Add RAPIDJSON_DIAG_* macros to handle compiler warnings

Warning push/pop support has been added to GCC in version 4.6.0,
and pragmas to ignore certain warnings are present since 4.2.0.
This patch hides the compiler-specific warning push/pop/disable
pragmas behind a macro-based implementation (currently for MSVC and
clang /GCC.

This avoids warnings, as seen e.g. on GCC 4.4:
  ../../include/rapidjson/document.h:14: error: expected [error|warning|ignored] after ‘#pragma GCC diagnostic’
and earlier versions complaining about unknown pragmas being ignored.

Note: unittest.h and perftest.h need to check for compilers
explicitly, as rapidjson.h is not included there.

include/rapidjson/document.h

@@ -6,13 +6,11 @@
 #include <new>		// placement new
 
 #ifdef _MSC_VER
-#pragma warning(push)
-#pragma warning(disable : 4127) // conditional expression is constant
-#endif
-
-#ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Weffc++"
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(4127) // conditional expression is constant
+#elif defined(__GNUC__)
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(effc++)
 #endif
 
 #ifndef RAPIDJSON_NOMEMBERITERATORCLASS
@@ -1168,12 +1166,8 @@ GenericValue<Encoding,Allocator>::GenericValue(const GenericValue<Encoding,Sourc
 
 } // namespace rapidjson
 
-#ifdef _MSC_VER
-#pragma warning(pop)
-#endif
-
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
+#if defined(_MSC_VER) || defined(__GNUC__)
+RAPIDJSON_DIAG_POP
 #endif
 
 #endif // RAPIDJSON_DOCUMENT_H_

include/rapidjson/encodedstream.h

@@ -4,8 +4,8 @@
 #include "rapidjson.h"
 
 #ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Weffc++"
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(effc++)
 #endif
 
 namespace rapidjson {
@@ -264,7 +264,7 @@ private:
 } // namespace rapidjson
 
 #ifdef __GNUC__
-#pragma GCC diagnostic pop
+RAPIDJSON_DIAG_POP
 #endif
 
 #endif // RAPIDJSON_FILESTREAM_H_

include/rapidjson/encodings.h

@@ -4,8 +4,8 @@
 #include "rapidjson.h"
 
 #ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Weffc++"
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(effc++)
 #endif
 
 namespace rapidjson {
@@ -530,7 +530,7 @@ struct Transcoder<Encoding, Encoding> {
 } // namespace rapidjson
 
 #ifdef __GNUC__
-#pragma GCC diagnostic pop
+RAPIDJSON_DIAG_POP
 #endif
 
 #endif // RAPIDJSON_ENCODINGS_H_

include/rapidjson/prettywriter.h

@@ -4,8 +4,8 @@
 #include "writer.h"
 
 #ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Weffc++"
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(effc++)
 #endif
 
 namespace rapidjson {
@@ -184,7 +184,7 @@ private:
 } // namespace rapidjson
 
 #ifdef __GNUC__
-#pragma GCC diagnostic pop
+RAPIDJSON_DIAG_POP
 #endif
 
 #endif // RAPIDJSON_RAPIDJSON_H_

include/rapidjson/rapidjson.h

@@ -156,9 +156,56 @@ template<int x> struct StaticAssertTest {};
 // Helpers
 
 //!@cond RAPIDJSON_HIDDEN_FROM_DOXYGEN
+
 #define RAPIDJSON_MULTILINEMACRO_BEGIN do {  
 #define RAPIDJSON_MULTILINEMACRO_END \
 } while((void)0, 0)
+
+// adopted from Boost
+#define RAPIDJSON_VERSION_CODE(x,y,z) \
+  (((x)*100000) + ((y)*100) + (z))
+
+// token stringification
+#define RAPIDJSON_STRINGIFY(x) RAPIDJSON_DO_STRINGIFY(x)
+#define RAPIDJSON_DO_STRINGIFY(x) #x
+
+///////////////////////////////////////////////////////////////////////////////
+// RAPIDJSON_DIAG_PUSH/POP, RAPIDJSON_DIAG_OFF
+
+#if defined(__clang__) || (defined(__GNUC__) && RAPIDJSON_VERSION_CODE(__GNUC__,__GNUC_MINOR__,__GNUC_PATCHLEVEL__) >= RAPIDJSON_VERSION_CODE(4,2,0))
+
+#define RAPIDJSON_PRAGMA(x) _Pragma(RAPIDJSON_STRINGIFY(x))
+#define RAPIDJSON_DIAG_PRAGMA(x) RAPIDJSON_PRAGMA(GCC diagnostic x)
+#define RAPIDJSON_DIAG_OFF(x) \
+	RAPIDJSON_DIAG_PRAGMA(ignored RAPIDJSON_STRINGIFY(RAPIDJSON_JOIN(-W,x)))
+
+// push/pop support in Clang and GCC>=4.6
+#if defined(__clang__) || (defined(__GNUC__) && RAPIDJSON_VERSION_CODE(__GNUC__,__GNUC_MINOR__,__GNUC_PATCHLEVEL__) >= RAPIDJSON_VERSION_CODE(4,6,0))
+#define RAPIDJSON_DIAG_PUSH RAPIDJSON_DIAG_PRAGMA(push)
+#define RAPIDJSON_DIAG_POP  RAPIDJSON_DIAG_PRAGMA(pop)
+#else // GCC >= 4.2, < 4.6
+#define RAPIDJSON_DIAG_PUSH /* ignored */
+#define RAPIDJSON_DIAG_POP /* ignored */
+#endif
+
+#elif defined(_MSC_VER)
+
+// pragma (MSVC specific)
+#define RAPIDJSON_PRAGMA(x) __pragma(x)
+#define RAPIDJSON_DIAG_PRAGMA(x) RAPIDJSON_PRAGMA(warning(x))
+
+#define RAPIDJSON_DIAG_OFF(x) RAPIDJSON_DIAG_PRAGMA(disable: x)
+#define RAPIDJSON_DIAG_PUSH RAPIDJSON_DIAG_PRAGMA(push)
+#define RAPIDJSON_DIAG_POP  RAPIDJSON_DIAG_PRAGMA(pop)
+
+#else
+
+#define RAPIDJSON_DIAG_OFF(x) /* ignored */
+#define RAPIDJSON_DIAG_PUSH   /* ignored */
+#define RAPIDJSON_DIAG_POP    /* ignored */
+
+#endif // RAPIDJSON_DIAG_*
+
 //!@endcond
 
 ///////////////////////////////////////////////////////////////////////////////

test/perftest/perftest.h

@@ -29,14 +29,16 @@
 #  define __STDC_CONSTANT_MACROS 1 // required by C++ standard
 #endif
 
-#ifdef __GNUC__
-#pragma GCC diagnostic push
+#if defined(__clang__) || defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 2))
 #pragma GCC diagnostic ignored "-Weffc++"
+#if defined(__clang__) || (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
+#pragma GCC diagnostic push
+#endif
 #endif
 
 #include "gtest/gtest.h"
 
-#ifdef __GNUC__
+#if defined(__clang__) || defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
 #pragma GCC diagnostic pop
 #endif
 

test/perftest/rapidjsontest.cpp

@@ -172,8 +172,8 @@ TEST_F(RapidJson, DocumentTraverse) {
 }
 
 #ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Weffc++"
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(effc++)
 #endif
 
 struct ValueCounter : public BaseReaderHandler<> {
@@ -186,7 +186,7 @@ struct ValueCounter : public BaseReaderHandler<> {
 };
 
 #ifdef __GNUC__
-#pragma GCC diagnostic pop
+RAPIDJSON_DIAG_POP
 #endif
 
 TEST_F(RapidJson, DocumentAccept) {

test/unittest/readertest.cpp

@@ -6,8 +6,8 @@
 using namespace rapidjson;
 
 #ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Weffc++"
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(effc++)
 #endif
 
 template<bool expect>
@@ -707,5 +707,5 @@ TEST(Reader, Parse_IStreamWrapper_StringStream) {
 }
 
 #ifdef __GNUC__
-#pragma GCC diagnostic pop
+RAPIDJSON_DIAG_POP
 #endif

test/unittest/unittest.h

@@ -13,14 +13,16 @@
 #pragma warning(disable : 4996) // 'function': was declared deprecated
 #endif
 
-#ifdef __GNUC__
-#pragma GCC diagnostic push
+#if defined(__clang__) || defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 2))
 #pragma GCC diagnostic ignored "-Weffc++"
+#if defined(__clang__) || (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
+#pragma GCC diagnostic push
+#endif
 #endif
 
 #include "gtest/gtest.h"
 
-#ifdef __GNUC__
+#if defined(__clang__) || defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
 #pragma GCC diagnostic pop
 #endif