1// Copyright 2009 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package gob
6
7import "fmt"
8
9// Errors in decoding and encoding are handled using panic and recover.
10// Panics caused by user error (that is, everything except run-time panics
11// such as "index out of bounds" errors) do not leave the file that caused
12// them, but are instead turned into plain error returns. Encoding and
13// decoding functions and methods that do not return an error either use
14// panic to report an error or are guaranteed error-free.
15
16// A gobError is used to distinguish errors (panics) generated in this package.
17type gobError struct {
18	err error
19}
20
21// errorf is like error_ but takes Printf-style arguments to construct an error.
22// It always prefixes the message with "gob: ".
23func errorf(format string, args ...any) {
24	error_(fmt.Errorf("gob: "+format, args...))
25}
26
27// error_ wraps the argument error and uses it as the argument to panic.
28func error_(err error) {
29	panic(gobError{err})
30}
31
32// catchError is meant to be used as a deferred function to turn a panic(gobError) into a
33// plain error. It overwrites the error return of the function that deferred its call.
34func catchError(err *error) {
35	if e := recover(); e != nil {
36		ge, ok := e.(gobError)
37		if !ok {
38			panic(e)
39		}
40		*err = ge.err
41	}
42}
43