rust-analyzer

diff --git a/crates/hir-ty/src/diagnostics.rs b/crates/hir-ty/src/diagnostics.rs
index ef43ed5c46..c1b3619009 100644
--- a/crates/hir-ty/src/diagnostics.rs
+++ b/crates/hir-ty/src/diagnostics.rs

@@ -11,9 +11,3 @@ pub use crate::diagnostics::{

unsafe_check::{missing_unsafe, unsafe_expressions, UnsafeExpr},

};

-#[derive(Debug, PartialEq, Eq)]

-pub struct IncoherentImpl {

- pub file_id: hir_expand::HirFileId,

- pub impl_: syntax::AstPtr<syntax::ast::Impl>,

diff --git a/crates/hir-ty/src/lib.rs b/crates/hir-ty/src/lib.rs
index 405bb001b5..35a3a1ad8d 100644
--- a/crates/hir-ty/src/lib.rs
+++ b/crates/hir-ty/src/lib.rs

@@ -80,6 +80,7 @@ pub use mapping::{

lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id, to_foreign_def_id,

to_placeholder_idx,

};

+pub use method_resolution::check_orphan_rules;

pub use traits::TraitEnvironment;

pub use utils::{all_super_traits, is_fn_unsafe_to_call};

diff --git a/crates/hir-ty/src/method_resolution.rs b/crates/hir-ty/src/method_resolution.rs
index f3a5f69b2a..87c9328336 100644
--- a/crates/hir-ty/src/method_resolution.rs
+++ b/crates/hir-ty/src/method_resolution.rs

@@ -862,6 +862,62 @@ fn is_inherent_impl_coherent(

}

+/// Checks whether the impl satisfies the orphan rules.

+///

+/// Given `impl<P1..=Pn> Trait<T1..=Tn> for T0`, an `impl`` is valid only if at least one of the following is true:

+/// - Trait is a local trait

+/// - All of

+/// - At least one of the types `T0..=Tn`` must be a local type. Let `Ti`` be the first such type.

+/// - No uncovered type parameters `P1..=Pn` may appear in `T0..Ti`` (excluding `Ti`)

+pub fn check_orphan_rules(db: &dyn HirDatabase, impl_: ImplId) -> bool {

+ let substs = TyBuilder::placeholder_subst(db, impl_);

+ let Some(impl_trait) = db.impl_trait(impl_) else {

+ // not a trait impl

+ return true;

+ };

+ let local_crate = impl_.lookup(db.upcast()).container.krate();

+ let is_local = |tgt_crate| tgt_crate == local_crate;

+ let trait_ref = impl_trait.substitute(Interner, &substs);

+ let trait_id = from_chalk_trait_id(trait_ref.trait_id);

+ if is_local(trait_id.module(db.upcast()).krate()) {

+ // trait to be implemented is local

+ return true;

+ }

+ let unwrap_fundamental = |ty: Ty| match ty.kind(Interner) {

+ TyKind::Ref(_, _, referenced) => referenced.clone(),

+ &TyKind::Adt(AdtId(hir_def::AdtId::StructId(s)), ref subs) => {

+ let struct_data = db.struct_data(s);

+ if struct_data.flags.contains(StructFlags::IS_FUNDAMENTAL) {

+ let next = subs.type_parameters(Interner).next();

+ match next {

+ Some(ty) => ty,

+ None => ty,

+ }

+ } else {

+ ty

+ }

+ _ => ty,

+ };

+ // - At least one of the types `T0..=Tn`` must be a local type. Let `Ti`` be the first such type.

+ let is_not_orphan = trait_ref.substitution.type_parameters(Interner).any(|ty| {

+ match unwrap_fundamental(ty).kind(Interner) {

+ &TyKind::Adt(AdtId(id), _) => is_local(id.module(db.upcast()).krate()),

+ TyKind::Error => true,

+ TyKind::Dyn(it) => it.principal().map_or(false, |trait_ref| {

+ is_local(from_chalk_trait_id(trait_ref.trait_id).module(db.upcast()).krate())

+ }),

+ _ => false,

+ }

+ });

+ // FIXME: param coverage

+ // - No uncovered type parameters `P1..=Pn` may appear in `T0..Ti`` (excluding `Ti`)

+ is_not_orphan

pub fn iterate_path_candidates(

ty: &Canonical<Ty>,

db: &dyn HirDatabase,

diff --git a/crates/hir/src/diagnostics.rs b/crates/hir/src/diagnostics.rs
index 67d3169243..3a45622675 100644
--- a/crates/hir/src/diagnostics.rs
+++ b/crates/hir/src/diagnostics.rs

@@ -3,7 +3,7 @@

//!

//! This probably isn't the best way to do this -- ideally, diagnostics should

//! be expressed in terms of hir types themselves.

-pub use hir_ty::diagnostics::{CaseType, IncoherentImpl, IncorrectCase};

+pub use hir_ty::diagnostics::{CaseType, IncorrectCase};

use base_db::CrateId;

use cfg::{CfgExpr, CfgOptions};

@@ -38,6 +38,7 @@ diagnostics![

IncorrectCase,

InvalidDeriveTarget,

IncoherentImpl,

+ TraitImplOrphan,

MacroDefError,

MacroError,

MacroExpansionParseError,

@@ -280,3 +281,15 @@ pub struct MovedOutOfRef {

pub ty: Type,

pub span: InFile<SyntaxNodePtr>,

}

+#[derive(Debug, PartialEq, Eq)]

+pub struct IncoherentImpl {

+ pub file_id: HirFileId,

+ pub impl_: AstPtr<ast::Impl>,

+#[derive(Debug, PartialEq, Eq)]

+pub struct TraitImplOrphan {

+ pub file_id: HirFileId,

+ pub impl_: AstPtr<ast::Impl>,

diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 6fcc02fb9d..dfb0779f10 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs

@@ -60,7 +60,7 @@ use hir_def::{

};

use hir_expand::{name::name, MacroCallKind};

use hir_ty::{

- all_super_traits, autoderef,

+ all_super_traits, autoderef, check_orphan_rules,

consteval::{try_const_usize, unknown_const_as_generic, ConstEvalError, ConstExt},

diagnostics::BodyValidationDiagnostic,

known_const_to_ast,

@@ -95,7 +95,7 @@ pub use crate::{

MacroExpansionParseError, MalformedDerive, MismatchedArgCount,

MismatchedTupleStructPatArgCount, MissingFields, MissingMatchArms, MissingUnsafe,

MovedOutOfRef, NeedMut, NoSuchField, PrivateAssocItem, PrivateField,

- ReplaceFilterMapNextWithFindMap, TypeMismatch, TypedHole, UndeclaredLabel,

+ ReplaceFilterMapNextWithFindMap, TraitImplOrphan, TypeMismatch, TypedHole, UndeclaredLabel,

UnimplementedBuiltinMacro, UnreachableLabel, UnresolvedExternCrate, UnresolvedField,

UnresolvedImport, UnresolvedMacroCall, UnresolvedMethodCall, UnresolvedModule,

UnresolvedProcMacro, UnusedMut, UnusedVariable,

@@ -624,6 +624,11 @@ impl Module {

acc.push(IncoherentImpl { impl_: ast_id_map.get(node.ast_id()), file_id }.into())

}

+ if !impl_def.check_orphan_rules(db) {

+ let ast_id_map = db.ast_id_map(file_id);

+ acc.push(TraitImplOrphan { impl_: ast_id_map.get(node.ast_id()), file_id }.into())

+ }

for item in impl_def.items(db) {

let def: DefWithBody = match item {

AssocItem::Function(it) => it.into(),

@@ -3406,6 +3411,10 @@ impl Impl {

let src = self.source(db)?;

src.file_id.as_builtin_derive_attr_node(db.upcast())

}

+ pub fn check_orphan_rules(self, db: &dyn HirDatabase) -> bool {

+ check_orphan_rules(db, self.id)

+ }

}

#[derive(Clone, PartialEq, Eq, Debug, Hash)]

diff --git a/crates/ide-diagnostics/src/handlers/trait_impl_orphan.rs b/crates/ide-diagnostics/src/handlers/trait_impl_orphan.rs
new file mode 100644
index 0000000000..159d87d269
--- /dev/null
+++ b/crates/ide-diagnostics/src/handlers/trait_impl_orphan.rs

@@ -0,0 +1,106 @@

+use hir::InFile;

+use crate::{Diagnostic, DiagnosticCode, DiagnosticsContext};

+// Diagnostic: trait-impl-orphan

+//

+// Only traits defined in the current crate can be implemented for arbitrary types

+pub(crate) fn trait_impl_orphan(

+ ctx: &DiagnosticsContext<'_>,

+ d: &hir::TraitImplOrphan,

+) -> Diagnostic {

+ Diagnostic::new_with_syntax_node_ptr(

+ ctx,

+ DiagnosticCode::RustcHardError("E0117"),

+ format!("only traits defined in the current crate can be implemented for arbitrary types"),

+ InFile::new(d.file_id, d.impl_.clone().into()),

+ )

+ // Not yet checked for false positives

+ .experimental()

+#[cfg(test)]

+mod tests {

+ use crate::tests::check_diagnostics;

+ #[test]

+ fn simple() {

+ check_diagnostics(

+ r#"

+//- /foo.rs crate:foo

+pub trait Foo {}

+//- /bar.rs crate:bar

+pub struct Bar;

+//- /main.rs crate:main deps:foo,bar

+struct LocalType;

+trait LocalTrait {}

+ impl foo::Foo for bar::Bar {}

+//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: only traits defined in the current crate can be implemented for arbitrary types

+impl foo::Foo for LocalType {}

+impl LocalTrait for bar::Bar {}

+"#,

+ );

+ }

+ #[test]

+ fn generics() {

+ check_diagnostics(

+ r#"

+//- /foo.rs crate:foo

+pub trait Foo<T> {}

+//- /bar.rs crate:bar

+pub struct Bar<T>(T);

+//- /main.rs crate:main deps:foo,bar

+struct LocalType<T>;

+trait LocalTrait<T> {}

+ impl<T> foo::Foo<T> for bar::Bar<T> {}

+//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: only traits defined in the current crate can be implemented for arbitrary types

+ impl<T> foo::Foo<T> for bar::Bar<LocalType<T>> {}

+//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: only traits defined in the current crate can be implemented for arbitrary types

+ impl<T> foo::Foo<LocalType<T>> for bar::Bar<T> {}

+ impl<T> foo::Foo<bar::Bar<LocalType<T>>> for bar::Bar<LocalType<T>> {}

+//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: only traits defined in the current crate can be implemented for arbitrary types

+"#,

+ );

+ }

+ #[test]

+ fn fundamental() {

+ check_diagnostics(

+ r#"

+//- /foo.rs crate:foo

+pub trait Foo<T> {}

+//- /bar.rs crate:bar

+pub struct Bar<T>(T);

+#[lang = "owned_box"]

+#[fundamental]

+pub struct Box<T>(T);

+//- /main.rs crate:main deps:foo,bar

+struct LocalType;

+ impl<T> foo::Foo<T> for bar::Box<T> {}

+//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: only traits defined in the current crate can be implemented for arbitrary types

+ impl<T> foo::Foo<T> for &LocalType {}

+ impl<T> foo::Foo<T> for bar::Box<LocalType> {}

+"#,

+ );

+ }

+ #[test]

+ fn dyn_object() {

+ check_diagnostics(

+ r#"

+//- /foo.rs crate:foo

+pub trait Foo<T> {}

+//- /bar.rs crate:bar

+pub struct Bar;

+//- /main.rs crate:main deps:foo,bar

+trait LocalTrait {}

+impl<T> foo::Foo<T> for dyn LocalTrait {}

+impl<T> foo::Foo<dyn LocalTrait> for Bar {}

+"#,

+ );

+ }

diff --git a/crates/ide-diagnostics/src/lib.rs b/crates/ide-diagnostics/src/lib.rs
index 68d7e99b7b..3226dd29d2 100644
--- a/crates/ide-diagnostics/src/lib.rs
+++ b/crates/ide-diagnostics/src/lib.rs

@@ -44,6 +44,7 @@ mod handlers {

pub(crate) mod private_assoc_item;

pub(crate) mod private_field;

pub(crate) mod replace_filter_map_next_with_find_map;

+ pub(crate) mod trait_impl_orphan;

pub(crate) mod typed_hole;

pub(crate) mod type_mismatch;

pub(crate) mod unimplemented_builtin_macro;

@@ -301,9 +302,9 @@ pub fn diagnostics(

)

}));

- let parse = parse.syntax_node();

+ let parse = sema.parse(file_id);

- for node in parse.descendants() {

+ for node in parse.syntax().descendants() {

handlers::useless_braces::useless_braces(&mut res, file_id, &node);

handlers::field_shorthand::field_shorthand(&mut res, file_id, &node);

handlers::json_is_not_rust::json_in_items(&sema, &mut res, file_id, &node, config);

@@ -358,6 +359,7 @@ pub fn diagnostics(

AnyDiagnostic::PrivateAssocItem(d) => handlers::private_assoc_item::private_assoc_item(&ctx, &d),

AnyDiagnostic::PrivateField(d) => handlers::private_field::private_field(&ctx, &d),

AnyDiagnostic::ReplaceFilterMapNextWithFindMap(d) => handlers::replace_filter_map_next_with_find_map::replace_filter_map_next_with_find_map(&ctx, &d),

+ AnyDiagnostic::TraitImplOrphan(d) => handlers::trait_impl_orphan::trait_impl_orphan(&ctx, &d),

AnyDiagnostic::TypedHole(d) => handlers::typed_hole::typed_hole(&ctx, &d),

AnyDiagnostic::TypeMismatch(d) => handlers::type_mismatch::type_mismatch(&ctx, &d),

AnyDiagnostic::UndeclaredLabel(d) => handlers::undeclared_label::undeclared_label(&ctx, &d),

@@ -386,7 +388,7 @@ pub fn diagnostics(

handle_lint_attributes(

&ctx.sema,

- &parse,

+ parse.syntax(),

&mut rustc_stack,

&mut clippy_stack,

&mut diagnostics_of_range,

diff --git a/crates/ide-diagnostics/src/tests.rs b/crates/ide-diagnostics/src/tests.rs
index ee0e035490..ff8f3b2686 100644
--- a/crates/ide-diagnostics/src/tests.rs
+++ b/crates/ide-diagnostics/src/tests.rs

@@ -5,7 +5,7 @@ use expect_test::Expect;

use ide_db::{

assists::AssistResolveStrategy,

base_db::{fixture::WithFixture, SourceDatabaseExt},

- RootDatabase,

+ LineIndexDatabase, RootDatabase,

};

use stdx::trim_indent;

use test_utils::{assert_eq_text, extract_annotations, MiniCore};

@@ -103,6 +103,7 @@ pub(crate) fn check_diagnostics(ra_fixture: &str) {

pub(crate) fn check_diagnostics_with_config(config: DiagnosticsConfig, ra_fixture: &str) {

let (db, files) = RootDatabase::with_many_files(ra_fixture);

for file_id in files {

+ let line_index = db.line_index(file_id);

let diagnostics = super::diagnostics(&db, &config, &AssistResolveStrategy::All, file_id);

let expected = extract_annotations(&db.file_text(file_id));

@@ -136,8 +137,16 @@ pub(crate) fn check_diagnostics_with_config(config: DiagnosticsConfig, ra_fixtur

}

if expected != actual {

- let fneg = expected.iter().filter(|x| !actual.contains(x)).collect::<Vec<_>>();

- let fpos = actual.iter().filter(|x| !expected.contains(x)).collect::<Vec<_>>();

+ let fneg = expected

+ .iter()

+ .filter(|x| !actual.contains(x))

+ .map(|(range, s)| (line_index.line_col(range.start()), range, s))

+ .collect::<Vec<_>>();

+ let fpos = actual

+ .iter()

+ .filter(|x| !expected.contains(x))

+ .map(|(range, s)| (line_index.line_col(range.start()), range, s))

+ .collect::<Vec<_>>();

panic!("Diagnostic test failed.\nFalse negatives: {fneg:?}\nFalse positives: {fpos:?}");

}