ue4_26-defines-fix.patch

ue4_26-defines-fix.patch

diff --git a/Engine/Source/Programs/UnrealBuildTool/Configuration/UEBuildModuleCPP.cs b/Engine/Source/Programs/UnrealBuildTool/Configuration/UEBuildModuleCPP.cs
index ad61e4bdf57..9971b8ca9fa 100644
--- a/Engine/Source/Programs/UnrealBuildTool/Configuration/UEBuildModuleCPP.cs
+++ b/Engine/Source/Programs/UnrealBuildTool/Configuration/UEBuildModuleCPP.cs
@@ -437,6 +437,11 @@ namespace UnrealBuildTool
                        // Write all the definitions to a separate file
                        CreateHeaderForDefinitions(CompileEnvironment, IntermediateDirectory, null, Graph);
 
+                       // patch 
+                       if (CompileEnvironment.Definitions.Count > 0)
+                       {
+                               CompileEnvironment.Definitions.Clear();
+                       }
+
                        // Mapping of source file to unity file. We output this to intermediate directories for other tools (eg. live coding) to use.
                        Dictionary<FileItem, FileItem> SourceFileToUnityFile = new Dictionary<FileItem, FileItem>();
 
@@ -923,6 +928,11 @@ namespace UnrealBuildTool
                        // Write all the definitions out to a separate file
                        CreateHeaderForDefinitions(CompileEnvironment, IntermediateDirectory, "Adaptive", Graph);
 
+                        // patch
+                        if (CompileEnvironment.Definitions.Count > 0)
+                        {
+                                CompileEnvironment.Definitions.Clear();
+                        }
+
                        // Compile the files
                        return ToolChain.CompileCPPFiles(CompileEnvironment, Files, IntermediateDirectory, ModuleName, Graph);
                }
@@ -935,6 +945,11 @@ namespace UnrealBuildTool
                        // Write all the definitions out to a separate file
                        CreateHeaderForDefinitions(CompileEnvironment, IntermediateDirectory, "Adaptive", Graph);
 
+                        // patch
+                        if (CompileEnvironment.Definitions.Count > 0){
+                                CompileEnvironment.Definitions.Clear();
+                        }
+
                        // Compile the files
                        return ToolChain.CompileCPPFiles(CompileEnvironment, Files, IntermediateDirectory, ModuleName, Graph);
                }
@@ -1005,7 +1020,7 @@ namespace UnrealBuildTool
                                        PrecompiledHeaderInstance Instance = CreatePrivatePCH(ToolChain, FileItem.GetItemByFileReference(FileReference.Combine(ModuleDirectory, Rules.PrivatePCHHeaderFile)), CompileEnvironment, Graph);
 
                                        CompileEnvironment = new CppCompileEnvironment(CompileEnvironment);
-                                       CompileEnvironment.Definitions.Clear();
+                                       // CompileEnvironment.Definitions.Clear(); // @TODO: Do not clear definitions prior to end of their usefulness
                                        CompileEnvironment.PrecompiledHeaderAction = PrecompiledHeaderAction.Include;
                                        CompileEnvironment.PrecompiledHeaderIncludeFilename = Instance.HeaderFile.Location;
                                        CompileEnvironment.PrecompiledHeaderFile = Instance.Output.PrecompiledHeaderFile;
@@ -1049,7 +1064,7 @@ namespace UnrealBuildTool
                                                }
 
                                                CompileEnvironment = new CppCompileEnvironment(CompileEnvironment);
-                                               CompileEnvironment.Definitions.Clear();
+                                               // CompileEnvironment.Definitions.Clear(); //  @todo: Do not clear definitions prior to end of their usefulness
                                                CompileEnvironment.ForceIncludeFiles.Add(PrivateDefinitionsFileItem);
                                                CompileEnvironment.PrecompiledHeaderAction = PrecompiledHeaderAction.Include;
                                                CompileEnvironment.PrecompiledHeaderIncludeFilename = Instance.HeaderFile.Location;