#[lang] not feature gated

gcc/rust/checks/errors/feature/rust-feature-gate.cc

@@ -146,6 +146,24 @@ FeatureGate::check_may_dangle_attribute (
     }
 }
 
+void
+FeatureGate::check_lang_item_attribute (
+  const std::vector<AST::Attribute> &attributes)
+{
+  for (const AST::Attribute &attr : attributes)
+    {
+      const auto &str_path = attr.get_path ().as_string ();
+      bool is_lang_item = str_path == Values::Attributes::LANG
+			  && attr.has_attr_input ()
+			  && attr.get_attr_input ().get_attr_input_type ()
+			       == AST::AttrInput::AttrInputType::LITERAL;
+
+      if (is_lang_item)
+	gate (Feature::Name::LANG_ITEMS, attr.get_locus (),
+	      "lang items are subject to change");
+    }
+}
+
 void
 FeatureGate::visit (AST::MacroRulesDefinition &rules_def)
 {
@@ -158,6 +176,8 @@ FeatureGate::visit (AST::Function &function)
   if (!function.is_external ())
     check_rustc_attri (function.get_outer_attrs ());
 
+  check_lang_item_attribute (function.get_outer_attrs ());
+
   AST::DefaultASTVisitor::visit (function);
 }
 
@@ -186,6 +206,7 @@ FeatureGate::visit (AST::Trait &trait)
   if (trait.is_auto ())
     gate (Feature::Name::OPTIN_BUILTIN_TRAITS, trait.get_locus (),
 	  "auto traits are experimental and possibly buggy");
+  check_lang_item_attribute (trait.get_outer_attrs ());
   AST::DefaultASTVisitor::visit (trait);
 }
 
@@ -243,4 +264,32 @@ FeatureGate::visit (AST::UseTreeGlob &use)
   // #[feature(prelude_import)]
 }
 
+void
+FeatureGate::visit (AST::StructStruct &struct_item)
+{
+  check_lang_item_attribute (struct_item.get_outer_attrs ());
+  AST::DefaultASTVisitor::visit (struct_item);
+}
+
+void
+FeatureGate::visit (AST::TraitItemType &trait_item_type)
+{
+  check_lang_item_attribute (trait_item_type.get_outer_attrs ());
+  AST::DefaultASTVisitor::visit (trait_item_type);
+}
+
+void
+FeatureGate::visit (AST::Enum &enum_item)
+{
+  check_lang_item_attribute (enum_item.get_outer_attrs ());
+  AST::DefaultASTVisitor::visit (enum_item);
+}
+
+void
+FeatureGate::visit (AST::EnumItem &enum_variant)
+{
+  check_lang_item_attribute (enum_variant.get_outer_attrs ());
+  AST::DefaultASTVisitor::visit (enum_variant);
+}
+
 } // namespace Rust

gcc/rust/checks/errors/feature/rust-feature-gate.h

@@ -47,12 +47,18 @@ class FeatureGate : public AST::DefaultASTVisitor
   void visit (AST::ExternBlock &block) override;
   void visit (AST::MacroRulesDefinition &rules_def) override;
   void visit (AST::RangePattern &pattern) override;
+  void visit (AST::StructStruct &struct_item) override;
+  void visit (AST::TraitItemType &trait_item_type) override;
+  void visit (AST::Enum &enum_item) override;
+  void visit (AST::EnumItem &enum_variant) override;
 
 private:
   void gate (Feature::Name name, location_t loc, const std::string &error_msg);
   void check_rustc_attri (const std::vector<AST::Attribute> &attributes);
   void
   check_may_dangle_attribute (const std::vector<AST::Attribute> &attributes);
+  void
+  check_lang_item_attribute (const std::vector<AST::Attribute> &attributes);
   std::set<Feature::Name> valid_features;
 };
 } // namespace Rust

gcc/testsuite/rust/borrowck/reference.rs

@@ -1,6 +1,7 @@
 // { dg-additional-options "-frust-compile-until=compilation -frust-borrowcheck -fdiagnostics-show-caret -fdiagnostics-show-line-numbers" }
 // { dg-enable-nn-line-numbers "" }
 
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/borrowck/tmp.rs

@@ -1,6 +1,7 @@
 // { dg-additional-options "-frust-compile-until=compilation -frust-borrowcheck -fdiagnostics-show-caret -fdiagnostics-show-line-numbers" }
 // { dg-enable-nn-line-numbers "" }
 
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/additional-trait-bounds1.rs

@@ -1,4 +1,4 @@
-#![feature(optin_builtin_traits)]
+#![feature(optin_builtin_traits, lang_items)]
 
 pub unsafe auto trait Send {}
 #[lang = "sync"]

gcc/testsuite/rust/compile/additional-trait-bounds2.rs

@@ -1,4 +1,4 @@
-#![feature(optin_builtin_traits)]
+#![feature(optin_builtin_traits, lang_items)]
 
 pub unsafe auto trait Send {}
 #[lang = "sync"]

gcc/testsuite/rust/compile/additional-trait-bounds2nr2.rs

@@ -1,4 +1,4 @@
-#![feature(optin_builtin_traits)]
+#![feature(optin_builtin_traits, lang_items)]
 
 pub unsafe auto trait Send {}
 #[lang = "sync"]

gcc/testsuite/rust/compile/auto_traits1.rs

@@ -1,6 +1,6 @@
 // { dg-additional-options "-frust-compile-until=typecheck" }
 
-#![feature(optin_builtin_traits)]
+#![feature(optin_builtin_traits, lang_items)]
 
 pub unsafe auto trait Send {}
 #[lang = "sync"]

gcc/testsuite/rust/compile/auto_traits2.rs

@@ -1,4 +1,4 @@
-#![feature(optin_builtin_traits)]
+#![feature(optin_builtin_traits, lang_items)]
 
 pub unsafe auto trait Send {}
 #[lang = "sync"]

gcc/testsuite/rust/compile/bad-rpit1.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/black_box.rs

@@ -1,5 +1,5 @@
 // { dg-options "-fdump-tree-gimple" }
-#![feature(rustc_attrs)]
+#![feature(rustc_attrs, lang_items)]
 
 #[lang = "sized"]
 pub trait Sized {}

gcc/testsuite/rust/compile/bounds1.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/box_syntax_feature_gate.rs

@@ -1,4 +1,5 @@
 // { dg-options "-frust-compile-until=lowering" }
+#![feature(lang_items)]
 #[lang = "owned_box"]
 pub struct Box<T>;
 

gcc/testsuite/rust/compile/bug-with-default-generic.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/canonical_paths1.rs

@@ -1,4 +1,5 @@
 // { dg-additional-options "-w -fdump-tree-gimple -frust-crate=example" }
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/cast_generics.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/closure_no_type_anno.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/cmp1.rs

@@ -1,6 +1,7 @@
 // { dg-options "-w" }
 // taken from https://github.com/rust-lang/rust/blob/e1884a8e3c3e813aada8254edfa120e85bf5ffca/library/core/src/cmp.rs#L98
 
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/complex_qualified_path_in_expr.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/const-issue1440.rs

@@ -1,6 +1,7 @@
 // { dg-additional-options "-w" }
 #![feature(intrinsics)]
 
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_1.rs

@@ -3,6 +3,7 @@
 // There are errors about unused generic parameters, but we can't handle that yet.
 // Still, this code is invalid Rust.
 
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_10.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_11.rs

@@ -1,5 +1,5 @@
 // { dg-options "-w" }
-
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_12.rs

@@ -1,5 +1,5 @@
 // { dg-options "-w" }
-
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_13.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_14.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_15.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_16.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_18.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_19.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_3.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_8.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/const_generics_9.rs

@@ -1,5 +1,5 @@
 // { dg-options "-w" }
-
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/derive-debug1.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 trait Sized {}
 

gcc/testsuite/rust/compile/derive-default1.rs

@@ -1,3 +1,5 @@
+#![feature(lang_items)]
+
 #[derive(Default)]
 struct Foo { _a: i32, _b: i64, _c: u8 }
 

gcc/testsuite/rust/compile/derive-eq-invalid.rs

@@ -1,3 +1,5 @@
+#![feature(lang_items)]
+
 mod core {
     mod cmp {
         #[lang = "eq"]

gcc/testsuite/rust/compile/derive-hash1.rs

@@ -1,4 +1,4 @@
-#![feature(intrinsics)]
+#![feature(intrinsics, lang_items)]
 
 #[lang = "sized"]
 trait Sized {}

gcc/testsuite/rust/compile/derive-partialeq1.rs

@@ -1,4 +1,4 @@
-#![feature(intrinsics)]
+#![feature(intrinsics, lang_items)]
 
 #[lang = "sized"]
 trait Sized {}

gcc/testsuite/rust/compile/derive_clone_enum1.rs

@@ -1,3 +1,5 @@
+#![feature(lang_items)]
+
 #[lang = "clone"]
 trait Clone {
     pub fn clone(&self) -> Self;

gcc/testsuite/rust/compile/derive_clone_enum2.rs

@@ -1,3 +1,5 @@
+#![feature(lang_items)]
+
 #[lang = "clone"]
 trait Clone {
     pub fn clone(&self) -> Self;

gcc/testsuite/rust/compile/derive_clone_enum3.rs

@@ -1,3 +1,5 @@
+#![feature(lang_items)]
+
 #[lang = "clone"]
 trait Clone {
     pub fn clone(&self) -> Self;

gcc/testsuite/rust/compile/derive_macro1.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/derive_macro3.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/derive_macro4.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/derive_macro6.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/derive_partial_ord1.rs

@@ -1,6 +1,6 @@
 // { dg-additional-options "-w" }
 
-#![feature(intrinsics)]
+#![feature(intrinsics, lang_items)]
 
 mod core {
     mod option {

gcc/testsuite/rust/compile/expand_macro_qual_path_in_type.rs

@@ -1,5 +1,6 @@
 // this SEGVs in lowering for now
 // { dg-additional-options "-frust-compile-until=nameresolution" }
+#![feature(lang_items)]
 
 macro_rules! forward_ref_binop {
     (impl $imp:ident, $method:ident for $t:ty, $u:ty) => {

gcc/testsuite/rust/compile/expected_type_args2.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/expected_type_args3.rs

@@ -1,3 +1,4 @@
+#![feature(lang_items)]
 #[lang = "sized"]
 pub trait Sized {}
 

gcc/testsuite/rust/compile/extern_generics.rs

@@ -1,4 +1,5 @@
-#[lang="sized"]
+#![feature(lang_items)]
+#[lang = "sized"]
 trait Sized {}
 
 

gcc/testsuite/rust/compile/for-loop1.rs

@@ -1,5 +1,5 @@
 // { dg-output "loop\r*\nloop\r*\n" }
-#![feature(intrinsics)]
+#![feature(intrinsics, lang_items)]
 
 pub use option::Option::{self, None, Some};
 pub use result::Result::{self, Err, Ok};

gcc/testsuite/rust/compile/for-loop2.rs

@@ -1,5 +1,5 @@
 // { dg-output "1\r*\n2\r*\n" }
-#![feature(intrinsics)]
+#![feature(intrinsics, lang_items)]
 
 pub use option::Option::{self, None, Some};
 pub use result::Result::{self, Err, Ok};

gcc/testsuite/rust/compile/format_args_basic_expansion.rs

@@ -1,4 +1,4 @@
-#![feature(rustc_attrs)]
+#![feature(rustc_attrs, lang_items)]
 
 #[rustc_builtin_macro]
 macro_rules! format_args {