Print build info used when using godot --build-info

[Anutrix]

Print build arguments used when using godot --version.
I couldn't find how official builds are generated without hashes so that part is still not done.

Bugsquad edit: This partially addresses #28617.

[Anutrix]

Force-pushed after using black -l 120 SConstruct to format SConstruct.
This doesn't seem to be documented anywhere in the docs yet.

[YuriSizov]

Force-pushed after using black -l 120 SConstruct to format SConstruct.
This doesn't seem to be documented anywhere in the docs yet.

Well, code style contributing guide mentions using pre-commit hooks, but doesn’t list the new ones explicitly.

https://docs.godotengine.org/en/stable/community/contributing/code_style_guidelines.html#pre-commit-hook

[Calinou]

Note that this won't list arguments that were specified in custom.py and in the SCONS_FLAGS environment variable. For SCONS_FLAGS, we can prepend its contents to the sys.argv[1:] line. As for custom.py, it's more difficult as it's a full-fledged Python script.

Also, some arguments such as progress=no or -j8 are probably not worth mentioning in the list of build flags. Still, I think the current implementation in this PR is better than nothing, so it's not blocking either.

[Anutrix]

Another way to do this was by using SCons's ARGUMENTS dictionary but that doesn't include arguments like -j5. Not sure if it includes flags from custom.py but my guess is that it doesn't.

[Xrayez]

Note that you can look at .scons_env.json to have an overview of what kind of parameters were used during a build (build-time over run-time), just to eliminate XY problems for some people.

[Anutrix]

.scons_env.json seems to have too much data which is why I didn't touch it.

[Xrayez]

I believe you could also add some essential build arguments to this first, so they cannot go ignored (many have just defaults), and append the rest of the build arguments from any other source, including sys.argv (you might need to make sure that those arguments are unique).

[akien-mga]

IMO just hardcoding builds args is not so useful per se. I'd prefer an approach that gives the value of some key build options like tools, target, lto, etc. (and then additionally and line args, why not, but we indeed don't care about args that only impact the build host like -j4 or verbose - what matters is what makes the binary different from another one). I'd put this behind a --build-info flag.

[Anutrix]

1st option:
sys.argv[1:]

2nd option:
We can use SCons's ARGUMENTS dictionary which doesn't include -j3 argument.

3rd option:
.scons_env.json has all the build flags. Even if we just consider the exposed commands we get L397-L505. These 109 flags include 55 module_*_enabled flags, 24 builtin_* flags and 30 other flags among which ANDROID_NDK_ROOT is one flag that can be safely ignored.
Assuming we include everything above, we can reduce it to 31(30-1+One super long line with enabled modules+One long line with builtins used) lines.

We would need to manually remove progress, verbose and any empty arguments.
Additionally, irrespective of any of these options chosen, we can remove any flags that have the default values from the result but that would make their output pretty much the same.

Not sure which option would be best.

[aaronfranke]

@Anutrix Is this still desired? If so, it needs to be rebased and tested on the latest master branch.

[Anutrix]

I'm not sure if this is still needed. If I get a response in some time I'll rebase it. We can close it if noone's interested.

[Anutrix]

Rebased and tested on master.
It shows the build args and SCONSFLAGS environment variable.

It can be improved as it doesn't support custom.py or even list out default values but it should be helpful till those are implemented in the future.

[Calinou]

The --build-info command line argument should be listed in the command line help (main/main.cpp). It should also be listed in the Bash, zsh and fish shell completion files (misc/dist/shell/). See #59153 Files changed tab for an example of doing this.

[Calinou]

I tested this PR rebased on master, it seems to work:

❯ bin/godot.linuxbsd.tools.64.llvm --build-info
4.0.alpha.custom_build.bd77c981a
Build arguments: platform=linuxbsd use_llvm=yes LINKFLAGS=-fuse-ld=mold -j10 tests=no

It might be worth looking into stripping the -j command line argument (and the number immediately after it), so that it's not included in the BUILD_ARGUMENTS constant as it's not relevant. This is not critical for an initial implementation still, as this can still be useful for troubleshooting (and distinguishing your own custom builds, similar to #59247).

[akien-mga]

I still think this is a bad idea with the current implementation. It needs to expose the actual configuration used, not which command line parameters were passed:

IMO just hardcoding builds args is not so useful per se. I'd prefer an approach that gives the value of some key build options like tools, target, lto, etc. (and then additionally and line args, why not, but we indeed don't care about args that only impact the build host like -j4 or verbose - what matters is what makes the binary different from another one).

[Anutrix]

Closing it so that someone can work on better and cleaner version.

(Maybe someone/new contributors can use this as a simple reference.)