From 326b95c6388b5d9b990548398d0b6d52c0a0839a Mon Sep 17 00:00:00 2001
From: Jamie Reece Wilson <me@reece.sx>
Date: Wed, 23 Aug 2023 21:55:40 +0100
Subject: [PATCH] [+] LTO

---
 Core/JSON/jsonProjectHandlers.lua | 45 +++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/Core/JSON/jsonProjectHandlers.lua b/Core/JSON/jsonProjectHandlers.lua
index 535aa20..19b1cf0 100644
--- a/Core/JSON/jsonProjectHandlers.lua
+++ b/Core/JSON/jsonProjectHandlers.lua
@@ -456,6 +456,41 @@ local kAllProjectHeaders =
     "linkDepends", "includeDepends"
 }
 
+local function auBlockProjectKeyLtoNotMsvc(processor, value)
+    if (value) then
+        auFilter{"toolset:clang", "not system:windows"}
+            --buildoptions "-flto=thin"
+            --linkoptions "-Wl,-mllvm,-threads=4"
+            buildoptions "-flto"
+            linkoptions "-flto"
+        auFilter{}
+    end
+end
+
+local function auBlockProjectKeyLtoMsvc(processor, value)
+    if (value) then
+        auFilter{"toolset:msc"}
+            --linkoptions "/LTCG"
+            flags { "LinkTimeOptimization" }
+            flags { "NoIncrementalLink" }
+            buildoptions "/GL"
+        auFilter{}
+    end
+end
+
+local function auBlockProjectKeyLtoClang(processor, value)
+    auBlockProjectKeyLtoNotMsvc(processor, value)
+end
+
+local function auBlockProjectKeyLtoNotClang(processor, value)
+    auBlockProjectKeyLtoMsvc(processor, value)
+end
+
+local function auBlockProjectKeyLto(processor, value)
+    auBlockProjectKeyLtoMsvc(processor, value)
+    auBlockProjectKeyLtoNotMsvc(processor, value)
+end
+
 auProjectBlockHandlers = 
 {
     links = auBlockProjectKeyLinks,
@@ -489,7 +524,12 @@ auProjectBlockHandlers =
     unpack = auBlockProjectKeyUnpack,
     m4 = auBlockProjectKeyM4,
     bigObject = auBlockProjectKeyBigObject,
-    rtti = auBlockProjectKeyRtti
+    rtti = auBlockProjectKeyRtti,
+    lto = auBlockProjectKeyLto,
+    ltoNotMsvc = auBlockProjectKeyLtoNotMsvc,
+    ltoNotClang = auBlockProjectKeyLtoNotClang,
+    ltoMsvc = auBlockProjectKeyLtoMsvc,
+    ltoClang = auBlockProjectKeyLtoClang
 }
 auProjectBlockHandlers["soft-depends"] = auBlockProjectKeySoftDepends
 
@@ -520,7 +560,8 @@ kGenericTasks = {
                     "msvcIgnore",  "excludes", "depends", "require", "m4", "vala",
                     "eval", "lua", "events", "actions", "staticImpDefines", "features",
                     "links", "soft-depends", "resourceScript", "protobuf", "unpack",
-                    "bigObject", "rtti"
+                    "bigObject", "rtti", "lto", "ltoNotMsvc", "ltoNotClang", "ltoMsvc",
+                    "ltoClang"
                 }
                        
 local kReferenceTasks = {"eval", "includes", "defines", "include", "includes", "protobuf", "actions"} --, "features"}