Andrew Brown (Nov 18 2020 at 17:33): Andrew Brown (Nov 18 2020 at 17:33):@Alex Crichton, @Dan Gohman, I think I found a bug but I don't know exactly where things are going wrong: I hash the contents of a file and emit the result, but the result is different when I run the program as a rustc-compiled binary and as a wasm32-wasi file run in Wasmtime. Any ideas?
Andrew Brown (Nov 18 2020 at 17:34):I created an example here: https://github.com/abrown/hashing-example
Alex Crichton (Nov 18 2020 at 17:34):hm that repo is a 404, but what hash algorithm are you using?
Andrew Brown (Nov 18 2020 at 17:35):sorry, just made it public
Alex Crichton (Nov 18 2020 at 17:36):ah yeah the Hash trait is not architecture-independent
Alex Crichton (Nov 18 2020 at 17:36):it hashes usize differently on 32 and 64-bit platforms
Andrew Brown (Nov 18 2020 at 17:36):ooooh
Andrew Brown (Nov 18 2020 at 17:37):so if I get rid of the trait and do the hashing manually I should get the same result, right?
Alex Crichton (Nov 18 2020 at 17:38):you should yeah
Andrew Brown (Nov 18 2020 at 17:39):hooray! solved.
Andrew Brown (Nov 18 2020 at 17:39):thanks, deleting the repo now :smile:
Dan Gohman (Nov 18 2020 at 17:40):Where does it hash a usize? Does Hash implicitly hash the length of a slice?
Dan Gohman (Nov 18 2020 at 17:42):Aha, perhaps it does: https://doc.rust-lang.org/stable/src/core/hash/mod.rs.html#669
Dan Gohman (Nov 18 2020 at 17:43):Which suggests that a way to avoid that would be to call hash_slice instead.
Alex Crichton (Nov 18 2020 at 18:00):ah yeah it's in hashing slices which hashes the length
Last updated: Nov 22 2024 at 16:03 UTC