[COMMITTED] gccrs: backend: Expose Bvariable class through rust-gcc header

[Arthur Cohen <arthur.cohen@embecosm.com>]

gcc/rust/ChangeLog:

	* rust-gcc.cc (class Bvariable): Move class to `rust-gcc.h` header.
	* rust-gcc.h: New file.

Tested on x86_64-pc-linux-gnu, committed on master.


Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/rust/rust-gcc.cc | 30 +----------------------
 gcc/rust/rust-gcc.h  | 58 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+), 29 deletions(-)
 create mode 100644 gcc/rust/rust-gcc.h

diff --git a/gcc/rust/rust-gcc.cc b/gcc/rust/rust-gcc.cc
index e3331d60e32..82b2d33977d 100644
--- a/gcc/rust/rust-gcc.cc
+++ b/gcc/rust/rust-gcc.cc
@@ -50,38 +50,10 @@
 #include "rust-linemap.h"
 #include "rust-backend.h"
 #include "rust-object-export.h"
+#include "rust-gcc.h"
 
 #include "backend/rust-tree.h"
 
-// TODO: this will have to be significantly modified to work with Rust
-
-// Bvariable is a bit more complicated, because of zero-sized types.
-// The GNU linker does not permit dynamic variables with zero size.
-// When we see such a variable, we generate a version of the type with
-// non-zero size.  However, when referring to the global variable, we
-// want an expression of zero size; otherwise, if, say, the global
-// variable is passed to a function, we will be passing a
-// non-zero-sized value to a zero-sized value, which can lead to a
-// miscompilation.
-
-class Bvariable
-{
-public:
-  Bvariable (tree t) : t_ (t), orig_type_ (NULL) {}
-
-  Bvariable (tree t, tree orig_type) : t_ (t), orig_type_ (orig_type) {}
-
-  // Get the tree for use as an expression.
-  tree get_tree (Location) const;
-
-  // Get the actual decl;
-  tree get_decl () const { return this->t_; }
-
-private:
-  tree t_;
-  tree orig_type_;
-};
-
 // Get the tree of a variable for use as an expression.  If this is a
 // zero-sized global, create an expression that refers to the decl but
 // has zero size.
diff --git a/gcc/rust/rust-gcc.h b/gcc/rust/rust-gcc.h
new file mode 100644
index 00000000000..085c16d0f3b
--- /dev/null
+++ b/gcc/rust/rust-gcc.h
@@ -0,0 +1,58 @@
+// rust-gcc.cc -- Rust frontend to gcc IR.
+// Copyright (C) 2011-2022 Free Software Foundation, Inc.
+// Contributed by Ian Lance Taylor, Google.
+// forked from gccgo
+
+// 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-system.h"
+
+// This has to be included outside of extern "C", so we have to
+// include it here before tree.h includes it later.
+#include <gmp.h>
+
+#include "tree.h"
+#include "rust-location.h"
+
+// TODO: this will have to be significantly modified to work with Rust
+
+// Bvariable is a bit more complicated, because of zero-sized types.
+// The GNU linker does not permit dynamic variables with zero size.
+// When we see such a variable, we generate a version of the type with
+// non-zero size.  However, when referring to the global variable, we
+// want an expression of zero size; otherwise, if, say, the global
+// variable is passed to a function, we will be passing a
+// non-zero-sized value to a zero-sized value, which can lead to a
+// miscompilation.
+
+class Bvariable
+{
+public:
+  Bvariable (tree t) : t_ (t), orig_type_ (NULL) {}
+
+  Bvariable (tree t, tree orig_type) : t_ (t), orig_type_ (orig_type) {}
+
+  // Get the tree for use as an expression.
+  tree get_tree (Location) const;
+
+  // Get the actual decl;
+  tree get_decl () const { return this->t_; }
+
+private:
+  tree t_;
+  tree orig_type_;
+};
-- 
2.39.1