wasm_encoder/component/
canonicals.rs

1use crate::{encode_section, ComponentSection, ComponentSectionId, ComponentValType, Encode};
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}
31
32impl Encode for CanonicalOption {
33    fn encode(&self, sink: &mut Vec<u8>) {
34        match self {
35            Self::UTF8 => sink.push(0x00),
36            Self::UTF16 => sink.push(0x01),
37            Self::CompactUTF16 => sink.push(0x02),
38            Self::Memory(idx) => {
39                sink.push(0x03);
40                idx.encode(sink);
41            }
42            Self::Realloc(idx) => {
43                sink.push(0x04);
44                idx.encode(sink);
45            }
46            Self::PostReturn(idx) => {
47                sink.push(0x05);
48                idx.encode(sink);
49            }
50            Self::Async => {
51                sink.push(0x06);
52            }
53            Self::Callback(idx) => {
54                sink.push(0x07);
55                idx.encode(sink);
56            }
57        }
58    }
59}
60
61/// An encoder for the canonical function section of WebAssembly components.
62///
63/// # Example
64///
65/// ```
66/// use wasm_encoder::{Component, CanonicalFunctionSection, CanonicalOption};
67///
68/// let mut functions = CanonicalFunctionSection::new();
69/// functions.lift(0, 0, [CanonicalOption::UTF8]);
70///
71/// let mut component = Component::new();
72/// component.section(&functions);
73///
74/// let bytes = component.finish();
75/// ```
76#[derive(Clone, Debug, Default)]
77pub struct CanonicalFunctionSection {
78    bytes: Vec<u8>,
79    num_added: u32,
80}
81
82impl CanonicalFunctionSection {
83    /// Construct a new component function section encoder.
84    pub fn new() -> Self {
85        Self::default()
86    }
87
88    /// The number of functions in the section.
89    pub fn len(&self) -> u32 {
90        self.num_added
91    }
92
93    /// Determines if the section is empty.
94    pub fn is_empty(&self) -> bool {
95        self.num_added == 0
96    }
97
98    /// Define a function that will lift a core WebAssembly function to the canonical ABI.
99    pub fn lift<O>(&mut self, core_func_index: u32, type_index: u32, options: O) -> &mut Self
100    where
101        O: IntoIterator<Item = CanonicalOption>,
102        O::IntoIter: ExactSizeIterator,
103    {
104        self.bytes.push(0x00);
105        self.bytes.push(0x00);
106        core_func_index.encode(&mut self.bytes);
107        self.encode_options(options);
108        type_index.encode(&mut self.bytes);
109        self.num_added += 1;
110        self
111    }
112
113    /// Define a function that will lower a canonical ABI function to a core WebAssembly function.
114    pub fn lower<O>(&mut self, func_index: u32, options: O) -> &mut Self
115    where
116        O: IntoIterator<Item = CanonicalOption>,
117        O::IntoIter: ExactSizeIterator,
118    {
119        self.bytes.push(0x01);
120        self.bytes.push(0x00);
121        func_index.encode(&mut self.bytes);
122        self.encode_options(options);
123        self.num_added += 1;
124        self
125    }
126
127    /// Defines a function which will create an owned handle to the resource
128    /// specified by `ty_index`.
129    pub fn resource_new(&mut self, ty_index: u32) -> &mut Self {
130        self.bytes.push(0x02);
131        ty_index.encode(&mut self.bytes);
132        self.num_added += 1;
133        self
134    }
135
136    /// Defines a function which will drop the specified type of handle.
137    pub fn resource_drop(&mut self, ty_index: u32) -> &mut Self {
138        self.bytes.push(0x03);
139        ty_index.encode(&mut self.bytes);
140        self.num_added += 1;
141        self
142    }
143
144    /// Defines a function which will drop the specified type of handle.
145    pub fn resource_drop_async(&mut self, ty_index: u32) -> &mut Self {
146        self.bytes.push(0x07);
147        ty_index.encode(&mut self.bytes);
148        self.num_added += 1;
149        self
150    }
151
152    /// Defines a function which will return the representation of the specified
153    /// resource type.
154    pub fn resource_rep(&mut self, ty_index: u32) -> &mut Self {
155        self.bytes.push(0x04);
156        ty_index.encode(&mut self.bytes);
157        self.num_added += 1;
158        self
159    }
160
161    /// Defines a function which will spawn a new thread by invoking a shared
162    /// function of type `ty_index`.
163    pub fn thread_spawn_ref(&mut self, ty_index: u32) -> &mut Self {
164        self.bytes.push(0x40);
165        ty_index.encode(&mut self.bytes);
166        self.num_added += 1;
167        self
168    }
169
170    /// Defines a function which will spawn a new thread by invoking a shared
171    /// function indirectly through a `funcref` table.
172    pub fn thread_spawn_indirect(&mut self, ty_index: u32, table_index: u32) -> &mut Self {
173        self.bytes.push(0x41);
174        ty_index.encode(&mut self.bytes);
175        table_index.encode(&mut self.bytes);
176        self.num_added += 1;
177        self
178    }
179
180    /// Defines a function which will return the number of threads that can be
181    /// expected to execute concurrently.
182    pub fn thread_available_parallelism(&mut self) -> &mut Self {
183        self.bytes.push(0x42);
184        self.num_added += 1;
185        self
186    }
187
188    /// Defines a function which tells the host to enable or disable
189    /// backpressure for the caller's instance.  When backpressure is enabled,
190    /// the host must not start any new calls to that instance until
191    /// backpressure is disabled.
192    pub fn backpressure_set(&mut self) -> &mut Self {
193        self.bytes.push(0x08);
194        self.num_added += 1;
195        self
196    }
197
198    /// Defines a function which returns a result to the caller of a lifted
199    /// export function.  This allows the callee to continue executing after
200    /// returning a result.
201    pub fn task_return<O>(&mut self, ty: Option<ComponentValType>, options: O) -> &mut Self
202    where
203        O: IntoIterator<Item = CanonicalOption>,
204        O::IntoIter: ExactSizeIterator,
205    {
206        self.bytes.push(0x09);
207        crate::encode_resultlist(&mut self.bytes, ty);
208        self.encode_options(options);
209        self.num_added += 1;
210        self
211    }
212
213    /// Defines a new `context.get` intrinsic of the ith slot.
214    pub fn context_get(&mut self, i: u32) -> &mut Self {
215        self.bytes.push(0x0a);
216        self.bytes.push(0x7f);
217        i.encode(&mut self.bytes);
218        self.num_added += 1;
219        self
220    }
221
222    /// Defines a new `context.set` intrinsic of the ith slot.
223    pub fn context_set(&mut self, i: u32) -> &mut Self {
224        self.bytes.push(0x0b);
225        self.bytes.push(0x7f);
226        i.encode(&mut self.bytes);
227        self.num_added += 1;
228        self
229    }
230
231    /// Defines a function which yields control to the host so that other tasks
232    /// are able to make progress, if any.
233    ///
234    /// If `async_` is true, the caller instance may be reentered.
235    pub fn yield_(&mut self, async_: bool) -> &mut Self {
236        self.bytes.push(0x0c);
237        self.bytes.push(if async_ { 1 } else { 0 });
238        self.num_added += 1;
239        self
240    }
241
242    /// Defines a function to drop a specified task which has completed.
243    pub fn subtask_drop(&mut self) -> &mut Self {
244        self.bytes.push(0x0d);
245        self.num_added += 1;
246        self
247    }
248
249    /// Defines a function to create a new `stream` handle of the specified
250    /// type.
251    pub fn stream_new(&mut self, ty: u32) -> &mut Self {
252        self.bytes.push(0x0e);
253        ty.encode(&mut self.bytes);
254        self.num_added += 1;
255        self
256    }
257
258    /// Defines a function to read from a `stream` of the specified type.
259    pub fn stream_read<O>(&mut self, ty: u32, options: O) -> &mut Self
260    where
261        O: IntoIterator<Item = CanonicalOption>,
262        O::IntoIter: ExactSizeIterator,
263    {
264        self.bytes.push(0x0f);
265        ty.encode(&mut self.bytes);
266        self.encode_options(options);
267        self.num_added += 1;
268        self
269    }
270
271    /// Defines a function to write to a `stream` of the specified type.
272    pub fn stream_write<O>(&mut self, ty: u32, options: O) -> &mut Self
273    where
274        O: IntoIterator<Item = CanonicalOption>,
275        O::IntoIter: ExactSizeIterator,
276    {
277        self.bytes.push(0x10);
278        ty.encode(&mut self.bytes);
279        self.encode_options(options);
280        self.num_added += 1;
281        self
282    }
283
284    /// Defines a function to cancel an in-progress read from a `stream` of the
285    /// specified type.
286    pub fn stream_cancel_read(&mut self, ty: u32, async_: bool) -> &mut Self {
287        self.bytes.push(0x11);
288        ty.encode(&mut self.bytes);
289        self.bytes.push(if async_ { 1 } else { 0 });
290        self.num_added += 1;
291        self
292    }
293
294    /// Defines a function to cancel an in-progress write to a `stream` of the
295    /// specified type.
296    pub fn stream_cancel_write(&mut self, ty: u32, async_: bool) -> &mut Self {
297        self.bytes.push(0x12);
298        ty.encode(&mut self.bytes);
299        self.bytes.push(if async_ { 1 } else { 0 });
300        self.num_added += 1;
301        self
302    }
303
304    /// Defines a function to close the readable end of a `stream` of the
305    /// specified type.
306    pub fn stream_close_readable(&mut self, ty: u32) -> &mut Self {
307        self.bytes.push(0x13);
308        ty.encode(&mut self.bytes);
309        self.num_added += 1;
310        self
311    }
312
313    /// Defines a function to close the writable end of a `stream` of the
314    /// specified type.
315    pub fn stream_close_writable(&mut self, ty: u32) -> &mut Self {
316        self.bytes.push(0x14);
317        ty.encode(&mut self.bytes);
318        self.num_added += 1;
319        self
320    }
321
322    /// Defines a function to create a new `future` handle of the specified
323    /// type.
324    pub fn future_new(&mut self, ty: u32) -> &mut Self {
325        self.bytes.push(0x15);
326        ty.encode(&mut self.bytes);
327        self.num_added += 1;
328        self
329    }
330
331    /// Defines a function to read from a `future` of the specified type.
332    pub fn future_read<O>(&mut self, ty: u32, options: O) -> &mut Self
333    where
334        O: IntoIterator<Item = CanonicalOption>,
335        O::IntoIter: ExactSizeIterator,
336    {
337        self.bytes.push(0x16);
338        ty.encode(&mut self.bytes);
339        self.encode_options(options);
340        self.num_added += 1;
341        self
342    }
343
344    /// Defines a function to write to a `future` of the specified type.
345    pub fn future_write<O>(&mut self, ty: u32, options: O) -> &mut Self
346    where
347        O: IntoIterator<Item = CanonicalOption>,
348        O::IntoIter: ExactSizeIterator,
349    {
350        self.bytes.push(0x17);
351        ty.encode(&mut self.bytes);
352        self.encode_options(options);
353        self.num_added += 1;
354        self
355    }
356
357    /// Defines a function to cancel an in-progress read from a `future` of the
358    /// specified type.
359    pub fn future_cancel_read(&mut self, ty: u32, async_: bool) -> &mut Self {
360        self.bytes.push(0x18);
361        ty.encode(&mut self.bytes);
362        self.bytes.push(if async_ { 1 } else { 0 });
363        self.num_added += 1;
364        self
365    }
366
367    /// Defines a function to cancel an in-progress write to a `future` of the
368    /// specified type.
369    pub fn future_cancel_write(&mut self, ty: u32, async_: bool) -> &mut Self {
370        self.bytes.push(0x19);
371        ty.encode(&mut self.bytes);
372        self.bytes.push(if async_ { 1 } else { 0 });
373        self.num_added += 1;
374        self
375    }
376
377    /// Defines a function to close the readable end of a `future` of the
378    /// specified type.
379    pub fn future_close_readable(&mut self, ty: u32) -> &mut Self {
380        self.bytes.push(0x1a);
381        ty.encode(&mut self.bytes);
382        self.num_added += 1;
383        self
384    }
385
386    /// Defines a function to close the writable end of a `future` of the
387    /// specified type.
388    pub fn future_close_writable(&mut self, ty: u32) -> &mut Self {
389        self.bytes.push(0x1b);
390        ty.encode(&mut self.bytes);
391        self.num_added += 1;
392        self
393    }
394
395    /// Defines a function to create a new `error-context` with a specified
396    /// debug message.
397    pub fn error_context_new<O>(&mut self, options: O) -> &mut Self
398    where
399        O: IntoIterator<Item = CanonicalOption>,
400        O::IntoIter: ExactSizeIterator,
401    {
402        self.bytes.push(0x1c);
403        self.encode_options(options);
404        self.num_added += 1;
405        self
406    }
407
408    /// Defines a function to get the debug message for a specified
409    /// `error-context`.
410    ///
411    /// Note that the debug message might not necessarily match what was passed
412    /// to `error-context.new`.
413    pub fn error_context_debug_message<O>(&mut self, options: O) -> &mut Self
414    where
415        O: IntoIterator<Item = CanonicalOption>,
416        O::IntoIter: ExactSizeIterator,
417    {
418        self.bytes.push(0x1d);
419        self.encode_options(options);
420        self.num_added += 1;
421        self
422    }
423
424    /// Defines a function to drop a specified `error-context`.
425    pub fn error_context_drop(&mut self) -> &mut Self {
426        self.bytes.push(0x1e);
427        self.num_added += 1;
428        self
429    }
430
431    /// Declare a new `waitable-set.new` intrinsic, used to create a
432    /// `waitable-set` pseudo-resource.
433    pub fn waitable_set_new(&mut self) -> &mut Self {
434        self.bytes.push(0x1f);
435        self.num_added += 1;
436        self
437    }
438
439    /// Declare a new `waitable-set.wait` intrinsic, used to block on a
440    /// `waitable-set`.
441    pub fn waitable_set_wait(&mut self, async_: bool, memory: u32) -> &mut Self {
442        self.bytes.push(0x20);
443        self.bytes.push(if async_ { 1 } else { 0 });
444        memory.encode(&mut self.bytes);
445        self.num_added += 1;
446        self
447    }
448
449    /// Declare a new `waitable-set.wait` intrinsic, used to check, without
450    /// blocking, if anything in a `waitable-set` is ready.
451    pub fn waitable_set_poll(&mut self, async_: bool, memory: u32) -> &mut Self {
452        self.bytes.push(0x21);
453        self.bytes.push(if async_ { 1 } else { 0 });
454        memory.encode(&mut self.bytes);
455        self.num_added += 1;
456        self
457    }
458
459    /// Declare a new `waitable-set.drop` intrinsic, used to dispose a
460    /// `waitable-set` pseudo-resource.
461    pub fn waitable_set_drop(&mut self) -> &mut Self {
462        self.bytes.push(0x22);
463        self.num_added += 1;
464        self
465    }
466
467    /// Declare a new `waitable.join` intrinsic, used to add an item to a
468    /// `waitable-set`.
469    pub fn waitable_join(&mut self) -> &mut Self {
470        self.bytes.push(0x23);
471        self.num_added += 1;
472        self
473    }
474
475    fn encode_options<O>(&mut self, options: O) -> &mut Self
476    where
477        O: IntoIterator<Item = CanonicalOption>,
478        O::IntoIter: ExactSizeIterator,
479    {
480        let options = options.into_iter();
481        options.len().encode(&mut self.bytes);
482        for option in options {
483            option.encode(&mut self.bytes);
484        }
485        self
486    }
487}
488
489impl Encode for CanonicalFunctionSection {
490    fn encode(&self, sink: &mut Vec<u8>) {
491        encode_section(sink, self.num_added, &self.bytes);
492    }
493}
494
495impl ComponentSection for CanonicalFunctionSection {
496    fn id(&self) -> u8 {
497        ComponentSectionId::CanonicalFunction.into()
498    }
499}
wasm_encoder/component/canonicals.rs

wasm_encoder/component/
canonicals.rs
