UE4调试UAT时为何断点不了BuildCookRun的部分代码

背景

我之前写了一篇文档，大意是使用 UAT 来调试 BuildCookRun 命令：

UE4如何调试BuildCookRun-CSDN博客

（图1）

但发现某一些cs代码（代码1）无法断点调试，配置如图1所示，图中马赛克的参数如代码2所示。 

//代码1：
private LinkEnvironment SetupBinaryLinkEnvironment(ReadOnlyTargetRules Target, UEToolChain ToolChain, LinkEnvironment LinkEnvironment, CppCompileEnvironment CompileEnvironment, FileReference SingleFileToCompile, ISourceFileWorkingSet WorkingSet, DirectoryReference ExeDir, TargetMakefile Makefile)
{……Log.TraceInformation("Compile target:{0}, module:{1}, LinkType:{2} ", Target.Name,    Module.Name, Target.LinkType);
LinkInputFiles = Module.Compile(Target, ToolChain, BinaryCompileEnvironment, SingleFileToCompile, WorkingSet, Makefile);……}

//代码2：
-ScriptsForProject=j:\Light_Check_MyGame\MyGame_Mini\MyGame_Mini.uproject   BuildCookRun -nop4 -project=j:\Light_Check_MyGame\MyGame_Mini\MyGame_Mini.uproject  -cook -stage -archive -archivedirectory=j:\Light_Check_MyGame\MyGame_Mini\Saved\Archived   -package -ue4exe=j:\Light_Check_MyGame\EngineSource/Engine/Binaries/Win64/UE4Editor-Cmd.exe -compressed -pak -prereqs -nodebuginfo -manifests -targetplatform=Win64 -build -target=MyGame_Mini  -clientconfig=Development -utf8output -compile

原因分析

原来，我的调试需求其实是想要调试“编译代码”的步骤，这只是 BuildCookRun 功能中的一部分，体现在  -build 参数这儿。BuildCookRun 是由 UAT 直接实现的，它调用UBT 去跑一系列动作，包括 Build Cook Archive 等，如代码3所示。

//代码3： EngineSource\Engine\Source\Programs\AutomationTool\Scripts\BuildCookRun.Automation.csprotected void DoBuildCookRun(ProjectParams Params){const ProjectBuildTargets ClientTargets = ProjectBuildTargets.ClientCooked | ProjectBuildTargets.ServerCooked;Project.Build(this, Params, WorkingCL, bGenerateNativeScripts ? (ProjectBuildTargets.All & ~ClientTargets) : ProjectBuildTargets.All);Project.Cook(Params);        Project.CopyBuildToStagingDirectory(Params);Project.Package(Params, WorkingCL);Project.Archive(Params);Project.Deploy(Params);PrintRunTime();Project.Run(Params);Project.GetFile(Params);}

其中，Project.Build() ，我们今天的主角，调用的是另外一个程序 exe （神秘程序X），代码中的 Run 的底层是调用 IProcessResult Result = ProcessManager.CreateProcess  ，即操作系统的进程调用。

// 代码4：J:\\EngineSource\Engine\Source\Programs\AutomationTool\AutomationUtils\UBTUtils.cspublic static void RunUBT(CommandEnvironment Env, string UBTExecutable, string CommandLine){
……IProcessResult Result = Run(UBTExecutable, CommandLine, Options: ERunOptions.AllowSpew | ERunOptions.NoStdOutCapture); // 调用操作系统里的命令行if(Result.ExitCode != 0){throw new AutomationException((ExitCode)Result.ExitCode, "UnrealBuildTool failed. See log for more details. ({0})", CommandUtils.CombinePaths(Env.FinalLogFolder, LogName)) { OutputFormat = AutomationExceptionOutputFormat.Minimal };}}

这个神秘程序 X （代码4中的 UBTExecutable），及其参数（代码4中的 CommandLine），就是：

程序：J:\Light_Check_MyGame\EngineSource\Engine\Binaries\DotNET\UnrealBuildTool.exe

参数：UnrealHeaderTool Win64 Development -Project=j:\Light_Check_MyGame\_MyGame_Mini\_MyGame_Mini.uproject j:\Light_Check_MyGame\_MyGame_Mini\_MyGame_Mini.uproject -NoUBTMakefiles -Manifest=J:\Light_Check_MyGame\EngineSource\Engine\Intermediate\Build\Manifest.xml -NoHotReload -log="J:\Light_Check_MyGame\EngineSource\Engine\Programs\AutomationTool\Saved\Logs\UBT-UnrealHeaderTool-Win64-Development.txt"

由此，我们得知，UAT 调用了 UBT 。所以我们如果要看代码的编译过程，就应该调试UBT，参考这篇文章：  UBT如何编译UE4工程代码_编译ue4工程的文件-CSDN博客。 那么下图6中的所有代码范围，都属于 UBT 的范围，因此都应该按 UBT 来调试。这就是本文标题 《UE4调试UAT时为何断点不了BuildCookRun的部分代码》的答案了。

（图6）

下面贴出堆栈方便作为参考。

BuildCookRun的执行堆栈

BuildCookRun.DoBuildCookRun() at J:/Light_Check_UHD/EngineSource/Engine/Source/Programs/AutomationTool/Scripts/BuildCookRun.Automation.cs:line 198
BuildCookRun.ExecuteBuild() at J:/Light_Check_UHD/EngineSource/Engine/Source/Programs/AutomationTool/Scripts/BuildCookRun.Automation.cs:line 39
BuildCommand.Execute()
Automation.Execute()
Automation.Process()
Program.MainProc()
Program.<>c__DisplayClass1_0.<Main>b__2()
InternalUtils.RunSingleInstance()
Program.Main()
[External code: 2 frames]
Launcher.Main()

RunUBT的执行堆栈

CommandUtils.RunUBT() at EngineSource/Engine/Source/Programs/AutomationTool/AutomationUtils/UBTUtils.cs:line 23
CommandUtils.RunUBT() at EngineSource/Engine/Source/Programs/AutomationTool/AutomationUtils/UBTUtils.cs:line 89
UE4Build.BuildWithUBT()
UE4Build.Build()
Project.Build()
BuildCookRun.DoBuildCookRun()
BuildCookRun.ExecuteBuild()
BuildCommand.Execute()
Automation.Execute()
Automation.Process()
Program.MainProc()
Program.<>c__DisplayClass1_0.<Main>b__2()
InternalUtils.RunSingleInstance()
Program.Main()
[External code: 2 frames]
Launcher.Main()