gcc/ada/env.c

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                                  E N V                                   *
   6  *                                                                          *
   7  *                          C Implementation File                           *
   8  *                                                                          *
   9  *            Copyright (C) 2005-2023, Free Software Foundation, Inc.       *
  10  *                                                                          *
  11  * GNAT is free software;  you can  redistribute it  and/or modify it under *
  12  * terms of the  GNU General Public License as published  by the Free Soft- *
  13  * ware  Foundation;  either version 3,  or (at your option) any later ver- *
  14  * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
  15  * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *
  16  * or FITNESS FOR A PARTICULAR PURPOSE.                                     *
  17  *                                                                          *
  18  * As a special exception under Section 7 of GPL version 3, you are granted *
  19  * additional permissions described in the GCC Runtime Library Exception,   *
  20  * version 3.1, as published by the Free Software Foundation.               *
  21  *                                                                          *
  22  * You should have received a copy of the GNU General Public License and    *
  23  * a copy of the GCC Runtime Library Exception along with this program;     *
  24  * see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    *
  25  * <http://www.gnu.org/licenses/>.                                          *
  26  *                                                                          *
  27  * GNAT was originally developed  by the GNAT team at  New York University. *
  28  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  29  *                                                                          *
  30  ****************************************************************************/
  31
  32 #ifdef IN_RTS
  33 # include "runtime.h"
  34 # include <stdio.h>
  35 # include <stdlib.h>
  36 # include <string.h>
  37
  38 /* We don't have libiberty, so use malloc.  */
  39 # define xmalloc(S) malloc (S)
  40 #else /* IN_RTS */
  41 # include "config.h"
  42 # include "system.h"
  43 #endif /* IN_RTS */
  44
  45 #if defined (__MINGW32__)
  46 #include <stdlib.h>
  47 #endif
  48
  49 #if defined (__APPLE__) \
  50    && !(defined (__arm__) \
  51         || defined (__arm64__) \
  52         || defined (__IOS_SIMULATOR__))
  53 /* On Darwin, _NSGetEnviron must be used for shared libraries; but it is not
  54    available on iOS (on device or on simulator).  */
  55 #include <crt_externs.h>
  56 #endif
  57
  58 #if defined (__vxworks)
  59   #include <vxWorks.h>
  60   #include <version.h>
  61
  62   #if defined (__RTP__)
  63     /* On VxWorks 6 Real-Time process mode, environ is defined in unistd.h.  */
  64     #include <unistd.h>
  65   #elif defined (VTHREADS)
  66     /* VTHREADS mode applies to both VxWorks 653 and VxWorks MILS. The
  67        inclusion of vThreadsData.h is necessary to workaround a bug with
  68        envLib.h on VxWorks MILS and VxWorks 653.  */
  69     #include <vThreadsData.h>
  70     #include <envLib.h>
  71   #else
  72     /* Kernel mode */
  73     #include <envLib.h>
  74   #endif
  75 #endif
  76
  77 #ifdef __cplusplus
  78 extern "C" {
  79 #endif
  80
  81 #ifdef VMS
  82 #include <vms/descrip.h>
  83 #endif
  84
  85 #include "env.h"
  86
  87 void
  88 __gnat_getenv (char *name, int *len, char **value)
  89 {
  90   *value = getenv (name);
  91   if (!*value)
  92     *len = 0;
  93   else
  94     *len = strlen (*value);
  95
  96   return;
  97 }
  98
  99 void
 100 __gnat_setenv (char *name, char *value)
 101 {
 102 #if (defined (__vxworks) && (defined (__RTP__) || _WRS_VXWORKS_MAJOR >= 7)) \
 103     || defined (__APPLE__)
 104   setenv (name, value, 1);
 105
 106 #else
 107   size_t size = strlen (name) + strlen (value) + 2;
 108   char *expression;
 109
 110   expression = (char *) xmalloc (size * sizeof (char));
 111
 112   sprintf (expression, "%s=%s", name, value);
 113   putenv (expression);
 114 #if defined (__MINGW32__) || defined (__vxworks)
 115   /* putenv for Windows and VxWorks 6 kernel modules makes a copy of the
 116      expression string, so we need to free it after the call to putenv. */
 117   free (expression);
 118 #endif
 119 #endif
 120 }
 121
 122 char **
 123 __gnat_environ (void)
 124 {
 125 #if defined (__MINGW32__)
 126   return _environ;
 127 #elif defined (__sun__)
 128   extern char **_environ;
 129   return _environ;
 130 #elif defined (__APPLE__) \
 131      && !(defined (__arm__) \
 132           || defined (__arm64__)                \
 133           || defined (__IOS_SIMULATOR__))
 134   return *_NSGetEnviron ();
 135 #elif ! (defined (__vxworks))
 136   extern char **environ;
 137   return environ;
 138 #else
 139   #if defined (__RTP__) || defined (VTHREADS)
 140     return environ;
 141   #else
 142     /* For VxWorks kernel modules use envGet to get the task's environment
 143        (either the task's private environment if it has one or the global
 144        environment otherwise). taskId parameter of 0 refers to the current
 145        task (the VxWorks documentation says to use NULL but the compiler
 146        complains that taskId is an int rather than a pointer. Internally,
 147        VxWorks uses 0 as well). */
 148     return envGet (0);
 149   #endif
 150 #endif
 151 }
 152
 153 void __gnat_unsetenv (char *name)
 154 {
 155 #if defined (__hpux__) || defined (__sun__) \
 156      || (defined (__vxworks) && ! defined (__RTP__) \
 157           && _WRS_VXWORKS_MAJOR <= 6) \
 158      || defined (_AIX) || defined (__Lynx__)
 159
 160   /* On Solaris and HP-UX there is no function to clear an environment
 161      variable. So we look for the variable in the environ table and delete it
 162      by setting the entry to NULL. This can clearly cause some memory leaks
 163      but free cannot be used on this context as not all strings in the environ
 164      have been allocated using malloc. To avoid this memory leak another
 165      method can be used. It consists in forcing the reallocation of all the
 166      strings in the environ table using malloc on the first call on the
 167      functions related to environment variable management. The disadvantage
 168      is that if a program makes a direct call to getenv the return string
 169      may be deallocated at some point. */
 170   /* Note that on AIX, unsetenv is not supported on 5.1 but it is on 5.3.
 171      As we are still supporting AIX 5.1 we cannot use unsetenv */
 172   char **env = __gnat_environ ();
 173   int index = 0;
 174   size_t size = strlen (name);
 175
 176   while (env[index] != NULL) {
 177      if (strlen (env[index]) > size) {
 178        if (strstr (env[index], name) == env[index] &&
 179            env[index][size] == '=') {
 180 #if defined (__vxworks)
 181          /* on Vxworks we are sure that the string has been allocated using
 182             malloc */
 183          free (env[index]);
 184 #endif
 185          while (env[index] != NULL) {
 186           env[index]=env[index + 1];
 187           index++;
 188          }
 189        } else
 190            index++;
 191      } else
 192          index++;
 193   }
 194 #elif defined (__MINGW32__)
 195   /* On Windows platform putenv ("key=") is equivalent to unsetenv (a
 196      subsequent call to getenv ("key") will return NULL and not the "\0"
 197      string */
 198   size_t size = strlen (name) + 2;
 199   char *expression;
 200   expression = (char *) xmalloc (size * sizeof (char));
 201
 202   sprintf (expression, "%s=", name);
 203   putenv (expression);
 204   free (expression);
 205 #else
 206   unsetenv (name);
 207 #endif
 208 }
 209
 210 void __gnat_clearenv (void)
 211 {
 212 #if defined (__sun__) \
 213   || (defined (__vxworks) && !defined (__RTP__) && _WRS_VXWORKS_MAJOR <= 6) \
 214   || defined (__Lynx__) \
 215   || defined (__PikeOS__)
 216   /* On Solaris, VxWorks kernel pre 7, and Lynx there is no system
 217      call to unset a variable or to clear the environment so set all
 218      the entries in the environ table to NULL (see comment in
 219      __gnat_unsetenv for more explanation). */
 220   char **env = __gnat_environ ();
 221   int index = 0;
 222
 223   while (env[index] != NULL) {
 224     env[index]=NULL;
 225     index++;
 226   }
 227 #elif defined (__MINGW32__) || defined (__FreeBSD__) || defined (__APPLE__) \
 228    || (defined (__vxworks) && defined (__RTP__) || _WRS_VXWORKS_MAJOR >= 7) \
 229    || defined (__CYGWIN__) \
 230    || defined (__NetBSD__) || defined (__OpenBSD__) || defined (__rtems__) \
 231    || defined (__DragonFly__) || defined (__DJGPP__)
 232   /* On Windows, FreeBSD and MacOS there is no function to clean all the
 233      environment but there is a "clean" way to unset a variable. So go
 234      through the environ table and call __gnat_unsetenv on all entries */
 235   char **env = __gnat_environ ();
 236   size_t size;
 237
 238   while (env[0] != NULL) {
 239     size = 0;
 240     while (env[0][size] != '=')
 241       size++;
 242     /* create a string that contains "name" */
 243     size++;
 244     {
 245       char *expression;
 246       expression = (char *) xmalloc (size * sizeof (char));
 247       strncpy (expression, env[0], size);
 248       expression[size - 1] = 0;
 249       __gnat_unsetenv (expression);
 250       free (expression);
 251     }
 252   }
 253 #else
 254   clearenv ();
 255 #endif
 256 }
 257
 258 #ifdef __cplusplus
 259 }
 260 #endif