Use LTO for linux as well

eng/native/configurecompiler.cmake

@@ -15,6 +15,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 include(CheckLinkerFlag)
+include(CheckIPOSupported)
 
 # "configureoptimization.cmake" must be included after CLR_CMAKE_HOST_UNIX has been set.
 include(${CMAKE_CURRENT_LIST_DIR}/configureoptimization.cmake)
@@ -152,6 +153,17 @@ elseif (CLR_CMAKE_HOST_UNIX)
   endif()
 endif(MSVC)
 
+check_ipo_supported(RESULT result OUTPUT output)
+if(result AND NOT CLR_CMAKE_TARGET_APPLE)
+  # Apple does not properly support IPO and need more involved
+  # way on how to support this. For now, disable it for Apple.
+  set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
+  set(CMAKE_INTERPROCEDURAL_OPTIMIZATION_DEBUG OFF)
+  set(CMAKE_INTERPROCEDURAL_OPTIMIZATION_CHECKED OFF)
+else()
+  message(WARNING "IPO is not supported")
+endif()
+
 if (CLR_CMAKE_ENABLE_SANITIZERS)
   set (CLR_CMAKE_BUILD_SANITIZERS "")
   set (CLR_CMAKE_SANITIZER_RUNTIMES "")
@@ -889,10 +901,6 @@ if (MSVC)
     add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/Gz>)
   endif (CLR_CMAKE_HOST_ARCH_I386)
 
-  set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
-  set(CMAKE_INTERPROCEDURAL_OPTIMIZATION_DEBUG OFF)
-  set(CMAKE_INTERPROCEDURAL_OPTIMIZATION_CHECKED OFF)
-
   if (CLR_CMAKE_HOST_ARCH_AMD64)
     # The generator expression in the following command means that the /homeparams option is added only for debug builds for C and C++ source files
     add_compile_options($<$<AND:$<CONFIG:Debug>,$<COMPILE_LANGUAGE:C,CXX>>:/homeparams>) # Force parameters passed in registers to be written to the stack

src/coreclr/debug/runtimeinfo/CMakeLists.txt

@@ -61,6 +61,8 @@ else()
   target_include_directories(cdac_data_descriptor BEFORE PRIVATE ${VM_DIR})
   target_include_directories(cdac_data_descriptor BEFORE PRIVATE ${VM_DIR}/${ARCH_SOURCES_DIR})
   target_include_directories(cdac_data_descriptor PRIVATE ${CLR_DIR}/interop/inc)
+  # LTO not supported for cdac, so disable it
+  set_target_properties(cdac_data_descriptor  PROPERTIES INTERPROCEDURAL_OPTIMIZATION OFF)
 
   set(GENERATED_CDAC_DESCRIPTOR_DIR "${CMAKE_CURRENT_BINARY_DIR}/cdac")
   set(CONTRACT_DESCRIPTOR_OUTPUT "${GENERATED_CDAC_DESCRIPTOR_DIR}/contract-descriptor.c")

src/coreclr/nativeaot/CMakeLists.txt

@@ -7,13 +7,13 @@ if(MSVC)
   set_property(DIRECTORY PROPERTY CLR_EH_OPTION /EHa-s-)   # Native AOT runtime does not use C++ exception handling
   set_property(DIRECTORY PROPERTY CLR_CONTROL_FLOW_GUARD OFF)
 
-  # The code generated by the Native AOT compiler doesn't work with Link Time Code Generation
-  set(CMAKE_INTERPROCEDURAL_OPTIMIZATION OFF)
-
   # Sets the options that create the fastest code in the majority of cases
   add_compile_options($<$<AND:$<COMPILE_LANGUAGE:C,CXX>,$<CONFIG:Release>>:/O2>)
 endif (MSVC)
 
+# The code generated by the Native AOT compiler doesn't work with Link Time Code Generation
+set(CMAKE_INTERPROCEDURAL_OPTIMIZATION OFF)
+
 if(CLR_CMAKE_HOST_UNIX)
   add_compile_options(-fno-exceptions)    # Native AOT runtime doesn't use C++ exception handling
   add_compile_options(-fno-asynchronous-unwind-tables)