On Monday, 16 January 2023 04:49:23 PST Friedemann Kleint via Development wrote: >>>>> Summmarising: we stand to gain a speed-up of compilation; >>>>> particularly for clean builds like in COIN; but it requires some >>>>> work. We might do a step-by step approach process enabling modules >>>>> one by one. What do you think?
On 17.01.23 05:09, Thiago Macieira wrote: >>>> I was going to object to it being in COIN, but considering it may >>>> improve build times in the CI, especially for constrained platforms >>>> (like macOS), I withdraw my objection before I even make it. I >>>> think this effort is worth it. Christian Tismer-Sperling (17 January 2023 11:55) asked: >>> What was the reason that you first considered to object to it? On 17 Jan 2023, at 13:35, Edward Welbourne via Development <development@qt-project.org> wrote: >> While I can't be sure what Thiago was thinking of, one obvious >> objection to doing this in Coin would be that: if someone changes a >> source file in a way that needs a #include addition to the changed >> source file, but Coin's Unity build combines that file with one that >> has the #include, Coin won't notice, the change will get integrated >> and those doing a non-Unity builds, or for whom the Unity build >> splits files up differently, may find themselves with broken builds. >> I imagine there are other mistakes that can likewise be concealed by >> a Unity build. Volker Hilsheimer (17 January 2023 16:26) replied: > I would actually turn Thiago’s objection on its head and ask that we > have at least one configuration in COIN that verifies that > UNITY_BUILDs work, if we agree that this is a good idea. That's more or less the conclusion I understood Thaigo to have reached, too. > In the short term I don’t expect that this will improve effective CI > performance considerably, at least not until every CI configuration > uses UNITY_BUILDs. The spread of build times in > e.g. https://testresults.qt.io/coin/integration/qt/qtbase/tasks/1681530493 > is wild (from a few minutes to almost 1.5hours). No idea why > windows-11_22h2-mingw11-developer-build is so slow, but in the end, > the slowest platform for building and testing defines the time we have > to wait until we know that our changes were good (failing build or > test shortcuts that, of course). That rather suggests making the slower builders use Unity while keeping the fastest build of each platform a traditional build. Then we test that both types work while improving Coin's build speeds. Eddy. _______________________________________________ Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
