cmake: make possible to enable LTO when compiling dll games

Author: illwieckz

cmake/DaemonFlags.cmake

@@ -68,10 +68,19 @@ macro(set_c_cxx_flag FLAG)
     set_c_flag(${FLAG} ${ARGN})
     set_cxx_flag(${FLAG} ${ARGN})
 endmacro()
+
+macro(set_kind_linker_flag KIND FLAG)
+	if (KIND STREQUAL "exe")
+		set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${FLAG}")
+		set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${FLAG}")
+	else()
+		set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${FLAG}")
+	endif()
+endmacro()
+
 macro(set_linker_flag FLAG)
-    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${FLAG}")
-    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${FLAG}")
-    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${FLAG}")
+	set_kind_linker_flag("exe" FLAG)
+	set_kind_linker_flag("shared" FLAG)
 endmacro()
 
 function(try_flag LIST FLAG)
@@ -142,6 +151,16 @@ macro(try_linker_flag PROP FLAG)
     endif()
 endmacro()
 
+macro(try_kind_linker_flag KIND PROP FLAG)
+    # Check it with the C compiler
+    set(CMAKE_REQUIRED_FLAGS ${FLAG})
+    check_C_compiler_flag(${FLAG} FLAG_${PROP})
+    set(CMAKE_REQUIRED_FLAGS "")
+    if (FLAG_${PROP})
+        set_kind_linker_flag(${KIND} ${FLAG} ${ARGN})
+    endif()
+endmacro()
+
 if (BE_VERBOSE)
     set(WARNMODE "no-error=")
 else()
@@ -335,9 +354,15 @@ else()
 		try_c_cxx_flag(WSTACK_PROTECTOR "-Wstack-protector")
 
 		if (NOT NACL OR (NACL AND GAME_PIE))
-			try_c_cxx_flag(FPIE "-fPIE")
+			if (BUILD_GAME_NATIVE_DLL AND (BUILD_CGAME OR BUILD_SGAME))
+				try_c_cxx_flag(FPIE "-fPIC")
+			else()
+				try_c_cxx_flag(FPIE "-fPIE")
+			endif()
+
 			if (NOT APPLE)
-				try_linker_flag(LINKER_PIE "-pie")
+				try_kind_linker_flag("shared" LINKER_PIE "-pic")
+				try_kind_linker_flag("exe" LINKER_PIE "-pie")
 			endif()
 		endif()