Re:A public TrueCrypt Audit
by epsylon on Thursday October 10, 2013 @02:09AM
(#6525945)
In the debian fiasco it's mostly a case of "manual code elimination" [1].
However there are plenty of examples of compilers aggressively removing code that causes undefined behaviour. Basically, when the compiler encounters UB, it can do whatever it wants to code that triggers the UB, which means possibly removing it. Compilers exploit this fact a lot because UBs happen a lot in "normal code". See here [2] for examples and explanations; I also can't help but mention John Regehr's blog [3] if you're interested in compilers, security, testing, safety.
However there are plenty of examples of compilers aggressively removing code that causes undefined behaviour. Basically, when the compiler encounters UB, it can do whatever it wants to code that triggers the UB, which means possibly removing it. Compilers exploit this fact a lot because UBs happen a lot in "normal code". See here [2] for examples and explanations; I also can't help but mention John Regehr's blog [3] if you're interested in compilers, security, testing, safety.
[1] http://research.swtch.com/openssl
[2] http://blog.llvm.org/2011/05/what-every-c-programmer-should-...
[3] http://blog.regehr.org/archives/213 is a great article for example.