Re: [kvm-unit-tests PATCH v3 1/7] lib: Add pseudo random functions

[Nina Schoetterl-Glausch <nsg@linux.ibm.com>]

On Tue, 2024-06-25 at 13:08 +1000, Nicholas Piggin wrote:
> On Fri Jun 21, 2024 at 12:16 AM AEST, Nina Schoetterl-Glausch wrote:

[...]

> >     I tested the implementation in the following way:
> >     
> >     cat <<'EOF' > rand.py
> >     #!/usr/bin/python3
> >     
> >     def prng32(seed):
> >         from hashlib import sha256
> >         state = seed.to_bytes(8, byteorder="big")
> >         while True:
> >             state = sha256(state).digest()
> >             for i in range(8):
> >                 yield int.from_bytes(state[i*4:(i+1)*4], byteorder="big")
> >     
> >     r = prng32(0)
> >     for i in range(100):
> >         print(f"{next(r):08x}")
> >     
> >     EOF
> >     
> >     cat <<'EOF' > rand.c
> >     #include <stdio.h>
> >     #include "rand.h"
> >     
> >     void main(void)
> >     {
> >     	prng_state state = prng_init(0);
> >     	for (int i = 0; i < 100; i++) {
> >     		printf("%08x\n", prng32(&state));
> >     	}
> >     }
> >     EOF
> >     cat <<'EOF' > libcflat.h
> >     #define ARRAY_SIZE(_a) (sizeof(_a)/sizeof((_a)[0]))
> >     EOF
> >     chmod +x rand.py
> >     ln -s lib/rand.c librand.c
> >     gcc -Ilib librand.c rand.c
> >     diff <(./a.out) <(./rand.py)
> 
> Cool... you made a unit test for the unit tests. We could start a
> make check? :)

I wouldn't complain about it, but my test is a bit hacky and I don't
expect the code to get touched much.
> 
> Acked-by: Nicholas Piggin <npiggin@gmail.com>
> 
> Thanks,
> Nick