[gcc r13-4652] gccrs: Add Rust ABI enum helpers

[gcc r13-4652] gccrs: Add Rust ABI enum helpers

[Arthur Cohen]

https://gcc.gnu.org/g:15b0278905ed80413867ad78868a597dd7227170

commit r13-4652-g15b0278905ed80413867ad78868a597dd7227170
Author: Philip Herron <philip.herron@embecosm.com>
Date:   Tue Aug 23 16:23:22 2022 +0100

    gccrs: Add Rust ABI enum helpers
    
    This is a simple helper over an enum of possible ABI options in Rust.
    
            gcc/rust/
            * util/rust-abi.cc: New.
            * util/rust-abi.h: New.

Diff:
---
 gcc/rust/util/rust-abi.cc | 72 +++++++++++++++++++++++++++++++++++++++++++++++
 gcc/rust/util/rust-abi.h  | 45 +++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+)

diff --git a/gcc/rust/util/rust-abi.cc b/gcc/rust/util/rust-abi.cc
new file mode 100644
index 00000000000..6477c3790af
--- /dev/null
+++ b/gcc/rust/util/rust-abi.cc
@@ -0,0 +1,72 @@
+// 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/>.
+
+#include "rust-abi.h"
+
+namespace Rust {
+
+Rust::ABI
+get_abi_from_string (const std::string &abi)
+{
+  if (abi.compare ("rust") == 0)
+    return Rust::ABI::RUST;
+  else if (abi.compare ("rust-intrinsic") == 0)
+    return Rust::ABI::INTRINSIC;
+  else if (abi.compare ("C") == 0)
+    return Rust::ABI::C;
+  else if (abi.compare ("cdecl") == 0)
+    return Rust::ABI::CDECL;
+  else if (abi.compare ("stdcall") == 0)
+    return Rust::ABI::STDCALL;
+  else if (abi.compare ("fastcall") == 0)
+    return Rust::ABI::FASTCALL;
+  else if (abi.compare ("sysv64") == 0)
+    return Rust::ABI::SYSV64;
+  else if (abi.compare ("win64") == 0)
+    return Rust::ABI::WIN64;
+
+  return Rust::ABI::UNKNOWN;
+}
+
+std::string
+get_string_from_abi (Rust::ABI abi)
+{
+  switch (abi)
+    {
+    case Rust::ABI::RUST:
+      return "rust";
+    case Rust::ABI::INTRINSIC:
+      return "rust-intrinsic";
+    case Rust::ABI::C:
+      return "C";
+    case Rust::ABI::CDECL:
+      return "cdecl";
+    case Rust::ABI::STDCALL:
+      return "stdcall";
+    case Rust::ABI::FASTCALL:
+      return "fastcall";
+    case Rust::ABI::SYSV64:
+      return "sysv64";
+    case Rust::ABI::WIN64:
+      return "win64";
+
+    case Rust::ABI::UNKNOWN:
+      return "unknown";
+    }
+  return "unknown";
+}
+
+} // namespace Rust
diff --git a/gcc/rust/util/rust-abi.h b/gcc/rust/util/rust-abi.h
new file mode 100644
index 00000000000..d794cc35fb3
--- /dev/null
+++ b/gcc/rust/util/rust-abi.h
@@ -0,0 +1,45 @@
+// 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_ABI_OPTIONS_H
+#define RUST_ABI_OPTIONS_H
+
+#include "rust-system.h"
+
+namespace Rust {
+
+enum ABI
+{
+  UNKNOWN,
+  RUST,
+  INTRINSIC,
+  C,
+  CDECL,
+  STDCALL,
+  FASTCALL,
+  WIN64,
+  SYSV64
+};
+
+extern Rust::ABI
+get_abi_from_string (const std::string &abi);
+
+extern std::string
+get_string_from_abi (Rust::ABI abi);
+
+} // namespace Rust
+
+#endif // RUST_ABI_OPTIONS_H