diff --git a/src/librustdoc/html/layout.rs b/src/librustdoc/html/layout.rs
index 03ad784ef77c..17094aac4bed 100644
--- a/src/librustdoc/html/layout.rs
+++ b/src/librustdoc/html/layout.rs
@@ -54,6 +54,7 @@ struct PageLayout<'a> {
     sidebar: String,
     content: String,
     krate_with_trailing_slash: String,
+    crate rustdoc_version: &'a str,
 }
 
 crate fn render<T: Print, S: Print>(
@@ -71,6 +72,7 @@ crate fn render<T: Print, S: Print>(
         .map(StylePath::basename)
         .collect::<Result<_, Error>>()
         .unwrap_or_default();
+    let rustdoc_version = rustc_interface::util::version_str().unwrap_or("unknown version");
     let content = Buffer::html().to_display(t); // Note: This must happen before making the sidebar.
     let sidebar = Buffer::html().to_display(sidebar);
     let teractx = tera::Context::from_serialize(PageLayout {
@@ -81,6 +83,7 @@ crate fn render<T: Print, S: Print>(
         sidebar,
         content,
         krate_with_trailing_slash,
+        rustdoc_version,
     })
     .unwrap();
     templates.render("page.html", &teractx).unwrap()
diff --git a/src/librustdoc/html/render/write_shared.rs b/src/librustdoc/html/render/write_shared.rs
index 6b0f8dad4c50..cbb575586361 100644
--- a/src/librustdoc/html/render/write_shared.rs
+++ b/src/librustdoc/html/render/write_shared.rs
@@ -265,26 +265,7 @@ pub(super) fn write_shared(
     let mut themes: Vec<&String> = themes.iter().collect();
     themes.sort();
 
-    // FIXME: this should probably not be a toolchain file since it depends on `--theme`.
-    // But it seems a shame to copy it over and over when it's almost always the same.
-    // Maybe we can change the representation to move this out of main.js?
-    write_minify(
-        "main.js",
-        static_files::MAIN_JS
-            .replace(
-                "/* INSERT THEMES HERE */",
-                &format!(" = {}", serde_json::to_string(&themes).unwrap()),
-            )
-            .replace(
-                "/* INSERT RUSTDOC_VERSION HERE */",
-                &format!(
-                    "rustdoc {}",
-                    rustc_interface::util::version_str().unwrap_or("unknown version")
-                ),
-            ),
-        cx,
-        options,
-    )?;
+    write_minify("main.js", static_files::MAIN_JS, cx, options)?;
     write_minify("search.js", static_files::SEARCH_JS, cx, options)?;
     write_minify("settings.js", static_files::SETTINGS_JS, cx, options)?;
 
@@ -292,18 +273,7 @@ pub(super) fn write_shared(
         write_minify("source-script.js", static_files::sidebar::SOURCE_SCRIPT, cx, options)?;
     }
 
-    {
-        write_minify(
-            "storage.js",
-            format!(
-                "var resourcesSuffix = \"{}\";{}",
-                cx.shared.resource_suffix,
-                static_files::STORAGE_JS
-            ),
-            cx,
-            options,
-        )?;
-    }
+    write_minify("storage.js", static_files::STORAGE_JS, cx, options)?;
 
     if cx.shared.layout.scrape_examples_extension {
         cx.write_minify(
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index c9fa72cbaab0..4843aa575b8c 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -37,14 +37,29 @@ if (!DOMTokenList.prototype.remove) {
     };
 }
 
-(function () {
-    var rustdocVars = document.getElementById("rustdoc-vars");
-    if (rustdocVars) {
-        window.rootPath = rustdocVars.attributes["data-root-path"].value;
-        window.currentCrate = rustdocVars.attributes["data-current-crate"].value;
-        window.searchJS = rustdocVars.attributes["data-search-js"].value;
-        window.searchIndexJS = rustdocVars.attributes["data-search-index-js"].value;
+// Get a value from the rustdoc-vars div, which is used to convey data from
+// Rust to the JS. If there is no such element, return null.
+function getVar(name) {
+    var el = document.getElementById("rustdoc-vars");
+    if (el) {
+        return el.attributes["data-" + name].value;
+    } else {
+        return null;
     }
+}
+
+// Given a basename (e.g. "storage") and an extension (e.g. ".js"), return a URL
+// for a resource under the root-path, with the resource-suffix.
+function resourcePath(basename, extension) {
+    return getVar("root-path") + basename + getVar("resource-suffix") + extension;
+}
+
+
+(function () {
+    window.rootPath = getVar("root-path");
+    window.currentCrate = getVar("current-crate");
+    window.searchJS =  resourcePath("search", "js");
+    window.searchIndexJS = resourcePath("search-index", "js");
     var sidebarVars = document.getElementById("sidebar-vars");
     if (sidebarVars) {
         window.sidebarCurrent = {
@@ -115,7 +130,7 @@ function hideThemeButtonState() {
 (function () {
     var themeChoices = getThemesElement();
     var themePicker = getThemePickerElement();
-    var availableThemes/* INSERT THEMES HERE */;
+    var availableThemes = getVar("themes").split(",");
 
     function switchThemeButtonState() {
         if (themeChoices.style.display === "block") {
@@ -980,7 +995,7 @@ function hideThemeButtonState() {
         var rustdoc_version = document.createElement("span");
         rustdoc_version.className = "bottom";
         var rustdoc_version_code = document.createElement("code");
-        rustdoc_version_code.innerText = "/* INSERT RUSTDOC_VERSION HERE */";
+        rustdoc_version_code.innerText = "rustdoc " + getVar("rustdoc-version");
         rustdoc_version.appendChild(rustdoc_version_code);
 
         container.appendChild(rustdoc_version);
diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js
index 78ed17e6899e..606c237aea7d 100644
--- a/src/librustdoc/html/static/js/storage.js
+++ b/src/librustdoc/html/static/js/storage.js
@@ -1,5 +1,3 @@
-// From rust:
-/* global resourcesSuffix */
 var darkThemes = ["dark", "ayu"];
 window.currentTheme = document.getElementById("themeStyle");
 window.mainTheme = document.getElementById("mainThemeStyle");
@@ -107,9 +105,8 @@ function getCurrentValue(name) {
 }
 
 function switchTheme(styleElem, mainStyleElem, newTheme, saveTheme) {
-    var fullBasicCss = "rustdoc" + resourcesSuffix + ".css";
-    var fullNewTheme = newTheme + resourcesSuffix + ".css";
-    var newHref = mainStyleElem.href.replace(fullBasicCss, fullNewTheme);
+    var newHref = mainStyleElem.href.replace(
+        /\/rustdoc([^/]*)\.css/, "/" + newTheme + "$1" + ".css");
 
     // If this new value comes from a system setting or from the previously
     // saved theme, no need to save it.
diff --git a/src/librustdoc/html/templates/page.html b/src/librustdoc/html/templates/page.html
index 863bf53eff3a..44a3518828da 100644
--- a/src/librustdoc/html/templates/page.html
+++ b/src/librustdoc/html/templates/page.html
@@ -14,12 +14,13 @@
           id="mainThemeStyle"> {#- -#}
     {%- for theme in themes -%}
         <link rel="stylesheet" type="text/css" {# -#}
+            href="{{static_root_path | safe}}{{theme}}{{page.resource_suffix}}.css" {#- -#}
         {%- if theme == "light" -%}
             id="themeStyle"
         {%- else -%}
             disabled
         {%- endif -%}
-            href="{{static_root_path | safe}}{{theme}}{{page.resource_suffix}}.css"> {#- -#}
+        >
     {%- endfor -%}
     <script id="default-settings" {# -#}
       {% for k, v in layout.default_settings %}
@@ -122,8 +123,10 @@
     <div id="rustdoc-vars" {# -#}
          data-root-path="{{page.root_path | safe}}" {# -#}
          data-current-crate="{{layout.krate}}" {# -#}
-         data-search-index-js="{{page.root_path | safe}}search-index{{page.resource_suffix}}.js" {# -#}
-         data-search-js="{{static_root_path | safe}}search{{page.resource_suffix}}.js"> {#- -#}
+         data-themes="{{themes | join(sep=",") }}" {# -#}
+         data-resource-suffix="{{page.resource_suffix}}" {# -#}
+         data-rustdoc-version="{{rustdoc_version}}" {# -#}
+    > {#- -#}
     </div>
 </body> {#- -#}
 </html> {#- -#}