From ba0ecbdcd41879be9e5d3662c4c04c8e6c41f40b Mon Sep 17 00:00:00 2001 From: lcnr Date: Thu, 5 May 2022 09:37:50 +0200 Subject: [PATCH] forbid empty impls for types with incoherent impls --- .../src/coherence/inherent_impls.rs | 27 ++++- .../auxiliary/extern-crate.rs | 9 ++ .../needs-has-incoherent-impls.rs | 34 ++++++ .../needs-has-incoherent-impls.stderr | 105 ++++++++++++++++++ .../no-attr-empty-impl.rs | 14 +++ .../no-attr-empty-impl.stderr | 44 ++++++++ 6 files changed, 228 insertions(+), 5 deletions(-) create mode 100644 src/test/ui/incoherent-inherent-impls/auxiliary/extern-crate.rs create mode 100644 src/test/ui/incoherent-inherent-impls/needs-has-incoherent-impls.rs create mode 100644 src/test/ui/incoherent-inherent-impls/needs-has-incoherent-impls.stderr create mode 100644 src/test/ui/incoherent-inherent-impls/no-attr-empty-impl.rs create mode 100644 src/test/ui/incoherent-inherent-impls/no-attr-empty-impl.stderr diff --git a/compiler/rustc_typeck/src/coherence/inherent_impls.rs b/compiler/rustc_typeck/src/coherence/inherent_impls.rs index 8c2e91ab8f1e..d50ac7257102 100644 --- a/compiler/rustc_typeck/src/coherence/inherent_impls.rs +++ b/compiler/rustc_typeck/src/coherence/inherent_impls.rs @@ -122,6 +122,8 @@ impl<'tcx> ItemLikeVisitor<'_> for InherentCollect<'tcx> { const INTO_CORE: &str = "consider moving this inherent impl into `core` if possible"; const INTO_DEFINING_CRATE: &str = "consider moving this inherent impl into the crate defining the type if possible"; +const ADD_ATTR_TO_TY: &str = "alternatively add `#[rustc_has_incoherent_inherent_impls]` to the type \ + and `#[rustc_allow_incoherent_impl]` to the relevant impl items"; const ADD_ATTR: &str = "alternatively add `#[rustc_allow_incoherent_impl]` to the relevant impl items"; @@ -137,13 +139,28 @@ impl<'tcx> InherentCollect<'tcx> { return; } - if self.tcx.has_attr(def_id, sym::rustc_has_incoherent_inherent_impls) { - let hir::ItemKind::Impl(hir::Impl { items, .. }) = item.kind else { + if self.tcx.features().rustc_attrs { + let hir::ItemKind::Impl(&hir::Impl { items, .. }) = item.kind else { bug!("expected `impl` item: {:?}", item); }; - for item in items { - if !self.tcx.has_attr(item.id.def_id.to_def_id(), sym::rustc_allow_incoherent_impl) + if !self.tcx.has_attr(def_id, sym::rustc_has_incoherent_inherent_impls) { + struct_span_err!( + self.tcx.sess, + item.span, + E0390, + "cannot define inherent `impl` for a type outside of crate where the type is defined", + ) + .help(INTO_DEFINING_CRATE) + .span_help(item.span, ADD_ATTR_TO_TY) + .emit(); + return; + } + + for impl_item in items { + if !self + .tcx + .has_attr(impl_item.id.def_id.to_def_id(), sym::rustc_allow_incoherent_impl) { struct_span_err!( self.tcx.sess, @@ -152,7 +169,7 @@ impl<'tcx> InherentCollect<'tcx> { "cannot define inherent `impl` for a type outside of crate where the type is defined", ) .help(INTO_DEFINING_CRATE) - .span_help(item.span, ADD_ATTR) + .span_help(impl_item.span, ADD_ATTR) .emit(); return; } diff --git a/src/test/ui/incoherent-inherent-impls/auxiliary/extern-crate.rs b/src/test/ui/incoherent-inherent-impls/auxiliary/extern-crate.rs new file mode 100644 index 000000000000..22f0d912c8f8 --- /dev/null +++ b/src/test/ui/incoherent-inherent-impls/auxiliary/extern-crate.rs @@ -0,0 +1,9 @@ +#![feature(rustc_attrs)] + +#[rustc_has_incoherent_inherent_impls] +pub struct StructWithAttr; +pub struct StructNoAttr; + +#[rustc_has_incoherent_inherent_impls] +pub enum EnumWithAttr {} +pub enum EnumNoAttr {} diff --git a/src/test/ui/incoherent-inherent-impls/needs-has-incoherent-impls.rs b/src/test/ui/incoherent-inherent-impls/needs-has-incoherent-impls.rs new file mode 100644 index 000000000000..ce5200a50084 --- /dev/null +++ b/src/test/ui/incoherent-inherent-impls/needs-has-incoherent-impls.rs @@ -0,0 +1,34 @@ +// aux-build:extern-crate.rs +#![feature(rustc_attrs)] +extern crate extern_crate; + +impl extern_crate::StructWithAttr { //~ ERROR + fn foo() {} +} +impl extern_crate::StructWithAttr { + #[rustc_allow_incoherent_impl] + fn bar() {} +} +impl extern_crate::StructNoAttr { //~ ERROR + fn foo() {} +} +impl extern_crate::StructNoAttr { //~ ERROR + #[rustc_allow_incoherent_impl] + fn bar() {} +} +impl extern_crate::EnumWithAttr { //~ ERROR + fn foo() {} +} +impl extern_crate::EnumWithAttr { + #[rustc_allow_incoherent_impl] + fn bar() {} +} +impl extern_crate::EnumNoAttr { //~ ERROR + fn foo() {} +} +impl extern_crate::EnumNoAttr { //~ ERROR + #[rustc_allow_incoherent_impl] + fn bar() {} +} + +fn main() {} diff --git a/src/test/ui/incoherent-inherent-impls/needs-has-incoherent-impls.stderr b/src/test/ui/incoherent-inherent-impls/needs-has-incoherent-impls.stderr new file mode 100644 index 000000000000..1b0cadc2c28c --- /dev/null +++ b/src/test/ui/incoherent-inherent-impls/needs-has-incoherent-impls.stderr @@ -0,0 +1,105 @@ +error[E0390]: cannot define inherent `impl` for a type outside of crate where the type is defined + --> $DIR/needs-has-incoherent-impls.rs:5:1 + | +LL | / impl extern_crate::StructWithAttr { +LL | | fn foo() {} +LL | | } + | |_^ + | + = help: consider moving this inherent impl into the crate defining the type if possible +help: alternatively add `#[rustc_allow_incoherent_impl]` to the relevant impl items + --> $DIR/needs-has-incoherent-impls.rs:6:5 + | +LL | fn foo() {} + | ^^^^^^^^^^^ + +error[E0390]: cannot define inherent `impl` for a type outside of crate where the type is defined + --> $DIR/needs-has-incoherent-impls.rs:12:1 + | +LL | / impl extern_crate::StructNoAttr { +LL | | fn foo() {} +LL | | } + | |_^ + | + = help: consider moving this inherent impl into the crate defining the type if possible +help: alternatively add `#[rustc_has_incoherent_inherent_impls]` to the type and `#[rustc_allow_incoherent_impl]` to the relevant impl items + --> $DIR/needs-has-incoherent-impls.rs:12:1 + | +LL | / impl extern_crate::StructNoAttr { +LL | | fn foo() {} +LL | | } + | |_^ + +error[E0390]: cannot define inherent `impl` for a type outside of crate where the type is defined + --> $DIR/needs-has-incoherent-impls.rs:15:1 + | +LL | / impl extern_crate::StructNoAttr { +LL | | #[rustc_allow_incoherent_impl] +LL | | fn bar() {} +LL | | } + | |_^ + | + = help: consider moving this inherent impl into the crate defining the type if possible +help: alternatively add `#[rustc_has_incoherent_inherent_impls]` to the type and `#[rustc_allow_incoherent_impl]` to the relevant impl items + --> $DIR/needs-has-incoherent-impls.rs:15:1 + | +LL | / impl extern_crate::StructNoAttr { +LL | | #[rustc_allow_incoherent_impl] +LL | | fn bar() {} +LL | | } + | |_^ + +error[E0390]: cannot define inherent `impl` for a type outside of crate where the type is defined + --> $DIR/needs-has-incoherent-impls.rs:19:1 + | +LL | / impl extern_crate::EnumWithAttr { +LL | | fn foo() {} +LL | | } + | |_^ + | + = help: consider moving this inherent impl into the crate defining the type if possible +help: alternatively add `#[rustc_allow_incoherent_impl]` to the relevant impl items + --> $DIR/needs-has-incoherent-impls.rs:20:5 + | +LL | fn foo() {} + | ^^^^^^^^^^^ + +error[E0390]: cannot define inherent `impl` for a type outside of crate where the type is defined + --> $DIR/needs-has-incoherent-impls.rs:26:1 + | +LL | / impl extern_crate::EnumNoAttr { +LL | | fn foo() {} +LL | | } + | |_^ + | + = help: consider moving this inherent impl into the crate defining the type if possible +help: alternatively add `#[rustc_has_incoherent_inherent_impls]` to the type and `#[rustc_allow_incoherent_impl]` to the relevant impl items + --> $DIR/needs-has-incoherent-impls.rs:26:1 + | +LL | / impl extern_crate::EnumNoAttr { +LL | | fn foo() {} +LL | | } + | |_^ + +error[E0390]: cannot define inherent `impl` for a type outside of crate where the type is defined + --> $DIR/needs-has-incoherent-impls.rs:29:1 + | +LL | / impl extern_crate::EnumNoAttr { +LL | | #[rustc_allow_incoherent_impl] +LL | | fn bar() {} +LL | | } + | |_^ + | + = help: consider moving this inherent impl into the crate defining the type if possible +help: alternatively add `#[rustc_has_incoherent_inherent_impls]` to the type and `#[rustc_allow_incoherent_impl]` to the relevant impl items + --> $DIR/needs-has-incoherent-impls.rs:29:1 + | +LL | / impl extern_crate::EnumNoAttr { +LL | | #[rustc_allow_incoherent_impl] +LL | | fn bar() {} +LL | | } + | |_^ + +error: aborting due to 6 previous errors + +For more information about this error, try `rustc --explain E0390`. diff --git a/src/test/ui/incoherent-inherent-impls/no-attr-empty-impl.rs b/src/test/ui/incoherent-inherent-impls/no-attr-empty-impl.rs new file mode 100644 index 000000000000..6d11a7b89389 --- /dev/null +++ b/src/test/ui/incoherent-inherent-impls/no-attr-empty-impl.rs @@ -0,0 +1,14 @@ +// aux-build:extern-crate.rs +extern crate extern_crate; + +impl extern_crate::StructWithAttr {} //~ ERROR + +impl extern_crate::StructNoAttr {} //~ ERROR + +impl extern_crate::EnumWithAttr {} //~ ERROR + +impl extern_crate::EnumNoAttr {} //~ ERROR + +impl f32 {} //~ ERROR + +fn main() {} diff --git a/src/test/ui/incoherent-inherent-impls/no-attr-empty-impl.stderr b/src/test/ui/incoherent-inherent-impls/no-attr-empty-impl.stderr new file mode 100644 index 000000000000..b7fca9e98162 --- /dev/null +++ b/src/test/ui/incoherent-inherent-impls/no-attr-empty-impl.stderr @@ -0,0 +1,44 @@ +error[E0116]: cannot define inherent `impl` for a type outside of the crate where the type is defined + --> $DIR/no-attr-empty-impl.rs:4:1 + | +LL | impl extern_crate::StructWithAttr {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl for type defined outside of crate. + | + = note: define and implement a trait or new type instead + +error[E0116]: cannot define inherent `impl` for a type outside of the crate where the type is defined + --> $DIR/no-attr-empty-impl.rs:6:1 + | +LL | impl extern_crate::StructNoAttr {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl for type defined outside of crate. + | + = note: define and implement a trait or new type instead + +error[E0116]: cannot define inherent `impl` for a type outside of the crate where the type is defined + --> $DIR/no-attr-empty-impl.rs:8:1 + | +LL | impl extern_crate::EnumWithAttr {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl for type defined outside of crate. + | + = note: define and implement a trait or new type instead + +error[E0116]: cannot define inherent `impl` for a type outside of the crate where the type is defined + --> $DIR/no-attr-empty-impl.rs:10:1 + | +LL | impl extern_crate::EnumNoAttr {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl for type defined outside of crate. + | + = note: define and implement a trait or new type instead + +error[E0390]: cannot define inherent `impl` for primitive types + --> $DIR/no-attr-empty-impl.rs:12:6 + | +LL | impl f32 {} + | ^^^ + | + = help: consider using an extension trait instead + +error: aborting due to 5 previous errors + +Some errors have detailed explanations: E0116, E0390. +For more information about an error, try `rustc --explain E0116`.