An example of mild log tracing capabilities with x/exp/slog; https://go.dev/play/p/U-R1tFhuI13

logtrace.go

package main

import (
	"fmt"
	"os"
	"runtime"

	log "golang.org/x/exp/slog"
)

func trace() string {
	pc, file, line, _ := runtime.Caller(1)
	return fmt.Sprintf("%s:%d:%s", file, line, runtime.FuncForPC(pc).Name())
}

func funcName() string {
	pc, file, _, _ := runtime.Caller(1)
	return fmt.Sprintf("%s:%s", file, runtime.FuncForPC(pc).Name())
}

func foo(l *log.Logger) {
	l = l.With("func", funcName())
	l.Info("lol")
}

func main() {
	l := log.New(log.NewJSONHandler(os.Stdout))
	foo(l)
	l.Info("lmao", "line", trace())
}

You could also potentially do the defer f()() pattern seen here but I'm half awake and not sure how to impl this cleanly (ie. ideally this would all be wrapped up in a single line and still give you the With() context in other logs in the func)