Compilation Warning under ubuntu 20.04

I get this message during compilation of ART :

[ 11%] Building CXX object rtengine/CMakeFiles/rtengine.dir/
In file included from /usr/include/string.h:495,
from /usr/include/glib-2.0/glib/gtestutils.h:30,
from /usr/include/glib-2.0/glib.h:85,
from /home/serge/programs/code-art/rtengine/
In function ‘void* memcpy(void*, const void*, size_t)’,
inlined from ‘int fread(void*, int, int, IMFILE*)’ at /home/serge/programs/code-art/rtengine/myfile.h:123:16,
inlined from ‘void DCraw::parse_makernote(int, int)’ at /home/serge/programs/code-art/rtengine/
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:34:33: warning: ‘void* __builtin___memcpy_chk(void*, const void*, long unsigned int, long unsigned int)’ specified size between 18446744071562067968 and 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
34 | return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
| ~^~~~~~~~~~~~~~~~~
[ 12%] Building CXX object rtengine/CMakeFiles/rtengine.dir/

Some missing library ?
did not prevent a successful compilation.
thanks for your suggestions.

This is a warning about a potential overflow. I’ll have to take a closer look to understand it though… thanks for reporting!

Thanks Alberto, clearly that does not occur on ubuntu 18.04

I think the reason is that the size parameter passed to memcpy is an int instead of a size_t, so that makes gcc complain about the possibility of a negative size value .