diff options
| -rw-r--r-- | compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs | 34 | ||||
| -rw-r--r-- | tests/crashes/121816.rs | 12 | ||||
| -rw-r--r-- | tests/ui/borrowck/ice-on-non-ref-sig-ty.rs | 19 | ||||
| -rw-r--r-- | tests/ui/borrowck/ice-on-non-ref-sig-ty.stderr | 36 |
4 files changed, 81 insertions, 20 deletions
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs index b147567001d..2d9bc45ebc8 100644 --- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs @@ -4304,17 +4304,35 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> { // search for relevant arguments. let mut arguments = Vec::new(); for (index, argument) in sig.inputs().skip_binder().iter().enumerate() { - if let ty::Ref(argument_region, _, _) = argument.kind() { - if argument_region == return_region { - // Need to use the `rustc_middle::ty` types to compare against the - // `return_region`. Then use the `rustc_hir` type to get only - // the lifetime span. - if let hir::TyKind::Ref(lifetime, _) = &fn_decl.inputs[index].kind { + if let ty::Ref(argument_region, _, _) = argument.kind() + && argument_region == return_region + { + // Need to use the `rustc_middle::ty` types to compare against the + // `return_region`. Then use the `rustc_hir` type to get only + // the lifetime span. + match &fn_decl.inputs[index].kind { + hir::TyKind::Ref(lifetime, _) => { // With access to the lifetime, we can get // the span of it. arguments.push((*argument, lifetime.ident.span)); - } else { - bug!("ty type is a ref but hir type is not"); + } + // Resolve `self` whose self type is `&T`. + hir::TyKind::Path(hir::QPath::Resolved(None, path)) => { + if let Res::SelfTyAlias { alias_to, .. } = path.res + && let Some(alias_to) = alias_to.as_local() + && let hir::Impl { self_ty, .. } = self + .infcx + .tcx + .hir_node_by_def_id(alias_to) + .expect_item() + .expect_impl() + && let hir::TyKind::Ref(lifetime, _) = self_ty.kind + { + arguments.push((*argument, lifetime.ident.span)); + } + } + _ => { + // Don't ICE though. It might be a type alias. } } } diff --git a/tests/crashes/121816.rs b/tests/crashes/121816.rs deleted file mode 100644 index a5569ea19d3..00000000000 --- a/tests/crashes/121816.rs +++ /dev/null @@ -1,12 +0,0 @@ -//@ known-bug: #121816 -fn f<'a, T>(_: &'static &'a (), x: &'a T) -> &'static T { - x -} -trait W<'a> { - fn g<T>(self, x: &'a T) -> &'static T; -} -impl<'a> W<'a> for &'static () { - fn g<T>(self, x: &'a T) -> &'static T { - f(&self, x) - } -} diff --git a/tests/ui/borrowck/ice-on-non-ref-sig-ty.rs b/tests/ui/borrowck/ice-on-non-ref-sig-ty.rs new file mode 100644 index 00000000000..1c867bd2378 --- /dev/null +++ b/tests/ui/borrowck/ice-on-non-ref-sig-ty.rs @@ -0,0 +1,19 @@ +// Don't ICE when trying to annotate signature and we see `&()` + +fn f<'a, T>(_: &'static &'a (), x: &'a T) -> &'static T { + x +} +trait W<'a> { + fn g<T>(self, x: &'a T) -> &'static T; +} + +// Frankly this error message is impossible to parse, but :shrug:. +impl<'a> W<'a> for &'static () { + fn g<T>(self, x: &'a T) -> &'static T { + f(&self, x) + //~^ ERROR borrowed data escapes outside of method + //~| ERROR `self` does not live long enough + } +} + +fn main() {} diff --git a/tests/ui/borrowck/ice-on-non-ref-sig-ty.stderr b/tests/ui/borrowck/ice-on-non-ref-sig-ty.stderr new file mode 100644 index 00000000000..2b900a8e68a --- /dev/null +++ b/tests/ui/borrowck/ice-on-non-ref-sig-ty.stderr @@ -0,0 +1,36 @@ +error[E0521]: borrowed data escapes outside of method + --> $DIR/ice-on-non-ref-sig-ty.rs:13:9 + | +LL | impl<'a> W<'a> for &'static () { + | -- lifetime `'a` defined here +LL | fn g<T>(self, x: &'a T) -> &'static T { + | ---- - `x` is a reference that is only valid in the method body + | | + | `self` declared here, outside of the method body +LL | f(&self, x) + | ^^^^^^^^^^^ + | | + | `x` escapes the method body here + | argument requires that `'a` must outlive `'static` + +error[E0597]: `self` does not live long enough + --> $DIR/ice-on-non-ref-sig-ty.rs:13:11 + | +LL | impl<'a> W<'a> for &'static () { + | ------- has lifetime `'static` +LL | fn g<T>(self, x: &'a T) -> &'static T { + | ------- also has lifetime `'static` +LL | f(&self, x) + | ^^^^^ `self` would have to be valid for `'static`... +... +LL | } + | - ...but `self` will be dropped here, when the function `g` returns + | + = help: use data from the highlighted arguments which match the `'static` lifetime of the return type + = note: functions cannot return a borrow to data owned within the function's scope, functions can only return borrows to data passed as arguments + = note: to learn more, visit <https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html#dangling-references> + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0521, E0597. +For more information about an error, try `rustc --explain E0521`. |