gcc/libgo/runtime/iface.goc

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// 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 "go-type.h"
#include "interface.h"
#define nil NULL
typedef _Bool bool;
typedef struct __go_type_descriptor descriptor;
typedef const struct __go_type_descriptor const_descriptor;
typedef struct __go_interface interface;
typedef struct __go_empty_interface empty_interface;
// Compare two type descriptors.
func ifacetypeeq(a *descriptor, b *descriptor) (eq bool) {
eq = __go_type_descriptors_equal(a, b);
}
// Return the descriptor for an empty interface type.n
func efacetype(e empty_interface) (d *const_descriptor) {
return e.__type_descriptor;
}
// Return the descriptor for a non-empty interface type.
func ifacetype(i interface) (d *const_descriptor) {
if (i.__methods == nil) {
return nil;
}
d = i.__methods[0];
}
// Convert an empty interface to an empty interface.
func ifaceE2E2(e empty_interface) (ret empty_interface, ok bool) {
ret = e;
ok = ret.__type_descriptor != nil;
}
// Convert a non-empty interface to an empty interface.
func ifaceI2E2(i interface) (ret empty_interface, ok bool) {
if (i.__methods == nil) {
ret.__type_descriptor = nil;
ret.__object = nil;
ok = 0;
} else {
ret.__type_descriptor = i.__methods[0];
ret.__object = i.__object;
ok = 1;
}
}
// Convert an empty interface to a non-empty interface.
func ifaceE2I2(inter *descriptor, e empty_interface) (ret interface, ok bool) {
if (e.__type_descriptor == nil) {
ret.__methods = nil;
ret.__object = nil;
ok = 0;
} else {
ret.__methods = __go_convert_interface_2(inter,
e.__type_descriptor,
1);
ret.__object = e.__object;
ok = ret.__methods != nil;
}
}
// Convert a non-empty interface to a non-empty interface.
func ifaceI2I2(inter *descriptor, i interface) (ret interface, ok bool) {
if (i.__methods == nil) {
ret.__methods = nil;
ret.__object = nil;
ok = 0;
} else {
ret.__methods = __go_convert_interface_2(inter,
i.__methods[0], 1);
ret.__object = i.__object;
ok = ret.__methods != nil;
}
}
// Convert an empty interface to a pointer type.
func ifaceE2T2P(inter *descriptor, e empty_interface) (ret *void, ok bool) {
if (!__go_type_descriptors_equal(inter, e.__type_descriptor)) {
ret = nil;
ok = 0;
} else {
ret = e.__object;
ok = 1;
}
}
// Convert a non-empty interface to a pointer type.
func ifaceI2T2P(inter *descriptor, i interface) (ret *void, ok bool) {
if (i.__methods == nil
|| !__go_type_descriptors_equal(inter, i.__methods[0])) {
ret = nil;
ok = 0;
} else {
ret = i.__object;
ok = 1;
}
}
// Convert an empty interface to a non-pointer type.
func ifaceE2T2(inter *descriptor, e empty_interface, ret *void) (ok bool) {
if (!__go_type_descriptors_equal(inter, e.__type_descriptor)) {
__builtin_memset(ret, 0, inter->__size);
ok = 0;
} else {
__builtin_memcpy(ret, e.__object, inter->__size);
ok = 1;
}
}
// Convert a non-empty interface to a non-pointer type.
func ifaceI2T2(inter *descriptor, i interface, ret *void) (ok bool) {
if (i.__methods == nil
|| !__go_type_descriptors_equal(inter, i.__methods[0])) {
__builtin_memset(ret, 0, inter->__size);
ok = 0;
} else {
__builtin_memcpy(ret, i.__object, inter->__size);
ok = 1;
}
}
// Return whether we can convert an interface to a type.
func ifaceI2Tp(to *descriptor, from *descriptor) (ok bool) {
ok = __go_can_convert_to_interface(to, from);
}