Meson support

[pedro-w]

I'd like to discuss the support for the meson build system in vcpkg, for working with a port that uses meson as its primary build system. As far as I can see there are some 'built-in' cmake scripts and also a package vcpkg-tools-meson which overrides some of those scripts. I think adding a dependency on vcpkg-tools-meson allows the user to choose which version of meson runs, whereas the built-in one defaults to 0.58. Is there another reason for having it in two places?

What caught my attention is that the script vcpkg_configure_meson.cmake, which exists in both places but is slightly different in each, has a couple of minor issues. First, it passes the flags --native and --cross to meson even though they are not meson options, and second, the native/cross files it generates are given the extension .log, where .ini seems to be the convention. In fact these things don't cause problems because meson seems to accept any prefix of the actual flags (--native-file and --cross-file) and doesn't care what the file name is. However it would be nice to straighten this out, only because I spent quite a while trying to understand how it was working until I realised about the prefixes and that the .log files weren't log files.

But, I may be missing something about how this is supposed to work! What do people think?

[dg0yt]

Is there another reason for having it in two places?

The "built-in" scripts lack versioning and thus must be more or less frozen in order to not break manifest mode with old port versions.
New ports shall use the script ports which can be improved over time.

the native/cross files it generates are given the extension .log, where .ini seems to be the convention.

The .log extension is treated special in vcpkg CI: These files are put into failure log archives. It is also aplied to some generated cmake files. So no change expected here.

[pedro-w]

That's great, thank you for clarifying @dg0yt

Do you agree that --native should really be --native-file (and likewise for cross)? But, if it works, I suppose it's not worth changing.

[dg0yt]

Do you agree that --native should really be --native-file (and likewise for cross)? But, if it works, I suppose it's not worth changing.

Well, it doesn't seem to need a change now, but it might be something worth checking during the next update to port vpckg-tool-meson.