witnext 0.10.0-beta3

witx parser for the witx-codegen webassembly code generator
Documentation
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
(assert_abi
  (witx (module $x (@interface func (export "f"))))
  (wasm)
  (declared_import call.wasm return)
  (defined_import call.interface return)
)

;; scalar arguments
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p u8))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_u8 arg0 call.wasm return)
  (defined_import get-arg0 u8.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p s8))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_s8 arg0 call.wasm return)
  (defined_import get-arg0 s8.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p u16))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_u16 arg0 call.wasm return)
  (defined_import get-arg0 u16.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p s16))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_s16 arg0 call.wasm return)
  (defined_import get-arg0 s16.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p u32))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_u32 arg0 call.wasm return)
  (defined_import get-arg0 u32.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p s32))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_s32 arg0 call.wasm return)
  (defined_import get-arg0 s32.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p u64))))
  (wasm (param i64))
  (declared_import get-arg0 i64.from_u64 arg0 call.wasm return)
  (defined_import get-arg0 u64.from_i64 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p s64))))
  (wasm (param i64))
  (declared_import get-arg0 i64.from_s64 arg0 call.wasm return)
  (defined_import get-arg0 s64.from_i64 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p f32))))
  (wasm (param f32))
  (declared_import get-arg0 f32.from_if32 arg0 call.wasm return)
  (defined_import get-arg0 if32.from_f32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p f64))))
  (wasm (param f64))
  (declared_import get-arg0 f64.from_if64 arg0 call.wasm return)
  (defined_import get-arg0 if64.from_f64 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p (@witx usize)))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_usize arg0 call.wasm return)
  (defined_import get-arg0 usize.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p (@witx char8)))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_char8 arg0 call.wasm return)
  (defined_import get-arg0 char8.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p char))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_char arg0 call.wasm return)
  (defined_import get-arg0 char.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p (@witx pointer u8)))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_pointer arg0 call.wasm return)
  (defined_import get-arg0 pointer.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (param $p (@witx const_pointer u8)))))
  (wasm (param i32))
  (declared_import get-arg0 i32.from_const_pointer arg0 call.wasm return)
  (defined_import get-arg0 const_pointer.from_i32 arg0 call.interface return)
)

;; flags parameter
(assert_abi
  (witx
    (module $x
      (typename $a (flags $x $y))
      (@interface func (export "f") (param $p $a))
    )
  )
  (wasm (param i32))
  (declared_import get-arg0 i32.from_bitflags arg0 call.wasm return)
  (defined_import get-arg0 bitflags.from_i32 arg0 call.interface return)
)
(assert_abi
  (witx
    (module $x
      (typename $a (flags (@witx repr u64) $x $y))
      (@interface func (export "f") (param $p $a))
    )
  )
  (wasm (param i64))
  (declared_import get-arg0 i64.from_bitflags arg0 call.wasm return)
  (defined_import get-arg0 bitflags.from_i64 arg0 call.interface return)
)
(assert_abi
  (witx
    (module $x
      (typename $a (record (field $x bool)))
      (@interface func (export "f") (param $p $a))
    )
  )
  (wasm (param i32))
  (declared_import get-arg0 i32.from_bitflags arg0 call.wasm return)
)

;; struct parameter
(assert_abi
  (witx
    (module $x
      (typename $a (record (field $x u8)))
      (@interface func (export "f") (param $p $a))
    )
  )
  (wasm (param i32))
  (declared_import get-arg0 addr-of arg0 call.wasm return)
  (defined_import
    get-arg0
    i32.load8u offset=0 arg0
    u8.from_i32
    record-lift
    call.interface
    return)
)

;; handle parameter
(assert_abi
  (witx
    (module $x
      (resource $a)
      (typename $a (handle $a))
      (@interface func (export "f") (param $p $a))
    )
  )
  (wasm (param i32))
  (declared_import get-arg0 i32.from_borrowed_handle arg0 call.wasm return)
  (defined_import get-arg0 handle.borrowed_from_i32 arg0 call.interface return)
)

;; list parameter
(assert_abi
  (witx
    (module $x
      (@interface func (export "f") (param $p (list u8))))
  )
  (wasm (param i32 i32))
  (declared_import get-arg0 list.canon_lower arg0 call.wasm return)
  (defined_import
    get-arg0
    get-arg1
    list.canon_lift arg0 arg1
    call.interface
    return)
)

;; variant parameter -- some not allowed at this time
(assert_abi
  (witx
    (module $x
      (typename $a (enum $b))
      (@interface func (export "f") (param $p $a))
    )
  )
  (wasm (param i32))
  (declared_import
    get-arg0
    block.push
      i32.const 0
    block.finish
    variant-lower arg0
    call.wasm
    return)
  (defined_import
    get-arg0
    block.push
    block.finish
    variant-lift arg0
    call.interface
    return)
)
(assert_abi
  (witx
    (module $x
      (typename $a (union f32))
      (@interface func (export "f") (param $p $a))
    )
  )
  (wasm (param i32))
  (declared_import get-arg0 addr-of arg0 call.wasm return)
  (defined_import
    get-arg0
    i32.load8u offset=0 arg0
    block.push
      f32.load offset=4 arg0
      if32.from_f32
    block.finish
    variant-lift
    call.interface
    return)
)

;; scalar returns
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p u8))))
  (wasm (result i32))
  (declared_import call.wasm u8.from_i32 ret0 return)
  (defined_import call.interface i32.from_u8 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p s8))))
  (wasm (result i32))
  (declared_import call.wasm s8.from_i32 ret0 return)
  (defined_import call.interface i32.from_s8 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p u16))))
  (wasm (result i32))
  (declared_import call.wasm u16.from_i32 ret0 return)
  (defined_import call.interface i32.from_u16 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p s16))))
  (wasm (result i32))
  (declared_import call.wasm s16.from_i32 ret0 return)
  (defined_import call.interface i32.from_s16 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p u32))))
  (wasm (result i32))
  (declared_import call.wasm u32.from_i32 ret0 return)
  (defined_import call.interface i32.from_u32 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p s32))))
  (wasm (result i32))
  (declared_import call.wasm s32.from_i32 ret0 return)
  (defined_import call.interface i32.from_s32 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p u64))))
  (wasm (result i64))
  (declared_import call.wasm u64.from_i64 ret0 return)
  (defined_import call.interface i64.from_u64 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p s64))))
  (wasm (result i64))
  (declared_import call.wasm s64.from_i64 ret0 return)
  (defined_import call.interface i64.from_s64 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p f32))))
  (wasm (result f32))
  (declared_import call.wasm if32.from_f32 ret0 return)
  (defined_import call.interface f32.from_if32 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p f64))))
  (wasm (result f64))
  (declared_import call.wasm if64.from_f64 ret0 return)
  (defined_import call.interface f64.from_if64 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p (@witx usize)))))
  (wasm (result i32))
  (declared_import call.wasm usize.from_i32 ret0 return)
  (defined_import call.interface i32.from_usize ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p (@witx char8)))))
  (wasm (result i32))
  (declared_import call.wasm char8.from_i32 ret0 return)
  (defined_import call.interface i32.from_char8 ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p char))))
  (wasm (result i32))
  (declared_import call.wasm char.from_i32 ret0 return)
  (defined_import call.interface i32.from_char ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p (@witx pointer u8)))))
  (wasm (result i32))
  (declared_import call.wasm pointer.from_i32 ret0 return)
  (defined_import call.interface i32.from_pointer ret0 return)
)
(assert_abi
  (witx (module $x (@interface func (export "f") (result $p (@witx const_pointer u8)))))
  (wasm (result i32))
  (declared_import call.wasm const_pointer.from_i32 ret0 return)
  (defined_import call.interface i32.from_const_pointer ret0 return)
)

;; flags ret0 return
(assert_abi
  (witx
    (module $x
      (typename $a (flags $x $y))
      (@interface func (export "f") (result $p $a))
    )
  )
  (wasm (result i32))
  (declared_import call.wasm bitflags.from_i32 ret0 return)
  (defined_import call.interface i32.from_bitflags ret0 return)
)
(assert_abi
  (witx
    (module $x
      (typename $a (flags (@witx repr u64) $x $y))
      (@interface func (export "f") (result $p $a))
    )
  )
  (wasm (result i64))
  (declared_import call.wasm bitflags.from_i64 ret0 return)
  (defined_import call.interface i64.from_bitflags ret0 return)
)

;; handle ret0 return
(assert_abi
  (witx
    (module $x
      (resource $a)
      (typename $a (handle $a))
      (@interface func (export "f") (result $p $a))
    )
  )
  (wasm (result i32))
  (declared_import call.wasm handle.owned_from_i32 ret0 return)
  (defined_import call.interface i32.from_owned_handle ret0 return)
)

;; struct return -- not supported
(assert_invalid
  (witx
    (module $x
      (typename $a (record (field $x u8)))
      (@interface func (export "f") (result $p $a))
    )
  )
  "ABI error: invalid return type"
)

;; list return -- not supported
(assert_invalid
  (witx
    (module $x (@interface func (export "f") (result $p (list u8))))
  )
  "ABI error: invalid return type"
)

;; variant return -- only some allowed
(assert_invalid
  (witx
    (module $x
      (typename $a (enum $b))
      (@interface func (export "f") (result $p $a))
    )
  )
  "ABI error: invalid return type"
)
(assert_invalid
  (witx
    (module $x
      (typename $a (union s32 f32))
      (@interface func (export "f") (result $p $a))
    )
  )
  "ABI error: invalid return type"
)
(assert_invalid
  (witx
    (module $x
      (typename $a (expected (error f32)))
      (@interface func (export "f") (result $p $a))
    )
  )
  "ABI error: only named types are allowed in results"
)
(assert_invalid
  (witx
    (module $x
      (typename $errno (enum $success $bad))
      (typename $a (expected f32 (error $errno)))
      (@interface func (export "f") (result $p $a))
    )
  )
  "ABI error: only named types are allowed in results"
)

;; Result<(), $errno>
(assert_abi
  (witx
    (module $x
      (typename $errno (enum $success $bad))
      (typename $a (expected (error $errno)))
      (@interface func (export "f") (result $p $a))
    )
  )
  (wasm (result i32))

  (declared_import
    call.wasm
    ;; ok block, nothing happens
    block.push
    block.finish
    ;; err block, we lift the return value as the num
    block.push
      reuse_return
      block.push
      block.finish
      block.push
      block.finish
      variant-lift
    block.finish
    ;; consumes 2 blocks and uses the return value of the call to discriminate
    variant-lift ret0
    return)

  (defined_import
    call.interface

    ;; ok block, nothing happens
    block.push
      i32.const 0
    block.finish

    ;; err block, lift the enum
    block.push
      variant-payload
      block.push
        i32.const 0
      block.finish
      block.push
        i32.const 1
      block.finish
      variant-lower
    block.finish

    ;; consume the 2 blocks and lower based on the call
    variant-lower ret0
    return)
)

;; Result<$ty, $errno>
(assert_abi
  (witx
    (module $x
      (typename $errno (enum $success $bad))
      (typename $size u32)
      (typename $a (expected $size (error $errno)))
      (@interface func (export "f") (result $p $a))
    )
  )
  (wasm (param i32) (result i32))

  (declared_import
    call.wasm rp0

    ;; ok block, load the return pointer and have it be the result for the `Ok`
    block.push
      i32.load offset=0 rp0
      u32.from_i32
    block.finish

    block.push
      reuse_return
      block.push
      block.finish
      block.push
      block.finish
      variant-lift
    block.finish

    variant-lift ret0
    return)

  (defined_import
    call.interface

    ;; store the successful result at the first return pointer (the first param)
    block.push
      variant-payload
      get-arg0
      i32.from_u32
      i32.store offset=0 arg0
      i32.const 0
    block.finish

    block.push
      variant-payload
      block.push
        i32.const 0
      block.finish
      block.push
        i32.const 1
      block.finish
      variant-lower
    block.finish

    variant-lower ret0
    return)
)

;; Result<($a, $b), $errno>
(assert_abi
  (witx
    (module $x
      (typename $errno (enum $success $bad))
      (typename $size u32)
      (typename $other (record (field $a $size)))
      (@interface func (export "f")
        (result $p (expected (tuple $size $other) (error $errno))))
    )
  )
  (wasm (param i32 i32) (result i32))

  (declared_import
    call.wasm rp0 rp1

    block.push
      i32.load offset=0 rp0
      u32.from_i32
      i32.load offset=0 rp1
      u32.from_i32
      record-lift
      record-lift
    block.finish

    block.push
      reuse_return
      block.push
      block.finish
      block.push
      block.finish
      variant-lift
    block.finish

    variant-lift ret0
    return)

  (defined_import
    call.interface

    ;; note the reverse order since we're consuming the results of lowering the
    ;; tuple
    block.push
      variant-payload
      record-lower
      get-arg1
      record-lower field.1
      i32.from_u32 field.a
      i32.store offset=0 arg1
      get-arg0
      i32.from_u32 field.0
      i32.store offset=0 arg0
      i32.const 0
    block.finish

    block.push
      variant-payload
      block.push
        i32.const 0
      block.finish
      block.push
        i32.const 1
      block.finish
      variant-lower
    block.finish

    variant-lower ret0
    return)
)