summaryrefslogtreecommitdiffstats
path: root/src/librustdoc/html/render/search_index.rs
blob: 8eb9c07f8a7964d9440383c8519052fa6372c20a (plain)
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
use std::collections::hash_map::Entry;
use std::collections::BTreeMap;

use rustc_data_structures::fx::FxHashMap;
use rustc_middle::ty::TyCtxt;
use rustc_span::def_id::LOCAL_CRATE;
use rustc_span::symbol::Symbol;
use serde::ser::{Serialize, SerializeStruct, Serializer};

use crate::clean;
use crate::clean::types::{
    FnRetTy, Function, GenericBound, Generics, ItemId, Type, WherePredicate,
};
use crate::formats::cache::{Cache, OrphanImplItem};
use crate::formats::item_type::ItemType;
use crate::html::format::join_with_double_colon;
use crate::html::markdown::short_markdown_summary;
use crate::html::render::{IndexItem, IndexItemFunctionType, RenderType, RenderTypeId};

/// Builds the search index from the collected metadata
pub(crate) fn build_index<'tcx>(
    krate: &clean::Crate,
    cache: &mut Cache,
    tcx: TyCtxt<'tcx>,
) -> String {
    let mut itemid_to_pathid = FxHashMap::default();
    let mut crate_paths = vec![];

    // Attach all orphan items to the type's definition if the type
    // has since been learned.
    for &OrphanImplItem { parent, ref item, ref impl_generics } in &cache.orphan_impl_items {
        if let Some(&(ref fqp, _)) = cache.paths.get(&parent) {
            let desc = item
                .doc_value()
                .map_or_else(String::new, |s| short_markdown_summary(&s, &item.link_names(cache)));
            cache.search_index.push(IndexItem {
                ty: item.type_(),
                name: item.name.unwrap().to_string(),
                path: join_with_double_colon(&fqp[..fqp.len() - 1]),
                desc,
                parent: Some(parent),
                parent_idx: None,
                search_type: get_function_type_for_search(item, tcx, impl_generics.as_ref(), cache),
                aliases: item.attrs.get_doc_aliases(),
            });
        }
    }

    let crate_doc = krate
        .module
        .doc_value()
        .map_or_else(String::new, |s| short_markdown_summary(&s, &krate.module.link_names(cache)));

    // Aliases added through `#[doc(alias = "...")]`. Since a few items can have the same alias,
    // we need the alias element to have an array of items.
    let mut aliases: BTreeMap<String, Vec<usize>> = BTreeMap::new();

    // Sort search index items. This improves the compressibility of the search index.
    cache.search_index.sort_unstable_by(|k1, k2| {
        // `sort_unstable_by_key` produces lifetime errors
        let k1 = (&k1.path, &k1.name, &k1.ty, &k1.parent);
        let k2 = (&k2.path, &k2.name, &k2.ty, &k2.parent);
        std::cmp::Ord::cmp(&k1, &k2)
    });

    // Set up alias indexes.
    for (i, item) in cache.search_index.iter().enumerate() {
        for alias in &item.aliases[..] {
            aliases.entry(alias.as_str().to_lowercase()).or_default().push(i);
        }
    }

    // Reduce `DefId` in paths into smaller sequential numbers,
    // and prune the paths that do not appear in the index.
    let mut lastpath = "";
    let mut lastpathid = 0usize;

    // First, on function signatures
    let mut search_index = std::mem::replace(&mut cache.search_index, Vec::new());
    for item in search_index.iter_mut() {
        fn convert_render_type(
            ty: &mut RenderType,
            cache: &mut Cache,
            itemid_to_pathid: &mut FxHashMap<ItemId, usize>,
            lastpathid: &mut usize,
            crate_paths: &mut Vec<(ItemType, Symbol)>,
        ) {
            if let Some(generics) = &mut ty.generics {
                for item in generics {
                    convert_render_type(item, cache, itemid_to_pathid, lastpathid, crate_paths);
                }
            }
            let Cache { ref paths, ref external_paths, .. } = *cache;
            let Some(id) = ty.id.clone() else {
                assert!(ty.generics.is_some());
                return;
            };
            let (itemid, path, item_type) = match id {
                RenderTypeId::DefId(defid) => {
                    if let Some(&(ref fqp, item_type)) =
                        paths.get(&defid).or_else(|| external_paths.get(&defid))
                    {
                        (ItemId::DefId(defid), *fqp.last().unwrap(), item_type)
                    } else {
                        ty.id = None;
                        return;
                    }
                }
                RenderTypeId::Primitive(primitive) => (
                    ItemId::Primitive(primitive, LOCAL_CRATE),
                    primitive.as_sym(),
                    ItemType::Primitive,
                ),
                RenderTypeId::Index(_) => return,
            };
            match itemid_to_pathid.entry(itemid) {
                Entry::Occupied(entry) => ty.id = Some(RenderTypeId::Index(*entry.get())),
                Entry::Vacant(entry) => {
                    let pathid = *lastpathid;
                    entry.insert(pathid);
                    *lastpathid += 1;
                    crate_paths.push((item_type, path));
                    ty.id = Some(RenderTypeId::Index(pathid));
                }
            }
        }
        if let Some(search_type) = &mut item.search_type {
            for item in &mut search_type.inputs {
                convert_render_type(
                    item,
                    cache,
                    &mut itemid_to_pathid,
                    &mut lastpathid,
                    &mut crate_paths,
                );
            }
            for item in &mut search_type.output {
                convert_render_type(
                    item,
                    cache,
                    &mut itemid_to_pathid,
                    &mut lastpathid,
                    &mut crate_paths,
                );
            }
        }
    }

    let Cache { ref paths, .. } = *cache;

    // Then, on parent modules
    let crate_items: Vec<&IndexItem> = search_index
        .iter_mut()
        .map(|item| {
            item.parent_idx =
                item.parent.and_then(|defid| match itemid_to_pathid.entry(ItemId::DefId(defid)) {
                    Entry::Occupied(entry) => Some(*entry.get()),
                    Entry::Vacant(entry) => {
                        let pathid = lastpathid;
                        entry.insert(pathid);
                        lastpathid += 1;

                        if let Some(&(ref fqp, short)) = paths.get(&defid) {
                            crate_paths.push((short, *fqp.last().unwrap()));
                            Some(pathid)
                        } else {
                            None
                        }
                    }
                });

            // Omit the parent path if it is same to that of the prior item.
            if lastpath == &item.path {
                item.path.clear();
            } else {
                lastpath = &item.path;
            }

            &*item
        })
        .collect();

    struct CrateData<'a> {
        doc: String,
        items: Vec<&'a IndexItem>,
        paths: Vec<(ItemType, Symbol)>,
        // The String is alias name and the vec is the list of the elements with this alias.
        //
        // To be noted: the `usize` elements are indexes to `items`.
        aliases: &'a BTreeMap<String, Vec<usize>>,
    }

    impl<'a> Serialize for CrateData<'a> {
        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
        where
            S: Serializer,
        {
            let has_aliases = !self.aliases.is_empty();
            let mut crate_data =
                serializer.serialize_struct("CrateData", if has_aliases { 9 } else { 8 })?;
            crate_data.serialize_field("doc", &self.doc)?;
            crate_data.serialize_field(
                "t",
                &self.items.iter().map(|item| &item.ty).collect::<Vec<_>>(),
            )?;
            crate_data.serialize_field(
                "n",
                &self.items.iter().map(|item| &item.name).collect::<Vec<_>>(),
            )?;
            crate_data.serialize_field(
                "q",
                &self.items.iter().map(|item| &item.path).collect::<Vec<_>>(),
            )?;
            crate_data.serialize_field(
                "d",
                &self.items.iter().map(|item| &item.desc).collect::<Vec<_>>(),
            )?;
            crate_data.serialize_field(
                "i",
                &self
                    .items
                    .iter()
                    .map(|item| {
                        assert_eq!(
                            item.parent.is_some(),
                            item.parent_idx.is_some(),
                            "`{}` is missing idx",
                            item.name
                        );
                        // 0 is a sentinel, everything else is one-indexed
                        item.parent_idx.map(|x| x + 1).unwrap_or(0)
                    })
                    .collect::<Vec<_>>(),
            )?;
            crate_data.serialize_field(
                "f",
                &self
                    .items
                    .iter()
                    .map(|item| {
                        // Fake option to get `0` out as a sentinel instead of `null`.
                        // We want to use `0` because it's three less bytes.
                        enum FunctionOption<'a> {
                            Function(&'a IndexItemFunctionType),
                            None,
                        }
                        impl<'a> Serialize for FunctionOption<'a> {
                            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                            where
                                S: Serializer,
                            {
                                match self {
                                    FunctionOption::None => 0.serialize(serializer),
                                    FunctionOption::Function(ty) => ty.serialize(serializer),
                                }
                            }
                        }
                        match &item.search_type {
                            Some(ty) => FunctionOption::Function(ty),
                            None => FunctionOption::None,
                        }
                    })
                    .collect::<Vec<_>>(),
            )?;
            crate_data.serialize_field(
                "p",
                &self.paths.iter().map(|(it, s)| (it, s.to_string())).collect::<Vec<_>>(),
            )?;
            if has_aliases {
                crate_data.serialize_field("a", &self.aliases)?;
            }
            crate_data.end()
        }
    }

    // Collect the index into a string
    format!(
        r#""{}":{}"#,
        krate.name(tcx),
        serde_json::to_string(&CrateData {
            doc: crate_doc,
            items: crate_items,
            paths: crate_paths,
            aliases: &aliases,
        })
        .expect("failed serde conversion")
        // All these `replace` calls are because we have to go through JS string for JSON content.
        .replace('\\', r"\\")
        .replace('\'', r"\'")
        // We need to escape double quotes for the JSON.
        .replace("\\\"", "\\\\\"")
    )
}

pub(crate) fn get_function_type_for_search<'tcx>(
    item: &clean::Item,
    tcx: TyCtxt<'tcx>,
    impl_generics: Option<&(clean::Type, clean::Generics)>,
    cache: &Cache,
) -> Option<IndexItemFunctionType> {
    let (mut inputs, mut output) = match *item.kind {
        clean::FunctionItem(ref f) => get_fn_inputs_and_outputs(f, tcx, impl_generics, cache),
        clean::MethodItem(ref m, _) => get_fn_inputs_and_outputs(m, tcx, impl_generics, cache),
        clean::TyMethodItem(ref m) => get_fn_inputs_and_outputs(m, tcx, impl_generics, cache),
        _ => return None,
    };

    inputs.retain(|a| a.id.is_some() || a.generics.is_some());
    output.retain(|a| a.id.is_some() || a.generics.is_some());

    Some(IndexItemFunctionType { inputs, output })
}

fn get_index_type(clean_type: &clean::Type, generics: Vec<RenderType>) -> RenderType {
    RenderType {
        id: get_index_type_id(clean_type),
        generics: if generics.is_empty() { None } else { Some(generics) },
    }
}

fn get_index_type_id(clean_type: &clean::Type) -> Option<RenderTypeId> {
    match *clean_type {
        clean::Type::Path { ref path, .. } => Some(RenderTypeId::DefId(path.def_id())),
        clean::DynTrait(ref bounds, _) => {
            let path = &bounds[0].trait_;
            Some(RenderTypeId::DefId(path.def_id()))
        }
        clean::Primitive(p) => Some(RenderTypeId::Primitive(p)),
        clean::BorrowedRef { ref type_, .. } | clean::RawPointer(_, ref type_) => {
            get_index_type_id(type_)
        }
        clean::BareFunction(_)
        | clean::Generic(_)
        | clean::ImplTrait(_)
        | clean::Tuple(_)
        | clean::Slice(_)
        | clean::Array(_, _)
        | clean::QPath { .. }
        | clean::Infer => None,
    }
}

/// The point of this function is to replace bounds with types.
///
/// i.e. `[T, U]` when you have the following bounds: `T: Display, U: Option<T>` will return
/// `[Display, Option]`. If a type parameter has no trait bound, it is discarded.
///
/// Important note: It goes through generics recursively. So if you have
/// `T: Option<Result<(), ()>>`, it'll go into `Option` and then into `Result`.
#[instrument(level = "trace", skip(tcx, res, cache))]
fn add_generics_and_bounds_as_types<'tcx, 'a>(
    self_: Option<&'a Type>,
    generics: &Generics,
    arg: &'a Type,
    tcx: TyCtxt<'tcx>,
    recurse: usize,
    res: &mut Vec<RenderType>,
    cache: &Cache,
) {
    fn insert_ty(res: &mut Vec<RenderType>, ty: Type, mut generics: Vec<RenderType>) {
        // generics and impl trait are both identified by their generics,
        // rather than a type name itself
        let anonymous = ty.is_full_generic() || ty.is_impl_trait();
        let generics_empty = generics.is_empty();

        if anonymous {
            if generics_empty {
                // This is a type parameter with no trait bounds (for example: `T` in
                // `fn f<T>(p: T)`, so not useful for the rustdoc search because we would end up
                // with an empty type with an empty name. Let's just discard it.
                return;
            } else if generics.len() == 1 {
                // In this case, no need to go through an intermediate state if the type parameter
                // contains only one trait bound.
                //
                // For example:
                //
                // `fn foo<T: Display>(r: Option<T>) {}`
                //
                // In this case, it would contain:
                //
                // ```
                // [{
                //     name: "option",
                //     generics: [{
                //         name: "",
                //         generics: [
                //             name: "Display",
                //             generics: []
                //         }]
                //     }]
                // }]
                // ```
                //
                // After removing the intermediate (unnecessary) type parameter, it'll become:
                //
                // ```
                // [{
                //     name: "option",
                //     generics: [{
                //         name: "Display",
                //         generics: []
                //     }]
                // }]
                // ```
                //
                // To be noted that it can work if there is ONLY ONE trait bound, otherwise we still
                // need to keep it as is!
                res.push(generics.pop().unwrap());
                return;
            }
        }
        let index_ty = get_index_type(&ty, generics);
        if index_ty.id.is_none() && generics_empty {
            return;
        }
        res.push(index_ty);
    }

    if recurse >= 10 {
        // FIXME: remove this whole recurse thing when the recursion bug is fixed
        // See #59502 for the original issue.
        return;
    }

    // First, check if it's "Self".
    let arg = if let Some(self_) = self_ {
        match &*arg {
            Type::BorrowedRef { type_, .. } if type_.is_self_type() => self_,
            type_ if type_.is_self_type() => self_,
            arg => arg,
        }
    } else {
        arg
    };

    // If this argument is a type parameter and not a trait bound or a type, we need to look
    // for its bounds.
    if let Type::Generic(arg_s) = *arg {
        // First we check if the bounds are in a `where` predicate...
        if let Some(where_pred) = generics.where_predicates.iter().find(|g| match g {
            WherePredicate::BoundPredicate { ty, .. } => ty.def_id(cache) == arg.def_id(cache),
            _ => false,
        }) {
            let mut ty_generics = Vec::new();
            let bounds = where_pred.get_bounds().unwrap_or_else(|| &[]);
            for bound in bounds.iter() {
                if let GenericBound::TraitBound(poly_trait, _) = bound {
                    for param_def in poly_trait.generic_params.iter() {
                        match &param_def.kind {
                            clean::GenericParamDefKind::Type { default: Some(ty), .. } => {
                                add_generics_and_bounds_as_types(
                                    self_,
                                    generics,
                                    ty,
                                    tcx,
                                    recurse + 1,
                                    &mut ty_generics,
                                    cache,
                                )
                            }
                            _ => {}
                        }
                    }
                }
            }
            insert_ty(res, arg.clone(), ty_generics);
        }
        // Otherwise we check if the trait bounds are "inlined" like `T: Option<u32>`...
        if let Some(bound) = generics.params.iter().find(|g| g.is_type() && g.name == arg_s) {
            let mut ty_generics = Vec::new();
            for bound in bound.get_bounds().unwrap_or(&[]) {
                if let Some(path) = bound.get_trait_path() {
                    let ty = Type::Path { path };
                    add_generics_and_bounds_as_types(
                        self_,
                        generics,
                        &ty,
                        tcx,
                        recurse + 1,
                        &mut ty_generics,
                        cache,
                    );
                }
            }
            insert_ty(res, arg.clone(), ty_generics);
        }
    } else if let Type::ImplTrait(ref bounds) = *arg {
        let mut ty_generics = Vec::new();
        for bound in bounds {
            if let Some(path) = bound.get_trait_path() {
                let ty = Type::Path { path };
                add_generics_and_bounds_as_types(
                    self_,
                    generics,
                    &ty,
                    tcx,
                    recurse + 1,
                    &mut ty_generics,
                    cache,
                );
            }
        }
        insert_ty(res, arg.clone(), ty_generics);
    } else {
        // This is not a type parameter. So for example if we have `T, U: Option<T>`, and we're
        // looking at `Option`, we enter this "else" condition, otherwise if it's `T`, we don't.
        //
        // So in here, we can add it directly and look for its own type parameters (so for `Option`,
        // we will look for them but not for `T`).
        let mut ty_generics = Vec::new();
        if let Some(arg_generics) = arg.generics() {
            for gen in arg_generics.iter() {
                add_generics_and_bounds_as_types(
                    self_,
                    generics,
                    gen,
                    tcx,
                    recurse + 1,
                    &mut ty_generics,
                    cache,
                );
            }
        }
        insert_ty(res, arg.clone(), ty_generics);
    }
}

/// Return the full list of types when bounds have been resolved.
///
/// i.e. `fn foo<A: Display, B: Option<A>>(x: u32, y: B)` will return
/// `[u32, Display, Option]`.
fn get_fn_inputs_and_outputs<'tcx>(
    func: &Function,
    tcx: TyCtxt<'tcx>,
    impl_generics: Option<&(clean::Type, clean::Generics)>,
    cache: &Cache,
) -> (Vec<RenderType>, Vec<RenderType>) {
    let decl = &func.decl;

    let combined_generics;
    let (self_, generics) = if let Some(&(ref impl_self, ref impl_generics)) = impl_generics {
        match (impl_generics.is_empty(), func.generics.is_empty()) {
            (true, _) => (Some(impl_self), &func.generics),
            (_, true) => (Some(impl_self), impl_generics),
            (false, false) => {
                let params =
                    func.generics.params.iter().chain(&impl_generics.params).cloned().collect();
                let where_predicates = func
                    .generics
                    .where_predicates
                    .iter()
                    .chain(&impl_generics.where_predicates)
                    .cloned()
                    .collect();
                combined_generics = clean::Generics { params, where_predicates };
                (Some(impl_self), &combined_generics)
            }
        }
    } else {
        (None, &func.generics)
    };

    let mut all_types = Vec::new();
    for arg in decl.inputs.values.iter() {
        let mut args = Vec::new();
        add_generics_and_bounds_as_types(self_, generics, &arg.type_, tcx, 0, &mut args, cache);
        if !args.is_empty() {
            all_types.extend(args);
        } else {
            all_types.push(get_index_type(&arg.type_, vec![]));
        }
    }

    let mut ret_types = Vec::new();
    match decl.output {
        FnRetTy::Return(ref return_type) => {
            add_generics_and_bounds_as_types(
                self_,
                generics,
                return_type,
                tcx,
                0,
                &mut ret_types,
                cache,
            );
            if ret_types.is_empty() {
                ret_types.push(get_index_type(return_type, vec![]));
            }
        }
        _ => {}
    };
    (all_types, ret_types)
}