$ autoconf
configure.in:4: error: possibly undefined macro: AM_INIT_AUTOMAKE
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
configure.in:22: error: possibly undefined macro: AC_DEFINE
configure.in:30: error: possibly undefined macro: AC_MSG_WARN
configure.in:108: error: possibly undefined macro: AC_C99_FUNC_LRINT
configure.in:109: error: possibly undefined macro: AC_C99_FUNC_LRINTF