一次Unity3D IL2CPP 打包错误

目录

一、错误描述

二、问题分析

三、解决方法

四、效果验证

五、后记

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一、错误描述

采用IL2CPP生成的时候，出现了4个错误：

（1）Building Library\Bee\artifacts\WinPlayerBuildProgram\ei6vj\ku08_i_vm6.lump.obj failed with output:

（2）BuildFailedException: Incremental Player build failed!

（3）Build completed with a result of ‘Failed’ in 19 seconds (18657 ms)

（4）UnityEditor.BuildPlayerWindow+BuildMethodException: 3 errors

之前能成功生成的程序，就这样报错了。

二、问题分析

这个程序明明几个月前才编译过，为啥突然不行了，也在网上做了搜索，所得到的回答均不尽如人意，仔细思考，这种情况会不会跟本机环境有关？而容易出问题的地方更多是在IL转换成C++代码，然后编译生成的过程里，回到前述4个错误，后面3个，更多是描述问题的结果，第1个是问题关键，提示了在编译生成中间文件时出错了。

查看第一个错误：
Building Library\Bee\artifacts\WinPlayerBuildProgram\ei6vj\ku08_i_vm6.lump.obj failed with output:

可看到以下细节（该obj文件名可以是*_vm6.lump.obj，因中间文件名字可能变化）：

1. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(71): error C2039: 'hash_compare': is not a member of 'stdext'
2. C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.34.31933\include\iterator(1426): note: see declaration of 'stdext'
3. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(71): error C2065: 'hash_compare': undeclared identifier
4. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(71): error C2275: 'Key': expected an expression instead of a type
5. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(38): error C2976: 'Il2CppReaderWriterLockedHashMap': too few template arguments
6. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
7. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(38): error C2974: 'Il2CppReaderWriterLockedHashMap': invalid template argument for 'HashFcn', type expected
8. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
9. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(38): error C2955: 'Il2CppReaderWriterLockedHashMap': use of class template requires template argument list
10. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
11. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(47): error C2955: 'Il2CppReaderWriterLockedHashMap': use of class template requires template argument list
12. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
13. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(385): error C2662: 'bool Il2CppReaderWriterLockedHashMap::TryGet(const Il2CppHashMap::key_type &,T *)': cannot convert 'this' pointer from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap &'
14. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(385): note: Reason: cannot convert from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap'
15. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(385): note: Conversion requires a second user-defined-conversion operator or constructor
16. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(90): note: see declaration of 'Il2CppReaderWriterLockedHashMap::TryGet'
17. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(385): note: while trying to match the argument list '(Il2CppClass *, Il2CppClass **)'
18. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(438): error C2662: 'bool Il2CppReaderWriterLockedHashMap::Add(const Il2CppHashMap::key_type &,const T &)': cannot convert 'this' pointer from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap &'
19. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(438): note: Reason: cannot convert from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap'
20. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(438): note: Conversion requires a second user-defined-conversion operator or constructor
21. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(102): note: see declaration of 'Il2CppReaderWriterLockedHashMap::Add'
22. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(438): note: while trying to match the argument list '(Il2CppClass *, Il2CppClass *)'
23. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): error C2955: 'Il2CppReaderWriterLockedHashMap': use of class template requires template argument list
24. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
25. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): error C2662: 'Il2CppHashMap::iterator Il2CppReaderWriterLockedHashMap::UnlockedBegin(void)': cannot convert 'this' pointer from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap &'
26. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): note: Reason: cannot convert from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap'
27. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): note: Conversion requires a second user-defined-conversion operator or constructor
28. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(121): note: see declaration of 'Il2CppReaderWriterLockedHashMap::UnlockedBegin'
29. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): note: while trying to match the argument list '()'
30. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): error C2662: 'Il2CppHashMap::iterator Il2CppReaderWriterLockedHashMap::UnlockedEnd(void)': cannot convert 'this' pointer from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap &'
31. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): note: Reason: cannot convert from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap'
32. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): note: Conversion requires a second user-defined-conversion operator or constructor
33. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(127): note: see declaration of 'Il2CppReaderWriterLockedHashMap::UnlockedEnd'
34. C:\Program Files\Unity\Hub\Editor\2022.1.22f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1157): note: while trying to match the argument list '()'
35. UnityEditor.BuildPlayerWindow:BuildPlayerAndRun ()

排除网上所说的UnityEditor导致的可能后，焦点就落在了STL上了，具体来说就是unordered_map替代hash_map这个问题。hash_map是一个非标准的STL容器，一般来说是要用unordered_map去替代它，但是IL2CPP是机器生成C++代码，修改自动生成代码不太现实，故得从错误忽略着手，如我们常用的宏定义：

#define _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS

因此，对于Unity3D，我们可以通过添加错误忽略的方法处理。

三、解决方法

（1）环境变量方法（修改_CL_值）：

添加环境变量_CL_，变量值为/D_SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS。在MSVC编译生成的时候加入“/D_SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS”对

（2）临时改变CL编译选项：

在Unity3D项目中添加C#脚本（可任意位置添加），在预处理生成时，添加C++编译选项
“/D_SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS”。

1. #if UNITY_EDITOR
   using System;
   using UnityEditor.Build;
   using UnityEditor.Build.Reporting;
   public class MsvcStdextWorkaround : IPreprocessBuildWithReport
   {
       const string kWorkaroundFlag = "/D_SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS";
       public int callbackOrder => 0;
       public void OnPreprocessBuild(BuildReport report)
       {
           var clEnv = Environment.GetEnvironmentVariable("_CL_");
           if (string.IsNullOrEmpty(clEnv))
           {
               Environment.SetEnvironmentVariable("_CL_", kWorkaroundFlag);
           }
           else if (!clEnv.Contains(kWorkaroundFlag))
           {
               clEnv += " " + kWorkaroundFlag;
               Environment.SetEnvironmentVariable("_CL_", clEnv);
           }
       }
   }
   #endif // UNITY_EDITOR

四、效果验证

忽略掉hash_map/unorder_map错误后，正确生成程序：

五、后记

在解决这个问题的时候，尝试了非百度的搜索引擎搜索前文中第一个错误，能在Unity3D官网寻找到解决办法。Unity3D官方论坛上说这是微软MSVC编译器（或者说Visual Studio）的一个BUG，但仔细思考，我反而认为问题还是在于应用标准STL容器unordered_map替代hash_map的问题，该问题的产生应该还是出在IL2CPP将Unity3D脚本生成的MSIL汇编转换为C++的过程中，对C#容器采用hash_map来“翻译”而导致。

参考链接：

（1）BUG: Unity 2022.1.22f1 with IL2CPP not working：https://forum.unity.com/threads/unity-2022-1-22f1-with-il2cpp-not-working.1359580/

（2）BUG: IL2CPP error on Building for Windows: https://forum.unity.com/threads/il2cpp-error-on-building-for-windows.1351589/