Add Go frontend, libgo library, and Go testsuite.

gcc/:
	* gcc.c (default_compilers): Add entry for ".go".
	* common.opt: Add -static-libgo as a driver option.
	* doc/install.texi (Configuration): Mention libgo as an option for
	--enable-shared.  Mention go as an option for --enable-languages.
	* doc/invoke.texi (Overall Options): Mention .go as a file name
	suffix.  Mention go as a -x option.
	* doc/frontends.texi (G++ and GCC): Mention Go as a supported
	language.
	* doc/sourcebuild.texi (Top Level): Mention libgo.
	* doc/standards.texi (Standards): Add section on Go language.
	Move references for other languages into their own section.
	* doc/contrib.texi (Contributors): Mention that I contributed the
	Go frontend.
gcc/testsuite/:
	* lib/go.exp: New file.
	* lib/go-dg.exp: New file.
	* lib/go-torture.exp: New file.
	* lib/target-supports.exp (check_compile): Match // Go.

From-SVN: r167407

1 files changed, 138 insertions, 0 deletions

diff --git a/libgo/runtime/go-convert-interface.c b/libgo/runtime/go-convert-interface.c
new file mode 100644
index 0000000..259456c
--- /dev/null
+++ b/libgo/runtime/go-convert-interface.c
@@ -0,0 +1,138 @@
+/* go-convert-interface.c -- convert interfaces for Go.
+
+   Copyright 2009 The Go Authors. All rights reserved.
+   Use of this source code is governed by a BSD-style
+   license that can be found in the LICENSE file.  */
+
+#include "go-alloc.h"
+#include "go-assert.h"
+#include "go-panic.h"
+#include "interface.h"
+
+/* This is called when converting one interface type into another
+   interface type.  LHS_DESCRIPTOR is the type descriptor of the
+   resulting interface.  RHS_DESCRIPTOR is the type descriptor of the
+   object being converted.  This builds and returns a new interface
+   method table.  If any method in the LHS_DESCRIPTOR interface is not
+   implemented by the object, the conversion fails.  If the conversion
+   fails, then if MAY_FAIL is true this returns NULL; otherwise, it
+   panics.  */
+
+void *
+__go_convert_interface_2 (const struct __go_type_descriptor *lhs_descriptor,
+			  const struct __go_type_descriptor *rhs_descriptor,
+			  _Bool may_fail)
+{
+  const struct __go_interface_type *lhs_interface;
+  int lhs_method_count;
+  const struct __go_interface_method* lhs_methods;
+  const void **methods;
+  const struct __go_uncommon_type *rhs_uncommon;
+  int rhs_method_count;
+  const struct __go_method *p_rhs_method;
+  int i;
+
+  if (rhs_descriptor == NULL)
+    {
+      /* A nil value always converts to nil.  */
+      return NULL;
+    }
+
+  __go_assert (lhs_descriptor->__code == GO_INTERFACE);
+  lhs_interface = (const struct __go_interface_type *) lhs_descriptor;
+  lhs_method_count = lhs_interface->__methods.__count;
+  lhs_methods = ((const struct __go_interface_method *)
+		 lhs_interface->__methods.__values);
+
+  /* This should not be called for an empty interface.  */
+  __go_assert (lhs_method_count > 0);
+
+  rhs_uncommon = rhs_descriptor->__uncommon;
+  if (rhs_uncommon == NULL || rhs_uncommon->__methods.__count == 0)
+    {
+      struct __go_empty_interface panic_arg;
+
+      if (may_fail)
+	return NULL;
+
+      newTypeAssertionError (NULL,
+			     rhs_descriptor,
+			     lhs_descriptor,
+			     NULL,
+			     rhs_descriptor->__reflection,
+			     lhs_descriptor->__reflection,
+			     lhs_methods[0].__name,
+			     &panic_arg);
+      __go_panic (panic_arg);
+    }
+
+  rhs_method_count = rhs_uncommon->__methods.__count;
+  p_rhs_method = ((const struct __go_method *)
+		  rhs_uncommon->__methods.__values);
+
+  methods = NULL;
+
+  for (i = 0; i < lhs_method_count; ++i)
+    {
+      const struct __go_interface_method *p_lhs_method;
+
+      p_lhs_method = &lhs_methods[i];
+
+      while (rhs_method_count > 0
+	     && (!__go_ptr_strings_equal (p_lhs_method->__name,
+					  p_rhs_method->__name)
+		 || !__go_ptr_strings_equal (p_lhs_method->__pkg_path,
+					     p_rhs_method->__pkg_path)))
+	{
+	  ++p_rhs_method;
+	  --rhs_method_count;
+	}
+
+      if (rhs_method_count == 0
+	  || !__go_type_descriptors_equal (p_lhs_method->__type,
+					   p_rhs_method->__mtype))
+	{
+	  struct __go_empty_interface panic_arg;
+
+	  if (methods != NULL)
+	    __go_free (methods);
+
+	  if (may_fail)
+	    return NULL;
+
+	  newTypeAssertionError (NULL,
+				 rhs_descriptor,
+				 lhs_descriptor,
+				 NULL,
+				 rhs_descriptor->__reflection,
+				 lhs_descriptor->__reflection,
+				 p_lhs_method->__name,
+				 &panic_arg);
+	  __go_panic (panic_arg);
+	}
+
+      if (methods == NULL)
+	{
+	  methods = (const void **) __go_alloc ((lhs_method_count + 1)
+						* sizeof (void *));
+
+	  /* The first field in the method table is always the type of
+	     the object.  */
+	  methods[0] = rhs_descriptor;
+	}
+
+      methods[i + 1] = p_rhs_method->__function;
+    }
+
+  return methods;
+}
+
+/* This is called by the compiler to convert a value from one
+   interface type to another.  */
+
+void *
+__go_convert_interface (const struct __go_type_descriptor *lhs_descriptor,
+			const struct __go_type_descriptor *rhs_descriptor)
+{
+  return __go_convert_interface_2 (lhs_descriptor, rhs_descriptor, 0);
+}