When building ubsan-enabled binaries with the clang toolchain (e.g. on AIX or Linux), we get the following warnings :

warning: unknown warning option '-Wno-stringop-truncation'; did you mean '-Wno-string-concatenation'? [-Wunknown-warning-option]
warning: unknown warning option '-Wno-format-overflow'; did you mean '-Wno-shift-overflow'? [-Wunknown-warning-option]
warning: unknown warning option '-Wno-stringop-overflow'; did you mean '-Wno-shift-overflow'? [-Wunknown-warning-option]