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      1 # eoverflow.m4 serial 1
      2 dnl Copyright (C) 2004 Free Software Foundation, Inc.
      3 dnl This file is free software; the Free Software Foundation
      4 dnl gives unlimited permission to copy and/or distribute it,
      5 dnl with or without modifications, as long as this notice is preserved.
      6 
      7 dnl From Bruno Haible.
      8 
      9 # The EOVERFLOW errno value ought to be defined in <errno.h>, according to
     10 # POSIX.  But some systems (like AIX 3) don't define it, and some systems
     11 # (like OSF/1) define it when _XOPEN_SOURCE_EXTENDED is defined.
     12 
     13 # Define EOVERFLOW as a C macro and as a substituted macro in such a way that
     14 # 1. on all systems, after inclusion of <errno.h>, EOVERFLOW is usable,
     15 # 2. on systems where EOVERFLOW is defined elsewhere, we use the same numeric
     16 #    value.
     17 
     18 AC_DEFUN([gl_EOVERFLOW],
     19 [
     20   AC_REQUIRE([AC_PROG_CC])dnl
     21 
     22   AC_CACHE_CHECK([for EOVERFLOW], ac_cv_decl_EOVERFLOW, [
     23     AC_EGREP_CPP(yes,[
     24 #include <errno.h>
     25 #ifdef EOVERFLOW
     26 yes
     27 #endif
     28       ], have_eoverflow=1)
     29     if test -n "$have_eoverflow"; then
     30       dnl EOVERFLOW exists in <errno.h>. Don't need to define EOVERFLOW ourselves.
     31       ac_cv_decl_EOVERFLOW=yes
     32     else
     33       AC_EGREP_CPP(yes,[
     34 #define _XOPEN_SOURCE_EXTENDED 1
     35 #include <errno.h>
     36 #ifdef EOVERFLOW
     37 yes
     38 #endif
     39         ], have_eoverflow=1)
     40       if test -n "$have_eoverflow"; then
     41         dnl EOVERFLOW exists but is hidden.
     42         dnl Define it to the same value.
     43         _AC_COMPUTE_INT([EOVERFLOW], ac_cv_decl_EOVERFLOW, [
     44 #define _XOPEN_SOURCE_EXTENDED 1
     45 #include <errno.h>
     46 /* The following two lines are a workaround against an autoconf-2.52 bug.  */
     47 #include <stdio.h>
     48 #include <stdlib.h>
     49 ])
     50       else
     51         dnl EOVERFLOW isn't defined by the system. Define EOVERFLOW ourselves, but
     52         dnl don't define it as EINVAL, because snprintf() callers want to
     53         dnl distinguish EINVAL and EOVERFLOW.
     54         ac_cv_decl_EOVERFLOW=E2BIG
     55       fi
     56     fi
     57   ])
     58   if test "$ac_cv_decl_EOVERFLOW" != yes; then
     59     AC_DEFINE_UNQUOTED([EOVERFLOW], [$ac_cv_decl_EOVERFLOW],
     60                        [Define as good substitute value for EOVERFLOW.])
     61     EOVERFLOW="$ac_cv_decl_EOVERFLOW"
     62     AC_SUBST(EOVERFLOW)
     63   fi
     64 ])
     65