rust/src/librustdoc/visit_ast.rs
Joshua Nelson 6dc4f7a9d4 Don't unnecessarily override attrs for Module
They were never changed from the default, which you can get with
`tcx.get_attrs()`.
2020-12-23 15:25:30 -05:00

336 lines
12 KiB
Rust

//! The Rust AST Visitor. Extracts useful information and massages it into a form
//! usable for `clean`.
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_hir as hir;
use rustc_hir::def::{DefKind, Res};
use rustc_hir::def_id::DefId;
use rustc_hir::Node;
use rustc_middle::middle::privacy::AccessLevel;
use rustc_middle::ty::TyCtxt;
use rustc_span::source_map::Spanned;
use rustc_span::symbol::{kw, sym, Symbol};
use rustc_span::{self, Span};
use std::mem;
use crate::clean::{self, AttributesExt, NestedAttributesExt};
use crate::core;
use crate::doctree::*;
// FIXME: Should this be replaced with tcx.def_path_str?
fn def_id_to_path(tcx: TyCtxt<'_>, did: DefId) -> Vec<String> {
let crate_name = tcx.crate_name(did.krate).to_string();
let relative = tcx.def_path(did).data.into_iter().filter_map(|elem| {
// extern blocks have an empty name
let s = elem.data.to_string();
if !s.is_empty() { Some(s) } else { None }
});
std::iter::once(crate_name).chain(relative).collect()
}
// Also, is there some reason that this doesn't use the 'visit'
// framework from syntax?.
crate struct RustdocVisitor<'a, 'tcx> {
cx: &'a mut core::DocContext<'tcx>,
view_item_stack: FxHashSet<hir::HirId>,
inlining: bool,
/// Are the current module and all of its parents public?
inside_public_path: bool,
exact_paths: FxHashMap<DefId, Vec<String>>,
}
impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
crate fn new(cx: &'a mut core::DocContext<'tcx>) -> RustdocVisitor<'a, 'tcx> {
// If the root is re-exported, terminate all recursion.
let mut stack = FxHashSet::default();
stack.insert(hir::CRATE_HIR_ID);
RustdocVisitor {
cx,
view_item_stack: stack,
inlining: false,
inside_public_path: true,
exact_paths: FxHashMap::default(),
}
}
fn store_path(&mut self, did: DefId) {
let tcx = self.cx.tcx;
self.exact_paths.entry(did).or_insert_with(|| def_id_to_path(tcx, did));
}
crate fn visit(mut self, krate: &'tcx hir::Crate<'_>) -> Module<'tcx> {
let mut module = self.visit_mod_contents(
krate.item.span,
&Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Public },
hir::CRATE_HIR_ID,
&krate.item.module,
None,
);
// Attach the crate's exported macros to the top-level module:
module.macros.extend(krate.exported_macros.iter().map(|def| (def, None)));
module.is_crate = true;
self.cx.renderinfo.get_mut().exact_paths = self.exact_paths;
module
}
fn visit_mod_contents(
&mut self,
span: Span,
vis: &'tcx hir::Visibility<'_>,
id: hir::HirId,
m: &'tcx hir::Mod<'tcx>,
name: Option<Symbol>,
) -> Module<'tcx> {
let mut om = Module::new(name);
om.where_outer = span;
om.where_inner = m.inner;
om.id = id;
// Keep track of if there were any private modules in the path.
let orig_inside_public_path = self.inside_public_path;
self.inside_public_path &= vis.node.is_pub();
for i in m.item_ids {
let item = self.cx.tcx.hir().expect_item(i.id);
self.visit_item(item, None, &mut om);
}
self.inside_public_path = orig_inside_public_path;
om
}
/// Tries to resolve the target of a `crate use` statement and inlines the
/// target if it is defined locally and would not be documented otherwise,
/// or when it is specifically requested with `please_inline`.
/// (the latter is the case when the import is marked `doc(inline)`)
///
/// Cross-crate inlining occurs later on during crate cleaning
/// and follows different rules.
///
/// Returns `true` if the target has been inlined.
fn maybe_inline_local(
&mut self,
id: hir::HirId,
res: Res,
renamed: Option<Symbol>,
glob: bool,
om: &mut Module<'tcx>,
please_inline: bool,
) -> bool {
fn inherits_doc_hidden(cx: &core::DocContext<'_>, mut node: hir::HirId) -> bool {
while let Some(id) = cx.tcx.hir().get_enclosing_scope(node) {
node = id;
if cx.tcx.hir().attrs(node).lists(sym::doc).has_word(sym::hidden) {
return true;
}
if node == hir::CRATE_HIR_ID {
break;
}
}
false
}
debug!("maybe_inline_local res: {:?}", res);
let tcx = self.cx.tcx;
let res_did = if let Some(did) = res.opt_def_id() {
did
} else {
return false;
};
let use_attrs = tcx.hir().attrs(id);
// Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
|| use_attrs.lists(sym::doc).has_word(sym::hidden);
// For cross-crate impl inlining we need to know whether items are
// reachable in documentation -- a previously nonreachable item can be
// made reachable by cross-crate inlining which we're checking here.
// (this is done here because we need to know this upfront).
if !res_did.is_local() && !is_no_inline {
let attrs = clean::inline::load_attrs(self.cx, res_did);
let self_is_hidden = attrs.lists(sym::doc).has_word(sym::hidden);
if !self_is_hidden {
if let Res::Def(kind, did) = res {
if kind == DefKind::Mod {
crate::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did)
} else {
// All items need to be handled here in case someone wishes to link
// to them with intra-doc links
self.cx
.renderinfo
.get_mut()
.access_levels
.map
.insert(did, AccessLevel::Public);
}
}
}
return false;
}
let res_hir_id = match res_did.as_local() {
Some(n) => tcx.hir().local_def_id_to_hir_id(n),
None => return false,
};
let is_private = !self.cx.renderinfo.borrow().access_levels.is_public(res_did);
let is_hidden = inherits_doc_hidden(self.cx, res_hir_id);
// Only inline if requested or if the item would otherwise be stripped.
if (!please_inline && !is_private && !is_hidden) || is_no_inline {
return false;
}
if !self.view_item_stack.insert(res_hir_id) {
return false;
}
let ret = match tcx.hir().get(res_hir_id) {
Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
let prev = mem::replace(&mut self.inlining, true);
for i in m.item_ids {
let i = self.cx.tcx.hir().expect_item(i.id);
self.visit_item(i, None, om);
}
self.inlining = prev;
true
}
Node::Item(it) if !glob => {
let prev = mem::replace(&mut self.inlining, true);
self.visit_item(it, renamed, om);
self.inlining = prev;
true
}
Node::ForeignItem(it) if !glob => {
let prev = mem::replace(&mut self.inlining, true);
self.visit_foreign_item(it, renamed, om);
self.inlining = prev;
true
}
Node::MacroDef(def) if !glob => {
om.macros.push((def, renamed));
true
}
_ => false,
};
self.view_item_stack.remove(&res_hir_id);
ret
}
fn visit_item(
&mut self,
item: &'tcx hir::Item<'_>,
renamed: Option<Symbol>,
om: &mut Module<'tcx>,
) {
debug!("visiting item {:?}", item);
let name = renamed.unwrap_or(item.ident.name);
if item.vis.node.is_pub() {
let def_id = self.cx.tcx.hir().local_def_id(item.hir_id);
self.store_path(def_id.to_def_id());
}
match item.kind {
hir::ItemKind::ForeignMod { items, .. } => {
for item in items {
let item = self.cx.tcx.hir().foreign_item(item.id);
self.visit_foreign_item(item, None, om);
}
}
// If we're inlining, skip private items.
_ if self.inlining && !item.vis.node.is_pub() => {}
hir::ItemKind::GlobalAsm(..) => {}
hir::ItemKind::Use(_, hir::UseKind::ListStem) => {}
hir::ItemKind::Use(ref path, kind) => {
let is_glob = kind == hir::UseKind::Glob;
// Struct and variant constructors and proc macro stubs always show up alongside
// their definitions, we've already processed them so just discard these.
if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = path.res {
return;
}
// If there was a private module in the current path then don't bother inlining
// anything as it will probably be stripped anyway.
if item.vis.node.is_pub() && self.inside_public_path {
let please_inline = item.attrs.iter().any(|item| match item.meta_item_list() {
Some(ref list) if item.has_name(sym::doc) => {
list.iter().any(|i| i.has_name(sym::inline))
}
_ => false,
});
let ident = if is_glob { None } else { Some(name) };
if self.maybe_inline_local(
item.hir_id,
path.res,
ident,
is_glob,
om,
please_inline,
) {
return;
}
}
om.imports.push(Import {
name,
id: item.hir_id,
vis: &item.vis,
attrs: &item.attrs,
path,
glob: is_glob,
span: item.span,
});
}
hir::ItemKind::Mod(ref m) => {
om.mods.push(self.visit_mod_contents(
item.span,
&item.vis,
item.hir_id,
m,
Some(name),
));
}
hir::ItemKind::Fn(..)
| hir::ItemKind::ExternCrate(..)
| hir::ItemKind::Enum(..)
| hir::ItemKind::Struct(..)
| hir::ItemKind::Union(..)
| hir::ItemKind::TyAlias(..)
| hir::ItemKind::OpaqueTy(..)
| hir::ItemKind::Static(..)
| hir::ItemKind::Trait(..)
| hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed)),
hir::ItemKind::Const(..) => {
// Underscore constants do not correspond to a nameable item and
// so are never useful in documentation.
if name != kw::Underscore {
om.items.push((item, renamed));
}
}
hir::ItemKind::Impl { ref of_trait, .. } => {
// Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
// them up regardless of where they're located.
if !self.inlining && of_trait.is_none() {
om.items.push((item, None));
}
}
}
}
fn visit_foreign_item(
&mut self,
item: &'tcx hir::ForeignItem<'_>,
renamed: Option<Symbol>,
om: &mut Module<'tcx>,
) {
// If inlining we only want to include public functions.
if !self.inlining || item.vis.node.is_pub() {
om.foreigns.push((item, renamed));
}
}
}