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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
use crate::runtime::vm::TableElement;
use crate::store::{AutoAssertNoGc, StoreOpaque};
use crate::{
prelude::*, AnyRef, ArrayRef, AsContext, AsContextMut, ExternRef, Func, HeapType, RefType,
Rooted, RootedGcRefImpl, StructRef, ValType, V128,
};
use core::ptr;
pub use crate::runtime::vm::ValRaw;
/// Possible runtime values that a WebAssembly module can either consume or
/// produce.
///
/// Note that we inline the `enum Ref { ... }` variants into `enum Val { ... }`
/// here as a size optimization.
#[derive(Debug, Clone, Copy)]
pub enum Val {
// NB: the ordering here is intended to match the ordering in
// `ValType` to improve codegen when learning the type of a value.
//
/// A 32-bit integer.
I32(i32),
/// A 64-bit integer.
I64(i64),
/// A 32-bit float.
///
/// Note that the raw bits of the float are stored here, and you can use
/// `f32::from_bits` to create an `f32` value.
F32(u32),
/// A 64-bit float.
///
/// Note that the raw bits of the float are stored here, and you can use
/// `f64::from_bits` to create an `f64` value.
F64(u64),
/// A 128-bit number.
V128(V128),
/// A function reference.
FuncRef(Option<Func>),
/// An external reference.
ExternRef(Option<Rooted<ExternRef>>),
/// An internal reference.
AnyRef(Option<Rooted<AnyRef>>),
}
macro_rules! accessors {
($bind:ident $(($variant:ident($ty:ty) $get:ident $unwrap:ident $cvt:expr))*) => ($(
/// Attempt to access the underlying value of this `Val`, returning
/// `None` if it is not the correct type.
#[inline]
pub fn $get(&self) -> Option<$ty> {
if let Val::$variant($bind) = self {
Some($cvt)
} else {
None
}
}
/// Returns the underlying value of this `Val`, panicking if it's the
/// wrong type.
///
/// # Panics
///
/// Panics if `self` is not of the right type.
#[inline]
pub fn $unwrap(&self) -> $ty {
self.$get().expect(concat!("expected ", stringify!($ty)))
}
)*)
}
impl Val {
/// Returns the null reference for the given heap type.
#[inline]
pub fn null_ref(heap_type: &HeapType) -> Val {
Ref::null(&heap_type).into()
}
/// Returns the null function reference value.
///
/// The return value has type `(ref null nofunc)` aka `nullfuncref` and is a
/// subtype of all function references.
#[inline]
pub const fn null_func_ref() -> Val {
Val::FuncRef(None)
}
/// Returns the null function reference value.
///
/// The return value has type `(ref null extern)` aka `nullexternref` and is
/// a subtype of all external references.
#[inline]
pub const fn null_extern_ref() -> Val {
Val::ExternRef(None)
}
/// Returns the null function reference value.
///
/// The return value has type `(ref null any)` aka `nullref` and is a
/// subtype of all internal references.
#[inline]
pub const fn null_any_ref() -> Val {
Val::AnyRef(None)
}
/// Returns the corresponding [`ValType`] for this `Val`.
///
/// # Errors
///
/// Returns an error if this value is a GC reference that has since been
/// unrooted.
///
/// # Panics
///
/// Panics if this value is associated with a different store.
#[inline]
pub fn ty(&self, store: impl AsContext) -> Result<ValType> {
self.load_ty(&store.as_context().0)
}
#[inline]
pub(crate) fn load_ty(&self, store: &StoreOpaque) -> Result<ValType> {
Ok(match self {
Val::I32(_) => ValType::I32,
Val::I64(_) => ValType::I64,
Val::F32(_) => ValType::F32,
Val::F64(_) => ValType::F64,
Val::V128(_) => ValType::V128,
Val::ExternRef(Some(_)) => ValType::EXTERNREF,
Val::ExternRef(None) => ValType::NULLFUNCREF,
Val::FuncRef(None) => ValType::NULLFUNCREF,
Val::FuncRef(Some(f)) => ValType::Ref(RefType::new(
false,
HeapType::ConcreteFunc(f.load_ty(store)),
)),
Val::AnyRef(None) => ValType::NULLREF,
Val::AnyRef(Some(a)) => ValType::Ref(RefType::new(false, a._ty(store)?)),
})
}
/// Does this value match the given type?
///
/// Returns an error is an underlying `Rooted` has been unrooted.
///
/// # Panics
///
/// Panics if this value is not associated with the given store.
pub fn matches_ty(&self, store: impl AsContext, ty: &ValType) -> Result<bool> {
self._matches_ty(&store.as_context().0, ty)
}
pub(crate) fn _matches_ty(&self, store: &StoreOpaque, ty: &ValType) -> Result<bool> {
assert!(self.comes_from_same_store(store));
assert!(ty.comes_from_same_engine(store.engine()));
Ok(match (self, ty) {
(Val::I32(_), ValType::I32)
| (Val::I64(_), ValType::I64)
| (Val::F32(_), ValType::F32)
| (Val::F64(_), ValType::F64)
| (Val::V128(_), ValType::V128) => true,
(Val::FuncRef(f), ValType::Ref(ref_ty)) => Ref::from(*f)._matches_ty(store, ref_ty)?,
(Val::ExternRef(e), ValType::Ref(ref_ty)) => {
Ref::from(*e)._matches_ty(store, ref_ty)?
}
(Val::AnyRef(a), ValType::Ref(ref_ty)) => Ref::from(*a)._matches_ty(store, ref_ty)?,
(Val::I32(_), _)
| (Val::I64(_), _)
| (Val::F32(_), _)
| (Val::F64(_), _)
| (Val::V128(_), _)
| (Val::FuncRef(_), _)
| (Val::ExternRef(_), _)
| (Val::AnyRef(_), _) => false,
})
}
pub(crate) fn ensure_matches_ty(&self, store: &StoreOpaque, ty: &ValType) -> Result<()> {
if !self.comes_from_same_store(store) {
bail!("value used with wrong store")
}
if !ty.comes_from_same_engine(store.engine()) {
bail!("type used with wrong engine")
}
if self._matches_ty(store, ty)? {
Ok(())
} else {
let actual_ty = self.load_ty(store)?;
bail!("type mismatch: expected {ty}, found {actual_ty}")
}
}
/// Convenience method to convert this [`Val`] into a [`ValRaw`].
///
/// Returns an error if this value is a GC reference and the GC reference
/// has been unrooted.
///
/// # Unsafety
///
/// This method is unsafe for the reasons that [`ExternRef::to_raw`] and
/// [`Func::to_raw`] are unsafe.
pub unsafe fn to_raw(&self, store: impl AsContextMut) -> Result<ValRaw> {
match self {
Val::I32(i) => Ok(ValRaw::i32(*i)),
Val::I64(i) => Ok(ValRaw::i64(*i)),
Val::F32(u) => Ok(ValRaw::f32(*u)),
Val::F64(u) => Ok(ValRaw::f64(*u)),
Val::V128(b) => Ok(ValRaw::v128(b.as_u128())),
Val::ExternRef(e) => Ok(ValRaw::externref(match e {
None => 0,
Some(e) => e.to_raw(store)?,
})),
Val::AnyRef(e) => Ok(ValRaw::anyref(match e {
None => 0,
Some(e) => e.to_raw(store)?,
})),
Val::FuncRef(f) => Ok(ValRaw::funcref(match f {
Some(f) => f.to_raw(store),
None => ptr::null_mut(),
})),
}
}
/// Convenience method to convert a [`ValRaw`] into a [`Val`].
///
/// # Unsafety
///
/// This method is unsafe for the reasons that [`ExternRef::from_raw`] and
/// [`Func::from_raw`] are unsafe. Additionally there's no guarantee
/// otherwise that `raw` should have the type `ty` specified.
pub unsafe fn from_raw(store: impl AsContextMut, raw: ValRaw, ty: ValType) -> Val {
match ty {
ValType::I32 => Val::I32(raw.get_i32()),
ValType::I64 => Val::I64(raw.get_i64()),
ValType::F32 => Val::F32(raw.get_f32()),
ValType::F64 => Val::F64(raw.get_f64()),
ValType::V128 => Val::V128(raw.get_v128().into()),
ValType::Ref(ref_ty) => {
let ref_ = match ref_ty.heap_type() {
HeapType::Func | HeapType::ConcreteFunc(_) => {
Func::from_raw(store, raw.get_funcref()).into()
}
HeapType::NoFunc => Ref::Func(None),
HeapType::Extern => ExternRef::from_raw(store, raw.get_externref()).into(),
HeapType::NoExtern => Ref::Extern(None),
HeapType::Any
| HeapType::Eq
| HeapType::I31
| HeapType::Array
| HeapType::ConcreteArray(_)
| HeapType::Struct
| HeapType::ConcreteStruct(_) => {
AnyRef::from_raw(store, raw.get_anyref()).into()
}
HeapType::None => Ref::Any(None),
};
assert!(
ref_ty.is_nullable() || !ref_.is_null(),
"if the type is not nullable, we shouldn't get null; got \
type = {ref_ty}, ref = {ref_:?}"
);
ref_.into()
}
}
}
accessors! {
e
(I32(i32) i32 unwrap_i32 *e)
(I64(i64) i64 unwrap_i64 *e)
(F32(f32) f32 unwrap_f32 f32::from_bits(*e))
(F64(f64) f64 unwrap_f64 f64::from_bits(*e))
(FuncRef(Option<&Func>) func_ref unwrap_func_ref e.as_ref())
(ExternRef(Option<&Rooted<ExternRef>>) extern_ref unwrap_extern_ref e.as_ref())
(AnyRef(Option<&Rooted<AnyRef>>) any_ref unwrap_any_ref e.as_ref())
(V128(V128) v128 unwrap_v128 *e)
}
/// Get this value's underlying reference, if any.
#[inline]
pub fn ref_(self) -> Option<Ref> {
match self {
Val::FuncRef(f) => Some(Ref::Func(f)),
Val::ExternRef(e) => Some(Ref::Extern(e)),
Val::AnyRef(a) => Some(Ref::Any(a)),
Val::I32(_) | Val::I64(_) | Val::F32(_) | Val::F64(_) | Val::V128(_) => None,
}
}
/// Attempt to access the underlying `externref` value of this `Val`.
///
/// If this is not an `externref`, then `None` is returned.
///
/// If this is a null `externref`, then `Some(None)` is returned.
///
/// If this is a non-null `externref`, then `Some(Some(..))` is returned.
#[inline]
pub fn externref(&self) -> Option<Option<&Rooted<ExternRef>>> {
match self {
Val::ExternRef(None) => Some(None),
Val::ExternRef(Some(e)) => Some(Some(e)),
_ => None,
}
}
/// Returns the underlying `externref` value of this `Val`, panicking if it's the
/// wrong type.
///
/// If this is a null `externref`, then `None` is returned.
///
/// If this is a non-null `externref`, then `Some(..)` is returned.
///
/// # Panics
///
/// Panics if `self` is not a (nullable) `externref`.
#[inline]
pub fn unwrap_externref(&self) -> Option<&Rooted<ExternRef>> {
self.externref().expect("expected externref")
}
/// Attempt to access the underlying `anyref` value of this `Val`.
///
/// If this is not an `anyref`, then `None` is returned.
///
/// If this is a null `anyref`, then `Some(None)` is returned.
///
/// If this is a non-null `anyref`, then `Some(Some(..))` is returned.
#[inline]
pub fn anyref(&self) -> Option<Option<&Rooted<AnyRef>>> {
match self {
Val::AnyRef(None) => Some(None),
Val::AnyRef(Some(e)) => Some(Some(e)),
_ => None,
}
}
/// Returns the underlying `anyref` value of this `Val`, panicking if it's the
/// wrong type.
///
/// If this is a null `anyref`, then `None` is returned.
///
/// If this is a non-null `anyref`, then `Some(..)` is returned.
///
/// # Panics
///
/// Panics if `self` is not a (nullable) `anyref`.
#[inline]
pub fn unwrap_anyref(&self) -> Option<&Rooted<AnyRef>> {
self.anyref().expect("expected anyref")
}
/// Attempt to access the underlying `funcref` value of this `Val`.
///
/// If this is not an `funcref`, then `None` is returned.
///
/// If this is a null `funcref`, then `Some(None)` is returned.
///
/// If this is a non-null `funcref`, then `Some(Some(..))` is returned.
#[inline]
pub fn funcref(&self) -> Option<Option<&Func>> {
match self {
Val::FuncRef(None) => Some(None),
Val::FuncRef(Some(f)) => Some(Some(f)),
_ => None,
}
}
/// Returns the underlying `funcref` value of this `Val`, panicking if it's the
/// wrong type.
///
/// If this is a null `funcref`, then `None` is returned.
///
/// If this is a non-null `funcref`, then `Some(..)` is returned.
///
/// # Panics
///
/// Panics if `self` is not a (nullable) `funcref`.
#[inline]
pub fn unwrap_funcref(&self) -> Option<&Func> {
self.funcref().expect("expected funcref")
}
#[inline]
pub(crate) fn comes_from_same_store(&self, store: &StoreOpaque) -> bool {
match self {
Val::FuncRef(Some(f)) => f.comes_from_same_store(store),
Val::FuncRef(None) => true,
Val::ExternRef(Some(x)) => x.comes_from_same_store(store),
Val::ExternRef(None) => true,
Val::AnyRef(Some(a)) => a.comes_from_same_store(store),
Val::AnyRef(None) => true,
// Integers, floats, and vectors have no association with any
// particular store, so they're always considered as "yes I came
// from that store",
Val::I32(_) | Val::I64(_) | Val::F32(_) | Val::F64(_) | Val::V128(_) => true,
}
}
}
impl From<i32> for Val {
#[inline]
fn from(val: i32) -> Val {
Val::I32(val)
}
}
impl From<i64> for Val {
#[inline]
fn from(val: i64) -> Val {
Val::I64(val)
}
}
impl From<f32> for Val {
#[inline]
fn from(val: f32) -> Val {
Val::F32(val.to_bits())
}
}
impl From<f64> for Val {
#[inline]
fn from(val: f64) -> Val {
Val::F64(val.to_bits())
}
}
impl From<Ref> for Val {
#[inline]
fn from(val: Ref) -> Val {
match val {
Ref::Extern(e) => Val::ExternRef(e),
Ref::Func(f) => Val::FuncRef(f),
Ref::Any(a) => Val::AnyRef(a),
}
}
}
impl From<Rooted<ExternRef>> for Val {
#[inline]
fn from(val: Rooted<ExternRef>) -> Val {
Val::ExternRef(Some(val))
}
}
impl From<Option<Rooted<ExternRef>>> for Val {
#[inline]
fn from(val: Option<Rooted<ExternRef>>) -> Val {
Val::ExternRef(val)
}
}
impl From<Rooted<AnyRef>> for Val {
#[inline]
fn from(val: Rooted<AnyRef>) -> Val {
Val::AnyRef(Some(val))
}
}
impl From<Option<Rooted<AnyRef>>> for Val {
#[inline]
fn from(val: Option<Rooted<AnyRef>>) -> Val {
Val::AnyRef(val)
}
}
impl From<Rooted<StructRef>> for Val {
#[inline]
fn from(val: Rooted<StructRef>) -> Val {
Val::AnyRef(Some(val.into()))
}
}
impl From<Option<Rooted<StructRef>>> for Val {
#[inline]
fn from(val: Option<Rooted<StructRef>>) -> Val {
Val::AnyRef(val.map(Into::into))
}
}
impl From<Rooted<ArrayRef>> for Val {
#[inline]
fn from(val: Rooted<ArrayRef>) -> Val {
Val::AnyRef(Some(val.into()))
}
}
impl From<Option<Rooted<ArrayRef>>> for Val {
#[inline]
fn from(val: Option<Rooted<ArrayRef>>) -> Val {
Val::AnyRef(val.map(Into::into))
}
}
impl From<Func> for Val {
#[inline]
fn from(val: Func) -> Val {
Val::FuncRef(Some(val))
}
}
impl From<Option<Func>> for Val {
#[inline]
fn from(val: Option<Func>) -> Val {
Val::FuncRef(val)
}
}
impl From<u128> for Val {
#[inline]
fn from(val: u128) -> Val {
Val::V128(val.into())
}
}
impl From<V128> for Val {
#[inline]
fn from(val: V128) -> Val {
Val::V128(val)
}
}
/// A reference.
///
/// References come in three broad flavors:
///
/// 1. Function references. These are references to a function that can be
/// invoked.
///
/// 2. External references. These are references to data that is external
/// and opaque to the Wasm guest, provided by the host.
///
/// 3. Internal references. These are references to allocations inside the
/// Wasm's heap, such as structs and arrays. These are part of the GC
/// proposal, and not yet implemented in Wasmtime.
///
/// At the Wasm level, there are nullable and non-nullable variants of each type
/// of reference. Both variants are represented with `Ref` at the Wasmtime API
/// level. For example, values of both `(ref extern)` and `(ref null extern)`
/// types will be represented as `Ref::Extern(Option<ExternRef>)` in the
/// Wasmtime API. Nullable references are represented as `Option<Ref>` where
/// null references are represented as `None`. Wasm can construct null
/// references via the `ref.null <heap-type>` instruction.
///
/// References are non-forgable: Wasm cannot create invalid references, for
/// example, by claiming that the integer `0xbad1bad2` is actually a reference.
#[derive(Debug, Clone)]
pub enum Ref {
// NB: We have a variant for each of the type hierarchies defined in Wasm,
// and push the `Option` that provides nullability into each variant. This
// allows us to get the most-precise type of any reference value, whether it
// is null or not, without any additional metadata.
//
// Consider if we instead had the nullability inside `Val::Ref` and each of
// the `Ref` variants did not have an `Option`:
//
// enum Val {
// Ref(Option<Ref>),
// // Etc...
// }
// enum Ref {
// Func(Func),
// External(ExternRef),
// // Etc...
// }
//
// In this scenario, what type would we return from `Val::ty` for
// `Val::Ref(None)`? Because Wasm has multiple separate type hierarchies,
// there is no single common bottom type for all the different kinds of
// references. So in this scenario, `Val::Ref(None)` doesn't have enough
// information to reconstruct the value's type. That's a problem for us
// because we need to get a value's type at various times all over the code
// base.
//
/// A first-class reference to a WebAssembly function.
///
/// The host, or the Wasm guest, can invoke this function.
///
/// The host can create function references via [`Func::new`] or
/// [`Func::wrap`].
///
/// The Wasm guest can create non-null function references via the
/// `ref.func` instruction, or null references via the `ref.null func`
/// instruction.
Func(Option<Func>),
/// A reference to an value outside of the Wasm heap.
///
/// These references are opaque to the Wasm itself. Wasm can't create
/// non-null external references, nor do anything with them accept pass them
/// around as function arguments and returns and place them into globals and
/// tables.
///
/// Wasm can create null external references via the `ref.null extern`
/// instruction.
Extern(Option<Rooted<ExternRef>>),
/// An internal reference.
///
/// The `AnyRef` type represents WebAssembly `anyref` values. These can be
/// references to `struct`s and `array`s or inline/unboxed 31-bit
/// integers.
///
/// Unlike `externref`, Wasm guests can directly allocate `anyref`s, and
/// does not need to rely on the host to do that.
Any(Option<Rooted<AnyRef>>),
}
impl From<Func> for Ref {
#[inline]
fn from(f: Func) -> Ref {
Ref::Func(Some(f))
}
}
impl From<Option<Func>> for Ref {
#[inline]
fn from(f: Option<Func>) -> Ref {
Ref::Func(f)
}
}
impl From<Rooted<ExternRef>> for Ref {
#[inline]
fn from(e: Rooted<ExternRef>) -> Ref {
Ref::Extern(Some(e))
}
}
impl From<Option<Rooted<ExternRef>>> for Ref {
#[inline]
fn from(e: Option<Rooted<ExternRef>>) -> Ref {
Ref::Extern(e)
}
}
impl From<Rooted<AnyRef>> for Ref {
#[inline]
fn from(e: Rooted<AnyRef>) -> Ref {
Ref::Any(Some(e))
}
}
impl From<Option<Rooted<AnyRef>>> for Ref {
#[inline]
fn from(e: Option<Rooted<AnyRef>>) -> Ref {
Ref::Any(e)
}
}
impl From<Rooted<StructRef>> for Ref {
#[inline]
fn from(e: Rooted<StructRef>) -> Ref {
Ref::Any(Some(e.into()))
}
}
impl From<Option<Rooted<StructRef>>> for Ref {
#[inline]
fn from(e: Option<Rooted<StructRef>>) -> Ref {
Ref::Any(e.map(Into::into))
}
}
impl From<Rooted<ArrayRef>> for Ref {
#[inline]
fn from(e: Rooted<ArrayRef>) -> Ref {
Ref::Any(Some(e.into()))
}
}
impl From<Option<Rooted<ArrayRef>>> for Ref {
#[inline]
fn from(e: Option<Rooted<ArrayRef>>) -> Ref {
Ref::Any(e.map(Into::into))
}
}
impl Ref {
/// Create a null reference to the given heap type.
#[inline]
pub fn null(heap_type: &HeapType) -> Self {
match heap_type.top() {
HeapType::Any => Ref::Any(None),
HeapType::Extern => Ref::Extern(None),
HeapType::Func => Ref::Func(None),
ty => unreachable!("not a heap type: {ty:?}"),
}
}
/// Is this a null reference?
#[inline]
pub fn is_null(&self) -> bool {
match self {
Ref::Any(None) | Ref::Extern(None) | Ref::Func(None) => true,
Ref::Any(Some(_)) | Ref::Extern(Some(_)) | Ref::Func(Some(_)) => false,
}
}
/// Is this a non-null reference?
#[inline]
pub fn is_non_null(&self) -> bool {
!self.is_null()
}
/// Is this an `extern` reference?
#[inline]
pub fn is_extern(&self) -> bool {
matches!(self, Ref::Extern(_))
}
/// Get the underlying `extern` reference, if any.
///
/// Returns `None` if this `Ref` is not an `extern` reference, eg it is a
/// `func` reference.
///
/// Returns `Some(None)` if this `Ref` is a null `extern` reference.
///
/// Returns `Some(Some(_))` if this `Ref` is a non-null `extern` reference.
#[inline]
pub fn as_extern(&self) -> Option<Option<&Rooted<ExternRef>>> {
match self {
Ref::Extern(e) => Some(e.as_ref()),
_ => None,
}
}
/// Get the underlying `extern` reference, panicking if this is a different
/// kind of reference.
///
/// Returns `None` if this `Ref` is a null `extern` reference.
///
/// Returns `Some(_)` if this `Ref` is a non-null `extern` reference.
#[inline]
pub fn unwrap_extern(&self) -> Option<&Rooted<ExternRef>> {
self.as_extern()
.expect("Ref::unwrap_extern on non-extern reference")
}
/// Is this an `any` reference?
#[inline]
pub fn is_any(&self) -> bool {
matches!(self, Ref::Any(_))
}
/// Get the underlying `any` reference, if any.
///
/// Returns `None` if this `Ref` is not an `any` reference, eg it is a
/// `func` reference.
///
/// Returns `Some(None)` if this `Ref` is a null `any` reference.
///
/// Returns `Some(Some(_))` if this `Ref` is a non-null `any` reference.
#[inline]
pub fn as_any(&self) -> Option<Option<&Rooted<AnyRef>>> {
match self {
Ref::Any(e) => Some(e.as_ref()),
_ => None,
}
}
/// Get the underlying `any` reference, panicking if this is a different
/// kind of reference.
///
/// Returns `None` if this `Ref` is a null `any` reference.
///
/// Returns `Some(_)` if this `Ref` is a non-null `any` reference.
#[inline]
pub fn unwrap_any(&self) -> Option<&Rooted<AnyRef>> {
self.as_any().expect("Ref::unwrap_any on non-any reference")
}
/// Is this a `func` reference?
#[inline]
pub fn is_func(&self) -> bool {
matches!(self, Ref::Func(_))
}
/// Get the underlying `func` reference, if any.
///
/// Returns `None` if this `Ref` is not an `func` reference, eg it is an
/// `extern` reference.
///
/// Returns `Some(None)` if this `Ref` is a null `func` reference.
///
/// Returns `Some(Some(_))` if this `Ref` is a non-null `func` reference.
#[inline]
pub fn as_func(&self) -> Option<Option<&Func>> {
match self {
Ref::Func(f) => Some(f.as_ref()),
_ => None,
}
}
/// Get the underlying `func` reference, panicking if this is a different
/// kind of reference.
///
/// Returns `None` if this `Ref` is a null `func` reference.
///
/// Returns `Some(_)` if this `Ref` is a non-null `func` reference.
#[inline]
pub fn unwrap_func(&self) -> Option<&Func> {
self.as_func()
.expect("Ref::unwrap_func on non-func reference")
}
/// Get the type of this reference.
///
/// # Errors
///
/// Return an error if this reference has been unrooted.
///
/// # Panics
///
/// Panics if this reference is associated with a different store.
pub fn ty(&self, store: impl AsContext) -> Result<RefType> {
self.load_ty(&store.as_context().0)
}
pub(crate) fn load_ty(&self, store: &StoreOpaque) -> Result<RefType> {
assert!(self.comes_from_same_store(store));
Ok(RefType::new(
self.is_null(),
// NB: We choose the most-specific heap type we can here and let
// subtyping do its thing if callers are matching against a
// `HeapType::Func`.
match self {
Ref::Extern(None) => HeapType::NoExtern,
Ref::Extern(Some(_)) => HeapType::Extern,
Ref::Func(None) => HeapType::NoFunc,
Ref::Func(Some(f)) => HeapType::ConcreteFunc(f.load_ty(store)),
Ref::Any(None) => HeapType::None,
Ref::Any(Some(a)) => a._ty(store)?,
},
))
}
/// Does this reference value match the given type?
///
/// Returns an error if the underlying `Rooted` has been unrooted.
///
/// # Panics
///
/// Panics if this reference is not associated with the given store.
pub fn matches_ty(&self, store: impl AsContext, ty: &RefType) -> Result<bool> {
self._matches_ty(&store.as_context().0, ty)
}
pub(crate) fn _matches_ty(&self, store: &StoreOpaque, ty: &RefType) -> Result<bool> {
assert!(self.comes_from_same_store(store));
assert!(ty.comes_from_same_engine(store.engine()));
if self.is_null() && !ty.is_nullable() {
return Ok(false);
}
Ok(match (self, ty.heap_type()) {
(Ref::Extern(_), HeapType::Extern) => true,
(Ref::Extern(_), _) => false,
(Ref::Func(_), HeapType::Func) => true,
(Ref::Func(None), HeapType::NoFunc | HeapType::ConcreteFunc(_)) => true,
(Ref::Func(Some(f)), HeapType::ConcreteFunc(func_ty)) => f._matches_ty(store, func_ty),
(Ref::Func(_), _) => false,
(Ref::Any(_), HeapType::Any) => true,
(Ref::Any(Some(a)), HeapType::I31) => a._is_i31(store)?,
(Ref::Any(Some(a)), HeapType::Struct) => a._is_struct(store)?,
(Ref::Any(Some(a)), HeapType::ConcreteStruct(_ty)) => match a._as_struct(store)? {
None => false,
#[cfg_attr(not(feature = "gc"), allow(unreachable_patterns))]
Some(s) => s._matches_ty(store, _ty)?,
},
(Ref::Any(Some(_)), HeapType::Eq) => todo!("eqref"),
(Ref::Any(Some(a)), HeapType::Array) => a._is_array(store)?,
(Ref::Any(Some(a)), HeapType::ConcreteArray(_ty)) => match a._as_array(store)? {
None => false,
#[cfg_attr(not(feature = "gc"), allow(unreachable_patterns))]
Some(a) => a._matches_ty(store, _ty)?,
},
(
Ref::Any(None),
HeapType::None
| HeapType::I31
| HeapType::ConcreteStruct(_)
| HeapType::Struct
| HeapType::ConcreteArray(_)
| HeapType::Array,
) => true,
(Ref::Any(_), _) => false,
})
}
pub(crate) fn ensure_matches_ty(&self, store: &StoreOpaque, ty: &RefType) -> Result<()> {
if !self.comes_from_same_store(store) {
bail!("reference used with wrong store")
}
if !ty.comes_from_same_engine(store.engine()) {
bail!("type used with wrong engine")
}
if self._matches_ty(store, ty)? {
Ok(())
} else {
let actual_ty = self.load_ty(store)?;
bail!("type mismatch: expected {ty}, found {actual_ty}")
}
}
pub(crate) fn comes_from_same_store(&self, store: &StoreOpaque) -> bool {
match self {
Ref::Func(Some(f)) => f.comes_from_same_store(store),
Ref::Func(None) => true,
Ref::Extern(Some(x)) => x.comes_from_same_store(store),
Ref::Extern(None) => true,
Ref::Any(Some(a)) => a.comes_from_same_store(store),
Ref::Any(None) => true,
}
}
pub(crate) fn into_table_element(
self,
store: &mut StoreOpaque,
ty: &RefType,
) -> Result<TableElement> {
let mut store = AutoAssertNoGc::new(store);
self.ensure_matches_ty(&store, &ty)
.context("type mismatch: value does not match table element type")?;
match (self, ty.heap_type().top()) {
(Ref::Func(None), HeapType::Func) => {
assert!(ty.is_nullable());
Ok(TableElement::FuncRef(ptr::null_mut()))
}
(Ref::Func(Some(f)), HeapType::Func) => {
debug_assert!(
f.comes_from_same_store(&store),
"checked in `ensure_matches_ty`"
);
Ok(TableElement::FuncRef(f.vm_func_ref(&mut store).as_ptr()))
}
(Ref::Extern(e), HeapType::Extern) => match e {
None => {
assert!(ty.is_nullable());
Ok(TableElement::GcRef(None))
}
#[cfg_attr(not(feature = "gc"), allow(unreachable_patterns))]
Some(e) => {
let gc_ref = e.try_clone_gc_ref(&mut store)?;
Ok(TableElement::GcRef(Some(gc_ref)))
}
},
(Ref::Any(a), HeapType::Any) => match a {
None => {
assert!(ty.is_nullable());
Ok(TableElement::GcRef(None))
}
#[cfg_attr(not(feature = "gc"), allow(unreachable_patterns))]
Some(a) => {
let gc_ref = a.try_clone_gc_ref(&mut store)?;
Ok(TableElement::GcRef(Some(gc_ref)))
}
},
_ => unreachable!("checked that the value matches the type above"),
}
}
}
#[cfg(test)]
mod tests {
use crate::*;
#[test]
fn size_of_val() {
// Try to keep tabs on the size of `Val` and make sure we don't grow its
// size.
assert_eq!(
std::mem::size_of::<Val>(),
if cfg!(any(
target_arch = "x86_64",
target_arch = "aarch64",
target_arch = "riscv64",
target_arch = "s390x"
)) {
24
} else {
panic!("unsupported architecture")
}
);
}
#[test]
fn size_of_ref() {
// Try to keep tabs on the size of `Ref` and make sure we don't grow its
// size.
assert_eq!(std::mem::size_of::<Ref>(), 24);
}
#[test]
#[should_panic]
fn val_matches_ty_wrong_engine() {
let e1 = Engine::default();
let e2 = Engine::default();
let t1 = FuncType::new(&e1, None, None);
let t2 = FuncType::new(&e2, None, None);
let mut s1 = Store::new(&e1, ());
let f = Func::new(&mut s1, t1.clone(), |_caller, _args, _results| Ok(()));
// Should panic.
let _ = Val::FuncRef(Some(f)).matches_ty(
&s1,
&ValType::Ref(RefType::new(true, HeapType::ConcreteFunc(t2))),
);
}
#[test]
#[should_panic]
fn ref_matches_ty_wrong_engine() {
let e1 = Engine::default();
let e2 = Engine::default();
let t1 = FuncType::new(&e1, None, None);
let t2 = FuncType::new(&e2, None, None);
let mut s1 = Store::new(&e1, ());
let f = Func::new(&mut s1, t1.clone(), |_caller, _args, _results| Ok(()));
// Should panic.
let _ = Ref::Func(Some(f)).matches_ty(&s1, &RefType::new(true, HeapType::ConcreteFunc(t2)));
}
}