xref: /third_party/gn/src/base/json/string_escape.h (revision 6d528ed9)
1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// This file defines utility functions for escaping strings suitable for JSON.
6
7#ifndef BASE_JSON_STRING_ESCAPE_H_
8#define BASE_JSON_STRING_ESCAPE_H_
9
10#include <string>
11#include <string_view>
12
13namespace base {
14
15// Appends to |dest| an escaped version of |str|. Valid UTF-8 code units and
16// characters will pass through from the input to the output. Invalid code
17// units and characters will be replaced with the U+FFFD replacement character.
18// This function returns true if no replacement was necessary and false if
19// there was a lossy replacement. On return, |dest| will contain a valid UTF-8
20// JSON string.
21//
22// Non-printing control characters will be escaped as \uXXXX sequences for
23// readability.
24//
25// If |put_in_quotes| is true, then a leading and trailing double-quote mark
26// will be appended to |dest| as well.
27void EscapeJSONString(std::string_view str,
28                      bool put_in_quotes,
29                      std::string* dest);
30
31// Performs a similar function to the UTF-8 std::string_view version above,
32// converting UTF-16 code units to UTF-8 code units and escaping non-printing
33// control characters. On return, |dest| will contain a valid UTF-8 JSON string.
34void EscapeJSONString(std::u16string_view str,
35                      bool put_in_quotes,
36                      std::string* dest);
37
38// Given an arbitrary byte string |str|, this will escape all non-ASCII bytes
39// as \uXXXX escape sequences. This function is *NOT* meant to be used with
40// Unicode strings and does not validate |str| as one.
41//
42// CAVEAT CALLER: The output of this function may not be valid JSON, since
43// JSON requires escape sequences to be valid UTF-16 code units. This output
44// will be mangled if passed to to the base::JSONReader, since the reader will
45// interpret it as UTF-16 and convert it to UTF-8.
46//
47// The output of this function takes the *appearance* of JSON but is not in
48// fact valid according to RFC 4627.
49std::string EscapeBytesAsInvalidJSONString(std::string_view str,
50                                           bool put_in_quotes);
51
52}  // namespace base
53
54#endif  // BASE_JSON_STRING_ESCAPE_H_
55