Greg Clayton 98424c4460 Make the "lldb/Utility/JSON.h" able to parse JSON into tokens with the new JSONParser class.
Change over existing code to use this new parser so StructuredData can use the tokenizer to parse JSON instead of doing it manually.

This allowed us to easily parse JSON into JSON* objects as well as into StructuredData.

llvm-svn: 241522
2015-07-06 23:40:40 +00:00

652 lines
18 KiB
C++

//===--------------------- JSON.cpp -----------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/JSON.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Host/StringConvert.h"
using namespace lldb_private;
std::string
JSONString::json_string_quote_metachars (const std::string &s)
{
if (s.find('"') == std::string::npos)
return s;
std::string output;
const size_t s_size = s.size();
const char *s_chars = s.c_str();
for (size_t i = 0; i < s_size; i++)
{
unsigned char ch = *(s_chars + i);
if (ch == '"')
{
output.push_back ('\\');
}
output.push_back (ch);
}
return output;
}
JSONString::JSONString () :
JSONValue(JSONValue::Kind::String),
m_data()
{
}
JSONString::JSONString (const char* s) :
JSONValue(JSONValue::Kind::String),
m_data(s ? s : "")
{
}
JSONString::JSONString (const std::string& s) :
JSONValue(JSONValue::Kind::String),
m_data(s)
{
}
void
JSONString::Write (Stream& s)
{
s.Printf("\"%s\"", json_string_quote_metachars(m_data).c_str());
}
JSONNumber::JSONNumber () :
JSONValue(JSONValue::Kind::Number),
m_is_integer(true),
m_data(0),
m_double(0.0)
{
}
JSONNumber::JSONNumber (uint64_t i) :
JSONValue(JSONValue::Kind::Number),
m_is_integer(true),
m_data(i),
m_double(0.0)
{
}
JSONNumber::JSONNumber (double d) :
JSONValue(JSONValue::Kind::Number),
m_is_integer(false),
m_data(0),
m_double(d)
{
}
void
JSONNumber::Write (Stream& s)
{
if (m_is_integer)
s.Printf("%" PRIu64, m_data);
else
s.Printf("%g", m_double);
}
JSONTrue::JSONTrue () :
JSONValue(JSONValue::Kind::True)
{
}
void
JSONTrue::Write(Stream& s)
{
s.Printf("true");
}
JSONFalse::JSONFalse () :
JSONValue(JSONValue::Kind::False)
{
}
void
JSONFalse::Write(Stream& s)
{
s.Printf("false");
}
JSONNull::JSONNull () :
JSONValue(JSONValue::Kind::Null)
{
}
void
JSONNull::Write(Stream& s)
{
s.Printf("null");
}
JSONObject::JSONObject () :
JSONValue(JSONValue::Kind::Object)
{
}
void
JSONObject::Write (Stream& s)
{
bool first = true;
s.PutChar('{');
auto iter = m_elements.begin(), end = m_elements.end();
for (;iter != end; iter++)
{
if (first)
first = false;
else
s.PutChar(',');
JSONString key(iter->first);
JSONValue::SP value(iter->second);
key.Write(s);
s.PutChar(':');
value->Write(s);
}
s.PutChar('}');
}
bool
JSONObject::SetObject (const std::string& key,
JSONValue::SP value)
{
if (key.empty() || nullptr == value.get())
return false;
m_elements[key] = value;
return true;
}
JSONValue::SP
JSONObject::GetObject (const std::string& key)
{
auto iter = m_elements.find(key), end = m_elements.end();
if (iter == end)
return JSONValue::SP();
return iter->second;
}
JSONArray::JSONArray () :
JSONValue(JSONValue::Kind::Array)
{
}
void
JSONArray::Write (Stream& s)
{
bool first = true;
s.PutChar('[');
auto iter = m_elements.begin(), end = m_elements.end();
for (;iter != end; iter++)
{
if (first)
first = false;
else
s.PutChar(',');
(*iter)->Write(s);
}
s.PutChar(']');
}
bool
JSONArray::SetObject (Index i,
JSONValue::SP value)
{
if (value.get() == nullptr)
return false;
if (i < m_elements.size())
{
m_elements[i] = value;
return true;
}
if (i == m_elements.size())
{
m_elements.push_back(value);
return true;
}
return false;
}
bool
JSONArray::AppendObject (JSONValue::SP value)
{
if (value.get() == nullptr)
return false;
m_elements.push_back(value);
return true;
}
JSONValue::SP
JSONArray::GetObject (Index i)
{
if (i < m_elements.size())
return m_elements[i];
return JSONValue::SP();
}
JSONArray::Size
JSONArray::GetNumElements ()
{
return m_elements.size();
}
JSONParser::JSONParser (const char *cstr) :
StringExtractor(cstr)
{
}
JSONParser::Token
JSONParser::GetToken (std::string &value)
{
StreamString error;
value.clear();
SkipSpaces ();
const uint64_t start_index = m_index;
const char ch = GetChar();
switch (ch)
{
case '{': return Token::ObjectStart;
case '}': return Token::ObjectEnd;
case '[': return Token::ArrayStart;
case ']': return Token::ArrayEnd;
case ',': return Token::Comma;
case ':': return Token::Colon;
case '\0': return Token::EndOfFile;
case 't':
if (GetChar() == 'r')
if (GetChar() == 'u')
if (GetChar() == 'e')
return Token::True;
break;
case 'f':
if (GetChar() == 'a')
if (GetChar() == 'l')
if (GetChar() == 's')
if (GetChar() == 'e')
return Token::False;
break;
case 'n':
if (GetChar() == 'u')
if (GetChar() == 'l')
if (GetChar() == 'l')
return Token::Null;
break;
case '"':
{
while (1)
{
bool was_escaped = false;
int escaped_ch = GetEscapedChar(was_escaped);
if (escaped_ch == -1)
{
error.Printf("error: an error occurred getting a character from offset %" PRIu64, start_index);
value = std::move(error.GetString());
return Token::Error;
}
else
{
const bool is_end_quote = escaped_ch == '"';
const bool is_null = escaped_ch == 0;
if (was_escaped || (!is_end_quote && !is_null))
{
if (CHAR_MIN <= escaped_ch && escaped_ch <= CHAR_MAX)
{
value.append(1, (char)escaped_ch);
}
else
{
error.Printf("error: wide character support is needed for unicode character 0x%4.4x at offset %" PRIu64, escaped_ch, start_index);
value = std::move(error.GetString());
return Token::Error;
}
}
else if (is_end_quote)
{
return Token::String;
}
else if (is_null)
{
value = "error: missing end quote for string";
return Token::Error;
}
}
}
}
break;
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
{
bool done = false;
bool got_decimal_point = false;
uint64_t exp_index = 0;
bool got_int_digits = (ch >= '0') && (ch <= '9');
bool got_frac_digits = false;
bool got_exp_digits = false;
while (!done)
{
const char next_ch = PeekChar();
switch (next_ch)
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if (exp_index != 0)
{
got_exp_digits = true;
}
else if (got_decimal_point)
{
got_frac_digits = true;
}
else
{
got_int_digits = true;
}
++m_index; // Skip this character
break;
case '.':
if (got_decimal_point)
{
error.Printf("error: extra decimal point found at offset %" PRIu64, start_index);
value = std::move(error.GetString());
return Token::Error;
}
else
{
got_decimal_point = true;
++m_index; // Skip this character
}
break;
case 'e':
case 'E':
if (exp_index != 0)
{
error.Printf("error: extra expenent character found at offset %" PRIu64, start_index);
value = std::move(error.GetString());
return Token::Error;
}
else
{
exp_index = m_index;
++m_index; // Skip this character
}
break;
case '+':
case '-':
// The '+' and '-' can only come after an exponent character...
if (exp_index == m_index - 1)
{
++m_index; // Skip the exponent sign character
}
else
{
error.Printf("error: unexpected %c character at offset %" PRIu64, next_ch, start_index);
value = std::move(error.GetString());
return Token::Error;
}
default:
done = true;
break;
}
}
if (m_index > start_index)
{
value = m_packet.substr(start_index, m_index - start_index);
if (got_decimal_point)
{
if (exp_index != 0)
{
// We have an exponent, make sure we got exponent digits
if (got_exp_digits)
{
return Token::Float;
}
else
{
error.Printf("error: got exponent character but no exponent digits at offset in float value \"%s\"", value.c_str());
value = std::move(error.GetString());
return Token::Error;
}
}
else
{
// No exponent, but we need at least one decimal after the decimal point
if (got_frac_digits)
{
return Token::Float;
}
else
{
error.Printf("error: no digits after decimal point \"%s\"", value.c_str());
value = std::move(error.GetString());
return Token::Error;
}
}
}
else
{
// No decimal point
if (got_int_digits)
{
// We need at least some integer digits to make an integer
return Token::Integer;
}
else
{
error.Printf("error: no digits negate sign \"%s\"", value.c_str());
value = std::move(error.GetString());
return Token::Error;
}
}
}
else
{
error.Printf("error: invalid number found at offset %" PRIu64, start_index);
value = std::move(error.GetString());
return Token::Error;
}
}
break;
default:
break;
}
error.Printf("error: failed to parse token at offset %" PRIu64 " (around character '%c')", start_index, ch);
value = std::move(error.GetString());
return Token::Error;
}
int
JSONParser::GetEscapedChar(bool &was_escaped)
{
was_escaped = false;
const char ch = GetChar();
if (ch == '\\')
{
was_escaped = true;
const char ch2 = GetChar();
switch (ch2)
{
case '"':
case '\\':
case '/':
default:
break;
case 'b': return '\b';
case 'f': return '\f';
case 'n': return '\n';
case 'r': return '\r';
case 't': return '\t';
case 'u':
{
const int hi_byte = DecodeHexU8();
const int lo_byte = DecodeHexU8();
if (hi_byte >=0 && lo_byte >= 0)
return hi_byte << 8 | lo_byte;
return -1;
}
break;
}
return ch2;
}
return ch;
}
JSONValue::SP
JSONParser::ParseJSONObject ()
{
// The "JSONParser::Token::ObjectStart" token should have already been consumed
// by the time this function is called
std::unique_ptr<JSONObject> dict_up(new JSONObject());
std::string value;
std::string key;
while (1)
{
JSONParser::Token token = GetToken(value);
if (token == JSONParser::Token::String)
{
key.swap(value);
token = GetToken(value);
if (token == JSONParser::Token::Colon)
{
JSONValue::SP value_sp = ParseJSONValue();
if (value_sp)
dict_up->SetObject(key, value_sp);
else
break;
}
}
else if (token == JSONParser::Token::ObjectEnd)
{
return JSONValue::SP(dict_up.release());
}
else if (token == JSONParser::Token::Comma)
{
continue;
}
else
{
break;
}
}
return JSONValue::SP();
}
JSONValue::SP
JSONParser::ParseJSONArray ()
{
// The "JSONParser::Token::ObjectStart" token should have already been consumed
// by the time this function is called
std::unique_ptr<JSONArray> array_up(new JSONArray());
std::string value;
std::string key;
while (1)
{
JSONValue::SP value_sp = ParseJSONValue();
if (value_sp)
array_up->AppendObject(value_sp);
else
break;
JSONParser::Token token = GetToken(value);
if (token == JSONParser::Token::Comma)
{
continue;
}
else if (token == JSONParser::Token::ArrayEnd)
{
return JSONValue::SP(array_up.release());
}
else
{
break;
}
}
return JSONValue::SP();
}
JSONValue::SP
JSONParser::ParseJSONValue ()
{
std::string value;
const JSONParser::Token token = GetToken(value);
switch (token)
{
case JSONParser::Token::ObjectStart:
return ParseJSONObject();
case JSONParser::Token::ArrayStart:
return ParseJSONArray();
case JSONParser::Token::Integer:
{
bool success = false;
uint64_t uval = StringConvert::ToUInt64(value.c_str(), 0, 0, &success);
if (success)
return JSONValue::SP(new JSONNumber(uval));
}
break;
case JSONParser::Token::Float:
{
bool success = false;
double val = StringConvert::ToDouble(value.c_str(), 0.0, &success);
if (success)
return JSONValue::SP(new JSONNumber(val));
}
break;
case JSONParser::Token::String:
return JSONValue::SP(new JSONString(value));
case JSONParser::Token::True:
return JSONValue::SP(new JSONTrue());
case JSONParser::Token::False:
return JSONValue::SP(new JSONFalse());
case JSONParser::Token::Null:
return JSONValue::SP(new JSONNull());
default:
break;
}
return JSONValue::SP();
}