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#[macro_use]
30pub(crate) mod func;
31
32pub(crate) mod code;
33pub(crate) mod code_memory;
34#[cfg(feature = "debug-builtins")]
35pub(crate) mod debug;
36pub(crate) mod externals;
37pub(crate) mod gc;
38pub(crate) mod instance;
39pub(crate) mod instantiate;
40pub(crate) mod limits;
41pub(crate) mod linker;
42pub(crate) mod memory;
43pub(crate) mod module;
44pub(crate) mod resources;
45pub(crate) mod store;
46pub(crate) mod trampoline;
47pub(crate) mod trap;
48pub(crate) mod type_registry;
49pub(crate) mod types;
50pub(crate) mod uninhabited;
51pub(crate) mod v128;
52pub(crate) mod values;
53pub(crate) mod vm;
54
55#[cfg(feature = "component-model")]
56pub mod component;
57
58cfg_if::cfg_if! {
59    if #[cfg(miri)] {
60        // no extensions on miri
61    } else if #[cfg(unix)] {
62        pub mod unix;
63    } else if #[cfg(windows)] {
64        pub mod windows;
65    } else {
66        // ... unknown os!
67    }
68}
69
70pub use code_memory::CodeMemory;
71pub use externals::*;
72pub use func::*;
73pub use gc::*;
74pub use instance::{Instance, InstancePre};
75pub use instantiate::CompiledModule;
76pub use limits::*;
77pub use linker::*;
78pub use memory::*;
79pub use module::{Module, ModuleExport};
80pub use resources::*;
81#[cfg(all(feature = "async", feature = "call-hook"))]
82pub use store::CallHookHandler;
83pub use store::{
84    AsContext, AsContextMut, CallHook, Store, StoreContext, StoreContextMut, UpdateDeadline,
85};
86pub use trap::*;
87pub use types::*;
88pub use v128::V128;
89pub use values::*;
90
91pub(crate) use uninhabited::*;
92
93#[cfg(feature = "pooling-allocator")]
94pub use vm::PoolConcurrencyLimitError;
95
96#[cfg(feature = "profiling")]
97mod profiling;
98#[cfg(feature = "profiling")]
99pub use profiling::GuestProfiler;
100
101#[cfg(feature = "async")]
102pub(crate) mod stack;
103#[cfg(feature = "async")]
104pub use stack::*;
105
106#[cfg(feature = "coredump")]
107mod coredump;
108#[cfg(feature = "coredump")]
109pub use coredump::*;
110
111#[cfg(feature = "wave")]
112mod wave;
113
114fn _assertions_runtime() {
115    use crate::_assert_send_and_sync;
116
117    #[cfg(feature = "async")]
118    fn _assert_send<T: Send>(_t: T) {}
119
120    _assert_send_and_sync::<Caller<'_, ()>>();
121    _assert_send_and_sync::<ExternRef>();
122    _assert_send_and_sync::<(Func, TypedFunc<(), ()>, Global, Table, Memory)>();
123    _assert_send_and_sync::<Instance>();
124    _assert_send_and_sync::<InstancePre<()>>();
125    _assert_send_and_sync::<InstancePre<*mut u8>>();
126    _assert_send_and_sync::<Linker<()>>();
127    _assert_send_and_sync::<Linker<*mut u8>>();
128    _assert_send_and_sync::<Module>();
129    _assert_send_and_sync::<Store<()>>();
130    _assert_send_and_sync::<StoreContext<'_, ()>>();
131    _assert_send_and_sync::<StoreContextMut<'_, ()>>();
132
133    #[cfg(feature = "async")]
134    fn _call_async(s: &mut Store<()>, f: Func) {
135        _assert_send(f.call_async(&mut *s, &[], &mut []))
136    }
137    #[cfg(feature = "async")]
138    fn _typed_call_async(s: &mut Store<()>, f: TypedFunc<(), ()>) {
139        _assert_send(f.call_async(&mut *s, ()))
140    }
141    #[cfg(feature = "async")]
142    fn _instantiate_async(s: &mut Store<()>, m: &Module) {
143        _assert_send(Instance::new_async(s, m, &[]))
144    }
145}
wasmtime/runtime.rs

wasmtime/
runtime.rs
