lldb/tools/debugserver/source/JSON.h

   1 //===---------------------JSON.h --------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLDB_TOOLS_DEBUGSERVER_SOURCE_JSON_H
  10 #define LLDB_TOOLS_DEBUGSERVER_SOURCE_JSON_H
  11
  12 #include "StdStringExtractor.h"
  13
  14 // C includes
  15 #include <cinttypes>
  16 #include <cstdint>
  17
  18 // C++ includes
  19 #include <map>
  20 #include <memory>
  21 #include <ostream>
  22 #include <string>
  23 #include <vector>
  24
  25 class JSONValue {
  26 public:
  27   virtual void Write(std::ostream &s) = 0;
  28
  29   typedef std::shared_ptr<JSONValue> SP;
  30
  31   enum class Kind { String, Number, True, False, Null, Object, Array };
  32
  33   JSONValue(Kind k) : m_kind(k) {}
  34
  35   Kind GetKind() const { return m_kind; }
  36
  37   virtual ~JSONValue() = default;
  38
  39 private:
  40   const Kind m_kind;
  41 };
  42
  43 class JSONString : public JSONValue {
  44 public:
  45   JSONString();
  46   JSONString(const char *s);
  47   JSONString(const std::string &s);
  48
  49   JSONString(const JSONString &s) = delete;
  50   JSONString &operator=(const JSONString &s) = delete;
  51
  52   void Write(std::ostream &s) override;
  53
  54   typedef std::shared_ptr<JSONString> SP;
  55
  56   std::string GetData() { return m_data; }
  57
  58   static bool classof(const JSONValue *V) {
  59     return V->GetKind() == JSONValue::Kind::String;
  60   }
  61
  62   ~JSONString() override = default;
  63
  64 private:
  65   static std::string json_string_quote_metachars(const std::string &);
  66
  67   std::string m_data;
  68 };
  69
  70 class JSONNumber : public JSONValue {
  71 public:
  72   typedef std::shared_ptr<JSONNumber> SP;
  73
  74   // We cretae a constructor for all integer and floating point type with using
  75   // templates and
  76   // SFINAE to avoid having ambiguous overloads because of the implicit type
  77   // promotion. If we
  78   // would have constructors only with int64_t, uint64_t and double types then
  79   // constructing a
  80   // JSONNumber from an int32_t (or any other similar type) would fail to
  81   // compile.
  82
  83   template <typename T, typename std::enable_if<
  84                             std::is_integral<T>::value &&
  85                             std::is_unsigned<T>::value>::type * = nullptr>
  86   explicit JSONNumber(T u)
  87       : JSONValue(JSONValue::Kind::Number), m_data_type(DataType::Unsigned) {
  88     m_data.m_unsigned = u;
  89   }
  90
  91   template <typename T,
  92             typename std::enable_if<std::is_integral<T>::value &&
  93                                     std::is_signed<T>::value>::type * = nullptr>
  94   explicit JSONNumber(T s)
  95       : JSONValue(JSONValue::Kind::Number), m_data_type(DataType::Signed) {
  96     m_data.m_signed = s;
  97   }
  98
  99   template <typename T, typename std::enable_if<
 100                             std::is_floating_point<T>::value>::type * = nullptr>
 101   explicit JSONNumber(T d)
 102       : JSONValue(JSONValue::Kind::Number), m_data_type(DataType::Double) {
 103     m_data.m_double = d;
 104   }
 105
 106   ~JSONNumber() override = default;
 107
 108   JSONNumber(const JSONNumber &s) = delete;
 109   JSONNumber &operator=(const JSONNumber &s) = delete;
 110
 111   void Write(std::ostream &s) override;
 112
 113   uint64_t GetAsUnsigned() const;
 114
 115   int64_t GetAsSigned() const;
 116
 117   double GetAsDouble() const;
 118
 119   static bool classof(const JSONValue *V) {
 120     return V->GetKind() == JSONValue::Kind::Number;
 121   }
 122
 123 private:
 124   enum class DataType : uint8_t { Unsigned, Signed, Double } m_data_type;
 125
 126   union {
 127     uint64_t m_unsigned;
 128     int64_t m_signed;
 129     double m_double;
 130   } m_data;
 131 };
 132
 133 class JSONTrue : public JSONValue {
 134 public:
 135   JSONTrue();
 136
 137   JSONTrue(const JSONTrue &s) = delete;
 138   JSONTrue &operator=(const JSONTrue &s) = delete;
 139
 140   void Write(std::ostream &s) override;
 141
 142   typedef std::shared_ptr<JSONTrue> SP;
 143
 144   static bool classof(const JSONValue *V) {
 145     return V->GetKind() == JSONValue::Kind::True;
 146   }
 147
 148   ~JSONTrue() override = default;
 149 };
 150
 151 class JSONFalse : public JSONValue {
 152 public:
 153   JSONFalse();
 154
 155   JSONFalse(const JSONFalse &s) = delete;
 156   JSONFalse &operator=(const JSONFalse &s) = delete;
 157
 158   void Write(std::ostream &s) override;
 159
 160   typedef std::shared_ptr<JSONFalse> SP;
 161
 162   static bool classof(const JSONValue *V) {
 163     return V->GetKind() == JSONValue::Kind::False;
 164   }
 165
 166   ~JSONFalse() override = default;
 167 };
 168
 169 class JSONNull : public JSONValue {
 170 public:
 171   JSONNull();
 172
 173   JSONNull(const JSONNull &s) = delete;
 174   JSONNull &operator=(const JSONNull &s) = delete;
 175
 176   void Write(std::ostream &s) override;
 177
 178   typedef std::shared_ptr<JSONNull> SP;
 179
 180   static bool classof(const JSONValue *V) {
 181     return V->GetKind() == JSONValue::Kind::Null;
 182   }
 183
 184   ~JSONNull() override = default;
 185 };
 186
 187 class JSONObject : public JSONValue {
 188 public:
 189   JSONObject();
 190
 191   JSONObject(const JSONObject &s) = delete;
 192   JSONObject &operator=(const JSONObject &s) = delete;
 193
 194   void Write(std::ostream &s) override;
 195
 196   typedef std::shared_ptr<JSONObject> SP;
 197
 198   static bool classof(const JSONValue *V) {
 199     return V->GetKind() == JSONValue::Kind::Object;
 200   }
 201
 202   bool SetObject(const std::string &key, JSONValue::SP value);
 203
 204   JSONValue::SP GetObject(const std::string &key) const;
 205
 206   /// Return keyed value as bool
 207   ///
 208   /// \param[in] key
 209   ///     The value of the key to lookup
 210   ///
 211   /// \param[out] value
 212   ///     The value of the key as a bool.  Undefined if the key doesn't
 213   ///     exist or if the key is not either true or false.
 214   ///
 215   /// \return
 216   ///     true if the key existed as was a bool value; false otherwise.
 217   ///     Note the return value is *not* the value of the bool, use
 218   ///     \b value for that.
 219   bool GetObjectAsBool(const std::string &key, bool &value) const;
 220
 221   bool GetObjectAsString(const std::string &key, std::string &value) const;
 222
 223   ~JSONObject() override = default;
 224
 225 private:
 226   typedef std::map<std::string, JSONValue::SP> Map;
 227   typedef Map::iterator Iterator;
 228   Map m_elements;
 229 };
 230
 231 class JSONArray : public JSONValue {
 232 public:
 233   JSONArray();
 234
 235   JSONArray(const JSONArray &s) = delete;
 236   JSONArray &operator=(const JSONArray &s) = delete;
 237
 238   void Write(std::ostream &s) override;
 239
 240   typedef std::shared_ptr<JSONArray> SP;
 241
 242   static bool classof(const JSONValue *V) {
 243     return V->GetKind() == JSONValue::Kind::Array;
 244   }
 245
 246 private:
 247   typedef std::vector<JSONValue::SP> Vector;
 248   typedef Vector::iterator Iterator;
 249   typedef Vector::size_type Index;
 250   typedef Vector::size_type Size;
 251
 252 public:
 253   bool SetObject(Index i, JSONValue::SP value);
 254
 255   bool AppendObject(JSONValue::SP value);
 256
 257   JSONValue::SP GetObject(Index i);
 258
 259   Size GetNumElements();
 260
 261   ~JSONArray() override = default;
 262
 263   Vector m_elements;
 264 };
 265
 266 class JSONParser : public StdStringExtractor {
 267 public:
 268   enum Token {
 269     Invalid,
 270     Status,
 271     ObjectStart,
 272     ObjectEnd,
 273     ArrayStart,
 274     ArrayEnd,
 275     Comma,
 276     Colon,
 277     String,
 278     Integer,
 279     Float,
 280     True,
 281     False,
 282     Null,
 283     EndOfFile
 284   };
 285
 286   JSONParser(const char *cstr);
 287
 288   int GetEscapedChar(bool &was_escaped);
 289
 290   Token GetToken(std::string &value);
 291
 292   JSONValue::SP ParseJSONValue();
 293
 294 protected:
 295   JSONValue::SP ParseJSONValue(const std::string &value, const Token &token);
 296
 297   JSONValue::SP ParseJSONObject();
 298
 299   JSONValue::SP ParseJSONArray();
 300 };
 301
 302 #endif // LLDB_TOOLS_DEBUGSERVER_SOURCE_JSON_H