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jsoncpp/src/lib_json/json_reader.cpp
Chen 83946a28db
Ignore byte order mark in the head of UTF-8 text. (#1149) 
* Ignore bom at the beginning of the UTF-8 text
2020-04-28 15:16:05 +08:00

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// Copyright 2007-2011 Baptiste Lepilleur and The JsonCpp Authors
// Copyright (C) 2016 InfoTeCS JSC. All rights reserved.
// Distributed under MIT license, or public domain if desired and
// recognized in your jurisdiction.
// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
#if !defined(JSON_IS_AMALGAMATION)
#include "json_tool.h"
#include <json/assertions.h>
#include <json/reader.h>
#include <json/value.h>
#endif // if !defined(JSON_IS_AMALGAMATION)
#include <cassert>
#include <cstring>
#include <iostream>
#include <istream>
#include <limits>
#include <memory>
#include <set>
#include <sstream>
#include <utility>
#include <cstdio>
#if __cplusplus >= 201103L
#if !defined(sscanf)
#define sscanf std::sscanf
#endif
#endif //__cplusplus
#if defined(_MSC_VER)
#if !defined(_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES)
#define _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES 1
#endif //_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES
#endif //_MSC_VER
#if defined(_MSC_VER)
// Disable warning about strdup being deprecated.
#pragma warning(disable : 4996)
#endif
// Define JSONCPP_DEPRECATED_STACK_LIMIT as an appropriate integer at compile
// time to change the stack limit
#if !defined(JSONCPP_DEPRECATED_STACK_LIMIT)
#define JSONCPP_DEPRECATED_STACK_LIMIT 1000
#endif
static size_t const stackLimit_g =
JSONCPP_DEPRECATED_STACK_LIMIT; // see readValue()
namespace Json {
#if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
using CharReaderPtr = std::unique_ptr<CharReader>;
#else
using CharReaderPtr = std::auto_ptr<CharReader>;
#endif
// Implementation of class Features
// ////////////////////////////////
Features::Features() = default;
Features Features::all() { return {}; }
Features Features::strictMode() {
Features features;
features.allowComments_ = false;
features.strictRoot_ = true;
features.allowDroppedNullPlaceholders_ = false;
features.allowNumericKeys_ = false;
return features;
}
// Implementation of class Reader
// ////////////////////////////////
bool Reader::containsNewLine(Reader::Location begin, Reader::Location end) {
for (; begin < end; ++begin)
if (*begin == '\n' || *begin == '\r')
return true;
return false;
}
// Class Reader
// //////////////////////////////////////////////////////////////////
Reader::Reader() : features_(Features::all()) {}
Reader::Reader(const Features& features) : features_(features) {}
bool Reader::parse(const std::string& document, Value& root,
bool collectComments) {
document_.assign(document.begin(), document.end());
const char* begin = document_.c_str();
const char* end = begin + document_.length();
return parse(begin, end, root, collectComments);
}
bool Reader::parse(std::istream& is, Value& root, bool collectComments) {
// std::istream_iterator<char> begin(is);
// std::istream_iterator<char> end;
// Those would allow streamed input from a file, if parse() were a
// template function.
// Since String is reference-counted, this at least does not
// create an extra copy.
String doc;
std::getline(is, doc, static_cast<char> EOF);
return parse(doc.data(), doc.data() + doc.size(), root, collectComments);
}
bool Reader::parse(const char* beginDoc, const char* endDoc, Value& root,
bool collectComments) {
if (!features_.allowComments_) {
collectComments = false;
}
begin_ = beginDoc;
end_ = endDoc;
collectComments_ = collectComments;
current_ = begin_;
lastValueEnd_ = nullptr;
lastValue_ = nullptr;
commentsBefore_.clear();
errors_.clear();
while (!nodes_.empty())
nodes_.pop();
nodes_.push(&root);
bool successful = readValue();
Token token;
skipCommentTokens(token);
if (collectComments_ && !commentsBefore_.empty())
root.setComment(commentsBefore_, commentAfter);
if (features_.strictRoot_) {
if (!root.isArray() && !root.isObject()) {
// Set error location to start of doc, ideally should be first token found
// in doc
token.type_ = tokenError;
token.start_ = beginDoc;
token.end_ = endDoc;
addError(
"A valid JSON document must be either an array or an object value.",
token);
return false;
}
}
return successful;
}
bool Reader::readValue() {
// readValue() may call itself only if it calls readObject() or ReadArray().
// These methods execute nodes_.push() just before and nodes_.pop)() just
// after calling readValue(). parse() executes one nodes_.push(), so > instead
// of >=.
if (nodes_.size() > stackLimit_g)
throwRuntimeError("Exceeded stackLimit in readValue().");
Token token;
skipCommentTokens(token);
bool successful = true;
if (collectComments_ && !commentsBefore_.empty()) {
currentValue().setComment(commentsBefore_, commentBefore);
commentsBefore_.clear();
}
switch (token.type_) {
case tokenObjectBegin:
successful = readObject(token);
currentValue().setOffsetLimit(current_ - begin_);
break;
case tokenArrayBegin:
successful = readArray(token);
currentValue().setOffsetLimit(current_ - begin_);
break;
case tokenNumber:
successful = decodeNumber(token);
break;
case tokenString:
successful = decodeString(token);
break;
case tokenTrue: {
Value v(true);
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenFalse: {
Value v(false);
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenNull: {
Value v;
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenArraySeparator:
case tokenObjectEnd:
case tokenArrayEnd:
if (features_.allowDroppedNullPlaceholders_) {
// "Un-read" the current token and mark the current value as a null
// token.
current_--;
Value v;
currentValue().swapPayload(v);
currentValue().setOffsetStart(current_ - begin_ - 1);
currentValue().setOffsetLimit(current_ - begin_);
break;
} // Else, fall through...
default:
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
return addError("Syntax error: value, object or array expected.", token);
}
if (collectComments_) {
lastValueEnd_ = current_;
lastValue_ = &currentValue();
}
return successful;
}
void Reader::skipCommentTokens(Token& token) {
if (features_.allowComments_) {
do {
readToken(token);
} while (token.type_ == tokenComment);
} else {
readToken(token);
}
}
bool Reader::readToken(Token& token) {
skipSpaces();
token.start_ = current_;
Char c = getNextChar();
bool ok = true;
switch (c) {
case '{':
token.type_ = tokenObjectBegin;
break;
case '}':
token.type_ = tokenObjectEnd;
break;
case '[':
token.type_ = tokenArrayBegin;
break;
case ']':
token.type_ = tokenArrayEnd;
break;
case '"':
token.type_ = tokenString;
ok = readString();
break;
case '/':
token.type_ = tokenComment;
ok = readComment();
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case '-':
token.type_ = tokenNumber;
readNumber();
break;
case 't':
token.type_ = tokenTrue;
ok = match("rue", 3);
break;
case 'f':
token.type_ = tokenFalse;
ok = match("alse", 4);
break;
case 'n':
token.type_ = tokenNull;
ok = match("ull", 3);
break;
case ',':
token.type_ = tokenArraySeparator;
break;
case ':':
token.type_ = tokenMemberSeparator;
break;
case 0:
token.type_ = tokenEndOfStream;
break;
default:
ok = false;
break;
}
if (!ok)
token.type_ = tokenError;
token.end_ = current_;
return ok;
}
void Reader::skipSpaces() {
while (current_ != end_) {
Char c = *current_;
if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
++current_;
else
break;
}
}
bool Reader::match(const Char* pattern, int patternLength) {
if (end_ - current_ < patternLength)
return false;
int index = patternLength;
while (index--)
if (current_[index] != pattern[index])
return false;
current_ += patternLength;
return true;
}
bool Reader::readComment() {
Location commentBegin = current_ - 1;
Char c = getNextChar();
bool successful = false;
if (c == '*')
successful = readCStyleComment();
else if (c == '/')
successful = readCppStyleComment();
if (!successful)
return false;
if (collectComments_) {
CommentPlacement placement = commentBefore;
if (lastValueEnd_ && !containsNewLine(lastValueEnd_, commentBegin)) {
if (c != '*' || !containsNewLine(commentBegin, current_))
placement = commentAfterOnSameLine;
}
addComment(commentBegin, current_, placement);
}
return true;
}
String Reader::normalizeEOL(Reader::Location begin, Reader::Location end) {
String normalized;
normalized.reserve(static_cast<size_t>(end - begin));
Reader::Location current = begin;
while (current != end) {
char c = *current++;
if (c == '\r') {
if (current != end && *current == '\n')
// convert dos EOL
++current;
// convert Mac EOL
normalized += '\n';
} else {
normalized += c;
}
}
return normalized;
}
void Reader::addComment(Location begin, Location end,
CommentPlacement placement) {
assert(collectComments_);
const String& normalized = normalizeEOL(begin, end);
if (placement == commentAfterOnSameLine) {
assert(lastValue_ != nullptr);
lastValue_->setComment(normalized, placement);
} else {
commentsBefore_ += normalized;
}
}
bool Reader::readCStyleComment() {
while ((current_ + 1) < end_) {
Char c = getNextChar();
if (c == '*' && *current_ == '/')
break;
}
return getNextChar() == '/';
}
bool Reader::readCppStyleComment() {
while (current_ != end_) {
Char c = getNextChar();
if (c == '\n')
break;
if (c == '\r') {
// Consume DOS EOL. It will be normalized in addComment.
if (current_ != end_ && *current_ == '\n')
getNextChar();
// Break on Moc OS 9 EOL.
break;
}
}
return true;
}
void Reader::readNumber() {
Location p = current_;
char c = '0'; // stopgap for already consumed character
// integral part
while (c >= '0' && c <= '9')
c = (current_ = p) < end_ ? *p++ : '\0';
// fractional part
if (c == '.') {
c = (current_ = p) < end_ ? *p++ : '\0';
while (c >= '0' && c <= '9')
c = (current_ = p) < end_ ? *p++ : '\0';
}
// exponential part
if (c == 'e' || c == 'E') {
c = (current_ = p) < end_ ? *p++ : '\0';
if (c == '+' || c == '-')
c = (current_ = p) < end_ ? *p++ : '\0';
while (c >= '0' && c <= '9')
c = (current_ = p) < end_ ? *p++ : '\0';
}
}
bool Reader::readString() {
Char c = '\0';
while (current_ != end_) {
c = getNextChar();
if (c == '\\')
getNextChar();
else if (c == '"')
break;
}
return c == '"';
}
bool Reader::readObject(Token& token) {
Token tokenName;
String name;
Value init(objectValue);
currentValue().swapPayload(init);
currentValue().setOffsetStart(token.start_ - begin_);
while (readToken(tokenName)) {
bool initialTokenOk = true;
while (tokenName.type_ == tokenComment && initialTokenOk)
initialTokenOk = readToken(tokenName);
if (!initialTokenOk)
break;
if (tokenName.type_ == tokenObjectEnd && name.empty()) // empty object
return true;
name.clear();
if (tokenName.type_ == tokenString) {
if (!decodeString(tokenName, name))
return recoverFromError(tokenObjectEnd);
} else if (tokenName.type_ == tokenNumber && features_.allowNumericKeys_) {
Value numberName;
if (!decodeNumber(tokenName, numberName))
return recoverFromError(tokenObjectEnd);
name = numberName.asString();
} else {
break;
}
Token colon;
if (!readToken(colon) || colon.type_ != tokenMemberSeparator) {
return addErrorAndRecover("Missing ':' after object member name", colon,
tokenObjectEnd);
}
Value& value = currentValue()[name];
nodes_.push(&value);
bool ok = readValue();
nodes_.pop();
if (!ok) // error already set
return recoverFromError(tokenObjectEnd);
Token comma;
if (!readToken(comma) ||
(comma.type_ != tokenObjectEnd && comma.type_ != tokenArraySeparator &&
comma.type_ != tokenComment)) {
return addErrorAndRecover("Missing ',' or '}' in object declaration",
comma, tokenObjectEnd);
}
bool finalizeTokenOk = true;
while (comma.type_ == tokenComment && finalizeTokenOk)
finalizeTokenOk = readToken(comma);
if (comma.type_ == tokenObjectEnd)
return true;
}
return addErrorAndRecover("Missing '}' or object member name", tokenName,
tokenObjectEnd);
}
bool Reader::readArray(Token& token) {
Value init(arrayValue);
currentValue().swapPayload(init);
currentValue().setOffsetStart(token.start_ - begin_);
skipSpaces();
if (current_ != end_ && *current_ == ']') // empty array
{
Token endArray;
readToken(endArray);
return true;
}
int index = 0;
for (;;) {
Value& value = currentValue()[index++];
nodes_.push(&value);
bool ok = readValue();
nodes_.pop();
if (!ok) // error already set
return recoverFromError(tokenArrayEnd);
Token currentToken;
// Accept Comment after last item in the array.
ok = readToken(currentToken);
while (currentToken.type_ == tokenComment && ok) {
ok = readToken(currentToken);
}
bool badTokenType = (currentToken.type_ != tokenArraySeparator &&
currentToken.type_ != tokenArrayEnd);
if (!ok || badTokenType) {
return addErrorAndRecover("Missing ',' or ']' in array declaration",
currentToken, tokenArrayEnd);
}
if (currentToken.type_ == tokenArrayEnd)
break;
}
return true;
}
bool Reader::decodeNumber(Token& token) {
Value decoded;
if (!decodeNumber(token, decoded))
return false;
currentValue().swapPayload(decoded);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
return true;
}
bool Reader::decodeNumber(Token& token, Value& decoded) {
// Attempts to parse the number as an integer. If the number is
// larger than the maximum supported value of an integer then
// we decode the number as a double.
Location current = token.start_;
bool isNegative = *current == '-';
if (isNegative)
++current;
// TODO: Help the compiler do the div and mod at compile time or get rid of
// them.
Value::LargestUInt maxIntegerValue =
isNegative ? Value::LargestUInt(Value::maxLargestInt) + 1
: Value::maxLargestUInt;
Value::LargestUInt threshold = maxIntegerValue / 10;
Value::LargestUInt value = 0;
while (current < token.end_) {
Char c = *current++;
if (c < '0' || c > '9')
return decodeDouble(token, decoded);
auto digit(static_cast<Value::UInt>(c - '0'));
if (value >= threshold) {
// We've hit or exceeded the max value divided by 10 (rounded down). If
// a) we've only just touched the limit, b) this is the last digit, and
// c) it's small enough to fit in that rounding delta, we're okay.
// Otherwise treat this number as a double to avoid overflow.
if (value > threshold || current != token.end_ ||
digit > maxIntegerValue % 10) {
return decodeDouble(token, decoded);
}
}
value = value * 10 + digit;
}
if (isNegative && value == maxIntegerValue)
decoded = Value::minLargestInt;
else if (isNegative)
decoded = -Value::LargestInt(value);
else if (value <= Value::LargestUInt(Value::maxInt))
decoded = Value::LargestInt(value);
else
decoded = value;
return true;
}
bool Reader::decodeDouble(Token& token) {
Value decoded;
if (!decodeDouble(token, decoded))
return false;
currentValue().swapPayload(decoded);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
return true;
}
bool Reader::decodeDouble(Token& token, Value& decoded) {
double value = 0;
String buffer(token.start_, token.end_);
IStringStream is(buffer);
if (!(is >> value))
return addError(
"'" + String(token.start_, token.end_) + "' is not a number.", token);
decoded = value;
return true;
}
bool Reader::decodeString(Token& token) {
String decoded_string;
if (!decodeString(token, decoded_string))
return false;
Value decoded(decoded_string);
currentValue().swapPayload(decoded);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
return true;
}
bool Reader::decodeString(Token& token, String& decoded) {
decoded.reserve(static_cast<size_t>(token.end_ - token.start_ - 2));
Location current = token.start_ + 1; // skip '"'
Location end = token.end_ - 1; // do not include '"'
while (current != end) {
Char c = *current++;
if (c == '"')
break;
if (c == '\\') {
if (current == end)
return addError("Empty escape sequence in string", token, current);
Char escape = *current++;
switch (escape) {
case '"':
decoded += '"';
break;
case '/':
decoded += '/';
break;
case '\\':
decoded += '\\';
break;
case 'b':
decoded += '\b';
break;
case 'f':
decoded += '\f';
break;
case 'n':
decoded += '\n';
break;
case 'r':
decoded += '\r';
break;
case 't':
decoded += '\t';
break;
case 'u': {
unsigned int unicode;
if (!decodeUnicodeCodePoint(token, current, end, unicode))
return false;
decoded += codePointToUTF8(unicode);
} break;
default:
return addError("Bad escape sequence in string", token, current);
}
} else {
decoded += c;
}
}
return true;
}
bool Reader::decodeUnicodeCodePoint(Token& token, Location& current,
Location end, unsigned int& unicode) {
if (!decodeUnicodeEscapeSequence(token, current, end, unicode))
return false;
if (unicode >= 0xD800 && unicode <= 0xDBFF) {
// surrogate pairs
if (end - current < 6)
return addError(
"additional six characters expected to parse unicode surrogate pair.",
token, current);
if (*(current++) == '\\' && *(current++) == 'u') {
unsigned int surrogatePair;
if (decodeUnicodeEscapeSequence(token, current, end, surrogatePair)) {
unicode = 0x10000 + ((unicode & 0x3FF) << 10) + (surrogatePair & 0x3FF);
} else
return false;
} else
return addError("expecting another \\u token to begin the second half of "
"a unicode surrogate pair",
token, current);
}
return true;
}
bool Reader::decodeUnicodeEscapeSequence(Token& token, Location& current,
Location end,
unsigned int& ret_unicode) {
if (end - current < 4)
return addError(
"Bad unicode escape sequence in string: four digits expected.", token,
current);
int unicode = 0;
for (int index = 0; index < 4; ++index) {
Char c = *current++;
unicode *= 16;
if (c >= '0' && c <= '9')
unicode += c - '0';
else if (c >= 'a' && c <= 'f')
unicode += c - 'a' + 10;
else if (c >= 'A' && c <= 'F')
unicode += c - 'A' + 10;
else
return addError(
"Bad unicode escape sequence in string: hexadecimal digit expected.",
token, current);
}
ret_unicode = static_cast<unsigned int>(unicode);
return true;
}
bool Reader::addError(const String& message, Token& token, Location extra) {
ErrorInfo info;
info.token_ = token;
info.message_ = message;
info.extra_ = extra;
errors_.push_back(info);
return false;
}
bool Reader::recoverFromError(TokenType skipUntilToken) {
size_t const errorCount = errors_.size();
Token skip;
for (;;) {
if (!readToken(skip))
errors_.resize(errorCount); // discard errors caused by recovery
if (skip.type_ == skipUntilToken || skip.type_ == tokenEndOfStream)
break;
}
errors_.resize(errorCount);
return false;
}
bool Reader::addErrorAndRecover(const String& message, Token& token,
TokenType skipUntilToken) {
addError(message, token);
return recoverFromError(skipUntilToken);
}
Value& Reader::currentValue() { return *(nodes_.top()); }
Reader::Char Reader::getNextChar() {
if (current_ == end_)
return 0;
return *current_++;
}
void Reader::getLocationLineAndColumn(Location location, int& line,
int& column) const {
Location current = begin_;
Location lastLineStart = current;
line = 0;
while (current < location && current != end_) {
Char c = *current++;
if (c == '\r') {
if (*current == '\n')
++current;
lastLineStart = current;
++line;
} else if (c == '\n') {
lastLineStart = current;
++line;
}
}
// column & line start at 1
column = int(location - lastLineStart) + 1;
++line;
}
String Reader::getLocationLineAndColumn(Location location) const {
int line, column;
getLocationLineAndColumn(location, line, column);
char buffer[18 + 16 + 16 + 1];
jsoncpp_snprintf(buffer, sizeof(buffer), "Line %d, Column %d", line, column);
return buffer;
}
// Deprecated. Preserved for backward compatibility
String Reader::getFormatedErrorMessages() const {
return getFormattedErrorMessages();
}
String Reader::getFormattedErrorMessages() const {
String formattedMessage;
for (const auto& error : errors_) {
formattedMessage +=
"* " + getLocationLineAndColumn(error.token_.start_) + "\n";
formattedMessage += " " + error.message_ + "\n";
if (error.extra_)
formattedMessage +=
"See " + getLocationLineAndColumn(error.extra_) + " for detail.\n";
}
return formattedMessage;
}
std::vector<Reader::StructuredError> Reader::getStructuredErrors() const {
std::vector<Reader::StructuredError> allErrors;
for (const auto& error : errors_) {
Reader::StructuredError structured;
structured.offset_start = error.token_.start_ - begin_;
structured.offset_limit = error.token_.end_ - begin_;
structured.message = error.message_;
allErrors.push_back(structured);
}
return allErrors;
}
bool Reader::pushError(const Value& value, const String& message) {
ptrdiff_t const length = end_ - begin_;
if (value.getOffsetStart() > length || value.getOffsetLimit() > length)
return false;
Token token;
token.type_ = tokenError;
token.start_ = begin_ + value.getOffsetStart();
token.end_ = begin_ + value.getOffsetLimit();
ErrorInfo info;
info.token_ = token;
info.message_ = message;
info.extra_ = nullptr;
errors_.push_back(info);
return true;
}
bool Reader::pushError(const Value& value, const String& message,
const Value& extra) {
ptrdiff_t const length = end_ - begin_;
if (value.getOffsetStart() > length || value.getOffsetLimit() > length ||
extra.getOffsetLimit() > length)
return false;
Token token;
token.type_ = tokenError;
token.start_ = begin_ + value.getOffsetStart();
token.end_ = begin_ + value.getOffsetLimit();
ErrorInfo info;
info.token_ = token;
info.message_ = message;
info.extra_ = begin_ + extra.getOffsetStart();
errors_.push_back(info);
return true;
}
bool Reader::good() const { return errors_.empty(); }
// Originally copied from the Features class (now deprecated), used internally
// for features implementation.
class OurFeatures {
public:
static OurFeatures all();
bool allowComments_;
bool allowTrailingCommas_;
bool strictRoot_;
bool allowDroppedNullPlaceholders_;
bool allowNumericKeys_;
bool allowSingleQuotes_;
bool failIfExtra_;
bool rejectDupKeys_;
bool allowSpecialFloats_;
bool allowBom_;
size_t stackLimit_;
}; // OurFeatures
OurFeatures OurFeatures::all() { return {}; }
// Implementation of class Reader
// ////////////////////////////////
// Originally copied from the Reader class (now deprecated), used internally
// for implementing JSON reading.
class OurReader {
public:
using Char = char;
using Location = const Char*;
struct StructuredError {
ptrdiff_t offset_start;
ptrdiff_t offset_limit;
String message;
};
explicit OurReader(OurFeatures const& features);
bool parse(const char* beginDoc, const char* endDoc, Value& root,
bool collectComments = true);
String getFormattedErrorMessages() const;
std::vector<StructuredError> getStructuredErrors() const;
private:
OurReader(OurReader const&); // no impl
void operator=(OurReader const&); // no impl
enum TokenType {
tokenEndOfStream = 0,
tokenObjectBegin,
tokenObjectEnd,
tokenArrayBegin,
tokenArrayEnd,
tokenString,
tokenNumber,
tokenTrue,
tokenFalse,
tokenNull,
tokenNaN,
tokenPosInf,
tokenNegInf,
tokenArraySeparator,
tokenMemberSeparator,
tokenComment,
tokenError
};
class Token {
public:
TokenType type_;
Location start_;
Location end_;
};
class ErrorInfo {
public:
Token token_;
String message_;
Location extra_;
};
using Errors = std::deque<ErrorInfo>;
bool readToken(Token& token);
void skipSpaces();
void skipBom(bool allowBom);
bool match(const Char* pattern, int patternLength);
bool readComment();
bool readCStyleComment(bool* containsNewLineResult);
bool readCppStyleComment();
bool readString();
bool readStringSingleQuote();
bool readNumber(bool checkInf);
bool readValue();
bool readObject(Token& token);
bool readArray(Token& token);
bool decodeNumber(Token& token);
bool decodeNumber(Token& token, Value& decoded);
bool decodeString(Token& token);
bool decodeString(Token& token, String& decoded);
bool decodeDouble(Token& token);
bool decodeDouble(Token& token, Value& decoded);
bool decodeUnicodeCodePoint(Token& token, Location& current, Location end,
unsigned int& unicode);
bool decodeUnicodeEscapeSequence(Token& token, Location& current,
Location end, unsigned int& unicode);
bool addError(const String& message, Token& token, Location extra = nullptr);
bool recoverFromError(TokenType skipUntilToken);
bool addErrorAndRecover(const String& message, Token& token,
TokenType skipUntilToken);
void skipUntilSpace();
Value& currentValue();
Char getNextChar();
void getLocationLineAndColumn(Location location, int& line,
int& column) const;
String getLocationLineAndColumn(Location location) const;
void addComment(Location begin, Location end, CommentPlacement placement);
void skipCommentTokens(Token& token);
static String normalizeEOL(Location begin, Location end);
static bool containsNewLine(Location begin, Location end);
using Nodes = std::stack<Value*>;
Nodes nodes_{};
Errors errors_{};
String document_{};
Location begin_ = nullptr;
Location end_ = nullptr;
Location current_ = nullptr;
Location lastValueEnd_ = nullptr;
Value* lastValue_ = nullptr;
bool lastValueHasAComment_ = false;
String commentsBefore_{};
OurFeatures const features_;
bool collectComments_ = false;
}; // OurReader
// complete copy of Read impl, for OurReader
bool OurReader::containsNewLine(OurReader::Location begin,
OurReader::Location end) {
for (; begin < end; ++begin)
if (*begin == '\n' || *begin == '\r')
return true;
return false;
}
OurReader::OurReader(OurFeatures const& features) : features_(features) {}
bool OurReader::parse(const char* beginDoc, const char* endDoc, Value& root,
bool collectComments) {
if (!features_.allowComments_) {
collectComments = false;
}
begin_ = beginDoc;
end_ = endDoc;
collectComments_ = collectComments;
current_ = begin_;
lastValueEnd_ = nullptr;
lastValue_ = nullptr;
commentsBefore_.clear();
errors_.clear();
while (!nodes_.empty())
nodes_.pop();
nodes_.push(&root);
// skip byte order mark if it exists at the beginning of the UTF-8 text.
skipBom(features_.allowBom_);
bool successful = readValue();
nodes_.pop();
Token token;
skipCommentTokens(token);
if (features_.failIfExtra_ && (token.type_ != tokenEndOfStream)) {
addError("Extra non-whitespace after JSON value.", token);
return false;
}
if (collectComments_ && !commentsBefore_.empty())
root.setComment(commentsBefore_, commentAfter);
if (features_.strictRoot_) {
if (!root.isArray() && !root.isObject()) {
// Set error location to start of doc, ideally should be first token found
// in doc
token.type_ = tokenError;
token.start_ = beginDoc;
token.end_ = endDoc;
addError(
"A valid JSON document must be either an array or an object value.",
token);
return false;
}
}
return successful;
}
bool OurReader::readValue() {
// To preserve the old behaviour we cast size_t to int.
if (nodes_.size() > features_.stackLimit_)
throwRuntimeError("Exceeded stackLimit in readValue().");
Token token;
skipCommentTokens(token);
bool successful = true;
if (collectComments_ && !commentsBefore_.empty()) {
currentValue().setComment(commentsBefore_, commentBefore);
commentsBefore_.clear();
}
switch (token.type_) {
case tokenObjectBegin:
successful = readObject(token);
currentValue().setOffsetLimit(current_ - begin_);
break;
case tokenArrayBegin:
successful = readArray(token);
currentValue().setOffsetLimit(current_ - begin_);
break;
case tokenNumber:
successful = decodeNumber(token);
break;
case tokenString:
successful = decodeString(token);
break;
case tokenTrue: {
Value v(true);
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenFalse: {
Value v(false);
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenNull: {
Value v;
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenNaN: {
Value v(std::numeric_limits<double>::quiet_NaN());
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenPosInf: {
Value v(std::numeric_limits<double>::infinity());
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenNegInf: {
Value v(-std::numeric_limits<double>::infinity());
currentValue().swapPayload(v);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
} break;
case tokenArraySeparator:
case tokenObjectEnd:
case tokenArrayEnd:
if (features_.allowDroppedNullPlaceholders_) {
// "Un-read" the current token and mark the current value as a null
// token.
current_--;
Value v;
currentValue().swapPayload(v);
currentValue().setOffsetStart(current_ - begin_ - 1);
currentValue().setOffsetLimit(current_ - begin_);
break;
} // else, fall through ...
default:
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
return addError("Syntax error: value, object or array expected.", token);
}
if (collectComments_) {
lastValueEnd_ = current_;
lastValueHasAComment_ = false;
lastValue_ = &currentValue();
}
return successful;
}
void OurReader::skipCommentTokens(Token& token) {
if (features_.allowComments_) {
do {
readToken(token);
} while (token.type_ == tokenComment);
} else {
readToken(token);
}
}
bool OurReader::readToken(Token& token) {
skipSpaces();
token.start_ = current_;
Char c = getNextChar();
bool ok = true;
switch (c) {
case '{':
token.type_ = tokenObjectBegin;
break;
case '}':
token.type_ = tokenObjectEnd;
break;
case '[':
token.type_ = tokenArrayBegin;
break;
case ']':
token.type_ = tokenArrayEnd;
break;
case '"':
token.type_ = tokenString;
ok = readString();
break;
case '\'':
if (features_.allowSingleQuotes_) {
token.type_ = tokenString;
ok = readStringSingleQuote();
break;
} // else fall through
case '/':
token.type_ = tokenComment;
ok = readComment();
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
token.type_ = tokenNumber;
readNumber(false);
break;
case '-':
if (readNumber(true)) {
token.type_ = tokenNumber;
} else {
token.type_ = tokenNegInf;
ok = features_.allowSpecialFloats_ && match("nfinity", 7);
}
break;
case '+':
if (readNumber(true)) {
token.type_ = tokenNumber;
} else {
token.type_ = tokenPosInf;
ok = features_.allowSpecialFloats_ && match("nfinity", 7);
}
break;
case 't':
token.type_ = tokenTrue;
ok = match("rue", 3);
break;
case 'f':
token.type_ = tokenFalse;
ok = match("alse", 4);
break;
case 'n':
token.type_ = tokenNull;
ok = match("ull", 3);
break;
case 'N':
if (features_.allowSpecialFloats_) {
token.type_ = tokenNaN;
ok = match("aN", 2);
} else {
ok = false;
}
break;
case 'I':
if (features_.allowSpecialFloats_) {
token.type_ = tokenPosInf;
ok = match("nfinity", 7);
} else {
ok = false;
}
break;
case ',':
token.type_ = tokenArraySeparator;
break;
case ':':
token.type_ = tokenMemberSeparator;
break;
case 0:
token.type_ = tokenEndOfStream;
break;
default:
ok = false;
break;
}
if (!ok)
token.type_ = tokenError;
token.end_ = current_;
return ok;
}
void OurReader::skipSpaces() {
while (current_ != end_) {
Char c = *current_;
if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
++current_;
else
break;
}
}
void OurReader::skipBom(bool allowBom) {
// If BOM is not allowed, then skip it.
// The default value is: false
if (!allowBom) {
if (strncmp(begin_, "\xEF\xBB\xBF", 3) == 0) {
begin_ += 3;
current_ = begin_;
}
}
}
bool OurReader::match(const Char* pattern, int patternLength) {
if (end_ - current_ < patternLength)
return false;
int index = patternLength;
while (index--)
if (current_[index] != pattern[index])
return false;
current_ += patternLength;
return true;
}
bool OurReader::readComment() {
const Location commentBegin = current_ - 1;
const Char c = getNextChar();
bool successful = false;
bool cStyleWithEmbeddedNewline = false;
const bool isCStyleComment = (c == '*');
const bool isCppStyleComment = (c == '/');
if (isCStyleComment) {
successful = readCStyleComment(&cStyleWithEmbeddedNewline);
} else if (isCppStyleComment) {
successful = readCppStyleComment();
}
if (!successful)
return false;
if (collectComments_) {
CommentPlacement placement = commentBefore;
if (!lastValueHasAComment_) {
if (lastValueEnd_ && !containsNewLine(lastValueEnd_, commentBegin)) {
if (isCppStyleComment || !cStyleWithEmbeddedNewline) {
placement = commentAfterOnSameLine;
lastValueHasAComment_ = true;
}
}
}
addComment(commentBegin, current_, placement);
}
return true;
}
String OurReader::normalizeEOL(OurReader::Location begin,
OurReader::Location end) {
String normalized;
normalized.reserve(static_cast<size_t>(end - begin));
OurReader::Location current = begin;
while (current != end) {
char c = *current++;
if (c == '\r') {
if (current != end && *current == '\n')
// convert dos EOL
++current;
// convert Mac EOL
normalized += '\n';
} else {
normalized += c;
}
}
return normalized;
}
void OurReader::addComment(Location begin, Location end,
CommentPlacement placement) {
assert(collectComments_);
const String& normalized = normalizeEOL(begin, end);
if (placement == commentAfterOnSameLine) {
assert(lastValue_ != nullptr);
lastValue_->setComment(normalized, placement);
} else {
commentsBefore_ += normalized;
}
}
bool OurReader::readCStyleComment(bool* containsNewLineResult) {
*containsNewLineResult = false;
while ((current_ + 1) < end_) {
Char c = getNextChar();
if (c == '*' && *current_ == '/')
break;
if (c == '\n')
*containsNewLineResult = true;
}
return getNextChar() == '/';
}
bool OurReader::readCppStyleComment() {
while (current_ != end_) {
Char c = getNextChar();
if (c == '\n')
break;
if (c == '\r') {
// Consume DOS EOL. It will be normalized in addComment.
if (current_ != end_ && *current_ == '\n')
getNextChar();
// Break on Moc OS 9 EOL.
break;
}
}
return true;
}
bool OurReader::readNumber(bool checkInf) {
Location p = current_;
if (checkInf && p != end_ && *p == 'I') {
current_ = ++p;
return false;
}
char c = '0'; // stopgap for already consumed character
// integral part
while (c >= '0' && c <= '9')
c = (current_ = p) < end_ ? *p++ : '\0';
// fractional part
if (c == '.') {
c = (current_ = p) < end_ ? *p++ : '\0';
while (c >= '0' && c <= '9')
c = (current_ = p) < end_ ? *p++ : '\0';
}
// exponential part
if (c == 'e' || c == 'E') {
c = (current_ = p) < end_ ? *p++ : '\0';
if (c == '+' || c == '-')
c = (current_ = p) < end_ ? *p++ : '\0';
while (c >= '0' && c <= '9')
c = (current_ = p) < end_ ? *p++ : '\0';
}
return true;
}
bool OurReader::readString() {
Char c = 0;
while (current_ != end_) {
c = getNextChar();
if (c == '\\')
getNextChar();
else if (c == '"')
break;
}
return c == '"';
}
bool OurReader::readStringSingleQuote() {
Char c = 0;
while (current_ != end_) {
c = getNextChar();
if (c == '\\')
getNextChar();
else if (c == '\'')
break;
}
return c == '\'';
}
bool OurReader::readObject(Token& token) {
Token tokenName;
String name;
Value init(objectValue);
currentValue().swapPayload(init);
currentValue().setOffsetStart(token.start_ - begin_);
while (readToken(tokenName)) {
bool initialTokenOk = true;
while (tokenName.type_ == tokenComment && initialTokenOk)
initialTokenOk = readToken(tokenName);
if (!initialTokenOk)
break;
if (tokenName.type_ == tokenObjectEnd &&
(name.empty() ||
features_.allowTrailingCommas_)) // empty object or trailing comma
return true;
name.clear();
if (tokenName.type_ == tokenString) {
if (!decodeString(tokenName, name))
return recoverFromError(tokenObjectEnd);
} else if (tokenName.type_ == tokenNumber && features_.allowNumericKeys_) {
Value numberName;
if (!decodeNumber(tokenName, numberName))
return recoverFromError(tokenObjectEnd);
name = numberName.asString();
} else {
break;
}
if (name.length() >= (1U << 30))
throwRuntimeError("keylength >= 2^30");
if (features_.rejectDupKeys_ && currentValue().isMember(name)) {
String msg = "Duplicate key: '" + name + "'";
return addErrorAndRecover(msg, tokenName, tokenObjectEnd);
}
Token colon;
if (!readToken(colon) || colon.type_ != tokenMemberSeparator) {
return addErrorAndRecover("Missing ':' after object member name", colon,
tokenObjectEnd);
}
Value& value = currentValue()[name];
nodes_.push(&value);
bool ok = readValue();
nodes_.pop();
if (!ok) // error already set
return recoverFromError(tokenObjectEnd);
Token comma;
if (!readToken(comma) ||
(comma.type_ != tokenObjectEnd && comma.type_ != tokenArraySeparator &&
comma.type_ != tokenComment)) {
return addErrorAndRecover("Missing ',' or '}' in object declaration",
comma, tokenObjectEnd);
}
bool finalizeTokenOk = true;
while (comma.type_ == tokenComment && finalizeTokenOk)
finalizeTokenOk = readToken(comma);
if (comma.type_ == tokenObjectEnd)
return true;
}
return addErrorAndRecover("Missing '}' or object member name", tokenName,
tokenObjectEnd);
}
bool OurReader::readArray(Token& token) {
Value init(arrayValue);
currentValue().swapPayload(init);
currentValue().setOffsetStart(token.start_ - begin_);
int index = 0;
for (;;) {
skipSpaces();
if (current_ != end_ && *current_ == ']' &&
(index == 0 ||
(features_.allowTrailingCommas_ &&
!features_.allowDroppedNullPlaceholders_))) // empty array or trailing
// comma
{
Token endArray;
readToken(endArray);
return true;
}
Value& value = currentValue()[index++];
nodes_.push(&value);
bool ok = readValue();
nodes_.pop();
if (!ok) // error already set
return recoverFromError(tokenArrayEnd);
Token currentToken;
// Accept Comment after last item in the array.
ok = readToken(currentToken);
while (currentToken.type_ == tokenComment && ok) {
ok = readToken(currentToken);
}
bool badTokenType = (currentToken.type_ != tokenArraySeparator &&
currentToken.type_ != tokenArrayEnd);
if (!ok || badTokenType) {
return addErrorAndRecover("Missing ',' or ']' in array declaration",
currentToken, tokenArrayEnd);
}
if (currentToken.type_ == tokenArrayEnd)
break;
}
return true;
}
bool OurReader::decodeNumber(Token& token) {
Value decoded;
if (!decodeNumber(token, decoded))
return false;
currentValue().swapPayload(decoded);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
return true;
}
bool OurReader::decodeNumber(Token& token, Value& decoded) {
// Attempts to parse the number as an integer. If the number is
// larger than the maximum supported value of an integer then
// we decode the number as a double.
Location current = token.start_;
const bool isNegative = *current == '-';
if (isNegative) {
++current;
}
// We assume we can represent the largest and smallest integer types as
// unsigned integers with separate sign. This is only true if they can fit
// into an unsigned integer.
static_assert(Value::maxLargestInt <= Value::maxLargestUInt,
"Int must be smaller than UInt");
// We need to convert minLargestInt into a positive number. The easiest way
// to do this conversion is to assume our "threshold" value of minLargestInt
// divided by 10 can fit in maxLargestInt when absolute valued. This should
// be a safe assumption.
static_assert(Value::minLargestInt <= -Value::maxLargestInt,
"The absolute value of minLargestInt must be greater than or "
"equal to maxLargestInt");
static_assert(Value::minLargestInt / 10 >= -Value::maxLargestInt,
"The absolute value of minLargestInt must be only 1 magnitude "
"larger than maxLargest Int");
static constexpr Value::LargestUInt positive_threshold =
Value::maxLargestUInt / 10;
static constexpr Value::UInt positive_last_digit = Value::maxLargestUInt % 10;
// For the negative values, we have to be more careful. Since typically
// -Value::minLargestInt will cause an overflow, we first divide by 10 and
// then take the inverse. This assumes that minLargestInt is only a single
// power of 10 different in magnitude, which we check above. For the last
// digit, we take the modulus before negating for the same reason.
static constexpr auto negative_threshold =
Value::LargestUInt(-(Value::minLargestInt / 10));
static constexpr auto negative_last_digit =
Value::UInt(-(Value::minLargestInt % 10));
const Value::LargestUInt threshold =
isNegative ? negative_threshold : positive_threshold;
const Value::UInt max_last_digit =
isNegative ? negative_last_digit : positive_last_digit;
Value::LargestUInt value = 0;
while (current < token.end_) {
Char c = *current++;
if (c < '0' || c > '9')
return decodeDouble(token, decoded);
const auto digit(static_cast<Value::UInt>(c - '0'));
if (value >= threshold) {
// We've hit or exceeded the max value divided by 10 (rounded down). If
// a) we've only just touched the limit, meaing value == threshold,
// b) this is the last digit, or
// c) it's small enough to fit in that rounding delta, we're okay.
// Otherwise treat this number as a double to avoid overflow.
if (value > threshold || current != token.end_ ||
digit > max_last_digit) {
return decodeDouble(token, decoded);
}
}
value = value * 10 + digit;
}
if (isNegative) {
// We use the same magnitude assumption here, just in case.
const auto last_digit = static_cast<Value::UInt>(value % 10);
decoded = -Value::LargestInt(value / 10) * 10 - last_digit;
} else if (value <= Value::LargestUInt(Value::maxLargestInt)) {
decoded = Value::LargestInt(value);
} else {
decoded = value;
}
return true;
}
bool OurReader::decodeDouble(Token& token) {
Value decoded;
if (!decodeDouble(token, decoded))
return false;
currentValue().swapPayload(decoded);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
return true;
}
bool OurReader::decodeDouble(Token& token, Value& decoded) {
double value = 0;
const String buffer(token.start_, token.end_);
IStringStream is(buffer);
if (!(is >> value)) {
return addError(
"'" + String(token.start_, token.end_) + "' is not a number.", token);
}
decoded = value;
return true;
}
bool OurReader::decodeString(Token& token) {
String decoded_string;
if (!decodeString(token, decoded_string))
return false;
Value decoded(decoded_string);
currentValue().swapPayload(decoded);
currentValue().setOffsetStart(token.start_ - begin_);
currentValue().setOffsetLimit(token.end_ - begin_);
return true;
}
bool OurReader::decodeString(Token& token, String& decoded) {
decoded.reserve(static_cast<size_t>(token.end_ - token.start_ - 2));
Location current = token.start_ + 1; // skip '"'
Location end = token.end_ - 1; // do not include '"'
while (current != end) {
Char c = *current++;
if (c == '"')
break;
if (c == '\\') {
if (current == end)
return addError("Empty escape sequence in string", token, current);
Char escape = *current++;
switch (escape) {
case '"':
decoded += '"';
break;
case '/':
decoded += '/';
break;
case '\\':
decoded += '\\';
break;
case 'b':
decoded += '\b';
break;
case 'f':
decoded += '\f';
break;
case 'n':
decoded += '\n';
break;
case 'r':
decoded += '\r';
break;
case 't':
decoded += '\t';
break;
case 'u': {
unsigned int unicode;
if (!decodeUnicodeCodePoint(token, current, end, unicode))
return false;
decoded += codePointToUTF8(unicode);
} break;
default:
return addError("Bad escape sequence in string", token, current);
}
} else {
decoded += c;
}
}
return true;
}
bool OurReader::decodeUnicodeCodePoint(Token& token, Location& current,
Location end, unsigned int& unicode) {
if (!decodeUnicodeEscapeSequence(token, current, end, unicode))
return false;
if (unicode >= 0xD800 && unicode <= 0xDBFF) {
// surrogate pairs
if (end - current < 6)
return addError(
"additional six characters expected to parse unicode surrogate pair.",
token, current);
if (*(current++) == '\\' && *(current++) == 'u') {
unsigned int surrogatePair;
if (decodeUnicodeEscapeSequence(token, current, end, surrogatePair)) {
unicode = 0x10000 + ((unicode & 0x3FF) << 10) + (surrogatePair & 0x3FF);
} else
return false;
} else
return addError("expecting another \\u token to begin the second half of "
"a unicode surrogate pair",
token, current);
}
return true;
}
bool OurReader::decodeUnicodeEscapeSequence(Token& token, Location& current,
Location end,
unsigned int& ret_unicode) {
if (end - current < 4)
return addError(
"Bad unicode escape sequence in string: four digits expected.", token,
current);
int unicode = 0;
for (int index = 0; index < 4; ++index) {
Char c = *current++;
unicode *= 16;
if (c >= '0' && c <= '9')
unicode += c - '0';
else if (c >= 'a' && c <= 'f')
unicode += c - 'a' + 10;
else if (c >= 'A' && c <= 'F')
unicode += c - 'A' + 10;
else
return addError(
"Bad unicode escape sequence in string: hexadecimal digit expected.",
token, current);
}
ret_unicode = static_cast<unsigned int>(unicode);
return true;
}
bool OurReader::addError(const String& message, Token& token, Location extra) {
ErrorInfo info;
info.token_ = token;
info.message_ = message;
info.extra_ = extra;
errors_.push_back(info);
return false;
}
bool OurReader::recoverFromError(TokenType skipUntilToken) {
size_t errorCount = errors_.size();
Token skip;
for (;;) {
if (!readToken(skip))
errors_.resize(errorCount); // discard errors caused by recovery
if (skip.type_ == skipUntilToken || skip.type_ == tokenEndOfStream)
break;
}
errors_.resize(errorCount);
return false;
}
bool OurReader::addErrorAndRecover(const String& message, Token& token,
TokenType skipUntilToken) {
addError(message, token);
return recoverFromError(skipUntilToken);
}
Value& OurReader::currentValue() { return *(nodes_.top()); }
OurReader::Char OurReader::getNextChar() {
if (current_ == end_)
return 0;
return *current_++;
}
void OurReader::getLocationLineAndColumn(Location location, int& line,
int& column) const {
Location current = begin_;
Location lastLineStart = current;
line = 0;
while (current < location && current != end_) {
Char c = *current++;
if (c == '\r') {
if (*current == '\n')
++current;
lastLineStart = current;
++line;
} else if (c == '\n') {
lastLineStart = current;
++line;
}
}
// column & line start at 1
column = int(location - lastLineStart) + 1;
++line;
}
String OurReader::getLocationLineAndColumn(Location location) const {
int line, column;
getLocationLineAndColumn(location, line, column);
char buffer[18 + 16 + 16 + 1];
jsoncpp_snprintf(buffer, sizeof(buffer), "Line %d, Column %d", line, column);
return buffer;
}
String OurReader::getFormattedErrorMessages() const {
String formattedMessage;
for (const auto& error : errors_) {
formattedMessage +=
"* " + getLocationLineAndColumn(error.token_.start_) + "\n";
formattedMessage += " " + error.message_ + "\n";
if (error.extra_)
formattedMessage +=
"See " + getLocationLineAndColumn(error.extra_) + " for detail.\n";
}
return formattedMessage;
}
std::vector<OurReader::StructuredError> OurReader::getStructuredErrors() const {
std::vector<OurReader::StructuredError> allErrors;
for (const auto& error : errors_) {
OurReader::StructuredError structured;
structured.offset_start = error.token_.start_ - begin_;
structured.offset_limit = error.token_.end_ - begin_;
structured.message = error.message_;
allErrors.push_back(structured);
}
return allErrors;
}
class OurCharReader : public CharReader {
bool const collectComments_;
OurReader reader_;
public:
OurCharReader(bool collectComments, OurFeatures const& features)
: collectComments_(collectComments), reader_(features) {}
bool parse(char const* beginDoc, char const* endDoc, Value* root,
String* errs) override {
bool ok = reader_.parse(beginDoc, endDoc, *root, collectComments_);
if (errs) {
*errs = reader_.getFormattedErrorMessages();
}
return ok;
}
};
CharReaderBuilder::CharReaderBuilder() { setDefaults(&settings_); }
CharReaderBuilder::~CharReaderBuilder() = default;
CharReader* CharReaderBuilder::newCharReader() const {
bool collectComments = settings_["collectComments"].asBool();
OurFeatures features = OurFeatures::all();
features.allowComments_ = settings_["allowComments"].asBool();
features.allowTrailingCommas_ = settings_["allowTrailingCommas"].asBool();
features.strictRoot_ = settings_["strictRoot"].asBool();
features.allowDroppedNullPlaceholders_ =
settings_["allowDroppedNullPlaceholders"].asBool();
features.allowNumericKeys_ = settings_["allowNumericKeys"].asBool();
features.allowSingleQuotes_ = settings_["allowSingleQuotes"].asBool();
// Stack limit is always a size_t, so we get this as an unsigned int
// regardless of it we have 64-bit integer support enabled.
features.stackLimit_ = static_cast<size_t>(settings_["stackLimit"].asUInt());
features.failIfExtra_ = settings_["failIfExtra"].asBool();
features.rejectDupKeys_ = settings_["rejectDupKeys"].asBool();
features.allowSpecialFloats_ = settings_["allowSpecialFloats"].asBool();
features.allowBom_ = settings_["allowBom"].asBool();
return new OurCharReader(collectComments, features);
}
static void getValidReaderKeys(std::set<String>* valid_keys) {
valid_keys->clear();
valid_keys->insert("collectComments");
valid_keys->insert("allowComments");
valid_keys->insert("allowTrailingCommas");
valid_keys->insert("strictRoot");
valid_keys->insert("allowDroppedNullPlaceholders");
valid_keys->insert("allowNumericKeys");
valid_keys->insert("allowSingleQuotes");
valid_keys->insert("stackLimit");
valid_keys->insert("failIfExtra");
valid_keys->insert("rejectDupKeys");
valid_keys->insert("allowSpecialFloats");
valid_keys->insert("allowBom");
}
bool CharReaderBuilder::validate(Json::Value* invalid) const {
Json::Value my_invalid;
if (!invalid)
invalid = &my_invalid; // so we do not need to test for NULL
Json::Value& inv = *invalid;
std::set<String> valid_keys;
getValidReaderKeys(&valid_keys);
Value::Members keys = settings_.getMemberNames();
size_t n = keys.size();
for (size_t i = 0; i < n; ++i) {
String const& key = keys[i];
if (valid_keys.find(key) == valid_keys.end()) {
inv[key] = settings_[key];
}
}
return inv.empty();
}
Value& CharReaderBuilder::operator[](const String& key) {
return settings_[key];
}
// static
void CharReaderBuilder::strictMode(Json::Value* settings) {
//! [CharReaderBuilderStrictMode]
(*settings)["allowComments"] = false;
(*settings)["allowTrailingCommas"] = false;
(*settings)["strictRoot"] = true;
(*settings)["allowDroppedNullPlaceholders"] = false;
(*settings)["allowNumericKeys"] = false;
(*settings)["allowSingleQuotes"] = false;
(*settings)["stackLimit"] = 1000;
(*settings)["failIfExtra"] = true;
(*settings)["rejectDupKeys"] = true;
(*settings)["allowSpecialFloats"] = false;
(*settings)["allowBom"] = false;
//! [CharReaderBuilderStrictMode]
}
// static
void CharReaderBuilder::setDefaults(Json::Value* settings) {
//! [CharReaderBuilderDefaults]
(*settings)["collectComments"] = true;
(*settings)["allowComments"] = true;
(*settings)["allowTrailingCommas"] = true;
(*settings)["strictRoot"] = false;
(*settings)["allowDroppedNullPlaceholders"] = false;
(*settings)["allowNumericKeys"] = false;
(*settings)["allowSingleQuotes"] = false;
(*settings)["stackLimit"] = 1000;
(*settings)["failIfExtra"] = false;
(*settings)["rejectDupKeys"] = false;
(*settings)["allowSpecialFloats"] = false;
(*settings)["allowBom"] = false;
//! [CharReaderBuilderDefaults]
}
//////////////////////////////////
// global functions
bool parseFromStream(CharReader::Factory const& fact, IStream& sin, Value* root,
String* errs) {
OStringStream ssin;
ssin << sin.rdbuf();
String doc = ssin.str();
char const* begin = doc.data();
char const* end = begin + doc.size();
// Note that we do not actually need a null-terminator.
CharReaderPtr const reader(fact.newCharReader());
return reader->parse(begin, end, root, errs);
}
IStream& operator>>(IStream& sin, Value& root) {
CharReaderBuilder b;
String errs;
bool ok = parseFromStream(b, sin, &root, &errs);
if (!ok) {
throwRuntimeError(errs);
}
return sin;
}
} // namespace Json
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