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
   9 use std::cell::RefCell;
  10 use std::fs::File;
  11 use std::path::PathBuf;
  12 use std::rc::Rc;
  13
  14 use rustc_data_structures::fx::FxHashMap;
  15 use rustc_middle::ty::TyCtxt;
  16 use rustc_session::Session;
  17 use rustc_span::edition::Edition;
  18
  19 use rustdoc_json_types as types;
  20
  21 use crate::clean;
  22 use crate::config::RenderOptions;
  23 use crate::error::Error;
  24 use crate::formats::cache::Cache;
  25 use crate::formats::FormatRenderer;
  26 use crate::html::render::cache::ExternalLocation;
  27 use crate::json::conversions::from_def_id;
  28
  29 #[derive(Clone)]
  30 crate struct JsonRenderer<'tcx> {
  31     tcx: TyCtxt<'tcx>,
  32     /// A mapping of IDs that contains all local items for this crate which gets output as a top
  33     /// level field of the JSON blob.
  34     index: Rc<RefCell<FxHashMap<types::Id, types::Item>>>,
  35     /// The directory where the blob will be written to.
  36     out_path: PathBuf,
  37     cache: Rc<Cache>,
  38 }
  39
  40 impl JsonRenderer<'tcx> {
  41     fn sess(&self) -> &'tcx Session {
  42         self.tcx.sess
  43     }
  44
  45     fn get_trait_implementors(&mut self, id: rustc_span::def_id::DefId) -> Vec<types::Id> {
  46         Rc::clone(&self.cache)
  47             .implementors
  48             .get(&id)
  49             .map(|implementors| {
  50                 implementors
  51                     .iter()
  52                     .map(|i| {
  53                         let item = &i.impl_item;
  54                         self.item(item.clone()).unwrap();
  55                         from_def_id(item.def_id)
  56                     })
  57                     .collect()
  58             })
  59             .unwrap_or_default()
  60     }
  61
  62     fn get_impls(&mut self, id: rustc_span::def_id::DefId) -> Vec<types::Id> {
  63         Rc::clone(&self.cache)
  64             .impls
  65             .get(&id)
  66             .map(|impls| {
  67                 impls
  68                     .iter()
  69                     .filter_map(|i| {
  70                         let item = &i.impl_item;
  71                         if item.def_id.is_local() {
  72                             self.item(item.clone()).unwrap();
  73                             Some(from_def_id(item.def_id))
  74                         } else {
  75                             None
  76                         }
  77                     })
  78                     .collect()
  79             })
  80             .unwrap_or_default()
  81     }
  82
  83     fn get_trait_items(&mut self) -> Vec<(types::Id, types::Item)> {
  84         Rc::clone(&self.cache)
  85             .traits
  86             .iter()
  87             .filter_map(|(&id, trait_item)| {
  88                 // only need to synthesize items for external traits
  89                 if !id.is_local() {
  90                     let trait_item = &trait_item.trait_;
  91                     trait_item.items.clone().into_iter().for_each(|i| self.item(i).unwrap());
  92                     Some((
  93                         from_def_id(id),
  94                         types::Item {
  95                             id: from_def_id(id),
  96                             crate_id: id.krate.as_u32(),
  97                             name: self
  98                                 .cache
  99                                 .paths
 100                                 .get(&id)
 101                                 .unwrap_or_else(|| {
 102                                     self.cache
 103                                         .external_paths
 104                                         .get(&id)
 105                                         .expect("Trait should either be in local or external paths")
 106                                 })
 107                                 .0
 108                                 .last()
 109                                 .map(Clone::clone),
 110                             visibility: types::Visibility::Public,
 111                             inner: types::ItemEnum::Trait(trait_item.clone().into()),
 112                             source: None,
 113                             docs: Default::default(),
 114                             links: Default::default(),
 115                             attrs: Default::default(),
 116                             deprecation: Default::default(),
 117                         },
 118                     ))
 119                 } else {
 120                     None
 121                 }
 122             })
 123             .collect()
 124     }
 125 }
 126
 127 impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
 128     fn descr() -> &'static str {
 129         "json"
 130     }
 131
 132     fn init(
 133         krate: clean::Crate,
 134         options: RenderOptions,
 135         _edition: Edition,
 136         cache: Cache,
 137         tcx: TyCtxt<'tcx>,
 138     ) -> Result<(Self, clean::Crate), Error> {
 139         debug!("Initializing json renderer");
 140         Ok((
 141             JsonRenderer {
 142                 tcx,
 143                 index: Rc::new(RefCell::new(FxHashMap::default())),
 144                 out_path: options.output,
 145                 cache: Rc::new(cache),
 146             },
 147             krate,
 148         ))
 149     }
 150
 151     /// Inserts an item into the index. This should be used rather than directly calling insert on
 152     /// the hashmap because certain items (traits and types) need to have their mappings for trait
 153     /// implementations filled out before they're inserted.
 154     fn item(&mut self, item: clean::Item) -> Result<(), Error> {
 155         // Flatten items that recursively store other items
 156         item.kind.inner_items().for_each(|i| self.item(i.clone()).unwrap());
 157
 158         let id = item.def_id;
 159         if let Some(mut new_item) = self.convert_item(item) {
 160             if let types::ItemEnum::Trait(ref mut t) = new_item.inner {
 161                 t.implementors = self.get_trait_implementors(id)
 162             } else if let types::ItemEnum::Struct(ref mut s) = new_item.inner {
 163                 s.impls = self.get_impls(id)
 164             } else if let types::ItemEnum::Enum(ref mut e) = new_item.inner {
 165                 e.impls = self.get_impls(id)
 166             }
 167             let removed = self.index.borrow_mut().insert(from_def_id(id), new_item.clone());
 168             // FIXME(adotinthevoid): Currently, the index is duplicated. This is a sanity check
 169             // to make sure the items are unique.
 170             if let Some(old_item) = removed {
 171                 assert_eq!(old_item, new_item);
 172             }
 173         }
 174
 175         Ok(())
 176     }
 177
 178     fn mod_item_in(&mut self, item: &clean::Item, _module_name: &str) -> Result<(), Error> {
 179         use clean::types::ItemKind::*;
 180         if let ModuleItem(m) = &*item.kind {
 181             for item in &m.items {
 182                 match &*item.kind {
 183                     // These don't have names so they don't get added to the output by default
 184                     ImportItem(_) => self.item(item.clone()).unwrap(),
 185                     ExternCrateItem { .. } => self.item(item.clone()).unwrap(),
 186                     ImplItem(i) => i.items.iter().for_each(|i| self.item(i.clone()).unwrap()),
 187                     _ => {}
 188                 }
 189             }
 190         }
 191         self.item(item.clone()).unwrap();
 192         Ok(())
 193     }
 194
 195     fn mod_item_out(&mut self, _item_name: &str) -> Result<(), Error> {
 196         Ok(())
 197     }
 198
 199     fn after_krate(
 200         &mut self,
 201         _krate: &clean::Crate,
 202         _diag: &rustc_errors::Handler,
 203     ) -> Result<(), Error> {
 204         debug!("Done with crate");
 205         let mut index = (*self.index).clone().into_inner();
 206         index.extend(self.get_trait_items());
 207         // This needs to be the default HashMap for compatibility with the public interface for
 208         // rustdoc-json
 209         #[allow(rustc::default_hash_types)]
 210         let output = types::Crate {
 211             root: types::Id(String::from("0:0")),
 212             crate_version: self.cache.crate_version.clone(),
 213             includes_private: self.cache.document_private,
 214             index: index.into_iter().collect(),
 215             paths: self
 216                 .cache
 217                 .paths
 218                 .clone()
 219                 .into_iter()
 220                 .chain(self.cache.external_paths.clone().into_iter())
 221                 .map(|(k, (path, kind))| {
 222                     (
 223                         from_def_id(k),
 224                         types::ItemSummary { crate_id: k.krate.as_u32(), path, kind: kind.into() },
 225                     )
 226                 })
 227                 .collect(),
 228             external_crates: self
 229                 .cache
 230                 .extern_locations
 231                 .iter()
 232                 .map(|(k, v)| {
 233                     (
 234                         k.as_u32(),
 235                         types::ExternalCrate {
 236                             name: v.0.to_string(),
 237                             html_root_url: match &v.2 {
 238                                 ExternalLocation::Remote(s) => Some(s.clone()),
 239                                 _ => None,
 240                             },
 241                         },
 242                     )
 243                 })
 244                 .collect(),
 245             format_version: 4,
 246         };
 247         let mut p = self.out_path.clone();
 248         p.push(output.index.get(&output.root).unwrap().name.clone().unwrap());
 249         p.set_extension("json");
 250         let file = File::create(&p).map_err(|error| Error { error: error.to_string(), file: p })?;
 251         serde_json::ser::to_writer(&file, &output).unwrap();
 252         Ok(())
 253     }
 254
 255     fn cache(&self) -> &Cache {
 256         &self.cache
 257     }
 258 }