Adding upstream version 3.10.8.

Signed-off-by: Daniel Baumann <daniel@debian.org>

util/panic.go

@@ -0,0 +1,98 @@
+// Copyright Earl Warren <contact@earl-warren.org>
+// Copyright Loïc Dachary <loic@dachary.org>
+// SPDX-License-Identifier: MIT
+
+package util
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+)
+
+var packagePrefix string
+
+func init() {
+	_, filename, _, _ := runtime.Caller(0)
+	packagePrefix = strings.TrimSuffix(filename, "util/panic.go")
+	if packagePrefix == filename {
+		// in case the source code file is moved, we can not trim the suffix, the code above should also be updated.
+		panic("unable to detect correct package prefix, please update file: " + filename)
+	}
+}
+
+func getStack() string {
+	callersLength := 5
+	var callers []uintptr
+	var callersCount int
+	for {
+		callers = make([]uintptr, callersLength)
+		callersCount = runtime.Callers(4, callers)
+		if callersCount <= 0 {
+			panic("runtime.Callers <= 0")
+		}
+		if callersCount >= callersLength {
+			callersLength *= 2
+		} else {
+			break
+		}
+	}
+	callers = callers[:callersCount]
+	frames := runtime.CallersFrames(callers)
+	stack := make([]string, 0, 10)
+	for {
+		frame, more := frames.Next()
+		if strings.HasPrefix(frame.File, packagePrefix) {
+			file := strings.TrimPrefix(frame.File, packagePrefix)
+			if file == "util/panic.go" || file == "util/terminate.go" && more {
+				continue
+			}
+			var function string
+			dot := strings.LastIndex(frame.Function, ".")
+			if dot >= 0 {
+				function = frame.Function[dot+1:]
+			}
+			stack = append(stack, fmt.Sprintf("%s:%d:%s", file, frame.Line, function))
+		}
+		if !more {
+			break
+		}
+	}
+	return strings.Join(stack, "\n") + "\n"
+}
+
+type PanicError interface {
+	error
+	Stack() string
+}
+
+type panicError struct {
+	message string
+	stack   string
+}
+
+func (o panicError) Error() string { return o.message }
+func (o panicError) Stack() string { return o.stack }
+
+func PanicToError(fun func()) (err PanicError) {
+	defer func() {
+		if r := recover(); r != nil {
+			recoveredErr, ok := r.(error)
+			var message string
+			if ok {
+				message = recoveredErr.Error()
+			}
+			err = panicError{
+				message: message,
+				stack:   getStack(),
+			}
+			if !ok {
+				panic(r)
+			}
+		}
+	}()
+
+	fun()
+
+	return err
+}