[cfe-dev] [UBsan suppression] implicit-integer-sign-change

[Pascal Cremer via cfe-dev]

I would like to suppress implicit-integer-sign-change warnings which 
encounter in

boost/1_64_0/include/boost/iostreams/filter/gzip.hpp:674:16: runtime 
error: implicit conversion from type 'int' of value 139 (32-bit, signed) 
to type 'char' changed the value to -117 (8-bit, signed)
     #0 0x7fed40b77bc2 in 
boost::iostreams::basic_gzip_compressor<std::allocator<char> 
 >::basic_gzip_compressor(boost::iostreams::gzip_params const&, long)

I tried with this line in my suppressions file (which works great for 
other types of warnings)

implicit-integer-sign-change:/path/to/boost/*

However, I get at runtime:

UndefinedBehaviorSanitizer: failed to parse suppressions

I also reported this on SO a while ago:

https://stackoverflow.com/questions/53466501/c-clang-ubsan-suppression-flag-name

Any help would be much appreciated.