Rollup merge of #90202 - matthewjasper:xcrate-hygiene, r=petrochenkov

Improve and test cross-crate hygiene

- Decode the parent expansion for traits and enums in `rustc_resolve`, this was already being used for resolution in typeck
- Avoid suggesting importing names with def-site hygiene, since it's often not useful
- Add more tests

r? `@petrochenkov`

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -1198,8 +1198,8 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             }
         }
 
-        if let EntryKind::Mod(data) = kind {
-            for exp in data.decode((self, sess)).reexports.decode((self, sess)) {
+        if let EntryKind::Mod(exports) = kind {
+            for exp in exports.decode((self, sess)) {
                 match exp.res {
                     Res::Def(DefKind::Macro(..), _) => {}
                     _ if macros_only => continue,
@@ -1219,10 +1219,11 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     }
 
     fn module_expansion(&self, id: DefIndex, sess: &Session) -> ExpnId {
-        if let EntryKind::Mod(m) = self.kind(id) {
-            m.decode((self, sess)).expansion
-        } else {
-            panic!("Expected module, found {:?}", self.local_def_id(id))
+        match self.kind(id) {
+            EntryKind::Mod(_) | EntryKind::Enum(_) | EntryKind::Trait(_) => {
+                self.get_expn_that_defined(id, sess)
+            }
+            _ => panic!("Expected module, found {:?}", self.local_def_id(id)),
         }
     }
 

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1086,11 +1086,11 @@ impl EncodeContext<'a, 'tcx> {
             Lazy::empty()
         };
 
-        let data = ModData { reexports, expansion: tcx.expn_that_defined(local_def_id) };
-
-        record!(self.tables.kind[def_id] <- EntryKind::Mod(self.lazy(data)));
+        record!(self.tables.kind[def_id] <- EntryKind::Mod(reexports));
         if self.is_proc_macro {
             record!(self.tables.children[def_id] <- &[]);
+            // Encode this here because we don't do it in encode_def_ids.
+            record!(self.tables.expn_that_defined[def_id] <- tcx.expn_that_defined(local_def_id));
         } else {
             record!(self.tables.children[def_id] <- md.item_ids.iter().map(|item_id| {
                 item_id.def_id.local_def_index

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -346,7 +346,7 @@ enum EntryKind {
     Union(Lazy<VariantData>, ReprOptions),
     Fn(Lazy<FnData>),
     ForeignFn(Lazy<FnData>),
-    Mod(Lazy<ModData>),
+    Mod(Lazy<[Export]>),
     MacroDef(Lazy<MacroDef>),
     ProcMacro(MacroKind),
     Closure,
@@ -364,12 +364,6 @@ enum EntryKind {
 #[derive(Encodable, Decodable)]
 struct RenderedConst(String);
 
-#[derive(MetadataEncodable, MetadataDecodable)]
-struct ModData {
-    reexports: Lazy<[Export]>,
-    expansion: ExpnId,
-}
-
 #[derive(MetadataEncodable, MetadataDecodable)]
 struct FnData {
     asyncness: hir::IsAsync,

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -145,17 +145,11 @@ impl<'a> Resolver<'a> {
                     } else {
                         def_key.disambiguated_data.data.get_opt_name().expect("module without name")
                     };
-                    let expn_id = if def_kind == DefKind::Mod {
-                        self.cstore().module_expansion_untracked(def_id, &self.session)
-                    } else {
-                        // FIXME: Parent expansions for enums and traits are not kept in metadata.
-                        ExpnId::root()
-                    };
 
                     Some(self.new_module(
                         parent,
                         ModuleKind::Def(def_kind, def_id, name),
-                        expn_id,
+                        self.cstore().module_expansion_untracked(def_id, &self.session),
                         self.cstore().get_span_untracked(def_id, &self.session),
                         // FIXME: Account for `#[no_implicit_prelude]` attributes.
                         parent.map_or(false, |module| module.no_implicit_prelude),

compiler/rustc_resolve/src/diagnostics.rs

@@ -842,9 +842,11 @@ impl<'a> Resolver<'a> {
 
                 // collect results based on the filter function
                 // avoid suggesting anything from the same module in which we are resolving
+                // avoid suggesting anything with a hygienic name
                 if ident.name == lookup_ident.name
                     && ns == namespace
                     && !ptr::eq(in_module, parent_scope.module)
+                    && !ident.span.normalize_to_macros_2_0().from_expansion()
                 {
                     let res = name_binding.res();
                     if filter_fn(res) {

compiler/rustc_span/src/hygiene.rs

@@ -709,7 +709,7 @@ impl SyntaxContext {
     ///         pub fn f() {} // `f`'s `SyntaxContext` has a single `ExpnId` from `m`.
     ///         pub fn $i() {} // `$i`'s `SyntaxContext` is empty.
     ///     }
-    ///     n(f);
+    ///     n!(f);
     ///     macro n($j:ident) {
     ///         use foo::*;
     ///         f(); // `f`'s `SyntaxContext` has a mark from `m` and a mark from `n`

src/test/ui/hygiene/auxiliary/fields.rs

@@ -0,0 +1,73 @@
+#![feature(decl_macro)]
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum Field {
+    RootCtxt,
+    MacroCtxt,
+}
+
+#[rustfmt::skip]
+macro x(
+    $macro_name:ident,
+    $macro2_name:ident,
+    $type_name:ident,
+    $field_name:ident,
+    $const_name:ident
+) {
+    #[derive(Copy, Clone)]
+    pub struct $type_name {
+        pub field: Field,
+        pub $field_name: Field,
+    }
+
+    pub const $const_name: $type_name =
+        $type_name { field: Field::MacroCtxt, $field_name: Field::RootCtxt };
+
+    #[macro_export]
+    macro_rules! $macro_name {
+        (check_fields_of $e:expr) => {{
+            let e = $e;
+            assert_eq!(e.field, Field::MacroCtxt);
+            assert_eq!(e.$field_name, Field::RootCtxt);
+        }};
+        (check_fields) => {{
+            assert_eq!($const_name.field, Field::MacroCtxt);
+            assert_eq!($const_name.$field_name, Field::RootCtxt);
+        }};
+        (construct) => {
+            $type_name { field: Field::MacroCtxt, $field_name: Field::RootCtxt }
+        };
+    }
+
+    pub macro $macro2_name {
+        (check_fields_of $e:expr) => {{
+            let e = $e;
+            assert_eq!(e.field, Field::MacroCtxt);
+            assert_eq!(e.$field_name, Field::RootCtxt);
+        }},
+        (check_fields) => {{
+            assert_eq!($const_name.field, Field::MacroCtxt);
+            assert_eq!($const_name.$field_name, Field::RootCtxt);
+        }},
+        (construct) => {
+            $type_name { field: Field::MacroCtxt, $field_name: Field::RootCtxt }
+        }
+    }
+}
+
+x!(test_fields, test_fields2, MyStruct, field, MY_CONST);
+
+pub fn check_fields(s: MyStruct) {
+    test_fields!(check_fields_of s);
+}
+
+pub fn check_fields_local() {
+    test_fields!(check_fields);
+    test_fields2!(check_fields);
+
+    let s1 = test_fields!(construct);
+    test_fields!(check_fields_of s1);
+
+    let s2 = test_fields2!(construct);
+    test_fields2!(check_fields_of s2);
+}

src/test/ui/hygiene/auxiliary/methods.rs

@@ -0,0 +1,160 @@
+#![feature(decl_macro)]
+
+#[derive(PartialEq, Eq, Debug)]
+pub enum Method {
+    DefaultMacroCtxt,
+    DefaultRootCtxt,
+    OverrideMacroCtxt,
+    OverrideRootCtxt,
+}
+
+#[rustfmt::skip]
+macro x($macro_name:ident, $macro2_name:ident, $trait_name:ident, $method_name:ident) {
+    pub trait $trait_name {
+        fn method(&self) -> Method {
+            Method::DefaultMacroCtxt
+        }
+
+        fn $method_name(&self) -> Method {
+            Method::DefaultRootCtxt
+        }
+    }
+
+    impl $trait_name for () {}
+    impl $trait_name for bool {
+        fn method(&self) -> Method {
+            Method::OverrideMacroCtxt
+        }
+
+        fn $method_name(&self) -> Method {
+            Method::OverrideRootCtxt
+        }
+    }
+
+    #[macro_export]
+    macro_rules! $macro_name {
+        (check_resolutions) => {
+            assert_eq!(().method(), Method::DefaultMacroCtxt);
+            assert_eq!($trait_name::method(&()), Method::DefaultMacroCtxt);
+            assert_eq!(().$method_name(), Method::DefaultRootCtxt);
+            assert_eq!($trait_name::$method_name(&()), Method::DefaultRootCtxt);
+
+            assert_eq!(false.method(), Method::OverrideMacroCtxt);
+            assert_eq!($trait_name::method(&false), Method::OverrideMacroCtxt);
+            assert_eq!(false.$method_name(), Method::OverrideRootCtxt);
+            assert_eq!($trait_name::$method_name(&false), Method::OverrideRootCtxt);
+
+            assert_eq!('a'.method(), Method::DefaultMacroCtxt);
+            assert_eq!($trait_name::method(&'a'), Method::DefaultMacroCtxt);
+            assert_eq!('a'.$method_name(), Method::DefaultRootCtxt);
+            assert_eq!($trait_name::$method_name(&'a'), Method::DefaultRootCtxt);
+
+            assert_eq!(1i32.method(), Method::OverrideMacroCtxt);
+            assert_eq!($trait_name::method(&1i32), Method::OverrideMacroCtxt);
+            assert_eq!(1i32.$method_name(), Method::OverrideRootCtxt);
+            assert_eq!($trait_name::$method_name(&1i32), Method::OverrideRootCtxt);
+
+            assert_eq!(1i64.method(), Method::OverrideMacroCtxt);
+            assert_eq!($trait_name::method(&1i64), Method::OverrideMacroCtxt);
+            assert_eq!(1i64.$method_name(), Method::OverrideRootCtxt);
+            assert_eq!($trait_name::$method_name(&1i64), Method::OverrideRootCtxt);
+        };
+        (assert_no_override $v:expr) => {
+            assert_eq!($v.method(), Method::DefaultMacroCtxt);
+            assert_eq!($trait_name::method(&$v), Method::DefaultMacroCtxt);
+            assert_eq!($v.$method_name(), Method::DefaultRootCtxt);
+            assert_eq!($trait_name::$method_name(&$v), Method::DefaultRootCtxt);
+        };
+        (assert_override $v:expr) => {
+            assert_eq!($v.method(), Method::OverrideMacroCtxt);
+            assert_eq!($trait_name::method(&$v), Method::OverrideMacroCtxt);
+            assert_eq!($v.$method_name(), Method::OverrideRootCtxt);
+            assert_eq!($trait_name::$method_name(&$v), Method::OverrideRootCtxt);
+        };
+        (impl for $t:ty) => {
+            impl $trait_name for $t {
+                fn method(&self) -> Method {
+                    Method::OverrideMacroCtxt
+                }
+
+                fn $method_name(&self) -> Method {
+                    Method::OverrideRootCtxt
+                }
+            }
+        };
+    }
+
+    pub macro $macro2_name {
+        (check_resolutions) => {
+            assert_eq!(().method(), Method::DefaultMacroCtxt);
+            assert_eq!($trait_name::method(&()), Method::DefaultMacroCtxt);
+            assert_eq!(().$method_name(), Method::DefaultRootCtxt);
+            assert_eq!($trait_name::$method_name(&()), Method::DefaultRootCtxt);
+
+            assert_eq!(false.method(), Method::OverrideMacroCtxt);
+            assert_eq!($trait_name::method(&false), Method::OverrideMacroCtxt);
+            assert_eq!(false.$method_name(), Method::OverrideRootCtxt);
+            assert_eq!($trait_name::$method_name(&false), Method::OverrideRootCtxt);
+
+            assert_eq!('a'.method(), Method::DefaultMacroCtxt);
+            assert_eq!($trait_name::method(&'a'), Method::DefaultMacroCtxt);
+            assert_eq!('a'.$method_name(), Method::DefaultRootCtxt);
+            assert_eq!($trait_name::$method_name(&'a'), Method::DefaultRootCtxt);
+
+            assert_eq!(1i32.method(), Method::OverrideMacroCtxt);
+            assert_eq!($trait_name::method(&1i32), Method::OverrideMacroCtxt);
+            assert_eq!(1i32.$method_name(), Method::OverrideRootCtxt);
+            assert_eq!($trait_name::$method_name(&1i32), Method::OverrideRootCtxt);
+
+            assert_eq!(1i64.method(), Method::OverrideMacroCtxt);
+            assert_eq!($trait_name::method(&1i64), Method::OverrideMacroCtxt);
+            assert_eq!(1i64.$method_name(), Method::OverrideRootCtxt);
+            assert_eq!($trait_name::$method_name(&1i64), Method::OverrideRootCtxt);
+        },
+        (assert_no_override $v:expr) => {
+            assert_eq!($v.method(), Method::DefaultMacroCtxt);
+            assert_eq!($trait_name::method(&$v), Method::DefaultMacroCtxt);
+            assert_eq!($v.$method_name(), Method::DefaultRootCtxt);
+            assert_eq!($trait_name::$method_name(&$v), Method::DefaultRootCtxt);
+        },
+        (assert_override $v:expr) => {
+            assert_eq!($v.method(), Method::OverrideMacroCtxt);
+            assert_eq!($trait_name::method(&$v), Method::OverrideMacroCtxt);
+            assert_eq!($v.$method_name(), Method::OverrideRootCtxt);
+            assert_eq!($trait_name::$method_name(&$v), Method::OverrideRootCtxt);
+        },
+        (impl for $t:ty) => {
+            impl $trait_name for $t {
+                fn method(&self) -> Method {
+                    Method::OverrideMacroCtxt
+                }
+
+                fn $method_name(&self) -> Method {
+                    Method::OverrideRootCtxt
+                }
+            }
+        }
+    }
+}
+
+x!(test_trait, test_trait2, MyTrait, method);
+
+impl MyTrait for char {}
+test_trait!(impl for i32);
+test_trait2!(impl for i64);
+
+pub fn check_crate_local() {
+    test_trait!(check_resolutions);
+    test_trait2!(check_resolutions);
+}
+
+// Check that any comparison of idents at monomorphization time is correct
+pub fn check_crate_local_generic<T: MyTrait, U: MyTrait>(t: T, u: U) {
+    test_trait!(check_resolutions);
+    test_trait2!(check_resolutions);
+
+    test_trait!(assert_no_override t);
+    test_trait2!(assert_no_override t);
+    test_trait!(assert_override u);
+    test_trait2!(assert_override u);
+}

src/test/ui/hygiene/auxiliary/pub_hygiene.rs

@@ -0,0 +1,7 @@
+#![feature(decl_macro)]
+
+macro x() {
+    pub struct MyStruct;
+}
+
+x!();

src/test/ui/hygiene/auxiliary/use_by_macro.rs

@@ -0,0 +1,15 @@
+#![feature(decl_macro)]
+
+macro x($macro_name:ident) {
+    #[macro_export]
+    macro_rules! $macro_name {
+        (define) => {
+            pub struct MyStruct;
+        };
+        (create) => {
+            MyStruct {}
+        };
+    }
+}
+
+x!(my_struct);

src/test/ui/hygiene/auxiliary/variants.rs

@@ -0,0 +1,36 @@
+#![feature(decl_macro)]
+
+#[rustfmt::skip]
+macro x($macro_name:ident, $macro2_name:ident, $type_name:ident, $variant_name:ident) {
+    #[repr(u8)]
+    pub enum $type_name {
+        Variant = 0,
+        $variant_name = 1,
+    }
+
+    #[macro_export]
+    macro_rules! $macro_name {
+        () => {{
+            assert_eq!($type_name::Variant as u8, 0);
+            assert_eq!($type_name::$variant_name as u8, 1);
+            assert_eq!(<$type_name>::Variant as u8, 0);
+            assert_eq!(<$type_name>::$variant_name as u8, 1);
+        }};
+    }
+
+    pub macro $macro2_name {
+        () => {{
+            assert_eq!($type_name::Variant as u8, 0);
+            assert_eq!($type_name::$variant_name as u8, 1);
+            assert_eq!(<$type_name>::Variant as u8, 0);
+            assert_eq!(<$type_name>::$variant_name as u8, 1);
+        }},
+    }
+}
+
+x!(test_variants, test_variants2, MyEnum, Variant);
+
+pub fn check_variants() {
+    test_variants!();
+    test_variants2!();
+}