wasmtime/
runtime.rs

1// Wasmtime's runtime has lots of fiddly bits where we're doing operations like
2// casting between wasm i32/i64 and host `usize` values. There's also in general
3// just lots of pieces of low-level manipulation of memory and internals of VM
4// runtime state. To help keep all the integer casts correct be a bit more
5// strict than the default settings to help weed out bugs ahead of time.
6//
7// This inevitably leads to wordier code than might otherwise be used because,
8// for example, `u64 as usize` is warned against and will be an error on CI.
9// This happens pretty frequently and needs to be replaced with `val.try_into()`
10// or `usize::try_from(val)` where the error is handled. In some cases the
11// correct thing to do is to `.unwrap()` the error to indicate a fatal mistake,
12// but in some cases the correct thing is to propagate the error.
13//
14// Some niche cases that explicitly want truncation are recommended to have a
15// function along the lines of
16//
17//     #[allow(clippy::cast_possible_truncation)]
18//     fn truncate_i32_to_i8(a: i32) -> i8 { a as i8 }
19//
20// as this explicitly indicates the intent of truncation is desired. Other
21// locations should use fallible conversions.
22//
23// If performance is absolutely critical then it's recommended to use `#[allow]`
24// with a comment indicating why performance is critical as well as a short
25// explanation of why truncation shouldn't be happening at runtime. This
26// situation should be pretty rare though.
27#![warn(clippy::cast_possible_truncation)]
28
29#[cfg(feature = "component-model-async")]
30mod bug;
31
32#[macro_use]
33pub(crate) mod func;
34
35pub(crate) mod code;
36pub(crate) mod code_memory;
37#[cfg(feature = "debug")]
38pub(crate) mod debug;
39#[cfg(feature = "gc")]
40pub(crate) mod exception;
41pub(crate) mod externals;
42#[cfg(feature = "async")]
43pub(crate) mod fiber;
44pub(crate) mod gc;
45pub(crate) mod instance;
46pub(crate) mod instantiate;
47pub(crate) mod limits;
48pub(crate) mod linker;
49pub(crate) mod memory;
50pub(crate) mod module;
51#[cfg(feature = "debug-builtins")]
52pub(crate) mod native_debug;
53pub(crate) mod resources;
54pub(crate) mod store;
55pub(crate) mod trampoline;
56pub(crate) mod trap;
57pub(crate) mod type_registry;
58pub(crate) mod types;
59pub(crate) mod v128;
60pub(crate) mod values;
61pub(crate) mod vm;
62
63#[cfg(feature = "component-model")]
64pub mod component;
65
66cfg_if::cfg_if! {
67    if #[cfg(miri)] {
68        // no extensions on miri
69    } else if #[cfg(not(feature = "std"))] {
70        // no extensions on no-std
71    } else if #[cfg(unix)] {
72        pub mod unix;
73    } else if #[cfg(windows)] {
74        pub mod windows;
75    } else {
76        // ... unknown os!
77    }
78}
79
80#[cfg(feature = "component-model-async")]
81pub use bug::WasmtimeBug;
82#[cfg(feature = "component-model-async")]
83pub(crate) use bug::bail_bug;
84pub use code_memory::CodeMemory;
85#[cfg(feature = "debug")]
86pub use debug::*;
87#[cfg(feature = "gc")]
88pub use exception::*;
89pub use externals::*;
90pub use func::*;
91pub use gc::*;
92pub use instance::{Instance, InstancePre};
93pub use instantiate::CompiledModule;
94pub use limits::*;
95pub use linker::*;
96pub use memory::*;
97pub use module::{Module, ModuleExport};
98pub use resources::*;
99#[cfg(all(feature = "async", feature = "call-hook"))]
100pub use store::CallHookHandler;
101pub use store::{
102    AsContext, AsContextMut, CallHook, Store, StoreContext, StoreContextMut, UpdateDeadline,
103};
104pub use trap::*;
105pub use types::*;
106pub use v128::V128;
107pub use values::*;
108
109#[cfg(feature = "pooling-allocator")]
110pub use vm::{PoolConcurrencyLimitError, PoolingAllocatorMetrics};
111
112#[cfg(feature = "profiling")]
113mod profiling;
114#[cfg(feature = "profiling")]
115pub use profiling::GuestProfiler;
116
117#[cfg(feature = "async")]
118pub(crate) mod stack;
119#[cfg(feature = "async")]
120pub use stack::*;
121
122#[cfg(feature = "coredump")]
123mod coredump;
124#[cfg(feature = "coredump")]
125pub use coredump::*;
126
127#[cfg(feature = "wave")]
128mod wave;
129
130fn _assertions_runtime() {
131    use crate::_assert_send_and_sync;
132
133    #[cfg(feature = "async")]
134    fn _assert_send<T: Send>(_t: T) {}
135
136    _assert_send_and_sync::<Caller<'_, ()>>();
137    _assert_send_and_sync::<ExternRef>();
138    _assert_send_and_sync::<(Func, TypedFunc<(), ()>, Global, Table, Memory)>();
139    _assert_send_and_sync::<Instance>();
140    _assert_send_and_sync::<InstancePre<()>>();
141    _assert_send_and_sync::<InstancePre<*mut u8>>();
142    _assert_send_and_sync::<Linker<()>>();
143    _assert_send_and_sync::<Linker<*mut u8>>();
144    _assert_send_and_sync::<Module>();
145    _assert_send_and_sync::<Store<()>>();
146    _assert_send_and_sync::<StoreContext<'_, ()>>();
147    _assert_send_and_sync::<StoreContextMut<'_, ()>>();
148
149    #[cfg(feature = "async")]
150    fn _call_async(s: &mut Store<()>, f: Func) {
151        _assert_send(f.call_async(&mut *s, &[], &mut []))
152    }
153    #[cfg(feature = "async")]
154    fn _typed_call_async(s: &mut Store<()>, f: TypedFunc<(), ()>) {
155        _assert_send(f.call_async(&mut *s, ()))
156    }
157    #[cfg(feature = "async")]
158    fn _instantiate_async(s: &mut Store<()>, m: &Module) {
159        _assert_send(Instance::new_async(s, m, &[]))
160    }
161}
wasmtime/runtime.rs

wasmtime/
runtime.rs
