[v3] doc: fix the switchers menu

diff --git a/doc/.gitignore b/doc/.gitignore
index 69fa449dd96..dee9494dcaf 100644
--- a/doc/.gitignore
+++ b/doc/.gitignore
@@ -1 +1,2 @@ 
 _build/
+sphinx-static/switchers.js
diff --git a/doc/Makefile b/doc/Makefile
index 996f01b7d5c..5e1632314c5 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -27,7 +27,7 @@  publish: Makefile html singlehtml
 	sed -i -e 's@index.html#@singleindex.html#@g' $(BUILDDIR)/$(DESTDIR)/singleindex.html
 
 clean:
-	@rm -rf $(BUILDDIR)
+	@rm -rf $(BUILDDIR) sphinx-static/switchers.js
 
 # Catch-all target: route all unknown targets to Sphinx using the new
 # "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
diff --git a/doc/conf.py b/doc/conf.py
index bce386624e2..9318358731c 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -6,20 +6,16 @@ 
 
 # -- Path setup --------------------------------------------------------------
 
-# If extensions (or modules to document with autodoc) are in another directory,
-# add these directories to sys.path here. If the directory is relative to the
-# documentation root, use os.path.abspath to make it absolute, like shown here.
-#
-# import os
-# import sys
-# sys.path.insert(0, os.path.abspath('.'))
-
-import sys
 import datetime
+import os
+import sys
 
 from pathlib import Path
 
-current_version = "dev"
+sys.path.insert(0, os.path.abspath('.'))
+import setversions
+
+current_version = setversions.get_current_version()
 
 # String used in sidebar
 version = 'Version: ' + current_version
@@ -28,6 +24,10 @@  if current_version == 'dev':
 # Version seen in documentation_options.js and hence in js switchers code
 release = current_version
 
+setversions.write_switchers_js("sphinx-static/switchers.js.in",
+                               "sphinx-static/switchers.js",
+                               current_version)
+
 # -- Project information -----------------------------------------------------
 
 project = 'Bitbake'
diff --git a/doc/setversions.py b/doc/setversions.py
new file mode 100755
index 00000000000..9e4138025ac
--- /dev/null
+++ b/doc/setversions.py
@@ -0,0 +1,132 @@ 
+#!/usr/bin/env python3
+#
+# This file defines is used in doc/conf.py to setup the version information for
+# the documentation:
+# - get_current_version() used in doc/conf.py computes the current version by
+#   trying to guess the approximate versions we're at using git tags and
+#   branches from the repository.
+# - write_switchers_js() write the switchers.js file used for switching between
+#   versions of the documentation.
+#
+# Copyright (c) 2026 Antonin Godard <antonin.godard@bootlin.com>
+#
+# SPDX-License-Identifier: MIT
+#
+
+import itertools
+import re
+import subprocess
+import sys
+
+DEVBRANCH = "2.18"
+LTSSERIES = ["2.8", "2.0"]
+ACTIVERELEASES = ["2.16"] + LTSSERIES
+
+YOCTO_MAPPING = {
+    "2.18": "wrynose",
+    "2.16": "whinlatter",
+    "2.12": "walnascar",
+    "2.10": "styhead",
+    "2.8": "scarthgap",
+    "2.6": "nanbield",
+    "2.4": "mickledore",
+    "2.2": "langdale",
+    "2.0": "kirkstone",
+    "1.52": "honister",
+    "1.50": "hardknott",
+    "1.48": "gatesgarth",
+    "1.46": "dunfell",
+}
+
+BB_RELEASE_TAG_RE = re.compile(r"^[0-9]+\.[0-9]+\.[0-9]+$")
+
+def get_current_version():
+    ourversion = None
+
+    # Test that we are building from a Git repository
+    try:
+        subprocess.run(["git", "rev-parse", "--is-inside-work-tree"],
+                       stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True)
+    except subprocess.CalledProcessError:
+        sys.exit("Building bitbake's documentation must be done from its Git repository.\n"
+                 "Clone the repository with the following command:\n"
+                 "git clone https://git.openembedded.org/bitbake ")
+
+    # Test tags exist and inform the user to fetch if not
+    try:
+        subprocess.run(["git", "show", f"{LTSSERIES[0]}.0"],
+                       stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True)
+    except subprocess.CalledProcessError:
+        sys.exit("Please run 'git fetch --tags' before building the documentation")
+
+
+    # Try and figure out what we are
+    tags = subprocess.run(["git", "tag", "--points-at", "HEAD"],
+                          stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                          universal_newlines=True).stdout
+    for t in tags.split():
+        if re.match(BB_RELEASE_TAG_RE, t):
+            ourversion = t
+            break
+
+    if ourversion:
+        # We're a tagged release
+        components = ourversion.split(".")
+    else:
+        # We're floating on a branch
+        branch = subprocess.run(["git", "branch", "--show-current"],
+                                stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                                universal_newlines=True).stdout.strip()
+
+        if branch == "" or branch not in list(YOCTO_MAPPING.keys()) + ["master", "master-next"]:
+            # We're not on a known release branch so we have to guess. Compare the
+            # numbers of commits from each release branch and assume the smallest
+            # number of commits is the one we're based off
+            possible_branch = None
+            branch_count = 0
+            for b in itertools.chain(YOCTO_MAPPING.keys(), ["master"]):
+                result = subprocess.run(["git", "log", "--format=oneline", "HEAD..origin/" + b],
+                                        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                                        universal_newlines=True)
+                if result.returncode == 0:
+                    count = result.stdout.count('\n')
+                    if not possible_branch or count < branch_count:
+                        print("Branch %s has count %s" % (b, count))
+                        possible_branch = b
+                        branch_count = count
+            if possible_branch:
+                branch = possible_branch
+            else:
+                branch = "master"
+            print("Nearest release branch estimated to be %s" % branch)
+
+        if branch == "master":
+            ourversion = "dev"
+        elif branch == "master-next":
+            ourversion = "next"
+        else:
+            ourversion = branch
+            head_commit = subprocess.run(["git", "rev-parse", "--short", "HEAD"],
+                                         stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                                         universal_newlines=True).stdout.strip()
+            branch_commit = subprocess.run(["git", "rev-parse", "--short", branch],
+                                            stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                                            universal_newlines=True).stdout.strip()
+            if head_commit != branch_commit:
+                ourversion += f" ({head_commit})"
+
+    print("Version calculated to be %s" % ourversion)
+    return ourversion
+
+def write_switchers_js(js_in, js_out, current_version):
+    with open(js_in, "r") as r, open(js_out, "w") as w:
+        lines = r.readlines()
+        for line in lines:
+            if "VERSIONS_PLACEHOLDER" in line:
+                if current_version != "dev":
+                    w.write(f"    'dev': 'Unstable (dev)',\n")
+                for series in ACTIVERELEASES:
+                    w.write(f"    '{series}': '{series} ({YOCTO_MAPPING[series]})',\n")
+            else:
+                w.write(line)
+        print("switchers.js generated from switchers.js.in")
diff --git a/doc/sphinx-static/switchers.js b/doc/sphinx-static/switchers.js
deleted file mode 100644
index 32113cfa960..00000000000
--- a/doc/sphinx-static/switchers.js
+++ /dev/null
@@ -1,233 +0,0 @@ 
-(function() {
-  'use strict';
-
-  var all_versions = {
-    'dev': 'dev (3.2)',
-    '3.1.2': '3.1.2',
-    '3.0.3': '3.0.3',
-    '2.7.4': '2.7.4',
-  };
-
-  var all_doctypes = {
-      'single': 'Individual Webpages',
-      'mega': "All-in-one 'Mega' Manual",
-  };
-
-  // Simple version comparision
-  // Return 1 if a > b
-  // Return -1 if a < b
-  // Return 0 if a == b
-  function ver_compare(a, b) {
-    if (a == "dev") {
-       return 1;
-    }
-
-    if (a === b) {
-       return 0;
-    }
-
-    var a_components = a.split(".");
-    var b_components = b.split(".");
-
-    var len = Math.min(a_components.length, b_components.length);
-
-    // loop while the components are equal
-    for (var i = 0; i < len; i++) {
-        // A bigger than B
-        if (parseInt(a_components[i]) > parseInt(b_components[i])) {
-            return 1;
-        }
-
-        // B bigger than A
-        if (parseInt(a_components[i]) < parseInt(b_components[i])) {
-            return -1;
-        }
-    }
-
-    // If one's a prefix of the other, the longer one is greater.
-    if (a_components.length > b_components.length) {
-        return 1;
-    }
-
-    if (a_components.length < b_components.length) {
-        return -1;
-    }
-
-    // Otherwise they are the same.
-    return 0;
-  }
-
-  function build_version_select(current_series, current_version) {
-    var buf = ['<select>'];
-
-    $.each(all_versions, function(version, title) {
-      var series = version.substr(0, 3);
-      if (series == current_series) {
-        if (version == current_version)
-            buf.push('<option value="' + version + '" selected="selected">' + title + '</option>');
-        else
-            buf.push('<option value="' + version + '">' + title + '</option>');
-
-        if (version != current_version)
-            buf.push('<option value="' + current_version + '" selected="selected">' + current_version + '</option>');
-      } else {
-        buf.push('<option value="' + version + '">' + title + '</option>');
-      }
-    });
-
-    buf.push('</select>');
-    return buf.join('');
-  }
-
-  function build_doctype_select(current_doctype) {
-    var buf = ['<select>'];
-
-    $.each(all_doctypes, function(doctype, title) {
-      if (doctype == current_doctype)
-        buf.push('<option value="' + doctype + '" selected="selected">' +
-                 all_doctypes[current_doctype] + '</option>');
-      else
-        buf.push('<option value="' + doctype + '">' + title + '</option>');
-    });
-    if (!(current_doctype in all_doctypes)) {
-        // In case we're browsing a doctype that is not yet in all_doctypes.
-        buf.push('<option value="' + current_doctype + '" selected="selected">' +
-                 current_doctype + '</option>');
-        all_doctypes[current_doctype] = current_doctype;
-    }
-    buf.push('</select>');
-    return buf.join('');
-  }
-
-  function navigate_to_first_existing(urls) {
-    // Navigate to the first existing URL in urls.
-    var url = urls.shift();
-
-    // Web browsers won't redirect file:// urls to file urls using ajax but
-    // its useful for local testing
-    if (url.startsWith("file://")) {
-      window.location.href = url;
-      return;
-    }
-
-    if (urls.length == 0) {
-      window.location.href = url;
-      return;
-    }
-    $.ajax({
-      url: url,
-      success: function() {
-        window.location.href = url;
-      },
-      error: function() {
-        navigate_to_first_existing(urls);
-      }
-    });
-  }
-
-  function get_docroot_url() {
-    var url = window.location.href;
-    var root = DOCUMENTATION_OPTIONS.URL_ROOT;
-
-    var urlarray = url.split('/');
-    // Trim off anything after '/'
-    urlarray.pop();
-    var depth = (root.match(/\.\.\//g) || []).length;
-    for (var i = 0; i < depth; i++) {
-      urlarray.pop();
-    }
-
-    return urlarray.join('/') + '/';
-  }
-
-  function on_version_switch() {
-    var selected_version = $(this).children('option:selected').attr('value');
-    var url = window.location.href;
-    var current_version = DOCUMENTATION_OPTIONS.VERSION;
-    var docroot = get_docroot_url()
-
-    var new_versionpath = selected_version + '/';
-    if (selected_version == "dev")
-        new_versionpath = '';
-
-    // dev versions have no version prefix
-    if (current_version == "dev") {
-        var new_url = docroot + new_versionpath + url.replace(docroot, "");
-        var fallback_url = docroot + new_versionpath;
-    } else {
-        var new_url = url.replace('/' + current_version + '/', '/' + new_versionpath);
-        var fallback_url = new_url.replace(url.replace(docroot, ""), "");
-    }
-
-    console.log(get_docroot_url())
-    console.log(url + " to url " + new_url);
-    console.log(url + " to fallback " + fallback_url);
-
-    if (new_url != url) {
-      navigate_to_first_existing([
-        new_url,
-        fallback_url,
-        'https://www.yoctoproject.org/docs/',
-      ]);
-    }
-  }
-
-  function on_doctype_switch() {
-    var selected_doctype = $(this).children('option:selected').attr('value');
-    var url = window.location.href;
-    if (selected_doctype == 'mega') {
-      var docroot = get_docroot_url()
-      var current_version = DOCUMENTATION_OPTIONS.VERSION;
-      // Assume manuals before 3.2 are using old docbook mega-manual
-      if (ver_compare(current_version, "3.2") < 0) {
-        var new_url = docroot + "mega-manual/mega-manual.html";
-      } else {
-        var new_url = docroot + "singleindex.html";
-      }
-    } else {
-      var new_url = url.replace("singleindex.html", "index.html")
-    }
-
-    if (new_url != url) {
-      navigate_to_first_existing([
-        new_url,
-        'https://www.yoctoproject.org/docs/',
-      ]);
-    }
-  }
-
-  // Returns the current doctype based upon the url
-  function doctype_segment_from_url(url) {
-    if (url.includes("singleindex") || url.includes("mega-manual"))
-      return "mega";
-    return "single";
-  }
-
-  $(document).ready(function() {
-    var release = DOCUMENTATION_OPTIONS.VERSION;
-    var current_doctype = doctype_segment_from_url(window.location.href);
-    var current_series = release.substr(0, 3);
-    var version_select = build_version_select(current_series, release);
-
-    $('.version_switcher_placeholder').html(version_select);
-    $('.version_switcher_placeholder select').bind('change', on_version_switch);
-
-    var doctype_select = build_doctype_select(current_doctype);
-
-    $('.doctype_switcher_placeholder').html(doctype_select);
-    $('.doctype_switcher_placeholder select').bind('change', on_doctype_switch);
-
-    if (ver_compare(release, "3.1") < 0) {
-      $('#outdated-warning').html('Version ' + release + ' of the project is now considered obsolete, please select and use a more recent version');
-      $('#outdated-warning').css('padding', '.5em');
-    } else if (release != "dev") {
-      $.each(all_versions, function(version, title) {
-        var series = version.substr(0, 3);
-        if (series == current_series && version != release) {
-          $('#outdated-warning').html('This document is for outdated version ' + release + ', you should select the latest release version in this series, ' + version + '.');
-          $('#outdated-warning').css('padding', '.5em');
-        }
-      });
-    }
-  });
-})();
diff --git a/doc/sphinx-static/switchers.js.in b/doc/sphinx-static/switchers.js.in
new file mode 100644
index 00000000000..0b209e959da
--- /dev/null
+++ b/doc/sphinx-static/switchers.js.in
@@ -0,0 +1,249 @@ 
+// SPDX-License-Identifier: MIT
+(function () {
+  "use strict";
+
+  var all_versions = {
+    VERSIONS_PLACEHOLDER,
+  };
+
+  var all_doctypes = {
+    single: "Individual Webpages",
+    mega: "All-in-one 'Mega' Manual",
+  };
+
+  // Simple version comparision
+  // Return 1 if a > b
+  // Return -1 if a < b
+  // Return 0 if a == b
+  function ver_compare(a, b) {
+    if (a == "dev") {
+      return 1;
+    }
+
+    if (a === b) {
+      return 0;
+    }
+
+    var a_components = a.split(".");
+    var b_components = b.split(".");
+
+    var len = Math.min(a_components.length, b_components.length);
+
+    // loop while the components are equal
+    for (var i = 0; i < len; i++) {
+      // A bigger than B
+      if (parseInt(a_components[i]) > parseInt(b_components[i])) {
+        return 1;
+      }
+
+      // B bigger than A
+      if (parseInt(a_components[i]) < parseInt(b_components[i])) {
+        return -1;
+      }
+    }
+
+    // If one's a prefix of the other, the longer one is greater.
+    if (a_components.length > b_components.length) {
+      return 1;
+    }
+
+    if (a_components.length < b_components.length) {
+      return -1;
+    }
+
+    // Otherwise they are the same.
+    return 0;
+  }
+
+  function build_version_select(current_version) {
+    var buf = ["<select>"];
+
+    $.each(all_versions, function (version, title) {
+      if (current_version != version) {
+        buf.push(
+          '<option value="' +
+          version +
+          '" selected="selected">' +
+          title +
+          "</option>",
+        );
+      }
+    });
+
+    var current_title = current_version;
+    if (current_version in all_versions) {
+      current_title = all_versions[current_version];
+    }
+    buf.push(
+      '<option value="' +
+        current_version +
+        '" selected="selected">' +
+        current_title +
+        "</option>",
+    );
+
+    buf.push("</select>");
+    return buf.join("");
+  }
+
+  function build_doctype_select(current_doctype) {
+    var buf = ["<select>"];
+
+    $.each(all_doctypes, function (doctype, title) {
+      if (doctype == current_doctype)
+        buf.push(
+          '<option value="' +
+            doctype +
+            '" selected="selected">' +
+            all_doctypes[current_doctype] +
+            "</option>",
+        );
+      else buf.push('<option value="' + doctype + '">' + title + "</option>");
+    });
+    if (!(current_doctype in all_doctypes)) {
+      // In case we're browsing a doctype that is not yet in all_doctypes.
+      buf.push(
+        '<option value="' +
+          current_doctype +
+          '" selected="selected">' +
+          current_doctype +
+          "</option>",
+      );
+      all_doctypes[current_doctype] = current_doctype;
+    }
+    buf.push("</select>");
+    return buf.join("");
+  }
+
+  function navigate_to_first_existing(urls) {
+    // Navigate to the first existing URL in urls.
+    var url = urls.shift();
+
+    // Web browsers won't redirect file:// urls to file urls using ajax but
+    // its useful for local testing
+    if (url.startsWith("file://")) {
+      window.location.href = url;
+      return;
+    }
+
+    if (urls.length == 0) {
+      window.location.href = url;
+      return;
+    }
+    $.ajax({
+      url: url,
+      success: function () {
+        window.location.href = url;
+      },
+      error: function () {
+        navigate_to_first_existing(urls);
+      },
+    });
+  }
+
+  function get_docroot_url() {
+    var url = window.location.href;
+    // Try to get the variable from documentation_options.js
+    var root = DOCUMENTATION_OPTIONS.URL_ROOT;
+    if (root == null) {
+      // In recent versions of Sphinx, URL_ROOT was removed from
+      // documentation_options.js, so get it like searchtools.js does.
+      root = document.documentElement.dataset.content_root;
+    }
+
+    var urlarray = url.split("/");
+    // Trim off anything after '/'
+    urlarray.pop();
+    var depth = (root.match(/\.\.\//g) || []).length;
+    for (var i = 0; i < depth; i++) {
+      urlarray.pop();
+    }
+
+    return urlarray.join("/") + "/";
+  }
+
+  function on_version_switch() {
+    var selected_version = $(this).children("option:selected").attr("value");
+    var url = window.location.href;
+    var current_version = DOCUMENTATION_OPTIONS.VERSION;
+    var docroot = get_docroot_url();
+
+    var new_versionpath = selected_version + "/";
+
+    // latest tag is also the default page (without version information)
+    if (docroot.endsWith("dev/")) {
+      var new_url = url.replace("/dev/", "/" + new_versionpath);
+      var fallback_url = new_url.replace(url.replace(docroot, ""), "");
+    } else if (docroot.endsWith(current_version + "/") == false) {
+      var new_url = docroot + new_versionpath + url.replace(docroot, "");
+      var fallback_url = docroot + new_versionpath;
+    } else {
+      var new_url = url.replace(
+        "/" + current_version + "/",
+        "/" + new_versionpath,
+      );
+      var fallback_url = new_url.replace(url.replace(docroot, ""), "");
+    }
+
+    console.log(url + " to url " + new_url);
+    console.log(url + " to fallback " + fallback_url);
+
+    if (new_url != url) {
+      navigate_to_first_existing([
+        new_url,
+        fallback_url,
+        "https://www.yoctoproject.org/bitbake/",
+      ]);
+    }
+  }
+
+  function on_doctype_switch() {
+    var selected_doctype = $(this).children("option:selected").attr("value");
+    var url = window.location.href;
+    if (selected_doctype == "mega") {
+      var docroot = get_docroot_url();
+      var current_version = DOCUMENTATION_OPTIONS.VERSION;
+      var new_url = docroot + "singleindex.html";
+    } else {
+      var new_url = url.replace("singleindex.html", "index.html");
+    }
+
+    if (new_url != url) {
+      navigate_to_first_existing([
+        new_url,
+        "https://www.yoctoproject.org/docs/",
+      ]);
+    }
+  }
+
+  // Returns the current doctype based upon the url
+  function doctype_segment_from_url(url) {
+    if (url.includes("singleindex") || url.includes("mega-manual"))
+      return "mega";
+    return "single";
+  }
+
+  $(document).ready(function () {
+    var release = DOCUMENTATION_OPTIONS.VERSION;
+    var current_doctype = doctype_segment_from_url(window.location.href);
+    var current_series = release.substr(0, 3);
+    var version_select = build_version_select(release);
+
+    $(".version_switcher_placeholder").html(version_select);
+    $(".version_switcher_placeholder select").bind("change", on_version_switch);
+
+    var doctype_select = build_doctype_select(current_doctype);
+
+    $(".doctype_switcher_placeholder").html(doctype_select);
+    $(".doctype_switcher_placeholder select").bind("change", on_doctype_switch);
+
+    // if release = "X.Y (<abbrev hash>)", remove the "(<abbrev hash>)" so that only X.Y is compared
+    release = release.split(" ")[0];
+    if (!(["dev", "next"].includes(release)) && !(release in all_versions)) {
+      $("#outdated-warning").html(
+        "Version " + release + " of the project is now considered obsolete, please select and use a more recent version",
+      );
+      $("#outdated-warning").css("padding", ".5em");
+    }
+  });
+})();