1 /* go-make-slice.c -- make a slice.
3 Copyright 2011 The Go Authors. All rights reserved.
4 Use of this source code is governed by a BSD-style
5 license that can be found in the LICENSE file. */
11 #include "go-assert.h"
18 /* Dummy word to use as base pointer for make([]T, 0).
19 Since you cannot take the address of such a slice,
20 you can't tell that they all have the same base pointer. */
21 uintptr runtime_zerobase
;
23 struct __go_open_array
24 __go_make_slice2 (const struct __go_type_descriptor
*td
, uintptr_t len
,
27 const struct __go_slice_type
* std
;
31 struct __go_open_array ret
;
33 __go_assert (td
->__code
== GO_SLICE
);
34 std
= (const struct __go_slice_type
*) td
;
37 if (ilen
< 0 || (uintptr_t) ilen
!= len
)
38 runtime_panicstring ("makeslice: len out of range");
42 || (uintptr_t) icap
!= cap
43 || (std
->__element_type
->__size
> 0
44 && cap
> MaxMem
/ std
->__element_type
->__size
))
45 runtime_panicstring ("makeslice: cap out of range");
48 ret
.__capacity
= icap
;
50 size
= cap
* std
->__element_type
->__size
;
53 ret
.__values
= &runtime_zerobase
;
54 else if ((std
->__element_type
->__code
& GO_NO_POINTERS
) != 0)
55 ret
.__values
= runtime_mallocgc (size
, FlagNoPointers
, 1, 1);
58 ret
.__values
= runtime_mallocgc (size
, 0, 1, 1);
61 runtime_settype (ret
.__values
,
62 (uintptr
) std
->__element_type
| TypeInfo_Array
);
68 struct __go_open_array
69 __go_make_slice1 (const struct __go_type_descriptor
*td
, uintptr_t len
)
71 return __go_make_slice2 (td
, len
, len
);
74 struct __go_open_array
75 __go_make_slice2_big (const struct __go_type_descriptor
*td
, uint64_t len
,
81 slen
= (uintptr_t) len
;
82 if ((uint64_t) slen
!= len
)
83 runtime_panicstring ("makeslice: len out of range");
85 scap
= (uintptr_t) cap
;
86 if ((uint64_t) scap
!= cap
)
87 runtime_panicstring ("makeslice: cap out of range");
89 return __go_make_slice2 (td
, slen
, scap
);
92 struct __go_open_array
93 __go_make_slice1_big (const struct __go_type_descriptor
*td
, uint64_t len
)
95 return __go_make_slice2_big (td
, len
, len
);