gcc/libgo/runtime/go-make-slice.c

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/* go-make-slice.c -- make a slice.
Copyright 2011 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 <stdint.h>
#include "runtime.h"
#include "go-alloc.h"
#include "go-assert.h"
#include "go-panic.h"
#include "go-type.h"
#include "array.h"
#include "arch.h"
#include "malloc.h"
/* Dummy word to use as base pointer for make([]T, 0).
Since you cannot take the address of such a slice,
you can't tell that they all have the same base pointer. */
uintptr runtime_zerobase;
struct __go_open_array
__go_make_slice2 (const struct __go_type_descriptor *td, uintptr_t len,
uintptr_t cap)
{
const struct __go_slice_type* std;
intgo ilen;
intgo icap;
uintptr_t size;
struct __go_open_array ret;
__go_assert ((td->__code & GO_CODE_MASK) == GO_SLICE);
std = (const struct __go_slice_type *) td;
ilen = (intgo) len;
if (ilen < 0
|| (uintptr_t) ilen != len
|| (std->__element_type->__size > 0
&& len > MaxMem / std->__element_type->__size))
runtime_panicstring ("makeslice: len out of range");
icap = (intgo) cap;
if (cap < len
|| (uintptr_t) icap != cap
|| (std->__element_type->__size > 0
&& cap > MaxMem / std->__element_type->__size))
runtime_panicstring ("makeslice: cap out of range");
ret.__count = ilen;
ret.__capacity = icap;
size = cap * std->__element_type->__size;
if (size == 0)
ret.__values = &runtime_zerobase;
else if ((std->__element_type->__code & GO_NO_POINTERS) != 0)
ret.__values =
runtime_mallocgc (size,
(uintptr) std->__element_type | TypeInfo_Array,
FlagNoScan);
else
ret.__values =
runtime_mallocgc (size,
(uintptr) std->__element_type | TypeInfo_Array,
0);
return ret;
}
struct __go_open_array
__go_make_slice1 (const struct __go_type_descriptor *td, uintptr_t len)
{
return __go_make_slice2 (td, len, len);
}
struct __go_open_array
__go_make_slice2_big (const struct __go_type_descriptor *td, uint64_t len,
uint64_t cap)
{
uintptr_t slen;
uintptr_t scap;
slen = (uintptr_t) len;
if ((uint64_t) slen != len)
runtime_panicstring ("makeslice: len out of range");
scap = (uintptr_t) cap;
if ((uint64_t) scap != cap)
runtime_panicstring ("makeslice: cap out of range");
return __go_make_slice2 (td, slen, scap);
}
struct __go_open_array
__go_make_slice1_big (const struct __go_type_descriptor *td, uint64_t len)
{
return __go_make_slice2_big (td, len, len);
}