Auto merge of #92526 - djc:rustdoc-askama, r=jsha

Migrate rustdoc from Tera to Askama

See #84419.

Should probably get a benchmarking run to verify if it has the intended effect on rustdoc performance.

cc `@jsha` `@jyn514.`

5 files changed, 7 insertions, 52 deletions

diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index 40453de8405..4f3455a9208 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -15,7 +15,6 @@ use rustc_span::symbol::sym;
 
 use super::print_item::{full_path, item_path, print_item};
 use super::search_index::build_index;
-use super::templates;
 use super::write_shared::write_shared;
 use super::{
     collect_spans_and_sources, print_sidebar, settings, AllTypes, LinkFromSrc, NameDoc, StylePath,
@@ -118,8 +117,6 @@ crate struct SharedContext<'tcx> {
     /// the crate.
     redirections: Option<RefCell<FxHashMap<String, String>>>,
 
-    pub(crate) templates: tera::Tera,
-
     /// Correspondance map used to link types used in the source code pages to allow to click on
     /// links to jump to the type's definition.
     crate span_correspondance_map: FxHashMap<rustc_span::Span, LinkFromSrc>,
@@ -218,11 +215,10 @@ impl<'tcx> Context<'tcx> {
 
         if !self.render_redirect_pages {
             layout::render(
-                &self.shared.templates,
                 &self.shared.layout,
                 &page,
                 |buf: &mut _| print_sidebar(self, it, buf),
-                |buf: &mut _| print_item(self, &self.shared.templates, it, buf, &page),
+                |buf: &mut _| print_item(self, it, buf, &page),
                 &self.shared.style_files,
             )
         } else {
@@ -391,7 +387,6 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             extension_css,
             resource_suffix,
             static_root_path,
-            generate_search_filter,
             unstable_features,
             generate_redirect_map,
             show_type_layout,
@@ -421,12 +416,10 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             default_settings,
             krate: krate.name(tcx).to_string(),
             css_file_extension: extension_css,
-            generate_search_filter,
             scrape_examples_extension: !call_locations.is_empty(),
         };
         let mut issue_tracker_base_url = None;
         let mut include_sources = true;
-        let templates = templates::load()?;
 
         // Crawl the crate attributes looking for attributes which control how we're
         // going to emit HTML
@@ -481,7 +474,6 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             errors: receiver,
             redirections: if generate_redirect_map { Some(Default::default()) } else { None },
             show_type_layout,
-            templates,
             span_correspondance_map: matches,
             cache,
             call_locations,
@@ -577,7 +569,6 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
         };
         let all = self.shared.all.replace(AllTypes::new());
         let v = layout::render(
-            &self.shared.templates,
             &self.shared.layout,
             &page,
             sidebar,
@@ -599,7 +590,6 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             .map(StylePath::basename)
             .collect::<Result<_, Error>>()?;
         let v = layout::render(
-            &self.shared.templates,
             &self.shared.layout,
             &page,
             sidebar,
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index d63df4e4130..dda74904931 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -31,7 +31,6 @@ mod tests;
 mod context;
 mod print_item;
 mod span_map;
-mod templates;
 mod write_shared;
 
 crate use self::context::*;
diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index 4f7bb39213b..11426cb6571 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/src/librustdoc/html/render/print_item.rs
@@ -32,7 +32,7 @@ use crate::html::highlight;
 use crate::html::layout::Page;
 use crate::html::markdown::{HeadingOffset, MarkdownSummaryLine};
 
-use serde::Serialize;
+use askama::Template;
 
 const ITEM_TABLE_OPEN: &str = "<div class=\"item-table\">";
 const ITEM_TABLE_CLOSE: &str = "</div>";
@@ -40,13 +40,13 @@ const ITEM_TABLE_ROW_OPEN: &str = "<div class=\"item-row\">";
 const ITEM_TABLE_ROW_CLOSE: &str = "</div>";
 
 // A component in a `use` path, like `string` in std::string::ToString
-#[derive(Serialize)]
 struct PathComponent<'a> {
     path: String,
     name: &'a str,
 }
 
-#[derive(Serialize)]
+#[derive(Template)]
+#[template(path = "print_item.html")]
 struct ItemVars<'a> {
     page: &'a Page<'a>,
     static_root_path: &'a str,
@@ -58,13 +58,7 @@ struct ItemVars<'a> {
     src_href: Option<&'a str>,
 }
 
-pub(super) fn print_item(
-    cx: &Context<'_>,
-    templates: &tera::Tera,
-    item: &clean::Item,
-    buf: &mut Buffer,
-    page: &Page<'_>,
-) {
+pub(super) fn print_item(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer, page: &Page<'_>) {
     debug_assert!(!item.is_stripped());
     let typ = match *item.kind {
         clean::ModuleItem(_) => {
@@ -143,8 +137,7 @@ pub(super) fn print_item(
         src_href: src_href.as_deref(),
     };
 
-    let teractx = tera::Context::from_serialize(item_vars).unwrap();
-    let heading = templates.render("print_item.html", &teractx).unwrap();
+    let heading = item_vars.render().unwrap();
     buf.write_str(&heading);
 
     match *item.kind {
diff --git a/src/librustdoc/html/render/templates.rs b/src/librustdoc/html/render/templates.rs
deleted file mode 100644
index d1f18239447..00000000000
--- a/src/librustdoc/html/render/templates.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-use std::error::Error as StdError;
-
-use crate::error::Error;
-
-pub(crate) fn load() -> Result<tera::Tera, Error> {
-    let mut templates = tera::Tera::default();
-
-    macro_rules! include_template {
-        ($file:literal, $fullpath:literal) => {
-            templates.add_raw_template($file, include_str!($fullpath)).map_err(|e| Error {
-                file: $file.into(),
-                error: format!("{}: {}", e, e.source().map(|e| e.to_string()).unwrap_or_default()),
-            })?
-        };
-    }
-
-    include_template!("page.html", "../templates/page.html");
-    include_template!("print_item.html", "../templates/print_item.html");
-    Ok(templates)
-}
diff --git a/src/librustdoc/html/render/write_shared.rs b/src/librustdoc/html/render/write_shared.rs
index 563f4ae7385..2e763dbd8fe 100644
--- a/src/librustdoc/html/render/write_shared.rs
+++ b/src/librustdoc/html/render/write_shared.rs
@@ -494,14 +494,7 @@ pub(super) fn write_shared(
                     })
                     .collect::<String>()
             );
-            let v = layout::render(
-                &cx.shared.templates,
-                &cx.shared.layout,
-                &page,
-                "",
-                content,
-                &cx.shared.style_files,
-            );
+            let v = layout::render(&cx.shared.layout, &page, "", content, &cx.shared.style_files);
             cx.shared.fs.write(dst, v)?;
         }
     }