Auto merge of #149936 - yotamofek:pr/rustdoc/join_path_syms_lazy, r=<try>

`join_path_syms_lazy`

Author: rust-bors[bot]

src/librustdoc/html/format.rs

@@ -14,7 +14,6 @@ use std::slice;
 
 use itertools::{Either, Itertools};
 use rustc_abi::ExternAbi;
-use rustc_ast::join_path_syms;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, MacroKinds};
@@ -37,6 +36,15 @@ use crate::html::escape::{Escape, EscapeBodyText};
 use crate::html::render::Context;
 use crate::passes::collect_intra_doc_links::UrlFragment;
 
+pub(crate) fn join_path_syms_lazy(path: &[Symbol]) -> impl Display + '_ {
+    fmt::from_fn(move |f| {
+        path.iter()
+            .copied()
+            .map(|seg| Some(seg).filter(|seg| *seg != kw::PathRoot).maybe_display())
+            .joined("::", f)
+    })
+}
+
 pub(crate) fn print_generic_bounds(
     bounds: &[clean::GenericBound],
     cx: &Context<'_>,
@@ -674,7 +682,7 @@ pub(crate) fn link_tooltip(
             write!(f, "{}", cx.tcx().item_name(id))?;
         } else if !fqp.is_empty() {
             write!(f, "{shortty} ")?;
-            write!(f, "{}", join_path_syms(fqp))?;
+            write!(f, "{}", join_path_syms_lazy(fqp))?;
         }
         Ok(())
     })
@@ -705,7 +713,7 @@ fn resolved_path(
                     write!(
                         f,
                         "{path}::{anchor}",
-                        path = join_path_syms(&rust_path[..rust_path.len() - 1]),
+                        path = join_path_syms_lazy(&rust_path[..rust_path.len() - 1]),
                         anchor = print_anchor(did, *rust_path.last().unwrap(), cx)
                     )
                 } else {
@@ -863,7 +871,7 @@ pub(crate) fn print_anchor(did: DefId, text: Symbol, cx: &Context<'_>) -> impl D
                 f,
                 r#"<a class="{kind}" href="{url}{anchor}" title="{kind} {path}">{text}</a>"#,
                 anchor = fragment(did, cx.tcx()),
-                path = join_path_syms(rust_path),
+                path = join_path_syms_lazy(&rust_path),
                 text = EscapeBodyText(text.as_str()),
             )
         } else {
@@ -1097,7 +1105,7 @@ fn print_qpath_data(qpath_data: &clean::QPathData, cx: &Context<'_>) -> impl Dis
                                 title=\"type {path}::{name}\">{name}</a>",
                     shortty = ItemType::AssocType,
                     name = assoc.name,
-                    path = join_path_syms(rust_path),
+                    path = join_path_syms_lazy(&rust_path),
                 )
             } else {
                 write!(f, "{}", assoc.name)

src/librustdoc/html/render/context.rs

@@ -6,7 +6,6 @@ use std::path::{Path, PathBuf};
 use std::sync::mpsc::{Receiver, channel};
 
 use askama::Template;
-use rustc_ast::join_path_syms;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_hir::Attribute;
 use rustc_hir::attrs::AttributeKind;
@@ -30,6 +29,7 @@ use crate::formats::FormatRenderer;
 use crate::formats::cache::Cache;
 use crate::formats::item_type::ItemType;
 use crate::html::escape::Escape;
+use crate::html::format::join_path_syms_lazy;
 use crate::html::macro_expansion::ExpandedCode;
 use crate::html::markdown::{self, ErrorCodes, IdMap, plain_text_summary};
 use crate::html::render::span_map::Span;
@@ -228,7 +228,7 @@ impl<'tcx> Context<'tcx> {
                     title.push_str(" in ");
                 }
                 // No need to include the namespace for primitive types and keywords
-                title.push_str(&join_path_syms(&self.current));
+                write!(title, "{}", join_path_syms_lazy(&self.current)).unwrap();
             };
             title.push_str(" - Rust");
             let tyname = it.type_();

src/librustdoc/html/render/print_item.rs

@@ -31,9 +31,9 @@ use crate::formats::Impl;
 use crate::formats::item_type::ItemType;
 use crate::html::escape::{Escape, EscapeBodyTextWithWbr};
 use crate::html::format::{
-    Ending, PrintWithSpace, full_print_fn_decl, print_abi_with_space, print_constness_with_space,
-    print_generic_bound, print_generics, print_impl, print_import, print_type, print_where_clause,
-    visibility_print_with_space,
+    Ending, PrintWithSpace, full_print_fn_decl, join_path_syms_lazy, print_abi_with_space,
+    print_constness_with_space, print_generic_bound, print_generics, print_impl, print_import,
+    print_type, print_where_clause, visibility_print_with_space,
 };
 use crate::html::markdown::{HeadingOffset, MarkdownSummaryLine};
 use crate::html::render::sidebar::filters;
@@ -1451,7 +1451,7 @@ fn item_type_alias(cx: &Context<'_>, it: &clean::Item, t: &clean::TypeAlias) ->
                 iter::repeat_n("..", cx.current.len()).chain(iter::once("type.impl")).collect();
             js_src_path.extend(target_fqp[..target_fqp.len() - 1].iter().copied());
             js_src_path.push_fmt(format_args!("{target_type}.{}.js", target_fqp.last().unwrap()));
-            let self_path = join_path_syms(self_fqp);
+            let self_path = join_path_syms_lazy(self_fqp);
             write!(
                 w,
                 "<script src=\"{src}\" data-self-path=\"{self_path}\" async></script>",

src/librustdoc/html/render/search_index.rs

@@ -10,7 +10,6 @@ use std::{io, iter};
 use ::serde::de::{self, Deserializer, Error as _};
 use ::serde::ser::{SerializeSeq, Serializer};
 use ::serde::{Deserialize, Serialize};
-use rustc_ast::join_path_syms;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_data_structures::thin_vec::ThinVec;
 use rustc_hir::attrs::AttributeKind;
@@ -28,6 +27,7 @@ use crate::config::ShouldMerge;
 use crate::error::Error;
 use crate::formats::cache::{Cache, OrphanImplItem};
 use crate::formats::item_type::ItemType;
+use crate::html::format::join_path_syms_lazy;
 use crate::html::markdown::short_markdown_summary;
 use crate::html::render::{self, IndexItem, IndexItemFunctionType, RenderType, RenderTypeId};
 
@@ -971,24 +971,27 @@ struct PathData {
     exact_module_path: Option<Vec<Symbol>>,
 }
 
+struct SerializedPath<'a>(&'a [Symbol]);
+
+impl<'a> Serialize for SerializedPath<'a> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.collect_str(&join_path_syms_lazy(self.0))
+    }
+}
+
 impl Serialize for PathData {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
         S: Serializer,
     {
         let mut seq = serializer.serialize_seq(None)?;
         seq.serialize_element(&self.ty)?;
-        seq.serialize_element(&if self.module_path.is_empty() {
-            String::new()
-        } else {
-            join_path_syms(&self.module_path)
-        })?;
-        if let Some(ref path) = self.exact_module_path {
-            seq.serialize_element(&if path.is_empty() {
-                String::new()
-            } else {
-                join_path_syms(path)
-            })?;
+        seq.serialize_element(&SerializedPath(&self.module_path))?;
+        if let Some(path) = &self.exact_module_path {
+            seq.serialize_element(&SerializedPath(path))?;
         }
         seq.end()
     }