pkg/cover: allow paths to be excluded from stats

[quic-likaid]

Some sub paths may not be covered due to hardware configuration, or lack of interest. This patch allows them to be excluded from the stats. This can be convenient if the excluded paths are deep in the hierarchy:

{
    "name": "sound",
    "path": [
	"techpack/audio",
	"-techpack/audio/asoc/aaa/bbb"
	"-techpack/audio/asoc/aaa/ccc"
    ]
}

---

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https://github.com/google/syzkaller/blob/master/docs/contributing.md

---

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[tarasmadan]

Hi quic-likaid.
Do you plan to use it locally only?

I'd like to better understand your motivation.

[quic-likaid]

Hi @tarasmadan ,

We have a lot of modules enabled on an arm64 target , but only some of them are reachable due to hardware configuration.

If we have following paths:

techpack/audio
techpack/audio/asoc/a/1
techpack/audio/asoc/a/2
techpack/audio/asoc/a/3
techpack/audio/asoc/a/4
techpack/audio/asoc/a/5
techpack/audio/dsp

Say we want to exclude a/1 and a/2, before this patch the config is

"path": [
  "techpack/audio/asoc/a/3",
  "techpack/audio/asoc/a/4",
  "techpack/audio/asoc/a/5",
  "techpack/audio/dsp"
]

With the patch it becomes:

"path": [
  "techpack/audio",
  "-techpack/audio/asoc/a/1",
  "-techpack/audio/asoc/a/2"
]

which is hopefully clearer.

[quic-likaid]

re-created the commit to trigger CLA check. (failed again..)

[tarasmadan]

Does it mean you have your own, manually crafted subsystem definitions and you want to have more flexible syntax to describe them?

[quic-likaid]

Does it mean you have your own, manually crafted subsystem definitions and you want to have more flexible syntax to describe them?

Yes.

[a-nogikh]

@jiangenj did you mean to push all those commits here or was it by mistake?

[jiangenj]

@jiangenj did you mean to push all those commits here or was it by mistake?

Thanks, it's by mistake.

[jiangenj]

@quic-likaid still facing with the cla/google issue, perhaps it's your account setting.

[tarasmadan]

Do you plan to test it?

[quic-likaid]

Do you plan to test it?

I did look at the existing tests before committing. It seems to me that the test (report_test.go) could not be easily extended to cover the change. It only has a dummy main function.

I'm using the change in our internal setup, and it works fine.

[quic-likaid]

Added a new test.

[quic-likaid]

Hi @tarasmadan , I've resolved a merge conflict. Would you please review? Thanks.