MDEV-17703 Add WITH_UBSAN switch to CMake similar to WITH_ASAN

This can be useful:
UBSAN_OPTIONS=log_path=/some/path

clang users may want to increase stack size in include/my_pthread.h or enable
some optimizations

CMakeLists.txt

@@ -214,6 +214,15 @@ IF (WITH_ASAN)
   ENDIF()
 ENDIF()
 
+OPTION(WITH_UBSAN "Enable undefined behavior sanitizer" OFF)
+IF (WITH_UBSAN)
+  IF(SECURITY_HARDENED)
+    MESSAGE(FATAL_ERROR "WITH_UBSAN and SECURITY_HARDENED are mutually exclusive")
+  ENDIF()
+  MY_CHECK_AND_SET_COMPILER_FLAG("-fsanitize=undefined" DEBUG RELWITHDEBINFO)
+ENDIF()
+
+
 # enable security hardening features, like most distributions do
 # in our benchmarks that costs about ~1% of performance, depending on the load
 IF(CMAKE_C_COMPILER_VERSION VERSION_LESS "4.6")

cmake/os/Linux.cmake

@@ -35,7 +35,7 @@ ENDFOREACH()
 # Ensure we have clean build for shared libraries
 # without unresolved symbols
 # Not supported with AddressSanitizer
-IF(NOT WITH_ASAN)
+IF(NOT WITH_ASAN AND NOT WITH_UBSAN)
   SET(LINK_FLAG_NO_UNDEFINED "-Wl,--no-undefined")
 ENDIF()
 

cmake/plugin.cmake

@@ -209,7 +209,7 @@ MACRO(MYSQL_ADD_PLUGIN)
       ELSEIF(NOT CMAKE_SYSTEM_NAME STREQUAL "Linux")
         TARGET_LINK_LIBRARIES (${target} mysqld)
       ENDIF()
-    ELSEIF(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND NOT WITH_ASAN)
+    ELSEIF(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND NOT WITH_ASAN AND NOT WITH_UBSAN)
       TARGET_LINK_LIBRARIES (${target} "-Wl,--no-undefined")
     ENDIF()