"Andrei Alexandrescu" <seewebsiteforem...@erdani.org> wrote in message news:it7pd2$2m07$1...@digitalmars.com... > http://www.wikiservice.at/d/wiki.cgi?LanguageDevel/DIPs/DIP11 > > Destroy. >
After all that talk about how we need to be very cautious about adding new features to the compiler and work with the existing language whenever possible, only a few days later now we're seriously considering adding an entire *build system* to the compiler? And let's not fool ourselves: in order for this not to be half-baked, it would have to completely take over all the roles handled by a full-featured build-and-package-management system. Just off the top of my head: - Putting it in the compiler forces it all to be written in C++. As an external tool, we could use D. - By default, it ends up downloading an entire library one inferred source file at a time. Why? Libraries are a packaged whole. Standard behavior should be for libraries should be treated as such. - Are we abandoning zdmd now? (Or is it "dmdz"?) - Does it automatically *compile* the files it downloads or merely use them to satisfy imports? If the latter, then the whole proposal becomes pointless - you'll just need to tie it in with RDMD anyway, so you may as well just keep it outside the compiler. If the former, then you're implicitly having DMD creep into RDMD's territory - So either be explicit about it and take it all the way putting all of rdmd into there, or get rid of it and let the build tools handle package-management matters. - Does every project that uses libX have to download it separately? If not (or really even if so), how does the compiler handle different versions of the lib and prevent "dll hell"? Versioning seems to be an afterthought in this DIP - and that's a guaranteed way to eventually find yourself in dll hell. - How do you tell it to "update libX"? Not by expecting the user to manually clear the cache, I hope. - With a *real* package management tool, you'd have a built-in (and configurable) list of central data sources. If you want to use something you don't have installed, and it exists in one of the stores (maybe even one of the built-in ones), you don't have to edit *ANYTHING AT ALL*. It'll just grab it, no changes to your source needed at all, and any custom steps needed would be automatically handled. And if it was only in a data store that you didn't already have in your list, all you have to do is add *one* line. Which is just as easy as the DIP, but that *one* step will also suffice for any other project that needs libX - no need to add the line for *each* of your libX-using projects. Heck, you wouldn't even need to edit a file, just do "package-tool addsource http://...";. The DIP doesn't even remotely compare. - I think you're severely overestimating the amount of extra dmd-invokations that would be needed by using an external build tool. I beleive this is because your idea centers around discovering one file at a time instead of properly handling packages at the *package* level. Consider this: You tell BuildToolX to build MyApp. It looks at MyApp.config to see what libs it needs. It discovers LibX is needed. It fetches LibX.config, and finds it's dependencies. Etc, building up a dependency graph. It checks for any problems with the dependency graph before doing any real work (something the DIP can't do). Then it downloads the libs, and *maybe* runs some custom setup on each one. If the libs don't have any custom setup, you only have *one* DMD invokation (two if you use RDMD). If the libs do have any custom setup, and it involves running dmd, then that *only* happens the first time you build MyApp (until you update one of the libs, causing it's one-time setup to run once more). I think this proposal is a hasty idea that just amounts to chasing after "the easy way out".
