Simplify distribution of version-switcher.js

Author: GuillaumeGomez

src/bootstrap/doc.rs

@@ -11,7 +11,6 @@ use std::ffi::OsStr;
 use std::fs;
 use std::io;
 use std::path::{Path, PathBuf};
-use std::str::FromStr;
 
 use crate::builder::{Builder, Compiler, Kind, RunConfig, ShouldRun, Step};
 use crate::cache::{Interned, INTERNER};
@@ -401,18 +400,6 @@ impl Step for Standalone {
     }
 }
 
-fn get_doc_max_version(builder: &Builder<'_>) -> String {
-    let reduce_by = match builder.config.channel.as_str() {
-        "dev" => 3,
-        "nightly" => 2,
-        "beta" => 1,
-        _ => 0,
-    };
-    let parts = builder.version.split(".").collect::<Vec<_>>();
-    let medium = t!(u32::from_str(parts[1]));
-    format!("{}.{}.{}", parts[0], medium - reduce_by, parts[2..].join("."))
-}
-
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct Std {
     pub stage: u32,
@@ -443,12 +430,9 @@ impl Step for Std {
         t!(fs::create_dir_all(&out));
         t!(fs::copy(builder.src.join("src/doc/rust.css"), out.join("rust.css")));
 
-        let version = get_doc_max_version(&builder);
-
-        let content = t!(fs::read_to_string(builder.src.join("src/doc/version-switcher.js")));
-        t!(fs::write(
-            out.join("version-switcher.js"),
-            content.replace("/* VERSION TO BE REPLACED */", &version),
+        t!(fs::copy(
+            builder.src.join("src/doc/version-switcher.js"),
+            out.join("version-switcher.js")
         ));
 
         let index_page = builder.src.join("src/doc/index.md").into_os_string();

src/doc/version-switcher.js

@@ -1,4 +1,21 @@
-const CURRENT_VERSION = "/* VERSION TO BE REPLACED */";
+(function() {
+
+let CURRENT_VERSION = -1;
+
+function get_current_version() {
+    if (CURRENT_VERSION !== -1) {
+        return CURRENT_VERSION;
+    }
+    const now = Date.now();
+    // Month is 0-indexed.
+    // First release of Rust, 15 may 2015.
+    const first_release = new Date(2015, 4, 15);
+    const diff_time = Math.abs(now - first_release);
+    const nb_days = Math.ceil(diff_time / (1000 * 60 * 60 * 24));
+    const nb_weeks = nb_days / 7;
+    CURRENT_VERSION = Math.floor(nb_weeks / 6);
+    return CURRENT_VERSION;
+}
 
 function checkIfIsOldVersion() {
     if (["http:", "https:"].indexOf(window.location.protocol) === -1) {
@@ -159,12 +176,9 @@ function showSwitcher(isOldVersion) {
     version_picker.appendChild(createOption("beta", current_doc_version === "beta"));
     version_picker.appendChild(createOption("nightly", current_doc_version === "nightly"));
 
-    const version_parts = CURRENT_VERSION.split(".");
-    for (let major = parseInt(version_parts[0]); major >= 1; --major) {
-        for (let medium = parseInt(version_parts[1]); medium >= 0; --medium) {
-            const version = `${major}.${medium}.0`;
-            version_picker.appendChild(createOption(version, version === current_doc_version));
-        }
+    for (let medium = get_current_version(); medium >= 0; --medium) {
+        const version = `1.${medium}.0`;
+        version_picker.appendChild(createOption(version, version === current_doc_version));
     }
 
     version_picker.style.color = "#000";
@@ -208,3 +222,5 @@ function showSwitcher(isOldVersion) {
 }
 
 showSwitcher(checkIfIsOldVersion());
+
+}());