golint: exported func returns unexported type *package._Ctype_char, which can be annoying to use

[adambabik]

Thank you for creating the issue!

• Yes, I'm using a binary release within 2 latest major releases. Only such installations are supported.
• Yes, I've searched similar issues on GitHub and didn't find any.
• Yes, I've included all information below (version, config, etc).

The problem is with golint and returning C types in CGO files. In previous versions of golangci-lint, it was not a problem.

The example I reproduce the problem looks like this:

package main

// #include <stdlib.h>
import "C"
import "fmt"

// SomeFunction blah blah blah.
//export
func SomeFunction() *C.char {
	return C.CString("some string")
}

func main() {
	fmt.Println(C.GoString(SomeFunction()))
}

I also installed golint and run it on the same package with the code from above:

$ go get -u golang.org/x/lint/golint
$ golint ./testc/...
# no errors

Please include the following information:

Version of golangci-lint

$ golangci-lint --version
golangci-lint has version 1.21.0 built from 645e794 on 2019-10-15T18:15:04Z

Config file

$ cat .golangci.yml
run:
  concurrency: 4
  deadline: 1m
  issues-exit-code: 1
  tests: true
  skip-dirs:
    - static

output:
  format: colored-line-number
  print-issued-lines: true
  print-linter-name: true

linters-settings:
  errcheck:
    check-type-assertions: false
    check-blank: false
  govet:
    check-shadowing: false
  golint:
    min-confidence: 0.8
  gofmt:
    simplify: true
  gocyclo:
    min-complexity: 16
  maligned:
    suggest-new: true
  dupl:
    threshold: 50
  goconst:
    min-len: 3
    min-occurrences: 2

linters:
  disable-all: true
  enable:
    - deadcode
    - errcheck
    - gosec
    - goconst
    - gocyclo
    - gofmt
    - golint
    - gosimple
    - govet
    - ineffassign
    - misspell
    - staticcheck
    - structcheck
    - typecheck
    - unconvert
    - varcheck
    - unused
  fast: false

issues:
  exclude:
    - "composite literal uses unkeyed fields" # govet
    - "G304: Potential file inclusion via variable" # gosec
    - "G104: Errors unhandled." #gosec

Go environment

$ go version && go env
go version go1.13 darwin/amd64
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/adamb/Library/Caches/go-build"
GOENV="/Users/adamb/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/adamb/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.13/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.13/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/adamb/repos/status-go/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 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/g2/km2y9qqj4bbf329f2bt1xqc80000gn/T/go-build712926417=/tmp/go-build -gno-record-gcc-switches -fno-common"

Verbose output of running

$ golangci-lint run -v
INFO [config_reader] Config search paths: [./ /Users/adamb/repos/status-go/testc /Users/adamb/repos/status-go /Users/adamb/repos /Users/adamb /Users /]
INFO [config_reader] Used config file .golangci.yml
INFO [lintersdb] Active 17 linters: [deadcode errcheck goconst gocyclo gofmt golint gosec gosimple govet ineffassign misspell staticcheck structcheck typecheck unconvert unused varcheck]
INFO [loader] Go packages loading at mode 575 (compiled_files|exports_file|files|types_sizes|deps|imports|name) took 255.943424ms
INFO [runner/filename_unadjuster] Pre-built 0 adjustments in 495.881µs
INFO [runner/goanalysis_metalinter/goanalysis] analyzers took 0s with no stages
INFO [runner/unused/goanalysis] analyzers took 0s with no stages
INFO [runner] Issues before processing: 38, after processing: 1
INFO [runner] Processors filtering stat (out/in): source_code: 1/1, autogenerated_exclude: 2/2, identifier_marker: 2/2, exclude-rules: 1/1, max_per_file_from_linter: 1/1, skip_dirs: 2/2, max_same_issues: 1/1, max_from_linter: 1/1, filename_unadjuster: 2/2, skip_files: 2/2, uniq_by_line: 1/1, diff: 1/1, path_shortener: 1/1, cgo: 2/38, path_prettifier: 2/2, exclude: 1/2, nolint: 1/1
INFO [runner] processing took 1.959982ms with stages: exclude: 1.223534ms, nolint: 292.979µs, source_code: 139.55µs, path_prettifier: 114.731µs, identifier_marker: 84.568µs, autogenerated_exclude: 49.163µs, skip_files: 15.302µs, skip_dirs: 14.817µs, cgo: 6.053µs, uniq_by_line: 5.325µs, max_same_issues: 4.188µs, max_from_linter: 3.009µs, filename_unadjuster: 2.76µs, path_shortener: 2.364µs, max_per_file_from_linter: 773ns, diff: 474ns, exclude-rules: 392ns
INFO [runner] linters took 48.948762ms with stages: goanalysis_metalinter: 46.141564ms, unused: 526.612µs
testc/main.go:8:21: exported func SomeFunction returns unexported type *github.com/status-im/status-go/testc._Ctype_char, which can be annoying to use (golint)
func SomeFunction() *C.char {
                    ^
INFO File cache stats: 1 entries of total size 182B
INFO Memory: 5 samples, avg is 68.7MB, max is 68.7MB
INFO Execution took 325.296482ms

[jiacai2050]

Anyone working on this issue?

[ernado]

You can ignore it via exclude-rules as a workaround.

Probably we should update golint to latest version and it will auto-resolve.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.