AC_DEFINE_SUB_PATH(DEFNAME, varname, description)
, 

2005-08-01

Guido U. Draheim <guidod@gmx.de>

GPLWithACException
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation. As a special exception, the respective Autoconf Macro's copyright owner gives unlimited permission to copy, distribute and modify the configure scripts that are the output of Autoconf when processing the Macro. You need not follow the terms of the GNU General Public License when using or distributing such scripts

guidod's Obsoleted (obsoleted)

• obsoleted Renamed to AC_DEFINE_SUB_PATH.

look at varname and detect the subpath that it contains relative to $prefix/$exec_prefix

If the path is indeed relative to $prefix/$exec_prefix, then a single "./" (dotslash) is prepended, otherwise it can be seen as an absolute path that can not be moved, which you possibly do for "/etc" files, or even those ending up in "/lib/modules" or "/winnt/system".

this macro is not very intelligent, it's just a first try in this direction. It does currently just look into the current patterns, and replaces a ${prefix} with a simple dot. Amazingly, it works quite well for most packages.

correct usage: in configure ac

  AC_DEFINE_DIR([EPREFIX], [exec_prefix], [--exec-prefix or default])
  AC_DEFINE_SUB_PATH([PATH_LIBDIR], [libdir], [--bindir subdir])
  AC_DEFINE_UNQUOTED([PACKAGE],"$PACKAGE", [Name of package])

in "C"

  static const char _libdir[] = PATH_LIBDIR; /* configure default */
  char* libdir;
  char* eprefix = getenv (PACKAGE "DIR");
  if (! eprefix) eprefix = EPREFIX; /* default */
  if (*_libdir != '.') libdir = strdup(_libdir);
  else {
     libdir = malloc(strlen(eprefix) + strlen(_libdir) + 2);
     strcpy(libdir, eprefix);
     strcat(libdir, PATH_DELIMITER_STRING);
     strcat(libdir, _libdir);
  }
  ...
  free (libdir);

AC_DEFINE_SUB_PATHS(varnames)

look for the given various install-paths that largely depend on either ${prefix} or ${exec_prefix}. Just cut out the prefix and ac_define the value. The value is uppercased and PATH_ prepended ie. ac_define_sub_paths(bindir libdir pkgdatadir) will create the defines PATH_BINDIR PATH_LIBDIR PATH_PKGDATADIR - see posix' include/paths.h that creates _PATH_DEV and friends.

AC_DEFUN([AC_DEFINE_SUB_PATH],
[dnl
  test "_$prefix" = _NONE && prefix="$ac_default_prefix"
  test "_$exec_prefix" = _NONE && exec_prefix='${prefix}'
  P=`echo ifelse( $2, , [$]$1, [$]$2) | sed -e 's:^\${[a-z_]*prefix}:.:'`
  ifelse ($3, ,
    AC_DEFINE($1, $P, [sub path $2]),
    AC_DEFINE($1, $P, $3))
])

AC_DEFUN([AC_DEFINE_SUB_PATHS],
[dnl
  test "_$prefix" = _NONE && prefix="$ac_default_prefix"
  test "_$exec_prefix" = _NONE && exec_prefix='${prefix}'
  for i in $1 ; do
  P=`echo \$$i | sed -e 's:^\${[a-z_]*prefix}:.:'`
  V=`echo path_$i | sed -e 'y:abcdefghijklmnopqrstuvwxyz:ABCDEFGHIJKLMNOPQRSTUVWXYZ:'`
    AC_DEFINE($V, $P, [sub path $i]),
])