View source for Solaris/FOSS specfiles example1

Writing conditional Spec files

In general, the reason for writing a conditional spec file is so
that you don't have to rely on a CMS system to figure out which
version of a module you want to check out.  Like tke KDE4 on Solaris
project, there are several hundred spec files and easily double that
in support files (once all the DUDE tarfile conversions are completed)
so trying to go back a rev can be rather painful.  This wiki attempts
to clearly document the ease in which this can be handled.

Philosophy
: FOSS spec files care about src_ver or version
: explicit plists are used to catch differences between package revisions
: every decision should be based on a simple true/false decision.

: we don't want to maintain too many revisions internally to the spec, just enough to go back easily if something breaks, so current, and last working (or 2) is really all we want to support.  Otherwise, you have to be something of a mercurial guru to figure out how to get back the last working version.

'''Header, self explanatory'''
<syntaxhighlight lang="text">
# SPEC file for expat library.
#
# Copyright 2009 Ben Taylor
# Copyright 2008 Lukas Oboril
# Copyright 2008 Adriaan de Groot
# Copyright 2008 Stefan Teleman
#
# This file is released under the terms of an MIT / 1-clause BSD
# license. See the file LICENSE.MIT for details.
#
# Expat is a GNU library for xml parsing
</syntaxhighlight>

'''Package definition'''

src_ver is the variable that defines the package source version

<syntaxhighlight lang="text">
#
# Support expat-2.0.0 and 2.0.1. 2.0.1 now default.
#
%define src_name        expat
#%define src_ver                2.0.0
%define src_ver         2.0.1
Name:                   %{src_name}
Version:                %{src_ver}
SUNW_Pkg:               FOSS%{name}
%define src_rev         2

Summary:                XML parser library
License:                MIT
Source:                 %{site_sourceforge}/expat/%{src_name}-%{src_ver}.tar.gz
Url:                    http://expat.sf.net/
Group:                  System/Libraries

%description
Expat is an XML parser library written in C. It is a
stream-oriented parser in which an application registers
handlers for things the parser might find in the XML
document (like start tags).
</syntaxhighlight>

'''versioning conditional defines'''

<syntaxhighlight lang="text">
%define is_ver_2_0_0    %( test %{src_ver} = "2.0.0" && echo 1 || echo 0)
%define is_ver_2_0_1    %( test %{src_ver} = "2.0.1" && echo 1 || echo 0)
</syntaxhighlight>

during development, it's possible that we could iterate through
several versions.  These versions will likely be important to the
base-<module>.spec file, since the intention is to keep patches
as history, and use the '''version''' test to manage them. Again,
we really ought to keep no more than 1 working, and 2 previous
versions, otherwise the clutter will become a bit difficult to
deal with.

On a project like KDE4 on Solaris, there are so many working parts,
being about to back rev a module quickly has really been useful.

In the case where we need to test a package
minor rev greater than, equal to 1, we can do the following:

<syntaxhighlight lang="text">
%define expat_minor_rev      %( echo %{src_ver} | cut -f3 -d\. )
%define expat_rev_ge_2_0_1   %( test ${expat_minor_rev} -ge 1 && echo 1 || echo 0)
</syntaxhighlight>

'''collection of standard includes use for the KDE4 project'''
<syntaxhighlight lang="text">

%include base-foss-header.inc
%include foss-paths.inc

%include foss-common32.inc
%use base32 = base-expat.spec
%if %has64
%include foss-common64.inc
%use base64 = base-expat.spec
%endif

%include base-foss-common.inc
</syntaxhighlight>

the base-expat.spec is used for both 32-bit and 64-bit building, and on occasion, you'll find that some package didn't honor the .../lib/{amd64|sparcv9} construct, and you'll use the %install area to manually clean that up.

'''Explicit plist'''
<syntaxhighlight lang="text">
%files
%dir %attr (0755, root, sys) /opt
%dir %attr (0755, root, sys) %{_prefix}
%defattr (-, root, bin)
%dir %attr (0755, root, bin) %{_bindir}
%{_bindir}/xmlwf

%dir %attr (0755, root, bin) %{_libdir}
%{_libdir}/libexpat.so
%{_libdir}/libexpat.so.1
</syntaxhighlight>

'''How to use versions with explicit plists'''

Why use an explicit plist? As another example,ncurses-5.6. For
18 months, the plist was in place, explicitly defined. During
the change to full spec, a minor change occured, rather
unintentionally, and another set of libraries built which would
have never been identified had a global plist been used.

Here, even a minor revision of the package generated
a new minor revision of the shared library. Here we
would use an explicit version test.

For a file such as an include file, we might use
a '''''%if %{expat_minor_ge_2_0_1}''''' construct instead.

This model works good for the FOSS packages, but for
the KDE4 modules, we've agreed that the library versioning
will cause probably more churn in the spec files than is
gained by having explicit versioning for those.

<syntaxhighlight lang="text">
%if %{is_ver_2_0_0}
%{_libdir}/libexpat.so.1.5.0
%endif

%if %{is_ver_2_0_1}
%{_libdir}/libexpat.so.1.5.2
%endif
</syntaxhighlight>

'''Explicit plist continued....'''

<syntaxhighlight lang="text">
%dir %attr (0755, root, bin) %{_includedir}
%{_includedir}/expat.h
%{_includedir}/expat_external.h

%dir %attr (0755, root, sys) %{_datadir}
%dir %attr (0755, root, bin) %{_mandir}
%{_mandir}/man1/xmlwf.1

%if %{has64}
%dir %attr (0755, root, bin) %{_bindir}/%{_arch64}
%{_bindir}/%{_arch64}/xmlwf

%dir %attr (0755, root, bin) %{_libdir}/%{_arch64}
%{_libdir}/%{_arch64}/libexpat.so
%{_libdir}/%{_arch64}/libexpat.so.1
%if %{is_ver_2_0_0}
%{_libdir}/%{_arch64}/libexpat.so.1.5.0
%endif
%if %{is_ver_2_0_1}
%{_libdir}/%{_arch64}/libexpat.so.1.5.2
%endif

%endif

%changelog
* Tue Dec  1 2009 - bentaylor.solx86@gmail.com
- convrt to spec, add explicit plist
- add upgrade to version 2.0.1
* Wed Oct  1 2008 - groot@kde.org
- Turned back into a spec file
* Thu Jan 17 2008 - oboril.lukas@gmail.com
- Initial version
</syntaxhighlight>