Minor fixes in common.bzl

[nettle]

Why:
Just fix some minor style inconsistency

What:

• Rename source_attr to SOURCE_ATTR
• Rename old_bazel_attributes to version_specific_attributes
• Format load
• Remove unused code_checker_test rule
• Move and fix warning function
• Replace warning with print in aspect

[Szelethus]

I like all of the changes besides the removal of the warning function. What is the design philosophy behind that change? Personally, I think it is a change for the worse.

If we leave that function in, the rest of the patch LGTM.

[Szelethus]

Please consider restoring warning().

[nettle]

Hi @furtib and @Szelethus,
Sure, I'll get warning() function back.
There were actually 3 reasons to remove it:

1. It is used only in one place (src/per_file.bzl)
2. We do not actually use it, need it, and it should probably replaced by print(). We can discuss.
3. I guess it does not work as it is, please take a look. You may try to convince me in the opposite.

[nettle]

Please consider restoring warning().

Done

[Szelethus]

LGTM

[Szelethus]

Hi @furtib and @Szelethus, Sure, I'll get warning() function back. There were actually 3 reasons to remove it:

1. It is used only in one place (src/per_file.bzl)
2. We do not actually use it, need it, and it should probably replaced by print(). We can discuss.

The intent of the original patch was to start using is later down the line. Also, we have plenty of unmerged PRs, I'm not sure which ones do actually use it.

3. I guess it does not work as it is, please take a look. You may try to convince me in the opposite.

Likewise! I guess that is a discussion-worthy topic; the rest of the changes are trivial.

[Szelethus]

Woops, that slipped through. This was meant to be a warning.