QF1008: False positive when overriding a method on deeply embedded struct #1682
Description
Code:
package main
import "fmt"
type Embedded2 struct {
Output *string
}
func (e Embedded2) String() string {
return *e.Output
}
type Embedded struct {
Embedded2
}
type Wrapper struct {
Embedded
}
func (w Wrapper) String() string {
if w.Embedded.Embedded2.Output != nil {
return w.Embedded.Embedded2.String()
}
return ""
}
func main() {
s := "test"
w := Wrapper{
Embedded{
Embedded2{
Output: &s,
},
},
}
fmt.Println(w.String())
}Result:
test
Result of golangci-lint:
cmd/testgci/testgci.go:22:7: QF1008: could remove embedded field "Embedded" from selector (staticcheck)
if w.Embedded.Embedded2.Output != nil {
^
cmd/testgci/testgci.go:23:12: QF1008: could remove embedded field "Embedded" from selector (staticcheck)
return w.Embedded.Embedded2.String()
^
2 issues:
* staticcheck: 2
After running golangci-lint --fix:
package main
import "fmt"
type Embedded2 struct {
Output *string
}
func (e Embedded2) String() string {
return *e.Output
}
type Embedded struct {
Embedded2
}
type Wrapper struct {
Embedded
}
func (w Wrapper) String() string {
if w.Output != nil {
return w.String()
}
return ""
}
func main() {
s := "test"
w := Wrapper{
Embedded{
Embedded2{
Output: &s,
},
},
}
fmt.Println(w.String())
}Output:
runtime: goroutine stack exceeds 1000000000-byte limit
runtime: sp=0xc020160388 stack=[0xc020160000, 0xc040160000]
fatal error: stack overflow
runtime stack:
runtime.throw({0x4bdc1a?, 0x413045?})
/nix/store/3fd683jfggglpshxprz9mi5sz8wd3c9p-go-1.25.0/share/go/src/runtime/panic.go:1094 +0x48 fp=0x7fff7af4aa38 sp=0x7fff7af4aa08 pc=0x46dc08
runtime.newstack()
/nix/store/3fd683jfggglpshxprz9mi5sz8wd3c9p-go-1.25.0/share/go/src/runtime/stack.go:1159 +0x5bd fp=0x7fff7af4ab68 sp=0x7fff7af4aa38 pc=0x455b9d
runtime.morestack()
/nix/store/3fd683jfggglpshxprz9mi5sz8wd3c9p-go-1.25.0/share/go/src/runtime/asm_amd64.s:620 +0x7d fp=0x7fff7af4ab70 sp=0x7fff7af4ab68 pc=0x47221d
goroutine 1 gp=0xc000002380 m=0 mp=0x571be0 [running]:
main.Wrapper.String({{{0xc04015ff20?}}})
/src/cmd/testgci/testgci.go:21 +0x32 fp=0xc020160398 sp=0xc020160390 pc=0x498132
main.Wrapper.String(...)
/src/cmd/testgci/testgci.go:23
main.Wrapper.String({{{0x0?}}})
/src/cmd/testgci/testgci.go:23 +0x18 fp=0xc0201603b0 sp=0xc020160398 pc=0x498118
Expected result: It should keep return w.Embedded.Embedded2.String()
I've tried without Embedded2 (inline Embedded2 into Embedded), which the refactor correctly change the return to return w.Embedded.String().
Version: golangci-lint has version v2.4.0-custom-gcl-47DEQpj8HBSaTImW5JCeuQeRkm5NMpJWZG3hSuFU built with go1.25.0 from ? on 2025-10-08 08:56:29.481973397 +0000 UTC