cmake: remove _FORTIFY_SOURCE define

according to `dpkg-buildflags`, ubuntu 24 raised this value to
`-D_FORTIFY_SOURCE=3` which causes `error: "_FORTIFY_SOURCE" redefined`
compilation failures because Ceph itself adds `-D_FORTIFY_SOURCE=2`

`_FORTIFY_SOURCE` is a hardening option. both our rpm and debian builds
already specify that via environment variables, so Ceph's cmake should
leave it alone

Fixes: https://tracker.ceph.com/issues/72361
Signed-off-by: Casey Bodley <cbodley@redhat.com>

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a851c25312cd779f96841c3997d2bd6988693910..3194054286bc9a2389d0483fda4f319f0cc3e855 100644 (file)
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -200,14 +200,6 @@ endif()
 
 include(CheckCCompilerFlag)
 if(CMAKE_CXX_COMPILER_ID STREQUAL GNU)
-  CHECK_C_COMPILER_FLAG("-U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2" HAS_FORTIFY_SOURCE)
-  if(NOT CMAKE_BUILD_TYPE STREQUAL Debug)
-    if(HAS_FORTIFY_SOURCE)
-      add_definitions(
-        -U_FORTIFY_SOURCE
-        -D_FORTIFY_SOURCE=2)
-    endif()
-  endif()
     CHECK_C_COMPILER_FLAG(-fstack-protector-strong HAS_STACK_PROTECT)
     if (HAS_STACK_PROTECT)
       add_compile_options(-fstack-protector-strong)