#lockdown Nick.Penwarden
#rb none
==========================
MAJOR FEATURES + CHANGES
==========================
Change 3209340 on 2016/11/23 by Ben.Marsh
Convert UE4 codebase to an "include what you use" model - where every header just includes the dependencies it needs, rather than every source file including large monolithic headers like Engine.h and UnrealEd.h.
Measured full rebuild times around 2x faster using XGE on Windows, and improvements of 25% or more for incremental builds and full rebuilds on most other platforms.
* Every header now includes everything it needs to compile.
* There's a CoreMinimal.h header that gets you a set of ubiquitous types from Core (eg. FString, FName, TArray, FVector, etc...). Most headers now include this first.
* There's a CoreTypes.h header that sets up primitive UE4 types and build macros (int32, PLATFORM_WIN64, etc...). All headers in Core include this first, as does CoreMinimal.h.
* Every .cpp file includes its matching .h file first.
* This helps validate that each header is including everything it needs to compile.
* No engine code includes a monolithic header such as Engine.h or UnrealEd.h any more.
* You will get a warning if you try to include one of these from the engine. They still exist for compatibility with game projects and do not produce warnings when included there.
* There have only been minor changes to our internal games down to accommodate these changes. The intent is for this to be as seamless as possible.
* No engine code explicitly includes a precompiled header any more.
* We still use PCHs, but they're force-included on the compiler command line by UnrealBuildTool instead. This lets us tune what they contain without breaking any existing include dependencies.
* PCHs are generated by a tool to get a statistical amount of coverage for the source files using it, and I've seeded the new shared PCHs to contain any header included by > 15% of source files.
Tool used to generate this transform is at Engine\Source\Programs\IncludeTool.
[CL 3209342 by Ben Marsh in Main branch]
==========================
MAJOR FEATURES + CHANGES
==========================
Change 2963214 on 2016/05/02 by Ben.Marsh
BuildGraph: Allow specifying optional dependencies for a node, indicating that the build products from an upstream node are desired, but should not block the node from running.
Change 2972295 on 2016/05/10 by Ben.Marsh
EC: Remove spacing in notification emails to reduce size, and help prevent gmail from truncating messages. Also allow mailing notification emails when doing a dry run, and reading stream settings from another branch.
Change 2976096 on 2016/05/12 by Ben.Marsh
EC: Store properties for the last succeeded builds, including the list of users that were notified about it.
Change 2976390 on 2016/05/12 by Ben.Marsh
EC: Add a separate line to the notification email summary with a link to edit settings, and pass the missing ec-update parameter to set the last build status.
Change 2976441 on 2016/05/12 by Ben.Marsh
UAT: Remove log file copy on builders after UAT failure. This is done outside the EC step that originally did it now.
Change 2976456 on 2016/05/12 by Ben.Marsh
BuildGraph: Catch exceptions thrown by child processes failing when building or running UAT commands, and return failure normally without dumping callstacks.
Change 2978440 on 2016/05/16 by Ben.Marsh
EC: Age out entries from the "latest builds" list after a week. There's no obvious way to tell if a node has been removed, but a periodic cleanup should keep the build notifications list in check.
Change 2979446 on 2016/05/16 by Ben.Marsh
Rename ambiguous headers which exist with the same name in different paths.
Change 2979839 on 2016/05/16 by Ben.Marsh
UE4: Renaming HTML5 SocketSubsystem files to eliminate ambiguities.
Change 2979852 on 2016/05/16 by Ben.Marsh
UE4: Use explicit relative paths for public headers in PortalServiceInterfaces modules which do not have unique names
Change 2980113 on 2016/05/17 by Ben.Marsh
UE4: Fix include paths for HTML5 SocketSubsystem files.
Change 2980117 on 2016/05/17 by Ben.Marsh
UE4: Remove reference to private PCH from Oculus common code.
Change 2980186 on 2016/05/17 by Ben.Marsh
UAT: Add a -StopOnErrors parameter to UE4Build, which is propagated to XGE.
Change 2980879 on 2016/05/17 by Ben.Marsh
UE4: Fixup Lightmass to use LightmassPCH.h rather than stdafx.h
Change 2981117 on 2016/05/17 by Ben.Marsh
Portal: Use a unique name for the Portal PCH, rather than just calling it PrivatePCH.h
Change 2981839 on 2016/05/18 by Ben.Marsh
Replace ambiguous D3D11/D3D12 includes with direct includes for the current platform.
#lockdown Nick.Penwarden
[CL 2982178 by Ben Marsh in Main branch]
Please note that file comments had no purpose in nearly all cases and just added visual clutter. The two files that had meaningful file comments had their comments moved into the corresponding classes. There are still hundreds of file comments left in other files that will be removed over time.
Also cleaned up some random stuff along the way:
- relative paths to public headers within the same module are no longer necessary (automatically discovered by UBT now)
- header guards are deprecated, use #pragma once instead (all compilers support it now)
- space between multiple template brackets is no longer required (all compilers support >> now)
- NULL to nullptr, OVERRIDE to override
- spelling errors, whitespace, line breaks
[CL 2104067 by Max Preussner in Main branch]
