Hey all, for context please see [1] and [2].
[1]: https://bugs.kde.org/show_bug.cgi?id=460245 [2]: https://discourse.cmake.org/t/feature-request-add-custom-command-all/7609 The gist is that me and Igor are annoyed by `ki18n_install` abusing `add_custom_target`, which makes the build always dirty. I.e. every time we run `ninja` we will, at the very least, run the two mo & ts generation targets. For kdevelop, these do non-trivial amounts of work that takes time even on a beefy laptop: ``` $ ninja && time ninja [2/2] Generating mo... [2/2] Generating mo... real 0m1,780s user 0m5,742s sys 0m2,327s ``` I would like to fix this, but first want to get feedback from the KDE developers at large. First of all: Are all projects using ki18n_install in the way we do? Why is no-one else complaining about this so far? Are your po files so small that this doesn't take a significant amount of time? Or are there potentially just so few of them in your project? KDevelop is heavily plugin based which means we have tons of po files. 2464 *.po files to be exact... Secondly: does anyone know how to best approach a solution to this issue? The problem is that I don't see an easy way to solve it: While Kyle Edwards was nice enough to show me a way to tell CMake to not make the custom target always-dirty, `k18n_install` suffers from another design deficiency: It uses globbing internally and has an undefined amount of inputs and outputs, which basically makes it impossible for us to leverage `add_custom_command(OUTPUT` here, or? As such, it seems like one would need a different approach to this problem anyways. Globbing is a known-evil in cmake land, and I would personally prefer to have the inputs explicitly listed, just like we do for source files etc. Because we have many languages though, listing all possible *.po or *.ts files is cumbersome. Instead, what about we maintain the list of known languages in the ki18n framework? Then we could have something like ``` ki18n_target( # the target for which we are handling messages TARGET KF5I18n # the translation domain, added as compile_options and to find files TRANSLATION_DOMAIN ki18n5 # the root po folder location, to look for the .po/.js files PO_FOLDER ${KI18n_SOURCE_DIR}/po ) ``` Internally, this would do what is currently done manually: ``` target_compile_options(KF5I18n PRIVATE -DTRANSLATION_DOMAIN=\"ki18n5\") ``` Then it would iterate over the list of known languages and try to find the .po or .js file. For every match, we would add_custom_target to generate the corresponding .mo/.ts file and add the reverse dependency. What do others say to this approach? Thanks -- Milian Wolff http://milianw.de