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

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

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;
-  char* newString = static_cast<char*>(malloc(actualLength));
+  size_t actualLength = sizeof(length) + length + 1;
+  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());
-    if (delta)
-      return delta < 0;
+    auto thisSize = value_.map_->size();
+    auto otherSize = other.value_.map_->size();
+    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_;
 };