gcc/libgo/runtime/go-reflect.c
Ian Lance Taylor 3b8dffe701 Change builtin make to runtime call at lowering time.
Use kindNoPointers as 6g does.

	* Make-lang.in (go/expressions.o): Depend on $(GO_RUNTIME_H).

From-SVN: r175008
2011-06-14 05:53:10 +00:00

193 lines
5.6 KiB
C

/* go-reflect.c -- implement unsafe.Reflect and unsafe.Typeof 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 <stdlib.h>
#include <stdint.h>
#include "interface.h"
#include "go-alloc.h"
#include "go-panic.h"
#include "go-string.h"
#include "go-type.h"
/* For field alignment. */
struct field_align
{
char c;
struct __go_type_descriptor *p;
};
/* The type descriptors in the runtime package. */
extern const struct __go_type_descriptor ptr_bool_descriptor
asm ("__go_td_pN30_libgo_runtime.runtime.BoolType");
extern const struct __go_type_descriptor ptr_float_descriptor
asm ("__go_td_pN31_libgo_runtime.runtime.FloatType");
extern const struct __go_type_descriptor ptr_complex_descriptor
asm ("__go_td_pN33_libgo_runtime.runtime.ComplexType");
extern const struct __go_type_descriptor ptr_int_descriptor
asm ("__go_td_pN29_libgo_runtime.runtime.IntType");
extern const struct __go_type_descriptor ptr_uint_descriptor
asm ("__go_td_pN30_libgo_runtime.runtime.UintType");
extern const struct __go_type_descriptor ptr_string_descriptor
asm ("__go_td_pN32_libgo_runtime.runtime.StringType");
extern const struct __go_type_descriptor ptr_unsafe_pointer_decriptor
asm ("__go_td_pN39_libgo_runtime.runtime.UnsafePointerType");
extern const struct __go_type_descriptor ptr_array_descriptor
asm ("__go_td_pN31_libgo_runtime.runtime.ArrayType");
extern const struct __go_type_descriptor ptr_slice_descriptor
asm ("__go_td_pN31_libgo_runtime.runtime.SliceType");
extern const struct __go_type_descriptor ptr_chan_descriptor
asm ("__go_td_pN30_libgo_runtime.runtime.ChanType");
extern const struct __go_type_descriptor ptr_func_descriptor
asm ("__go_td_pN30_libgo_runtime.runtime.FuncType");
extern const struct __go_type_descriptor ptr_interface_descriptor
asm ("__go_td_pN35_libgo_runtime.runtime.InterfaceType");
extern const struct __go_type_descriptor ptr_map_descriptor
asm ("__go_td_pN29_libgo_runtime.runtime.MapType");
extern const struct __go_type_descriptor ptr_ptr_descriptor
asm ("__go_td_pN29_libgo_runtime.runtime.PtrType");
extern const struct __go_type_descriptor ptr_struct_descriptor
asm ("__go_td_pN32_libgo_runtime.runtime.StructType");
const struct __go_type_descriptor *
get_descriptor (int code)
{
switch (code & GO_CODE_MASK)
{
case GO_BOOL:
return &ptr_bool_descriptor;
case GO_FLOAT32:
case GO_FLOAT64:
return &ptr_float_descriptor;
case GO_COMPLEX64:
case GO_COMPLEX128:
return &ptr_complex_descriptor;
case GO_INT16:
case GO_INT32:
case GO_INT64:
case GO_INT8:
case GO_INT:
return &ptr_int_descriptor;
case GO_UINT16:
case GO_UINT32:
case GO_UINT64:
case GO_UINT8:
case GO_UINTPTR:
case GO_UINT:
return &ptr_uint_descriptor;
case GO_STRING:
return &ptr_string_descriptor;
case GO_UNSAFE_POINTER:
return &ptr_unsafe_pointer_decriptor;
case GO_ARRAY:
return &ptr_array_descriptor;
case GO_SLICE:
return &ptr_slice_descriptor;
case GO_CHAN:
return &ptr_chan_descriptor;
case GO_FUNC:
return &ptr_func_descriptor;
case GO_INTERFACE:
return &ptr_interface_descriptor;
case GO_MAP:
return &ptr_map_descriptor;
case GO_PTR:
return &ptr_ptr_descriptor;
case GO_STRUCT:
return &ptr_struct_descriptor;
default:
abort ();
}
}
/* Implement unsafe.Reflect. */
struct reflect_ret
{
struct __go_empty_interface rettype;
void *addr;
};
struct reflect_ret Reflect (struct __go_empty_interface)
asm ("libgo_unsafe.unsafe.Reflect");
struct reflect_ret
Reflect (struct __go_empty_interface e)
{
struct reflect_ret ret;
if (((uintptr_t) e.__type_descriptor & reflectFlags) != 0)
__go_panic_msg ("invalid interface value");
if (e.__type_descriptor == NULL)
{
ret.rettype.__type_descriptor = NULL;
ret.rettype.__object = NULL;
ret.addr = NULL;
}
else
{
size_t size;
ret.rettype.__type_descriptor =
get_descriptor (e.__type_descriptor->__code);
/* This memcpy is really just an assignment of a const pointer
to a non-const pointer. FIXME: We should canonicalize this
pointer, so that for a given type we always return the same
pointer. */
__builtin_memcpy (&ret.rettype.__object, &e.__type_descriptor,
sizeof (void *));
/* Make a copy of the value. */
size = e.__type_descriptor->__size;
if (size <= sizeof (uint64_t))
ret.addr = __go_alloc (sizeof (uint64_t));
else
ret.addr = __go_alloc (size);
if (__go_is_pointer_type (e.__type_descriptor))
*(void **) ret.addr = e.__object;
else
__builtin_memcpy (ret.addr, e.__object, size);
}
return ret;
}
/* Implement unsafe.Typeof. */
struct __go_empty_interface Typeof (struct __go_empty_interface)
asm ("libgo_unsafe.unsafe.Typeof");
struct __go_empty_interface
Typeof (const struct __go_empty_interface e)
{
struct __go_empty_interface ret;
if (((uintptr_t) e.__type_descriptor & reflectFlags) != 0)
__go_panic_msg ("invalid interface value");
if (e.__type_descriptor == NULL)
{
ret.__type_descriptor = NULL;
ret.__object = NULL;
}
else
{
ret.__type_descriptor = get_descriptor (e.__type_descriptor->__code);
/* This memcpy is really just an assignment of a const pointer
to a non-const pointer. FIXME: We should canonicalize this
pointer, so that for a given type we always return the same
pointer. */
__builtin_memcpy (&ret.__object, &e.__type_descriptor, sizeof (void *));
}
return ret;
}