Read the XML configuration files
Create the C++ dependency cache &generate dependency files
ExternalExecution.cs::WriteUHTManifest
UnrealBuildTool.cs::Main
生成二进制文件
-Target=\"newUBTTest Win64 Development -Project=\\\"D:\\dev\\UBTTest\ewUBTTest\ewUBTTest.uproject\" -WaitMutex -FromMsBuild
BuildMode.cs::Build
UEBuildModuleCPP::Compile
SelectExecutor
ExternalExecution.cs::ExecuteHeaderToolIfNecessary
ParallelExecutor.cs::ExcuteActions
BuildMode.cs::CreateMakeFile
{D:\\dev\\UBTTest\ewUBTTest\ewUBTTest.uproject D:\\dev\\UBTTest\ewUBTTest\\Intermediate\\Build\\Win64\ewUBTTest\\Development\ewUBTTest.uhtmanifest -WarningsAsErrors}
Get DLLBinary、module of plugin、DependencyModules
UhtSession.cs::StepExport
LinkEnvironmentUEToolChain
Parse the command line arguments
CreateBinaryCompileEnvironment
Exporter.Delegate(this)（通过委托UHTMode导出）
ExecuteActions
UEBuildBinary::SetupBinaryLinkEnvironment
FindSharedPCHs
Run and Parse(运行UHT核心步骤)
Run UHT
Unreal Header Tool (UHT) 的核心会话对象，负责管理整个头文件处理和代码生成过程
UnrealHeaderToolMode.cs::Excute
UEBuildTarget.cs::Build
Run the output exporter
UhtCodeGenerator.cs::CodeGenerator
GetCompilerArguments
UEBuildBinary::Build
BuildMode.cs::Execute
Log System
CppConfigurationCppCompileEnvironment
Parse and build the targets
Generate the command line
UhtHeaderCodeGeneratorHFile.cs
Write the command line
ActionGraph.cs::ExecuteActions
Create and build the target
获取编译参数
UhtHeaderCodeGeneratorCppFile.cs
Grab the environment.
GatherDependencyModules
EnvironmentVariables
ModulesToGenerateHeadersFor
GetClArguments
ExecuteHeaderToolIfNecessary
VCCompileAction.cs
GatherOutputItems
makefile.bin
create Session
{D:\\dev\\UBTTest\ewUBTTest\\Intermediate\\Build\\Win64\ewUBTTest\\Development\\Makefile.bin}
VCToolChain.cs::CompileCPPFiles
处理器定义、路径、源文件、目标文件、链接参数
Create a QueuedAction instance for each action in the makefiles
Write() 序列化编译动作（如编译器路径、源文件、输出文件、包含路径、宏定义等）写入一个二进制流）
