Node:Cache Checkpointing, Previous:Cache Files, Up:Caching Results

Cache Checkpointing

If your configure script, or a macro called from configure.ac, happens to abort the configure process, it may be useful to checkpoint the cache a few times at key points using AC_CACHE_SAVE. Doing so will reduce the amount of time it takes to re-run the configure script with (hopefully) the error that caused the previous abort corrected.

AC_CACHE_LOAD

Macro

Loads values from existing cache file, or creates a new cache file if a cache file is not found. Called automatically from AC_INIT.

AC_CACHE_SAVE

Macro

Flushes all cached values to the cache file. Called automatically from AC_OUTPUT, but it can be quite useful to call AC_CACHE_SAVE at key points in configure.ac.

For instance:

 ... AC_INIT, etc. ...
# Checks for programs.
AC_PROG_CC
AC_PROG_GCC_TRADITIONAL
 ... more program checks ...
AC_CACHE_SAVE

# Checks for libraries.
AC_CHECK_LIB(nsl, gethostbyname)
AC_CHECK_LIB(socket, connect)
 ... more lib checks ...
AC_CACHE_SAVE

# Might abort...
AM_PATH_GTK(1.0.2,, [AC_MSG_ERROR([GTK not in path])])
AM_PATH_GTKMM(0.9.5,, [AC_MSG_ERROR([GTK not in path])])
 ... AC_OUTPUT, etc. ...