wasmtime_environ/compile/module_types.rs
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526
use crate::{
wasm_unsupported, EngineOrModuleTypeIndex, EntityRef, ModuleInternedRecGroupIndex,
ModuleInternedTypeIndex, ModuleTypes, TypeConvert, TypeIndex, WasmArrayType,
WasmCompositeInnerType, WasmCompositeType, WasmFuncType, WasmHeapType, WasmResult,
WasmStructType, WasmSubType,
};
use std::{borrow::Cow, collections::HashMap, ops::Index};
use wasmparser::{UnpackedIndex, Validator, ValidatorId};
/// A type marking the start of a recursion group's definition.
///
/// This is initialized by `ModuleTypesBuilder::start_rec_group` and then
/// finished in `ModuleTypes::end_rec_group` after all of the types in the rec
/// group have been defined.
struct RecGroupStart {
rec_group_index: ModuleInternedRecGroupIndex,
start: ModuleInternedTypeIndex,
end: ModuleInternedTypeIndex,
}
/// A builder for [`ModuleTypes`].
pub struct ModuleTypesBuilder {
/// The ID of the validator that this builder is configured for. Using a
/// different validator, or multiple validators, with this builder would
/// result in silliness because our `wasmparser::types::*Id`s are only
/// unique within the context of a particular validator. Getting this wrong
/// could result in generating calls to functions of the wrong type, for
/// example. So therefore we always assert that a builder instances is only
/// ever paired with a particular validator context.
validator_id: ValidatorId,
/// The canonicalized and deduplicated set of types we are building.
types: ModuleTypes,
/// The set of trampoline-compatible function types we have already added to
/// `self.types`. We do this additional level of deduping, on top of what
/// `wasmparser` already does, so we can quickly and easily get the
/// trampoline type for a given function type if we've already interned one.
trampoline_types: HashMap<WasmFuncType, ModuleInternedTypeIndex>,
/// A map from already-interned `wasmparser` types to their corresponding
/// Wasmtime type.
wasmparser_to_wasmtime: HashMap<wasmparser::types::CoreTypeId, ModuleInternedTypeIndex>,
/// The set of recursion groups we have already seen and interned.
already_seen: HashMap<wasmparser::types::RecGroupId, ModuleInternedRecGroupIndex>,
/// If we are in the middle of defining a recursion group, this is the
/// metadata about the recursion group we started defining.
defining_rec_group: Option<RecGroupStart>,
}
impl ModuleTypesBuilder {
/// Construct a new `ModuleTypesBuilder` using the given validator.
pub fn new(validator: &Validator) -> Self {
Self {
validator_id: validator.id(),
types: ModuleTypes::default(),
trampoline_types: HashMap::default(),
wasmparser_to_wasmtime: HashMap::default(),
already_seen: HashMap::default(),
defining_rec_group: None,
}
}
/// Reserves space for `amt` more type signatures.
pub fn reserve_wasm_signatures(&mut self, amt: usize) {
self.types.reserve(amt);
self.wasmparser_to_wasmtime.reserve(amt);
self.already_seen.reserve(amt);
}
/// Get the id of the validator that this builder is configured for.
pub fn validator_id(&self) -> ValidatorId {
self.validator_id
}
/// Intern a recursion group and all of its types into this builder.
///
/// If the recursion group has already been interned, then it is reused.
///
/// Panics if given types from a different validator than the one that this
/// builder is associated with.
pub fn intern_rec_group(
&mut self,
validator_types: wasmparser::types::TypesRef<'_>,
rec_group_id: wasmparser::types::RecGroupId,
) -> WasmResult<ModuleInternedRecGroupIndex> {
assert_eq!(validator_types.id(), self.validator_id);
if let Some(interned) = self.already_seen.get(&rec_group_id) {
return Ok(*interned);
}
self.define_new_rec_group(validator_types, rec_group_id)
}
/// Define a new recursion group that we haven't already interned.
fn define_new_rec_group(
&mut self,
validator_types: wasmparser::types::TypesRef<'_>,
rec_group_id: wasmparser::types::RecGroupId,
) -> WasmResult<ModuleInternedRecGroupIndex> {
assert_eq!(validator_types.id(), self.validator_id);
self.start_rec_group(
validator_types,
validator_types.rec_group_elements(rec_group_id),
);
for id in validator_types.rec_group_elements(rec_group_id) {
let ty = &validator_types[id];
let wasm_ty = WasmparserTypeConverter::new(self, |_| {
unreachable!("no need to lookup indexes; we already have core type IDs")
})
.with_rec_group(validator_types, rec_group_id)
.convert_sub_type(ty);
self.wasm_sub_type_in_rec_group(id, wasm_ty);
}
let rec_group_index = self.end_rec_group(rec_group_id);
// Iterate over all the types we just defined and make sure that every
// function type has an associated trampoline type. This needs to happen
// *after* we finish defining the rec group because we may need to
// intern new function types, which would conflict with the contiguous
// range of type indices we pre-reserved for the rec group elements.
for ty in self.rec_group_elements(rec_group_index) {
if self.types[ty].is_func() {
let trampoline = self.intern_trampoline_type(ty);
self.types.set_trampoline_type(ty, trampoline);
}
}
Ok(rec_group_index)
}
/// Get or create the trampoline function type for the given function
/// type. Returns the interned type index of the trampoline function type.
fn intern_trampoline_type(
&mut self,
for_func_ty: ModuleInternedTypeIndex,
) -> ModuleInternedTypeIndex {
let sub_ty = &self.types[for_func_ty];
let trampoline = sub_ty.unwrap_func().trampoline_type();
if let Some(idx) = self.trampoline_types.get(&trampoline) {
// We've already interned this trampoline type; reuse it.
*idx
} else {
// We have not already interned this trampoline type.
match trampoline {
// The trampoline type is the same as the original function
// type. We can reuse the definition and its index, but still
// need to intern the type into our `trampoline_types` map so we
// can reuse it in the future.
Cow::Borrowed(f) => {
self.trampoline_types.insert(f.clone(), for_func_ty);
for_func_ty
}
// The trampoline type is different from the original function
// type. Define the trampoline type and then intern it in
// `trampoline_types` so we can reuse it in the future.
Cow::Owned(f) => {
let idx = self.types.push(WasmSubType {
is_final: true,
supertype: None,
composite_type: WasmCompositeType {
inner: WasmCompositeInnerType::Func(f.clone()),
shared: sub_ty.composite_type.shared,
},
});
// The trampoline type is its own trampoline type.
self.types.set_trampoline_type(idx, idx);
let next = self.types.next_ty();
self.types.push_rec_group(idx..next);
self.trampoline_types.insert(f, idx);
idx
}
}
}
}
/// Start defining a recursion group.
fn start_rec_group(
&mut self,
validator_types: wasmparser::types::TypesRef<'_>,
elems: impl ExactSizeIterator<Item = wasmparser::types::CoreTypeId>,
) {
log::trace!("Starting rec group of length {}", elems.len());
assert!(self.defining_rec_group.is_none());
assert_eq!(validator_types.id(), self.validator_id);
// Eagerly define the reverse map's entries for this rec group's types
// so that we can use them when converting `wasmparser` types to our
// types.
let len = elems.len();
for (i, wasmparser_id) in elems.enumerate() {
let interned = ModuleInternedTypeIndex::new(self.types.len_types() + i);
log::trace!(
"Reserving {interned:?} for {wasmparser_id:?} = {:?}",
validator_types[wasmparser_id]
);
let old_entry = self.wasmparser_to_wasmtime.insert(wasmparser_id, interned);
debug_assert_eq!(
old_entry, None,
"should not have already inserted {wasmparser_id:?}"
);
}
self.defining_rec_group = Some(RecGroupStart {
rec_group_index: self.types.next_rec_group(),
start: self.types.next_ty(),
end: ModuleInternedTypeIndex::new(self.types.len_types() + len),
});
}
/// Finish defining a recursion group.
fn end_rec_group(
&mut self,
rec_group_id: wasmparser::types::RecGroupId,
) -> ModuleInternedRecGroupIndex {
let RecGroupStart {
rec_group_index,
start,
end,
} = self
.defining_rec_group
.take()
.expect("should be defining a rec group");
log::trace!("Ending rec group {start:?}..{end:?}");
debug_assert!(start.index() < self.types.len_types());
debug_assert_eq!(
end,
self.types.next_ty(),
"should have defined the number of types declared in `start_rec_group`"
);
let idx = self.types.push_rec_group(start..end);
debug_assert_eq!(idx, rec_group_index);
self.already_seen.insert(rec_group_id, rec_group_index);
rec_group_index
}
/// Intern a type into this builder and get its Wasmtime index.
///
/// This will intern not only the single given type, but the type's entire
/// rec group. This helper method is provided as a convenience so that
/// callers don't have to get the type's rec group, intern the rec group,
/// and then look up the Wasmtime index for the original type themselves.
pub fn intern_type(
&mut self,
validator_types: wasmparser::types::TypesRef<'_>,
id: wasmparser::types::CoreTypeId,
) -> WasmResult<ModuleInternedTypeIndex> {
assert!(self.defining_rec_group.is_none());
assert_eq!(validator_types.id(), self.validator_id);
let rec_group_id = validator_types.rec_group_id_of(id);
debug_assert!(validator_types
.rec_group_elements(rec_group_id)
.any(|e| e == id));
let interned_rec_group = self.intern_rec_group(validator_types, rec_group_id)?;
let interned_type = self.wasmparser_to_wasmtime[&id];
debug_assert!(self
.rec_group_elements(interned_rec_group)
.any(|e| e == interned_type));
Ok(interned_type)
}
/// Define a new Wasm type while we are defining a rec group.
fn wasm_sub_type_in_rec_group(
&mut self,
id: wasmparser::types::CoreTypeId,
ty: WasmSubType,
) -> ModuleInternedTypeIndex {
assert!(
self.defining_rec_group.is_some(),
"must be defining a rec group to define new types"
);
let module_interned_index = self.types.push(ty);
debug_assert_eq!(
self.wasmparser_to_wasmtime.get(&id),
Some(&module_interned_index),
"should have reserved the right module-interned index for this wasmparser type already"
);
module_interned_index
}
/// Returns the result [`ModuleTypes`] of this builder.
pub fn finish(self) -> ModuleTypes {
self.types
}
/// Get the elements within an already-defined rec group.
pub fn rec_group_elements(
&self,
rec_group: ModuleInternedRecGroupIndex,
) -> impl ExactSizeIterator<Item = ModuleInternedTypeIndex> {
self.types.rec_group_elements(rec_group)
}
/// Returns an iterator over all the unique wasm types defined thus far
/// within this builder.
pub fn wasm_types(&self) -> impl Iterator<Item = (ModuleInternedTypeIndex, &WasmSubType)> {
self.types.wasm_types()
}
/// Get an iterator over all function types and their associated trampoline
/// type.
pub fn trampoline_types(
&self,
) -> impl Iterator<Item = (ModuleInternedTypeIndex, ModuleInternedTypeIndex)> + '_ {
self.types.trampoline_types()
}
/// Get the associated trampoline type for the given function type.
pub fn trampoline_type(&self, ty: ModuleInternedTypeIndex) -> ModuleInternedTypeIndex {
self.types.trampoline_type(ty)
}
/// Get and unwrap a [`WasmStructType`] for the given struct index.
///
/// # Panics
///
/// Panics if the unwrapped type is not a struct.
///
/// # Errors
///
/// For now, fails with an unsupported error if the type is shared.
pub fn unwrap_struct(&self, ty: ModuleInternedTypeIndex) -> WasmResult<&WasmStructType> {
let composite_type = &self.types[ty].composite_type;
if composite_type.shared {
return Err(wasm_unsupported!("shared structs are not yet implemented"));
}
match &composite_type.inner {
WasmCompositeInnerType::Struct(s) => Ok(s),
_ => unreachable!(),
}
}
/// Get and unwrap a [`WasmArrayType`] for the given array index.
///
/// # Panics
///
/// Panics if the unwrapped type is not an array.
///
/// # Errors
///
/// For now, fails with an unsupported error if the type is shared.
pub fn unwrap_array(&self, interned_ty: ModuleInternedTypeIndex) -> WasmResult<&WasmArrayType> {
let composite_type = &self.types[interned_ty].composite_type;
if composite_type.shared {
return Err(wasm_unsupported!("shared arrays are not yet implemented"));
}
match &composite_type.inner {
WasmCompositeInnerType::Array(a) => Ok(a),
_ => unreachable!(),
}
}
}
// Forward the indexing impl to the internal `ModuleTypes`
impl<T> Index<T> for ModuleTypesBuilder
where
ModuleTypes: Index<T>,
{
type Output = <ModuleTypes as Index<T>>::Output;
fn index(&self, sig: T) -> &Self::Output {
&self.types[sig]
}
}
/// A convert from `wasmparser` types to Wasmtime types.
pub struct WasmparserTypeConverter<'a, F> {
types: &'a ModuleTypesBuilder,
lookup_type_idx: F,
rec_group_context: Option<(
wasmparser::types::TypesRef<'a>,
wasmparser::types::RecGroupId,
)>,
}
impl<'a, F> WasmparserTypeConverter<'a, F> {
/// Construct a new type converter from `wasmparser` types to Wasmtime types.
pub fn new(types: &'a ModuleTypesBuilder, lookup_type_idx: F) -> Self {
Self {
types,
lookup_type_idx,
rec_group_context: None,
}
}
/// Configure this converter to be within the context of defining the
/// current rec group.
pub fn with_rec_group(
&mut self,
wasmparser_types: wasmparser::types::TypesRef<'a>,
rec_group: wasmparser::types::RecGroupId,
) -> &Self {
self.rec_group_context = Some((wasmparser_types, rec_group));
self
}
}
impl<F> TypeConvert for WasmparserTypeConverter<'_, F>
where
F: Fn(TypeIndex) -> ModuleInternedTypeIndex,
{
fn lookup_heap_type(&self, index: UnpackedIndex) -> WasmHeapType {
match index {
UnpackedIndex::Id(id) => {
let interned = self.types.wasmparser_to_wasmtime[&id];
let index = EngineOrModuleTypeIndex::Module(interned);
// If this is a forward reference to a type in this type's rec
// group that we haven't converted yet, then we won't have an
// entry in `wasm_types` yet. In this case, fallback to a
// different means of determining whether this is a concrete
// array vs struct vs func reference. In this case, we can use
// the validator's type context.
if let Some(ty) = self.types.types.get(interned) {
assert!(!ty.composite_type.shared);
match &ty.composite_type.inner {
WasmCompositeInnerType::Array(_) => WasmHeapType::ConcreteArray(index),
WasmCompositeInnerType::Func(_) => WasmHeapType::ConcreteFunc(index),
WasmCompositeInnerType::Struct(_) => WasmHeapType::ConcreteStruct(index),
}
} else if let Some((wasmparser_types, _)) = self.rec_group_context.as_ref() {
let wasmparser_ty = &wasmparser_types[id].composite_type;
assert!(!wasmparser_ty.shared);
match &wasmparser_ty.inner {
wasmparser::CompositeInnerType::Array(_) => {
WasmHeapType::ConcreteArray(index)
}
wasmparser::CompositeInnerType::Func(_) => {
WasmHeapType::ConcreteFunc(index)
}
wasmparser::CompositeInnerType::Struct(_) => {
WasmHeapType::ConcreteStruct(index)
}
wasmparser::CompositeInnerType::Cont(_) => {
panic!("unimplemented continuation types")
}
}
} else {
panic!("forward reference to type outside of rec group?")
}
}
UnpackedIndex::Module(module_index) => {
let module_index = TypeIndex::from_u32(module_index);
let interned = (self.lookup_type_idx)(module_index);
let index = EngineOrModuleTypeIndex::Module(interned);
// See comment above about `wasm_types` maybe not having the
// converted sub type yet. However in this case we don't have a
// `wasmparser::types::CoreTypeId` on hand, so we have to
// indirectly get one by looking it up inside the current rec
// group.
if let Some(ty) = self.types.types.get(interned) {
assert!(!ty.composite_type.shared);
match &ty.composite_type.inner {
WasmCompositeInnerType::Array(_) => WasmHeapType::ConcreteArray(index),
WasmCompositeInnerType::Func(_) => WasmHeapType::ConcreteFunc(index),
WasmCompositeInnerType::Struct(_) => WasmHeapType::ConcreteStruct(index),
}
} else if let Some((parser_types, rec_group)) = self.rec_group_context.as_ref() {
let rec_group_index = interned.index() - self.types.types.len_types();
let id = parser_types
.rec_group_elements(*rec_group)
.nth(rec_group_index)
.unwrap();
let wasmparser_ty = &parser_types[id].composite_type;
assert!(!wasmparser_ty.shared);
match &wasmparser_ty.inner {
wasmparser::CompositeInnerType::Array(_) => {
WasmHeapType::ConcreteArray(index)
}
wasmparser::CompositeInnerType::Func(_) => {
WasmHeapType::ConcreteFunc(index)
}
wasmparser::CompositeInnerType::Struct(_) => {
WasmHeapType::ConcreteStruct(index)
}
wasmparser::CompositeInnerType::Cont(_) => {
panic!("unimplemented continuation types")
}
}
} else {
panic!("forward reference to type outside of rec group?")
}
}
UnpackedIndex::RecGroup(_) => unreachable!(),
}
}
fn lookup_type_index(&self, index: wasmparser::UnpackedIndex) -> EngineOrModuleTypeIndex {
match index {
UnpackedIndex::Id(id) => {
let interned = self.types.wasmparser_to_wasmtime[&id];
EngineOrModuleTypeIndex::Module(interned)
}
UnpackedIndex::Module(module_index) => {
let module_index = TypeIndex::from_u32(module_index);
let interned = (self.lookup_type_idx)(module_index);
EngineOrModuleTypeIndex::Module(interned)
}
UnpackedIndex::RecGroup(_) => unreachable!(),
}
}
}