fix parsing go1.23 stack traces

Go 1.21 changed how the runtime prints deep stacks:
golang/go@9eba17f

fixes #90

Author: stapelberg

.github/workflows/test.yml

@@ -20,7 +20,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
         # Do not forget to bump every 6 months!
-        gover: ["1.20"]
+        gover: ["1.23"]
     env:
       PYTHONDONTWRITEBYTECODE: x
     steps:
@@ -265,7 +265,7 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         # Do not forget to bump every 6 months!
-        gover: ["1.20"]
+        gover: ["1.23"]
     permissions:
       security-events: write
     steps:

stack/context.go

@@ -252,7 +252,6 @@ const pathSeparator = string(filepath.Separator)
 
 var (
 	lockedToThread = []byte("locked to thread")
-	framesElided   = []byte("...additional frames elided...")
 	// gotRaceHeader1, done
 	raceHeaderFooter = []byte("==================")
 	// gotRaceHeader2
@@ -270,7 +269,7 @@ var (
 // These are effectively constants.
 var (
 	// gotRoutineHeader
-	reRoutineHeader = regexp.MustCompile("^([ \t]*)goroutine (\\d+) \\[([^\\]]+)\\]\\:$")
+	reRoutineHeader = regexp.MustCompile("^([ \t]*)goroutine (\\d+)(?: gp=[^ ]+ m=[^ ]+(?: mp=[^ ]+)?)? \\[([^\\]]+)\\]\\:$")
 	reMinutes       = regexp.MustCompile(`^(\d+) minutes$`)
 
 	// gotUnavail
@@ -450,6 +449,18 @@ type scanningState struct {
 	goroutineIndex int
 }
 
+func isFramesElidedLine(line []byte) bool {
+	// before go1.21:
+	// ...additional frames elided...
+	//
+	// go1.21 and newer:
+	// print("...", elide, " frames elided...\n")
+	framesElided := []byte("...additional frames elided...")
+	return bytes.Equal(line, framesElided) ||
+		bytes.HasPrefix(line, []byte("...")) &&
+			bytes.HasSuffix(line, []byte(" frames elided..."))
+}
+
 // scan scans one line, updates goroutines and move to the next state.
 //
 // Returns true if the line was processed and thus should not be printed out.
@@ -605,7 +616,7 @@ func (s *scanningState) scan(line []byte) (bool, error) {
 			s.state = gotCreated
 			return true, nil
 		}
-		if bytes.Equal(trimmed, framesElided) {
+		if isFramesElidedLine(trimmed) {
 			cur.Stack.Elided = true
 			// TODO(maruel): New state.
 			return true, nil

stack/context_test.go

@@ -2350,7 +2350,7 @@ func identifyPanicwebSignature(t *testing.T, b *Bucket, pwebDir string) panicweb
 				t.Fatal("expected Locked")
 			}
 			// This is a change detector on internal/main.go.
-			want := Stack{Calls: []Call{newCallLocal("main.main", Args{}, pathJoin(pwebDir, "main.go"), 145)}}
+			want := Stack{Calls: []Call{newCallLocal("main.main in goroutine 1", Args{}, pathJoin(pwebDir, "main.go"), 145)}}
 			compareStacks(t, &b.Signature.CreatedBy, &want)
 			for i := range b.Signature.Stack.Calls {
 				if strings.HasPrefix(b.Signature.Stack.Calls[i].ImportPath, "github.com/mattn/go-colorable") {
@@ -2364,7 +2364,7 @@ func identifyPanicwebSignature(t *testing.T, b *Bucket, pwebDir string) panicweb
 			{
 				want := Stack{
 					Calls: []Call{
-						newCallLocal("main.main", Args{}, pathJoin(pwebDir, "main.go"), 63),
+						newCallLocal("main.main in goroutine 1", Args{}, pathJoin(pwebDir, "main.go"), 63),
 					},
 				}
 				zapStacks(t, &want, &b.CreatedBy)

stack/source_test.go

@@ -494,9 +494,12 @@ func TestAugment(t *testing.T) {
 						"main.f",
 						Args{
 							Values: []Arg{{IsAggregate: true, Fields: Args{
-								Values: []Arg{{Value: pointer, IsPtr: true}, {Value: 3}},
+								Values: []Arg{
+									{Value: pointer, IsPtr: true},
+									{Value: pointer, IsPtr: true},
+								},
 							}}},
-							Processed: []string{"error{0x2fffffff, 0x3}"},
+							Processed: []string{"error{0x2fffffff, 0x2fffffff}"},
 						},
 						"/root/main.go",
 						7),

stack/stack.go

@@ -79,6 +79,14 @@ func (f *Func) Init(raw string) error {
 		f.ImportPath = f.Complete[:endPkg]
 	}
 	f.Name = f.Complete[endPkg+1:]
+	if idx := strings.LastIndexByte(f.Name, ' '); idx > -1 {
+		cut := f.Name[:idx]
+		// TODO(go1.20): switch to strings.CutSuffix
+		const inGoroutineSuffix = " in goroutine"
+		if strings.HasSuffix(cut, inGoroutineSuffix) {
+			f.Name = strings.TrimSuffix(cut, inGoroutineSuffix)
+		}
+	}
 	f.DirName = f.ImportPath
 	if i := strings.LastIndexByte(f.DirName, '/'); i != -1 {
 		f.DirName = f.DirName[i+1:]