package errors
import (
"strconv"
"strings"
)
type uncaughtPanic struct{ message string }
func (p uncaughtPanic) Error() string {
return p.message
}
// ParsePanic allows you to get an error object from the output of a go program
// that panicked. This is particularly useful with https://github.com/mitchellh/panicwrap.
func ParsePanic(text string) (*Error, error) {
lines := strings.Split(text, "\n")
state := "start"
var message string
var stack []StackFrame
for i := 0; i < len(lines); i++ {
line := lines[i]
if state == "start" {
if strings.HasPrefix(line, "panic: ") {
message = strings.TrimPrefix(line, "panic: ")
state = "seek"
} else {
return nil, Errorf("bugsnag.panicParser: Invalid line (no prefix): %s", line)
}
} else if state == "seek" {
if strings.HasPrefix(line, "goroutine ") && strings.HasSuffix(line, "[running]:") {
state = "parsing"
}
} else if state == "parsing" {
if line == "" {
state = "done"
break
}
createdBy := false
if strings.HasPrefix(line, "created by ") {
line = strings.TrimPrefix(line, "created by ")
createdBy = true
}
i++
if i >= len(lines) {
return nil, Errorf("bugsnag.panicParser: Invalid line (unpaired): %s", line)
}
frame, err := parsePanicFrame(line, lines[i], createdBy)
if err != nil {
return nil, err
}
stack = append(stack, *frame)
if createdBy {
state = "done"
break
}
}
}
if state == "done" || state == "parsing" {
return &Error{Err: uncaughtPanic{message}, frames: stack}, nil
}
return nil, Errorf("could not parse panic: %v", text)
}
// The lines we're passing look like this:
//
// main.(*foo).destruct(0xc208067e98)
// /0/go/src/github.com/bugsnag/bugsnag-go/pan/main.go:22 +0x151
func parsePanicFrame(name string, line string, createdBy bool) (*StackFrame, error) {
idx := strings.LastIndex(name, "(")
if idx == -1 && !createdBy {
return nil, Errorf("bugsnag.panicParser: Invalid line (no call): %s", name)
}
if idx != -1 {
name = name[:idx]
}
pkg := ""
if lastslash := strings.LastIndex(name, "/"); lastslash >= 0 {
pkg += name[:lastslash] + "/"
name = name[lastslash+1:]
}
if period := strings.Index(name, "."); period >= 0 {
pkg += name[:period]
name = name[period+1:]
}
name = strings.Replace(name, "·", ".", -1)
if !strings.HasPrefix(line, "\t") {
return nil, Errorf("bugsnag.panicParser: Invalid line (no tab): %s", line)
}
idx = strings.LastIndex(line, ":")
if idx == -1 {
return nil, Errorf("bugsnag.panicParser: Invalid line (no line number): %s", line)
}
file := line[1:idx]
number := line[idx+1:]
if idx = strings.Index(number, " +"); idx > -1 {
number = number[:idx]
}
lno, err := strconv.ParseInt(number, 10, 32)
if err != nil {
return nil, Errorf("bugsnag.panicParser: Invalid line (bad line number): %s", line)
}
return &StackFrame{
File: file,
LineNumber: int(lno),
Package: pkg,
Name: name,
}, nil
}
