forked from getsentry/sentry-go
-
Notifications
You must be signed in to change notification settings - Fork 0
/
stacktrace.go
343 lines (286 loc) · 9.66 KB
/
stacktrace.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
package sentry
import (
"go/build"
"path/filepath"
"reflect"
"runtime"
"strings"
)
const unknown string = "unknown"
// The module download is split into two parts: downloading the go.mod and downloading the actual code.
// If you have dependencies only needed for tests, then they will show up in your go.mod,
// and go get will download their go.mods, but it will not download their code.
// The test-only dependencies get downloaded only when you need it, such as the first time you run go test.
//
// https://github.com/golang/go/issues/26913#issuecomment-411976222
// Stacktrace holds information about the frames of the stack.
type Stacktrace struct {
Frames []Frame `json:"frames,omitempty"`
FramesOmitted []uint `json:"frames_omitted,omitempty"`
}
// NewStacktrace creates a stacktrace using runtime.Callers.
func NewStacktrace() *Stacktrace {
pcs := make([]uintptr, 100)
n := runtime.Callers(1, pcs)
if n == 0 {
return nil
}
frames := extractFrames(pcs[:n])
frames = filterFrames(frames)
stacktrace := Stacktrace{
Frames: frames,
}
return &stacktrace
}
// TODO: Make it configurable so that anyone can provide their own implementation?
// Use of reflection allows us to not have a hard dependency on any given
// package, so we don't have to import it.
// ExtractStacktrace creates a new Stacktrace based on the given error.
func ExtractStacktrace(err error) *Stacktrace {
method := extractReflectedStacktraceMethod(err)
var pcs []uintptr
if method.IsValid() {
pcs = extractPcs(method)
} else {
pcs = extractXErrorsPC(err)
}
if len(pcs) == 0 {
return nil
}
frames := extractFrames(pcs)
frames = filterFrames(frames)
stacktrace := Stacktrace{
Frames: frames,
}
return &stacktrace
}
func extractReflectedStacktraceMethod(err error) reflect.Value {
errValue := reflect.ValueOf(err)
// https://github.com/go-errors/errors
methodStackFrames := errValue.MethodByName("StackFrames")
if methodStackFrames.IsValid() {
return methodStackFrames
}
// https://github.com/pkg/errors
methodStackTrace := errValue.MethodByName("StackTrace")
if methodStackTrace.IsValid() {
return methodStackTrace
}
// https://github.com/pingcap/errors
methodGetStackTracer := errValue.MethodByName("GetStackTracer")
if methodGetStackTracer.IsValid() {
stacktracer := methodGetStackTracer.Call(nil)[0]
stacktracerStackTrace := reflect.ValueOf(stacktracer).MethodByName("StackTrace")
if stacktracerStackTrace.IsValid() {
return stacktracerStackTrace
}
}
return reflect.Value{}
}
func extractPcs(method reflect.Value) []uintptr {
var pcs []uintptr
stacktrace := method.Call(nil)[0]
if stacktrace.Kind() != reflect.Slice {
return nil
}
for i := 0; i < stacktrace.Len(); i++ {
pc := stacktrace.Index(i)
switch pc.Kind() {
case reflect.Uintptr:
pcs = append(pcs, uintptr(pc.Uint()))
case reflect.Struct:
for _, fieldName := range []string{"ProgramCounter", "PC"} {
field := pc.FieldByName(fieldName)
if !field.IsValid() {
continue
}
if field.Kind() == reflect.Uintptr {
pcs = append(pcs, uintptr(field.Uint()))
break
}
}
}
}
return pcs
}
// extractXErrorsPC extracts program counters from error values compatible with
// the error types from golang.org/x/xerrors.
//
// It returns nil if err is not compatible with errors from that package or if
// no program counters are stored in err.
func extractXErrorsPC(err error) []uintptr {
// This implementation uses the reflect package to avoid a hard dependency
// on third-party packages.
// We don't know if err matches the expected type. For simplicity, instead
// of trying to account for all possible ways things can go wrong, some
// assumptions are made and if they are violated the code will panic. We
// recover from any panic and ignore it, returning nil.
//nolint: errcheck
defer func() { recover() }()
field := reflect.ValueOf(err).Elem().FieldByName("frame") // type Frame struct{ frames [3]uintptr }
field = field.FieldByName("frames")
field = field.Slice(1, field.Len()) // drop first pc pointing to xerrors.New
pc := make([]uintptr, field.Len())
for i := 0; i < field.Len(); i++ {
pc[i] = uintptr(field.Index(i).Uint())
}
return pc
}
// Frame represents a function call and it's metadata. Frames are associated
// with a Stacktrace.
type Frame struct {
Function string `json:"function,omitempty"`
Symbol string `json:"symbol,omitempty"`
// Module is, despite the name, the Sentry protocol equivalent of a Go
// package's import path.
Module string `json:"module,omitempty"`
// Package is not used for Go stack trace frames. In other platforms it
// refers to a container where the Module can be found. For example, a
// Java JAR, a .NET Assembly, or a native dynamic library.
// It exists for completeness, allowing the construction and reporting
// of custom event payloads.
Package string `json:"package,omitempty"`
Filename string `json:"filename,omitempty"`
AbsPath string `json:"abs_path,omitempty"`
Lineno int `json:"lineno,omitempty"`
Colno int `json:"colno,omitempty"`
PreContext []string `json:"pre_context,omitempty"`
ContextLine string `json:"context_line,omitempty"`
PostContext []string `json:"post_context,omitempty"`
InApp bool `json:"in_app,omitempty"`
Vars map[string]interface{} `json:"vars,omitempty"`
}
// NewFrame assembles a stacktrace frame out of runtime.Frame.
func NewFrame(f runtime.Frame) Frame {
var abspath, relpath string
// NOTE: f.File paths historically use forward slash as path separator even
// on Windows, though this is not yet documented, see
// https://golang.org/issues/3335. In any case, filepath.IsAbs can work with
// paths with either slash or backslash on Windows.
switch {
case f.File == "":
relpath = unknown
// Leave abspath as the empty string to be omitted when serializing
// event as JSON.
abspath = ""
case filepath.IsAbs(f.File):
abspath = f.File
// TODO: in the general case, it is not trivial to come up with a
// "project relative" path with the data we have in run time.
// We shall not use filepath.Base because it creates ambiguous paths and
// affects the "Suspect Commits" feature.
// For now, leave relpath empty to be omitted when serializing the event
// as JSON. Improve this later.
relpath = ""
default:
// f.File is a relative path. This may happen when the binary is built
// with the -trimpath flag.
relpath = f.File
// Omit abspath when serializing the event as JSON.
abspath = ""
}
function := f.Function
var pkg string
if function != "" {
pkg, function = splitQualifiedFunctionName(function)
}
frame := Frame{
AbsPath: abspath,
Filename: relpath,
Lineno: f.Line,
Module: pkg,
Function: function,
}
frame.InApp = isInAppFrame(frame)
return frame
}
// splitQualifiedFunctionName splits a package path-qualified function name into
// package name and function name. Such qualified names are found in
// runtime.Frame.Function values.
func splitQualifiedFunctionName(name string) (pkg string, fun string) {
pkg = packageName(name)
fun = strings.TrimPrefix(name, pkg+".")
return
}
func extractFrames(pcs []uintptr) []Frame {
var frames = make([]Frame, 0, len(pcs))
callersFrames := runtime.CallersFrames(pcs)
for {
callerFrame, more := callersFrames.Next()
frames = append(frames, NewFrame(callerFrame))
if !more {
break
}
}
// reverse
for i, j := 0, len(frames)-1; i < j; i, j = i+1, j-1 {
frames[i], frames[j] = frames[j], frames[i]
}
return frames
}
// filterFrames filters out stack frames that are not meant to be reported to
// Sentry. Those are frames internal to the SDK or Go.
func filterFrames(frames []Frame) []Frame {
if len(frames) == 0 {
return nil
}
// reuse
filteredFrames := frames[:0]
for _, frame := range frames {
// Skip Go internal frames.
if frame.Module == "runtime" || frame.Module == "testing" {
continue
}
// Skip Sentry internal frames, except for frames in _test packages (for
// testing).
if strings.HasPrefix(frame.Module, "github.com/getsentry/sentry-go") &&
!strings.HasSuffix(frame.Module, "_test") {
continue
}
filteredFrames = append(filteredFrames, frame)
}
return filteredFrames
}
func isInAppFrame(frame Frame) bool {
if strings.HasPrefix(frame.AbsPath, build.Default.GOROOT) ||
strings.Contains(frame.Module, "vendor") ||
strings.Contains(frame.Module, "third_party") {
return false
}
return true
}
func callerFunctionName() string {
pcs := make([]uintptr, 1)
runtime.Callers(3, pcs)
callersFrames := runtime.CallersFrames(pcs)
callerFrame, _ := callersFrames.Next()
return baseName(callerFrame.Function)
}
// packageName returns the package part of the symbol name, or the empty string
// if there is none.
// It replicates https://golang.org/pkg/debug/gosym/#Sym.PackageName, avoiding a
// dependency on debug/gosym.
func packageName(name string) string {
// A prefix of "type." and "go." is a compiler-generated symbol that doesn't belong to any package.
// See variable reservedimports in cmd/compile/internal/gc/subr.go
if strings.HasPrefix(name, "go.") || strings.HasPrefix(name, "type.") {
return ""
}
pathend := strings.LastIndex(name, "/")
if pathend < 0 {
pathend = 0
}
if i := strings.Index(name[pathend:], "."); i != -1 {
return name[:pathend+i]
}
return ""
}
// baseName returns the symbol name without the package or receiver name.
// It replicates https://golang.org/pkg/debug/gosym/#Sym.BaseName, avoiding a
// dependency on debug/gosym.
func baseName(name string) string {
if i := strings.LastIndex(name, "."); i != -1 {
return name[i+1:]
}
return name
}