3 files changed, 35 insertions, 0 deletions
diff --git a/gcc/rust/expand/rust-macro-builtins.cc b/gcc/rust/expand/rust-macro-builtins.cc
index 8104c57..a4e9854 100644
--- a/gcc/rust/expand/rust-macro-builtins.cc
+++ b/gcc/rust/expand/rust-macro-builtins.cc
@@ -105,6 +105,22 @@ std::unordered_map<
     {"test_case", MacroBuiltin::sorry},
     {"global_allocator", MacroBuiltin::sorry},
     {"cfg_accessible", MacroBuiltin::sorry},
+    /* Derive builtins do not need a real transcriber, but still need one. It
+       will however never be called since builtin derive macros get expanded
+       differently, and benefit from knowing on what kind of items they are
+       applied (struct, enums, unions) rather than receiving a list of tokens
+       like regular builtin macros */
+    {"RustcEncodable", MacroBuiltin::proc_macro_builtin},
+    {"RustcDecodable", MacroBuiltin::proc_macro_builtin},
+    {"Clone", MacroBuiltin::proc_macro_builtin},
+    {"Copy", MacroBuiltin::proc_macro_builtin},
+    {"Debug", MacroBuiltin::proc_macro_builtin},
+    {"Default", MacroBuiltin::proc_macro_builtin},
+    {"Eq", MacroBuiltin::proc_macro_builtin},
+    {"PartialEq", MacroBuiltin::proc_macro_builtin},
+    {"Ord", MacroBuiltin::proc_macro_builtin},
+    {"PartialOrd", MacroBuiltin::proc_macro_builtin},
+    {"Hash", MacroBuiltin::proc_macro_builtin},
 };
 
 // FIXME: This should return an Optional
@@ -932,4 +948,11 @@ MacroBuiltin::sorry (Location invoc_locus, AST::MacroInvocData &invoc)
   return AST::Fragment::create_error ();
 }
 
+AST::Fragment
+MacroBuiltin::proc_macro_builtin (Location, AST::MacroInvocData &)
+{
+  // nothing to do!
+  return AST::Fragment::create_error ();
+}
+
 } // namespace Rust
diff --git a/gcc/rust/expand/rust-macro-builtins.h b/gcc/rust/expand/rust-macro-builtins.h
index cf70e49..3759f62 100644
--- a/gcc/rust/expand/rust-macro-builtins.h
+++ b/gcc/rust/expand/rust-macro-builtins.h
@@ -159,6 +159,10 @@ public:
 				     AST::MacroInvocData &invoc);
 
   static AST::Fragment sorry (Location invoc_locus, AST::MacroInvocData &invoc);
+
+  /* Builtin procedural macros do not work directly on tokens, but still need an
+   * empty builtin transcriber to be considered proper builtin macros */
+  static AST::Fragment proc_macro_builtin (Location, AST::MacroInvocData &);
 };
 } // namespace Rust
 
diff --git a/gcc/testsuite/rust/compile/derive_macro7.rs b/gcc/testsuite/rust/compile/derive_macro7.rs
new file mode 100644
index 0000000..108e3cf
--- /dev/null
+++ b/gcc/testsuite/rust/compile/derive_macro7.rs
@@ -0,0 +1,8 @@
+#![feature(rustc_attrs)]
+
+#[rustc_builtin_macro]
+#[stable(feature = "rust1", since = "1.0.0")]
+#[allow_internal_unstable(core_intrinsics, libstd_sys_internals)]
+pub macro RustcDecodable($item:item) {
+    /* compiler built-in */
+}
+\ No newline at end of file