gcc/rust/ChangeLog:

	* ast/rust-ast-visitor.cc (DefaultASTVisitor::visit):
	enabled a default visitor to be overrided
	* ast/rust-ast-visitor.h:
	passes a method virtual
	* checks/errors/rust-feature-gate.cc (FeatureGate::visit):
	implements all checks for the new features
	* checks/errors/rust-feature-gate.h:
	the prototypes of the new checkers
	* checks/errors/rust-feature.cc (Feature::create):
	implements the recognition and creation of some new features
	* checks/errors/rust-feature.h:
	creation of the features name in the enum

gcc/testsuite/ChangeLog:

	* rust/compile/feature_extern_types.rs: Move to...
	* rust/compile/features/extern_types.rs: ...here.
	* rust/compile/feature_intrinsics.rs: Move to...
	* rust/compile/features/intrinsics.rs: ...here.
	* rust/compile/features/arbitrary_self_types_activated.rs: New test.
	* rust/compile/features/arbitrary_self_types_not_activated.rs: New test.
	* rust/compile/features/associated_type_defaults_activated.rs: New test.
	* rust/compile/features/const_trait_impl_activated.rs: New test.
	* rust/compile/features/doc_cfg_activated.rs: New test.
	* rust/compile/features/doc_cfg_not_activated.rs: New test.
	* rust/compile/features/feature.exp: New test.
	* rust/compile/features/impl_trait_in_assoc_type_activated.rs: New test.
	* rust/compile/features/impl_trait_in_assoc_type_not_activated.rs: New test.
	* rust/compile/features/register_tool_activated.rs: New test.
	* rust/compile/features/register_tool_not_activated.rs: New test.

gcc/rust/ast/rust-ast-visitor.cc

@@ -831,8 +831,6 @@ DefaultASTVisitor::visit (AST::Function &function)
   visit (function.get_qualifiers ());
   for (auto &generic : function.get_generic_params ())
     visit (generic);
-  if (function.has_self_param ())
-    visit (function.get_self_param ());
   for (auto &param : function.get_function_params ())
     visit (param);
   if (function.has_return_type ())

gcc/rust/ast/rust-ast-visitor.h

@@ -435,7 +435,7 @@ class DefaultASTVisitor : public ASTVisitor
   virtual void visit (AST::StructPatternElements &spe);
   virtual void visit (AST::MaybeNamedParam &param);
 
-  void visit (AST::Attribute &attribute) {}
+  virtual void visit (AST::Attribute &attribute) {}
 
   template <typename T> void visit_outer_attrs (T &node)
   {

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

@@ -17,11 +17,19 @@
 // <http://www.gnu.org/licenses/>.
 
 #include "rust-feature-gate.h"
+#include "config.h"
+#include "is-a.h"
 #include "rust-abi.h"
+#include "rust-ast.h"
 #include "rust-attribute-values.h"
 #include "rust-ast-visitor.h"
 #include "rust-feature.h"
 #include "rust-ast-full.h"
+#include "rust-item.h"
+#include "rust-path.h"
+#include "rust-type.h"
+#include "rust-tyty.h"
+#include <iostream>
 
 namespace Rust {
 
@@ -236,4 +244,46 @@ FeatureGate::visit (AST::UseTreeGlob &use)
   // #[feature(prelude_import)]
 }
 
+void
+FeatureGate::visit (AST::RawPointerType &type)
+{
+  auto &t = static_cast<AST::TypePath &> (type.get_type_pointed_to ());
+  if (t.get_num_segments () == 1)
+    {
+      auto seg
+	= static_cast<AST::TypePathSegment> (*t.get_segments ().at (0).get ());
+      if (seg.is_big_self_seg ())
+	gate (Feature::Name::ARBITRARY_SELF_TYPES, type.get_locus (),
+	      "arbitrary self types are experimental");
+    }
+}
+
+void
+FeatureGate::visit (AST::ImplTraitType &type)
+{
+  gate (Feature::Name::IMPL_TRAIT_IN_ASSOC_TYPE, type.get_locus (),
+	"impl trait in assoc type is experimental");
+}
+
+void
+FeatureGate::visit (AST::ImplTraitTypeOneBound &type)
+{
+  gate (Feature::Name::IMPL_TRAIT_IN_ASSOC_TYPE, type.get_locus (),
+	"impl trait in assoc type is experimental");
+}
+
+void
+FeatureGate::visit (AST::Attribute &attr)
+{
+  if (attr.get_path().as_string() == "register_tool")
+    gate (Feature::Name::REGISTER_TOOL, attr.get_locus (),
+	  "register tool is an experimental feature");
+}
+
+void
+FeatureGate::visit (AST::TypeAlias &type)
+{
+
+}
+
 } // namespace Rust

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

@@ -20,7 +20,11 @@
 #define RUST_FEATURE_GATE_H
 
 #include "rust-ast-visitor.h"
+#include "rust-ast.h"
 #include "rust-feature.h"
+#include "rust-item.h"
+#include "rust-path.h"
+#include "rust-type.h"
 
 namespace Rust {
 
@@ -47,6 +51,11 @@ 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::RawPointerType &type) override;
+  void visit (AST::ImplTraitType &type) override;
+  void visit (AST::ImplTraitTypeOneBound &type) override;
+  void visit (AST::Attribute &attr) override;
+  void visit (AST::TypeAlias &attr) override;
 
 private:
   void gate (Feature::Name name, location_t loc, const std::string &error_msg);

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

@@ -58,6 +58,18 @@ Feature::create (Feature::Name f)
     case Feature::Name::AUTO_TRAITS:
       return Feature (f, Feature::State::ACTIVE, "optin_builtin_traits",
 		      "1.0.0", 13231);
+    case Feature::Name::ARBITRARY_SELF_TYPES:
+      return Feature (f, Feature::State::ACCEPTED, "arbitrary_self_types", "1.49.0", 44874);
+    case Feature::Name::DOC_CFG:
+      return Feature (f, Feature::State::ACCEPTED, "doc_cfg", "1.49.0", 43781);
+    case Feature::Name::IMPL_TRAIT_IN_ASSOC_TYPE:
+      return Feature (f, Feature::State::ACCEPTED, "impl_trait_in_assoc_type", "1.49.0", 63063);
+    case Feature::Name::REGISTER_TOOL:
+      return Feature (f, Feature::State::ACCEPTED, "register_tool", "1.49.0", 66079);
+    case Feature::Name::ASSOCIATED_TYPE_DEFAULTS:
+      return Feature (f, Feature::State::ACCEPTED, "associated_type_defaults", "1.49.0", 29661);
+    case Feature::Name::CONST_TRAIT_IMPL:
+      return Feature (f, Feature::State::ACCEPTED, "const_trait_impl", "1.49.0", 67792);
     default:
       rust_unreachable ();
     }
@@ -80,6 +92,13 @@ const std::map<std::string, Feature::Name> Feature::name_hash_map = {
   {"raw_ref_op", Feature::Name::RAW_REF_OP},
   {"exclusive_range_pattern", Feature::Name::EXCLUSIVE_RANGE_PATTERN},
   {"prelude_import", Feature::Name::PRELUDE_IMPORT},
+  // Required features for Rust for Linux
+  {"arbitrary_self_types", Feature::Name::ARBITRARY_SELF_TYPES},
+  {"doc_cfg", Feature::Name::DOC_CFG},
+  {"impl_trait_in_assoc_type", Feature::Name::IMPL_TRAIT_IN_ASSOC_TYPE},
+  {"register_tool", Feature::Name::REGISTER_TOOL},
+  {"associated_type_defaults", Feature::Name::ASSOCIATED_TYPE_DEFAULTS},
+  {"const_trait_impl", Feature::Name::CONST_TRAIT_IMPL},
 }; // namespace Rust
 
 tl::optional<Feature::Name>

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

@@ -51,6 +51,12 @@ class Feature
     RAW_REF_OP,
     EXCLUSIVE_RANGE_PATTERN,
     PRELUDE_IMPORT,
+    ARBITRARY_SELF_TYPES,
+    DOC_CFG,
+    IMPL_TRAIT_IN_ASSOC_TYPE,
+    REGISTER_TOOL,
+    ASSOCIATED_TYPE_DEFAULTS,
+    CONST_TRAIT_IMPL,
   };
 
   const std::string &as_string () { return m_name_str; }

gcc/testsuite/rust/compile/features/arbitrary_self_types_activated.rs

@@ -0,0 +1,5 @@
+#![feature(arbitrary_self_types)]
+
+trait Foo {
+    fn bar(self: *const Self);
+}

gcc/testsuite/rust/compile/features/arbitrary_self_types_not_activated.rs

@@ -0,0 +1,3 @@
+trait Foo {
+    fn bar(self: *const Self); // { dg-error "arbitrary self types are experimental." }
+}

gcc/testsuite/rust/compile/features/associated_type_defaults_activated.rs

@@ -0,0 +1 @@
+#![feature(associated_type_defaults)]

gcc/testsuite/rust/compile/features/const_trait_impl_activated.rs

@@ -0,0 +1 @@
+#![feature(const_trait_impl)]

gcc/testsuite/rust/compile/features/doc_cfg_activated.rs

@@ -0,0 +1,20 @@
+#![feature(doc_cfg)]
+
+#[cfg(any(windows, doc))]
+#[doc(cfg(windows))]
+/// The application's icon in the notification area (a.k.a. system tray).
+///
+/// # Examples
+///
+/// ```no_run
+/// extern crate my_awesome_ui_library;
+/// use my_awesome_ui_library::current_app;
+/// use my_awesome_ui_library::windows::notification;
+///
+/// let icon = current_app().get::<notification::Icon>();
+/// icon.show();
+/// icon.show_message("Hello");
+/// ```
+pub struct Icon {
+    // ...
+}

gcc/testsuite/rust/compile/features/doc_cfg_not_activated.rs

@@ -0,0 +1,18 @@
+#[cfg(any(windows, doc))]
+#[doc(cfg(windows))]
+/// The application's icon in the notification area (a.k.a. system tray).
+///
+/// # Examples
+///
+/// ```no_run
+/// extern crate my_awesome_ui_library;
+/// use my_awesome_ui_library::current_app;
+/// use my_awesome_ui_library::windows::notification;
+///
+/// let icon = current_app().get::<notification::Icon>();
+/// icon.show();
+/// icon.show_message("Hello");
+/// ```
+pub struct Icon {
+    // ...
+}

gcc/testsuite/rust/compile/features/feature.exp

@@ -0,0 +1,35 @@
+# Copyright (C) 2021-2024 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# Compile tests, no torture testing.
+#
+# These tests raise errors in the front end; torture testing doesn't apply.
+
+# Load support procs.
+load_lib rust-dg.exp
+
+# Initialize `dg'.
+dg-init
+
+# Main loop.
+set saved-dg-do-what-default ${dg-do-what-default}
+
+set dg-do-what-default "compile"
+dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.rs]] "" ""
+set dg-do-what-default ${saved-dg-do-what-default}
+
+# All done.
+dg-finish

gcc/testsuite/rust/compile/features/impl_trait_in_assoc_type_activated.rs

@@ -0,0 +1,28 @@
+// check-pass
+// { dg-additional-options "-frust-compile-until=lowering" }
+
+#![feature(impl_trait_in_assoc_type)]
+
+fn main() {}
+
+trait Bar {
+    type Assoc;
+}
+
+trait Thing {
+    type Out;
+    fn func() -> Self::Out;
+}
+
+struct AssocIsCopy;
+impl Bar for AssocIsCopy {
+    type Assoc = u8;
+}
+
+impl Thing for AssocIsCopy {
+    type Out = impl Bar<Assoc: Copy>;
+
+    fn func() -> Self::Out {
+        AssocIsCopy
+    }
+}

gcc/testsuite/rust/compile/features/impl_trait_in_assoc_type_not_activated.rs

@@ -0,0 +1,25 @@
+// { dg-additional-options "-frust-compile-until=lowering" }
+
+fn main() {}
+
+trait Bar {
+    type Assoc;
+}
+
+trait Thing {
+    type Out;
+    fn func() -> Self::Out;
+}
+
+struct AssocIsCopy;
+impl Bar for AssocIsCopy {
+    type Assoc = u8;
+}
+
+impl Thing for AssocIsCopy {
+    type Out = impl Bar<Assoc: Copy>; // { dg-error "impl trait in assoc type is experimental" }
+
+    fn func() -> Self::Out {
+        AssocIsCopy
+    }
+}

gcc/testsuite/rust/compile/features/register_tool_activated.rs

@@ -0,0 +1,4 @@
+#![feature(register_tool)]
+#![register_tool(my_tool)]
+
+fn main() {}

gcc/testsuite/rust/compile/features/register_tool_not_activated.rs

@@ -0,0 +1,3 @@
+#![register_tool(my_tool)] // { dg-error "register tool is an experimental feature" }
+
+fn main() {}