Nick Fitzgerald

Investigate fuzzing with `cargo fuzz`

1

https://github.com/rust-fuzz/cargo-fuzz Uses `libFuzzer` behind the scenes. Unsure if this is really worth it, hence "investigate" rather than "use". `libFuzzer` is pretty much throwing random bytes (whose next generations are then...

clang::Cursor should never be the null cursor

5

Right now we have various methods on `clang::Cursor` that return `Option`s just because (I think?) we call underlying clang functions that return null if the cursor is the "null cursor"...

Census of binaryen/`wasm-opt` passes that might be relevant to Cranelift

2

What is Cranelift's job (in the context of Wasmtime)? To take Wasm that is produced by LLVM and already optimized 99% of the time and do the architecture-specific code generation...

wasmtime: Add a config knob to control the maximum number of stack frames captured in a backtrace

2

Would make capturing a backtrace go from `O(n)` where `n` is the number of Wasm frames on the stack to constant time for some user-defined acceptable constant. Max frames could...

cranelift: investigate using union find when resolving value aliases

1

A not-insignificant portion of compilation time is spent in lowering, and when you start expanding the call tree, a lot of that time semi-surprisingly ends up being in `value_def`. `value_def`...

Attach binary executables to releases?

1

Sometimes building racer breaks because of nightly stuff (e.g. nightly-2020-07-16 doesn't build racer 2.1.35). It would be cool if the latest tagged releases had prebuilt binary executables for linux/macos/windows attached....

racer-find-definition does not work with macros

4

### Steps to reproduce: - Open a rust source file in emacs with racer mode - Position the cursor over `try` in a `try!(...)` macro invocation - Do `M-.` (aka...

Builds on top of https://github.com/bytecodealliance/wasmtime/pull/5177

Cranelift: shrink the size of `SigData` further

4

This could maybe give us some small perf gains due to a smaller working set that better fits in cache. `SigData` is defined here: https://cs.github.com/bytecodealliance/wasmtime/blob/348f962d23df0a598ea80629ca6d8e4a158fe153/cranelift/codegen/src/machinst/abi.rs?q=SigData#L601-L627 The two changes we could...

Cranelift: reconsider the `heap_addr` instruction

3

On error condition, does this instruction itself trap or return an address that will trap when accessed? Currently that depends on arbitrary bits of the heap configuration and memory being...