nlreturn false positives when using cgo

[emm1R]

Welcome

• Yes, I'm using a binary release within 2 latest releases. Only such installations are supported.
• Yes, I've searched similar issues on GitHub and didn't find any.
• Yes, I've read the typecheck section of the FAQ.
• Yes, I've tried with the standalone linter if available (e.g., gocritic, go vet, etc.).
• I agree to follow this project's Code of Conduct

How did you install golangci-lint?

Brew

Description of the problem

When using cgo, I receive false positives from nlreturn. It is saying return with no blank line before for lines with defer or return when these lines call C functions. Adding a newline does not remove the issue. The problem with return lines does not happen always, and I was unable to replicate it in the example.

Version of golangci-lint

$ golangci-lint --version
golangci-lint has version 2.0.2 built with go1.24.1 from 2b224c2c on 2025-03-25T21:36:18Z

Configuration

-E nlreturn

Go environment

$ go version && go env
go version go1.24.0 darwin/arm64
AR='ar'
CC='clang'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='clang++'
GCCGO='gccgo'
GO111MODULE=''
GOARCH='arm64'
GOARM64='v8.0'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/Users/emrehn/Library/Caches/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/Users/emrehn/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/50/f2qw2dqn6dv5hsq9mfk7_zlw0000gp/T/go-build117157792=/tmp/go-build -gno-record-gcc-switches -fno-common'
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMOD='/Users/emrehn/Documents/git/test-nlreturn/go.mod'
GOMODCACHE='/Users/emrehn/go/1.24.0/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/emrehn/go/1.24.0'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/emrehn/.goenv/versions/1.24.0'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/emrehn/Library/Application Support/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/emrehn/.goenv/versions/1.24.0/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.24.0'
GOWORK=''
PKG_CONFIG='pkg-config'

Verbose output of running

$ golangci-lint cache clean
$ golangci-lint run -v
INFO golangci-lint has version 2.0.2 built with go1.24.1 from 2b224c2c on 2025-03-25T21:36:18Z 
INFO [config_reader] Config search paths: [./ /Users/emrehn/Documents/git/test-nlreturn /Users/emrehn/Documents/git /Users/emrehn/Documents /Users/emrehn /Users /] 
INFO maxprocs: Leaving GOMAXPROCS=8: CPU quota undefined 
INFO [goenv] Read go env for 10.982667ms: map[string]string{"GOCACHE":"/Users/emrehn/Library/Caches/go-build", "GOROOT":"/Users/emrehn/.goenv/versions/1.24.0"} 
INFO [lintersdb] Active 5 linters: [errcheck govet ineffassign staticcheck unused] 
INFO [loader] Go packages loading at mode 8767 (imports|compiled_files|deps|exports_file|files|name|types_sizes) took 267.376375ms 
INFO [runner/filename_unadjuster] Pre-built 0 adjustments in 1.793375ms 
INFO [linters_context/goanalysis] analyzers took 878.248092ms with top 10 stages: buildir: 585.437248ms, fact_deprecated: 60.726375ms, printf: 47.304998ms, ctrlflow: 38.757214ms, SA5012: 32.662958ms, fact_purity: 28.669753ms, nilness: 26.778172ms, inspect: 25.80021ms, typedness: 25.015751ms, tokenfileanalyzer: 1.35475ms 
INFO [runner] processing took 1.33µs with stages: max_same_issues: 250ns, exclusion_rules: 208ns, exclusion_paths: 208ns, path_absoluter: 167ns, path_shortener: 166ns, nolint_filter: 83ns, path_relativity: 42ns, source_code: 42ns, filename_unadjuster: 41ns, max_from_linter: 41ns, generated_file_filter: 41ns, invalid_issue: 41ns, fixer: 0s, path_prettifier: 0s, sort_results: 0s, diff: 0s, severity-rules: 0s, cgo: 0s, max_per_file_from_linter: 0s, uniq_by_line: 0s 
INFO [runner] linters took 565.383125ms with stages: goanalysis_metalinter: 565.337042ms 
0 issues.
INFO File cache stats: 0 entries of total size 0B 
INFO Memory: 10 samples, avg is 131.5MB, max is 243.9MB 
INFO Execution took 846.381667ms  

A minimal reproducible example or link to a public repository

package main

/*
#include <stdlib.h>
*/
import "C"
import (
        "fmt"
        "unsafe"
)

func testFunc(str string) {
        cstr := C.CString(str)
        defer C.free(unsafe.Pointer(cstr))

        fmt.Printf("%v\n", C.GoString(cstr))
}

func main() {
        testFunc("hello world")
}

Validation

• Yes, I've included all information above (version, config, etc.).

Supporter

• I am a sponsor/backer through GitHub or OpenCollective

[boring-cyborg]

Hey, thank you for opening your first Issue ! 🙂 If you would like to contribute we have a guide for contributors.

[ldez]

Thank you for the report.

Closed in favor of #5235

[bombsimon]

Also worth mentioning that this is an upstream issue: ssgreg/nlreturn#4