[Docs] Update website theme for newer Sphinx (#22872)

Fixes #15365

Replaces the custom theme with the last version of sphinx_rtd_theme,
and then adds the changes found by diffing the emscripten custom theme
with sphinx_rtd_theme version 0.1.6.

Author: lorsanta

.flake8

@@ -7,6 +7,7 @@ exclude =
  ./tools/scons/, # third-party code
  ./test/third_party/, # third-party code
  ./site/source/conf.py,
+ ./site/source/_themes/,
  ./system/lib/, # system libraries
  ./cache/, # download/built content
  .git

.mypy.ini

@@ -6,6 +6,7 @@ exclude = (?x)(
   third_party |
   conf\.py |
   emrun\.py |
+  site/source/_themes/ |
   tools/scons/site_scons/site_tools/emscripten/__init__\.py |
   site/source/get_wiki\.py |
   test/parse_benchmark_output\.py

requirements-dev.txt

@@ -17,20 +17,8 @@ lxml==4.9.2
 
 # This version is mentioned in `site/source/docs/site/about.rst`.
 # Please keep them in sync.
-sphinx==2.4.4
-# See https://github.com/emscripten-core/emscripten/issues/21590
-sphinxcontrib-applehelp<=1.0.4
-sphinxcontrib-devhelp<=1.0.2
-sphinxcontrib-htmlhelp<=2.0.0
-sphinxcontrib-serializinghtml<=1.1.5
-sphinxcontrib-qthelp<=1.0.3
-alabaster<=0.7.12
-pygments==2.17.2
-# See https://github.com/readthedocs/readthedocs.org/issues/9038
-jinja2<3.1
-
-# Pin docutils because newer versions are not compatible with sphinx 2.4.4
-docutils==0.17.1
+sphinx==7.1.2
+sphinxcontrib-jquery==4.0
 
 # Needed by test/test_sockets.py
 websockify==0.10.0

site/Makefile

@@ -4,13 +4,13 @@
 # You can set these variables from the command line.
 SPHINXOPTS    = -W
 SPHINXBUILD   = sphinx-build
-SPHINXVERSION = 2.4.4
+SPHINXVERSION = 7.1.2
 PAPER         =
 BUILDDIR      = build
 
 # User-friendly check for sphinx-build
 ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
-$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx version 2.4.4 installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
+$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx version 7.1.2 installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
 endif
 
 ifneq ($(shell $(SPHINXBUILD) --version), $(SPHINXBUILD) $(SPHINXVERSION))

site/source/_themes/emscripten_sphinx_rtd_theme/__init__.py

@@ -3,20 +3,109 @@
 # University of Illinois/NCSA Open Source License.  Both these licenses can be
 # found in the LICENSE file.
 
-"""Sphinx ReadTheDocs theme.
+"""
+Sphinx Read the Docs theme.
 
 From https://github.com/ryan-roemer/sphinx-bootstrap-theme.
-
 """
+
 import os
+from os import path
+from sys import version_info as python_version
 
-VERSION = (0, 1, 6)
+from sphinx import version_info as sphinx_version
+from sphinx.locale import _
+from sphinx.util.logging import getLogger
 
-__version__ = ".".join(str(v) for v in VERSION)
+
+__version__ = '3.0.1'
 __version_full__ = __version__
 
+logger = getLogger(__name__)
+
 
 def get_html_theme_path():
     """Return list of HTML theme paths."""
-    cur_dir = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
+    logger.warning(
+        _('Calling get_html_theme_path is deprecated. If you are calling it to define html_theme_path, you are safe to remove that code.')
+    )
+
+    cur_dir = path.abspath(path.dirname(path.dirname(__file__)))
     return cur_dir
+
+
+def config_initiated(app, config):
+    theme_options = config.html_theme_options or {}
+    if theme_options.get('canonical_url'):
+        logger.warning(
+            _('The canonical_url option is deprecated, use the html_baseurl option from Sphinx instead.')
+        )
+
+    if theme_options.get("analytics_id"):
+        logger.warning(
+            _('The analytics_id option is deprecated, use the sphinxcontrib-googleanalytics extension instead.')
+        )
+
+    if theme_options.get("analytics_anonymize_ip"):
+        logger.warning(
+            _('The analytics_anonymize_ip option is deprecated, use the sphinxcontrib-googleanalytics extension instead.')
+        )
+
+    if "extra_css_files" in config.html_context:
+        logger.warning(
+            _('The extra_css_file option is deprecated, use the html_css_files option from Sphinx instead.')
+        )
+
+
+def extend_html_context(app, pagename, templatename, context, doctree):
+     # Add ``sphinx_version_info`` tuple for use in Jinja templates
+     context['sphinx_version_info'] = sphinx_version
+
+     # Inject all the Read the Docs environment variables in the context:
+     # https://docs.readthedocs.io/en/stable/reference/environment-variables.html
+     context['READTHEDOCS'] = os.environ.get("READTHEDOCS", False) == "True"
+     if context['READTHEDOCS']:
+         for key, value in os.environ.items():
+             if key.startswith("READTHEDOCS_"):
+                 context[key] = value
+
+
+
+# See http://www.sphinx-doc.org/en/stable/theming.html#distribute-your-theme-as-a-python-package
+def setup(app):
+    if python_version[0] < 3:
+        logger.error("Python 2 is not supported with sphinx_rtd_theme, update to Python 3.")
+
+    app.require_sphinx('6.0')
+    if app.config.html4_writer:
+        logger.error("'html4_writer' is not supported with sphinx_rtd_theme.")
+
+    # Since Sphinx 6, jquery isn't bundled anymore and we need to ensure that
+    # the sphinxcontrib-jquery extension is enabled.
+    # See: https://dev.readthedocs.io/en/latest/design/sphinx-jquery.html
+    if sphinx_version >= (6, 0, 0):
+        # Documentation of Sphinx guarantees that an extension is added and
+        # enabled at most once.
+        # See: https://www.sphinx-doc.org/en/master/extdev/appapi.html#sphinx.application.Sphinx.setup_extension
+        app.setup_extension("sphinxcontrib.jquery")
+        # However, we need to call the extension's callback since setup_extension doesn't do it
+        # See: https://github.com/sphinx-contrib/jquery/issues/23
+        from sphinxcontrib.jquery import add_js_files as jquery_add_js_files
+        jquery_add_js_files(app, app.config)
+
+    # Register the theme that can be referenced without adding a theme path
+    app.add_html_theme('sphinx_rtd_theme', path.abspath(path.dirname(__file__)))
+
+    # Add Sphinx message catalog for newer versions of Sphinx
+    # See http://www.sphinx-doc.org/en/master/extdev/appapi.html#sphinx.application.Sphinx.add_message_catalog
+    rtd_locale_path = path.join(path.abspath(path.dirname(__file__)), 'locale')
+    app.add_message_catalog('sphinx', rtd_locale_path)
+    app.connect('config-inited', config_initiated)
+
+    # sphinx emits the permalink icon for headers, so choose one more in keeping with our theme
+    app.config.html_permalinks_icon = "\uf0c1"
+
+    # Extend the default context when rendering the templates.
+    app.connect("html-page-context", extend_html_context)
+
+    return {'parallel_read_safe': True, 'parallel_write_safe': True}