1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412
use crate::context::Context; use anyhow::Result; use std::cell::RefCell; use std::collections::HashMap; use std::rc::Rc; use std::sync::Arc; use wasmtime_environ::{ ir, settings::{self, Configurable}, }; use wasmtime_jit::{CompilationStrategy, Features}; // Runtime Environment // Configuration /// Global configuration options used to create an [`Engine`] and customize its /// behavior. /// /// This structure exposed a builder-like interface and is primarily consumed by /// [`Engine::new()`] #[derive(Clone)] pub struct Config { pub(crate) flags: settings::Builder, pub(crate) features: Features, pub(crate) debug_info: bool, pub(crate) strategy: CompilationStrategy, } impl Config { /// Creates a new configuration object with the default configuration /// specified. pub fn new() -> Config { let mut flags = settings::builder(); // There are two possible traps for division, and this way // we get the proper one if code traps. flags .enable("avoid_div_traps") .expect("should be valid flag"); Config { debug_info: false, features: Default::default(), flags, strategy: CompilationStrategy::Auto, } } /// Configures whether DWARF debug information will be emitted during /// compilation. /// /// By default this option is `false`. pub fn debug_info(&mut self, enable: bool) -> &mut Self { self.debug_info = enable; self } /// Configures whether the WebAssembly threads proposal will be enabled for /// compilation. /// /// The [WebAssembly threads proposal][threads] is not currently fully /// standardized and is undergoing development. Additionally the support in /// wasmtime itself is still being worked on. Support for this feature can /// be enabled through this method for appropriate wasm modules. /// /// This feature gates items such as shared memories and atomic /// instructions. /// /// This is `false` by default. /// /// [threads]: https://github.com/webassembly/threads pub fn wasm_threads(&mut self, enable: bool) -> &mut Self { self.features.threads = enable; self } /// Configures whether the WebAssembly reference types proposal will be /// enabled for compilation. /// /// The [WebAssembly reference types proposal][proposal] is not currently /// fully standardized and is undergoing development. Additionally the /// support in wasmtime itself is still being worked on. Support for this /// feature can be enabled through this method for appropriate wasm /// modules. /// /// This feature gates items such as the `anyref` type and multiple tables /// being in a module. /// /// This is `false` by default. /// /// [proposal]: https://github.com/webassembly/reference-types pub fn wasm_reference_types(&mut self, enable: bool) -> &mut Self { self.features.reference_types = enable; self } /// Configures whether the WebAssembly SIMD proposal will be /// enabled for compilation. /// /// The [WebAssembly SIMD proposal][proposal] is not currently /// fully standardized and is undergoing development. Additionally the /// support in wasmtime itself is still being worked on. Support for this /// feature can be enabled through this method for appropriate wasm /// modules. /// /// This feature gates items such as the `v128` type and all of its /// operators being in a module. /// /// This is `false` by default. /// /// [proposal]: https://github.com/webassembly/simd pub fn wasm_simd(&mut self, enable: bool) -> &mut Self { self.features.simd = enable; let val = if enable { "true" } else { "false" }; self.flags .set("enable_simd", val) .expect("should be valid flag"); self } /// Configures whether the WebAssembly bulk memory operations proposal will /// be enabled for compilation. /// /// The [WebAssembly bulk memory operations proposal][proposal] is not /// currently fully standardized and is undergoing development. /// Additionally the support in wasmtime itself is still being worked on. /// Support for this feature can be enabled through this method for /// appropriate wasm modules. /// /// This feature gates items such as the `memory.copy` instruction, passive /// data/table segments, etc, being in a module. /// /// This is `false` by default. /// /// [proposal]: https://github.com/webassembly/bulk-memory-operations pub fn wasm_bulk_memory(&mut self, enable: bool) -> &mut Self { self.features.bulk_memory = enable; self } /// Configures whether the WebAssembly multi-value proposal will /// be enabled for compilation. /// /// The [WebAssembly multi-value proposal][proposal] is not /// currently fully standardized and is undergoing development. /// Additionally the support in wasmtime itself is still being worked on. /// Support for this feature can be enabled through this method for /// appropriate wasm modules. /// /// This feature gates functions and blocks returning multiple values in a /// module, for example. /// /// This is `false` by default. /// /// [proposal]: https://github.com/webassembly/multi-value pub fn wasm_multi_value(&mut self, enable: bool) -> &mut Self { self.features.multi_value = enable; self } /// Configures which compilation strategy will be used for wasm modules. /// /// This method can be used to configure which compiler is used for wasm /// modules, and for more documentation consult the [`Strategy`] enumeration /// and its documentation. /// /// The default value for this is `Strategy::Auto`. /// /// # Errors /// /// Some compilation strategies require compile-time options of `wasmtime` /// itself to be set, but if they're not set and the strategy is specified /// here then an error will be returned. pub fn strategy(&mut self, strategy: Strategy) -> Result<&mut Self> { self.strategy = match strategy { Strategy::Auto => CompilationStrategy::Auto, Strategy::Cranelift => CompilationStrategy::Cranelift, #[cfg(feature = "lightbeam")] Strategy::Lightbeam => CompilationStrategy::Lightbeam, #[cfg(not(feature = "lightbeam"))] Strategy::Lightbeam => { anyhow::bail!("lightbeam compilation strategy wasn't enabled at compile time"); } }; Ok(self) } /// Configures whether the debug verifier of Cranelift is enabled or not. /// /// When Cranelift is used as a code generation backend this will configure /// it to have the `enable_verifier` flag which will enable a number of debug /// checks inside of Cranelift. This is largely only useful for the /// developers of wasmtime itself. /// /// The default value for this is `false` pub fn cranelift_debug_verifier(&mut self, enable: bool) -> &mut Self { let val = if enable { "true" } else { "false" }; self.flags .set("enable_verifier", val) .expect("should be valid flag"); self } /// Configures the Cranelift code generator optimization level. /// /// When the Cranelift code generator is used you can configure the /// optimization level used for generated code in a few various ways. For /// more information see the documentation of [`OptLevel`]. /// /// The default value for this is `OptLevel::None`. pub fn cranelift_opt_level(&mut self, level: OptLevel) -> &mut Self { let val = match level { OptLevel::None => "none", OptLevel::Speed => "speed", OptLevel::SpeedAndSize => "speed_and_size", }; self.flags .set("opt_level", val) .expect("should be valid flag"); self } } impl Default for Config { fn default() -> Config { Config::new() } } /// Possible Compilation strategies for a wasm module. /// /// This is used as an argument to the [`Config::strategy`] method. #[non_exhaustive] #[derive(Clone, Debug)] pub enum Strategy { /// An indicator that the compilation strategy should be automatically /// selected. /// /// This is generally what you want for most projects and indicates that the /// `wasmtime` crate itself should make the decision about what the best /// code generator for a wasm module is. /// /// Currently this always defaults to Cranelift, but the default value will /// change over time. Auto, /// Currently the default backend, Cranelift aims to be a reasonably fast /// code generator which generates high quality machine code. Cranelift, /// A single-pass code generator that is faster than Cranelift but doesn't /// produce as high-quality code. /// /// To successfully pass this argument to [`Config::strategy`] the /// `lightbeam` feature of this crate must be enabled. Lightbeam, } /// Possible optimization levels for the Cranelift codegen backend. #[non_exhaustive] #[derive(Clone, Debug)] pub enum OptLevel { /// No optimizations performed, minimizes compilation time by disabling most /// optimizations. None, /// Generates the fastest possible code, but may take longer. Speed, /// Similar to `speed`, but also performs transformations aimed at reducing /// code size. SpeedAndSize, } // Engine /// An `Engine` which is a global context for compilation and management of wasm /// modules. /// /// An engine can be safely shared across threads and is a cheap cloneable /// handle to the actual engine. The engine itself will be deallocate once all /// references to it have gone away. /// /// Engines store global configuration preferences such as compilation settings, /// enabled features, etc. You'll likely only need at most one of these for a /// program. /// /// ## Engines and `Clone` /// /// Using `clone` on an `Engine` is a cheap operation. It will not create an /// entirely new engine, but rather just a new reference to the existing engine. /// In other words it's a shallow copy, not a deep copy. /// /// ## Engines and `Default` /// /// You can create an engine with default configuration settings using /// `Engine::default()`. Be sure to consult the documentation of [`Config`] for /// default settings. #[derive(Default, Clone)] pub struct Engine { pub(crate) config: Arc<Config>, } impl Engine { /// Creates a new [`Engine`] with the specified compilation and /// configuration settings. pub fn new(config: &Config) -> Engine { Engine { config: Arc::new(config.clone()), } } } // Store /// A `Store` is a shared cache of information between WebAssembly modules. /// /// Each `Module` is compiled into a `Store` and a `Store` is associated with an /// [`Engine`]. You'll use a `Store` to attach to a number of global items in /// the production of various items for wasm modules. /// /// # Stores and `Clone` /// /// Using `clone` on a `Store` is a cheap operation. It will not create an /// entirely new store, but rather just a new reference to the existing object. /// In other words it's a shallow copy, not a deep copy. /// /// ## Stores and `Default` /// /// You can create a store with default configuration settings using /// `Store::default()`. This will create a brand new [`Engine`] with default /// ocnfiguration (see [`Config`] for more information). #[derive(Clone)] pub struct Store { // FIXME(#777) should be `Arc` and this type should be thread-safe inner: Rc<StoreInner>, } struct StoreInner { engine: Engine, context: Context, global_exports: Rc<RefCell<HashMap<String, Option<wasmtime_runtime::Export>>>>, signature_cache: RefCell<HashMap<wasmtime_runtime::VMSharedSignatureIndex, ir::Signature>>, } impl Store { /// Creates a new store to be associated with the given [`Engine`]. pub fn new(engine: &Engine) -> Store { Store { inner: Rc::new(StoreInner { engine: engine.clone(), context: Context::new(&engine.config), global_exports: Rc::new(RefCell::new(HashMap::new())), signature_cache: RefCell::new(HashMap::new()), }), } } /// Returns the [`Engine`] that this store is associated with. pub fn engine(&self) -> &Engine { &self.inner.engine } pub(crate) fn context(&self) -> &Context { &self.inner.context } // Specific to wasmtime: hack to pass memory around to wasi #[doc(hidden)] pub fn global_exports( &self, ) -> &Rc<RefCell<HashMap<String, Option<wasmtime_runtime::Export>>>> { &self.inner.global_exports } pub(crate) fn register_wasmtime_signature( &self, signature: &ir::Signature, ) -> wasmtime_runtime::VMSharedSignatureIndex { use std::collections::hash_map::Entry; let index = self.context().compiler().signatures().register(signature); match self.inner.signature_cache.borrow_mut().entry(index) { Entry::Vacant(v) => { v.insert(signature.clone()); } Entry::Occupied(_) => (), } index } pub(crate) fn lookup_wasmtime_signature( &self, type_index: wasmtime_runtime::VMSharedSignatureIndex, ) -> Option<ir::Signature> { self.inner .signature_cache .borrow() .get(&type_index) .cloned() } } impl Default for Store { fn default() -> Store { Store::new(&Engine::default()) } } fn _assert_send_sync() { fn _assert<T: Send + Sync>() {} _assert::<Engine>(); _assert::<Config>(); }