1 //! Rustdoc's JSON backend
3 //! This module contains the logic for rendering a crate as JSON rather than the normal static HTML
4 //! output. See [the RFC](https://github.com/rust-lang/rfcs/pull/2963) and the [`types`] module
5 //! docs for usage and details.
10 use std::cell::RefCell;
11 use std::fs::{create_dir_all, File};
12 use std::io::{BufWriter, Write};
13 use std::path::PathBuf;
16 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
17 use rustc_hir::def_id::DefId;
18 use rustc_middle::ty::TyCtxt;
19 use rustc_session::Session;
20 use rustc_span::def_id::LOCAL_CRATE;
22 use rustdoc_json_types as types;
24 use crate::clean::types::{ExternalCrate, ExternalLocation};
25 use crate::clean::ItemKind;
26 use crate::config::RenderOptions;
27 use crate::docfs::PathError;
28 use crate::error::Error;
29 use crate::formats::cache::Cache;
30 use crate::formats::FormatRenderer;
31 use crate::json::conversions::{from_item_id, from_item_id_with_name, IntoWithTcx};
32 use crate::{clean, try_err};
35 pub(crate) struct JsonRenderer<'tcx> {
37 /// A mapping of IDs that contains all local items for this crate which gets output as a top
38 /// level field of the JSON blob.
39 index: Rc<RefCell<FxHashMap<types::Id, types::Item>>>,
40 /// The directory where the blob will be written to.
43 imported_items: FxHashSet<DefId>,
46 impl<'tcx> JsonRenderer<'tcx> {
47 fn sess(&self) -> &'tcx Session {
51 fn get_trait_implementors(&mut self, id: DefId) -> Vec<types::Id> {
52 Rc::clone(&self.cache)
59 let item = &i.impl_item;
60 self.item(item.clone()).unwrap();
61 from_item_id_with_name(item.item_id, self.tcx, item.name)
68 fn get_impls(&mut self, id: DefId) -> Vec<types::Id> {
69 Rc::clone(&self.cache)
76 let item = &i.impl_item;
78 // HACK(hkmatsumoto): For impls of primitive types, we index them
79 // regardless of whether they're local. This is because users can
80 // document primitive items in an arbitrary crate by using
82 let mut is_primitive_impl = false;
83 if let clean::types::ItemKind::ImplItem(ref impl_) = *item.kind {
84 if impl_.trait_.is_none() {
85 if let clean::types::Type::Primitive(_) = impl_.for_ {
86 is_primitive_impl = true;
91 if item.item_id.is_local() || is_primitive_impl {
92 self.item(item.clone()).unwrap();
93 Some(from_item_id_with_name(item.item_id, self.tcx, item.name))
103 fn get_trait_items(&mut self) -> Vec<(types::Id, types::Item)> {
104 debug!("Adding foreign trait items");
105 Rc::clone(&self.cache)
108 .filter_map(|(&id, trait_item)| {
109 // only need to synthesize items for external traits
111 for item in &trait_item.items {
112 trace!("Adding subitem to {id:?}: {:?}", item.item_id);
113 self.item(item.clone()).unwrap();
115 let item_id = from_item_id(id.into(), self.tcx);
120 crate_id: id.krate.as_u32(),
129 .expect("Trait should either be in local or external paths")
133 .map(|s| s.to_string()),
134 visibility: types::Visibility::Public,
135 inner: types::ItemEnum::Trait(trait_item.clone().into_tcx(self.tcx)),
137 docs: Default::default(),
138 links: Default::default(),
139 attrs: Default::default(),
140 deprecation: Default::default(),
151 impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
152 fn descr() -> &'static str {
156 const RUN_ON_MODULE: bool = false;
160 options: RenderOptions,
163 ) -> Result<(Self, clean::Crate), Error> {
164 debug!("Initializing json renderer");
166 let (krate, imported_items) = import_finder::get_imports(krate);
171 index: Rc::new(RefCell::new(FxHashMap::default())),
172 out_path: options.output,
173 cache: Rc::new(cache),
180 fn make_child_renderer(&self) -> Self {
184 /// Inserts an item into the index. This should be used rather than directly calling insert on
185 /// the hashmap because certain items (traits and types) need to have their mappings for trait
186 /// implementations filled out before they're inserted.
187 fn item(&mut self, item: clean::Item) -> Result<(), Error> {
188 let item_type = item.type_();
189 let item_name = item.name;
190 trace!("rendering {} {:?}", item_type, item_name);
192 // Flatten items that recursively store other items. We include orphaned items from
193 // stripped modules and etc that are otherwise reachable.
194 if let ItemKind::StrippedItem(inner) = &*item.kind {
195 inner.inner_items().for_each(|i| self.item(i.clone()).unwrap());
198 // Flatten items that recursively store other items
199 item.kind.inner_items().for_each(|i| self.item(i.clone()).unwrap());
201 let name = item.name;
202 let item_id = item.item_id;
203 if let Some(mut new_item) = self.convert_item(item) {
204 let can_be_ignored = match new_item.inner {
205 types::ItemEnum::Trait(ref mut t) => {
206 t.implementations = self.get_trait_implementors(item_id.expect_def_id());
209 types::ItemEnum::Struct(ref mut s) => {
210 s.impls = self.get_impls(item_id.expect_def_id());
213 types::ItemEnum::Enum(ref mut e) => {
214 e.impls = self.get_impls(item_id.expect_def_id());
217 types::ItemEnum::Union(ref mut u) => {
218 u.impls = self.get_impls(item_id.expect_def_id());
221 types::ItemEnum::Primitive(ref mut p) => {
222 p.impls = self.get_impls(item_id.expect_def_id());
226 types::ItemEnum::Function(_)
227 | types::ItemEnum::Module(_)
228 | types::ItemEnum::AssocConst { .. }
229 | types::ItemEnum::AssocType { .. } => true,
230 types::ItemEnum::ExternCrate { .. }
231 | types::ItemEnum::Import(_)
232 | types::ItemEnum::StructField(_)
233 | types::ItemEnum::Variant(_)
234 | types::ItemEnum::TraitAlias(_)
235 | types::ItemEnum::Impl(_)
236 | types::ItemEnum::Typedef(_)
237 | types::ItemEnum::OpaqueTy(_)
238 | types::ItemEnum::Constant(_)
239 | types::ItemEnum::Static(_)
240 | types::ItemEnum::ForeignType
241 | types::ItemEnum::Macro(_)
242 | types::ItemEnum::ProcMacro(_) => false,
247 .insert(from_item_id_with_name(item_id, self.tcx, name), new_item.clone());
249 // FIXME(adotinthevoid): Currently, the index is duplicated. This is a sanity check
250 // to make sure the items are unique. The main place this happens is when an item, is
251 // reexported in more than one place. See `rustdoc-json/reexport/in_root_and_mod`
252 if let Some(old_item) = removed {
253 // In case of generic implementations (like `impl<T> Trait for T {}`), all the
254 // inner items will be duplicated so we can ignore if they are slightly different.
256 assert_eq!(old_item, new_item);
261 trace!("done rendering {} {:?}", item_type, item_name);
265 fn mod_item_in(&mut self, _item: &clean::Item) -> Result<(), Error> {
266 unreachable!("RUN_ON_MODULE = false should never call mod_item_in")
269 fn after_krate(&mut self) -> Result<(), Error> {
270 debug!("Done with crate");
272 debug!("Adding Primitve impls");
273 for primitive in Rc::clone(&self.cache).primitive_locations.values() {
274 self.get_impls(*primitive);
277 let e = ExternalCrate { crate_num: LOCAL_CRATE };
279 // FIXME(adotinthevoid): Remove this, as it's not consistent with not
280 // inlining foreign items.
281 let foreign_trait_items = self.get_trait_items();
282 let mut index = (*self.index).clone().into_inner();
283 index.extend(foreign_trait_items);
285 debug!("Constructing Output");
286 // This needs to be the default HashMap for compatibility with the public interface for
287 // rustdoc-json-types
288 #[allow(rustc::default_hash_types)]
289 let output = types::Crate {
290 root: types::Id(format!("0:0:{}", e.name(self.tcx).as_u32())),
291 crate_version: self.cache.crate_version.clone(),
292 includes_private: self.cache.document_private,
293 index: index.into_iter().collect(),
298 .chain(&self.cache.external_paths)
299 .map(|(&k, &(ref path, kind))| {
301 from_item_id(k.into(), self.tcx),
303 crate_id: k.krate.as_u32(),
304 path: path.iter().map(|s| s.to_string()).collect(),
305 kind: kind.into_tcx(self.tcx),
310 external_crates: self
314 .map(|(crate_num, external_location)| {
315 let e = ExternalCrate { crate_num: *crate_num };
318 types::ExternalCrate {
319 name: e.name(self.tcx).to_string(),
320 html_root_url: match external_location {
321 ExternalLocation::Remote(s) => Some(s.clone()),
328 format_version: types::FORMAT_VERSION,
330 let out_dir = self.out_path.clone();
331 try_err!(create_dir_all(&out_dir), out_dir);
334 p.push(output.index.get(&output.root).unwrap().name.clone().unwrap());
335 p.set_extension("json");
336 let mut file = BufWriter::new(try_err!(File::create(&p), p));
337 serde_json::ser::to_writer(&mut file, &output).unwrap();
338 try_err!(file.flush(), p);
343 fn cache(&self) -> &Cache {