Merge #969

969: Add builtin macros framework r=CohenArthur a=CohenArthur

This PR adds bases to define new builtin macro functions.

Since we operate at the `insert_macro_def` level, this requires builtin macros to be defined, as is the case in the rust standard library:

```rust
    macro_rules! assert {
        ($cond:expr $(,)?) => {{ /* compiler built-in */ }};
        ($cond:expr, $($arg:tt)+) => {{ /* compiler built-in */ }};
    }
```

Co-authored-by: Arthur Cohen <arthur.cohen@embecosm.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/gcc/rust/expand/rust-macro-builtins.h b/gcc/rust/expand/rust-macro-builtins.h
new file mode 100644
index 0000000..f279d39
--- /dev/null
+++ b/gcc/rust/expand/rust-macro-builtins.h
@@ -0,0 +1,34 @@
+// Copyright (C) 2020-2022 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC 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, or (at your option) any later
+// version.
+
+// GCC 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/>.
+
+#ifndef RUST_MACRO_BUILTINS_H
+#define RUST_MACRO_BUILTINS_H
+
+#include "rust-ast.h"
+#include "rust-location.h"
+
+namespace Rust {
+class MacroBuiltin
+{
+public:
+  static AST::ASTFragment assert (Location invoc_locus,
+				  AST::MacroInvocData &invoc);
+};
+} // namespace Rust
+
+#endif // RUST_MACRO_BUILTINS_H