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