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use crate::clean::{self, GetDefId, AttributesExt};
use crate::fold::DocFolder;
use rustc::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefId};
use rustc::middle::privacy::AccessLevels;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use std::mem;
use std::path::{Path, PathBuf};
use std::collections::BTreeMap;
use syntax::source_map::FileName;
use syntax::symbol::sym;
use serialize::json::{ToJson, Json, as_json};
use super::{ItemType, IndexItem, IndexItemFunctionType, Impl, shorten, plain_summary_line};
use super::{Type, RenderInfo};
/// Indicates where an external crate can be found.
pub enum ExternalLocation {
/// Remote URL root of the external crate
Remote(String),
/// This external crate can be found in the local doc/ folder
Local,
/// The external crate could not be found.
Unknown,
}
/// This cache is used to store information about the `clean::Crate` being
/// rendered in order to provide more useful documentation. This contains
/// information like all implementors of a trait, all traits a type implements,
/// documentation for all known traits, etc.
///
/// This structure purposefully does not implement `Clone` because it's intended
/// to be a fairly large and expensive structure to clone. Instead this adheres
/// to `Send` so it may be stored in a `Arc` instance and shared among the various
/// rendering threads.
#[derive(Default)]
crate struct Cache {
/// Maps a type ID to all known implementations for that type. This is only
/// recognized for intra-crate `ResolvedPath` types, and is used to print
/// out extra documentation on the page of an enum/struct.
///
/// The values of the map are a list of implementations and documentation
/// found on that implementation.
pub impls: FxHashMap<DefId, Vec<Impl>>,
/// Maintains a mapping of local crate `NodeId`s to the fully qualified name
/// and "short type description" of that node. This is used when generating
/// URLs when a type is being linked to. External paths are not located in
/// this map because the `External` type itself has all the information
/// necessary.
pub paths: FxHashMap<DefId, (Vec<String>, ItemType)>,
/// Similar to `paths`, but only holds external paths. This is only used for
/// generating explicit hyperlinks to other crates.
pub external_paths: FxHashMap<DefId, (Vec<String>, ItemType)>,
/// Maps local `DefId`s of exported types to fully qualified paths.
/// Unlike 'paths', this mapping ignores any renames that occur
/// due to 'use' statements.
///
/// This map is used when writing out the special 'implementors'
/// javascript file. By using the exact path that the type
/// is declared with, we ensure that each path will be identical
/// to the path used if the corresponding type is inlined. By
/// doing this, we can detect duplicate impls on a trait page, and only display
/// the impl for the inlined type.
pub exact_paths: FxHashMap<DefId, Vec<String>>,
/// This map contains information about all known traits of this crate.
/// Implementations of a crate should inherit the documentation of the
/// parent trait if no extra documentation is specified, and default methods
/// should show up in documentation about trait implementations.
pub traits: FxHashMap<DefId, clean::Trait>,
/// When rendering traits, it's often useful to be able to list all
/// implementors of the trait, and this mapping is exactly, that: a mapping
/// of trait ids to the list of known implementors of the trait
pub implementors: FxHashMap<DefId, Vec<Impl>>,
/// Cache of where external crate documentation can be found.
pub extern_locations: FxHashMap<CrateNum, (String, PathBuf, ExternalLocation)>,
/// Cache of where documentation for primitives can be found.
pub primitive_locations: FxHashMap<clean::PrimitiveType, DefId>,
// Note that external items for which `doc(hidden)` applies to are shown as
// non-reachable while local items aren't. This is because we're reusing
// the access levels from the privacy check pass.
pub access_levels: AccessLevels<DefId>,
/// The version of the crate being documented, if given from the `--crate-version` flag.
pub crate_version: Option<String>,
// Private fields only used when initially crawling a crate to build a cache
stack: Vec<String>,
parent_stack: Vec<DefId>,
parent_is_trait_impl: bool,
search_index: Vec<IndexItem>,
stripped_mod: bool,
pub deref_trait_did: Option<DefId>,
pub deref_mut_trait_did: Option<DefId>,
pub owned_box_did: Option<DefId>,
masked_crates: FxHashSet<CrateNum>,
// In rare case where a structure is defined in one module but implemented
// in another, if the implementing module is parsed before defining module,
// then the fully qualified name of the structure isn't presented in `paths`
// yet when its implementation methods are being indexed. Caches such methods
// and their parent id here and indexes them at the end of crate parsing.
orphan_impl_items: Vec<(DefId, clean::Item)>,
// Similarly to `orphan_impl_items`, sometimes trait impls are picked up
// even though the trait itself is not exported. This can happen if a trait
// was defined in function/expression scope, since the impl will be picked
// up by `collect-trait-impls` but the trait won't be scraped out in the HIR
// crawl. In order to prevent crashes when looking for spotlight traits or
// when gathering trait documentation on a type, hold impls here while
// folding and add them to the cache later on if we find the trait.
orphan_trait_impls: Vec<(DefId, FxHashSet<DefId>, Impl)>,
/// Aliases added through `#[doc(alias = "...")]`. Since a few items can have the same alias,
/// we need the alias element to have an array of items.
pub(super) aliases: FxHashMap<String, Vec<IndexItem>>,
}
impl Cache {
pub fn from_krate(
renderinfo: RenderInfo,
extern_html_root_urls: &BTreeMap<String, String>,
dst: &Path,
mut krate: clean::Crate,
) -> (clean::Crate, String, Cache) {
// Crawl the crate to build various caches used for the output
let RenderInfo {
inlined: _,
external_paths,
exact_paths,
access_levels,
deref_trait_did,
deref_mut_trait_did,
owned_box_did,
} = renderinfo;
let external_paths = external_paths.into_iter()
.map(|(k, (v, t))| (k, (v, ItemType::from(t))))
.collect();
let mut cache = Cache {
impls: Default::default(),
external_paths,
exact_paths,
paths: Default::default(),
implementors: Default::default(),
stack: Vec::new(),
parent_stack: Vec::new(),
search_index: Vec::new(),
parent_is_trait_impl: false,
extern_locations: Default::default(),
primitive_locations: Default::default(),
stripped_mod: false,
access_levels,
crate_version: krate.version.take(),
orphan_impl_items: Vec::new(),
orphan_trait_impls: Vec::new(),
traits: krate.external_traits.replace(Default::default()),
deref_trait_did,
deref_mut_trait_did,
owned_box_did,
masked_crates: mem::take(&mut krate.masked_crates),
aliases: Default::default(),
};
// Cache where all our extern crates are located
for &(n, ref e) in &krate.externs {
let src_root = match e.src {
FileName::Real(ref p) => match p.parent() {
Some(p) => p.to_path_buf(),
None => PathBuf::new(),
},
_ => PathBuf::new(),
};
let extern_url = extern_html_root_urls.get(&e.name).map(|u| &**u);
cache.extern_locations.insert(n, (e.name.clone(), src_root,
extern_location(e, extern_url, &dst)));
let did = DefId { krate: n, index: CRATE_DEF_INDEX };
cache.external_paths.insert(did, (vec![e.name.to_string()], ItemType::Module));
}
// Cache where all known primitives have their documentation located.
//
// Favor linking to as local extern as possible, so iterate all crates in
// reverse topological order.
for &(_, ref e) in krate.externs.iter().rev() {
for &(def_id, prim, _) in &e.primitives {
cache.primitive_locations.insert(prim, def_id);
}
}
for &(def_id, prim, _) in &krate.primitives {
cache.primitive_locations.insert(prim, def_id);
}
cache.stack.push(krate.name.clone());
krate = cache.fold_crate(krate);
for (trait_did, dids, impl_) in cache.orphan_trait_impls.drain(..) {
if cache.traits.contains_key(&trait_did) {
for did in dids {
cache.impls.entry(did).or_insert(vec![]).push(impl_.clone());
}
}
}
// Build our search index
let index = build_index(&krate, &mut cache);
(krate, index, cache)
}
}
impl DocFolder for Cache {
fn fold_item(&mut self, item: clean::Item) -> Option<clean::Item> {
if item.def_id.is_local() {
debug!("folding {} \"{:?}\", id {:?}", item.type_(), item.name, item.def_id);
}
// If this is a stripped module,
// we don't want it or its children in the search index.
let orig_stripped_mod = match item.inner {
clean::StrippedItem(box clean::ModuleItem(..)) => {
mem::replace(&mut self.stripped_mod, true)
}
_ => self.stripped_mod,
};
// If the impl is from a masked crate or references something from a
// masked crate then remove it completely.
if let clean::ImplItem(ref i) = item.inner {
if self.masked_crates.contains(&item.def_id.krate) ||
i.trait_.def_id().map_or(false, |d| self.masked_crates.contains(&d.krate)) ||
i.for_.def_id().map_or(false, |d| self.masked_crates.contains(&d.krate)) {
return None;
}
}
// Propagate a trait method's documentation to all implementors of the
// trait.
if let clean::TraitItem(ref t) = item.inner {
self.traits.entry(item.def_id).or_insert_with(|| t.clone());
}
// Collect all the implementors of traits.
if let clean::ImplItem(ref i) = item.inner {
if let Some(did) = i.trait_.def_id() {
if i.blanket_impl.is_none() {
self.implementors.entry(did).or_default().push(Impl {
impl_item: item.clone(),
});
}
}
}
// Index this method for searching later on.
if let Some(ref s) = item.name {
let (parent, is_inherent_impl_item) = match item.inner {
clean::StrippedItem(..) => ((None, None), false),
clean::AssocConstItem(..) |
clean::TypedefItem(_, true) if self.parent_is_trait_impl => {
// skip associated items in trait impls
((None, None), false)
}
clean::AssocTypeItem(..) |
clean::TyMethodItem(..) |
clean::StructFieldItem(..) |
clean::VariantItem(..) => {
((Some(*self.parent_stack.last().unwrap()),
Some(&self.stack[..self.stack.len() - 1])),
false)
}
clean::MethodItem(..) | clean::AssocConstItem(..) => {
if self.parent_stack.is_empty() {
((None, None), false)
} else {
let last = self.parent_stack.last().unwrap();
let did = *last;
let path = match self.paths.get(&did) {
// The current stack not necessarily has correlation
// for where the type was defined. On the other
// hand, `paths` always has the right
// information if present.
Some(&(ref fqp, ItemType::Trait)) |
Some(&(ref fqp, ItemType::Struct)) |
Some(&(ref fqp, ItemType::Union)) |
Some(&(ref fqp, ItemType::Enum)) =>
Some(&fqp[..fqp.len() - 1]),
Some(..) => Some(&*self.stack),
None => None
};
((Some(*last), path), true)
}
}
_ => ((None, Some(&*self.stack)), false)
};
match parent {
(parent, Some(path)) if is_inherent_impl_item || (!self.stripped_mod) => {
debug_assert!(!item.is_stripped());
// A crate has a module at its root, containing all items,
// which should not be indexed. The crate-item itself is
// inserted later on when serializing the search-index.
if item.def_id.index != CRATE_DEF_INDEX {
self.search_index.push(IndexItem {
ty: item.type_(),
name: s.to_string(),
path: path.join("::"),
desc: shorten(plain_summary_line(item.doc_value())),
parent,
parent_idx: None,
search_type: get_index_search_type(&item),
});
}
}
(Some(parent), None) if is_inherent_impl_item => {
// We have a parent, but we don't know where they're
// defined yet. Wait for later to index this item.
self.orphan_impl_items.push((parent, item.clone()));
}
_ => {}
}
}
// Keep track of the fully qualified path for this item.
let pushed = match item.name {
Some(ref n) if !n.is_empty() => {
self.stack.push(n.to_string());
true
}
_ => false,
};
match item.inner {
clean::StructItem(..) | clean::EnumItem(..) |
clean::TypedefItem(..) | clean::TraitItem(..) |
clean::FunctionItem(..) | clean::ModuleItem(..) |
clean::ForeignFunctionItem(..) | clean::ForeignStaticItem(..) |
clean::ConstantItem(..) | clean::StaticItem(..) |
clean::UnionItem(..) | clean::ForeignTypeItem |
clean::MacroItem(..) | clean::ProcMacroItem(..)
if !self.stripped_mod => {
// Re-exported items mean that the same id can show up twice
// in the rustdoc ast that we're looking at. We know,
// however, that a re-exported item doesn't show up in the
// `public_items` map, so we can skip inserting into the
// paths map if there was already an entry present and we're
// not a public item.
if !self.paths.contains_key(&item.def_id) ||
self.access_levels.is_public(item.def_id)
{
self.paths.insert(item.def_id,
(self.stack.clone(), item.type_()));
}
self.add_aliases(&item);
}
// Link variants to their parent enum because pages aren't emitted
// for each variant.
clean::VariantItem(..) if !self.stripped_mod => {
let mut stack = self.stack.clone();
stack.pop();
self.paths.insert(item.def_id, (stack, ItemType::Enum));
}
clean::PrimitiveItem(..) => {
self.add_aliases(&item);
self.paths.insert(item.def_id, (self.stack.clone(),
item.type_()));
}
_ => {}
}
// Maintain the parent stack
let orig_parent_is_trait_impl = self.parent_is_trait_impl;
let parent_pushed = match item.inner {
clean::TraitItem(..) | clean::EnumItem(..) | clean::ForeignTypeItem |
clean::StructItem(..) | clean::UnionItem(..) => {
self.parent_stack.push(item.def_id);
self.parent_is_trait_impl = false;
true
}
clean::ImplItem(ref i) => {
self.parent_is_trait_impl = i.trait_.is_some();
match i.for_ {
clean::ResolvedPath{ did, .. } => {
self.parent_stack.push(did);
true
}
ref t => {
let prim_did = t.primitive_type().and_then(|t| {
self.primitive_locations.get(&t).cloned()
});
match prim_did {
Some(did) => {
self.parent_stack.push(did);
true
}
None => false,
}
}
}
}
_ => false
};
// Once we've recursively found all the generics, hoard off all the
// implementations elsewhere.
let ret = self.fold_item_recur(item).and_then(|item| {
if let clean::Item { inner: clean::ImplItem(_), .. } = item {
// Figure out the id of this impl. This may map to a
// primitive rather than always to a struct/enum.
// Note: matching twice to restrict the lifetime of the `i` borrow.
let mut dids = FxHashSet::default();
if let clean::Item { inner: clean::ImplItem(ref i), .. } = item {
match i.for_ {
clean::ResolvedPath { did, .. } |
clean::BorrowedRef {
type_: box clean::ResolvedPath { did, .. }, ..
} => {
dids.insert(did);
}
ref t => {
let did = t.primitive_type().and_then(|t| {
self.primitive_locations.get(&t).cloned()
});
if let Some(did) = did {
dids.insert(did);
}
}
}
if let Some(generics) = i.trait_.as_ref().and_then(|t| t.generics()) {
for bound in generics {
if let Some(did) = bound.def_id() {
dids.insert(did);
}
}
}
} else {
unreachable!()
};
let impl_item = Impl {
impl_item: item,
};
if impl_item.trait_did().map_or(true, |d| self.traits.contains_key(&d)) {
for did in dids {
self.impls.entry(did).or_insert(vec![]).push(impl_item.clone());
}
} else {
let trait_did = impl_item.trait_did().unwrap();
self.orphan_trait_impls.push((trait_did, dids, impl_item));
}
None
} else {
Some(item)
}
});
if pushed { self.stack.pop().unwrap(); }
if parent_pushed { self.parent_stack.pop().unwrap(); }
self.stripped_mod = orig_stripped_mod;
self.parent_is_trait_impl = orig_parent_is_trait_impl;
ret
}
}
impl Cache {
fn add_aliases(&mut self, item: &clean::Item) {
if item.def_id.index == CRATE_DEF_INDEX {
return
}
if let Some(ref item_name) = item.name {
let path = self.paths.get(&item.def_id)
.map(|p| p.0[..p.0.len() - 1].join("::"))
.unwrap_or("std".to_owned());
for alias in item.attrs.lists(sym::doc)
.filter(|a| a.check_name(sym::alias))
.filter_map(|a| a.value_str()
.map(|s| s.to_string().replace("\"", "")))
.filter(|v| !v.is_empty())
.collect::<FxHashSet<_>>()
.into_iter() {
self.aliases.entry(alias)
.or_insert(Vec::with_capacity(1))
.push(IndexItem {
ty: item.type_(),
name: item_name.to_string(),
path: path.clone(),
desc: shorten(plain_summary_line(item.doc_value())),
parent: None,
parent_idx: None,
search_type: get_index_search_type(&item),
});
}
}
}
}
/// Attempts to find where an external crate is located, given that we're
/// rendering in to the specified source destination.
fn extern_location(e: &clean::ExternalCrate, extern_url: Option<&str>, dst: &Path)
-> ExternalLocation
{
use ExternalLocation::*;
// See if there's documentation generated into the local directory
let local_location = dst.join(&e.name);
if local_location.is_dir() {
return Local;
}
if let Some(url) = extern_url {
let mut url = url.to_string();
if !url.ends_with("/") {
url.push('/');
}
return Remote(url);
}
// Failing that, see if there's an attribute specifying where to find this
// external crate
e.attrs.lists(sym::doc)
.filter(|a| a.check_name(sym::html_root_url))
.filter_map(|a| a.value_str())
.map(|url| {
let mut url = url.to_string();
if !url.ends_with("/") {
url.push('/')
}
Remote(url)
}).next().unwrap_or(Unknown) // Well, at least we tried.
}
/// Builds the search index from the collected metadata
fn build_index(krate: &clean::Crate, cache: &mut Cache) -> String {
let mut nodeid_to_pathid = FxHashMap::default();
let mut crate_items = Vec::with_capacity(cache.search_index.len());
let mut crate_paths = Vec::<Json>::new();
let Cache { ref mut search_index,
ref orphan_impl_items,
ref paths, .. } = *cache;
// Attach all orphan items to the type's definition if the type
// has since been learned.
for &(did, ref item) in orphan_impl_items {
if let Some(&(ref fqp, _)) = paths.get(&did) {
search_index.push(IndexItem {
ty: item.type_(),
name: item.name.clone().unwrap(),
path: fqp[..fqp.len() - 1].join("::"),
desc: shorten(plain_summary_line(item.doc_value())),
parent: Some(did),
parent_idx: None,
search_type: get_index_search_type(&item),
});
}
}
// Reduce `NodeId` in paths into smaller sequential numbers,
// and prune the paths that do not appear in the index.
let mut lastpath = String::new();
let mut lastpathid = 0usize;
for item in search_index {
item.parent_idx = item.parent.map(|nodeid| {
if nodeid_to_pathid.contains_key(&nodeid) {
*nodeid_to_pathid.get(&nodeid).unwrap()
} else {
let pathid = lastpathid;
nodeid_to_pathid.insert(nodeid, pathid);
lastpathid += 1;
let &(ref fqp, short) = paths.get(&nodeid).unwrap();
crate_paths.push(((short as usize), fqp.last().unwrap().clone()).to_json());
pathid
}
});
// Omit the parent path if it is same to that of the prior item.
if lastpath == item.path {
item.path.clear();
} else {
lastpath = item.path.clone();
}
crate_items.push(item.to_json());
}
let crate_doc = krate.module.as_ref().map(|module| {
shorten(plain_summary_line(module.doc_value()))
}).unwrap_or(String::new());
let mut crate_data = BTreeMap::new();
crate_data.insert("doc".to_owned(), Json::String(crate_doc));
crate_data.insert("i".to_owned(), Json::Array(crate_items));
crate_data.insert("p".to_owned(), Json::Array(crate_paths));
// Collect the index into a string
format!("searchIndex[{}] = {};",
as_json(&krate.name),
Json::Object(crate_data))
}
fn get_index_search_type(item: &clean::Item) -> Option<IndexItemFunctionType> {
let (all_types, ret_types) = match item.inner {
clean::FunctionItem(ref f) => (&f.all_types, &f.ret_types),
clean::MethodItem(ref m) => (&m.all_types, &m.ret_types),
clean::TyMethodItem(ref m) => (&m.all_types, &m.ret_types),
_ => return None,
};
let inputs = all_types.iter().map(|arg| {
get_index_type(&arg)
}).filter(|a| a.name.is_some()).collect();
let output = ret_types.iter().map(|arg| {
get_index_type(&arg)
}).filter(|a| a.name.is_some()).collect::<Vec<_>>();
let output = if output.is_empty() {
None
} else {
Some(output)
};
Some(IndexItemFunctionType { inputs, output })
}
fn get_index_type(clean_type: &clean::Type) -> Type {
let t = Type {
name: get_index_type_name(clean_type, true).map(|s| s.to_ascii_lowercase()),
generics: get_generics(clean_type),
};
t
}
fn get_index_type_name(clean_type: &clean::Type, accept_generic: bool) -> Option<String> {
match *clean_type {
clean::ResolvedPath { ref path, .. } => {
let segments = &path.segments;
let path_segment = segments.into_iter().last().unwrap_or_else(|| panic!(
"get_index_type_name(clean_type: {:?}, accept_generic: {:?}) had length zero path",
clean_type, accept_generic
));
Some(path_segment.name.clone())
}
clean::Generic(ref s) if accept_generic => Some(s.clone()),
clean::Primitive(ref p) => Some(format!("{:?}", p)),
clean::BorrowedRef { ref type_, .. } => get_index_type_name(type_, accept_generic),
// FIXME: add all from clean::Type.
_ => None
}
}
fn get_generics(clean_type: &clean::Type) -> Option<Vec<String>> {
clean_type.generics()
.and_then(|types| {
let r = types.iter()
.filter_map(|t| get_index_type_name(t, false))
.map(|s| s.to_ascii_lowercase())
.collect::<Vec<_>>();
if r.is_empty() {
None
} else {
Some(r)
}
})
}
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