gcc/libgo/runtime/chan.goc

// 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.

package runtime
#include "config.h"
#include "channel.h"

#define nil NULL

typedef _Bool bool;
typedef unsigned char byte;
typedef struct __go_channel chan;

/* Do a channel receive with closed status.  */

func chanrecv2(c *chan, val *byte) (received bool) {
	uintptr_t element_size = c == nil ? 0 : c->element_type->__size;
	if (element_size > 8) {
		return __go_receive_big(c, val, 0);
	} else {
		union {
			char b[8];
			uint64_t v;
		} u;

		u.v = __go_receive_small_closed(c, 0, &received);
#ifndef WORDS_BIGENDIAN
		__builtin_memcpy(val, u.b, element_size);
#else
		__builtin_memcpy(val, u.b + 8 - element_size, element_size);
#endif
		return received;
	}
}

/* Do a channel receive with closed status for a select statement.  */

func chanrecv3(c *chan, val *byte) (received bool) {
	uintptr_t element_size = c->element_type->__size;
	if (element_size > 8) {
		return __go_receive_big(c, val, 1);
	} else {
		union {
			char b[8];
			uint64_t v;
		} u;

		u.v = __go_receive_small_closed(c, 1, &received);
#ifndef WORDS_BIGENDIAN
		__builtin_memcpy(val, u.b, element_size);
#else
		__builtin_memcpy(val, u.b + 8 - element_size, element_size);
#endif
		return received;
	}
}