github.com/guyezi/gofrontend@v0.0.0-20200228202240-7a62a49e62c0/libgo/runtime/go-setenv.c (about)

     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 "runtime.h"
    13  
    14  /* Set the C environment from Go.  This is called by syscall.Setenv.  */
    15  
    16  void setenv_c (String, String) __asm__ (GOSYM_PREFIX "syscall.setenv_c");
    17  
    18  void
    19  setenv_c (String k, String v)
    20  {
    21    const byte *ks;
    22    unsigned char *kn;
    23    const byte *vs;
    24    unsigned char *vn;
    25  
    26    ks = k.str;
    27    if (ks == NULL)
    28      ks = (const byte *) "";
    29    kn = NULL;
    30  
    31    vs = v.str;
    32    if (vs == NULL)
    33      vs = (const byte *) "";
    34    vn = NULL;
    35  
    36  #ifdef HAVE_SETENV
    37  
    38    if (ks[k.len] != 0)
    39      {
    40        kn = malloc (k.len + 1);
    41        if (kn == NULL)
    42  	runtime_throw ("out of malloc memory");
    43        __builtin_memcpy (kn, ks, k.len);
    44        kn[k.len] = '\0';
    45        ks = kn;
    46      }
    47  
    48    if (vs[v.len] != 0)
    49      {
    50        vn = malloc (v.len + 1);
    51        if (vn == NULL)
    52  	runtime_throw ("out of malloc memory");
    53        __builtin_memcpy (vn, vs, v.len);
    54        vn[v.len] = '\0';
    55        vs = vn;
    56      }
    57  
    58    setenv ((const char *) ks, (const char *) vs, 1);
    59  
    60  #else /* !defined(HAVE_SETENV) */
    61  
    62    len = k.len + v.len + 2;
    63    kn = malloc (len);
    64    if (kn == NULL)
    65      runtime_throw ("out of malloc memory");
    66    __builtin_memcpy (kn, ks, k.len);
    67    kn[k.len] = '=';
    68    __builtin_memcpy (kn + k.len + 1, vs, v.len);
    69    kn[k.len + v.len + 1] = '\0';
    70    putenv ((char *) kn);
    71    kn = NULL; /* putenv takes ownership of the string.  */
    72  
    73  #endif /* !defined(HAVE_SETENV) */
    74  
    75    if (kn != NULL)
    76      free (kn);
    77    if (vn != NULL)
    78      free (vn);
    79  }