emacs/m4/getline.m4

# getline.m4 serial 33

dnl Copyright (C) 1998-2003, 2005-2007, 2009-2024 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])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

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

  AC_CHECK_DECLS_ONCE([getline])

  gl_CHECK_FUNCS_ANDROID([getline], [[#include <stdio.h>]])
  if test $ac_cv_func_getline = yes; then
    dnl Found it in some library.  Verify that it works.
    AC_CACHE_CHECK([for working getline function],
      [am_cv_func_working_getline],
      [echo fooNbarN | tr -d '\012' | tr N '\012' > conftest.data
       AC_RUN_IFELSE([AC_LANG_SOURCE([[
#    include <stdio.h>
#    include <stdlib.h>
#    include <string.h>
    int main ()
    {
      FILE *in = fopen ("./conftest.data", "r");
      if (!in)
        return 1;
      {
        /* Test result for a NULL buffer and a zero size.
           Based on a test program from Karl Heuer.  */
        char *line = NULL;
        size_t siz = 0;
        int len = getline (&line, &siz, in);
        if (!(len == 4 && line && strcmp (line, "foo\n") == 0))
          { free (line); fclose (in); return 2; }
        free (line);
      }
      {
        /* Test result for a NULL buffer and a non-zero size.
           This crashes on FreeBSD 8.0.  */
        char *line = NULL;
        size_t siz = (size_t)(~0) / 4;
        if (getline (&line, &siz, in) == -1)
          { fclose (in); return 3; }
        free (line);
      }
      fclose (in);
      return 0;
    }
    ]])],
         [am_cv_func_working_getline=yes],
         [am_cv_func_working_getline=no],
         [dnl We're cross compiling.
          dnl Guess it works on glibc2 systems and musl systems.
          AC_EGREP_CPP([Lucky GNU user],
            [
#include <features.h>
#ifdef __GNU_LIBRARY__
 #if (__GLIBC__ >= 2) && !defined __UCLIBC__
  Lucky GNU user
 #endif
#endif
            ],
            [am_cv_func_working_getline="guessing yes"],
            [case "$host_os" in
               *-musl* | midipix*) am_cv_func_working_getline="guessing yes" ;;
               *)                  am_cv_func_working_getline="$gl_cross_guess_normal" ;;
             esac
            ])
         ])
      ])
  else
    am_cv_func_working_getline=no
    case "$gl_cv_onwards_func_getline" in
      future*) REPLACE_GETLINE=1 ;;
    esac
  fi

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

  case "$am_cv_func_working_getline" in
    *yes) ;;
    *)
      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
      ;;
  esac
])

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