Files
UnrealEngine/Engine/Source/ThirdParty/Python3/Python3.Build.cs
2025-05-18 13:04:45 +08:00

286 lines
9.9 KiB
C#

// Copyright Epic Games, Inc. All Rights Reserved.
using System;
using System.IO;
using System.Diagnostics;
using System.Collections.Generic;
using UnrealBuildTool;
public class Python3 : ModuleRules
{
public Python3(ReadOnlyTargetRules Target) : base(Target)
{
Type = ModuleType.External;
// if the target doesn't want python support, disable it in C++ via define and do nothing else
// we could check this at a higher level and not even include this module, but the code is already setup to
// disable Python support via this module
if (!Target.bCompilePython)
{
PublicDefinitions.Add("WITH_PYTHON=0");
return;
}
var EngineDir = Path.GetFullPath(Target.RelativeEnginePath);
PythonSDKPaths PythonSDK = null;
if (Target.Platform == UnrealTargetPlatform.Win64 || Target.Platform == UnrealTargetPlatform.Mac || Target.Platform == UnrealTargetPlatform.Linux)
{
// Check if an explicit version of Python was set by the user before using the auto-detection logic. This allow building the engine against
// a user specified Python SDK. WARNING: Ensure to specify a 64-bit version of Python, especially on Windows where the 32-bit version is still available.
var PythonRoot = System.Environment.GetEnvironmentVariable("UE_PYTHON_DIR");
if (PythonRoot != null)
{
PythonSDK = DiscoverPythonSDK(PythonRoot);
if (!PythonSDK.IsValid())
{
PythonSDK = null;
}
}
}
// Perform auto-detection to try and find the Python SDK
if (PythonSDK == null)
{
// Get a list of installed Python SDKs from a set of known installation paths and use the first valid one in the returned list. By default, the first SDK in the returned
// list is the one shipped with the engine. Note: It is preferred to set UE_PYTHON_DIR environment variable to use a custom version of Python.
var PotentialSDKs = GetPotentialPythonSDKs(Target);
foreach (var PotentialSDK in PotentialSDKs)
{
if (PotentialSDK.IsValid())
{
PythonSDK = PotentialSDK;
break;
}
}
}
if (PythonSDK == null)
{
PublicDefinitions.Add("WITH_PYTHON=0");
Console.WriteLine("Python SDK not found");
}
else
{
// If the Python install we're using is within the Engine directory, make the path relative so that it's portable
string EngineRelativePythonRoot = PythonSDK.PythonRoot;
var IsEnginePython = EngineRelativePythonRoot.StartsWith(EngineDir);
if (IsEnginePython)
{
// Strip the Engine directory and then combine the path with the placeholder to ensure the path is delimited correctly
EngineRelativePythonRoot = EngineRelativePythonRoot.Remove(0, EngineDir.Length);
foreach(string FileName in Directory.EnumerateFiles(PythonSDK.PythonRoot, "*", SearchOption.AllDirectories))
{
if(!FileName.EndsWith(".pyc", System.StringComparison.OrdinalIgnoreCase))
{
RuntimeDependencies.Add(FileName);
}
}
EngineRelativePythonRoot = Path.Combine("{ENGINE_DIR}", EngineRelativePythonRoot); // Can't use $(EngineDir) as the placeholder here as UBT is eating it
}
PublicDefinitions.Add("WITH_PYTHON=1");
PublicDefinitions.Add(string.Format("UE_PYTHON_DIR=\"{0}\"", EngineRelativePythonRoot.Replace('\\', '/')));
// Some versions of Python need this define set when building on MSVC
if (Target.Platform == UnrealTargetPlatform.Win64)
{
PublicDefinitions.Add("HAVE_ROUND=1");
}
PublicSystemIncludePaths.AddRange(PythonSDK.PythonIncludePaths);
PublicAdditionalLibraries.AddRange(PythonSDK.PythonLibs);
AppendPythonRuntimeDependencies(Target, IsEnginePython);
}
}
/// <summary>
/// Returns a list of existing PythonSDK by scanning a set of known paths for the specified target. By default, the
/// function puts the Python SDK shipped with the engine first (as the preferred SDK). If a user wants to build against
/// another Python SDK, the list below can be manually modified. The preferred way to override the Python SDK would be
/// to set the UE_PYTHON_DIR environment variable though it might be move convenient for some users to auto-discover
/// from a common install path. Ensure to install, link and use the 64-bit version of Python with Unreal Engine.
/// </summary>
/// <param name="Target"></param>
/// <returns>
/// The list of potential SDKs. The first valid one in the list is going to be used. This is typically the one
/// shipped with the engine.
/// </returns>
private List<PythonSDKPaths> GetPotentialPythonSDKs(ReadOnlyTargetRules Target)
{
var EngineDir = Path.GetFullPath(Target.RelativeEnginePath);
// The Python SDK shipped with the Engine.
var PythonBinaryTPSDir = Path.Combine(EngineDir, "Binaries", "ThirdParty", "Python3");
var PythonSourceTPSDir = Path.Combine(EngineDir, "Source", "ThirdParty", "Python3");
var PotentialSDKs = new List<PythonSDKPaths>();
// todo: This isn't correct for cross-compilation, we need to consider the host platform too
if (Target.Platform == UnrealTargetPlatform.Win64)
{
var PlatformDir = "Win64";
PotentialSDKs.AddRange(
new PythonSDKPaths[] {
new PythonSDKPaths(Path.Combine(PythonBinaryTPSDir, PlatformDir), new List<string>() { Path.Combine(PythonSourceTPSDir, PlatformDir, "include") }, new List<string>() { Path.Combine(PythonSourceTPSDir, PlatformDir, "libs", "python311.lib") }),
// If you uncomment/add a discovery path here, ensure to discover the 64-bit version of Python. As of Python 3.9.7, the 32-bit version still available on Windows (and will crash the engine if used). To avoid editing this file, use UE_PYTHON_DIR environment variable.
//DiscoverPythonSDK("C:/Program Files/Python311"),
//DiscoverPythonSDK("C:/Python311"),
}
);
}
else if (Target.Platform == UnrealTargetPlatform.Mac)
{
PotentialSDKs.AddRange(
new PythonSDKPaths[] {
new PythonSDKPaths(
Path.Combine(PythonBinaryTPSDir, "Mac"),
new List<string>() {
Path.Combine(PythonSourceTPSDir, "Mac", "include")
},
new List<string>() {
Path.Combine(PythonBinaryTPSDir, "Mac", "lib", "libpython3.11.dylib")
}),
}
);
}
else if (Target.IsInPlatformGroup(UnrealPlatformGroup.Unix))
{
if (Target.Architecture == UnrealArch.X64)
{
var PlatformDir = Target.Platform.ToString();
PotentialSDKs.AddRange(
new PythonSDKPaths[] {
new PythonSDKPaths(
Path.Combine(PythonBinaryTPSDir, PlatformDir),
new List<string>() {
Path.Combine(PythonSourceTPSDir, PlatformDir, "include")
},
new List<string>() { Path.Combine(PythonSourceTPSDir, PlatformDir, "lib", "libpython3.11.a") }),
});
PublicSystemLibraries.Add("util"); // part of libc
}
}
return PotentialSDKs;
}
private void AppendPythonRuntimeDependencies(ReadOnlyTargetRules Target, bool IsEnginePython)
{
if (Target.Platform == UnrealTargetPlatform.Linux && IsEnginePython)
{
RuntimeDependencies.Add("$(EngineDir)/Binaries/ThirdParty/Python3/Linux/lib/libpython3.11.so.1.0");
}
// Copy python dll alongside the target in monolithic builds. We statically link a python stub that triggers the dll
// load at global startup, before the paths are configured to find this dll in its native location. By copying it alongside
// the executable we can guarantee it will be found and loaded
if (Target.Platform == UnrealTargetPlatform.Win64 && Target.LinkType == TargetLinkType.Monolithic && IsEnginePython)
{
RuntimeDependencies.Add("$(TargetOutputDir)/python311.dll", "$(EngineDir)/Binaries/ThirdParty/Python3/Win64/python311.dll", StagedFileType.NonUFS);
}
}
private PythonSDKPaths DiscoverPythonSDK(string InPythonRoot)
{
string PythonRoot = InPythonRoot;
List<string> PythonIncludePaths = null;
List<string> PythonLibs = null;
// Work out the include path
if (PythonRoot != null)
{
var PythonIncludePath = Path.Combine(PythonRoot, "include");
if (Target.Platform == UnrealTargetPlatform.Mac)
{
// On Mac the actual headers are inside a "pythonxy" directory, where x and y are the version number
if (Directory.Exists(PythonIncludePath))
{
string[] MatchingIncludePaths = Directory.GetDirectories(PythonIncludePath, "python*");
if (MatchingIncludePaths.Length > 0)
{
PythonIncludePath = Path.Combine(PythonIncludePath, Path.GetFileName(MatchingIncludePaths[0]));
}
}
}
if (Directory.Exists(PythonIncludePath))
{
PythonIncludePaths = new List<string> { PythonIncludePath };
}
else
{
PythonRoot = null;
}
}
// Work out the lib path
if (PythonRoot != null)
{
string LibFolder = null;
string LibNamePattern = null;
if (Target.Platform == UnrealTargetPlatform.Win64)
{
LibFolder = "libs";
LibNamePattern = "python311.lib";
}
else if (Target.Platform == UnrealTargetPlatform.Mac)
{
LibFolder = "lib";
LibNamePattern = "libpython3.11.dylib";
}
else if (Target.Platform == UnrealTargetPlatform.Linux)
{
LibFolder = "lib";
LibNamePattern = "libpython3.11.so";
}
if (LibFolder != null && LibNamePattern != null)
{
var PythonLibPath = Path.Combine(PythonRoot, LibFolder);
if (Directory.Exists(PythonLibPath))
{
string[] MatchingLibFiles = Directory.GetFiles(PythonLibPath, LibNamePattern);
if (MatchingLibFiles.Length > 0)
{
PythonLibs = new List<string>();
foreach (var MatchingLibFile in MatchingLibFiles)
{
PythonLibs.Add(MatchingLibFile);
}
}
}
}
if (PythonLibs == null)
{
PythonRoot = null;
}
}
return new PythonSDKPaths(PythonRoot, PythonIncludePaths, PythonLibs);
}
private class PythonSDKPaths
{
public PythonSDKPaths(string InPythonRoot, List<string> InPythonIncludePaths, List<string> InPythonLibs)
{
PythonRoot = InPythonRoot;
PythonIncludePaths = InPythonIncludePaths;
PythonLibs = InPythonLibs;
}
public bool IsValid()
{
return PythonRoot != null && Directory.Exists(PythonRoot);
}
public string PythonRoot;
public List<string> PythonIncludePaths;
public List<string> PythonLibs;
};
}