decode,fuzz,dev: Move recoverable error check to recoverfn.Run

This preserves the callstack on non-recoverable panics so that using
a debugger and fuzzing is much easier.

Add vscode debug config.
Remove fuzz stacktrace log workaround.

.vscode/launch.json

@@ -0,0 +1,21 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Debug fq",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "showLog": true,
+            "program": ".",
+            "cwd": "${workspaceFolder}",
+            "env": {},
+            "args": [
+                "-d",
+                "mp4",
+                ".",
+                "file"
+            ],
+        }
+    ]
+}

.vscode/settings.json

@@ -61,6 +61,7 @@
         "gojqex",
         "golangci",
         "gopacket",
+        "gopanic",
         "GOPATH",
         "gosec",
         "gosimple",
@@ -154,6 +155,8 @@
         "tfhd",
         "tfra",
         "tmpl",
+        "to_xml",
+        "to_xmlentities",
         "toactual",
         "toarray",
         "toboolean",
@@ -167,8 +170,6 @@
         "torepr",
         "tosym",
         "tovalue",
-        "to_xml",
-        "to_xmlentities",
         "traf",
         "trak",
         "trex",

Makefile

@@ -92,7 +92,7 @@ update-gomod: always
 # fq -n '"..." | from_base64 | ...'
 fuzz: always
 # in other terminal: tail -f /tmp/repanic
-	FUZZTEST=1 REPANIC_LOG=/tmp/repanic go test -v -run Fuzz -fuzz=Fuzz ./format/
+	FUZZTEST=1 go test -v -run Fuzz -fuzz=Fuzz ./format/
 
 # usage: make release VERSION=0.0.1
 # tag forked dependeces for history and to make then stay around

internal/recoverfn/recoverfn.go

@@ -1,9 +1,6 @@
 package recoverfn
 
 import (
-	"fmt"
-	"io"
-	"os"
 	"runtime"
 )
 
@@ -15,8 +12,13 @@ type Raw struct {
 	PCs       []uintptr
 }
 
-// Run runs fn and return Raw{}, true on no-panic
-// on panic it recovers and return a raw stacktrace and panic value to inspect
+type RecoverableErrorer interface {
+	IsRecoverableError() bool
+}
+
+// Run runs fn and return Raw{}, true for no panic
+// If panic is recoverable raw stacktrace and panic value is returned
+// If panic is not recoverable we just panic again
 func Run(fn func()) (Raw, bool) {
 	// TODO: once?
 	var recoverPC [1]uintptr
@@ -24,10 +26,14 @@ func Run(fn func()) (Raw, bool) {
 
 	pc, v := func() (pcs []uintptr, v any) {
 		defer func() {
-			if recoverErr := recover(); recoverErr != nil {
-				pcs = make([]uintptr, stackSizeLimit)
-				pcs = pcs[0:runtime.Callers(0, pcs)]
-				v = recoverErr
+			if recoverV := recover(); recoverV != nil {
+				if re, ok := recoverV.(RecoverableErrorer); ok && re.IsRecoverableError() {
+					pcs = make([]uintptr, stackSizeLimit)
+					pcs = pcs[0:runtime.Callers(0, pcs)]
+					v = recoverV
+					return
+				}
+				panic(recoverV)
 			}
 		}()
 
@@ -81,21 +87,3 @@ func (r Raw) Frames() []runtime.Frame {
 	// 1 to skip Recover defer recover() function
 	return r.frames(3, 1, r.RecoverPC)
 }
-
-func (r Raw) RePanic() {
-	var o io.Writer
-	o = os.Stderr
-	if p := os.Getenv("REPANIC_LOG"); p != "" {
-		if f, err := os.Create(p); err == nil {
-			o = f
-			defer f.Close()
-		}
-	}
-
-	fmt.Fprintf(o, "repanic: %v\n", r.RecoverV)
-	for _, f := range r.frames(0, 0, 0) {
-		fmt.Fprintf(o, "%s\n", f.Function)
-		fmt.Fprintf(o, "\t%s:%d\n", f.File, f.Line)
-	}
-	panic(r.RecoverV)
-}

internal/recoverfn/recoverfn_test.go

@@ -8,13 +8,17 @@ import (
 )
 
 func test1() {
-	panic("hello")
+	panic(testError(true))
 }
 
 func test2() {
 	test1()
 }
 
+type testError bool
+
+func (t testError) IsRecoverableError() bool { return bool(t) }
+
 func TestNormal(t *testing.T) {
 	_, rOk := recoverfn.Run(func() {})
 	expectedROK := true
@@ -31,9 +35,8 @@ func TestPanic(t *testing.T) {
 		t.Errorf("expected v %v, got %v", expectedROK, rOk)
 	}
 
-	expectedV := "hello"
-	if !reflect.DeepEqual(expectedV, r.RecoverV) {
-		t.Errorf("expected v %v, got %v", expectedV, r.RecoverV)
+	if _, ok := r.RecoverV.(testError); !ok {
+		t.Errorf("expected v %v, got %v", testError(true), r.RecoverV)
 	}
 
 	frames := r.Frames()

pkg/decode/decode.go

@@ -106,27 +106,29 @@ func decode(ctx context.Context, br bitio.ReaderAtSeeker, group Group, opts Opti
 		}
 
 		if !rOk {
-			if re, ok := r.RecoverV.(RecoverableErrorer); ok && re.IsRecoverableError() {
-				panicErr, _ := re.(error)
-				formatErr := FormatError{
-					Err:        panicErr,
-					Format:     f,
-					Stacktrace: r,
-				}
-				formatsErr.Errs = append(formatsErr.Errs, formatErr)
-
-				switch vv := d.Value.V.(type) {
-				case *Compound:
-					// TODO: hack, changes V
-					d.Value.V = vv
-					d.Value.Err = formatErr
-				}
-
-				if len(group) != 1 {
-					continue
-				}
+			var panicErr error
+			if err, ok := r.RecoverV.(error); ok {
+				panicErr = err
 			} else {
-				r.RePanic()
+				panicErr = fmt.Errorf("recoverable non-panic error :%v", r.RecoverV)
+			}
+
+			formatErr := FormatError{
+				Err:        panicErr,
+				Format:     f,
+				Stacktrace: r,
+			}
+			formatsErr.Errs = append(formatsErr.Errs, formatErr)
+
+			switch vv := d.Value.V.(type) {
+			case *Compound:
+				// TODO: hack, changes V
+				d.Value.V = vv
+				d.Value.Err = formatErr
+			}
+
+			if len(group) != 1 {
+				continue
 			}
 		}