Auto merge of #89695 - jsha:more-templates, r=GuillaumeGomez

Move top part of print_item to Tera templates

Part of #84419.

This moves the first line of each item page (E.g. `Struct foo::Bar .... 1.0.0 [-][src]` into a Tera template.

I also moved template initialization into its own module and added a small macro to reduce duplication and opportunity for errors.

6 files changed, 113 insertions, 55 deletions

diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index b99d2fe5aa0..011d3cfcf72 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -1,6 +1,5 @@
 use std::cell::RefCell;
 use std::collections::BTreeMap;
-use std::error::Error as StdError;
 use std::io;
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
@@ -16,6 +15,7 @@ use rustc_span::symbol::sym;
 
 use super::cache::{build_index, ExternalLocation};
 use super::print_item::{full_path, item_path, print_item};
+use super::templates;
 use super::write_shared::write_shared;
 use super::{
     collect_spans_and_sources, print_sidebar, settings, AllTypes, LinkFromSrc, NameDoc, StylePath,
@@ -33,7 +33,6 @@ use crate::formats::FormatRenderer;
 use crate::html::escape::Escape;
 use crate::html::format::Buffer;
 use crate::html::markdown::{self, plain_text_summary, ErrorCodes, IdMap};
-use crate::html::static_files::PAGE;
 use crate::html::{layout, sources};
 
 /// Major driving force in all rustdoc rendering. This contains information
@@ -225,7 +224,7 @@ impl<'tcx> Context<'tcx> {
                 &self.shared.layout,
                 &page,
                 |buf: &mut _| print_sidebar(self, it, buf),
-                |buf: &mut _| print_item(self, it, buf, &page),
+                |buf: &mut _| print_item(self, &self.shared.templates, it, buf, &page),
                 &self.shared.style_files,
             )
         } else {
@@ -416,12 +415,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
         };
         let mut issue_tracker_base_url = None;
         let mut include_sources = true;
-
-        let mut templates = tera::Tera::default();
-        templates.add_raw_template("page.html", PAGE).map_err(|e| Error {
-            file: "page.html".into(),
-            error: format!("{}: {}", e, e.source().map(|e| e.to_string()).unwrap_or_default()),
-        })?;
+        let templates = templates::load()?;
 
         // Crawl the crate attributes looking for attributes which control how we're
         // going to emit HTML
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 4f189159747..dc5aec3b084 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -31,6 +31,7 @@ mod tests;
 mod context;
 mod print_item;
 mod span_map;
+mod templates;
 mod write_shared;
 
 crate use context::*;
diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index cab3fca708b..4cfc57ac995 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/src/librustdoc/html/render/print_item.rs
@@ -32,16 +32,41 @@ use crate::html::highlight;
 use crate::html::layout::Page;
 use crate::html::markdown::{HeadingOffset, MarkdownSummaryLine};
 
+use serde::Serialize;
+
 const ITEM_TABLE_OPEN: &'static str = "<div class=\"item-table\">";
 const ITEM_TABLE_CLOSE: &'static str = "</div>";
 const ITEM_TABLE_ROW_OPEN: &'static str = "<div class=\"item-row\">";
 const ITEM_TABLE_ROW_CLOSE: &'static str = "</div>";
 
-pub(super) fn print_item(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer, page: &Page<'_>) {
+// A component in a `use` path, like `string` in std::string::ToString
+#[derive(Serialize)]
+struct PathComponent<'a> {
+    path: String,
+    name: &'a str,
+}
+
+#[derive(Serialize)]
+struct ItemVars<'a> {
+    page: &'a Page<'a>,
+    static_root_path: &'a str,
+    typ: &'a str,
+    name: &'a str,
+    item_type: &'a str,
+    path_components: Vec<PathComponent<'a>>,
+    stability_since_raw: &'a str,
+    src_href: Option<&'a str>,
+}
+
+pub(super) fn print_item(
+    cx: &Context<'_>,
+    templates: &tera::Tera,
+    item: &clean::Item,
+    buf: &mut Buffer,
+    page: &Page<'_>,
+) {
     debug_assert!(!item.is_stripped());
-    // Write the breadcrumb trail header for the top
-    buf.write_str("<h1 class=\"fqn\"><span class=\"in-band\">");
-    let name = match *item.kind {
+    let typ = match *item.kind {
         clean::ModuleItem(_) => {
             if item.is_crate() {
                 "Crate "
@@ -73,48 +98,15 @@ pub(super) fn print_item(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer,
             unreachable!();
         }
     };
-    buf.write_str(name);
-    if !item.is_primitive() && !item.is_keyword() {
-        let cur = &cx.current;
-        let amt = if item.is_mod() { cur.len() - 1 } else { cur.len() };
-        for (i, component) in cur.iter().enumerate().take(amt) {
-            write!(
-                buf,
-                "<a href=\"{}index.html\">{}</a>::<wbr>",
-                "../".repeat(cur.len() - i - 1),
-                component
-            );
-        }
-    }
-    write!(buf, "<a class=\"{}\" href=\"#\">{}</a>", item.type_(), item.name.as_ref().unwrap());
-    write!(
-        buf,
-        "<button id=\"copy-path\" onclick=\"copy_path(this)\" title=\"Copy item path to clipboard\">\
-            <img src=\"{static_root_path}clipboard{suffix}.svg\" \
-                width=\"19\" height=\"18\" \
-                alt=\"Copy item path\">\
-         </button>",
-        static_root_path = page.get_static_root_path(),
-        suffix = page.resource_suffix,
-    );
-
-    buf.write_str("</span>"); // in-band
-    buf.write_str("<span class=\"out-of-band\">");
+    let mut stability_since_raw = Buffer::new();
     render_stability_since_raw(
-        buf,
+        &mut stability_since_raw,
         item.stable_since(cx.tcx()).as_deref(),
         item.const_stability(cx.tcx()),
         None,
         None,
     );
-    buf.write_str(
-        "<span id=\"render-detail\">\
-                <a id=\"toggle-all-docs\" href=\"javascript:void(0)\" \
-                    title=\"collapse all docs\">\
-                    [<span class=\"inner\">&#x2212;</span>]\
-                </a>\
-            </span>",
-    );
+    let stability_since_raw: String = stability_since_raw.into_inner();
 
     // Write `src` tag
     //
@@ -122,11 +114,38 @@ pub(super) fn print_item(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer,
     // [src] link in the downstream documentation will actually come back to
     // this page, and this link will be auto-clicked. The `id` attribute is
     // used to find the link to auto-click.
-    if cx.include_sources && !item.is_primitive() {
-        write_srclink(cx, item, buf);
-    }
+    let src_href =
+        if cx.include_sources && !item.is_primitive() { cx.src_href(item) } else { None };
+
+    let path_components = if item.is_primitive() || item.is_keyword() {
+        vec![]
+    } else {
+        let cur = &cx.current;
+        let amt = if item.is_mod() { cur.len() - 1 } else { cur.len() };
+        cur.iter()
+            .enumerate()
+            .take(amt)
+            .map(|(i, component)| PathComponent {
+                path: "../".repeat(cur.len() - i - 1),
+                name: component,
+            })
+            .collect()
+    };
+
+    let item_vars = ItemVars {
+        page: page,
+        static_root_path: page.get_static_root_path(),
+        typ: typ,
+        name: &item.name.as_ref().unwrap().as_str(),
+        item_type: &item.type_().to_string(),
+        path_components: path_components,
+        stability_since_raw: &stability_since_raw,
+        src_href: src_href.as_deref(),
+    };
 
-    buf.write_str("</span></h1>"); // out-of-band
+    let teractx = tera::Context::from_serialize(item_vars).unwrap();
+    let heading = templates.render("print_item.html", &teractx).unwrap();
+    buf.write_str(&heading);
 
     match *item.kind {
         clean::ModuleItem(ref m) => item_module(buf, cx, item, &m.items),
diff --git a/src/librustdoc/html/render/templates.rs b/src/librustdoc/html/render/templates.rs
new file mode 100644
index 00000000000..d1f18239447
--- /dev/null
+++ b/src/librustdoc/html/render/templates.rs
@@ -0,0 +1,20 @@
+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/static_files.rs b/src/librustdoc/html/static_files.rs
index 6f3d08ea655..ccc25e6cc49 100644
--- a/src/librustdoc/html/static_files.rs
+++ b/src/librustdoc/html/static_files.rs
@@ -70,8 +70,6 @@ crate static RUST_FAVICON_SVG: &[u8] = include_bytes!("static/images/favicon.svg
 crate static RUST_FAVICON_PNG_16: &[u8] = include_bytes!("static/images/favicon-16x16.png");
 crate static RUST_FAVICON_PNG_32: &[u8] = include_bytes!("static/images/favicon-32x32.png");
 
-crate static PAGE: &str = include_str!("templates/page.html");
-
 /// The built-in themes given to every documentation site.
 crate mod themes {
     /// The "light" theme, selected by default when no setting is available. Used as the basis for
diff --git a/src/librustdoc/html/templates/print_item.html b/src/librustdoc/html/templates/print_item.html
new file mode 100644
index 00000000000..5a468f3cc1e
--- /dev/null
+++ b/src/librustdoc/html/templates/print_item.html
@@ -0,0 +1,26 @@
+<h1 class="fqn"> {#- -#}
+    <span class="in-band"> {#- -#}
+        {{-typ-}}
+        {#- The breadcrumbs of the item path, like std::string -#}
+        {%- for component in path_components -%}
+        <a href="{{component.path | safe}}index.html">{{component.name}}</a>::<wbr>
+        {%- endfor -%}
+        <a class="{{item_type}}" href="#">{{name}}</a> {#- -#}
+        <button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"> {#- -#}
+            <img src="{{static_root_path | safe}}clipboard{{page.resource_suffix}}.svg" {# -#}
+                width="19" height="18" {# -#}
+                alt="Copy item path"> {#- -#}
+        </button> {#- -#}
+    </span> {#- -#}
+    <span class="out-of-band"> {#- -#}
+        {{- stability_since_raw | safe -}}
+        <span id="render-detail"> {#- -#}
+            <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs"> {#- -#}
+                [<span class="inner">&#x2212;</span>] {#- -#}
+            </a> {#- -#}
+        </span> {#- -#}
+        {%- if src_href -%}
+        <a class="srclink" href="{{src_href | safe}}" title="goto source code">[src]</a>
+        {%- endif -%}
+    </span> {#- -#}
+</h1> {#- -#}