[linux] rapidjson Compilation Error for O3DE 22.10

[lgleim]

When trying to compile Cesium O3DE on 22.10 / development, e.g. via https://github.com/CesiumGS/cesium-o3de/pull/45 or https://github.com/CesiumGS/cesium-o3de/pull/50, the compilation will fail with the following error message:

In file included from /root/O3DE/Gems/cesium-o3de/Code/Source/Cesium/Components/TilesetComponent.cpp:34:
In file included from /data/workspace/vendor/packages/CesiumNative/CesiumNative/include/Cesium3DTilesSelection/Tileset.h:19:
/data/workspace/vendor/packages/CesiumNative/CesiumNative/include/rapidjson/fwd.h:116:70: error: typedef redefinition with different types ('GenericValue<[...], MemoryPoolAllocator<>>' vs 'GenericValue<[...], (default) rapidjson_ly::CrtAllocator>')
typedef GenericValue<UTF8<char>, MemoryPoolAllocator<CrtAllocator> > Value;
                                                                     ^
/data/workspace/vendor/packages/CesiumNative/CesiumNative/include/rapidjson/document.h:2485:31: note: previous definition is here
typedef GenericValue<UTF8<> > Value;
                              ^
In file included from /root/O3DE/Gems/cesium-o3de/Code/Source/Cesium/Components/TilesetComponent.cpp:34:
In file included from /data/workspace/vendor/packages/CesiumNative/CesiumNative/include/Cesium3DTilesSelection/Tileset.h:19:
/data/workspace/vendor/packages/CesiumNative/CesiumNative/include/rapidjson/fwd.h:121:86: error: typedef redefinition with different types ('GenericDocument<[...], MemoryPoolAllocator<>, [...]>' vs 'GenericDocument<[...], (default) rapidjson_ly::CrtAllocator, [...]>')
typedef GenericDocument<UTF8<char>, MemoryPoolAllocator<CrtAllocator>, CrtAllocator> Document;
                                                                                     ^
/data/workspace/vendor/packages/CesiumNative/CesiumNative/include/rapidjson/document.h:2889:34: note: previous definition is here
typedef GenericDocument<UTF8<> > Document;
                                 ^
2 errors generated.

As a workaround, one can apply the following patch to the CesiumNative package in the .o3de/3rdparty/packages/CesiumNative/CesiumNative/include/rapidjson folder:

diff --git a/fwd.h b/fwd.h.mod
index 77191c5..8f29100 100644
--- a/fwd.h
+++ b/fwd.h.mod
@@ -113,12 +113,12 @@ struct GenericStringRef;
 template <typename Encoding, typename Allocator> 
 class GenericValue;
 
-typedef GenericValue<UTF8<char>, MemoryPoolAllocator<CrtAllocator> > Value;
+typedef GenericValue<UTF8<> > Value;
 
 template <typename Encoding, typename Allocator, typename StackAllocator>
 class GenericDocument;
 
-typedef GenericDocument<UTF8<char>, MemoryPoolAllocator<CrtAllocator>, CrtAllocator> Document;
+typedef GenericDocument<UTF8<> > Document;
 
 // pointer.h
 
@@ -149,4 +149,3 @@ typedef GenericSchemaValidator<SchemaDocument, BaseReaderHandler<UTF8<char>, voi
 RAPIDJSON_NAMESPACE_END
 
 #endif // RAPIDJSON_RAPIDJSONFWD_H_
-

A proper fix should however either fix the problem in CesiumNative or make the clang compiler accept the typedef redefinition with different types of rapidjson.

[nick-l-o3de]

Sorry about that. In regards to the rapidjson errors, at least.

https://github.com/o3de/o3de/pull/13151

[lgleim]

Since https://github.com/o3de/o3de/pull/13151 is now merged, this issue should now be resolved. Will verify asap.