Reintroduce #5019 via metaconfig.

[metaconfig.git] / U / installdirs / inc_version_list.U

?RCS: $Id: inc_version_list.U,v $
?RCS:
?RCS: Copyright (c) 2000 Andy Dougherty
?RCS: 
?RCS: You may redistribute only under the terms of the Artistic Licence,
?RCS: as specified in the README file that comes with the distribution.
?RCS: You may reuse parts of this distribution only within the terms of
?RCS: that same Artistic Licence; a copy of which may be found at the root
?RCS: of the source tree for dist 3.0.
?RCS:
?RCS: $Log: inc_version_list.U,v $
?RCS:
?MAKE:inc_version_list inc_version_list_init: cat sed Getfile perl \
	version api_versionstring rm Myread archname prefix sitelib
?MAKE:	-pick add $@ %<
?Y:TOP
?S:inc_version_list:
?S:	This variable specifies the list of subdirectories in over
?S:	which perl.c:incpush() and lib/lib.pm will automatically
?S:	search when adding directories to @INC.  The elements in
?S:	the list are separated by spaces.  This is only useful
?S:	if you have a perl library directory tree structured like the
?S:	default one.  See INSTALL for how this works.  The versioned
?S:	site_perl directory was introduced in 5.005, so that is the
?S:	lowest possible value.
?S:	
?S:	This list includes architecture-dependent directories back to
?S:	version $api_versionstring (e.g. 5.5.640) and
?S:	architecture-independent directories all the way back to
?S:	5.005.
?S:.
?S:inc_version_list_init:
?S:     This variable holds the same list as inc_version_list, but
?S:	each item is enclosed in double quotes and separated by commas, 
?S:	suitable for use in the PERL_INC_VERSION_LIST initialization.
?S:.
?C:PERL_INC_VERSION_LIST:
?C:	This variable specifies the list of subdirectories in over
?C:	which perl.c:incpush() and lib/lib.pm will automatically
?C:	search when adding directories to @INC, in a format suitable
?C:	for a C initialization string.  See the inc_version_list entry
?C:	in Porting/Glossary for more details.
?C:.
?H:#define PERL_INC_VERSION_LIST $inc_version_list_init		/**/
?H:.
?T: stem d
: Determine list of previous versions to include in @INC
$cat > getverlist <<EOPL
#!$perl -w
use File::Basename;
\$api_versionstring = "$api_versionstring";
\$version = "$version";
\$sitelib = "$sitelib";
\$archname = "$archname";
EOPL
	$cat >> getverlist <<'EOPL'
# Can't have leading @ because metaconfig interprets it as a command!
;@inc_version_list=();
$stem=dirname($sitelib);
# Redo to do opendir/readdir? 
if (-d $stem) {
    chdir($stem);
    ;@candidates = glob("5.*");
}
else {
    ;@candidates = ();
}

# XXX ToDo:  These comparisons must be reworked when two-digit
# subversions come along, so that 5.7.10 compares as greater than
# 5.7.3!  By that time, hope that 5.6.x is sufficiently
# widespread that we can use the built-in version vectors rather
# than reinventing them here.  For 5.6.0, however, we must
# assume this script will likely be run by 5.005_0x.  --AD 1/2000.
foreach $d (@candidates) {
    if ($d lt $version) {
	if ($d ge $api_versionstring) {
	    unshift(@inc_version_list, "$d/$archname", $d);
	}
	elsif ($d ge "5.005") {
	    unshift(@inc_version_list, $d);
	}
    }
    else {
	# Skip newer version.  I.e. don't look in
	# 5.7.0 if we're installing 5.6.1.
    }
}

if (@inc_version_list) {
    print join(' ', @inc_version_list);
}
else {
    # Blank space to preserve value for next Configure run.
    print " ";
}
EOPL
chmod +x getverlist
case "$inc_version_list" in
'')	if test -x $perl; then
		dflt=`$perl getverlist`
	else
		dflt='none'
	fi
	;;
$undef) dflt='none' ;;
*)  dflt="$inc_version_list" ;;
esac
$cat <<'EOM'

In order to ease the process of upgrading, this version of perl 
can be configured to use modules built and installed with earlier 
versions of perl that were installed under $prefix.  Specify here
the list of earlier versions that this version of perl should check.
If Configure detected no earlier versions of perl installed under
$prefix, then the list will be empty.  Answer 'none' to tell perl
to not search earlier versions.

The default should almost always be sensible, so if you're not sure,
just accept the default.
EOM

rp='List of earlier versions to include in @INC?'
. ./myread
case "$ans" in
[Nn]one) inc_version_list=' ' ;;
*) inc_version_list="$ans" ;;
esac
case "$inc_version_list" in
''|' ') 
	inc_version_list_init='0';;
*)	inc_version_list_init=`echo $inc_version_list |
		$sed -e 's/^/"/' -e 's/ /","/g' -e 's/$/",0/'`
	;;
esac
$rm -f getverlist