Add support for unity builds

modules/vstudio/_preload.lua

@@ -185,6 +185,15 @@
 		}
 	}
 
+	p.api.register {
+		name = "enableUnityBuild",
+		scope = { "config" },
+		kind = "string",
+		allowed = {
+			"On",
+			"Off"
+		}
+	}
 
 --
 -- Decide when the full module should be loaded.

modules/vstudio/vs2010_vcxproj.lua

@@ -196,6 +196,7 @@
 				m.clrSupport,
 				m.characterSet,
 				m.platformToolset,
+				m.enableJumboBuild,
 				m.sanitizers,
 				m.toolsVersion,
 				m.wholeProgramOptimization,
@@ -2550,6 +2551,12 @@
 		end
 	end
 
+	function m.enableJumboBuild(cfg)
+		if _ACTION > "vs2017" and cfg.enableUnityBuild then
+			m.element("EnableUnitySupport", nil, iif(cfg.enableUnityBuild == "On", "true", "false"))
+		end
+	end
+
 	function m.sanitizers(cfg)
 		if _ACTION >= "vs2019" and cfg.sanitize then
 			if table.contains(cfg.sanitize, "Address") then

website/docs/Project-API.md

@@ -72,6 +72,7 @@
 | [editandcontinue](editandcontinue.md)                     |  |
 | [editorintegration](editorintegration.md)                 | Enable or disable IDE integration |
 | [enablewarnings](enablewarnings.md)                       |  |
+| [enableunitybuilds](unitybuilds.md)                       |  |
 | [endian](endian.md)                                       |  |
 | [entrypoint](entrypoint.md)                               | Specify the program entry point function |
 | [exceptionhandling](exceptionhandling.md)                 | Enable or disable exception handling |

website/docs/unitybuilds.md

@@ -0,0 +1,29 @@
+Enables Unity Builds in Visual Studio, also known as Jumbo Builds
+
+```lua
+enableUnityBuilds "value"
+```
+
+If no toolset is specified for a configuration, the system or IDE default will be used.
+
+### Parameters ###
+
+`value` is one of:
+* `On`  - Enables Unity Builds.
+* `Off` - Disables Unity Builds.
+
+### Applies To ###
+
+Project configurations.
+
+### Availability ###
+
+Premake 5.0 and later. Versions are currently only implemented for Visual Studio 2019+.
+
+### Examples ###
+
+Enable Unity Builds.
+
+```lua
+enableUnityBuild "On"
+```