Start using backend interface separate from gofrontend.

	* go-gcc.cc: New file.
	* Make-lang.in (GO_OBJS): Add go/go-gcc.o.
	(go/go-gcc.o): New target.
	(go/go.o): Depend on go/gofrontend/backend.h.
	(go/statements.o): Likewise.

From-SVN: r171917

1 files changed, 199 insertions, 0 deletions

diff --git a/gcc/go/go-gcc.cc b/gcc/go/go-gcc.cc
new file mode 100644
index 0000000..ca2d63b
--- /dev/null
+++ b/gcc/go/go-gcc.cc
@@ -0,0 +1,199 @@
+// go-gcc.cc -- Go frontend to gcc IR.
+// Copyright (C) 2011 Free Software Foundation, Inc.
+// Contributed by Ian Lance Taylor, Google.
+
+// 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 "go-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>
+
+#ifndef ENABLE_BUILD_WITH_CXX
+extern "C"
+{
+#endif
+
+#include "tree.h"
+
+#ifndef ENABLE_BUILD_WITH_CXX
+}
+#endif
+
+#include "backend.h"
+
+// A class wrapping a tree.
+
+class Gcc_tree
+{
+ public:
+  Gcc_tree(tree t)
+    : t_(t)
+  { }
+
+  tree
+  get_tree()
+  { return this->t_; }
+
+ private:
+  tree t_;
+};
+
+// In gcc, types, expressions, and statements are all trees.
+class Btype : public Gcc_tree
+{
+ public:
+  Btype(tree t)
+    : Gcc_tree(t)
+  { }
+};
+
+class Bexpression : public Gcc_tree
+{
+ public:
+  Bexpression(tree t)
+    : Gcc_tree(t)
+  { }
+};
+
+class Bstatement : public Gcc_tree
+{
+ public:
+  Bstatement(tree t)
+    : Gcc_tree(t)
+  { }
+};
+
+// This file implements the interface between the Go frontend proper
+// and the gcc IR.  This implements specific instantiations of
+// abstract classes defined by the Go frontend proper.  The Go
+// frontend proper class methods of these classes to generate the
+// backend representation.
+
+class Gcc_backend : public Backend
+{
+ public:
+  // Types.
+
+  Btype*
+  error_type()
+  { gcc_unreachable(); }
+
+  Btype*
+  void_type()
+  { gcc_unreachable(); }
+
+  Btype*
+  bool_type()
+  { gcc_unreachable(); }
+
+  Btype*
+  integer_type(bool /* is_unsigned */, int /* bits */)
+  { gcc_unreachable(); }
+
+  Btype*
+  float_type(int /* bits */)
+  { gcc_unreachable(); }
+
+  Btype*
+  string_type()
+  { gcc_unreachable(); }
+
+  Btype*
+  function_type(const Function_type*, Btype* /* receiver */,
+		const Btypes* /* parameters */,
+		const Btypes* /* results */)
+  { gcc_unreachable(); }
+
+  Btype*
+  struct_type(const Struct_type*, const Btypes* /* field_types */)
+  { gcc_unreachable(); }
+
+  Btype*
+  array_type(const Btype* /* element_type */, const Bexpression* /* length */)
+  { gcc_unreachable(); }
+
+  Btype*
+  slice_type(const Btype* /* element_type */)
+  { gcc_unreachable(); }
+
+  Btype*
+  map_type(const Btype* /* key_type */, const Btype* /* value_type */,
+	   source_location)
+  { gcc_unreachable(); }
+
+  Btype*
+  channel_type(const Btype* /* element_type */)
+  { gcc_unreachable(); }
+
+  Btype*
+  interface_type(const Interface_type*, const Btypes* /* method_types */)
+  { gcc_unreachable(); }
+
+  // Statements.
+
+  // Create an assignment statement.
+  Bstatement*
+  assignment(Bexpression* lhs, Bexpression* rhs,
+	     source_location location);
+
+ private:
+  // Make a Bstatement from a tree.
+  Bstatement*
+  make_statement(tree t)
+  { return new Bstatement(t); }
+};
+
+// Assignment.
+
+Bstatement*
+Gcc_backend::assignment(Bexpression* lhs, Bexpression* rhs,
+			source_location location)
+{
+  return this->make_statement(fold_build2_loc(location, MODIFY_EXPR,
+					      void_type_node,
+					      lhs->get_tree(),
+					      rhs->get_tree()));
+}
+
+// The single backend.
+
+static Gcc_backend gcc_backend;
+
+// Return the backend generator.
+
+Backend*
+go_get_backend()
+{
+  return &gcc_backend;
+}
+
+// FIXME: Temporary functions while converting to the new backend
+// interface.
+
+Bexpression*
+tree_to_expr(tree t)
+{
+  return new Bexpression(t);
+}
+
+tree
+statement_to_tree(Bstatement* bs)
+{
+  return bs->get_tree();
+}