libgo/runtime/go-setenv.c

   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
  15 /* Set the C environment from Go.  This is called by syscall.Setenv.  */
  16
  17 void setenv_c (String, String) __asm__ (GOSYM_PREFIX "syscall.setenv_c");
  18
  19 void
  20 setenv_c (String k, String v)
  21 {
  22   const byte *ks;
  23   unsigned char *kn;
  24   const byte *vs;
  25   unsigned char *vn;
  26
  27   ks = k.str;
  28   if (ks == NULL)
  29     ks = (const byte *) "";
  30   kn = NULL;
  31
  32   vs = v.str;
  33   if (vs == NULL)
  34     vs = (const byte *) "";
  35   vn = NULL;
  36
  37 #ifdef HAVE_SETENV
  38
  39   if (ks != NULL && ks[k.len] != 0)
  40     {
  41       kn = __go_alloc (k.len + 1);
  42       __builtin_memcpy (kn, ks, k.len);
  43       ks = kn;
  44     }
  45
  46   if (vs != NULL && vs[v.len] != 0)
  47     {
  48       vn = __go_alloc (v.len + 1);
  49       __builtin_memcpy (vn, vs, v.len);
  50       vs = vn;
  51     }
  52
  53   setenv ((const char *) ks, (const char *) vs, 1);
  54
  55 #else /* !defined(HAVE_SETENV) */
  56
  57   kn = __go_alloc (k.len + v.len + 2);
  58   __builtin_memcpy (kn, ks, k.len);
  59   kn[k.len] = '=';
  60   __builtin_memcpy (kn + k.len + 1, vs, v.len);
  61   kn[k.len + v.len + 1] = '\0';
  62   putenv ((char *) kn);
  63
  64 #endif /* !defined(HAVE_SETENV) */
  65
  66   if (kn != NULL)
  67     __go_free (kn);
  68   if (vn != NULL)
  69     __go_free (vn);
  70 }