RFC: plan for starting the Qt5/KF5 port

[Jaroslaw Staniek]

On 24 February 2015 at 03:55, Friedrich W. H. Kossebau <kossebau at kde.org> wrote:
> Hi,
>
> rough plan was to start porting after the 2.9 release. Whose dates are:
>
> Tagging February 24nd (moved from 22nd)
> Release February 26th
>
> To get some patches in that do not fit for the 2.9 branch and otherwise would
> bitrot due to the Qt5/KF5 port, there will be a merge window for master.
> Everyone having some WIP stuff that is good enough for merging, brush it up
> now and get it in!
>
> "Merge window for master" until: Wed March 4th (proposed)
> "Porting start": same day of merge window close
>
> Porting branch named "frameworks" usually, some stuff expects it even.
>
> Initial porting steps (done by 1 person):
> -----------------------------------------
> 1. Merge "calligra/2.9" another time into "master"
> 2. Branch off "frameworks" from "master"
> 3. Apply https://git.reviewboard.kde.org/r/121541/
> 4. Remove these subdirs:
>    3rdparty/kdchart/
>    3rdparty/kdchartpatches/
>    3rdparty/kdgantt/
>    3rdparty/kdganttpatches/
>    libs/koproperty/
>    libs/koreport/
>    (anything else moved outside?)

At least:
plugins/reporting/
libs/db/
some of cmake/modules/* (discussed yesterday with me)

> 5. Port just the buildsystem to Qt5/KF5/ECM as much as needed to get "cmake"
> configure pass and "make" && "make install" also pass with success, without
> porting any code (should be all disabled still by step 3).
> 6. Create commit and push "frameworks" branch to central Calligra repo
> 7. Request a build on KDE CI for the "frameworks" branch
> 8. Take disabled product from end of product dep tree* and make it build:
>    1. remove "UNPORTED" tag
>    2. port it as much as needed to make it build
>    3. commit to "frameworks" branch
> 9. if LIB_CALLIGRA has been added to the build, tell everyone to join
>    goto 8. until there is no more "UNPORTED" tag
>
> *The dep tree of products can be either seen from content of
> CalligraProducts.cmake or in a picture by using the generated
> "product_deps.dot" in the toplevel dir:
> dot -Tsvg product_deps.dot > product_deps.svg
> or
> dot -Tpng product_deps.dot > product_deps.png
>
> Porting Rules (proposed):
> -------------------------
> * do not port away from kdelibs4support initally, but see to get it added to
> the build as quickly as possible (only then go perhaps further)
> * ensure CI always manages to build (to ease life of co-porters)
> * love to the tests
> * anything that needs temporarily to be disabled by commenting out should get
>   a tag "QT5TODO" (anything better?), so it will not be forgotton before 3.0
>

A candy to users of Qt Creator: http://i.imgur.com/4Rz0W0T.png
Any set of tags can be configured. Feel free to append invent tags
like KRITA3 or KRITAQT5.
So you can filter the tags easier in your area of interest, make the code
navigation easier.
I am sure vim/emacs users have their habits and the tags can work for
them as well.

> Reasoning:
> ----------
> Calligra has over 4 M lines (claims openhub.net, not counted myself), so
> expecting one person to do all the initial porting would be quite some burden
> to that. Also is noone expert in all code.
> The proposed UNPORTED tag system (see step 3. above) and the initial porting
> product-by-product as much as needed to get it build at least should help to
> parallelize the work quickly, so everyone can give special love to the code
> they care for.
> Sadly krita is not "product"ed, so there it will be more a matter of control
> by commenting in CMakeLists.txt. Surely also doable :)
>
> To not have people step on each other toes and do conflicting work, I will add
> a wiki page where people can "take" a product before they start working on
> making it build (and where I possibly should also dump this plan).
> Any proposal for the location and name of the wiki page below
> community.kde.org/Calligra ?

Wiki tables unless heavily splited to sections are barely interactive.
Unfortunately (because Kexi should be used for that in the cloud) I
have to propose a Google docs spreadsheet for real time editing of
what's done, what's a TODO.

> On #kde-devel the recommendation was to not blindly run any porting scripts
> that are available, but rather decide case-by-case if to run the script or
> just do manual porting. Another reason why splitting the porting work into
> different people makes more sense.

A rule I propose: always mention in a commit message the what script
was used and have one commit per run (exception: trivial changes).

> I expect different parts of Calligra to go different miles for 3.0. Some might
> port away from kdelibs4support as there is not a lot to do, some might be
> happily using it for 3.0. Both should be very fine.
> Important are as few regressions as possible and something that is usable :)
>
> Comments, please.

Looks good but I am before my coffee...

> PS: Tomas, you had done some initial buildsystem porting experients, right?
> Would you be willing to be the person to do the initial porting steps?

PS: in what time zone are you at the moment? :)

-- 
regards, Jaroslaw Staniek

KDE:
: A world-wide network of software engineers, artists, writers, translators
: and facilitators committed to Free Software development - http://kde.org
Calligra Suite:
: A graphic art and office suite - http://calligra.org
Kexi:
: A visual database apps builder - http://calligra.org/kexi
Qt Certified Specialist:
: http://www.linkedin.com/in/jstaniek