,6 @@ LL | #![feature(specialization)] = help: consider using `min_specialization` instead, which is more stable and complete = note: `#[warn(incomplete_features)]` on by default -error[E0282]: type annotations needed - --> $DIR/specialization-unconstrained.rs:14:22 - | -LL | default type Id = T; - | ^ cannot infer type for associated type `<T as Default>::Id` - error[E0284]: type annotations needed: cannot satisfy `<u32 as Default>::Id == ()` --> $DIR/specialization-unconstrained.rs:20:5 | @@ -26,6 +20,12 @@ note: required by a bound in `test` LL | fn test<T: Default<Id = U>, U>() {} | ^^^^^^ required by this bound in `test` +error[E0282]: type annotations needed + --> $DIR/specialization-unconstrained.rs:14:22 + | +LL | default type Id = T; + | ^ cannot infer type for associated type `<T as Default>::Id` + error: aborting due to 2 previous errors; 1 warning emitted Some errors have detailed explanations: E0282, E0284. |