Greets,
One of the problems we must address in order to enable compiled extensions for
Lucy is the installation of the Lucy C header files.
Because Lucy gets compiled once for every host language installation rather
than once per system, the headers must go in a per-host-install location
rather than a global location such as /usr/local/include (which isn't portable
anyway). For Perl, the logical place would seem to be the perl 5 lib
directories.
The DBI distro provides a useful example. It installs its .h files into the
architecture-specific tree of the lib dirs, and the docs for DBI::DBD show how
to use the function dbd_dbi_arch_dir() to build a list of include dirs:
http://search.cpan.org/perldoc?DBI::DBD
my $dbi_arch_dir = dbd_dbi_arch_dir();
if (exists($opts{INC})) {
return {INC => "$opts{INC} -I$dbi_arch_dir"};
} else {
return {INC => "-I$dbi_arch_dir"};
}
See also the Makefile.PL for DBD::Pg for an adaptation of the instructions in
DBI::DBD.
We can provide similar functionality from Lucy.pm. Here's how a build script
for a distro which extends Lucy might use it:
eval "use Lucy;";
if ($@) {
warn "Can't load Lucy;
exit(0);
}
my $include_dirs = Lucy->include_dirs;
my $inc = "";
$inc .= "-I$_ " for @$include_dirs;
At first, I imagine include_dirs() returning only a single directory.
However, in the future we may break out Clownfish, and perhaps include_dirs()
should return the include paths for recursive dependencies:
package Lucy;
use Clownfish;
sub include_dirs {
my $dirs = Clownfish->include_dirs;
push @$dirs, _lucy_include_dir();
return $dirs;
}
For the actual header tree, how about a dedicated directory at the following
location?
catdir( $ARCH_DIR, 'auto', 'Lucy', '_include' );
Thoughts?
Marvin Humphrey
