UE5_Study/docs/Build & Automation System/AutomationToolDriver.md

Automation Tool Driver

For a general overview of the Automation Tool see AutomationTool

A simple C# program to help a user script unattended processes the engine can complete.
The entire tool is implemented within Program.cs and has all its implmentationw within the Program class.
The following headers will be a breakdown of each of its members.

Main

1. Sets up logger
2. Call ParseCommandLine (populates AutomationToolCommandLine and ``CommandsToExecute`)
3. Waits for debugger attachment if AutomationCommandLine detects -WaitForDebugger is set.
4. If MacOS or Linux setup Ctrl+C to be handled correctly so there is no zombie process situation.
5. Set the working directory for the Environment (to the Engine's root directory)
6. Various contextual logging ( operating env, whether launched from launcher, app version...)
7. Run MainProc using ProcessSingleton.RunSingleInstanceAsync

AutomationToolCommandLine

A static data member. Is of type System.ParsedCommandline. and popualated by Main.

Flag	Summary
-Verbose	Enables verbose logging.
-VeryVerbose	Enables very verbose logging.
-TimeStamps	Adds timestamps to log entries (no specific description provided).
-Submit	Allows UAT command to submit changes.
-NoSubmit	Prevents any submit attempts.
-NoP4	Disables Perforce functionality (default if not run on a build machine).
-P4	Enables Perforce functionality (default if run on a build machine).
-IgnoreDependencies	Ignores script dependencies (no specific description provided).
-Help	Displays help information.
-List	Lists all available commands.
-NoKill	Does not kill any spawned processes on exit.
-UTF8Output	Outputs logs in UTF-8 encoding (no specific description provided).
-AllowStdOutLogVerbosity	Allows standard output log verbosity settings (no specific description provided).
-NoAutoSDK	Disables automatic SDK setup (no specific description provided).
-Compile	Force all script modules to be compiled.
-NoCompile	Do not compile any script modules, run with whatever is up to date.
-IgnoreBuildRecords	Ignore build records in determining if script modules are up to date.
-UseLocalBuildStorage	Use local storage for root build storage dir, changing default to Engine\Saved\LocalBuilds.
-WaitForDebugger	Waits for a debugger to be attached, and breaks once debugger successfully attached.
-BuildMachine	Indicates the program is running on a build machine (no specific description provided).
-WaitForUATMutex	Waits for the Unreal Automation Tool mutex (no specific description provided).
-msbuild-verbose	Increases verbosity for MSBuild operations.
-NoCompileUAT	Disables compilation of the Unreal Automation Tool (UAT).

ParseCommandLine

Populates AutomationToolCommandLine and CommandsToExecute (which is within the former and is of type List<CommandInfo>).

It will throw execptions if it finds anything wrong with the commands passed.

ParseProfile

Used by ParseCommandLine. Used if -Profile is passed to the automation tool.
Handles profile files which are used to configure how the AutomationTool executes. These profile files can contain a variety of settings and scripts that need to be processed.

1. Profile File Identification: Identifies if a -profile argument is present in the command line and extracts the profile file path.
2. Arguments Initialization: Initializes a list to store the arguments extracted from the profile file.
3. Iterating Command Line Arguments: Iterates through command line arguments, treating -profile= as the profile file path, and adds other arguments to the Arguments list.
4. Profile File Existence Check: Verifies if the specified profile file actually exists.
5. Reading and Parsing Profile File: Reads the content of the profile file and parses it as JSON to extract a dictionary of settings.
6. Processing Scripts in Profile: Extracts and processes scripts from the scripts section in the JSON:
   • Extracts the name of each script and adds it to the Arguments list if not already present.
   • Removes the 'script' key from the script's dictionary.
   • Calls ParseDictionary on the dictionary to parse and add these settings to the Arguments list.
7. Updating Command Line Arguments: Replaces the original command line arguments with the updated Arguments list containing information processed from the profile file.

ParseParam

Used by ParseCommandLine.

1. Checks for Ignored Parameters: Identifies and skips parameters that are not relevant for processing, ensuring efficiency in parsing.
2. Global Parameter Setting: Sets global parameters that affect the overall operation of the tool, based on the identified command-line arguments.
3. Handling Specific Options: Specifically processes options like -ScriptsForProject, -ScriptDir, and -Telemetry, adjusting the tool's behavior accordingly.
4. Managing Unknown Parameters and Environment Variables: Handles parameters that are unrecognized or not standard, and also manages the influence of environment variables on the tool.
5. Setting Command-line Arguments in AutomationToolCommandLine: Populates the AutomationToolCommandLine with the parsed parameters, which is a key resource used throughout the tool.
6. Exception Handling: Implements error handling to manage potential issues during the parsing process, ensuring stability and user feedback.

ParseDictionary

1. Parameter Verification: Checks if the dictionary parameter is not null, ensuring it's suitable for processing.
2. Dictionary Iteration: Iterates through each key-value pair in the dictionary parameter.
3. Key Processing: Processes the keys of the dictionary, which could involve validation, formatting, or conversion to ensure they are in the correct format for further operations.
4. Value Processing: Examines and processes the values associated with each key. This step may involve additional parsing logic, especially if the values are complex types (like nested dictionaries or lists).
5. Recursive Handling: In cases where values are collections (like lists or dictionaries), ParseDictionary may recursively call itself or other parsing methods (like ParseList) to ensure all elements are properly processed.
6. Constructing Processed Dictionary: Builds a new dictionary with the processed keys and values, which is then ready for use in the tool's operations.

Uses the following helper functions:

ParseString

1. Parameter Verification: Checks if the string parameter is null or empty to ensure only valid strings are processed.
2. Trimming Whitespace: Removes leading or trailing whitespace from the parameter string for uniform processing.
3. String Processing: Applies specific processing to the cleaned string parameter, such as format conversion or additional parsing logic.

ParseList

1. Parameter Verification: Ensures the list parameter is not null for safe processing.
2. List Iteration: Goes through each element in the list parameter.
3. Element Processing: Trims whitespace, validates, and converts each list element to the required format or type.
4. Compiling Processed Elements: Creates a new list or array from the processed elements, prepared for further use in the tool's workflow.

MainProc

Core of the AutomationTool's operation, orchestrating the parsing of command-line arguments and executing the necessary commands.

1. Logger Initialization: Sets up a logger for information logging.
2. Initialization Message: Logs the initialization of script modules.
3. Start Time Recording: Records the start time for performance tracking.
4. Command Line Argument Processing: Retrieves and processes various command-line arguments related to scripts, compilation, and execution modes (e.g., -ScriptsForProject, -ScriptDir, -Compile, -NoCompile, -IgnoreBuildRecords).
5. Command Preparation: Prepares the list of commands to be executed based on the command-line arguments.
6. Script Module Compilation: Initializes and compiles script modules, handling any build processes required and logging related information.
7. Build Success Check: Checks if the script module build was successful. If not, returns an error exit code.
8. Script Module Validation: Ensures that at least one script module (like AutomationUtils) is available after compilation.
9. Loading AutomationUtils Assembly: Loads the AutomationUtils.Automation.dll assembly, essential for further processing.
10. Automation Process Invocation: Invokes the ProcessAsync method from the AutomationTool.Automation class, which drives the execution of the tool's functionality based on the prepared script modules and command-line arguments.
11. Execution Time Logging: Logs the total time taken for script module initialization.
12. Awaiting Process Completion: Awaits the completion of the ProcessAsync method and returns its result as an exit code.

StartupListener

Captures all log output during startup until a log file writer has been created