Panic when running Wasm gc program #9669
Description
Thanks so much for working on implementing the gc proposal! When I tested it on my own small language I ran into a panic and managed to minify the example down to:
Test Case
Minimal reproduction:
use std::error::Error; use wasmtime::{Config, Engine, Instance, Module, Store}; fn main() -> Result<(), Box<dyn Error>> { let wat = "\ (module (rec (type (;0;) (func (result i32))) (type (;1;) (array (mut i32))) (type $Point (;2;) (struct (field $xs (mut (ref null 1))))) ) (export \"main\" (func $main)) (func $main (;0;) (type 0) (result i32) (local $p (ref null $Point)) i32.const 0 array.new_fixed 1 1 struct.new $Point local.set $p local.get $p struct.get $Point $xs i32.const 0 i32.const 1 array.set 1 local.get $p struct.get $Point $xs i32.const 0 array.get 1 ) )"; let engine = Engine::new(Config::new().wasm_function_references(true).wasm_gc(true))?; let mut store = Store::new(&engine, ()); let module = Module::new(&engine, wat)?; let instance = Instance::new(&mut store, &module, &[])?; let main_func = instance.get_typed_func::<(), i32>(&mut store, "main")?; let result = main_func.call(&mut store, ())?; println!("Result: {:?}", result); Ok(()) }Panics with:
thread 'main' panicked at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\gc\enabled\drc.rs:238:13: every on-stack gc_ref inside a Wasm frame should have an entry in the VMGcRefActivationsTable; 0x20 is not in the table stack backtrace: 0: std::panicking::begin_panic_handler at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library\std\src\panicking.rs:665 1: core::panicking::panic_fmt at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library\core\src\panicking.rs:74 2: wasmtime::runtime::vm::gc::enabled::drc::DrcHeap::trace at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\gc\enabled\drc.rs:238 3: wasmtime::runtime::vm::gc::enabled::drc::impl$9::collect_increment at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\gc\enabled\drc.rs:719 4: wasmtime::runtime::vm::gc::gc_runtime::GarbageCollection::collect<wasmtime::runtime::vm::gc::enabled::drc::DrcCollection> at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\gc\gc_runtime.rs:682 5: wasmtime::runtime::vm::gc::GcStore::gc at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\gc.rs:68 6: wasmtime::runtime::store::StoreOpaque::gc at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\store.rs:1629 7: wasmtime::runtime::store::impl$17::gc<tuple$<> > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\store.rs:2645 8: wasmtime::runtime::vm::libcalls::gc at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\libcalls.rs:449 9: wasmtime::runtime::vm::libcalls::raw::gc::closure$0::closure$0 at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\libcalls.rs:115 10: wasmtime::runtime::vm::instance::Instance::from_vmctx<enum2$<core::result::Result<u32,anyhow::Error> >,wasmtime::runtime::vm::libcalls::raw::gc::closure$0::closure_env$0> at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\instance.rs:239 11: wasmtime::runtime::vm::libcalls::raw::gc::closure$0 at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\libcalls.rs:113 12: core::panic::unwind_safe::impl$25::call_once<enum2$<core::result::Result<u32,anyhow::Error> >,wasmtime::runtime::vm::libcalls::raw::gc::closure_env$0> at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c\library\core\src\panic\unwind_safe.rs:272 13: std::panicking::try::do_call<core::panic::unwind_safe::AssertUnwindSafe<wasmtime::runtime::vm::libcalls::raw::gc::closure_env$0>,enum2$<core::result::Result<u32,anyhow::Error> > > at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c\library\std\src\panicking.rs:557 14: core::iter::sources::once::impl$0::size_hint<wasmtime_environ::types::WasmSubType> 15: std::panicking::try at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c\library\std\src\panicking.rs:521 16: std::panic::catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<wasmtime::runtime::vm::libcalls::raw::gc::closure_env$0>,enum2$<core::result::Result<u32,anyhow::Error> > > at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c\library\std\src\panic.rs:350 17: wasmtime::runtime::vm::traphandlers::catch_unwind_and_longjmp<enum2$<core::result::Result<u32,anyhow::Error> >,wasmtime::runtime::vm::libcalls::raw::gc::closure_env$0> at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\traphandlers.rs:136 18: wasmtime::runtime::vm::libcalls::raw::gc at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\libcalls.rs:112 19: <unknown> 20: <unknown> 21: <unknown> 22: wasmtime::runtime::func::typed::impl$1::call_raw::closure$0<tuple$<>,i32,tuple$<> > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\func\typed.rs:217 23: wasmtime::runtime::vm::traphandlers::catch_traps::call_closure<wasmtime::runtime::func::typed::impl$1::call_raw::closure_env$0<tuple$<>,i32,tuple$<> > > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\traphandlers.rs:290 24: wasmtime_setjmp_27_0_0 at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\helpers.c:72 25: wasmtime::runtime::vm::traphandlers::catch_traps::closure$1<wasmtime::runtime::func::typed::impl$1::call_raw::closure_env$0<tuple$<>,i32,tuple$<> > > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\traphandlers.rs:267 26: wasmtime::runtime::vm::traphandlers::impl$3::with::closure$0<wasmtime::runtime::vm::traphandlers::catch_traps::closure_env$1<wasmtime::runtime::func::typed::impl$1::call_raw::closure_env$0<tuple$<>,i32,tuple$<> > > > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\traphandlers.rs:414 27: wasmtime::runtime::vm::traphandlers::tls::set<i32,wasmtime::runtime::vm::traphandlers::impl$3::with::closure_env$0<wasmtime::runtime::vm::traphandlers::catch_traps::closure_env$1<wasmtime::runtime::func::typed::impl$1::call_raw::closure_env$0<tuple$<>,i32, at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\traphandlers.rs:790 28: wasmtime::runtime::vm::traphandlers::call_thread_state::CallThreadState::with<wasmtime::runtime::vm::traphandlers::catch_traps::closure_env$1<wasmtime::runtime::func::typed::impl$1::call_raw::closure_env$0<tuple$<>,i32,tuple$<> > > > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\traphandlers.rs:414 29: wasmtime::runtime::vm::traphandlers::catch_traps<wasmtime::runtime::func::typed::impl$1::call_raw::closure_env$0<tuple$<>,i32,tuple$<> > > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\vm\traphandlers.rs:259 30: wasmtime::runtime::func::invoke_wasm_and_catch_traps<tuple$<>,wasmtime::runtime::func::typed::impl$1::call_raw::closure_env$0<tuple$<>,i32,tuple$<> > > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\func.rs:1613 31: wasmtime::runtime::func::typed::TypedFunc<tuple$<>,i32>::call_raw<tuple$<>,i32,tuple$<> > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\func\typed.rs:214 32: wasmtime::runtime::func::typed::TypedFunc<tuple$<>,i32>::call<tuple$<>,i32,ref_mut$<wasmtime::runtime::store::Store<tuple$<> > > > at C:\Users\creek\.cargo\registry\src\index.crates.io-6f17d22bba15001f\wasmtime-27.0.0\src\runtime\func\typed.rs:107 33: nemo::main at .\crates\cli\src\main.rs:34 34: core::ops::function::FnOnce::call_once<enum2$<core::result::Result<tuple$<>,alloc::boxed::Box<dyn$<core::error::Error>,alloc::alloc::Global> > > (*)(),tuple$<> > at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c\library\core\src\ops\function.rs:250 Versions and Environment
Wasmtime version or commit: 27.0.0
Operating system: Verified on Windows and Mac
Architecture: x86_64 and arm64