resolve: Optimize path resolution for rustdoc

Do not construct or pass unused data
This commit is contained in:
Vadim Petrochenkov 2022-03-24 00:03:12 +03:00
parent 0749ec67bc
commit 15a8b981e0
3 changed files with 38 additions and 92 deletions

View File

@ -71,7 +71,7 @@ use rustc_span::{Span, DUMMY_SP};
use smallvec::{smallvec, SmallVec};
use std::cell::{Cell, RefCell};
use std::collections::BTreeSet;
use std::{cmp, fmt, iter, mem, ptr};
use std::{cmp, fmt, mem, ptr};
use tracing::debug;
use diagnostics::{extend_span_to_previous_binding, find_span_of_binding_until_next_binding};
@ -3309,82 +3309,39 @@ impl<'a> Resolver<'a> {
})
}
/// Rustdoc uses this to resolve things in a recoverable way. `ResolutionError<'a>`
/// Rustdoc uses this to resolve doc link paths in a recoverable way. `PathResult<'a>`
/// isn't something that can be returned because it can't be made to live that long,
/// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
/// just that an error occurred.
// FIXME(Manishearth): intra-doc links won't get warned of epoch changes.
pub fn resolve_str_path_error(
pub fn resolve_rustdoc_path(
&mut self,
span: Span,
path_str: &str,
ns: Namespace,
module_id: DefId,
) -> Result<(ast::Path, Res), ()> {
let path = if path_str.starts_with("::") {
ast::Path {
span,
segments: iter::once(Ident::with_dummy_span(kw::PathRoot))
.chain(path_str.split("::").skip(1).map(Ident::from_str))
.map(|i| self.new_ast_path_segment(i))
.collect(),
tokens: None,
}
} else {
ast::Path {
span,
segments: path_str
.split("::")
.map(Ident::from_str)
.map(|i| self.new_ast_path_segment(i))
.collect(),
tokens: None,
}
};
let module = self.expect_module(module_id);
let parent_scope = &ParentScope::module(module, self);
let res = self.resolve_ast_path(&path, ns, parent_scope).map_err(|_| ())?;
Ok((path, res))
}
) -> Option<Res> {
let mut segments =
Vec::from_iter(path_str.split("::").map(Ident::from_str).map(Segment::from_ident));
if path_str.starts_with("::") {
segments[0].ident.name = kw::PathRoot;
}
// Resolve a path passed from rustdoc or HIR lowering.
fn resolve_ast_path(
&mut self,
path: &ast::Path,
ns: Namespace,
parent_scope: &ParentScope<'a>,
) -> Result<Res, (Span, ResolutionError<'a>)> {
let module = self.expect_module(module_id);
match self.resolve_path(
&Segment::from_path(path),
&segments,
Some(ns),
parent_scope,
path.span,
&ParentScope::module(module, self),
DUMMY_SP,
CrateLint::No,
) {
PathResult::Module(ModuleOrUniformRoot::Module(module)) => Ok(module.res().unwrap()),
PathResult::Module(ModuleOrUniformRoot::Module(module)) => Some(module.res().unwrap()),
PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => {
Ok(path_res.base_res())
Some(path_res.base_res())
}
PathResult::NonModule(..) => Err((
path.span,
ResolutionError::FailedToResolve {
label: String::from("type-relative paths are not supported in this context"),
suggestion: None,
},
)),
PathResult::NonModule(..) | PathResult::Failed { .. } => None,
PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
PathResult::Failed { span, label, suggestion, .. } => {
Err((span, ResolutionError::FailedToResolve { label, suggestion }))
}
}
}
fn new_ast_path_segment(&mut self, ident: Ident) -> ast::PathSegment {
let mut seg = ast::PathSegment::from_ident(ident);
seg.id = self.next_node_id();
seg
}
// For rustdoc.
pub fn graph_root(&self) -> Module<'a> {
self.graph_root

View File

@ -487,12 +487,10 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
module_id: DefId,
) -> Result<Res, ResolutionFailure<'a>> {
self.cx.enter_resolver(|resolver| {
// NOTE: this needs 2 separate lookups because `resolve_str_path_error` doesn't take
// NOTE: this needs 2 separate lookups because `resolve_rustdoc_path` doesn't take
// lexical scope into account (it ignores all macros not defined at the mod-level)
debug!("resolving {} as a macro in the module {:?}", path_str, module_id);
if let Ok((_, res)) =
resolver.resolve_str_path_error(DUMMY_SP, path_str, MacroNS, module_id)
{
if let Some(res) = resolver.resolve_rustdoc_path(path_str, MacroNS, module_id) {
// don't resolve builtins like `#[derive]`
if let Ok(res) = res.try_into() {
return Ok(res);
@ -540,10 +538,10 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
})
}
/// Convenience wrapper around `resolve_str_path_error`.
/// Convenience wrapper around `resolve_rustdoc_path`.
///
/// This also handles resolving `true` and `false` as booleans.
/// NOTE: `resolve_str_path_error` knows only about paths, not about types.
/// NOTE: `resolve_rustdoc_path` knows only about paths, not about types.
/// Associated items will never be resolved by this function.
fn resolve_path(
&self,
@ -556,18 +554,14 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
return res;
}
let result = self.cx.enter_resolver(|resolver| {
resolver
.resolve_str_path_error(DUMMY_SP, path_str, ns, module_id)
.and_then(|(_, res)| res.try_into())
});
// Resolver doesn't know about true, false, and types that aren't paths (e.g. `()`).
let result = self
.cx
.enter_resolver(|resolver| resolver.resolve_rustdoc_path(path_str, ns, module_id))
.and_then(|res| res.try_into().ok())
.or_else(|| resolve_primitive(path_str, ns));
debug!("{} resolved to {:?} in namespace {:?}", path_str, result, ns);
match result {
// resolver doesn't know about true, false, and types that aren't paths (e.g. `()`)
// manually as bool
Err(()) => resolve_primitive(path_str, ns),
Ok(res) => Some(res),
}
result
}
/// Resolves a string as a path within a particular namespace. Returns an

View File

@ -13,7 +13,7 @@ use rustc_hir::TraitCandidate;
use rustc_middle::ty::{DefIdTree, Visibility};
use rustc_resolve::{ParentScope, Resolver};
use rustc_session::config::Externs;
use rustc_span::{Span, SyntaxContext, DUMMY_SP};
use rustc_span::SyntaxContext;
use std::collections::hash_map::Entry;
use std::mem;
@ -39,7 +39,7 @@ crate fn early_resolve_intra_doc_links(
// Overridden `visit_item` below doesn't apply to the crate root,
// so we have to visit its attributes and reexports separately.
loader.load_links_in_attrs(&krate.attrs, krate.spans.inner_span);
loader.load_links_in_attrs(&krate.attrs);
loader.process_module_children_or_reexports(CRATE_DEF_ID.to_def_id());
visit::walk_crate(&mut loader, krate);
loader.add_foreign_traits_in_scope();
@ -49,12 +49,7 @@ crate fn early_resolve_intra_doc_links(
// DO NOT REMOVE THIS without first testing on the reproducer in
// https://github.com/jyn514/objr/commit/edcee7b8124abf0e4c63873e8422ff81beb11ebb
for (extern_name, _) in externs.iter().filter(|(_, entry)| entry.add_prelude) {
let _ = loader.resolver.resolve_str_path_error(
DUMMY_SP,
extern_name,
TypeNS,
CRATE_DEF_ID.to_def_id(),
);
loader.resolver.resolve_rustdoc_path(extern_name, TypeNS, CRATE_DEF_ID.to_def_id());
}
ResolverCaches {
@ -151,7 +146,7 @@ impl IntraLinkCrateLoader<'_, '_> {
}
}
fn load_links_in_attrs(&mut self, attrs: &[ast::Attribute], span: Span) {
fn load_links_in_attrs(&mut self, attrs: &[ast::Attribute]) {
// FIXME: this needs to consider reexport inlining.
let attrs = clean::Attributes::from_ast(attrs, None);
for (parent_module, doc) in attrs.collapsed_doc_value_by_module_level() {
@ -165,7 +160,7 @@ impl IntraLinkCrateLoader<'_, '_> {
} else {
continue;
};
let _ = self.resolver.resolve_str_path_error(span, &path_str, TypeNS, module_id);
self.resolver.resolve_rustdoc_path(&path_str, TypeNS, module_id);
}
}
}
@ -201,7 +196,7 @@ impl Visitor<'_> for IntraLinkCrateLoader<'_, '_> {
// loaded, even if the module itself has no doc comments.
self.add_traits_in_parent_scope(self.current_mod.to_def_id());
self.load_links_in_attrs(&item.attrs, item.span);
self.load_links_in_attrs(&item.attrs);
self.process_module_children_or_reexports(self.current_mod.to_def_id());
visit::walk_item(self, item);
@ -216,28 +211,28 @@ impl Visitor<'_> for IntraLinkCrateLoader<'_, '_> {
}
_ => {}
}
self.load_links_in_attrs(&item.attrs, item.span);
self.load_links_in_attrs(&item.attrs);
visit::walk_item(self, item);
}
}
fn visit_assoc_item(&mut self, item: &ast::AssocItem, ctxt: AssocCtxt) {
self.load_links_in_attrs(&item.attrs, item.span);
self.load_links_in_attrs(&item.attrs);
visit::walk_assoc_item(self, item, ctxt)
}
fn visit_foreign_item(&mut self, item: &ast::ForeignItem) {
self.load_links_in_attrs(&item.attrs, item.span);
self.load_links_in_attrs(&item.attrs);
visit::walk_foreign_item(self, item)
}
fn visit_variant(&mut self, v: &ast::Variant) {
self.load_links_in_attrs(&v.attrs, v.span);
self.load_links_in_attrs(&v.attrs);
visit::walk_variant(self, v)
}
fn visit_field_def(&mut self, field: &ast::FieldDef) {
self.load_links_in_attrs(&field.attrs, field.span);
self.load_links_in_attrs(&field.attrs);
visit::walk_field_def(self, field)
}