Fix gcc warnings (#5071)

common/CMakeLists.txt

@@ -6,6 +6,7 @@ set(common_sources
     bodytypes.cpp
     classes.cpp
     cli/eqemu_command_handler.cpp
+    compiler_macros.h
     compression.cpp
     content/world_content_service.cpp
     crash.cpp

common/compiler_macros.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#if defined(_MSC_VER)
+    #define PUSH_DISABLE_DEPRECATED_WARNINGS() __pragma(warning(push)) \
+                                               __pragma(warning(disable:4996))
+    #define POP_DISABLE_DEPRECATED_WARNINGS()  __pragma(warning(pop))
+#elif defined(__GNUC__) || defined(__clang__)
+    #define PUSH_DISABLE_DEPRECATED_WARNINGS() _Pragma("GCC diagnostic push") \
+                                               _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
+    #define POP_DISABLE_DEPRECATED_WARNINGS()  _Pragma("GCC diagnostic pop")
+#else
+    #define PUSH_DISABLE_DEPRECATED_WARNINGS()
+    #define POP_DISABLE_DEPRECATED_WARNINGS()
+#endif
+
+#if defined(_MSC_VER) && !defined(__clang__)
+    #define UNREACHABLE() __assume(0)
+#else
+    #define UNREACHABLE() __builtin_unreachable()
+#endif

common/json/jsoncpp.cpp

@@ -271,11 +271,7 @@ static size_t const stackLimit_g = JSONCPP_DEPRECATED_STACK_LIMIT; // see readVa
 
 namespace Json {
 
-#if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
 typedef std::unique_ptr<CharReader> CharReaderPtr;
-#else
-typedef std::auto_ptr<CharReader>   CharReaderPtr;
-#endif
 
 // Implementation of class Features
 // ////////////////////////////////
@@ -4153,11 +4149,7 @@ Value& Path::make(Value& root) const {
 
 namespace Json {
 
-#if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
 typedef std::unique_ptr<StreamWriter> StreamWriterPtr;
-#else
-typedef std::auto_ptr<StreamWriter>   StreamWriterPtr;
-#endif
 
 static bool containsControlCharacter(const char* str) {
   while (*str) {