[llvm-dev] Undefined behaviour in command line parser

[Renato Golin via llvm-dev]

Hi Lorenzo,

Thanks for the report. Can you create a new entry in Bugzilla? With
steps to reproduce (command line options, etc) and how you're getting
the value of the triple (debugger?).

http://llvm.org/bugs/

cheers,
--renato

On 27 March 2016 at 17:15, Lorenzo Laneve via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> In these days I’ve integrated llc code into my compiler.
>
> I had an undefined behaviour because when
> cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion)
> is called, the modules I give to the code in input to compile got somehow
> “corrupted" by this function.
> It is definitely an undefined behaviour because every debug I do, modules
> gets different changes, producing different assertions every run:
>
> - Target triple string gets changes with null characters
> (“\0\0\0\0\0\0\0\0\0\0\0”), or other values that have nothing to do with an
> llvm triple
> - Head of the function list contained in the module becomes NULL (I said
> functions but maybe other components may be nullified as well)
>
> I tried to see where the modules change, and I figured out that 6/10 times
> the target triple is ok before that instruction, then it takes weird changes
> after it.
> The problem is that function because when I removed it, everything worked
> fine.
>
> I didn't figure out how that function may change modules that way, so I just
> report this bug here.
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>