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 pub mod types;
   9
  10 use std::cell::RefCell;
  11 use std::fs::File;
  12 use std::path::PathBuf;
  13 use std::rc::Rc;
  14
  15 use rustc_data_structures::fx::FxHashMap;
  16 use rustc_middle::ty::TyCtxt;
  17 use rustc_session::Session;
  18 use rustc_span::edition::Edition;
  19
  20 use crate::clean;
  21 use crate::config::{RenderInfo, RenderOptions};
  22 use crate::error::Error;
  23 use crate::formats::cache::Cache;
  24 use crate::formats::FormatRenderer;
  25 use crate::html::render::cache::ExternalLocation;
  26
  27 #[derive(Clone)]
  28 crate struct JsonRenderer<'tcx> {
  29     tcx: TyCtxt<'tcx>,
  30     /// A mapping of IDs that contains all local items for this crate which gets output as a top
  31     /// level field of the JSON blob.
  32     index: Rc<RefCell<FxHashMap<types::Id, types::Item>>>,
  33     /// The directory where the blob will be written to.
  34     out_path: PathBuf,
  35 }
  36
  37 impl JsonRenderer<'_> {
  38     fn sess(&self) -> &Session {
  39         self.tcx.sess
  40     }
  41
  42     fn get_trait_implementors(
  43         &mut self,
  44         id: rustc_span::def_id::DefId,
  45         cache: &Cache,
  46     ) -> Vec<types::Id> {
  47         cache
  48             .implementors
  49             .get(&id)
  50             .map(|implementors| {
  51                 implementors
  52                     .iter()
  53                     .map(|i| {
  54                         let item = &i.impl_item;
  55                         self.item(item.clone(), cache).unwrap();
  56                         item.def_id.into()
  57                     })
  58                     .collect()
  59             })
  60             .unwrap_or_default()
  61     }
  62
  63     fn get_impls(&mut self, id: rustc_span::def_id::DefId, cache: &Cache) -> Vec<types::Id> {
  64         cache
  65             .impls
  66             .get(&id)
  67             .map(|impls| {
  68                 impls
  69                     .iter()
  70                     .filter_map(|i| {
  71                         let item = &i.impl_item;
  72                         if item.def_id.is_local() {
  73                             self.item(item.clone(), cache).unwrap();
  74                             Some(item.def_id.into())
  75                         } else {
  76                             None
  77                         }
  78                     })
  79                     .collect()
  80             })
  81             .unwrap_or_default()
  82     }
  83
  84     fn get_trait_items(&mut self, cache: &Cache) -> Vec<(types::Id, types::Item)> {
  85         cache
  86             .traits
  87             .iter()
  88             .filter_map(|(&id, trait_item)| {
  89                 // only need to synthesize items for external traits
  90                 if !id.is_local() {
  91                     trait_item.items.clone().into_iter().for_each(|i| self.item(i, cache).unwrap());
  92                     Some((
  93                         id.into(),
  94                         types::Item {
  95                             id: id.into(),
  96                             crate_id: id.krate.as_u32(),
  97                             name: cache
  98                                 .paths
  99                                 .get(&id)
 100                                 .unwrap_or_else(|| {
 101                                     cache
 102                                         .external_paths
 103                                         .get(&id)
 104                                         .expect("Trait should either be in local or external paths")
 105                                 })
 106                                 .0
 107                                 .last()
 108                                 .map(Clone::clone),
 109                             visibility: types::Visibility::Public,
 110                             kind: types::ItemKind::Trait,
 111                             inner: types::ItemEnum::TraitItem(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         _render_info: RenderInfo,
 136         _edition: Edition,
 137         _cache: &mut Cache,
 138         tcx: TyCtxt<'tcx>,
 139     ) -> Result<(Self, clean::Crate), Error> {
 140         debug!("Initializing json renderer");
 141         Ok((
 142             JsonRenderer {
 143                 tcx,
 144                 index: Rc::new(RefCell::new(FxHashMap::default())),
 145                 out_path: options.output,
 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, cache: &Cache) -> Result<(), Error> {
 155         // Flatten items that recursively store other items
 156         item.kind.inner_items().for_each(|i| self.item(i.clone(), cache).unwrap());
 157
 158         let id = item.def_id;
 159         if let Some(mut new_item) = self.convert_item(item) {
 160             if let types::ItemEnum::TraitItem(ref mut t) = new_item.inner {
 161                 t.implementors = self.get_trait_implementors(id, cache)
 162             } else if let types::ItemEnum::StructItem(ref mut s) = new_item.inner {
 163                 s.impls = self.get_impls(id, cache)
 164             } else if let types::ItemEnum::EnumItem(ref mut e) = new_item.inner {
 165                 e.impls = self.get_impls(id, cache)
 166             }
 167             let removed = self.index.borrow_mut().insert(id.into(), 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(
 179         &mut self,
 180         item: &clean::Item,
 181         _module_name: &str,
 182         cache: &Cache,
 183     ) -> Result<(), Error> {
 184         use clean::types::ItemKind::*;
 185         if let ModuleItem(m) = &*item.kind {
 186             for item in &m.items {
 187                 match &*item.kind {
 188                     // These don't have names so they don't get added to the output by default
 189                     ImportItem(_) => self.item(item.clone(), cache).unwrap(),
 190                     ExternCrateItem(_, _) => self.item(item.clone(), cache).unwrap(),
 191                     ImplItem(i) => {
 192                         i.items.iter().for_each(|i| self.item(i.clone(), cache).unwrap())
 193                     }
 194                     _ => {}
 195                 }
 196             }
 197         }
 198         self.item(item.clone(), cache).unwrap();
 199         Ok(())
 200     }
 201
 202     fn mod_item_out(&mut self, _item_name: &str) -> Result<(), Error> {
 203         Ok(())
 204     }
 205
 206     fn after_krate(
 207         &mut self,
 208         krate: &clean::Crate,
 209         cache: &Cache,
 210         _diag: &rustc_errors::Handler,
 211     ) -> Result<(), Error> {
 212         debug!("Done with crate");
 213         let mut index = (*self.index).clone().into_inner();
 214         index.extend(self.get_trait_items(cache));
 215         let output = types::Crate {
 216             root: types::Id(String::from("0:0")),
 217             crate_version: krate.version.clone(),
 218             includes_private: cache.document_private,
 219             index,
 220             paths: cache
 221                 .paths
 222                 .clone()
 223                 .into_iter()
 224                 .chain(cache.external_paths.clone().into_iter())
 225                 .map(|(k, (path, kind))| {
 226                     (
 227                         k.into(),
 228                         types::ItemSummary { crate_id: k.krate.as_u32(), path, kind: kind.into() },
 229                     )
 230                 })
 231                 .collect(),
 232             external_crates: cache
 233                 .extern_locations
 234                 .iter()
 235                 .map(|(k, v)| {
 236                     (
 237                         k.as_u32(),
 238                         types::ExternalCrate {
 239                             name: v.0.to_string(),
 240                             html_root_url: match &v.2 {
 241                                 ExternalLocation::Remote(s) => Some(s.clone()),
 242                                 _ => None,
 243                             },
 244                         },
 245                     )
 246                 })
 247                 .collect(),
 248             format_version: 2,
 249         };
 250         let mut p = self.out_path.clone();
 251         p.push(output.index.get(&output.root).unwrap().name.clone().unwrap());
 252         p.set_extension("json");
 253         let file = File::create(&p).map_err(|error| Error { error: error.to_string(), file: p })?;
 254         serde_json::ser::to_writer(&file, &output).unwrap();
 255         Ok(())
 256     }
 257 }