Move HTML ID list creation into a macro

Author: GuillaumeGomez

src/librustdoc/html/markdown.rs

@@ -1436,50 +1436,63 @@ pub struct IdMap {
 }
 
 fn init_id_map() -> FxHashMap<String, usize> {
-    let mut map = FxHashMap::default();
-    // This is the list of IDs used in Javascript.
-    map.insert("help".to_owned(), 1);
-    // This is the list of IDs used in HTML generated in Rust (including the ones
-    // used in tera template files).
-    map.insert("mainThemeStyle".to_owned(), 1);
-    map.insert("themeStyle".to_owned(), 1);
-    map.insert("theme-picker".to_owned(), 1);
-    map.insert("theme-choices".to_owned(), 1);
-    map.insert("settings-menu".to_owned(), 1);
-    map.insert("help-button".to_owned(), 1);
-    map.insert("main".to_owned(), 1);
-    map.insert("search".to_owned(), 1);
-    map.insert("crate-search".to_owned(), 1);
-    map.insert("render-detail".to_owned(), 1);
-    map.insert("toggle-all-docs".to_owned(), 1);
-    map.insert("all-types".to_owned(), 1);
-    map.insert("default-settings".to_owned(), 1);
-    map.insert("rustdoc-vars".to_owned(), 1);
-    map.insert("sidebar-vars".to_owned(), 1);
-    map.insert("copy-path".to_owned(), 1);
-    map.insert("TOC".to_owned(), 1);
-    // This is the list of IDs used by rustdoc sections (but still generated by
-    // rustdoc).
-    map.insert("fields".to_owned(), 1);
-    map.insert("variants".to_owned(), 1);
-    map.insert("implementors-list".to_owned(), 1);
-    map.insert("synthetic-implementors-list".to_owned(), 1);
-    map.insert("foreign-impls".to_owned(), 1);
-    map.insert("implementations".to_owned(), 1);
-    map.insert("trait-implementations".to_owned(), 1);
-    map.insert("synthetic-implementations".to_owned(), 1);
-    map.insert("blanket-implementations".to_owned(), 1);
-    map.insert("associated-types".to_owned(), 1);
-    map.insert("associated-const".to_owned(), 1);
-    map.insert("required-methods".to_owned(), 1);
-    map.insert("provided-methods".to_owned(), 1);
-    map.insert("implementors".to_owned(), 1);
-    map.insert("synthetic-implementors".to_owned(), 1);
-    map.insert("trait-implementations-list".to_owned(), 1);
-    map.insert("synthetic-implementations-list".to_owned(), 1);
-    map.insert("blanket-implementations-list".to_owned(), 1);
-    map.insert("deref-methods".to_owned(), 1);
-    map
+    // We declare the ID map this way to make it simpler for the HTML IDs tidy check to extract
+    // the IDs.
+    macro_rules! html_id_map {
+        ($($id:literal,)+) => {{
+            let mut map = FxHashMap::default();
+
+            $(
+                map.insert($id.to_owned(), 1);
+            )+
+            map
+        }}
+    }
+
+    html_id_map!(
+        // This is the list of IDs used in Javascript.
+        "help",
+        // This is the list of IDs used in HTML generated in Rust (including the ones
+        // used in tera template files).
+        "mainThemeStyle",
+        "themeStyle",
+        "theme-picker",
+        "theme-choices",
+        "settings-menu",
+        "help-button",
+        "main",
+        "search",
+        "crate-search",
+        "render-detail",
+        "toggle-all-docs",
+        "all-types",
+        "default-settings",
+        "rustdoc-vars",
+        "sidebar-vars",
+        "copy-path",
+        "TOC",
+        // This is the list of IDs used by rustdoc sections (but still generated by
+        // rustdoc).
+        "fields",
+        "variants",
+        "implementors-list",
+        "synthetic-implementors-list",
+        "foreign-impls",
+        "implementations",
+        "trait-implementations",
+        "synthetic-implementations",
+        "blanket-implementations",
+        "associated-types",
+        "associated-const",
+        "required-methods",
+        "provided-methods",
+        "implementors",
+        "synthetic-implementors",
+        "trait-implementations-list",
+        "synthetic-implementations-list",
+        "blanket-implementations-list",
+        "deref-methods",
+    )
 }
 
 impl IdMap {