Configurable LTO (#4755)

CMakeLists.txt

@@ -97,11 +97,11 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
-# The need for speed (in Release)
-include(CheckIPOSupported)
-check_ipo_supported(RESULT IPO_SUPPORTED)
-if(IPO_SUPPORTED)
-	set(CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE ON)
+# The need for speed (in Release):
+if(WHOLE_PROGRAM_OPTIMISATION)
+	include(CheckIPOSupported)
+	check_ipo_supported(RESULT IPO_SUPPORTED)
+	set(CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE ${IPO_SUPPORTED})
 endif()
 
 # Static CRT

travisbuild.sh

@@ -20,12 +20,13 @@ if [ `which ccache` ]; then
 	ccache -z # Zero statistics
 fi
 
-# Work around a Clang + ccache issue with failing
-# builds by disabling precompiled headers
+# Work around a Clang + ccache issue with failing builds by disabling
+# precompiled headers. Turn off LTO for faster build speeds
 cmake . -DBUILD_TOOLS=YES \
         -DPRECOMPILE_HEADERS=NO \
         -DUNITY_BUILDS=${TRAVIS_CUBERITE_UNITY_BUILDS-YES} \
         -DSELF_TEST=YES \
+        -DWHOLE_PROGRAM_OPTIMISATION=No \
         ${CACHE_ARGS};
 
 echo "Building..."