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 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173
//! Runtime support for the `wasm-bindgen` tool //! //! This crate contains the runtime support necessary for `wasm-bindgen` the //! attribute and tool. Crates pull in the `#[wasm_bindgen]` attribute through //! this crate and this crate also provides JS bindings through the `JsValue` //! interface. #![no_std] #![allow(coherence_leak_check)] #![doc(html_root_url = "https://docs.rs/wasm-bindgen/0.2")] #![cfg_attr(feature = "nightly", feature(unsize))] use core::fmt; use core::marker; use core::mem; use core::ops::{Deref, DerefMut}; use crate::convert::{FromWasmAbi, WasmOptionalF64, WasmSlice}; macro_rules! if_std { ($($i:item)*) => ($( #[cfg(feature = "std")] $i )*) } macro_rules! externs { ($(#[$attr:meta])* extern "C" { $(fn $name:ident($($args:tt)*) -> $ret:ty;)* }) => ( #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] $(#[$attr])* extern "C" { $(fn $name($($args)*) -> $ret;)* } $( #[cfg(not(all(target_arch = "wasm32", not(target_os = "emscripten"))))] #[allow(unused_variables)] unsafe extern fn $name($($args)*) -> $ret { panic!("function not implemented on non-wasm32 targets") } )* ) } /// A module which is typically glob imported from: /// /// ``` /// use wasm_bindgen::prelude::*; /// ``` pub mod prelude { pub use crate::JsValue; pub use crate::UnwrapThrowExt; #[doc(hidden)] pub use wasm_bindgen_macro::__wasm_bindgen_class_marker; pub use wasm_bindgen_macro::wasm_bindgen; if_std! { pub use crate::closure::Closure; } } pub mod convert; pub mod describe; mod cast; pub use crate::cast::JsCast; if_std! { extern crate std; use std::prelude::v1::*; pub mod closure; mod externref; mod cache; pub use cache::intern::{intern, unintern}; } /// Representation of an object owned by JS. /// /// A `JsValue` doesn't actually live in Rust right now but actually in a table /// owned by the `wasm-bindgen` generated JS glue code. Eventually the ownership /// will transfer into wasm directly and this will likely become more efficient, /// but for now it may be slightly slow. pub struct JsValue { idx: u32, _marker: marker::PhantomData<*mut u8>, // not at all threadsafe } const JSIDX_OFFSET: u32 = 32; // keep in sync with js/mod.rs const JSIDX_UNDEFINED: u32 = JSIDX_OFFSET + 0; const JSIDX_NULL: u32 = JSIDX_OFFSET + 1; const JSIDX_TRUE: u32 = JSIDX_OFFSET + 2; const JSIDX_FALSE: u32 = JSIDX_OFFSET + 3; const JSIDX_RESERVED: u32 = JSIDX_OFFSET + 4; impl JsValue { /// The `null` JS value constant. pub const NULL: JsValue = JsValue { idx: JSIDX_NULL, _marker: marker::PhantomData, }; /// The `undefined` JS value constant. pub const UNDEFINED: JsValue = JsValue { idx: JSIDX_UNDEFINED, _marker: marker::PhantomData, }; /// The `true` JS value constant. pub const TRUE: JsValue = JsValue { idx: JSIDX_TRUE, _marker: marker::PhantomData, }; /// The `false` JS value constant. pub const FALSE: JsValue = JsValue { idx: JSIDX_FALSE, _marker: marker::PhantomData, }; #[inline] fn _new(idx: u32) -> JsValue { JsValue { idx, _marker: marker::PhantomData, } } /// Creates a new JS value which is a string. /// /// The utf-8 string provided is copied to the JS heap and the string will /// be owned by the JS garbage collector. #[inline] pub fn from_str(s: &str) -> JsValue { unsafe { JsValue::_new(__wbindgen_string_new(s.as_ptr(), s.len())) } } /// Creates a new JS value which is a number. /// /// This function creates a JS value representing a number (a heap /// allocated number) and returns a handle to the JS version of it. #[inline] pub fn from_f64(n: f64) -> JsValue { unsafe { JsValue::_new(__wbindgen_number_new(n)) } } /// Creates a new JS value which is a boolean. /// /// This function creates a JS object representing a boolean (a heap /// allocated boolean) and returns a handle to the JS version of it. #[inline] pub fn from_bool(b: bool) -> JsValue { if b { JsValue::TRUE } else { JsValue::FALSE } } /// Creates a new JS value representing `undefined`. #[inline] pub fn undefined() -> JsValue { JsValue::UNDEFINED } /// Creates a new JS value representing `null`. #[inline] pub fn null() -> JsValue { JsValue::NULL } /// Creates a new JS symbol with the optional description specified. /// /// This function will invoke the `Symbol` constructor in JS and return the /// JS object corresponding to the symbol created. pub fn symbol(description: Option<&str>) -> JsValue { unsafe { match description { Some(description) => JsValue::_new(__wbindgen_symbol_named_new( description.as_ptr(), description.len(), )), None => JsValue::_new(__wbindgen_symbol_anonymous_new()), } } } /// Creates a new `JsValue` from the JSON serialization of the object `t` /// provided. /// /// This function will serialize the provided value `t` to a JSON string, /// send the JSON string to JS, parse it into a JS object, and then return /// a handle to the JS object. This is unlikely to be super speedy so it's /// not recommended for large payloads, but it's a nice to have in some /// situations! /// /// Usage of this API requires activating the `serde-serialize` feature of /// the `wasm-bindgen` crate. /// /// # Errors /// /// Returns any error encountered when serializing `T` into JSON. #[cfg(feature = "serde-serialize")] pub fn from_serde<T>(t: &T) -> serde_json::Result<JsValue> where T: serde::ser::Serialize + ?Sized, { let s = serde_json::to_string(t)?; unsafe { Ok(JsValue::_new(__wbindgen_json_parse(s.as_ptr(), s.len()))) } } /// Invokes `JSON.stringify` on this value and then parses the resulting /// JSON into an arbitrary Rust value. /// /// This function will first call `JSON.stringify` on the `JsValue` itself. /// The resulting string is then passed into Rust which then parses it as /// JSON into the resulting value. /// /// Usage of this API requires activating the `serde-serialize` feature of /// the `wasm-bindgen` crate. /// /// # Errors /// /// Returns any error encountered when parsing the JSON into a `T`. #[cfg(feature = "serde-serialize")] pub fn into_serde<T>(&self) -> serde_json::Result<T> where T: for<'a> serde::de::Deserialize<'a>, { unsafe { let ret = __wbindgen_json_serialize(self.idx); let s = String::from_abi(ret); serde_json::from_str(&s) } } /// Returns the `f64` value of this JS value if it's an instance of a /// number. /// /// If this JS value is not an instance of a number then this returns /// `None`. pub fn as_f64(&self) -> Option<f64> { unsafe { FromWasmAbi::from_abi(__wbindgen_number_get(self.idx)) } } /// Tests whether this JS value is a JS string. pub fn is_string(&self) -> bool { unsafe { __wbindgen_is_string(self.idx) == 1 } } /// If this JS value is a string value, this function copies the JS string /// value into wasm linear memory, encoded as UTF-8, and returns it as a /// Rust `String`. /// /// To avoid the copying and re-encoding, consider the /// `JsString::try_from()` function from [js-sys](https://docs.rs/js-sys) /// instead. /// /// If this JS value is not an instance of a string or if it's not valid /// utf-8 then this returns `None`. /// /// # UTF-16 vs UTF-8 /// /// JavaScript strings in general are encoded as UTF-16, but Rust strings /// are encoded as UTF-8. This can cause the Rust string to look a bit /// different than the JS string sometimes. For more details see the /// [documentation about the `str` type][caveats] which contains a few /// caveats about the encodings. /// /// [caveats]: https://rustwasm.github.io/docs/wasm-bindgen/reference/types/str.html #[cfg(feature = "std")] pub fn as_string(&self) -> Option<String> { unsafe { FromWasmAbi::from_abi(__wbindgen_string_get(self.idx)) } } /// Returns the `bool` value of this JS value if it's an instance of a /// boolean. /// /// If this JS value is not an instance of a boolean then this returns /// `None`. pub fn as_bool(&self) -> Option<bool> { unsafe { match __wbindgen_boolean_get(self.idx) { 0 => Some(false), 1 => Some(true), _ => None, } } } /// Tests whether this JS value is `null` #[inline] pub fn is_null(&self) -> bool { unsafe { __wbindgen_is_null(self.idx) == 1 } } /// Tests whether this JS value is `undefined` #[inline] pub fn is_undefined(&self) -> bool { unsafe { __wbindgen_is_undefined(self.idx) == 1 } } /// Tests whether the type of this JS value is `symbol` #[inline] pub fn is_symbol(&self) -> bool { unsafe { __wbindgen_is_symbol(self.idx) == 1 } } /// Tests whether `typeof self == "object" && self !== null`. #[inline] pub fn is_object(&self) -> bool { unsafe { __wbindgen_is_object(self.idx) == 1 } } /// Tests whether the type of this JS value is `function`. #[inline] pub fn is_function(&self) -> bool { unsafe { __wbindgen_is_function(self.idx) == 1 } } /// Tests whether the value is ["truthy"]. /// /// ["truthy"]: https://developer.mozilla.org/en-US/docs/Glossary/Truthy #[inline] pub fn is_truthy(&self) -> bool { !self.is_falsy() } /// Tests whether the value is ["falsy"]. /// /// ["falsy"]: https://developer.mozilla.org/en-US/docs/Glossary/Falsy #[inline] pub fn is_falsy(&self) -> bool { unsafe { __wbindgen_is_falsy(self.idx) == 1 } } /// Get a string representation of the JavaScript object for debugging #[cfg(feature = "std")] fn as_debug_string(&self) -> String { unsafe { let mut ret = [0; 2]; __wbindgen_debug_string(&mut ret, self.idx); let data = Vec::from_raw_parts(ret[0] as *mut u8, ret[1], ret[1]); String::from_utf8_unchecked(data) } } } impl PartialEq for JsValue { #[inline] fn eq(&self, other: &JsValue) -> bool { unsafe { __wbindgen_jsval_eq(self.idx, other.idx) != 0 } } } impl PartialEq<bool> for JsValue { #[inline] fn eq(&self, other: &bool) -> bool { self.as_bool() == Some(*other) } } impl PartialEq<str> for JsValue { #[inline] fn eq(&self, other: &str) -> bool { *self == JsValue::from_str(other) } } impl<'a> PartialEq<&'a str> for JsValue { #[inline] fn eq(&self, other: &&'a str) -> bool { <JsValue as PartialEq<str>>::eq(self, other) } } if_std! { impl PartialEq<String> for JsValue { #[inline] fn eq(&self, other: &String) -> bool { <JsValue as PartialEq<str>>::eq(self, other) } } impl<'a> PartialEq<&'a String> for JsValue { #[inline] fn eq(&self, other: &&'a String) -> bool { <JsValue as PartialEq<str>>::eq(self, other) } } } impl<'a> From<&'a str> for JsValue { #[inline] fn from(s: &'a str) -> JsValue { JsValue::from_str(s) } } if_std! { impl<'a> From<&'a String> for JsValue { #[inline] fn from(s: &'a String) -> JsValue { JsValue::from_str(s) } } impl From<String> for JsValue { #[inline] fn from(s: String) -> JsValue { JsValue::from_str(&s) } } } impl From<bool> for JsValue { #[inline] fn from(s: bool) -> JsValue { JsValue::from_bool(s) } } impl<'a, T> From<&'a T> for JsValue where T: JsCast, { #[inline] fn from(s: &'a T) -> JsValue { s.as_ref().clone() } } impl<T> From<Option<T>> for JsValue where JsValue: From<T>, { #[inline] fn from(s: Option<T>) -> JsValue { match s { Some(s) => s.into(), None => JsValue::undefined(), } } } impl JsCast for JsValue { // everything is a `JsValue`! #[inline] fn instanceof(_val: &JsValue) -> bool { true } #[inline] fn unchecked_from_js(val: JsValue) -> Self { val } #[inline] fn unchecked_from_js_ref(val: &JsValue) -> &Self { val } } impl AsRef<JsValue> for JsValue { #[inline] fn as_ref(&self) -> &JsValue { self } } macro_rules! numbers { ($($n:ident)*) => ($( impl PartialEq<$n> for JsValue { #[inline] fn eq(&self, other: &$n) -> bool { self.as_f64() == Some(f64::from(*other)) } } impl From<$n> for JsValue { #[inline] fn from(n: $n) -> JsValue { JsValue::from_f64(n.into()) } } )*) } numbers! { i8 u8 i16 u16 i32 u32 f32 f64 } externs! { #[link(wasm_import_module = "__wbindgen_placeholder__")] extern "C" { fn __wbindgen_object_clone_ref(idx: u32) -> u32; fn __wbindgen_object_drop_ref(idx: u32) -> (); fn __wbindgen_string_new(ptr: *const u8, len: usize) -> u32; fn __wbindgen_number_new(f: f64) -> u32; fn __wbindgen_symbol_named_new(ptr: *const u8, len: usize) -> u32; fn __wbindgen_symbol_anonymous_new() -> u32; fn __wbindgen_externref_heap_live_count() -> u32; fn __wbindgen_is_null(idx: u32) -> u32; fn __wbindgen_is_undefined(idx: u32) -> u32; fn __wbindgen_is_symbol(idx: u32) -> u32; fn __wbindgen_is_object(idx: u32) -> u32; fn __wbindgen_is_function(idx: u32) -> u32; fn __wbindgen_is_string(idx: u32) -> u32; fn __wbindgen_is_falsy(idx: u32) -> u32; fn __wbindgen_number_get(idx: u32) -> WasmOptionalF64; fn __wbindgen_boolean_get(idx: u32) -> u32; fn __wbindgen_string_get(idx: u32) -> WasmSlice; fn __wbindgen_debug_string(ret: *mut [usize; 2], idx: u32) -> (); fn __wbindgen_throw(a: *const u8, b: usize) -> !; fn __wbindgen_rethrow(a: u32) -> !; fn __wbindgen_cb_drop(idx: u32) -> u32; fn __wbindgen_describe(v: u32) -> (); fn __wbindgen_describe_closure(a: u32, b: u32, c: u32) -> u32; fn __wbindgen_json_parse(ptr: *const u8, len: usize) -> u32; fn __wbindgen_json_serialize(idx: u32) -> WasmSlice; fn __wbindgen_jsval_eq(a: u32, b: u32) -> u32; fn __wbindgen_memory() -> u32; fn __wbindgen_module() -> u32; fn __wbindgen_function_table() -> u32; } } impl Clone for JsValue { #[inline] fn clone(&self) -> JsValue { unsafe { let idx = __wbindgen_object_clone_ref(self.idx); JsValue::_new(idx) } } } #[cfg(feature = "std")] impl fmt::Debug for JsValue { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "JsValue({})", self.as_debug_string()) } } #[cfg(not(feature = "std"))] impl fmt::Debug for JsValue { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { f.write_str("JsValue") } } impl Drop for JsValue { #[inline] fn drop(&mut self) { unsafe { // We definitely should never drop anything in the stack area debug_assert!(self.idx >= JSIDX_OFFSET, "free of stack slot {}", self.idx); // Otherwise if we're not dropping one of our reserved values, // actually call the intrinsic. See #1054 for eventually removing // this branch. if self.idx >= JSIDX_RESERVED { __wbindgen_object_drop_ref(self.idx); } } } } /// Wrapper type for imported statics. /// /// This type is used whenever a `static` is imported from a JS module, for /// example this import: /// /// ```ignore /// #[wasm_bindgen] /// extern "C" { /// static console: JsValue; /// } /// ``` /// /// will generate in Rust a value that looks like: /// /// ```ignore /// static console: JsStatic<JsValue> = ...; /// ``` /// /// This type implements `Deref` to the inner type so it's typically used as if /// it were `&T`. #[cfg(feature = "std")] pub struct JsStatic<T: 'static> { #[doc(hidden)] pub __inner: &'static std::thread::LocalKey<T>, } #[cfg(feature = "std")] impl<T: FromWasmAbi + 'static> Deref for JsStatic<T> { type Target = T; fn deref(&self) -> &T { // We know that our tls key is never overwritten after initialization, // so it should be safe (on that axis at least) to hand out a reference // that lives longer than the closure below. // // FIXME: this is not sound if we ever implement thread exit hooks on // wasm, as the pointer will eventually be invalidated but you can get // `&'static T` from this interface. We... probably need to deprecate // and/or remove this interface nowadays. unsafe { self.__inner.with(|ptr| &*(ptr as *const T)) } } } #[cold] #[inline(never)] #[deprecated(note = "renamed to `throw_str`")] #[doc(hidden)] pub fn throw(s: &str) -> ! { throw_str(s) } /// Throws a JS exception. /// /// This function will throw a JS exception with the message provided. The /// function will not return as the wasm stack will be popped when the exception /// is thrown. /// /// Note that it is very easy to leak memory with this function because this /// function, unlike `panic!` on other platforms, **will not run destructors**. /// It's recommended to return a `Result` where possible to avoid the worry of /// leaks. #[cold] #[inline(never)] pub fn throw_str(s: &str) -> ! { unsafe { __wbindgen_throw(s.as_ptr(), s.len()); } } /// Rethrow a JS exception /// /// This function will throw a JS exception with the JS value provided. This /// function will not return and the wasm stack will be popped until the point /// of entry of wasm itself. /// /// Note that it is very easy to leak memory with this function because this /// function, unlike `panic!` on other platforms, **will not run destructors**. /// It's recommended to return a `Result` where possible to avoid the worry of /// leaks. #[cold] #[inline(never)] pub fn throw_val(s: JsValue) -> ! { unsafe { let idx = s.idx; mem::forget(s); __wbindgen_rethrow(idx); } } /// Get the count of live `externref`s / `JsValue`s in `wasm-bindgen`'s heap. /// /// ## Usage /// /// This is intended for debugging and writing tests. /// /// To write a test that asserts against unnecessarily keeping `anref`s / /// `JsValue`s alive: /// /// * get an initial live count, /// /// * perform some series of operations or function calls that should clean up /// after themselves, and should not keep holding onto `externref`s / `JsValue`s /// after completion, /// /// * get the final live count, /// /// * and assert that the initial and final counts are the same. /// /// ## What is Counted /// /// Note that this only counts the *owned* `externref`s / `JsValue`s that end up in /// `wasm-bindgen`'s heap. It does not count borrowed `externref`s / `JsValue`s /// that are on its stack. /// /// For example, these `JsValue`s are accounted for: /// /// ```ignore /// #[wasm_bindgen] /// pub fn my_function(this_is_counted: JsValue) { /// let also_counted = JsValue::from_str("hi"); /// assert!(wasm_bindgen::externref_heap_live_count() >= 2); /// } /// ``` /// /// While this borrowed `JsValue` ends up on the stack, not the heap, and /// therefore is not accounted for: /// /// ```ignore /// #[wasm_bindgen] /// pub fn my_other_function(this_is_not_counted: &JsValue) { /// // ... /// } /// ``` pub fn externref_heap_live_count() -> u32 { unsafe { __wbindgen_externref_heap_live_count() } } #[doc(hidden)] pub fn anyref_heap_live_count() -> u32 { externref_heap_live_count() } /// An extension trait for `Option<T>` and `Result<T, E>` for unwraping the `T` /// value, or throwing a JS error if it is not available. /// /// These methods should have a smaller code size footprint than the normal /// `Option::unwrap` and `Option::expect` methods, but they are specific to /// working with wasm and JS. /// /// On non-wasm32 targets, defaults to the normal unwrap/expect calls. /// /// # Example /// /// ``` /// use wasm_bindgen::prelude::*; /// /// // If the value is `Option::Some` or `Result::Ok`, then we just get the /// // contained `T` value. /// let x = Some(42); /// assert_eq!(x.unwrap_throw(), 42); /// /// let y: Option<i32> = None; /// /// // This call would throw an error to JS! /// // /// // y.unwrap_throw() /// // /// // And this call would throw an error to JS with a custom error message! /// // /// // y.expect_throw("woopsie daisy!") /// ``` pub trait UnwrapThrowExt<T>: Sized { /// Unwrap this `Option` or `Result`, but instead of panicking on failure, /// throw an exception to JavaScript. fn unwrap_throw(self) -> T { self.expect_throw("`unwrap_throw` failed") } /// Unwrap this container's `T` value, or throw an error to JS with the /// given message if the `T` value is unavailable (e.g. an `Option<T>` is /// `None`). fn expect_throw(self, message: &str) -> T; } impl<T> UnwrapThrowExt<T> for Option<T> { fn expect_throw(self, message: &str) -> T { if cfg!(all(target_arch = "wasm32", not(target_os = "emscripten"))) { match self { Some(val) => val, None => throw_str(message), } } else { self.expect(message) } } } impl<T, E> UnwrapThrowExt<T> for Result<T, E> where E: core::fmt::Debug, { fn expect_throw(self, message: &str) -> T { if cfg!(all(target_arch = "wasm32", not(target_os = "emscripten"))) { match self { Ok(val) => val, Err(_) => throw_str(message), } } else { self.expect(message) } } } /// Returns a handle to this wasm instance's `WebAssembly.Module` /// /// Note that this is only available when the final wasm app is built with /// `--target no-modules`, it's not recommended to rely on this API yet! This is /// largely just an experimental addition to enable threading demos. Using this /// may prevent your wasm module from building down the road. #[doc(hidden)] pub fn module() -> JsValue { unsafe { JsValue::_new(__wbindgen_module()) } } /// Returns a handle to this wasm instance's `WebAssembly.Memory` pub fn memory() -> JsValue { unsafe { JsValue::_new(__wbindgen_memory()) } } /// Returns a handle to this wasm instance's `WebAssembly.Table` which is the /// indirect function table used by Rust pub fn function_table() -> JsValue { unsafe { JsValue::_new(__wbindgen_function_table()) } } #[doc(hidden)] pub mod __rt { use crate::JsValue; use core::cell::{Cell, UnsafeCell}; use core::ops::{Deref, DerefMut}; pub extern crate core; #[cfg(feature = "std")] pub extern crate std; #[macro_export] #[doc(hidden)] #[cfg(feature = "std")] macro_rules! __wbindgen_if_not_std { ($($i:item)*) => {}; } #[macro_export] #[doc(hidden)] #[cfg(not(feature = "std"))] macro_rules! __wbindgen_if_not_std { ($($i:item)*) => ($($i)*) } #[inline] pub fn assert_not_null<T>(s: *mut T) { if s.is_null() { throw_null(); } } #[cold] #[inline(never)] fn throw_null() -> ! { super::throw_str("null pointer passed to rust"); } /// A vendored version of `RefCell` from the standard library. /// /// Now why, you may ask, would we do that? Surely `RefCell` in libstd is /// quite good. And you're right, it is indeed quite good! Functionally /// nothing more is needed from `RefCell` in the standard library but for /// now this crate is also sort of optimizing for compiled code size. /// /// One major factor to larger binaries in Rust is when a panic happens. /// Panicking in the standard library involves a fair bit of machinery /// (formatting, panic hooks, synchronization, etc). It's all worthwhile if /// you need it but for something like `WasmRefCell` here we don't actually /// need all that! /// /// This is just a wrapper around all Rust objects passed to JS intended to /// guard accidental reentrancy, so this vendored version is intended solely /// to not panic in libstd. Instead when it "panics" it calls our `throw` /// function in this crate which raises an error in JS. pub struct WasmRefCell<T: ?Sized> { borrow: Cell<usize>, value: UnsafeCell<T>, } impl<T: ?Sized> WasmRefCell<T> { pub fn new(value: T) -> WasmRefCell<T> where T: Sized, { WasmRefCell { value: UnsafeCell::new(value), borrow: Cell::new(0), } } pub fn get_mut(&mut self) -> &mut T { unsafe { &mut *self.value.get() } } pub fn borrow(&self) -> Ref<T> { unsafe { if self.borrow.get() == usize::max_value() { borrow_fail(); } self.borrow.set(self.borrow.get() + 1); Ref { value: &*self.value.get(), borrow: &self.borrow, } } } pub fn borrow_mut(&self) -> RefMut<T> { unsafe { if self.borrow.get() != 0 { borrow_fail(); } self.borrow.set(usize::max_value()); RefMut { value: &mut *self.value.get(), borrow: &self.borrow, } } } pub fn into_inner(self) -> T where T: Sized, { self.value.into_inner() } } pub struct Ref<'b, T: ?Sized + 'b> { value: &'b T, borrow: &'b Cell<usize>, } impl<'b, T: ?Sized> Deref for Ref<'b, T> { type Target = T; #[inline] fn deref(&self) -> &T { self.value } } impl<'b, T: ?Sized> Drop for Ref<'b, T> { fn drop(&mut self) { self.borrow.set(self.borrow.get() - 1); } } pub struct RefMut<'b, T: ?Sized + 'b> { value: &'b mut T, borrow: &'b Cell<usize>, } impl<'b, T: ?Sized> Deref for RefMut<'b, T> { type Target = T; #[inline] fn deref(&self) -> &T { self.value } } impl<'b, T: ?Sized> DerefMut for RefMut<'b, T> { #[inline] fn deref_mut(&mut self) -> &mut T { self.value } } impl<'b, T: ?Sized> Drop for RefMut<'b, T> { fn drop(&mut self) { self.borrow.set(0); } } fn borrow_fail() -> ! { super::throw_str( "recursive use of an object detected which would lead to \ unsafe aliasing in rust", ); } if_std! { use std::alloc::{alloc, dealloc, realloc, Layout}; use std::mem; #[no_mangle] pub extern "C" fn __wbindgen_malloc(size: usize) -> *mut u8 { let align = mem::align_of::<usize>(); if let Ok(layout) = Layout::from_size_align(size, align) { unsafe { if layout.size() > 0 { let ptr = alloc(layout); if !ptr.is_null() { return ptr } } else { return align as *mut u8 } } } malloc_failure(); } #[no_mangle] pub unsafe extern "C" fn __wbindgen_realloc(ptr: *mut u8, old_size: usize, new_size: usize) -> *mut u8 { let align = mem::align_of::<usize>(); debug_assert!(old_size > 0); debug_assert!(new_size > 0); if let Ok(layout) = Layout::from_size_align(old_size, align) { let ptr = realloc(ptr, layout, new_size); if !ptr.is_null() { return ptr } } malloc_failure(); } #[cold] fn malloc_failure() -> ! { if cfg!(debug_assertions) { super::throw_str("invalid malloc request") } else { std::process::abort(); } } #[no_mangle] pub unsafe extern "C" fn __wbindgen_free(ptr: *mut u8, size: usize) { // This happens for zero-length slices, and in that case `ptr` is // likely bogus so don't actually send this to the system allocator if size == 0 { return } let align = mem::align_of::<usize>(); let layout = Layout::from_size_align_unchecked(size, align); dealloc(ptr, layout); } } /// This is a curious function necessary to get wasm-bindgen working today, /// and it's a bit of an unfortunate hack. /// /// The general problem is that somehow we need the above two symbols to /// exist in the final output binary (__wbindgen_malloc and /// __wbindgen_free). These symbols may be called by JS for various /// bindings, so we for sure need to make sure they're exported. /// /// The problem arises, though, when what if no Rust code uses the symbols? /// For all intents and purposes it looks to LLVM and the linker like the /// above two symbols are dead code, so they're completely discarded! /// /// Specifically what happens is this: /// /// * The above two symbols are generated into some object file inside of /// libwasm_bindgen.rlib /// * The linker, LLD, will not load this object file unless *some* symbol /// is loaded from the object. In this case, if the Rust code never calls /// __wbindgen_malloc or __wbindgen_free then the symbols never get linked /// in. /// * Later when `wasm-bindgen` attempts to use the symbols they don't /// exist, causing an error. /// /// This function is a weird hack for this problem. We inject a call to this /// function in all generated code. Usage of this function should then /// ensure that the above two intrinsics are translated. /// /// Due to how rustc creates object files this function (and anything inside /// it) will be placed into the same object file as the two intrinsics /// above. That means if this function is called and referenced we'll pull /// in the object file and link the intrinsics. /// /// Ideas for how to improve this are most welcome! pub fn link_mem_intrinsics() { crate::externref::link_intrinsics(); } static mut GLOBAL_EXNDATA: [u32; 2] = [0; 2]; #[no_mangle] pub unsafe extern "C" fn __wbindgen_exn_store(idx: u32) { debug_assert_eq!(GLOBAL_EXNDATA[0], 0); GLOBAL_EXNDATA[0] = 1; GLOBAL_EXNDATA[1] = idx; } pub fn take_last_exception() -> Result<(), super::JsValue> { unsafe { let ret = if GLOBAL_EXNDATA[0] == 1 { Err(super::JsValue::_new(GLOBAL_EXNDATA[1])) } else { Ok(()) }; GLOBAL_EXNDATA[0] = 0; GLOBAL_EXNDATA[1] = 0; return ret; } } /// An internal helper trait for usage in `#[wasm_bindgen]` on `async` /// functions to convert the return value of the function to /// `Result<JsValue, JsValue>` which is what we'll return to JS (where an /// error is a failed future). pub trait IntoJsResult { fn into_js_result(self) -> Result<JsValue, JsValue>; } impl IntoJsResult for () { fn into_js_result(self) -> Result<JsValue, JsValue> { Ok(JsValue::undefined()) } } impl<T: Into<JsValue>> IntoJsResult for T { fn into_js_result(self) -> Result<JsValue, JsValue> { Ok(self.into()) } } impl<T: Into<JsValue>, E: Into<JsValue>> IntoJsResult for Result<T, E> { fn into_js_result(self) -> Result<JsValue, JsValue> { match self { Ok(e) => Ok(e.into()), Err(e) => Err(e.into()), } } } impl<E: Into<JsValue>> IntoJsResult for Result<(), E> { fn into_js_result(self) -> Result<JsValue, JsValue> { match self { Ok(()) => Ok(JsValue::undefined()), Err(e) => Err(e.into()), } } } /// An internal helper trait for usage in `#[wasm_bindgen(start)]` /// functions to throw the error (if it is `Err`). pub trait Start { fn start(self); } impl Start for () { #[inline] fn start(self) {} } impl<E: Into<JsValue>> Start for Result<(), E> { #[inline] fn start(self) { if let Err(e) = self { crate::throw_val(e.into()); } } } } /// A wrapper type around slices and vectors for binding the `Uint8ClampedArray` /// array in JS. /// /// If you need to invoke a JS API which must take `Uint8ClampedArray` array, /// then you can define it as taking one of these types: /// /// * `Clamped<&[u8]>` /// * `Clamped<&mut [u8]>` /// * `Clamped<Vec<u8>>` /// /// All of these types will show up as `Uint8ClampedArray` in JS and will have /// different forms of ownership in Rust. #[derive(Copy, Clone, PartialEq, Debug, Eq)] pub struct Clamped<T>(pub T); impl<T> Deref for Clamped<T> { type Target = T; fn deref(&self) -> &T { &self.0 } } impl<T> DerefMut for Clamped<T> { fn deref_mut(&mut self) -> &mut T { &mut self.0 } }