gnulib/import/m4/d-ino.m4

   1 # serial 20
   2
   3 dnl From Jim Meyering.
   4 dnl
   5 dnl Check whether struct dirent has a member named d_ino.
   6 dnl
   7
   8 # Copyright (C) 1997, 1999-2001, 2003-2004, 2006-2007, 2009-2019 Free Software
   9 # Foundation, Inc.
  10
  11 # This file is free software; the Free Software Foundation
  12 # gives unlimited permission to copy and/or distribute it,
  13 # with or without modifications, as long as this notice is preserved.
  14
  15 AC_DEFUN([gl_CHECK_TYPE_STRUCT_DIRENT_D_INO],
  16   [AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  17    AC_CACHE_CHECK([for d_ino member in directory struct],
  18                   [gl_cv_struct_dirent_d_ino],
  19      [AC_RUN_IFELSE(
  20         [AC_LANG_PROGRAM(
  21            [[#include <sys/types.h>
  22              #include <sys/stat.h>
  23              #include <dirent.h>
  24            ]],
  25            [[DIR *dp = opendir (".");
  26              struct dirent *e;
  27              struct stat st;
  28              if (! dp)
  29                return 1;
  30              e = readdir (dp);
  31              if (! e)
  32                { closedir (dp); return 2; }
  33              if (lstat (e->d_name, &st) != 0)
  34                { closedir (dp); return 3; }
  35              if (e->d_ino != st.st_ino)
  36                { closedir (dp); return 4; }
  37              closedir (dp);
  38              return 0;
  39            ]])],
  40            [gl_cv_struct_dirent_d_ino=yes],
  41            [gl_cv_struct_dirent_d_ino=no],
  42            [case "$host_os" in
  43                             # Guess yes on glibc systems with Linux kernel.
  44               linux*-gnu*)  gl_cv_struct_dirent_d_ino="guessing yes" ;;
  45                             # Guess yes on musl systems with Linux kernel.
  46               linux*-musl*) gl_cv_struct_dirent_d_ino="guessing yes" ;;
  47                             # Guess no on native Windows.
  48               mingw*)       gl_cv_struct_dirent_d_ino="guessing no" ;;
  49                             # If we don't know, obey --enable-cross-guesses.
  50               *)            gl_cv_struct_dirent_d_ino="$gl_cross_guess_normal" ;;
  51             esac
  52            ])])
  53    case "$gl_cv_struct_dirent_d_ino" in
  54      *yes)
  55        AC_DEFINE([D_INO_IN_DIRENT], [1],
  56          [Define if struct dirent has a member d_ino that actually works.])
  57        ;;
  58    esac
  59   ]
  60 )