m4/jm-glibc-io.m4

   1 #serial 4
   2
   3 dnl From Jim Meyering.
   4 dnl
   5 dnl See if the glibc *_unlocked I/O macros are available.
   6 dnl Use only those *_unlocked macros that are declared.
   7 dnl
   8
   9 AC_DEFUN(jm_FUNC_GLIBC_UNLOCKED_IO,
  10   [
  11     # Kludge (not executed) to make autoheader do the right thing.
  12     if test a = b; then
  13       AC_CHECK_DECLS([clearerr_unlocked, feof_unlocked, ferror_unlocked,
  14         fflush_unlocked, fputc_unlocked, fread_unlocked, fwrite_unlocked,
  15         getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked])
  16     fi
  17
  18     io_functions='clearerr_unlocked feof_unlocked ferror_unlocked
  19     fflush_unlocked fputc_unlocked fread_unlocked fwrite_unlocked
  20     getc_unlocked getchar_unlocked putc_unlocked putchar_unlocked'
  21     for jm_io_func in $io_functions; do
  22       # Check for the existence of each function only if its declared.
  23       # Otherwise, we'd get the Solaris5.5.1 functions that are not
  24       # declared, and that have been removed from Solaris5.6.  The resulting
  25       # 5.5.1 binaries would not run on 5.6 due to shared library differences.
  26       AC_CHECK_DECLS([$jm_io_func],
  27                      jm_declared=yes,
  28                      jm_declared=no,
  29                      [#include <stdio.h>])
  30       if test $jm_declared = yes; then
  31         AC_CHECK_FUNCS($jm_io_func)
  32       fi
  33     done
  34   ]
  35 )