Some reports are "randomly" missing

[ldez]

Describe the bug

Some reports are "randomly" missing

To Reproduce

git clone -q git@github.com:prometheus/prometheus.git
cd prometheus
git checkout 701d13abf

$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
720
$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
720
$ revive ./... | wc -l
723
...

As you can see, sometimes there are 723 reports and sometimes there are only 720 reports.

Expected behavior

Report consistency.

Additional context

For now, I didn't find the root cause but I think the problem is related to a concurrency issue.
I will try to find the root cause.

[denisvmedia]

Maybe compiling it with -race option can help?

[ldez]

The run (not the compilation) is at least 4 times slower.

 revive ./... | wc -l
==================
WARNING: DATA RACE
Write at 0x00c000e14020 by goroutine 231:
  github.com/mgechev/revive/lint.(*Package).TypeCheck()
      /home/ldez/sources/golangci-lint-linters/revive/lint/package.go:132 +0x833
  github.com/mgechev/revive/rule.(*TimeNamingRule).Apply()
      /home/ldez/sources/golangci-lint-linters/revive/rule/time_naming.go:25 +0x164
  github.com/mgechev/revive/lint.(*File).lint()
      /home/ldez/sources/golangci-lint-linters/revive/lint/file.go:109 +0x286
  github.com/mgechev/revive/lint.(*Package).lint.func1()
      /home/ldez/sources/golangci-lint-linters/revive/lint/package.go:196 +0x10b
  golang.org/x/sync/errgroup.(*Group).Go.func1()
      /home/ldez/sources/go/pkg/mod/golang.org/x/sync@v0.12.0/errgroup/errgroup.go:78 +0x91

Previous read at 0x00c000e14020 by goroutine 230:
  github.com/mgechev/revive/lint.(*Package).TypeOf()
      /home/ldez/sources/golangci-lint-linters/revive/lint/package.go:153 +0x75a
  github.com/mgechev/revive/rule.(*UnexportedReturnRule).Apply()
      /home/ldez/sources/golangci-lint-linters/revive/rule/unexported_return.go:44 +0x6e9
  github.com/mgechev/revive/lint.(*File).lint()
      /home/ldez/sources/golangci-lint-linters/revive/lint/file.go:109 +0x286
  github.com/mgechev/revive/lint.(*Package).lint.func1()
      /home/ldez/sources/golangci-lint-linters/revive/lint/package.go:196 +0x10b
  golang.org/x/sync/errgroup.(*Group).Go.func1()
      /home/ldez/sources/go/pkg/mod/golang.org/x/sync@v0.12.0/errgroup/errgroup.go:78 +0x91

Goroutine 231 (running) created at:
  golang.org/x/sync/errgroup.(*Group).Go()
      /home/ldez/sources/go/pkg/mod/golang.org/x/sync@v0.12.0/errgroup/errgroup.go:75 +0x124
  github.com/mgechev/revive/lint.(*Package).lint()
      /home/ldez/sources/golangci-lint-linters/revive/lint/package.go:195 +0x11a
  github.com/mgechev/revive/lint.(*Linter).lintPackage()
      /home/ldez/sources/golangci-lint-linters/revive/lint/linter.go:156 +0x557
  github.com/mgechev/revive/lint.(*Linter).Lint.func1()
      /home/ldez/sources/golangci-lint-linters/revive/lint/linter.go:107 +0x24b
  golang.org/x/sync/errgroup.(*Group).Go.func1()
      /home/ldez/sources/go/pkg/mod/golang.org/x/sync@v0.12.0/errgroup/errgroup.go:78 +0x91

Goroutine 230 (running) created at:
  golang.org/x/sync/errgroup.(*Group).Go()
      /home/ldez/sources/go/pkg/mod/golang.org/x/sync@v0.12.0/errgroup/errgroup.go:75 +0x124
  github.com/mgechev/revive/lint.(*Package).lint()
      /home/ldez/sources/golangci-lint-linters/revive/lint/package.go:195 +0x11a
  github.com/mgechev/revive/lint.(*Linter).lintPackage()
      /home/ldez/sources/golangci-lint-linters/revive/lint/linter.go:156 +0x557
  github.com/mgechev/revive/lint.(*Linter).Lint.func1()
      /home/ldez/sources/golangci-lint-linters/revive/lint/linter.go:107 +0x24b
  golang.org/x/sync/errgroup.(*Group).Go.func1()
      /home/ldez/sources/go/pkg/mod/golang.org/x/sync@v0.12.0/errgroup/errgroup.go:78 +0x91
==================
Found 1 data race(s)
720

[ldez]

The problem is related to the modification of the structure Package inside the method Package.TypeCheck.

Same root cause as #1277

[ldez]

🤔 I think I know how to fix that.

Better, but still not right:

$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
722
$ revive ./... | wc -l
723
$ revive ./... | wc -l
723
$ revive ./... | wc -l
721

And sadly, with my change, the race detector found nothing.

[denisvmedia]

The run (not the compilation) is at least 4 times slower.

Yeah, that's expected, it's not recommended for production anyway. Does it still produce race condition issues even with your change?

[ldez]

#1307

[ldez]

The PR removes the race condition, but the problem is still here. I will try to understand where the problem is.

[ldez]

I found the problem 🎉

I will run several 1000 run cycles to be sure, but I'm confident.

Note: I found the problem, but there is bad news behind it.