Scott Baker | 1fe7273 | 2019-10-21 10:58:51 -0700 | [diff] [blame] | 1 | package errors |
| 2 | |
| 3 | import ( |
| 4 | "strconv" |
| 5 | "strings" |
| 6 | ) |
| 7 | |
| 8 | type uncaughtPanic struct{ message string } |
| 9 | |
| 10 | func (p uncaughtPanic) Error() string { |
| 11 | return p.message |
| 12 | } |
| 13 | |
| 14 | // ParsePanic allows you to get an error object from the output of a go program |
| 15 | // that panicked. This is particularly useful with https://github.com/mitchellh/panicwrap. |
| 16 | func ParsePanic(text string) (*Error, error) { |
| 17 | lines := strings.Split(text, "\n") |
| 18 | |
| 19 | state := "start" |
| 20 | |
| 21 | var message string |
| 22 | var stack []StackFrame |
| 23 | |
| 24 | for i := 0; i < len(lines); i++ { |
| 25 | line := lines[i] |
| 26 | |
| 27 | if state == "start" { |
| 28 | if strings.HasPrefix(line, "panic: ") { |
| 29 | message = strings.TrimPrefix(line, "panic: ") |
| 30 | state = "seek" |
| 31 | } else { |
| 32 | return nil, Errorf("bugsnag.panicParser: Invalid line (no prefix): %s", line) |
| 33 | } |
| 34 | |
| 35 | } else if state == "seek" { |
| 36 | if strings.HasPrefix(line, "goroutine ") && strings.HasSuffix(line, "[running]:") { |
| 37 | state = "parsing" |
| 38 | } |
| 39 | |
| 40 | } else if state == "parsing" { |
| 41 | if line == "" { |
| 42 | state = "done" |
| 43 | break |
| 44 | } |
| 45 | createdBy := false |
| 46 | if strings.HasPrefix(line, "created by ") { |
| 47 | line = strings.TrimPrefix(line, "created by ") |
| 48 | createdBy = true |
| 49 | } |
| 50 | |
| 51 | i++ |
| 52 | |
| 53 | if i >= len(lines) { |
| 54 | return nil, Errorf("bugsnag.panicParser: Invalid line (unpaired): %s", line) |
| 55 | } |
| 56 | |
| 57 | frame, err := parsePanicFrame(line, lines[i], createdBy) |
| 58 | if err != nil { |
| 59 | return nil, err |
| 60 | } |
| 61 | |
| 62 | stack = append(stack, *frame) |
| 63 | if createdBy { |
| 64 | state = "done" |
| 65 | break |
| 66 | } |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | if state == "done" || state == "parsing" { |
| 71 | return &Error{Err: uncaughtPanic{message}, frames: stack}, nil |
| 72 | } |
| 73 | return nil, Errorf("could not parse panic: %v", text) |
| 74 | } |
| 75 | |
| 76 | // The lines we're passing look like this: |
| 77 | // |
| 78 | // main.(*foo).destruct(0xc208067e98) |
| 79 | // /0/go/src/github.com/bugsnag/bugsnag-go/pan/main.go:22 +0x151 |
| 80 | func parsePanicFrame(name string, line string, createdBy bool) (*StackFrame, error) { |
| 81 | idx := strings.LastIndex(name, "(") |
| 82 | if idx == -1 && !createdBy { |
| 83 | return nil, Errorf("bugsnag.panicParser: Invalid line (no call): %s", name) |
| 84 | } |
| 85 | if idx != -1 { |
| 86 | name = name[:idx] |
| 87 | } |
| 88 | pkg := "" |
| 89 | |
| 90 | if lastslash := strings.LastIndex(name, "/"); lastslash >= 0 { |
| 91 | pkg += name[:lastslash] + "/" |
| 92 | name = name[lastslash+1:] |
| 93 | } |
| 94 | if period := strings.Index(name, "."); period >= 0 { |
| 95 | pkg += name[:period] |
| 96 | name = name[period+1:] |
| 97 | } |
| 98 | |
| 99 | name = strings.Replace(name, "ยท", ".", -1) |
| 100 | |
| 101 | if !strings.HasPrefix(line, "\t") { |
| 102 | return nil, Errorf("bugsnag.panicParser: Invalid line (no tab): %s", line) |
| 103 | } |
| 104 | |
| 105 | idx = strings.LastIndex(line, ":") |
| 106 | if idx == -1 { |
| 107 | return nil, Errorf("bugsnag.panicParser: Invalid line (no line number): %s", line) |
| 108 | } |
| 109 | file := line[1:idx] |
| 110 | |
| 111 | number := line[idx+1:] |
| 112 | if idx = strings.Index(number, " +"); idx > -1 { |
| 113 | number = number[:idx] |
| 114 | } |
| 115 | |
| 116 | lno, err := strconv.ParseInt(number, 10, 32) |
| 117 | if err != nil { |
| 118 | return nil, Errorf("bugsnag.panicParser: Invalid line (bad line number): %s", line) |
| 119 | } |
| 120 | |
| 121 | return &StackFrame{ |
| 122 | File: file, |
| 123 | LineNumber: int(lno), |
| 124 | Package: pkg, |
| 125 | Name: name, |
| 126 | }, nil |
| 127 | } |