gcc/libgo/runtime/go-assert-interface.c
Ian Lance Taylor 7a9389330e 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
2010-12-03 04:34:57 +00:00

50 lines
1.5 KiB
C

/* go-assert-interface.c -- interface type assertion for Go.
Copyright 2010 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 by the compiler to implement a type assertion from
one interface type to another. This returns the value that should
go in the first field of the result tuple. The result may be an
empty or a non-empty interface. */
const void *
__go_assert_interface (const struct __go_type_descriptor *lhs_descriptor,
const struct __go_type_descriptor *rhs_descriptor)
{
const struct __go_interface_type *lhs_interface;
if (rhs_descriptor == NULL)
{
struct __go_empty_interface panic_arg;
/* A type assertion is not permitted with a nil interface. */
newTypeAssertionError (NULL,
NULL,
lhs_descriptor,
NULL,
NULL,
lhs_descriptor->__reflection,
NULL,
&panic_arg);
__go_panic (panic_arg);
}
/* A type assertion to an empty interface just returns the object
descriptor. */
__go_assert (lhs_descriptor->__code == GO_INTERFACE);
lhs_interface = (const struct __go_interface_type *) lhs_descriptor;
if (lhs_interface->__methods.__count == 0)
return rhs_descriptor;
return __go_convert_interface_2 (lhs_descriptor, rhs_descriptor, 0);
}