error: use of undeclared identifier 'il2cpp_codegen_initialize_method

Unity Engine
1

I have a unity project that I’m using as a library for unity. I upgraded my old project to unity 2020.3 and I’m having a building error like this.

D:\project\unityLibrary\src\main\Il2CppOutputProject\Source\il2cppOutput\Il2CppAttributes.cpp:8870:3: error: use of undeclared identifier 'il2cpp_codegen_initialize_method'
                il2cpp_codegen_initialize_method (PropertyInfo_t_CustomAttributesCacheGenerator_MetadataUsageId);
                ^
D:\project\unityLibrary\src\main\Il2CppOutputProject\Source\il2cppOutput\Il2CppAttributes.cpp:10033:3: error: use of undeclared identifier 'il2cpp_codegen_initialize_method'
                il2cpp_codegen_initialize_method (SemaphoreSlim_t3EF85FC980AE57957BEBB6B78E81DE2E3233D385_CustomAttributesCacheGenerator_SemaphoreSlim_WaitUntilCountOrTimeoutAsync_mDC94D9B33D339D5EB3B148DD1A20AB756D2605A2_MetadataUsageId);
                ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.


Invocation was: Executable: "C:\Users\acer\AppData\Local\Android\Sdk\ndk\20.0.5594570\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++"
Arguments: -DNET_4_0 -DUNITY_AOT -DIL2CPP_MONO_DEBUGGER_DISABLED -DGC_NOT_DLL -DRUNTIME_IL2CPP -DBASELIB_INLINE_NAMESPACE=il2cpp_baselib -DLINUX -DANDROID -DPLATFORM_ANDROID -D__linux__ -D__STDC_FORMAT_MACROS -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\external\bdwgc\include" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\libil2cpp\include" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\libil2cpp" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\libil2cpp" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\external\bdwgc\include" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\external\xxHash" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\external\baselib\Include" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\external\baselib\Platforms\Android\Include" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\IL2CPP\libil2cpp\pch" -I"D:\project\unityLibrary\src\main\Il2CppOutputProject\Source\il2cppOutput" -I"." -c -g -DNDEBUG -fexceptions -fno-limit-debug-info -fdata-sections -ffunction-sections -Wa,--noexecstack -fno-rtti -std=c++11 -fno-strict-aliasing -fvisibility=hidden -fvisibility-inlines-hidden -fno-strict-overflow -fno-addrsig -fPIC -Os -stdlib=libc++ -target armv7-linux-androideabi19 -D__ANDROID_API__=19 -march=armv7-a -mfloat-abi=softfp -mfpu=neon-fp16 -Wno-unused-value "D:\project\unityLibrary\src\main\Il2CppOutputProject\Source\il2cppOutput\Il2CppAttributes.cpp" -o ""D:\project/unityLibrary/build/il2cpp_armeabi-v7a_Release/il2cpp_cache/5FA346F9DCFBD3A2F492408D19AEDB1C.o"

   at Unity.IL2CPP.Building.CppProgramBuilder.BuildAllCppFiles(IEnumerable`1 sourceFilesToCompile, IBuildStatisticsCollector statisticsCollector)
   at Unity.IL2CPP.Building.CppProgramBuilder.Build(IBuildStatistics& statistics)
   at il2cpp.Compilation.CompilationDriver.Run(RuntimePlatform platform, BuildingOptions buildingOptions)
   at il2cpp.Program.DoRun(String[] args, RuntimePlatform platform, BuildingOptions buildingOptions)
   at il2cpp.Program.Run(String[] args, Boolean setInvariantCulture)
   at il2cpp.Program.Main(String[] args)

> Task :unityLibrary:BuildIl2CppTask FAILED

Execution failed for task ':unityLibrary:BuildIl2CppTask'.
> Process 'command '"D:\project/unityLibrary/src/main/Il2CppOutputProject/IL2CPP/build/deploy/net471/il2cpp.exe'' finished with non-zero exit value -532462766

Can anyone help me or guide me through how to solve this?

2

It looks like a header file cannot be found. I’m not sure what it is happening differently here since Unity is built as a library though. Can you use the same installation to build a empty project with Unity? That should validate that the proper header exists in the Unity installation.

3

Thank you for your reply. Yes, I will follow up and check.

4

hi, @JoshPeterson I’ve checked it with an empty project. But there is no Il2cppAttribute.CPP file on unityLibrary\src\main\Il2CppOutputProject\Source\il2cppOutput folder. Seems like it is not created during the exportation.

5

Ahh ok, I think I see what happened here. In 2020.3, IL2CPP no longer generates a Il2CppAttributes.cpp file. In addition, the il2cpp_codegen_initialize_method function no longer exists. Both existed in 2019.4 and earlier.

So it look like there is some stale generated source code here, left over from a previous Unity version. If it is possible to remove that stale code, then this might work.

6

@JoshPeterson Thank you. Let me clear one thing, if there is no Il2CppAttributes.cpp file generate anymore on these versions, how is that possible to call such a method from other classes? Also, I will try your suggestion as well.

7

Which method specifically do you mean?

8

il2cpp_codegen_initialize_method.
I may be mistaken because I’m kinda new to this Android-related stuff.

9

That method no longer exists in Unity 2020.3. However, you should never write code which calls that method. It is an implementation detail of the way that IL2CPP generates C++ code. As long as all of the code generated for a project is generated with the same version of Unity, this error should not occur.

10

Oh, I see. I hope that this stuff is not related to native calls between unity and ios/ android. Anyhow, I’m on process of cleaning the project. I will keep you posted

11

No, this should not be related to native calls at all.