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