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 spawns a new thread by invoking a shared
162    /// function of type `ty_index`.
163    pub fn thread_spawn(&mut self, ty_index: u32) -> &mut Self {
164        self.bytes.push(0x05);
165        ty_index.encode(&mut self.bytes);
166        self.num_added += 1;
167        self
168    }
169
170    /// Defines a function which will return the number of threads that can be
171    /// expected to execute concurrently.
172    pub fn thread_available_parallelism(&mut self) -> &mut Self {
173        self.bytes.push(0x06);
174        self.num_added += 1;
175        self
176    }
177
178    /// Defines a function which tells the host to enable or disable
179    /// backpressure for the caller's instance.  When backpressure is enabled,
180    /// the host must not start any new calls to that instance until
181    /// backpressure is disabled.
182    pub fn backpressure_set(&mut self) -> &mut Self {
183        self.bytes.push(0x08);
184        self.num_added += 1;
185        self
186    }
187
188    /// Defines a function which returns a result to the caller of a lifted
189    /// export function.  This allows the callee to continue executing after
190    /// returning a result.
191    pub fn task_return<O>(&mut self, ty: Option<ComponentValType>, options: O) -> &mut Self
192    where
193        O: IntoIterator<Item = CanonicalOption>,
194        O::IntoIter: ExactSizeIterator,
195    {
196        self.bytes.push(0x09);
197        crate::encode_resultlist(&mut self.bytes, ty);
198        self.encode_options(options);
199        self.num_added += 1;
200        self
201    }
202
203    /// Defines a function which yields control to the host so that other tasks
204    /// are able to make progress, if any.
205    ///
206    /// If `async_` is true, the caller instance may be reentered.
207    pub fn yield_(&mut self, async_: bool) -> &mut Self {
208        self.bytes.push(0x0c);
209        self.bytes.push(if async_ { 1 } else { 0 });
210        self.num_added += 1;
211        self
212    }
213
214    /// Defines a function to drop a specified task which has completed.
215    pub fn subtask_drop(&mut self) -> &mut Self {
216        self.bytes.push(0x0d);
217        self.num_added += 1;
218        self
219    }
220
221    /// Defines a function to create a new `stream` handle of the specified
222    /// type.
223    pub fn stream_new(&mut self, ty: u32) -> &mut Self {
224        self.bytes.push(0x0e);
225        ty.encode(&mut self.bytes);
226        self.num_added += 1;
227        self
228    }
229
230    /// Defines a function to read from a `stream` of the specified type.
231    pub fn stream_read<O>(&mut self, ty: u32, options: O) -> &mut Self
232    where
233        O: IntoIterator<Item = CanonicalOption>,
234        O::IntoIter: ExactSizeIterator,
235    {
236        self.bytes.push(0x0f);
237        ty.encode(&mut self.bytes);
238        self.encode_options(options);
239        self.num_added += 1;
240        self
241    }
242
243    /// Defines a function to write to a `stream` of the specified type.
244    pub fn stream_write<O>(&mut self, ty: u32, options: O) -> &mut Self
245    where
246        O: IntoIterator<Item = CanonicalOption>,
247        O::IntoIter: ExactSizeIterator,
248    {
249        self.bytes.push(0x10);
250        ty.encode(&mut self.bytes);
251        self.encode_options(options);
252        self.num_added += 1;
253        self
254    }
255
256    /// Defines a function to cancel an in-progress read from a `stream` of the
257    /// specified type.
258    pub fn stream_cancel_read(&mut self, ty: u32, async_: bool) -> &mut Self {
259        self.bytes.push(0x11);
260        ty.encode(&mut self.bytes);
261        self.bytes.push(if async_ { 1 } else { 0 });
262        self.num_added += 1;
263        self
264    }
265
266    /// Defines a function to cancel an in-progress write to a `stream` of the
267    /// specified type.
268    pub fn stream_cancel_write(&mut self, ty: u32, async_: bool) -> &mut Self {
269        self.bytes.push(0x12);
270        ty.encode(&mut self.bytes);
271        self.bytes.push(if async_ { 1 } else { 0 });
272        self.num_added += 1;
273        self
274    }
275
276    /// Defines a function to close the readable end of a `stream` of the
277    /// specified type.
278    pub fn stream_close_readable(&mut self, ty: u32) -> &mut Self {
279        self.bytes.push(0x13);
280        ty.encode(&mut self.bytes);
281        self.num_added += 1;
282        self
283    }
284
285    /// Defines a function to close the writable end of a `stream` of the
286    /// specified type.
287    pub fn stream_close_writable(&mut self, ty: u32) -> &mut Self {
288        self.bytes.push(0x14);
289        ty.encode(&mut self.bytes);
290        self.num_added += 1;
291        self
292    }
293
294    /// Defines a function to create a new `future` handle of the specified
295    /// type.
296    pub fn future_new(&mut self, ty: u32) -> &mut Self {
297        self.bytes.push(0x15);
298        ty.encode(&mut self.bytes);
299        self.num_added += 1;
300        self
301    }
302
303    /// Defines a function to read from a `future` of the specified type.
304    pub fn future_read<O>(&mut self, ty: u32, options: O) -> &mut Self
305    where
306        O: IntoIterator<Item = CanonicalOption>,
307        O::IntoIter: ExactSizeIterator,
308    {
309        self.bytes.push(0x16);
310        ty.encode(&mut self.bytes);
311        self.encode_options(options);
312        self.num_added += 1;
313        self
314    }
315
316    /// Defines a function to write to a `future` of the specified type.
317    pub fn future_write<O>(&mut self, ty: u32, options: O) -> &mut Self
318    where
319        O: IntoIterator<Item = CanonicalOption>,
320        O::IntoIter: ExactSizeIterator,
321    {
322        self.bytes.push(0x17);
323        ty.encode(&mut self.bytes);
324        self.encode_options(options);
325        self.num_added += 1;
326        self
327    }
328
329    /// Defines a function to cancel an in-progress read from a `future` of the
330    /// specified type.
331    pub fn future_cancel_read(&mut self, ty: u32, async_: bool) -> &mut Self {
332        self.bytes.push(0x18);
333        ty.encode(&mut self.bytes);
334        self.bytes.push(if async_ { 1 } else { 0 });
335        self.num_added += 1;
336        self
337    }
338
339    /// Defines a function to cancel an in-progress write to a `future` of the
340    /// specified type.
341    pub fn future_cancel_write(&mut self, ty: u32, async_: bool) -> &mut Self {
342        self.bytes.push(0x19);
343        ty.encode(&mut self.bytes);
344        self.bytes.push(if async_ { 1 } else { 0 });
345        self.num_added += 1;
346        self
347    }
348
349    /// Defines a function to close the readable end of a `future` of the
350    /// specified type.
351    pub fn future_close_readable(&mut self, ty: u32) -> &mut Self {
352        self.bytes.push(0x1a);
353        ty.encode(&mut self.bytes);
354        self.num_added += 1;
355        self
356    }
357
358    /// Defines a function to close the writable end of a `future` of the
359    /// specified type.
360    pub fn future_close_writable(&mut self, ty: u32) -> &mut Self {
361        self.bytes.push(0x1b);
362        ty.encode(&mut self.bytes);
363        self.num_added += 1;
364        self
365    }
366
367    /// Defines a function to create a new `error-context` with a specified
368    /// debug message.
369    pub fn error_context_new<O>(&mut self, options: O) -> &mut Self
370    where
371        O: IntoIterator<Item = CanonicalOption>,
372        O::IntoIter: ExactSizeIterator,
373    {
374        self.bytes.push(0x1c);
375        self.encode_options(options);
376        self.num_added += 1;
377        self
378    }
379
380    /// Defines a function to get the debug message for a specified
381    /// `error-context`.
382    ///
383    /// Note that the debug message might not necessarily match what was passed
384    /// to `error-context.new`.
385    pub fn error_context_debug_message<O>(&mut self, options: O) -> &mut Self
386    where
387        O: IntoIterator<Item = CanonicalOption>,
388        O::IntoIter: ExactSizeIterator,
389    {
390        self.bytes.push(0x1d);
391        self.encode_options(options);
392        self.num_added += 1;
393        self
394    }
395
396    /// Defines a function to drop a specified `error-context`.
397    pub fn error_context_drop(&mut self) -> &mut Self {
398        self.bytes.push(0x1e);
399        self.num_added += 1;
400        self
401    }
402
403    /// Declare a new `waitable-set.new` intrinsic, used to create a
404    /// `waitable-set` pseudo-resource.
405    pub fn waitable_set_new(&mut self) -> &mut Self {
406        self.bytes.push(0x1f);
407        self.num_added += 1;
408        self
409    }
410
411    /// Declare a new `waitable-set.wait` intrinsic, used to block on a
412    /// `waitable-set`.
413    pub fn waitable_set_wait(&mut self, async_: bool, memory: u32) -> &mut Self {
414        self.bytes.push(0x20);
415        self.bytes.push(if async_ { 1 } else { 0 });
416        memory.encode(&mut self.bytes);
417        self.num_added += 1;
418        self
419    }
420
421    /// Declare a new `waitable-set.wait` intrinsic, used to check, without
422    /// blocking, if anything in a `waitable-set` is ready.
423    pub fn waitable_set_poll(&mut self, async_: bool, memory: u32) -> &mut Self {
424        self.bytes.push(0x21);
425        self.bytes.push(if async_ { 1 } else { 0 });
426        memory.encode(&mut self.bytes);
427        self.num_added += 1;
428        self
429    }
430
431    /// Declare a new `waitable-set.drop` intrinsic, used to dispose a
432    /// `waitable-set` pseudo-resource.
433    pub fn waitable_set_drop(&mut self) -> &mut Self {
434        self.bytes.push(0x22);
435        self.num_added += 1;
436        self
437    }
438
439    /// Declare a new `waitable.join` intrinsic, used to add an item to a
440    /// `waitable-set`.
441    pub fn waitable_join(&mut self) -> &mut Self {
442        self.bytes.push(0x23);
443        self.num_added += 1;
444        self
445    }
446
447    fn encode_options<O>(&mut self, options: O) -> &mut Self
448    where
449        O: IntoIterator<Item = CanonicalOption>,
450        O::IntoIter: ExactSizeIterator,
451    {
452        let options = options.into_iter();
453        options.len().encode(&mut self.bytes);
454        for option in options {
455            option.encode(&mut self.bytes);
456        }
457        self
458    }
459}
460
461impl Encode for CanonicalFunctionSection {
462    fn encode(&self, sink: &mut Vec<u8>) {
463        encode_section(sink, self.num_added, &self.bytes);
464    }
465}
466
467impl ComponentSection for CanonicalFunctionSection {
468    fn id(&self) -> u8 {
469        ComponentSectionId::CanonicalFunction.into()
470    }
471}
wasm_encoder/component/canonicals.rs

wasm_encoder/component/
canonicals.rs
