1 /* go-setenv.c -- set the C environment from Go.
2
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. */
6
7 #include "config.h"
8
9 #include <stddef.h>
10 #include <stdlib.h>
11
12 #include "go-alloc.h"
13 #include "runtime.h"
14 #include "arch.h"
15 #include "malloc.h"
16
17 /* Set the C environment from Go. This is called by syscall.Setenv. */
18
19 void setenv_c (String, String) __asm__ (GOSYM_PREFIX "syscall.setenv_c");
20
21 void
setenv_c(String k,String v)22 setenv_c (String k, String v)
23 {
24 const byte *ks;
25 unsigned char *kn;
26 const byte *vs;
27 unsigned char *vn;
28 intgo len;
29
30 ks = k.str;
31 if (ks == NULL)
32 ks = (const byte *) "";
33 kn = NULL;
34
35 vs = v.str;
36 if (vs == NULL)
37 vs = (const byte *) "";
38 vn = NULL;
39
40 #ifdef HAVE_SETENV
41
42 if (ks != NULL && ks[k.len] != 0)
43 {
44 // Objects that are explicitly freed must be at least 16 bytes in size,
45 // so that they are not allocated using tiny alloc.
46 len = k.len + 1;
47 if (len < TinySize)
48 len = TinySize;
49 kn = __go_alloc (len);
50 __builtin_memcpy (kn, ks, k.len);
51 ks = kn;
52 }
53
54 if (vs != NULL && vs[v.len] != 0)
55 {
56 len = v.len + 1;
57 if (len < TinySize)
58 len = TinySize;
59 vn = __go_alloc (len);
60 __builtin_memcpy (vn, vs, v.len);
61 vs = vn;
62 }
63
64 setenv ((const char *) ks, (const char *) vs, 1);
65
66 #else /* !defined(HAVE_SETENV) */
67
68 len = k.len + v.len + 2;
69 if (len < TinySize)
70 len = TinySize;
71 kn = __go_alloc (len);
72 __builtin_memcpy (kn, ks, k.len);
73 kn[k.len] = '=';
74 __builtin_memcpy (kn + k.len + 1, vs, v.len);
75 kn[k.len + v.len + 1] = '\0';
76 putenv ((char *) kn);
77
78 #endif /* !defined(HAVE_SETENV) */
79
80 if (kn != NULL)
81 __go_free (kn);
82 if (vn != NULL)
83 __go_free (vn);
84 }
85