Golangci-lint: structcheck returns false positives, for variables defined in different file, in the same package

[moolibdensplk]

Thank you for creating the issue!

Please include the following information:

1. Version of golangci-lint: golangci-lint --version (or git commit if you don't use binary distribution)

commit: 692dacb773b703162c091c2d8c59f9cd2d6801db (master branch).

1. Config file: cat .golangci.yml

no config, running manually using:
golangci run --disable-all -E structcheck

1. Go environment: go version && go env

$ go version
go version go1.12.4 darwin/amd64

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/REDACTED/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/REDACTED/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/Cellar/go/1.12.4/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.12.4/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="0"
GOMOD="/Users/REDACTED/cloud/REDACTED/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/yq/bwmkdmt135q2565hzm6qy57c0000gn/T/go-build639278964=/tmp/go-build -gno-record-gcc-switches -fno-common"

1. Verbose output of running: golangci-lint run -v

$ golangci-lint run -v --disable-all -E structcheck
INFO [config_reader] Config search paths: [./ /Users/REDACTED/cloud/REDACTED /Users/REDACTED/cloud /Users/REDACTED /Users /]
INFO [config_reader] Used config file .golangci.yml
INFO [lintersdb] Active 1 linters: [structcheck]
INFO [loader] Go packages loading at mode load types and syntax took 1.36938593s
INFO [loader] SSA repr building timing: packages building 20.752897ms, total 439.769658ms
INFO [runner] worker.8 took 2.787µs
INFO [runner] worker.12 took 2.049µs
INFO [runner] worker.3 took 685ns
INFO [runner] worker.5 took 1.272µs
INFO [runner] worker.1 took 1.935µs
INFO [runner] worker.4 took 782ns
INFO [runner] worker.2 took 1.328µs
INFO [runner] worker.9 took 1.218µs
INFO [runner] worker.6 took 1.885µs
INFO [runner] worker.11 took 1.732µs
INFO [runner] worker.10 took 2.2µs
INFO [runner] worker.7 took 2.913397ms with stages: structcheck: 2.90531ms
INFO [runner] Workers idle times: #1: 2.812024ms, #2: 2.799165ms, #3: 2.83959ms, #4: 2.794031ms, #5: 2.821053ms, #6: 2.768656ms, #8: 2.874194ms, #9: 2.78048ms, #10: 2.733417ms, #11: 2.73826ms, #12: 2.849321ms
INFO [runner] processing took 897.568µs with stages: identifier_marker: 233.772µs, skip_dirs: 232.073µs, exclude: 187.111µs, source_code: 95.93µs, autogenerated_exclude: 53.575µs, cgo: 23.62µs, nolint: 21.673µs, path_prettifier: 12.031µs, max_same_issues: 11.942µs, uniq_by_line: 7.61µs, filename_unadjuster: 4.097µs, max_from_linter: 4.093µs, max_per_file_from_linter: 3.4µs, replacement_builder: 3.133µs, path_shortener: 2.899µs, diff: 254ns, skip_files: 191ns, exclude-rules: 164ns

[...]
internal/definitions.go:154:2: `lfTf` is unused (structcheck)
    lfTf              *lockfile.Lockfile 
    ^
internal/definitions.go:156:2: `lpId` is unused (structcheck)
    lpId              string
    ^
[....]
INFO File cache stats: 1 entries of total size 6.5KiB
INFO Memory: 21 samples, avg is 309.9MB, max is 675.7MB
INFO Execution took 1.923498231s

The problem happens when the given variables / types are defined in one file, and used in another in the same package.

I did a quick test to asses whether these were really unused, and here is the logic:
a. I took one of these, reported as unused:

internal/definitions.go:154:2: `lfTf` is unused (structcheck)
    lfTf              *lockfile.Lockfile 
    ^

b. commented it out in the file where it is defined
c. ran the linter again:
As expected, that returned errors about lfTf being undeclared:

$ golangci-lint run -E structcheck
internal/module1.go:376:20: mod1cfg.lfTf undefined (type SomeType has no field or method lfTf) (typecheck)
    unlockFile(mod1cfg.lfTf)
                      ^
internal/module2go:852:20: mod2cfg.lfTf undefined (type SomeType has no field or method lfTf) (typecheck)
    unlockFile(mod2cfg.lfTf)
                      ^
internal/module3.go:228:20: mod3cfg.lfTf undefined (type  SomeType no field or method lfTf) (typecheck)
    unlockFile(blahcfg.lfTf)

I was able to recreate the issue for all of the objects reported by first check.
I noticed that megacheck used to have a similar problem and that you guys have fixed it previously:
https://github.com/golangci/golangci-lint/issues/148

Would you mind looking at structcheck as well ?
Cause at the moment, I had to disable this linter in our pipeline, as it turns out all errors coming from it, happen to be false positive in our scenario (where we have some structure definitions in one file, that are then used in different files within the same package).

Kind regerads
moolibdensplk

[arthurkiller]

same with me

[parvathi-nair]

Would there be a fix soon? In My case, it is not a different file, but the variables are used from two different structs like this . A { name string } B{ A, age int}, C{A , color string}. Both B and C use A which uses name. But the golangci says name is not used.

[Charliekenney23]

I've found this to happen when using files with periods in the name with as recent as v1.23.6

I changed a file add.test.go to add_test.go and the package-level variables were resolved.

[h4yfans]

Still same with me