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// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_JSON_PARSER_H_
#define V8_JSON_PARSER_H_
#include "src/factory.h"
#include "src/objects.h"
namespace v8 {
namespace internal {
enum ParseElementResult { kElementFound, kElementNotFound, kNullHandle };
class JsonParseInternalizer BASE_EMBEDDED {
static MaybeHandle<Object> Internalize(Isolate* isolate,
Handle<Object> object,
Handle<Object> reviver);
JsonParseInternalizer(Isolate* isolate, Handle<JSReceiver> reviver)
: isolate_(isolate), reviver_(reviver) {}
MaybeHandle<Object> InternalizeJsonProperty(Handle<JSReceiver> holder,
Handle<String> key);
bool RecurseAndApply(Handle<JSReceiver> holder, Handle<String> name);
Isolate* isolate_;
Handle<JSReceiver> reviver_;
// A simple json parser.
template <bool seq_one_byte>
class JsonParser BASE_EMBEDDED {
MUST_USE_RESULT static MaybeHandle<Object> Parse(Isolate* isolate,
Handle<String> source,
Handle<Object> reviver) {
PostponeInterruptsScope no_debug_breaks(isolate, StackGuard::DEBUGBREAK);
Handle<Object> result;
JsonParser(isolate, source).ParseJson(), Object);
if (reviver->IsCallable()) {
return JsonParseInternalizer::Internalize(isolate, result, reviver);
return result;
static const int kEndOfString = -1;
JsonParser(Isolate* isolate, Handle<String> source);
// Parse a string containing a single JSON value.
MaybeHandle<Object> ParseJson();
INLINE(void Advance());
// The JSON lexical grammar is specified in the ECMAScript 5 standard,
// section The only allowed whitespace characters between tokens
// are tab, carriage-return, newline and space.
INLINE(void AdvanceSkipWhitespace());
INLINE(void SkipWhitespace());
INLINE(uc32 AdvanceGetChar());
// Checks that current charater is c.
// If so, then consume c and skip whitespace.
INLINE(bool MatchSkipWhiteSpace(uc32 c));
// A JSON string (production JSONString) is subset of valid JavaScript string
// literals. The string must only be double-quoted (not single-quoted), and
// the only allowed backslash-escapes are ", /, \, b, f, n, r, t and
// four-digit hex escapes (uXXXX). Any other use of backslashes is invalid.
Handle<String> ParseJsonString() {
return ScanJsonString<false>();
bool ParseJsonString(Handle<String> expected);
Handle<String> ParseJsonInternalizedString() {
Handle<String> result = ScanJsonString<true>();
if (result.is_null()) return result;
return factory()->InternalizeString(result);
template <bool is_internalized>
Handle<String> ScanJsonString();
// Creates a new string and copies prefix[start..end] into the beginning
// of it. Then scans the rest of the string, adding characters after the
// prefix. Called by ScanJsonString when reaching a '\' or non-Latin1 char.
template <typename StringType, typename SinkChar>
Handle<String> SlowScanJsonString(Handle<String> prefix, int start, int end);
// A JSON number (production JSONNumber) is a subset of the valid JavaScript
// decimal number literals.
// It includes an optional minus sign, must have at least one
// digit before and after a decimal point, may not have prefixed zeros (unless
// the integer part is zero), and may include an exponent part (e.g., "e-10").
// Hexadecimal and octal numbers are not allowed.
Handle<Object> ParseJsonNumber();
// Parse a single JSON value from input (grammar production JSONValue).
// A JSON value is either a (double-quoted) string literal, a number literal,
// one of "true", "false", or "null", or an object or array literal.
Handle<Object> ParseJsonValue();
// Parse a JSON object literal (grammar production JSONObject).
// An object literal is a squiggly-braced and comma separated sequence
// (possibly empty) of key/value pairs, where the key is a JSON string
// literal, the value is a JSON value, and the two are separated by a colon.
// A JSON array doesn't allow numbers and identifiers as keys, like a
// JavaScript array.
Handle<Object> ParseJsonObject();
// Helper for ParseJsonObject. Parses the form "123": obj, which is recorded
// as an element, not a property.
ParseElementResult ParseElement(Handle<JSObject> json_object);
// Parses a JSON array literal (grammar production JSONArray). An array
// literal is a square-bracketed and comma separated sequence (possibly empty)
// of JSON values.
// A JSON array doesn't allow leaving out values from the sequence, nor does
// it allow a terminal comma, like a JavaScript array does.
Handle<Object> ParseJsonArray();
// Mark that a parsing error has happened at the current token, and
// return a null handle. Primarily for readability.
inline Handle<Object> ReportUnexpectedCharacter() {
return Handle<Object>::null();
inline Isolate* isolate() { return isolate_; }
inline Factory* factory() { return isolate_->factory(); }
inline Handle<JSFunction> object_constructor() { return object_constructor_; }
static const int kInitialSpecialStringLength = 32;
static const int kPretenureTreshold = 100 * 1024;
Zone* zone() { return &zone_; }
void CommitStateToJsonObject(Handle<JSObject> json_object, Handle<Map> map,
Vector<const Handle<Object>> properties);
Handle<String> source_;
int source_length_;
Handle<SeqOneByteString> seq_source_;
PretenureFlag pretenure_;
Isolate* isolate_;
Zone zone_;
Handle<JSFunction> object_constructor_;
uc32 c0_;
int position_;
// Property handles are stored here inside ParseJsonObject.
ZoneVector<Handle<Object>> properties_;
} // namespace internal
} // namespace v8
#endif // V8_JSON_PARSER_H_