#lockdown Nick.Penwarden
#rb none
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MAJOR FEATURES + CHANGES
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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]
TTP# 331398 - EDITOR: Logspam when opening Visual Studio
Deferring a VS file open request used to use a deferred command to wait until VS had finished opening before opening the requested files, however, this command was essentially simulating a Tick, as if the command was not yet ready to be processed it was simply deferred again, leading to spammed output.
Rather than do this, I've added a Tick function which will attempt to open the entire list of pending files as a single call, rather than try each file individually like the command would.
ReviewedBy Thomas.Sarkanen, Chris.Wood, Max.Preussner
[CL 2058815 by Jamie Dale in Main branch]
#ttp 330039 EDITOR: Platform-agnostic editor code depends on Windows-only VSAccessor headers
#detail Source code access is now extensible via plugins, so any new editors can be easily added.
#add Added SourceCodeAccess module that routes access via plugins.
#change Moved much of the old VSAccessor code into a new VisualStudioSourceCodeAccess plugin.
#add Added a counterpart XCode plugin & migrated the code from FSourceCodeNavigation (Applescript etc.) into there.
#remove Removed applescript for XCode access (it is now done via code).
#remove Removed source code access functionality from platform layer.
#add Added details customization for source code access settings, so users can choose their own accessor.
#remove Removed dependencies on VSAccessor.
#change Changed API in SWidget to not require building a string to be parsed, instead this acesses and forwards filenames & line numbers.
#extra Tested on Mac by Mark S.
reviewed by Andrew.Brown
[CL 2048697 by Thomas Sarkanen in Main branch]
