[cmake-developers] [CMake 0013072]: Allow CPack to generate tar.xz archives

Mantis Bug Tracker mantis at public.kitware.com
Mon Jun 25 05:22:18 EDT 2012


The following issue is now in status NEW (again) 
====================================================================== 
http://cmake.org/Bug/view.php?id=13072 
====================================================================== 
Reported By:                Mario Lang
Assigned To:                Eric NOULARD
====================================================================== 
Project:                    CMake
Issue ID:                   13072
Category:                   CPack
Reproducibility:            N/A
Severity:                   feature
Priority:                   normal
Status:                     new
====================================================================== 
Date Submitted:             2012-03-29 16:33 CEST
Last Modified:              2012-06-25 11:22 CEST
====================================================================== 
Summary:                    Allow CPack to generate tar.xz archives
Description: 
For my project I'd like to use CPack to generate tar.xz source archives.
After a bit of poking around in the git repository I realized that xz support is
already there in
the underlying library for handling archives.  However, there is no Generator
for TXZ.
The attached patch adds the necessary generator.  Tested and works as expected
for me.
I can set(CPACK_SOURCE_GENERATOR "TGZ;TXZ;") now and the result is just as
expected.
A second patch (also to be attached) adds the CPACK_BINARY_TXZ and
CPACK_SOURCE_TXZ options as well.

======================================================================
Relationships       ID      Summary
----------------------------------------------------------------------
duplicate of        0011040 TXZ support to cpack
====================================================================== 

---------------------------------------------------------------------- 
 (0029008) Eric NOULARD (developer) - 2012-03-30 17:40
 http://cmake.org/Bug/view.php?id=13072#c29008 
---------------------------------------------------------------------- 
This looks fine but unfortnately this is may not be enough.

CMake should build on any host, LZMA lib being installed or not.
In order to achieve this for Bzip2, zip, z and gz compression
CMake includes:

Utilities/cmbzip2
Utilities/zlib

in its source tree.
Then options:

CMAKE_USE_SYSTEM_BZIP2 and CMAKE_USE_SYSTEM_ZLIB are used to toggle between
system version and shipped-in version of those libs.

What would happen if CMake is compiled on a host where lzma lib is not
installed?

Will it fail to compile or will CPack have a non-functional TXZ generator? 

---------------------------------------------------------------------- 
 (0029010) Eric NOULARD (developer) - 2012-03-30 17:52
 http://cmake.org/Bug/view.php?id=13072#c29010 
---------------------------------------------------------------------- 
Just remembered that there was a sibling bug closed some time ago,
I did add the relationship, but read David's comment about portability:

http://public.kitware.com/Bug/view.php?id=11040#c24155 

---------------------------------------------------------------------- 
 (0029026) Mario Lang (reporter) - 2012-04-01 09:59
 http://cmake.org/Bug/view.php?id=13072#c29026 
---------------------------------------------------------------------- 
> What would happen if CMake is compiled on a host where lzma lib is not
installed?
> Will it fail to compile or will CPack have a non-functional TXZ generator?

Right now, Aas far as I can see, CPack will have a TXZ generator that reports
that it was built without lzma support.
cmlibarchive has ifdefs for HAVE_LZMA and will provide stub functions with a
warning.
>From my POV, thats fine since TXZ is not enabled by default.
If a user chooses to enable TXZ they will either have success or get an
appropriate error from CPack. 

---------------------------------------------------------------------- 
 (0029027) Eric NOULARD (developer) - 2012-04-01 10:39
 http://cmake.org/Bug/view.php?id=13072#c29027 
---------------------------------------------------------------------- 
Hi Mario,

I let Kitware guys give their opinion on this, but CMake tries to avoid platform
specific feature in his feature set unless it's obviously makes sense, like
not support Visual Studio Generator on Linux is just fine.

In the present case, the point of using libarchive is precisely the fact that
the same range of features are available on all CMake-supported platforms.

How would I write a portable CMakeLists.txt and use TXZ if I have not 
"by-design" clue that TXZ will be available on a particular platform?

I can see two options for achieving this:

 1) Create something like cmxzutils (from http://tukaani.org/xz/) and
    ensure it compiles on all CMake supported platform
    Then your patch is ok.

 2) Create a TAR CPack generator (which does not exist yet)
    and authorize this generator to have a CPACK_TAR_POSTPROCESS
    option which could be used to specify a post-processing
    command on the file(s) produced by the TAR generator.

    set(CPACK_TAR_POSTPROCESS "xz;.xz;.txz")

    would mean than xz would be called on the file(s) 
    resulting files would be appended the ".xz" suffix
    in the end it should be renamed .txz.

    This way one could write in its CMakeLists.txt
    find_program(XZ_PROGRAM NAMES xz)
    if (XZ_PROGRAM)
       list(APPEND CPACK_GENERATORS "TAR")
       set(CPACK_TAR_POSTPROCESS "${XZ_PROGRAM};.xz;.txz")
    else (XZ_PROGRAM)
       list(APPEND CPACK_GENERATORS "TBZ2")
    endif(XZ_PROGRAM)

 

---------------------------------------------------------------------- 
 (0029278) Eric NOULARD (developer) - 2012-04-20 20:55
 http://cmake.org/Bug/view.php?id=13072#c29278 
---------------------------------------------------------------------- 
Not working on this until I get feedback from other CMake dev.
Mario you can raise the discussion on cmake developer ML refering
to this if you want to try accelerate this process. 

---------------------------------------------------------------------- 
 (0029816) Shlomi Fish (reporter) - 2012-06-23 16:58
 http://cmake.org/Bug/view.php?id=13072#c29816 
---------------------------------------------------------------------- 
Since I'd also like to have tar.xz functionality in the upstream CMake, I've now
requested feedback from the CMake developer mailing list:

http://public.kitware.com/pipermail/cmake-developers/2012-June/004431.html

Regards,

— Shlomi Fish 

---------------------------------------------------------------------- 
 (0029821) Eric NOULARD (developer) - 2012-06-25 11:21
 http://cmake.org/Bug/view.php?id=13072#c29821 
---------------------------------------------------------------------- 
I think that for portability reason it's not reasonable
to include LZMA unless we can include a portable lzma library
in the CMake source.
I won't have time to do that myself though.

Another solution would be to dynamically check (when running CPack)
that the TXZ generator may run.
This is now possible using
cmCPackXXXGenerator::CanGenerate() interface which was introduced
for dynamically enabling RPM and DEB generator on OS (cf
http://cmake.org/Bug/view.php?id=13064).

The idea behind this is that the CPack generator
may always be compiled with the concerned generator activated
but the factory has a (simple) way to check whether if the generator
is usable or not **at run time**.
If the check is successfull then the generator may be used
(and appear in the cpack --help list) if not the factory
does not build the concerned generator and it does not appear
in the list.

The entry point for that behavior is the
cmCPackGeneratorFactory::cmCPackGeneratorFactory() constructor.
The CPack main program is using an instance of this factory class. 

---------------------------------------------------------------------- 
 (0029822) Eric NOULARD (developer) - 2012-06-25 11:22
 http://cmake.org/Bug/view.php?id=13072#c29822 
---------------------------------------------------------------------- 
Unassigning until we have feedback 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2012-03-29 16:33 Mario Lang     New Issue                                    
2012-03-29 16:33 Mario Lang     File Added:
0001-cmCPackTXZGenerator-Add-tar.xz-archive-generation.patch                    
2012-03-29 16:36 Mario Lang     File Added:
0002-Add-CPACK_BINARY_TXZ-and-CPACK_SOURCE_TXZ-options.patch                    
2012-03-29 16:52 Eric NOULARD   Issue Monitored: Eric NOULARD                   

2012-03-30 17:20 Eric NOULARD   Assigned To               => Eric NOULARD    
2012-03-30 17:20 Eric NOULARD   Status                   new => assigned     
2012-03-30 17:40 Eric NOULARD   Note Added: 0029008                          
2012-03-30 17:43 Eric NOULARD   Assigned To              Eric NOULARD =>     
2012-03-30 17:48 Eric NOULARD   Relationship added       has duplicate 0001104
2012-03-30 17:52 Eric NOULARD   Note Added: 0029010                          
2012-03-30 19:04 Brad King      Relationship added       duplicate of 0011040
2012-03-30 19:05 Brad King      Relationship deleted     has duplicate 0001104
2012-03-30 19:06 Eric NOULARD   Status                   assigned => new     
2012-04-01 09:59 Mario Lang     Note Added: 0029026                          
2012-04-01 10:39 Eric NOULARD   Note Added: 0029027                          
2012-04-01 10:39 Eric NOULARD   Note Edited: 0029027                         
2012-04-20 20:55 Eric NOULARD   Note Added: 0029278                          
2012-04-20 20:55 Eric NOULARD   Assigned To               => Eric NOULARD    
2012-04-20 20:55 Eric NOULARD   Status                   new => feedback     
2012-05-15 19:04 David Faure    Issue Monitored: David Faure                    
2012-06-23 16:58 Shlomi Fish    Note Added: 0029816                          
2012-06-25 11:21 Eric NOULARD   Note Added: 0029821                          
2012-06-25 11:22 Eric NOULARD   Note Added: 0029822                          
2012-06-25 11:22 Eric NOULARD   Status                   feedback => new     
======================================================================




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