diff options
| -rw-r--r-- | compiler/rustc_symbol_mangling/src/v0.rs | 43 | ||||
| -rw-r--r-- | compiler/rustc_typeck/src/astconv/mod.rs | 4 | ||||
| -rw-r--r-- | src/test/ui/symbol-names/trait-objects.rs | 48 | ||||
| -rw-r--r-- | src/test/ui/symbol-names/trait-objects.v0.stderr | 56 |
4 files changed, 144 insertions, 7 deletions
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs index 37a834043f6..a70b374fc6d 100644 --- a/compiler/rustc_symbol_mangling/src/v0.rs +++ b/compiler/rustc_symbol_mangling/src/v0.rs @@ -485,9 +485,39 @@ impl Printer<'tcx> for SymbolMangler<'tcx> { mut self, predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>, ) -> Result<Self::DynExistential, Self::Error> { - for predicate in predicates { - self = self.in_binder(&predicate, |mut cx, predicate| { - match predicate { + // Okay, so this is a bit tricky. Imagine we have a trait object like + // `dyn for<'a> Foo<'a, Bar = &'a ()>`. When we mangle this, the + // output looks really close to the syntax, where the `Bar = &'a ()` bit + // is under the same binders (`['a]`) as the `Foo<'a>` bit. However, we + // actually desugar these into two separate `ExistentialPredicate`s. We + // can't enter/exit the "binder scope" twice though, because then we + // would mangle the binders twice. (Also, side note, we merging these + // two is kind of difficult, because of potential HRTBs in the Projection + // predicate.) + // + // Also worth mentioning: imagine that we instead had + // `dyn for<'a> Foo<'a, Bar = &'a ()> + Send`. In this case, `Send` is + // under the same binders as `Foo`. Currently, this doesn't matter, + // because only *auto traits* are allowed other than the principal trait + // and all auto traits don't have any generics. Two things could + // make this not an "okay" mangling: + // 1) Instead of mangling only *used* + // bound vars, we want to mangle *all* bound vars (`for<'b> Send` is a + // valid trait predicate); + // 2) We allow multiple "principal" traits in the future, or at least + // allow in any form another trait predicate that can take generics. + // + // Here we assume that predicates have the following structure: + // [<Trait> [{<Projection>}]] [{<Auto>}] + // Since any predicates after the first one shouldn't change the binders, + // just put them all in the binders of the first. + self = self.in_binder(&predicates[0], |mut cx, _| { + for predicate in predicates.iter() { + // It would be nice to be able to validate bound vars here, but + // projections can actually include bound vars from super traits + // because of HRTBs (only in the `Self` type). Also, auto traits + // could have different bound vars *anyways*. + match predicate.as_ref().skip_binder() { ty::ExistentialPredicate::Trait(trait_ref) => { // Use a type that can't appear in defaults of type parameters. let dummy_self = cx.tcx.mk_ty_infer(ty::FreshTy(0)); @@ -504,9 +534,10 @@ impl Printer<'tcx> for SymbolMangler<'tcx> { cx = cx.print_def_path(*def_id, &[])?; } } - Ok(cx) - })?; - } + } + Ok(cx) + })?; + self.push("E"); Ok(self) } diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs index 5285c1c8598..ef195621044 100644 --- a/compiler/rustc_typeck/src/astconv/mod.rs +++ b/compiler/rustc_typeck/src/astconv/mod.rs @@ -1394,11 +1394,13 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { let auto_trait_predicates = auto_traits.into_iter().map(|trait_ref| { ty::Binder::dummy(ty::ExistentialPredicate::AutoTrait(trait_ref.trait_ref().def_id())) }); + // N.b. principal, projections, auto traits + // FIXME: This is actually wrong with multiple principals in regards to symbol mangling let mut v = regular_trait_predicates - .chain(auto_trait_predicates) .chain( existential_projections.map(|x| x.map_bound(ty::ExistentialPredicate::Projection)), ) + .chain(auto_trait_predicates) .collect::<SmallVec<[_; 8]>>(); v.sort_by(|a, b| a.skip_binder().stable_cmp(tcx, &b.skip_binder())); v.dedup(); diff --git a/src/test/ui/symbol-names/trait-objects.rs b/src/test/ui/symbol-names/trait-objects.rs new file mode 100644 index 00000000000..cea1a89d757 --- /dev/null +++ b/src/test/ui/symbol-names/trait-objects.rs @@ -0,0 +1,48 @@ +// Ensure that trait objects don't include more than one binder. See #83611 + +// build-fail +// revisions: v0 +//[v0]compile-flags: -Z symbol-mangling-version=v0 +//[v0]normalize-stderr-test: "Cs.*?_" -> "CRATE_HASH" +//[v0]normalize-stderr-test: "core\[.*?\]" -> "core[HASH]" + +#![feature(rustc_attrs)] + +trait Bar { + fn method(&self) {} +} + +impl Bar for &dyn FnMut(&u8) { + #[rustc_symbol_name] + //[v0]~^ ERROR symbol-name + //[v0]~| ERROR demangling + //[v0]~| ERROR demangling-alt + fn method(&self) {} +} + +trait Foo { + fn method(&self) {} +} + +impl Foo for &(dyn FnMut(&u8) + for<'b> Send) { + #[rustc_symbol_name] + //[v0]~^ ERROR symbol-name + //[v0]~| ERROR demangling + //[v0]~| ERROR demangling-alt + fn method(&self) {} +} + +trait Baz { + fn method(&self) {} +} + +impl Baz for &(dyn for<'b> Send + FnMut(&u8)) { + #[rustc_symbol_name] + //[v0]~^ ERROR symbol-name + //[v0]~| ERROR demangling + //[v0]~| ERROR demangling-alt + fn method(&self) {} +} + +fn main() { +} diff --git a/src/test/ui/symbol-names/trait-objects.v0.stderr b/src/test/ui/symbol-names/trait-objects.v0.stderr new file mode 100644 index 00000000000..2b09318f06c --- /dev/null +++ b/src/test/ui/symbol-names/trait-objects.v0.stderr @@ -0,0 +1,56 @@ +error: symbol-name(_RNvXCRATE_HASH13trait_objectsRDG_INtNtNtCRATE_HASH4core3ops8function5FnMutTRL0_hEEp6OutputuEL_NtB2_3Bar6method) + --> $DIR/trait-objects.rs:16:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: demangling(<&dyn for<'a> core[HASH]::ops::function::FnMut<(&'a u8,), Output = ()> as trait_objects[17891616a171812d]::Bar>::method) + --> $DIR/trait-objects.rs:16:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: demangling-alt(<&dyn for<'a> core::ops::function::FnMut<(&'a u8,), Output = ()> as trait_objects::Bar>::method) + --> $DIR/trait-objects.rs:16:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: symbol-name(_RNvXs_CRATE_HASH13trait_objectsRDG_INtNtNtCRATE_HASH4core3ops8function5FnMutTRL0_hEEp6OutputuNtNtBI_6marker4SendEL_NtB4_3Foo6method) + --> $DIR/trait-objects.rs:28:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: demangling(<&dyn for<'a> core[HASH]::ops::function::FnMut<(&'a u8,), Output = ()> + core[HASH]::marker::Send as trait_objects[17891616a171812d]::Foo>::method) + --> $DIR/trait-objects.rs:28:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: demangling-alt(<&dyn for<'a> core::ops::function::FnMut<(&'a u8,), Output = ()> + core::marker::Send as trait_objects::Foo>::method) + --> $DIR/trait-objects.rs:28:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: symbol-name(_RNvXs0_CRATE_HASH13trait_objectsRDG_INtNtNtCRATE_HASH4core3ops8function5FnMutTRL0_hEEp6OutputuNtNtBJ_6marker4SendEL_NtB5_3Baz6method) + --> $DIR/trait-objects.rs:40:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: demangling(<&dyn for<'a> core[HASH]::ops::function::FnMut<(&'a u8,), Output = ()> + core[HASH]::marker::Send as trait_objects[17891616a171812d]::Baz>::method) + --> $DIR/trait-objects.rs:40:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: demangling-alt(<&dyn for<'a> core::ops::function::FnMut<(&'a u8,), Output = ()> + core::marker::Send as trait_objects::Baz>::method) + --> $DIR/trait-objects.rs:40:5 + | +LL | #[rustc_symbol_name] + | ^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 9 previous errors + |