stacktrace.go

// Package stacktrace captures and formats Go call stacks.

package stacktrace

import "runtime"

// Frame holds a single stack frame.

type Frame struct {

	Function string

	File     string

	Line     int

}

// Trace is an ordered list of stack frames, outermost first.

type Trace []Frame

// Capture returns the current call stack, skipping skip frames from

// the caller's perspective. skip=0 means the caller of Capture is the

// first frame.

func Capture(skip int) Trace {

	const depth = 64

	var pcs [depth]uintptr

	// skip+2: one for runtime.Callers itself, one for Capture.

	n := runtime.Callers(skip+2, pcs[:])

	if n == 0 {

		return nil

	}

	frames := runtime.CallersFrames(pcs[:n])

	var trace Trace

	for {

		f, more := frames.Next()

		trace = append(trace, Frame{

			Function: f.Function,

			File:     f.File,

			Line:     f.Line,

		})

		if !more {

			break

		}

	}

	return trace

}