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);