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;
  17 use rustc_hir::def_id::{DefId, DefIdSet};
  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::{id_from_item, id_from_item_default, 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: DefIdSet,
  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                         id_from_item(&item, self.tcx)
  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                         // `rustc_doc_primitive`.
  82                         let mut is_primitive_impl = false;
  83                         if let clean::types::ItemKind::ImplItem(ref impl_) = *item.kind &&
  84                             impl_.trait_.is_none() &&
  85                             let clean::types::Type::Primitive(_) = impl_.for_
  86                         {
  87                             is_primitive_impl = true;
  88                         }
  89
  90                         if item.item_id.is_local() || is_primitive_impl {
  91                             self.item(item.clone()).unwrap();
  92                             Some(id_from_item(&item, self.tcx))
  93                         } else {
  94                             None
  95                         }
  96                     })
  97                     .collect()
  98             })
  99             .unwrap_or_default()
 100     }
 101 }
 102
 103 impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
 104     fn descr() -> &'static str {
 105         "json"
 106     }
 107
 108     const RUN_ON_MODULE: bool = false;
 109
 110     fn init(
 111         krate: clean::Crate,
 112         options: RenderOptions,
 113         cache: Cache,
 114         tcx: TyCtxt<'tcx>,
 115     ) -> Result<(Self, clean::Crate), Error> {
 116         debug!("Initializing json renderer");
 117
 118         let (krate, imported_items) = import_finder::get_imports(krate);
 119
 120         Ok((
 121             JsonRenderer {
 122                 tcx,
 123                 index: Rc::new(RefCell::new(FxHashMap::default())),
 124                 out_path: options.output,
 125                 cache: Rc::new(cache),
 126                 imported_items,
 127             },
 128             krate,
 129         ))
 130     }
 131
 132     fn make_child_renderer(&self) -> Self {
 133         self.clone()
 134     }
 135
 136     /// Inserts an item into the index. This should be used rather than directly calling insert on
 137     /// the hashmap because certain items (traits and types) need to have their mappings for trait
 138     /// implementations filled out before they're inserted.
 139     fn item(&mut self, item: clean::Item) -> Result<(), Error> {
 140         let item_type = item.type_();
 141         let item_name = item.name;
 142         trace!("rendering {item_type} {item_name:?}");
 143
 144         // Flatten items that recursively store other items. We include orphaned items from
 145         // stripped modules and etc that are otherwise reachable.
 146         if let ItemKind::StrippedItem(inner) = &*item.kind {
 147             inner.inner_items().for_each(|i| self.item(i.clone()).unwrap());
 148         }
 149
 150         // Flatten items that recursively store other items
 151         item.kind.inner_items().for_each(|i| self.item(i.clone()).unwrap());
 152
 153         let item_id = item.item_id;
 154         if let Some(mut new_item) = self.convert_item(item) {
 155             let can_be_ignored = match new_item.inner {
 156                 types::ItemEnum::Trait(ref mut t) => {
 157                     t.implementations = self.get_trait_implementors(item_id.expect_def_id());
 158                     false
 159                 }
 160                 types::ItemEnum::Struct(ref mut s) => {
 161                     s.impls = self.get_impls(item_id.expect_def_id());
 162                     false
 163                 }
 164                 types::ItemEnum::Enum(ref mut e) => {
 165                     e.impls = self.get_impls(item_id.expect_def_id());
 166                     false
 167                 }
 168                 types::ItemEnum::Union(ref mut u) => {
 169                     u.impls = self.get_impls(item_id.expect_def_id());
 170                     false
 171                 }
 172                 types::ItemEnum::Primitive(ref mut p) => {
 173                     p.impls = self.get_impls(item_id.expect_def_id());
 174                     false
 175                 }
 176
 177                 types::ItemEnum::Function(_)
 178                 | types::ItemEnum::Module(_)
 179                 | types::ItemEnum::Import(_)
 180                 | types::ItemEnum::AssocConst { .. }
 181                 | types::ItemEnum::AssocType { .. } => true,
 182                 types::ItemEnum::ExternCrate { .. }
 183                 | types::ItemEnum::StructField(_)
 184                 | types::ItemEnum::Variant(_)
 185                 | types::ItemEnum::TraitAlias(_)
 186                 | types::ItemEnum::Impl(_)
 187                 | types::ItemEnum::TypeAlias(_)
 188                 | types::ItemEnum::OpaqueTy(_)
 189                 | types::ItemEnum::Constant(_)
 190                 | types::ItemEnum::Static(_)
 191                 | types::ItemEnum::ForeignType
 192                 | types::ItemEnum::Macro(_)
 193                 | types::ItemEnum::ProcMacro(_) => false,
 194             };
 195             let removed = self.index.borrow_mut().insert(new_item.id.clone(), new_item.clone());
 196
 197             // FIXME(adotinthevoid): Currently, the index is duplicated. This is a sanity check
 198             // to make sure the items are unique. The main place this happens is when an item, is
 199             // reexported in more than one place. See `rustdoc-json/reexport/in_root_and_mod`
 200             if let Some(old_item) = removed {
 201                 // In case of generic implementations (like `impl<T> Trait for T {}`), all the
 202                 // inner items will be duplicated so we can ignore if they are slightly different.
 203                 if !can_be_ignored {
 204                     assert_eq!(old_item, new_item);
 205                 }
 206                 trace!("replaced {old_item:?}\nwith {new_item:?}");
 207             }
 208         }
 209
 210         trace!("done rendering {item_type} {item_name:?}");
 211         Ok(())
 212     }
 213
 214     fn mod_item_in(&mut self, _item: &clean::Item) -> Result<(), Error> {
 215         unreachable!("RUN_ON_MODULE = false should never call mod_item_in")
 216     }
 217
 218     fn after_krate(&mut self) -> Result<(), Error> {
 219         debug!("Done with crate");
 220
 221         debug!("Adding Primitive impls");
 222         for primitive in Rc::clone(&self.cache).primitive_locations.values() {
 223             self.get_impls(*primitive);
 224         }
 225
 226         let e = ExternalCrate { crate_num: LOCAL_CRATE };
 227
 228         let index = (*self.index).clone().into_inner();
 229
 230         debug!("Constructing Output");
 231         // This needs to be the default HashMap for compatibility with the public interface for
 232         // rustdoc-json-types
 233         #[allow(rustc::default_hash_types)]
 234         let output = types::Crate {
 235             root: types::Id(format!("0:0:{}", e.name(self.tcx).as_u32())),
 236             crate_version: self.cache.crate_version.clone(),
 237             includes_private: self.cache.document_private,
 238             index: index.into_iter().collect(),
 239             paths: self
 240                 .cache
 241                 .paths
 242                 .iter()
 243                 .chain(&self.cache.external_paths)
 244                 .map(|(&k, &(ref path, kind))| {
 245                     (
 246                         id_from_item_default(k.into(), self.tcx),
 247                         types::ItemSummary {
 248                             crate_id: k.krate.as_u32(),
 249                             path: path.iter().map(|s| s.to_string()).collect(),
 250                             kind: kind.into_tcx(self.tcx),
 251                         },
 252                     )
 253                 })
 254                 .collect(),
 255             external_crates: self
 256                 .cache
 257                 .extern_locations
 258                 .iter()
 259                 .map(|(crate_num, external_location)| {
 260                     let e = ExternalCrate { crate_num: *crate_num };
 261                     (
 262                         crate_num.as_u32(),
 263                         types::ExternalCrate {
 264                             name: e.name(self.tcx).to_string(),
 265                             html_root_url: match external_location {
 266                                 ExternalLocation::Remote(s) => Some(s.clone()),
 267                                 _ => None,
 268                             },
 269                         },
 270                     )
 271                 })
 272                 .collect(),
 273             format_version: types::FORMAT_VERSION,
 274         };
 275         let out_dir = self.out_path.clone();
 276         try_err!(create_dir_all(&out_dir), out_dir);
 277
 278         let mut p = out_dir;
 279         p.push(output.index.get(&output.root).unwrap().name.clone().unwrap());
 280         p.set_extension("json");
 281         let mut file = BufWriter::new(try_err!(File::create(&p), p));
 282         self.tcx
 283             .sess
 284             .time("rustdoc_json_serialization", || serde_json::ser::to_writer(&mut file, &output))
 285             .unwrap();
 286         try_err!(file.flush(), p);
 287
 288         Ok(())
 289     }
 290
 291     fn cache(&self) -> &Cache {
 292         &self.cache
 293     }
 294 }