Thanks for the answer. > but it looks like there's a bug in the option's specification that > prevents invalid (non-numeric) arguments from being diagnosed, making > GCC accept anything (including negative numbers). > True, it accept strings and negative decimal numbers and hexadecimal numbers and even gives me identical binaries... So you would say that the only valid parameter to -frandom-seed is an unsigned decimal number? -frandom-seed=18464 // correct -frandom-seed=a48cb9 //wrong -frandom-seed=foobar //wrong Regards, Stephan