Rollup merge of #84601 - tdelabro:rustdoc-get-rid-of-cache-extern_locations, r=jyn514

rustdoc: Only store locations in Cache::extern_locations and calculate the other info on-demand

 help #84588

2 files changed, 11 insertions, 50 deletions

diff --git a/src/librustdoc/html/render/cache.rs b/src/librustdoc/html/render/cache.rs
index f4296a04e59..27a8065afb6 100644
--- a/src/librustdoc/html/render/cache.rs
+++ b/src/librustdoc/html/render/cache.rs
@@ -1,15 +1,13 @@
 use std::collections::BTreeMap;
-use std::path::Path;
 
-use rustc_ast::ast;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_middle::ty::TyCtxt;
-use rustc_span::symbol::{sym, Symbol};
+use rustc_span::symbol::Symbol;
 use serde::ser::{Serialize, SerializeStruct, Serializer};
 
 use crate::clean;
 use crate::clean::types::{
-    AttributesExt, FnDecl, FnRetTy, GenericBound, Generics, GetDefId, Type, WherePredicate,
+    FnDecl, FnRetTy, GenericBound, Generics, GetDefId, Type, WherePredicate,
 };
 use crate::formats::cache::Cache;
 use crate::formats::item_type::ItemType;
@@ -26,47 +24,6 @@ crate enum ExternalLocation {
     Unknown,
 }
 
-/// Attempts to find where an external crate is located, given that we're
-/// rendering in to the specified source destination.
-crate fn extern_location(
-    e: &clean::ExternalCrate,
-    extern_url: Option<&str>,
-    ast_attrs: &[ast::Attribute],
-    dst: &Path,
-    tcx: TyCtxt<'_>,
-) -> ExternalLocation {
-    use ExternalLocation::*;
-    // See if there's documentation generated into the local directory
-    let local_location = dst.join(&*e.name(tcx).as_str());
-    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
-    ast_attrs
-        .lists(sym::doc)
-        .filter(|a| a.has_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
 crate fn build_index<'tcx>(krate: &clean::Crate, cache: &mut Cache, tcx: TyCtxt<'tcx>) -> String {
     let mut defid_to_pathid = FxHashMap::default();
diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index 4c8ba0e7b49..293c0a40fa7 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -18,7 +18,7 @@ use super::print_item::{full_path, item_path, print_item};
 use super::write_shared::write_shared;
 use super::{print_sidebar, settings, AllTypes, NameDoc, StylePath, BASIC_KEYWORDS};
 
-use crate::clean;
+use crate::clean::{self, ExternalCrate};
 use crate::config::RenderOptions;
 use crate::docfs::{DocFS, PathError};
 use crate::error::Error;
@@ -304,12 +304,16 @@ impl<'tcx> Context<'tcx> {
             }
         } else {
             let (krate, src_root) = match *self.cache.extern_locations.get(&cnum)? {
-                (name, ref src, ExternalLocation::Local) => (name, src),
-                (name, ref src, ExternalLocation::Remote(ref s)) => {
+                ExternalLocation::Local => {
+                    let e = ExternalCrate { crate_num: cnum };
+                    (e.name(self.tcx()), e.src_root(self.tcx()))
+                }
+                ExternalLocation::Remote(ref s) => {
                     root = s.to_string();
-                    (name, src)
+                    let e = ExternalCrate { crate_num: cnum };
+                    (e.name(self.tcx()), e.src_root(self.tcx()))
                 }
-                (_, _, ExternalLocation::Unknown) => return None,
+                ExternalLocation::Unknown => return None,
             };
 
             sources::clean_path(&src_root, file, false, |component| {