src/librustdoc/json/mod.rs

   1 //! Rustdoc's JSON backend
   2 //!
   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.
   6
   7 mod conversions;
   8 mod import_finder;
   9
  10 use std::cell::RefCell;
  11 use std::fs::{create_dir_all, File};
  12 use std::io::{BufWriter, Write};
  13 use std::path::PathBuf;
  14 use std::rc::Rc;
  15
  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;
  21
  22 use rustdoc_json_types as types;
  23
  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};
  33
  34 #[derive(Clone)]
  35 pub(crate) struct JsonRenderer<'tcx> {
  36     tcx: TyCtxt<'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.
  41     out_path: PathBuf,
  42     cache: Rc<Cache>,
  43     imported_items: FxHashSet<DefId>,
  44 }
  45
  46 impl<'tcx> JsonRenderer<'tcx> {
  47     fn sess(&self) -> &'tcx Session {
  48         self.tcx.sess
  49     }
  50
  51     fn get_trait_implementors(&mut self, id: DefId) -> Vec<types::Id> {
  52         Rc::clone(&self.cache)
  53             .implementors
  54             .get(&id)
  55             .map(|implementors| {
  56                 implementors
  57                     .iter()
  58                     .map(|i| {
  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)
  62                     })
  63                     .collect()
  64             })
  65             .unwrap_or_default()
  66     }
  67
  68     fn get_impls(&mut self, id: DefId) -> Vec<types::Id> {
  69         Rc::clone(&self.cache)
  70             .impls
  71             .get(&id)
  72             .map(|impls| {
  73                 impls
  74                     .iter()
  75                     .filter_map(|i| {
  76                         let item = &i.impl_item;
  77
  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
  81                         // `doc(primitive)`.
  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;
  87                                 }
  88                             }
  89                         }
  90
  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))
  94                         } else {
  95                             None
  96                         }
  97                     })
  98                     .collect()
  99             })
 100             .unwrap_or_default()
 101     }
 102
 103     fn get_trait_items(&mut self) -> Vec<(types::Id, types::Item)> {
 104         debug!("Adding foreign trait items");
 105         Rc::clone(&self.cache)
 106             .traits
 107             .iter()
 108             .filter_map(|(&id, trait_item)| {
 109                 // only need to synthesize items for external traits
 110                 if !id.is_local() {
 111                     let trait_item = &trait_item.trait_;
 112                     for item in &trait_item.items {
 113                         trace!("Adding subitem to {id:?}: {:?}", item.item_id);
 114                         self.item(item.clone()).unwrap();
 115                     }
 116                     let item_id = from_item_id(id.into(), self.tcx);
 117                     Some((
 118                         item_id.clone(),
 119                         types::Item {
 120                             id: item_id,
 121                             crate_id: id.krate.as_u32(),
 122                             name: self
 123                                 .cache
 124                                 .paths
 125                                 .get(&id)
 126                                 .unwrap_or_else(|| {
 127                                     self.cache
 128                                         .external_paths
 129                                         .get(&id)
 130                                         .expect("Trait should either be in local or external paths")
 131                                 })
 132                                 .0
 133                                 .last()
 134                                 .map(|s| s.to_string()),
 135                             visibility: types::Visibility::Public,
 136                             inner: types::ItemEnum::Trait(trait_item.clone().into_tcx(self.tcx)),
 137                             span: None,
 138                             docs: Default::default(),
 139                             links: Default::default(),
 140                             attrs: Default::default(),
 141                             deprecation: Default::default(),
 142                         },
 143                     ))
 144                 } else {
 145                     None
 146                 }
 147             })
 148             .collect()
 149     }
 150 }
 151
 152 impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
 153     fn descr() -> &'static str {
 154         "json"
 155     }
 156
 157     const RUN_ON_MODULE: bool = false;
 158
 159     fn init(
 160         krate: clean::Crate,
 161         options: RenderOptions,
 162         cache: Cache,
 163         tcx: TyCtxt<'tcx>,
 164     ) -> Result<(Self, clean::Crate), Error> {
 165         debug!("Initializing json renderer");
 166
 167         let (krate, imported_items) = import_finder::get_imports(krate);
 168
 169         Ok((
 170             JsonRenderer {
 171                 tcx,
 172                 index: Rc::new(RefCell::new(FxHashMap::default())),
 173                 out_path: options.output,
 174                 cache: Rc::new(cache),
 175                 imported_items,
 176             },
 177             krate,
 178         ))
 179     }
 180
 181     fn make_child_renderer(&self) -> Self {
 182         self.clone()
 183     }
 184
 185     /// Inserts an item into the index. This should be used rather than directly calling insert on
 186     /// the hashmap because certain items (traits and types) need to have their mappings for trait
 187     /// implementations filled out before they're inserted.
 188     fn item(&mut self, item: clean::Item) -> Result<(), Error> {
 189         let item_type = item.type_();
 190         let item_name = item.name;
 191         trace!("rendering {} {:?}", item_type, item_name);
 192
 193         // Flatten items that recursively store other items. We include orphaned items from
 194         // stripped modules and etc that are otherwise reachable.
 195         if let ItemKind::StrippedItem(inner) = &*item.kind {
 196             inner.inner_items().for_each(|i| self.item(i.clone()).unwrap());
 197         }
 198
 199         // Flatten items that recursively store other items
 200         item.kind.inner_items().for_each(|i| self.item(i.clone()).unwrap());
 201
 202         let name = item.name;
 203         let item_id = item.item_id;
 204         if let Some(mut new_item) = self.convert_item(item) {
 205             let can_be_ignored = match new_item.inner {
 206                 types::ItemEnum::Trait(ref mut t) => {
 207                     t.implementations = self.get_trait_implementors(item_id.expect_def_id());
 208                     false
 209                 }
 210                 types::ItemEnum::Struct(ref mut s) => {
 211                     s.impls = self.get_impls(item_id.expect_def_id());
 212                     false
 213                 }
 214                 types::ItemEnum::Enum(ref mut e) => {
 215                     e.impls = self.get_impls(item_id.expect_def_id());
 216                     false
 217                 }
 218                 types::ItemEnum::Union(ref mut u) => {
 219                     u.impls = self.get_impls(item_id.expect_def_id());
 220                     false
 221                 }
 222
 223                 types::ItemEnum::Method(_)
 224                 | types::ItemEnum::Module(_)
 225                 | types::ItemEnum::AssocConst { .. }
 226                 | types::ItemEnum::AssocType { .. }
 227                 | types::ItemEnum::PrimitiveType(_) => true,
 228                 types::ItemEnum::ExternCrate { .. }
 229                 | types::ItemEnum::Import(_)
 230                 | types::ItemEnum::StructField(_)
 231                 | types::ItemEnum::Variant(_)
 232                 | types::ItemEnum::Function(_)
 233                 | types::ItemEnum::TraitAlias(_)
 234                 | types::ItemEnum::Impl(_)
 235                 | types::ItemEnum::Typedef(_)
 236                 | types::ItemEnum::OpaqueTy(_)
 237                 | types::ItemEnum::Constant(_)
 238                 | types::ItemEnum::Static(_)
 239                 | types::ItemEnum::ForeignType
 240                 | types::ItemEnum::Macro(_)
 241                 | types::ItemEnum::ProcMacro(_) => false,
 242             };
 243             let removed = self
 244                 .index
 245                 .borrow_mut()
 246                 .insert(from_item_id_with_name(item_id, self.tcx, name), new_item.clone());
 247
 248             // FIXME(adotinthevoid): Currently, the index is duplicated. This is a sanity check
 249             // to make sure the items are unique. The main place this happens is when an item, is
 250             // reexported in more than one place. See `rustdoc-json/reexport/in_root_and_mod`
 251             if let Some(old_item) = removed {
 252                 // In case of generic implementations (like `impl<T> Trait for T {}`), all the
 253                 // inner items will be duplicated so we can ignore if they are slightly different.
 254                 if !can_be_ignored {
 255                     assert_eq!(old_item, new_item);
 256                 }
 257             }
 258         }
 259
 260         trace!("done rendering {} {:?}", item_type, item_name);
 261         Ok(())
 262     }
 263
 264     fn mod_item_in(&mut self, _item: &clean::Item) -> Result<(), Error> {
 265         unreachable!("RUN_ON_MODULE = false should never call mod_item_in")
 266     }
 267
 268     fn after_krate(&mut self) -> Result<(), Error> {
 269         debug!("Done with crate");
 270
 271         debug!("Adding Primitve impls");
 272         for primitive in Rc::clone(&self.cache).primitive_locations.values() {
 273             self.get_impls(*primitive);
 274         }
 275
 276         let e = ExternalCrate { crate_num: LOCAL_CRATE };
 277
 278         // FIXME(adotinthevoid): Remove this, as it's not consistant with not
 279         // inlining foreign items.
 280         let foreign_trait_items = self.get_trait_items();
 281         let mut index = (*self.index).clone().into_inner();
 282         index.extend(foreign_trait_items);
 283
 284         debug!("Constructing Output");
 285         // This needs to be the default HashMap for compatibility with the public interface for
 286         // rustdoc-json-types
 287         #[allow(rustc::default_hash_types)]
 288         let output = types::Crate {
 289             root: types::Id(format!("0:0:{}", e.name(self.tcx).as_u32())),
 290             crate_version: self.cache.crate_version.clone(),
 291             includes_private: self.cache.document_private,
 292             index: index.into_iter().collect(),
 293             paths: self
 294                 .cache
 295                 .paths
 296                 .iter()
 297                 .chain(&self.cache.external_paths)
 298                 .map(|(&k, &(ref path, kind))| {
 299                     (
 300                         from_item_id(k.into(), self.tcx),
 301                         types::ItemSummary {
 302                             crate_id: k.krate.as_u32(),
 303                             path: path.iter().map(|s| s.to_string()).collect(),
 304                             kind: kind.into_tcx(self.tcx),
 305                         },
 306                     )
 307                 })
 308                 .collect(),
 309             external_crates: self
 310                 .cache
 311                 .extern_locations
 312                 .iter()
 313                 .map(|(crate_num, external_location)| {
 314                     let e = ExternalCrate { crate_num: *crate_num };
 315                     (
 316                         crate_num.as_u32(),
 317                         types::ExternalCrate {
 318                             name: e.name(self.tcx).to_string(),
 319                             html_root_url: match external_location {
 320                                 ExternalLocation::Remote(s) => Some(s.clone()),
 321                                 _ => None,
 322                             },
 323                         },
 324                     )
 325                 })
 326                 .collect(),
 327             format_version: types::FORMAT_VERSION,
 328         };
 329         let out_dir = self.out_path.clone();
 330         try_err!(create_dir_all(&out_dir), out_dir);
 331
 332         let mut p = out_dir;
 333         p.push(output.index.get(&output.root).unwrap().name.clone().unwrap());
 334         p.set_extension("json");
 335         let mut file = BufWriter::new(try_err!(File::create(&p), p));
 336         serde_json::ser::to_writer(&mut file, &output).unwrap();
 337         try_err!(file.flush(), p);
 338
 339         Ok(())
 340     }
 341
 342     fn cache(&self) -> &Cache {
 343         &self.cache
 344     }
 345 }