cmake: Check -flto flags

We should check if -flto-partition=none is defined when the compiler
does not support symver attribute and fail the build if it is not.

Fixes: https://tracker.ceph.com/issues/40060
Co-authored-by: Kefu Chai <tchaikov@gmail.com>
Signed-off-by: Boris Ranto <branto@redhat.com>

diff --git a/cmake/modules/CephChecks.cmake b/cmake/modules/CephChecks.cmake
index 4317e4f4eec1ddba0b778de4d7537bf2304b0acb..01e1c7695e5c746a6141fc13d05ffc25f29e961a 100644 (file)
--- a/cmake/modules/CephChecks.cmake
+++ b/cmake/modules/CephChecks.cmake
@@ -155,6 +155,12 @@ __attribute__((__symver__ (\"func@v2\"))) void func_v2() {};
 
 int main() {}"
   HAVE_ATTR_SYMVER)
+  if(NOT HAVE_ATTR_SYMVER)
+    if(CMAKE_CXX_FLAGS MATCHES "-flto" AND NOT CMAKE_CXX_FLAGS MATCHES "-flto-partition=none")
+      # https://tracker.ceph.com/issues/40060
+      message(FATAL_ERROR "please pass -flto-partition=none as part of CXXFLAGS")
+    endif()
+  endif()
 set(CMAKE_REQUIRED_FLAGS -Wl,--version-script=${CMAKE_CURRENT_BINARY_DIR}/version_script.txt)
 check_c_source_compiles("
 void func_v1() {}