build: configure LTO

Related-To: NEO-9328
Signed-off-by: Artur Harasimiuk <artur.harasimiuk@intel.com>

CMakeLists.txt

@@ -173,6 +173,25 @@ endif()
 
 include(CheckCXXCompilerFlag)
 if(UNIX)
+  if(${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU" AND(
+                                                   ${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 9.0 OR
+                                                   (${CMAKE_CXX_COMPILER_VERSION} VERSION_GREATER_EQUAL 12.0 AND ${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 13.0
+    )))
+    message(STATUS "Disabling LTO because compiler is ${CMAKE_CXX_COMPILER_ID} v${CMAKE_CXX_COMPILER_VERSION}")
+    set(NEO_DISABLE_LTO TRUE)
+  endif()
+  if(NOT NEO_DISABLE_LTO)
+    check_cxx_compiler_flag("-flto=auto" COMPILER_SUPPORTS_FLTO_AUTO)
+    if(COMPILER_SUPPORTS_FLTO_AUTO)
+      message(STATUS "enabling lto=auto, disabling ld.lld")
+      set(NEO_DISABLE_LD_LLD TRUE)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -flto=auto")
+      check_cxx_compiler_flag("-ffat-lto-objects" COMPILER_SUPPORTS_FAT_LTO_OBJECTS)
+      if(COMPILER_SUPPORTS_FAT_LTO_OBJECTS)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ffat-lto-objects")
+      endif()
+    endif()
+  endif()
   find_program(__LD_GOLD_FOUND ld.gold)
   find_program(__LD_LLD_FOUND ld.lld)
   check_cxx_compiler_flag(-fuse-ld=lld COMPILER_SUPPORTS_LLD)

manifests/manifest.yml

@@ -31,7 +31,7 @@ components:
     branch: master
     dest_dir: infra
     fetch_tags: true
-    revision: v5813
+    revision: v5818
     type: git
   internal:
     branch: master