1 | # serial 6 -*- Autoconf -*- |
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2 | # Enable extensions on systems that normally disable them. |
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3 | |
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4 | # Copyright (C) 2003, 2006, 2007, 2009 Free Software Foundation, Inc. |
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5 | # This file is free software; the Free Software Foundation |
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6 | # gives unlimited permission to copy and/or distribute it, |
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7 | # with or without modifications, as long as this notice is preserved. |
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8 | |
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9 | # This definition of AC_USE_SYSTEM_EXTENSIONS is stolen from CVS |
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10 | # Autoconf. Perhaps we can remove this once we can assume Autoconf |
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11 | # 2.62 or later everywhere, but since CVS Autoconf mutates rapidly |
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12 | # enough in this area it's likely we'll need to redefine |
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13 | # AC_USE_SYSTEM_EXTENSIONS for quite some time. |
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14 | |
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15 | m4_version_prereq([2.62],, [ |
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16 | |
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17 | # AC_USE_SYSTEM_EXTENSIONS |
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18 | # ------------------------ |
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19 | # Enable extensions on systems that normally disable them, |
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20 | # typically due to standards-conformance issues. |
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21 | # Remember that #undef in AH_VERBATIM gets replaced with #define by |
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22 | # AC_DEFINE. The goal here is to define all known feature-enabling |
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23 | # macros, then, if reports of conflicts are made, disable macros that |
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24 | # cause problems on some platforms (such as __EXTENSIONS__). |
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25 | AC_DEFUN([AC_USE_SYSTEM_EXTENSIONS], |
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26 | [AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl |
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27 | AC_BEFORE([$0], [AC_RUN_IFELSE])dnl |
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28 | |
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29 | AC_CHECK_HEADER([minix/config.h], [MINIX=yes], [MINIX=]) |
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30 | if test "$MINIX" = yes; then |
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31 | AC_DEFINE([_POSIX_SOURCE], [1], |
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32 | [Define to 1 if you need to in order for `stat' and other |
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33 | things to work.]) |
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34 | AC_DEFINE([_POSIX_1_SOURCE], [2], |
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35 | [Define to 2 if the system does not provide POSIX.1 features |
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36 | except with this defined.]) |
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37 | AC_DEFINE([_MINIX], [1], |
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38 | [Define to 1 if on MINIX.]) |
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39 | fi |
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40 | |
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41 | AH_VERBATIM([__EXTENSIONS__], |
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42 | [/* Enable extensions on AIX 3, Interix. */ |
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43 | #ifndef _ALL_SOURCE |
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44 | # undef _ALL_SOURCE |
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45 | #endif |
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46 | /* Enable GNU extensions on systems that have them. */ |
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47 | #ifndef _GNU_SOURCE |
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48 | # undef _GNU_SOURCE |
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49 | #endif |
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50 | /* Enable threading extensions on Solaris. */ |
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51 | #ifndef _POSIX_PTHREAD_SEMANTICS |
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52 | # undef _POSIX_PTHREAD_SEMANTICS |
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53 | #endif |
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54 | /* Enable extensions on HP NonStop. */ |
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55 | #ifndef _TANDEM_SOURCE |
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56 | # undef _TANDEM_SOURCE |
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57 | #endif |
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58 | /* Enable general extensions on Solaris. */ |
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59 | #ifndef __EXTENSIONS__ |
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60 | # undef __EXTENSIONS__ |
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61 | #endif |
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62 | ]) |
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63 | AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__], |
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64 | [ac_cv_safe_to_define___extensions__], |
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65 | [AC_COMPILE_IFELSE( |
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66 | [AC_LANG_PROGRAM([ |
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67 | # define __EXTENSIONS__ 1 |
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68 | AC_INCLUDES_DEFAULT])], |
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69 | [ac_cv_safe_to_define___extensions__=yes], |
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70 | [ac_cv_safe_to_define___extensions__=no])]) |
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71 | test $ac_cv_safe_to_define___extensions__ = yes && |
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72 | AC_DEFINE([__EXTENSIONS__]) |
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73 | AC_DEFINE([_ALL_SOURCE]) |
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74 | AC_DEFINE([_GNU_SOURCE]) |
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75 | AC_DEFINE([_POSIX_PTHREAD_SEMANTICS]) |
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76 | AC_DEFINE([_TANDEM_SOURCE]) |
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77 | ])# AC_USE_SYSTEM_EXTENSIONS |
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78 | |
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79 | ]) |
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