grub2/m4/getline.m4

# getline.m4 serial 21

dnl Copyright (C) 1998-2003, 2005-2007, 2009-2010 Free Software Foundation,
dnl Inc.
dnl
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_PREREQ([2.59])

dnl See if there's a working, system-supplied version of the getline function.
dnl We can't just do AC_REPLACE_FUNCS([getline]) because some systems
dnl have a function by that name in -linet that doesn't have anything
dnl to do with the function we need.
AC_DEFUN([gl_FUNC_GETLINE],
[
  AC_REQUIRE([gl_STDIO_H_DEFAULTS])

  dnl Persuade glibc <stdio.h> to declare getline().
  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])

  AC_CHECK_DECLS_ONCE([getline])

  gl_getline_needs_run_time_check=no
  AC_CHECK_FUNC([getline],
                [dnl Found it in some library.  Verify that it works.
                 gl_getline_needs_run_time_check=yes],
                [am_cv_func_working_getline=no])
  if test $gl_getline_needs_run_time_check = yes; then
    AC_CACHE_CHECK([for working getline function], [am_cv_func_working_getline],
    [echo fooNbarN | tr -d '\012' | tr N '\012' > conftest.data
    AC_RUN_IFELSE([AC_LANG_SOURCE([[
#    include <stdio.h>
#    include <stdlib.h>
#    include <string.h>
    int main ()
    {
      FILE *in = fopen ("./conftest.data", "r");
      if (!in)
        return 1;
      {
        /* Test result for a NULL buffer and a zero size.
           Based on a test program from Karl Heuer.  */
        char *line = NULL;
        size_t siz = 0;
        int len = getline (&line, &siz, in);
        if (!(len == 4 && line && strcmp (line, "foo\n") == 0))
          return 1;
      }
      {
        /* Test result for a NULL buffer and a non-zero size.
           This crashes on FreeBSD 8.0.  */
        char *line = NULL;
        size_t siz = (size_t)(~0) / 4;
        if (getline (&line, &siz, in) == -1)
          return 1;
      }
      return 0;
    }
    ]])], [am_cv_func_working_getline=yes] dnl The library version works.
    , [am_cv_func_working_getline=no] dnl The library version does NOT work.
    , dnl We're cross compiling. Assume it works on glibc2 systems.
      [AC_EGREP_CPP([Lucky GNU user],
         [
#include <features.h>
#ifdef __GNU_LIBRARY__
 #if (__GLIBC__ >= 2)
  Lucky GNU user
 #endif
#endif
         ],
         [am_cv_func_working_getline=yes],
         [am_cv_func_working_getline=no])]
    )])
  fi

  if test $ac_cv_have_decl_getline = no; then
    HAVE_DECL_GETLINE=0
  fi

  if test $am_cv_func_working_getline = no; then
    dnl Set REPLACE_GETLINE always: Even if we have not found the broken
    dnl getline function among $LIBS, it may exist in libinet and the
    dnl executable may be linked with -linet.
    REPLACE_GETLINE=1
    AC_LIBOBJ([getline])

    gl_PREREQ_GETLINE
  fi
])

# Prerequisites of lib/getline.c.
AC_DEFUN([gl_PREREQ_GETLINE],
[
  gl_FUNC_GETDELIM
])