Is it possible get information about caller function in Golang?
You can use runtime.Caller
for easily retrieving information about the caller:
func Caller(skip int) (pc uintptr, file string, line int, ok bool)
Example #1: Print caller file name and line number: https://play.golang.org/p/cdO4Z4ApHS
package main
import (
"fmt"
"runtime"
)
func foo() {
_, file, no, ok := runtime.Caller(1)
if ok {
fmt.Printf("called from %s#%d\n", file, no)
}
}
func main() {
foo()
}
Example #2: Get more information with runtime.FuncForPC
: https://play.golang.org/p/y8mpQq2mAv
package main
import (
"fmt"
"runtime"
)
func foo() {
pc, _, _, ok := runtime.Caller(1)
details := runtime.FuncForPC(pc)
if ok && details != nil {
fmt.Printf("called from %s\n", details.Name())
}
}
func main() {
foo()
}
expanding on my comment, here's some code that returns the current func's caller
import(
"fmt"
"runtime"
)
func getFrame(skipFrames int) runtime.Frame {
// We need the frame at index skipFrames+2, since we never want runtime.Callers and getFrame
targetFrameIndex := skipFrames + 2
// Set size to targetFrameIndex+2 to ensure we have room for one more caller than we need
programCounters := make([]uintptr, targetFrameIndex+2)
n := runtime.Callers(0, programCounters)
frame := runtime.Frame{Function: "unknown"}
if n > 0 {
frames := runtime.CallersFrames(programCounters[:n])
for more, frameIndex := true, 0; more && frameIndex <= targetFrameIndex; frameIndex++ {
var frameCandidate runtime.Frame
frameCandidate, more = frames.Next()
if frameIndex == targetFrameIndex {
frame = frameCandidate
}
}
}
return frame
}
// MyCaller returns the caller of the function that called it :)
func MyCaller() string {
// Skip GetCallerFunctionName and the function to get the caller of
return getFrame(2).Function
}
// foo calls MyCaller
func foo() {
fmt.Println(MyCaller())
}
// bar is what we want to see in the output - it is our "caller"
func bar() {
foo()
}
func main(){
bar()
}
For more examples: https://play.golang.org/p/cv-SpkvexuM