diff --git a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs index 7718644b9a9a8..512288a0f7d85 100644 --- a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs +++ b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs @@ -621,13 +621,7 @@ impl<'tcx> LivenessContext<'_, '_, '_, 'tcx> { &ocx, op, span, ) { Ok(_) => ocx.select_all_or_error(), - Err(e) => { - if e.is_empty() { - ocx.select_all_or_error() - } else { - e - } - } + Err(e) => e, }; // Could have no errors if a type lowering error, say, caused the query diff --git a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs index f04a5feba3011..38cfdcdc22d33 100644 --- a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs +++ b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs @@ -196,11 +196,31 @@ where debug!("dropck_outlives: ty from dtorck_types = {:?}", ty); ty } else { - ocx.deeply_normalize(&cause, param_env, ty)?; + // Flush errors b/c `deeply_normalize` doesn't expect pending + // obligations, and we may have pending obligations from the + // branch above (from other types). + let errors = ocx.select_all_or_error(); + if !errors.is_empty() { + return Err(errors); + } - let errors = ocx.select_where_possible(); - debug!("normalize errors: {ty} ~> {errors:#?}"); - return Err(errors); + // When query normalization fails, we don't get back an interesting + // reason that we could use to report an error in borrowck. In order to turn + // this into a reportable error, we deeply normalize again. We don't expect + // this to succeed, so delay a bug if it does. + match ocx.deeply_normalize(&cause, param_env, ty) { + Ok(_) => { + tcx.dcx().span_delayed_bug( + span, + format!( + "query normalize succeeded of {ty}, \ + but deep normalize failed", + ), + ); + ty + } + Err(errors) => return Err(errors), + } }; match ty.kind() { diff --git a/tests/ui/drop/dropck-normalize-errors.rs b/tests/ui/drop/dropck-normalize-errors.rs new file mode 100644 index 0000000000000..793122bd33d4b --- /dev/null +++ b/tests/ui/drop/dropck-normalize-errors.rs @@ -0,0 +1,31 @@ +// Test that we don't ICE when computing the drop types for + +trait Decode<'a> { + type Decoder; +} + +trait NonImplementedTrait { + type Assoc; +} +struct NonImplementedStruct; + +pub struct ADecoder<'a> { + b: >::Decoder, +} +fn make_a_decoder<'a>() -> ADecoder<'a> { + //~^ ERROR the trait bound + //~| ERROR the trait bound + panic!() +} + +struct B; +impl<'a> Decode<'a> for B { + type Decoder = BDecoder; + //~^ ERROR the trait bound +} +pub struct BDecoder { + non_implemented: ::Assoc, + //~^ ERROR the trait bound +} + +fn main() {} diff --git a/tests/ui/drop/dropck-normalize-errors.stderr b/tests/ui/drop/dropck-normalize-errors.stderr new file mode 100644 index 0000000000000..2bb5909c6b226 --- /dev/null +++ b/tests/ui/drop/dropck-normalize-errors.stderr @@ -0,0 +1,76 @@ +error[E0277]: the trait bound `NonImplementedStruct: NonImplementedTrait` is not satisfied in `ADecoder<'a>` + --> $DIR/dropck-normalize-errors.rs:15:28 + | +LL | fn make_a_decoder<'a>() -> ADecoder<'a> { + | ^^^^^^^^^^^^ within `ADecoder<'a>`, the trait `NonImplementedTrait` is not implemented for `NonImplementedStruct` + | +help: this trait has no implementations, consider adding one + --> $DIR/dropck-normalize-errors.rs:7:1 + | +LL | trait NonImplementedTrait { + | ^^^^^^^^^^^^^^^^^^^^^^^^^ +note: required because it appears within the type `BDecoder` + --> $DIR/dropck-normalize-errors.rs:26:12 + | +LL | pub struct BDecoder { + | ^^^^^^^^ +note: required because it appears within the type `ADecoder<'a>` + --> $DIR/dropck-normalize-errors.rs:12:12 + | +LL | pub struct ADecoder<'a> { + | ^^^^^^^^ + = note: the return type of a function must have a statically known size + +error[E0277]: the trait bound `NonImplementedStruct: NonImplementedTrait` is not satisfied in `BDecoder` + --> $DIR/dropck-normalize-errors.rs:23:20 + | +LL | type Decoder = BDecoder; + | ^^^^^^^^ within `BDecoder`, the trait `NonImplementedTrait` is not implemented for `NonImplementedStruct` + | +help: this trait has no implementations, consider adding one + --> $DIR/dropck-normalize-errors.rs:7:1 + | +LL | trait NonImplementedTrait { + | ^^^^^^^^^^^^^^^^^^^^^^^^^ +note: required because it appears within the type `BDecoder` + --> $DIR/dropck-normalize-errors.rs:26:12 + | +LL | pub struct BDecoder { + | ^^^^^^^^ +note: required by a bound in `Decode::Decoder` + --> $DIR/dropck-normalize-errors.rs:4:5 + | +LL | type Decoder; + | ^^^^^^^^^^^^^ required by this bound in `Decode::Decoder` +help: consider relaxing the implicit `Sized` restriction + | +LL | type Decoder: ?Sized; + | ++++++++ + +error[E0277]: the trait bound `NonImplementedStruct: NonImplementedTrait` is not satisfied + --> $DIR/dropck-normalize-errors.rs:27:22 + | +LL | non_implemented: ::Assoc, + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `NonImplementedTrait` is not implemented for `NonImplementedStruct` + | +help: this trait has no implementations, consider adding one + --> $DIR/dropck-normalize-errors.rs:7:1 + | +LL | trait NonImplementedTrait { + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + +error[E0277]: the trait bound `NonImplementedStruct: NonImplementedTrait` is not satisfied + --> $DIR/dropck-normalize-errors.rs:15:28 + | +LL | fn make_a_decoder<'a>() -> ADecoder<'a> { + | ^^^^^^^^^^^^ the trait `NonImplementedTrait` is not implemented for `NonImplementedStruct` + | +help: this trait has no implementations, consider adding one + --> $DIR/dropck-normalize-errors.rs:7:1 + | +LL | trait NonImplementedTrait { + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 4 previous errors + +For more information about this error, try `rustc --explain E0277`.