[cfe-dev] recent change broke -fcatch-undefined-behavior

[Jean-Daniel Dupas]

Le 15 oct. 2012 à 19:55, Sean McBride <sean at rogue-research.com> a écrit :

> Hi all,
> 
> I see that there have been recent changes wrt -fcatch-undefined-behavior, and within the last week or so something changed such that my own build of clang (built with CMake on OS X) is unable to build simple programs that use -fcatch-undefined-behavior, I get link errors like:
> 
>  "___ubsan_handle_divrem_overflow", referenced from:
>      _main in test-OSZvjm.o
>  "___ubsan_handle_type_mismatch", referenced from:
>      _main in test-OSZvjm.o
> 
> Any ideas why?
> 

This is a new feature. Instead of generating traps, -fcatch-undefined-behavior generates library calls that make it easier to find what is wrong (each undefined behavior calls a different function).

This functions are provided by the ubsan library that is part of compiler-rt. But I'm not sure the integration to the Makefile build system is done yet.

-- Jean-Daniel