wasm_encoder/component/
canonicals.rs

1use crate::{ComponentSection, ComponentSectionId, ComponentValType, Encode, encode_section};
2use alloc::vec::Vec;
3
4/// Represents options for canonical function definitions.
5#[derive(Debug, Clone, Copy, PartialEq, Eq)]
6pub enum CanonicalOption {
7    /// The string types in the function signature are UTF-8 encoded.
8    UTF8,
9    /// The string types in the function signature are UTF-16 encoded.
10    UTF16,
11    /// The string types in the function signature are compact UTF-16 encoded.
12    CompactUTF16,
13    /// The memory to use if the lifting or lowering of a function requires memory access.
14    ///
15    /// The value is an index to a core memory.
16    Memory(u32),
17    /// The realloc function to use if the lifting or lowering of a function requires memory
18    /// allocation.
19    ///
20    /// The value is an index to a core function of type `(func (param i32 i32 i32 i32) (result i32))`.
21    Realloc(u32),
22    /// The post-return function to use if the lifting of a function requires
23    /// cleanup after the function returns.
24    PostReturn(u32),
25    /// Indicates that specified function should be lifted or lowered using the `async` ABI.
26    Async,
27    /// The function to use if the async lifting of a function should receive task/stream/future progress events
28    /// using a callback.
29    Callback(u32),
30    /// The core function type to lower a component function into.
31    CoreType(u32),
32    /// Use the GC variant of the canonical ABI.
33    Gc,
34}
35
36impl Encode for CanonicalOption {
37    fn encode(&self, sink: &mut Vec<u8>) {
38        match self {
39            Self::UTF8 => sink.push(0x00),
40            Self::UTF16 => sink.push(0x01),
41            Self::CompactUTF16 => sink.push(0x02),
42            Self::Memory(idx) => {
43                sink.push(0x03);
44                idx.encode(sink);
45            }
46            Self::Realloc(idx) => {
47                sink.push(0x04);
48                idx.encode(sink);
49            }
50            Self::PostReturn(idx) => {
51                sink.push(0x05);
52                idx.encode(sink);
53            }
54            Self::Async => {
55                sink.push(0x06);
56            }
57            Self::Callback(idx) => {
58                sink.push(0x07);
59                idx.encode(sink);
60            }
61            Self::CoreType(idx) => {
62                sink.push(0x08);
63                idx.encode(sink);
64            }
65            Self::Gc => {
66                sink.push(0x09);
67            }
68        }
69    }
70}
71
72/// An encoder for the canonical function section of WebAssembly components.
73///
74/// # Example
75///
76/// ```
77/// use wasm_encoder::{Component, CanonicalFunctionSection, CanonicalOption};
78///
79/// let mut functions = CanonicalFunctionSection::new();
80/// functions.lift(0, 0, [CanonicalOption::UTF8]);
81///
82/// let mut component = Component::new();
83/// component.section(&functions);
84///
85/// let bytes = component.finish();
86/// ```
87#[derive(Clone, Debug, Default)]
88pub struct CanonicalFunctionSection {
89    bytes: Vec<u8>,
90    num_added: u32,
91}
92
93impl CanonicalFunctionSection {
94    /// Construct a new component function section encoder.
95    pub fn new() -> Self {
96        Self::default()
97    }
98
99    /// The number of functions in the section.
100    pub fn len(&self) -> u32 {
101        self.num_added
102    }
103
104    /// Determines if the section is empty.
105    pub fn is_empty(&self) -> bool {
106        self.num_added == 0
107    }
108
109    /// Define a function that will lift a core WebAssembly function to the canonical ABI.
110    pub fn lift<O>(&mut self, core_func_index: u32, type_index: u32, options: O) -> &mut Self
111    where
112        O: IntoIterator<Item = CanonicalOption>,
113        O::IntoIter: ExactSizeIterator,
114    {
115        self.bytes.push(0x00);
116        self.bytes.push(0x00);
117        core_func_index.encode(&mut self.bytes);
118        self.encode_options(options);
119        type_index.encode(&mut self.bytes);
120        self.num_added += 1;
121        self
122    }
123
124    /// Define a function that will lower a canonical ABI function to a core WebAssembly function.
125    pub fn lower<O>(&mut self, func_index: u32, options: O) -> &mut Self
126    where
127        O: IntoIterator<Item = CanonicalOption>,
128        O::IntoIter: ExactSizeIterator,
129    {
130        self.bytes.push(0x01);
131        self.bytes.push(0x00);
132        func_index.encode(&mut self.bytes);
133        self.encode_options(options);
134        self.num_added += 1;
135        self
136    }
137
138    /// Defines a function which will create an owned handle to the resource
139    /// specified by `ty_index`.
140    pub fn resource_new(&mut self, ty_index: u32) -> &mut Self {
141        self.bytes.push(0x02);
142        ty_index.encode(&mut self.bytes);
143        self.num_added += 1;
144        self
145    }
146
147    /// Defines a function which will drop the specified type of handle.
148    pub fn resource_drop(&mut self, ty_index: u32) -> &mut Self {
149        self.bytes.push(0x03);
150        ty_index.encode(&mut self.bytes);
151        self.num_added += 1;
152        self
153    }
154
155    /// Defines a function which will drop the specified type of handle.
156    pub fn resource_drop_async(&mut self, ty_index: u32) -> &mut Self {
157        self.bytes.push(0x07);
158        ty_index.encode(&mut self.bytes);
159        self.num_added += 1;
160        self
161    }
162
163    /// Defines a function which will return the representation of the specified
164    /// resource type.
165    pub fn resource_rep(&mut self, ty_index: u32) -> &mut Self {
166        self.bytes.push(0x04);
167        ty_index.encode(&mut self.bytes);
168        self.num_added += 1;
169        self
170    }
171
172    /// Defines a function which will spawn a new thread by invoking a shared
173    /// function of type `ty_index`.
174    pub fn thread_spawn_ref(&mut self, ty_index: u32) -> &mut Self {
175        self.bytes.push(0x40);
176        ty_index.encode(&mut self.bytes);
177        self.num_added += 1;
178        self
179    }
180
181    /// Defines a function which will spawn a new thread by invoking a shared
182    /// function indirectly through a `funcref` table.
183    pub fn thread_spawn_indirect(&mut self, ty_index: u32, table_index: u32) -> &mut Self {
184        self.bytes.push(0x41);
185        ty_index.encode(&mut self.bytes);
186        table_index.encode(&mut self.bytes);
187        self.num_added += 1;
188        self
189    }
190
191    /// Defines a function which will return the number of threads that can be
192    /// expected to execute concurrently.
193    pub fn thread_available_parallelism(&mut self) -> &mut Self {
194        self.bytes.push(0x42);
195        self.num_added += 1;
196        self
197    }
198
199    /// Defines a function which tells the host to enable or disable
200    /// backpressure for the caller's instance.  When backpressure is enabled,
201    /// the host must not start any new calls to that instance until
202    /// backpressure is disabled.
203    pub fn backpressure_set(&mut self) -> &mut Self {
204        self.bytes.push(0x08);
205        self.num_added += 1;
206        self
207    }
208
209    /// Defines a function which tells the host to increment the backpressure
210    /// counter.
211    pub fn backpressure_inc(&mut self) -> &mut Self {
212        self.bytes.push(0x24);
213        self.num_added += 1;
214        self
215    }
216
217    /// Defines a function which tells the host to decrement the backpressure
218    /// counter.
219    pub fn backpressure_dec(&mut self) -> &mut Self {
220        self.bytes.push(0x25);
221        self.num_added += 1;
222        self
223    }
224
225    /// Defines a function which returns a result to the caller of a lifted
226    /// export function.  This allows the callee to continue executing after
227    /// returning a result.
228    pub fn task_return<O>(&mut self, ty: Option<ComponentValType>, options: O) -> &mut Self
229    where
230        O: IntoIterator<Item = CanonicalOption>,
231        O::IntoIter: ExactSizeIterator,
232    {
233        self.bytes.push(0x09);
234        crate::encode_resultlist(&mut self.bytes, ty);
235        self.encode_options(options);
236        self.num_added += 1;
237        self
238    }
239
240    /// Defines a function to acknowledge cancellation of the current task.
241    pub fn task_cancel(&mut self) -> &mut Self {
242        self.bytes.push(0x05);
243        self.num_added += 1;
244        self
245    }
246
247    /// Defines a new `context.get` intrinsic of the ith slot.
248    pub fn context_get(&mut self, i: u32) -> &mut Self {
249        self.bytes.push(0x0a);
250        self.bytes.push(0x7f);
251        i.encode(&mut self.bytes);
252        self.num_added += 1;
253        self
254    }
255
256    /// Defines a new `context.set` intrinsic of the ith slot.
257    pub fn context_set(&mut self, i: u32) -> &mut Self {
258        self.bytes.push(0x0b);
259        self.bytes.push(0x7f);
260        i.encode(&mut self.bytes);
261        self.num_added += 1;
262        self
263    }
264
265    /// Defines a function which yields control to the host so that other tasks
266    /// are able to make progress, if any.
267    ///
268    /// If `cancellable` is true, the caller instance may be reentered.
269    pub fn thread_yield(&mut self, cancellable: bool) -> &mut Self {
270        self.bytes.push(0x0c);
271        self.bytes.push(if cancellable { 1 } else { 0 });
272        self.num_added += 1;
273        self
274    }
275
276    /// Defines a function to drop a specified task which has completed.
277    pub fn subtask_drop(&mut self) -> &mut Self {
278        self.bytes.push(0x0d);
279        self.num_added += 1;
280        self
281    }
282
283    /// Defines a function to cancel an in-progress task.
284    pub fn subtask_cancel(&mut self, async_: bool) -> &mut Self {
285        self.bytes.push(0x06);
286        self.bytes.push(if async_ { 1 } else { 0 });
287        self.num_added += 1;
288        self
289    }
290
291    /// Defines a function to create a new `stream` handle of the specified
292    /// type.
293    pub fn stream_new(&mut self, ty: u32) -> &mut Self {
294        self.bytes.push(0x0e);
295        ty.encode(&mut self.bytes);
296        self.num_added += 1;
297        self
298    }
299
300    /// Defines a function to read from a `stream` of the specified type.
301    pub fn stream_read<O>(&mut self, ty: u32, options: O) -> &mut Self
302    where
303        O: IntoIterator<Item = CanonicalOption>,
304        O::IntoIter: ExactSizeIterator,
305    {
306        self.bytes.push(0x0f);
307        ty.encode(&mut self.bytes);
308        self.encode_options(options);
309        self.num_added += 1;
310        self
311    }
312
313    /// Defines a function to write to a `stream` of the specified type.
314    pub fn stream_write<O>(&mut self, ty: u32, options: O) -> &mut Self
315    where
316        O: IntoIterator<Item = CanonicalOption>,
317        O::IntoIter: ExactSizeIterator,
318    {
319        self.bytes.push(0x10);
320        ty.encode(&mut self.bytes);
321        self.encode_options(options);
322        self.num_added += 1;
323        self
324    }
325
326    /// Defines a function to cancel an in-progress read from a `stream` of the
327    /// specified type.
328    pub fn stream_cancel_read(&mut self, ty: u32, async_: bool) -> &mut Self {
329        self.bytes.push(0x11);
330        ty.encode(&mut self.bytes);
331        self.bytes.push(if async_ { 1 } else { 0 });
332        self.num_added += 1;
333        self
334    }
335
336    /// Defines a function to cancel an in-progress write to a `stream` of the
337    /// specified type.
338    pub fn stream_cancel_write(&mut self, ty: u32, async_: bool) -> &mut Self {
339        self.bytes.push(0x12);
340        ty.encode(&mut self.bytes);
341        self.bytes.push(if async_ { 1 } else { 0 });
342        self.num_added += 1;
343        self
344    }
345
346    /// Defines a function to drop the readable end of a `stream` of the
347    /// specified type.
348    pub fn stream_drop_readable(&mut self, ty: u32) -> &mut Self {
349        self.bytes.push(0x13);
350        ty.encode(&mut self.bytes);
351        self.num_added += 1;
352        self
353    }
354
355    /// Defines a function to drop the writable end of a `stream` of the
356    /// specified type.
357    pub fn stream_drop_writable(&mut self, ty: u32) -> &mut Self {
358        self.bytes.push(0x14);
359        ty.encode(&mut self.bytes);
360        self.num_added += 1;
361        self
362    }
363
364    /// Defines a function to create a new `future` handle of the specified
365    /// type.
366    pub fn future_new(&mut self, ty: u32) -> &mut Self {
367        self.bytes.push(0x15);
368        ty.encode(&mut self.bytes);
369        self.num_added += 1;
370        self
371    }
372
373    /// Defines a function to read from a `future` of the specified type.
374    pub fn future_read<O>(&mut self, ty: u32, options: O) -> &mut Self
375    where
376        O: IntoIterator<Item = CanonicalOption>,
377        O::IntoIter: ExactSizeIterator,
378    {
379        self.bytes.push(0x16);
380        ty.encode(&mut self.bytes);
381        self.encode_options(options);
382        self.num_added += 1;
383        self
384    }
385
386    /// Defines a function to write to a `future` of the specified type.
387    pub fn future_write<O>(&mut self, ty: u32, options: O) -> &mut Self
388    where
389        O: IntoIterator<Item = CanonicalOption>,
390        O::IntoIter: ExactSizeIterator,
391    {
392        self.bytes.push(0x17);
393        ty.encode(&mut self.bytes);
394        self.encode_options(options);
395        self.num_added += 1;
396        self
397    }
398
399    /// Defines a function to cancel an in-progress read from a `future` of the
400    /// specified type.
401    pub fn future_cancel_read(&mut self, ty: u32, async_: bool) -> &mut Self {
402        self.bytes.push(0x18);
403        ty.encode(&mut self.bytes);
404        self.bytes.push(if async_ { 1 } else { 0 });
405        self.num_added += 1;
406        self
407    }
408
409    /// Defines a function to cancel an in-progress write to a `future` of the
410    /// specified type.
411    pub fn future_cancel_write(&mut self, ty: u32, async_: bool) -> &mut Self {
412        self.bytes.push(0x19);
413        ty.encode(&mut self.bytes);
414        self.bytes.push(if async_ { 1 } else { 0 });
415        self.num_added += 1;
416        self
417    }
418
419    /// Defines a function to drop the readable end of a `future` of the
420    /// specified type.
421    pub fn future_drop_readable(&mut self, ty: u32) -> &mut Self {
422        self.bytes.push(0x1a);
423        ty.encode(&mut self.bytes);
424        self.num_added += 1;
425        self
426    }
427
428    /// Defines a function to drop the writable end of a `future` of the
429    /// specified type.
430    pub fn future_drop_writable(&mut self, ty: u32) -> &mut Self {
431        self.bytes.push(0x1b);
432        ty.encode(&mut self.bytes);
433        self.num_added += 1;
434        self
435    }
436
437    /// Defines a function to create a new `error-context` with a specified
438    /// debug message.
439    pub fn error_context_new<O>(&mut self, options: O) -> &mut Self
440    where
441        O: IntoIterator<Item = CanonicalOption>,
442        O::IntoIter: ExactSizeIterator,
443    {
444        self.bytes.push(0x1c);
445        self.encode_options(options);
446        self.num_added += 1;
447        self
448    }
449
450    /// Defines a function to get the debug message for a specified
451    /// `error-context`.
452    ///
453    /// Note that the debug message might not necessarily match what was passed
454    /// to `error-context.new`.
455    pub fn error_context_debug_message<O>(&mut self, options: O) -> &mut Self
456    where
457        O: IntoIterator<Item = CanonicalOption>,
458        O::IntoIter: ExactSizeIterator,
459    {
460        self.bytes.push(0x1d);
461        self.encode_options(options);
462        self.num_added += 1;
463        self
464    }
465
466    /// Defines a function to drop a specified `error-context`.
467    pub fn error_context_drop(&mut self) -> &mut Self {
468        self.bytes.push(0x1e);
469        self.num_added += 1;
470        self
471    }
472
473    /// Declare a new `waitable-set.new` intrinsic, used to create a
474    /// `waitable-set` pseudo-resource.
475    pub fn waitable_set_new(&mut self) -> &mut Self {
476        self.bytes.push(0x1f);
477        self.num_added += 1;
478        self
479    }
480
481    /// Declare a new `waitable-set.wait` intrinsic, used to block on a
482    /// `waitable-set`.
483    pub fn waitable_set_wait(&mut self, async_: bool, memory: u32) -> &mut Self {
484        self.bytes.push(0x20);
485        self.bytes.push(if async_ { 1 } else { 0 });
486        memory.encode(&mut self.bytes);
487        self.num_added += 1;
488        self
489    }
490
491    /// Declare a new `waitable-set.wait` intrinsic, used to check, without
492    /// blocking, if anything in a `waitable-set` is ready.
493    pub fn waitable_set_poll(&mut self, async_: bool, memory: u32) -> &mut Self {
494        self.bytes.push(0x21);
495        self.bytes.push(if async_ { 1 } else { 0 });
496        memory.encode(&mut self.bytes);
497        self.num_added += 1;
498        self
499    }
500
501    /// Declare a new `waitable-set.drop` intrinsic, used to dispose a
502    /// `waitable-set` pseudo-resource.
503    pub fn waitable_set_drop(&mut self) -> &mut Self {
504        self.bytes.push(0x22);
505        self.num_added += 1;
506        self
507    }
508
509    /// Declare a new `waitable.join` intrinsic, used to add an item to a
510    /// `waitable-set`.
511    pub fn waitable_join(&mut self) -> &mut Self {
512        self.bytes.push(0x23);
513        self.num_added += 1;
514        self
515    }
516
517    /// Declare a new `thread.index` intrinsic, used to get the index of the
518    /// current thread.
519    pub fn thread_index(&mut self) -> &mut Self {
520        self.bytes.push(0x26);
521        self.num_added += 1;
522        self
523    }
524
525    /// Declare a new `thread.new_indirect` intrinsic, used to create a new
526    /// thread by invoking a function indirectly through a `funcref` table.
527    pub fn thread_new_indirect(&mut self, ty_index: u32, table_index: u32) -> &mut Self {
528        self.bytes.push(0x27);
529        ty_index.encode(&mut self.bytes);
530        table_index.encode(&mut self.bytes);
531        self.num_added += 1;
532        self
533    }
534
535    /// Declare a new `thread.switch-to` intrinsic, used to switch execution to
536    /// another thread.
537    pub fn thread_switch_to(&mut self, cancellable: bool) -> &mut Self {
538        self.bytes.push(0x28);
539        self.bytes.push(if cancellable { 1 } else { 0 });
540        self.num_added += 1;
541        self
542    }
543
544    /// Declare a new `thread.suspend` intrinsic, used to suspend execution of
545    /// the current thread.
546    pub fn thread_suspend(&mut self, cancellable: bool) -> &mut Self {
547        self.bytes.push(0x29);
548        self.bytes.push(if cancellable { 1 } else { 0 });
549        self.num_added += 1;
550        self
551    }
552
553    /// Declare a new `thread.resume-later` intrinsic, used to resume execution
554    /// of the given thread.
555    pub fn thread_resume_later(&mut self) -> &mut Self {
556        self.bytes.push(0x2a);
557        self.num_added += 1;
558        self
559    }
560
561    /// Declare a new `thread.yield-to` intrinsic, used to yield execution to
562    /// a given thread.
563    pub fn thread_yield_to(&mut self, cancellable: bool) -> &mut Self {
564        self.bytes.push(0x2b);
565        self.bytes.push(if cancellable { 1 } else { 0 });
566        self.num_added += 1;
567        self
568    }
569
570    fn encode_options<O>(&mut self, options: O) -> &mut Self
571    where
572        O: IntoIterator<Item = CanonicalOption>,
573        O::IntoIter: ExactSizeIterator,
574    {
575        let options = options.into_iter();
576        options.len().encode(&mut self.bytes);
577        for option in options {
578            option.encode(&mut self.bytes);
579        }
580        self
581    }
582}
583
584impl Encode for CanonicalFunctionSection {
585    fn encode(&self, sink: &mut Vec<u8>) {
586        encode_section(sink, self.num_added, &self.bytes);
587    }
588}
589
590impl ComponentSection for CanonicalFunctionSection {
591    fn id(&self) -> u8 {
592        ComponentSectionId::CanonicalFunction.into()
593    }
594}
wasm_encoder/component/canonicals.rs

wasm_encoder/component/
canonicals.rs
