From 65d9509c38604152cf162637956022ecdc741bd6 Mon Sep 17 00:00:00 2001
From: WerWolv <werwolv98@gmail.com>
Date: Sun, 9 Jul 2023 20:34:49 +0200
Subject: [PATCH] build: Add checked option to enable LTO

---
 .github/workflows/build.yml |  6 +++---
 CMakeLists.txt              |  1 +
 cmake/build_helpers.cmake   | 11 +++++++++++
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 04fb53fae..4c80dafa3 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -291,7 +291,7 @@ jobs:
             -DIMHEX_COMMIT_HASH_SHORT="${{env.COMMIT_SHA_SHORT}}"   \
             -DIMHEX_COMMIT_HASH_LONG="${{env.COMMIT_SHA_LONG}}"     \
             -DIMHEX_COMMIT_BRANCH="${{env.COMMIT_BRANCH}}"          \
-            -DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON                 \
+            -DIMHEX_ENABLE_LTO=ON                 \
             ..
           make -j 4 install DESTDIR=DebDir
 
@@ -364,7 +364,7 @@ jobs:
             -DIMHEX_COMMIT_HASH_SHORT="${GITHUB_SHA::7}"  \
             -DIMHEX_COMMIT_HASH_LONG="${GITHUB_SHA}"      \
             -DIMHEX_COMMIT_BRANCH="${GITHUB_REF##*/}"     \
-            -DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON       \
+            -DIMHEX_ENABLE_LTO=ON       \
             -DIMHEX_PLUGINS_IN_SHARE=ON                   \
             -DIMHEX_USE_BUNDLED_CA=ON                     \
             ..
@@ -447,7 +447,7 @@ jobs:
           -DIMHEX_COMMIT_HASH_SHORT="${GITHUB_SHA::7}"  \
           -DIMHEX_COMMIT_HASH_LONG="${GITHUB_SHA}"      \
           -DIMHEX_COMMIT_BRANCH="${GITHUB_REF##*/}"     \
-          -DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON       \
+          -DIMHEX_ENABLE_LTO=ON       \
           ..
           make -j 4 install DESTDIR=installDir
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ddf992380..e3908783f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,6 +10,7 @@ option(IMHEX_PATTERNS_PULL_MASTER "Download latest files from master branch of t
 option(IMHEX_IGNORE_BAD_COMPILER "Allow compiling with an unsupported compiler" OFF)
 option(IMHEX_USE_GTK_FILE_PICKER "Use GTK file picker instead of xdg-desktop-portals" OFF)
 option(IMHEX_DISABLE_STACKTRACE "Disables support for printing stack traces" OFF)
+option(IMHEX_ENABLE_LTO "Enables Link Time Optimizations if possible" OFF)
 
 # Basic compiler and cmake configurations
 set(CMAKE_CXX_STANDARD 23)
diff --git a/cmake/build_helpers.cmake b/cmake/build_helpers.cmake
index f896bac09..ea806a837 100644
--- a/cmake/build_helpers.cmake
+++ b/cmake/build_helpers.cmake
@@ -284,6 +284,17 @@ function(JOIN OUTPUT GLUE)
 endfunction()
 
 macro(configureCMake)
+    # Enable LTO if desired and supported
+    if (IMHEX_ENABLE_LTO)
+        include(CheckIPOSupported)
+
+        check_ipo_supported(RESULT result)
+        if (result)
+            set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
+        else ()
+            message(WARNING "LTO is not supported!")
+        endif ()
+    endif ()
 endmacro()
 
 function(message ${ARGN})