Run Clang-tidy with modernize-use-auto (#1077)

* Run clang-tidy modify with modernize-use-auto
* Use using instead of typedef

.clang-tidy

@@ -1,5 +1,5 @@
 ---
-Checks:          'google-readability-casting,modernize-use-default-member-init,modernize-use-using,readability-redundant-member-init'
+Checks:          'google-readability-casting,modernize-use-default-member-init,modernize-use-using,modernize-use-auto,readability-redundant-member-init'
 WarningsAsErrors: ''
 HeaderFilterRegex: ''
 AnalyzeTemporaryDtors: false

example/readFromString/readFromString.cpp

@@ -11,7 +11,7 @@
  */
 int main() {
   const std::string rawJson = R"({"Age": 20, "Name": "colin"})";
-  const int rawJsonLength = static_cast<int>(rawJson.length());
+  const auto rawJsonLength = static_cast<int>(rawJson.length());
   constexpr bool shouldUseOldWay = false;
   JSONCPP_STRING err;
   Json::Value root;

include/json/config.h

@@ -119,23 +119,23 @@ extern JSON_API int msvc_pre1900_c99_snprintf(char* outBuf, size_t size,
 #endif // if !defined(JSON_IS_AMALGAMATION)
 
 namespace Json {
-typedef int Int;
+using Int = int;
-typedef unsigned int UInt;
+using UInt = unsigned int;
 #if defined(JSON_NO_INT64)
-typedef int LargestInt;
+using LargestInt = int;
-typedef unsigned int LargestUInt;
+using LargestUInt = unsigned int;
 #undef JSON_HAS_INT64
 #else                 // if defined(JSON_NO_INT64)
 // For Microsoft Visual use specific types as long long is not supported
 #if defined(_MSC_VER) // Microsoft Visual Studio
-typedef __int64 Int64;
+using Int64 = __int64;
-typedef unsigned __int64 UInt64;
+using UInt64 = unsigned __int64;
 #else                 // if defined(_MSC_VER) // Other platforms, use long long
-typedef int64_t Int64;
+using Int64 = int64_t;
-typedef uint64_t UInt64;
+using UInt64 = uint64_t;
 #endif                // if defined(_MSC_VER)
-typedef Int64 LargestInt;
+using LargestInt = Int64;
-typedef UInt64 LargestUInt;
+using LargestUInt = UInt64;
 #define JSON_HAS_INT64
 #endif // if defined(JSON_NO_INT64)
 

include/json/forwards.h

@@ -29,7 +29,7 @@ class CharReaderBuilder;
 class Features;
 
 // value.h
-typedef unsigned int ArrayIndex;
+using ArrayIndex = unsigned int;
 class StaticString;
 class Path;
 class PathArgument;

include/json/reader.h

@@ -36,8 +36,8 @@ namespace Json {
 class JSONCPP_DEPRECATED(
     "Use CharReader and CharReaderBuilder instead.") JSON_API Reader {
 public:
-  typedef char Char;
+  using Char = char;
-  typedef const Char* Location;
+  using Location = const Char*;
 
   /** \brief An error tagged with where in the JSON text it was encountered.
    *
@@ -187,7 +187,7 @@ private:
     Location extra_;
   };
 
-  typedef std::deque<ErrorInfo> Errors;
+  using Errors = std::deque<ErrorInfo>;
 
   bool readToken(Token& token);
   void skipSpaces();
@@ -226,7 +226,7 @@ private:
   static bool containsNewLine(Location begin, Location end);
   static String normalizeEOL(Location begin, Location end);
 
-  typedef std::stack<Value*> Nodes;
+  using Nodes = std::stack<Value*>;
   Nodes nodes_;
   Errors errors_;
   String document_;

include/json/value.h

@@ -176,21 +176,21 @@ class JSON_API Value {
   friend class ValueIteratorBase;
 
 public:
-  typedef std::vector<String> Members;
+  using Members = std::vector<String>;
-  typedef ValueIterator iterator;
+  using iterator = ValueIterator;
-  typedef ValueConstIterator const_iterator;
+  using const_iterator = ValueConstIterator;
-  typedef Json::UInt UInt;
+  using UInt = Json::UInt;
-  typedef Json::Int Int;
+  using Int = Json::Int;
 #if defined(JSON_HAS_INT64)
-  typedef Json::UInt64 UInt64;
+  using UInt64 = Json::UInt64;
-  typedef Json::Int64 Int64;
+  using Int64 = Json::Int64;
 #endif // defined(JSON_HAS_INT64)
-  typedef Json::LargestInt LargestInt;
+  using LargestInt = Json::LargestInt;
-  typedef Json::LargestUInt LargestUInt;
+  using LargestUInt = Json::LargestUInt;
-  typedef Json::ArrayIndex ArrayIndex;
+  using ArrayIndex = Json::ArrayIndex;
 
   // Required for boost integration, e. g. BOOST_TEST
-  typedef std::string value_type;
+  using value_type = std::string;
 
 #if JSON_USE_NULLREF
   // Binary compatibility kludges, do not use.
@@ -710,8 +710,8 @@ public:
   Value& make(Value& root) const;
 
 private:
-  typedef std::vector<const PathArgument*> InArgs;
+  using InArgs = std::vector<const PathArgument*>;
-  typedef std::vector<PathArgument> Args;
+  using Args = std::vector<PathArgument>;
 
   void makePath(const String& path, const InArgs& in);
   void addPathInArg(const String& path, const InArgs& in,
@@ -726,10 +726,10 @@ private:
  */
 class JSON_API ValueIteratorBase {
 public:
-  typedef std::bidirectional_iterator_tag iterator_category;
+  using iterator_category = std::bidirectional_iterator_tag;
-  typedef unsigned int size_t;
+  using size_t = unsigned int;
-  typedef int difference_type;
+  using difference_type = int;
-  typedef ValueIteratorBase SelfType;
+  using SelfType = ValueIteratorBase;
 
   bool operator==(const SelfType& other) const { return isEqual(other); }
 
@@ -802,12 +802,12 @@ class JSON_API ValueConstIterator : public ValueIteratorBase {
   friend class Value;
 
 public:
-  typedef const Value value_type;
+  using value_type = const Value;
   // typedef unsigned int size_t;
   // typedef int difference_type;
-  typedef const Value& reference;
+  using reference = const Value&;
-  typedef const Value* pointer;
+  using pointer = const Value*;
-  typedef ValueConstIterator SelfType;
+  using SelfType = ValueConstIterator;
 
   ValueConstIterator();
   ValueConstIterator(ValueIterator const& other);
@@ -853,12 +853,12 @@ class JSON_API ValueIterator : public ValueIteratorBase {
   friend class Value;
 
 public:
-  typedef Value value_type;
+  using value_type = Value;
-  typedef unsigned int size_t;
+  using size_t = unsigned int;
-  typedef int difference_type;
+  using difference_type = int;
-  typedef Value& reference;
+  using reference = Value&;
-  typedef Value* pointer;
+  using pointer = Value*;
-  typedef ValueIterator SelfType;
+  using SelfType = ValueIterator;
 
   ValueIterator();
   explicit ValueIterator(const ValueConstIterator& other);

include/json/writer.h

@@ -252,7 +252,7 @@ private:
   static bool hasCommentForValue(const Value& value);
   static String normalizeEOL(const String& text);
 
-  typedef std::vector<String> ChildValues;
+  using ChildValues = std::vector<String>;
 
   ChildValues childValues_;
   String document_;
@@ -326,7 +326,7 @@ private:
   static bool hasCommentForValue(const Value& value);
   static String normalizeEOL(const String& text);
 
-  typedef std::vector<String> ChildValues;
+  using ChildValues = std::vector<String>;
 
   ChildValues childValues_;
   OStream* document_;

src/jsontestrunner/main.cpp

@@ -58,7 +58,7 @@ static Json::String readInputTestFile(const char* path) {
     return "";
   fseek(file, 0, SEEK_END);
   long const size = ftell(file);
-  size_t const usize = static_cast<unsigned long>(size);
+  const auto usize = static_cast<size_t>(size);
   fseek(file, 0, SEEK_SET);
   char* buffer = new char[size + 1];
   buffer[size] = 0;

src/lib_json/json_reader.cpp

@@ -54,7 +54,7 @@ namespace Json {
 #if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
 using CharReaderPtr = std::unique_ptr<CharReader>;
 #else
-typedef std::auto_ptr<CharReader> CharReaderPtr;
+using CharReaderPtr = std::auto_ptr<CharReader>;
 #endif
 
 // Implementation of class Features

src/lib_json/json_tool.h

@@ -71,7 +71,7 @@ enum {
 };
 
 // Defines a char buffer for use with uintToString().
-typedef char UIntToStringBuffer[uintToStringBufferSize];
+using UIntToStringBuffer = char[uintToStringBufferSize];
 
 /** Converts an unsigned integer to string.
  * @param value Unsigned integer to convert to string

src/lib_json/json_value.cpp

@@ -117,7 +117,7 @@ static inline char* duplicateStringValue(const char* value, size_t length) {
   if (length >= static_cast<size_t>(Value::maxInt))
     length = Value::maxInt - 1;
 
-  char* newString = static_cast<char*>(malloc(length + 1));
+  auto newString = static_cast<char*>(malloc(length + 1));
   if (newString == nullptr) {
     throwRuntimeError("in Json::Value::duplicateStringValue(): "
                       "Failed to allocate string value buffer");
@@ -137,8 +137,8 @@ static inline char* duplicateAndPrefixStringValue(const char* value,
                                     sizeof(unsigned) - 1U,
                       "in Json::Value::duplicateAndPrefixStringValue(): "
                       "length too big for prefixing");
-  unsigned actualLength = length + static_cast<unsigned>(sizeof(unsigned)) + 1U;
+  size_t actualLength = sizeof(length) + length + 1;
-  char* newString = static_cast<char*>(malloc(actualLength));
+  auto newString = static_cast<char*>(malloc(actualLength));
   if (newString == nullptr) {
     throwRuntimeError("in Json::Value::duplicateAndPrefixStringValue(): "
                       "Failed to allocate string value buffer");
@@ -518,9 +518,10 @@ bool Value::operator<(const Value& other) const {
   }
   case arrayValue:
   case objectValue: {
-    int delta = int(value_.map_->size() - other.value_.map_->size());
+    auto thisSize = value_.map_->size();
-    if (delta)
+    auto otherSize = other.value_.map_->size();
-      return delta < 0;
+    if (thisSize != otherSize)
+      return thisSize < otherSize;
     return (*value_.map_) < (*other.value_.map_);
   }
   default:

src/lib_json/json_writer.cpp

@@ -86,7 +86,7 @@ namespace Json {
 #if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
 using StreamWriterPtr = std::unique_ptr<StreamWriter>;
 #else
-typedef std::auto_ptr<StreamWriter> StreamWriterPtr;
+using StreamWriterPtr = std::auto_ptr<StreamWriter>;
 #endif
 
 String valueToString(LargestInt value) {

src/test_lib_json/fuzz.cpp

@@ -45,7 +45,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
 
   Json::Value root;
-  const char* data_str = reinterpret_cast<const char*>(data);
+  const auto data_str = reinterpret_cast<const char*>(data);
   try {
     reader->parse(data_str, data_str + size, &root, nullptr);
   } catch (Json::Exception const&) {

src/test_lib_json/jsontest.h

@@ -42,7 +42,7 @@ public:
 /// Must be a POD to allow inline initialisation without stepping
 /// into the debugger.
 struct PredicateContext {
-  typedef unsigned int Id;
+  using Id = unsigned int;
   Id id_;
   const char* file_;
   unsigned int line_;
@@ -102,7 +102,7 @@ private:
   static Json::String indentText(const Json::String& text,
                                  const Json::String& indent);
 
-  typedef std::deque<Failure> Failures;
+  using Failures = std::deque<Failure>;
   Failures failures_;
   Json::String name_;
   PredicateContext rootPredicateNode_;
@@ -129,7 +129,7 @@ private:
 };
 
 /// Function pointer type for TestCase factory
-typedef TestCase* (*TestCaseFactory)();
+using TestCaseFactory = TestCase* (*)();
 
 class Runner {
 public:
@@ -168,7 +168,7 @@ private:
   static void preventDialogOnCrash();
 
 private:
-  typedef std::deque<TestCaseFactory> Factories;
+  using Factories = std::deque<TestCaseFactory>;
   Factories tests_;
 };