xsrc/44942: certain generated xsrc files don't rebuild

[dholland%NetBSD.org@localhost]

>Number:         44942
>Category:       xsrc
>Synopsis:       certain generated xsrc files don't rebuild
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    xsrc-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat May 07 00:15:00 +0000 2011
>Originator:     David A. Holland
>Release:        (current)
>Organization:
>Environment:
n/a
>Description:

There's an ugly mess in bsd.x11.mk that generates .pc files. There are
other less prominent rules in there that also contribute content to
build products. None of these build products depend on bsd.x11.mk, so
build.sh -u won't regenerate them when bsd.x11.mk changes. This causes
update builds to diverge from fresh builds and sometimes break, or
break X apps. See PR 43942 for an example.

However, depending on bsd.x11.mk is undesirable and messy because we
rely on make's include path to find it.

>How-To-Repeat:

>Fix:

Change all the nontrivial build rules into standalone shell scripts
and make the build products depend on the shell scripts that generate
them. This is not entirely trivial.