[bugfix] Fix hook override with multiple inheritance

[jjotero]

This PR rearranges the instantiation/construction process of classes using the RegressionTestMeta metaclass. The RegressionTestMeta is now agnostic of pipeline-specific concepts, which facilitates its use in other classes which could also benefit from using all the machinery implemented in this metaclass (such as the BuildSystem - see #2030):

• variables and parameters are now injected into a class from the __call__ method in the metaclass, instead of the __new__ method from the class. This means that now any class that uses this RegressionTestMeta can use the variables and parameters "for free" without implementing anything else.
• The injection and stage-specific mapping of hooks now happens in the __new__ method of the RegressionTest class. This moves all pipeline-specific concepts into the pipeline itself. This rearrangement paves the way for Dynamic pipeline stages #1936, and for the same money, it closes Incomplete hook override with multiple inheritance #2055.

[codecov-commenter]

Codecov Report

Merging #2081 (b7e70d8) into master (13af717) will increase coverage by 0.00%.
The diff coverage is 98.64%.

@@           Coverage Diff           @@
##           master    #2081   +/-   ##
=======================================
  Coverage   86.74%   86.75%           
=======================================
  Files          52       52           
  Lines        9267     9272    +5     
=======================================
+ Hits         8039     8044    +5     
  Misses       1228     1228           

Impacted Files	Coverage Δ
reframe/core/hooks.py	90.21% <94.11%> (-0.70%)	⬇️
reframe/core/meta.py	98.92% <100.00%> (-0.07%)	⬇️
reframe/core/pipeline.py	91.73% <100.00%> (+0.33%)	⬆️

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[vkarak]

Lgtm except a couple of minor comments + the following one. Since now the hooks are checked upon class instantiation, if somebody tries to attach a hook to an inexistent state, they get:

./bin/reframe: skipping test 'HelloTest' due to errors: use `-v' for more information
    FILE: n/a:n/a

The first part of the message, I think should be addressed by #1899, but the second one might be related to this PR. If not, we address that in #1899 as well.

[vkarak]

I check the error message in master:

./bin/reframe: run session stopped: value error: ../misc/rfm-support/issue-1899/hello1.py:16: invalid pipeline stage specified: 'foo'
    @run_before('foo')

[vkarak]

You can ignore the comments about the error message here. They will be fixed by #2087.

[pep8speaks]

Hello @jjotero, Thank you for updating!

Cheers! There are no PEP8 issues in this Pull Request!Do see the ReFrame Coding Style Guide

Comment last updated at 2021-07-23 13:42:46 UTC

[vkarak]

Just a final minor comment.

[vkarak]

lgtm