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
use anyhow::{Context, Result};
use id_arena::{Arena, Id};
use indexmap::IndexMap;
use semver::Version;
use serde_derive::Serialize;
use std::borrow::Cow;
use std::fmt;
use std::path::Path;

pub mod abi;
mod ast;
use ast::lex::Span;
pub use ast::SourceMap;
mod sizealign;
pub use sizealign::*;
mod resolve;
pub use resolve::{Package, PackageId, Remap, Resolve};
mod live;
pub use live::LiveTypes;
mod serde_;
use serde_::{
    serialize_anon_result, serialize_id, serialize_id_map, serialize_none, serialize_optional_id,
    serialize_params,
};

/// Checks if the given string is a legal identifier in wit.
pub fn validate_id(s: &str) -> Result<()> {
    ast::validate_id(0, s)?;
    Ok(())
}

pub type WorldId = Id<World>;
pub type InterfaceId = Id<Interface>;
pub type TypeId = Id<TypeDef>;

/// Representation of a parsed WIT package which has not resolved external
/// dependencies yet.
///
/// This representation has performed internal resolution of the WIT package
/// itself, ensuring that all references internally are valid and the WIT was
/// syntactically valid and such.
///
/// The fields of this structure represent a flat list of arrays unioned from
/// all documents within the WIT package. This means, for example, that all
/// types from all documents are located in `self.types`. The fields of each
/// item can help splitting back out into packages/interfaces/etc as necessary.
///
/// Note that an `UnresolvedPackage` cannot be queried in general about
/// information such as size or alignment as that would require resolution of
/// foreign dependencies. Translations such as to-binary additionally are not
/// supported on an `UnresolvedPackage` due to the lack of knowledge about the
/// foreign types. This is intended to be an intermediate state which can be
/// inspected by embedders, if necessary, before quickly transforming to a
/// [`Resolve`] to fully work with a WIT package.
///
/// After an [`UnresolvedPackage`] is parsed it can be fully resolved with
/// [`Resolve::push`]. During this operation a dependency map is specified which
/// will connect the `foreign_deps` field of this structure to packages
/// previously inserted within the [`Resolve`]. Embedders are responsible for
/// performing this resolution themselves.
#[derive(Clone)]
pub struct UnresolvedPackage {
    /// The namespace, name, and version information for this package.
    pub name: PackageName,

    /// All worlds from all documents within this package.
    ///
    /// Each world lists the document that it is from.
    pub worlds: Arena<World>,

    /// All interfaces from all documents within this package.
    ///
    /// Each interface lists the document that it is from. Interfaces are listed
    /// in topological order as well so iteration through this arena will only
    /// reference prior elements already visited when working with recursive
    /// references.
    pub interfaces: Arena<Interface>,

    /// All types from all documents within this package.
    ///
    /// Each type lists the interface or world that defined it, or nothing if
    /// it's an anonymous type. Types are listed in this arena in topological
    /// order to ensure that iteration through this arena will only reference
    /// other types transitively that are already iterated over.
    pub types: Arena<TypeDef>,

    /// All foreign dependencies that this package depends on.
    ///
    /// These foreign dependencies must be resolved to convert this unresolved
    /// package into a `Resolve`. The map here is keyed by the name of the
    /// foreign package that this depends on, and the sub-map is keyed by an
    /// interface name followed by the identifier within `self.interfaces`. The
    /// fields of `self.interfaces` describes the required types that are from
    /// each foreign interface.
    pub foreign_deps: IndexMap<PackageName, IndexMap<String, AstItem>>,

    /// Doc comments for this package.
    pub docs: Docs,

    unknown_type_spans: Vec<Span>,
    world_item_spans: Vec<(Vec<Span>, Vec<Span>)>,
    interface_spans: Vec<Span>,
    world_spans: Vec<Span>,
    foreign_dep_spans: Vec<Span>,
    source_map: SourceMap,
    include_world_spans: Vec<Span>,
    required_resource_types: Vec<(TypeId, Span)>,
}

#[derive(Debug, Copy, Clone, Serialize)]
#[serde(rename_all = "lowercase")]
pub enum AstItem {
    #[serde(serialize_with = "serialize_id")]
    Interface(InterfaceId),
    #[serde(serialize_with = "serialize_id")]
    World(WorldId),
}

/// A structure used to keep track of the name of a package, containing optional
/// information such as a namespace and version information.
///
/// This is directly encoded as an "ID" in the binary component representation
/// with an interfaced tacked on as well.
#[derive(Debug, Clone, Hash, Eq, PartialEq, Ord, PartialOrd, Serialize)]
#[serde(into = "String")]
pub struct PackageName {
    /// A namespace such as `wasi` in `wasi:foo/bar`
    pub namespace: String,
    /// The kebab-name of this package, which is always specified.
    pub name: String,
    /// Optional major/minor version information.
    pub version: Option<Version>,
}

impl From<PackageName> for String {
    fn from(name: PackageName) -> String {
        name.to_string()
    }
}

impl PackageName {
    /// Returns the ID that this package name would assign the `interface` name
    /// specified.
    pub fn interface_id(&self, interface: &str) -> String {
        let mut s = String::new();
        s.push_str(&format!("{}:{}/{interface}", self.namespace, self.name));
        if let Some(version) = &self.version {
            s.push_str(&format!("@{version}"));
        }
        s
    }
}

impl fmt::Display for PackageName {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}:{}", self.namespace, self.name)?;
        if let Some(version) = &self.version {
            write!(f, "@{version}")?;
        }
        Ok(())
    }
}

#[derive(Debug)]
struct Error {
    span: Span,
    msg: String,
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.msg.fmt(f)
    }
}

impl std::error::Error for Error {}

impl UnresolvedPackage {
    /// Parses the given string as a wit document.
    ///
    /// The `path` argument is used for error reporting. The `contents` provided
    /// will not be able to use `pkg` use paths to other documents.
    pub fn parse(path: &Path, contents: &str) -> Result<Self> {
        let mut map = SourceMap::default();
        map.push(path, contents);
        map.parse()
    }

    /// Parse a WIT package at the provided path.
    ///
    /// The path provided is inferred whether it's a file or a directory. A file
    /// is parsed with [`UnresolvedPackage::parse_file`] and a directory is
    /// parsed with [`UnresolvedPackage::parse_dir`].
    pub fn parse_path(path: &Path) -> Result<Self> {
        if path.is_dir() {
            UnresolvedPackage::parse_dir(path)
        } else {
            UnresolvedPackage::parse_file(path)
        }
    }

    /// Parses a WIT package from the file provided.
    ///
    /// The WIT package returned will be a single-document package and will not
    /// be able to use `pkg` paths to other documents.
    pub fn parse_file(path: &Path) -> Result<Self> {
        let contents = std::fs::read_to_string(path)
            .with_context(|| format!("failed to read file {path:?}"))?;
        Self::parse(path, &contents)
    }

    /// Parses a WIT package from the directory provided.
    ///
    /// All files with the extension `*.wit` or `*.wit.md` will be loaded from
    /// `path` into the returned package.
    pub fn parse_dir(path: &Path) -> Result<Self> {
        let mut map = SourceMap::default();
        let cx = || format!("failed to read directory {path:?}");
        for entry in path.read_dir().with_context(&cx)? {
            let entry = entry.with_context(&cx)?;
            let path = entry.path();
            let ty = entry.file_type().with_context(&cx)?;
            if ty.is_dir() {
                continue;
            }
            if ty.is_symlink() {
                if path.is_dir() {
                    continue;
                }
            }
            let filename = match path.file_name().and_then(|s| s.to_str()) {
                Some(name) => name,
                None => continue,
            };
            if !filename.ends_with(".wit") && !filename.ends_with(".wit.md") {
                continue;
            }
            map.push_file(&path)?;
        }
        map.parse()
    }

    /// Returns an iterator over the list of source files that were read when
    /// parsing this package.
    pub fn source_files(&self) -> impl Iterator<Item = &Path> {
        self.source_map.source_files()
    }
}

#[derive(Debug, Clone, Serialize)]
pub struct World {
    /// The WIT identifier name of this world.
    pub name: String,

    /// All imported items into this interface, both worlds and functions.
    pub imports: IndexMap<WorldKey, WorldItem>,

    /// All exported items from this interface, both worlds and functions.
    pub exports: IndexMap<WorldKey, WorldItem>,

    /// The package that owns this world.
    #[serde(serialize_with = "serialize_optional_id")]
    pub package: Option<PackageId>,

    /// Documentation associated with this world declaration.
    #[serde(skip_serializing_if = "Docs::is_empty")]
    pub docs: Docs,

    /// All the included worlds from this world. Empty if this is fully resolved
    #[serde(skip)]
    pub includes: Vec<WorldId>,

    /// All the included worlds names. Empty if this is fully resolved
    #[serde(skip)]
    pub include_names: Vec<Vec<IncludeName>>,
}

#[derive(Debug, Clone)]
pub struct IncludeName {
    /// The name of the item
    pub name: String,

    /// The name to be replaced with
    pub as_: String,
}

/// The key to the import/export maps of a world. Either a kebab-name or a
/// unique interface.
#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
#[serde(into = "String")]
pub enum WorldKey {
    /// A kebab-name.
    Name(String),
    /// An interface which is assigned no kebab-name.
    Interface(InterfaceId),
}

impl From<WorldKey> for String {
    fn from(key: WorldKey) -> String {
        match key {
            WorldKey::Name(name) => name,
            WorldKey::Interface(id) => format!("interface-{}", id.index()),
        }
    }
}

impl WorldKey {
    /// Asserts that this is `WorldKey::Name` and returns the name.
    #[track_caller]
    pub fn unwrap_name(self) -> String {
        match self {
            WorldKey::Name(name) => name,
            WorldKey::Interface(_) => panic!("expected a name, found interface"),
        }
    }
}

#[derive(Debug, Clone, PartialEq, Serialize)]
#[serde(rename_all = "lowercase")]
pub enum WorldItem {
    /// An interface is being imported or exported from a world, indicating that
    /// it's a namespace of functions.
    #[serde(serialize_with = "serialize_id")]
    Interface(InterfaceId),

    /// A function is being directly imported or exported from this world.
    Function(Function),

    /// A type is being exported from this world.
    ///
    /// Note that types are never imported into worlds at this time.
    #[serde(serialize_with = "serialize_id")]
    Type(TypeId),
}

#[derive(Debug, Clone, Serialize)]
pub struct Interface {
    /// Optionally listed name of this interface.
    ///
    /// This is `None` for inline interfaces in worlds.
    pub name: Option<String>,

    /// Exported types from this interface.
    ///
    /// Export names are listed within the types themselves. Note that the
    /// export name here matches the name listed in the `TypeDef`.
    #[serde(serialize_with = "serialize_id_map")]
    pub types: IndexMap<String, TypeId>,

    /// Exported functions from this interface.
    pub functions: IndexMap<String, Function>,

    /// Documentation associated with this interface.
    #[serde(skip_serializing_if = "Docs::is_empty")]
    pub docs: Docs,

    /// The package that owns this interface.
    #[serde(serialize_with = "serialize_optional_id")]
    pub package: Option<PackageId>,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct TypeDef {
    pub name: Option<String>,
    pub kind: TypeDefKind,
    pub owner: TypeOwner,
    #[serde(skip_serializing_if = "Docs::is_empty")]
    pub docs: Docs,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
#[serde(rename_all = "lowercase")]
pub enum TypeDefKind {
    Record(Record),
    Resource,
    Handle(Handle),
    Flags(Flags),
    Tuple(Tuple),
    Variant(Variant),
    Enum(Enum),
    Option(Type),
    Result(Result_),
    List(Type),
    Future(Option<Type>),
    Stream(Stream),
    Type(Type),

    /// This represents a type of unknown structure imported from a foreign
    /// interface.
    ///
    /// This variant is only used during the creation of `UnresolvedPackage` but
    /// by the time a `Resolve` is created then this will not exist.
    Unknown,
}

impl TypeDefKind {
    pub fn as_str(&self) -> &'static str {
        match self {
            TypeDefKind::Record(_) => "record",
            TypeDefKind::Resource => "resource",
            TypeDefKind::Handle(handle) => match handle {
                Handle::Own(_) => "own",
                Handle::Borrow(_) => "borrow",
            },
            TypeDefKind::Flags(_) => "flags",
            TypeDefKind::Tuple(_) => "tuple",
            TypeDefKind::Variant(_) => "variant",
            TypeDefKind::Enum(_) => "enum",
            TypeDefKind::Option(_) => "option",
            TypeDefKind::Result(_) => "result",
            TypeDefKind::List(_) => "list",
            TypeDefKind::Future(_) => "future",
            TypeDefKind::Stream(_) => "stream",
            TypeDefKind::Type(_) => "type",
            TypeDefKind::Unknown => "unknown",
        }
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize)]
#[serde(rename_all = "lowercase")]
pub enum TypeOwner {
    /// This type was defined within a `world` block.
    #[serde(serialize_with = "serialize_id")]
    World(WorldId),
    /// This type was defined within an `interface` block.
    #[serde(serialize_with = "serialize_id")]
    Interface(InterfaceId),
    /// This type wasn't inherently defined anywhere, such as a `list<T>`, which
    /// doesn't need an owner.
    #[serde(untagged, serialize_with = "serialize_none")]
    None,
}

#[derive(Debug, PartialEq, Eq, Hash, Copy, Clone, Serialize)]
#[serde(rename_all = "lowercase")]
pub enum Handle {
    #[serde(serialize_with = "serialize_id")]
    Own(TypeId),
    #[serde(serialize_with = "serialize_id")]
    Borrow(TypeId),
}

#[derive(Debug, PartialEq, Eq, Hash, Copy, Clone)]
pub enum Type {
    Bool,
    U8,
    U16,
    U32,
    U64,
    S8,
    S16,
    S32,
    S64,
    Float32,
    Float64,
    Char,
    String,
    Id(TypeId),
}

#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum Int {
    U8,
    U16,
    U32,
    U64,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Record {
    pub fields: Vec<Field>,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Field {
    pub name: String,
    #[serde(rename = "type")]
    pub ty: Type,
    #[serde(skip_serializing_if = "Docs::is_empty")]
    pub docs: Docs,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Flags {
    pub flags: Vec<Flag>,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Flag {
    pub name: String,
    #[serde(skip_serializing_if = "Docs::is_empty")]
    pub docs: Docs,
}

#[derive(Debug, Clone, PartialEq)]
pub enum FlagsRepr {
    U8,
    U16,
    U32(usize),
}

impl Flags {
    pub fn repr(&self) -> FlagsRepr {
        match self.flags.len() {
            0 => FlagsRepr::U32(0),
            n if n <= 8 => FlagsRepr::U8,
            n if n <= 16 => FlagsRepr::U16,
            n => FlagsRepr::U32(sizealign::align_to(n, 32) / 32),
        }
    }
}

impl FlagsRepr {
    pub fn count(&self) -> usize {
        match self {
            FlagsRepr::U8 => 1,
            FlagsRepr::U16 => 1,
            FlagsRepr::U32(n) => *n,
        }
    }
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Tuple {
    pub types: Vec<Type>,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Variant {
    pub cases: Vec<Case>,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Case {
    pub name: String,
    #[serde(rename = "type")]
    pub ty: Option<Type>,
    #[serde(skip_serializing_if = "Docs::is_empty")]
    pub docs: Docs,
}

impl Variant {
    pub fn tag(&self) -> Int {
        match self.cases.len() {
            n if n <= u8::max_value() as usize => Int::U8,
            n if n <= u16::max_value() as usize => Int::U16,
            n if n <= u32::max_value() as usize => Int::U32,
            _ => panic!("too many cases to fit in a repr"),
        }
    }
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Enum {
    pub cases: Vec<EnumCase>,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct EnumCase {
    pub name: String,
    #[serde(skip_serializing_if = "Docs::is_empty")]
    pub docs: Docs,
}

impl Enum {
    pub fn tag(&self) -> Int {
        match self.cases.len() {
            n if n <= u8::max_value() as usize => Int::U8,
            n if n <= u16::max_value() as usize => Int::U16,
            n if n <= u32::max_value() as usize => Int::U32,
            _ => panic!("too many cases to fit in a repr"),
        }
    }
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Result_ {
    pub ok: Option<Type>,
    pub err: Option<Type>,
}

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Stream {
    pub element: Option<Type>,
    pub end: Option<Type>,
}

#[derive(Clone, Default, Debug, PartialEq, Eq, Serialize)]
pub struct Docs {
    pub contents: Option<String>,
}

impl Docs {
    pub fn is_empty(&self) -> bool {
        self.contents.is_none()
    }
}

pub type Params = Vec<(String, Type)>;

#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
#[serde(untagged)]
pub enum Results {
    #[serde(serialize_with = "serialize_params")]
    Named(Params),
    #[serde(serialize_with = "serialize_anon_result")]
    Anon(Type),
}

pub enum ResultsTypeIter<'a> {
    Named(std::slice::Iter<'a, (String, Type)>),
    Anon(std::iter::Once<&'a Type>),
}

impl<'a> Iterator for ResultsTypeIter<'a> {
    type Item = &'a Type;

    fn next(&mut self) -> Option<&'a Type> {
        match self {
            ResultsTypeIter::Named(ps) => ps.next().map(|p| &p.1),
            ResultsTypeIter::Anon(ty) => ty.next(),
        }
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        match self {
            ResultsTypeIter::Named(ps) => ps.size_hint(),
            ResultsTypeIter::Anon(ty) => ty.size_hint(),
        }
    }
}

impl<'a> ExactSizeIterator for ResultsTypeIter<'a> {}

impl Results {
    // For the common case of an empty results list.
    pub fn empty() -> Results {
        Results::Named(Vec::new())
    }

    pub fn len(&self) -> usize {
        match self {
            Results::Named(params) => params.len(),
            Results::Anon(_) => 1,
        }
    }

    pub fn throws<'a>(&self, resolve: &'a Resolve) -> Option<(Option<&'a Type>, Option<&'a Type>)> {
        if self.len() != 1 {
            return None;
        }
        match self.iter_types().next().unwrap() {
            Type::Id(id) => match &resolve.types[*id].kind {
                TypeDefKind::Result(r) => Some((r.ok.as_ref(), r.err.as_ref())),
                _ => None,
            },
            _ => None,
        }
    }

    pub fn iter_types(&self) -> ResultsTypeIter {
        match self {
            Results::Named(ps) => ResultsTypeIter::Named(ps.iter()),
            Results::Anon(ty) => ResultsTypeIter::Anon(std::iter::once(ty)),
        }
    }
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
pub struct Function {
    pub name: String,
    pub kind: FunctionKind,
    #[serde(serialize_with = "serialize_params")]
    pub params: Params,
    pub results: Results,
    #[serde(skip_serializing_if = "Docs::is_empty")]
    pub docs: Docs,
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
#[serde(rename_all = "lowercase")]
pub enum FunctionKind {
    Freestanding,
    #[serde(serialize_with = "serialize_id")]
    Method(TypeId),
    #[serde(serialize_with = "serialize_id")]
    Static(TypeId),
    #[serde(serialize_with = "serialize_id")]
    Constructor(TypeId),
}

impl Function {
    pub fn item_name(&self) -> &str {
        match &self.kind {
            FunctionKind::Freestanding => &self.name,
            FunctionKind::Method(_) | FunctionKind::Static(_) => {
                &self.name[self.name.find('.').unwrap() + 1..]
            }
            FunctionKind::Constructor(_) => "constructor",
        }
    }

    /// Gets the core export name for this function.
    pub fn core_export_name<'a>(&'a self, interface: Option<&str>) -> Cow<'a, str> {
        match interface {
            Some(interface) => Cow::Owned(format!("{interface}#{}", self.name)),
            None => Cow::Borrowed(&self.name),
        }
    }
}