On Wed, Oct 18, 2017 at 11:00:30AM +0200, Martin Liška wrote: > Hi. > > I would like to use this thread to slightly describe differences in GCC and > LLVM. > I compared options support by both and: > > UBSAN: > > 1) > gcc: error: unrecognized argument to -fsanitize= option: ‘nullability-arg’ > gcc: error: unrecognized argument to -fsanitize= option: ‘nullability-assign’ > gcc: error: unrecognized argument to -fsanitize= option: ‘nullability-return’
I believe those are for diagnostic of some Objective-C addition, some _Nullable and _Nonnull keywords on (pointer) types. Seems LLVM supports it as an extension even for C/C++. > I guess it's covered by -fsanitize=nonnull-attribute and > -fsanitize=returns-nonnull-attribute. > One can't have in GCC a local variable with non-null attribute > (nullability-assign), right? > > 2) unsigned-integer-overflow > > As documented, not being a real UBSAN. Do we want that or seen as not useful? This one is not implemented on purpose, it doesn't make any sense to me. > 3) function > > Indirect function pointer comparison using RTTI in C++. Would it be useful? > Ideas? Dunno what this one is about. 4) builtin Which I've posted yesterday patch for. > ASAN: > > For ASAN, there's quite up-to-date page: > https://github.com/google/sanitizers/wiki/AddressSanitizerClangVsGCC-(5.0-vs-7.1) > > The page is quite up-to-date. Currently we should cover all what LLVM > supports. Am I right? Or is there any interesting > feature we miss? As I said on IRC, we probably should be redirecting at sanopt or asan pass __builtin_memcpy etc. calls to __asan_memcpy etc. Jakub
