Question regarding undefined reference to functions

[Adhemerval Zanella Netto]

On 01/08/24 13:18, Nik Twerdochlib wrote:
> I am in the process of building two cross compile tool chains and have
> run into a linking issue in both of them.  One tool chain is for armv7
> the other for x86_64.
> 
> The issue I am running into occurs during the linking phase of my software:
> 
>   undefined reference to `_memcpy_s_chk'
>   undefined reference to `sscanf_s'
>   undefined reference to `_strncpy_s_chk'
>   undefined reference to `_sprintf_s_chk'
>   undefined reference to `_strnlen_s_chk'
> 
> My tool chains use glibc 2.28.  Strangely I can not find any
> implementation for these '_s' functions.  A google search for these did
> not lead to anything of value.
> 
> Wondering if anyone on this list would be willing to provide me with any
> information?  I feel there is something I overlooked building the tool
> chains.

The _s variants are from C11 annex K, and there were never implemented in
glibc due multiple issues [1] [2].  

I am not sure *why* are you seeing them while building glibc 2.28; most 
likely the references come from the programs code or some dependency.

[1] https://open-std.org/jtc1/sc22/wg14/www/docs/n1967.htm
[2] https://sourceware.org/legacy-ml/libc-alpha/2014-08/msg00133.html