Warn on deprecated Python-specific index types (#11412)

14 files changed, 91 insertions, 71 deletions

diff --git a/CHANGES b/CHANGES
index 631ec3b7b..cbc9d348c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -14,6 +14,11 @@ Incompatible changes
 Deprecated
 ----------
 
+* #11412: Emit warnings on using a deprecated Python-specific index entry type
+  (namely, ``module``, ``keyword``, ``operator``, ``object``, ``exception``,
+  ``statement``, and ``builtin``) in the :rst:dir:`index` directive, and
+  set the removal version to Sphinx 9. Patch by Adam Turner.
+
 Features added
 --------------
 
diff --git a/doc/usage/configuration.rst b/doc/usage/configuration.rst
index 11cd2be31..23e9ba7ab 100644
--- a/doc/usage/configuration.rst
+++ b/doc/usage/configuration.rst
@@ -337,6 +337,7 @@ General configuration
    * ``epub.unknown_project_files``
    * ``epub.duplicated_toc_entry``
    * ``i18n.inconsistent_references``
+   * ``index``
    * ``image.not_readable``
    * ``ref.term``
    * ``ref.ref``
@@ -388,6 +389,10 @@ General configuration
 
       Added ``i18n.inconsistent_references``
 
+    .. versionadded:: 7.1
+
+        Added ``index`` warning type.
+
 .. confval:: needs_sphinx
 
    If set to a ``major.minor`` version string like ``'1.1'``, Sphinx will
diff --git a/doc/usage/restructuredtext/directives.rst b/doc/usage/restructuredtext/directives.rst
index c9152d1b1..7082af046 100644
--- a/doc/usage/restructuredtext/directives.rst
+++ b/doc/usage/restructuredtext/directives.rst
@@ -896,9 +896,10 @@ mainly contained in information units, such as the language reference.
 
       .. index::
          single: execution; context
-         module: __main__
-         module: sys
+         pair: module; __main__
+         pair: module; sys
          triple: module; search; path
+         seealso: scope
 
       The execution context
       ---------------------
@@ -916,25 +917,63 @@ mainly contained in information units, such as the language reference.
    The possible entry types are:
 
    single
-      Creates a single index entry.  Can be made a subentry by separating the
-      subentry text with a semicolon (this notation is also used below to
-      describe what entries are created).
+      Creates a single index entry.
+      Can be made a sub-entry by separating the sub-entry text with a semicolon
+      (this notation is also used below to describe what entries are created).
+      Examples:
+
+      .. code:: reStructuredText
+
+         .. index:: single: execution
+                    single: execution; context
+
+      - ``single: execution`` creates an index entry labelled ``execution``.
+      - ``single: execution; context`` creates an sub-entry of ``execution``
+        labelled ``context``.
    pair
-      ``pair: loop; statement`` is a shortcut that creates two index entries,
-      namely ``loop; statement`` and ``statement; loop``.
+      A shortcut to create two index entries.
+      The pair of values must be separated by a semicolon.
+      Example:
+
+      .. code:: reStructuredText
+
+         .. index:: pair: loop; statement
+
+      This would create two index entries; ``loop; statement`` and ``statement; loop``.
    triple
-      Likewise, ``triple: module; search; path`` is a shortcut that creates
-      three index entries, which are ``module; search path``, ``search; path,
-      module`` and ``path; module search``.
+      A shortcut to create three index entries.
+      All three values must be separated by a semicolon.
+      Example:
+
+      .. code:: reStructuredText
+
+         .. index:: triple: module; search; path
+
+      This would create three index entries; ``module; search path``,
+      ``search; path, module``, and ``path; module search``.
    see
-      ``see: entry; other`` creates an index entry that refers from ``entry`` to
-      ``other``.
+      A shortcut to create an index entry that refers to another entry.
+      Example:
+
+      .. code:: reStructuredText
+
+         .. index:: see: entry; other
+
+      This would create an index entry referring from ``entry`` to ``other``
+      (i.e. 'entry': See 'other').
    seealso
-      Like ``see``, but inserts "see also" instead of "see".
+      Like ``see``, but inserts 'see also' instead of 'see'.
    module, keyword, operator, object, exception, statement, builtin
-      These all create two index entries.  For example, ``module: hashlib``
-      creates the entries ``module; hashlib`` and ``hashlib; module``.  (These
-      are Python-specific and therefore deprecated.)
+      These **deprecated** shortcuts all create two index entries.
+      For example, ``module: hashlib`` creates the entries ``module; hashlib``
+      and ``hashlib; module``.
+
+      .. deprecated:: 1.0
+         These Python-specific entry types are deprecated.
+
+      .. versionchanged:: 7.1
+         Removal version set to Sphinx 9.0.
+         Using these entry types will now emit warnings with the ``index`` category.
 
    You can mark up "main" index entries by prefixing them with an exclamation
    mark.  The references to "main" entries are emphasized in the generated
diff --git a/sphinx/builders/gettext.py b/sphinx/builders/gettext.py
index 4d460109b..697b75e40 100644
--- a/sphinx/builders/gettext.py
+++ b/sphinx/builders/gettext.py
@@ -16,7 +16,6 @@ from docutils.nodes import Element
 from sphinx import addnodes, package_dir
 from sphinx.application import Sphinx
 from sphinx.builders import Builder
-from sphinx.domains.python import pairindextypes
 from sphinx.errors import ThemeError
 from sphinx.locale import __
 from sphinx.util import logging, split_index_msg
@@ -159,10 +158,6 @@ class I18nBuilder(Builder):
             for node, entries in traverse_translatable_index(doctree):
                 for typ, msg, _tid, _main, _key in entries:
                     for m in split_index_msg(typ, msg):
-                        if typ == 'pair' and m in pairindextypes.values():
-                            # avoid built-in translated message was incorporated
-                            # in 'sphinx.util.nodes.process_index_entry'
-                            continue
                         catalog.add(m, node)
 
 
diff --git a/sphinx/domains/python.py b/sphinx/domains/python.py
index c461cc311..eef78aa80 100644
--- a/sphinx/domains/python.py
+++ b/sphinx/domains/python.py
@@ -50,13 +50,13 @@ py_sig_re = re.compile(
 
 
 pairindextypes = {
-    'module':    _('module'),
-    'keyword':   _('keyword'),
-    'operator':  _('operator'),
-    'object':    _('object'),
-    'exception': _('exception'),
-    'statement': _('statement'),
-    'builtin':   _('built-in function'),
+    'module': 'module',
+    'keyword': 'keyword',
+    'operator': 'operator',
+    'object': 'object',
+    'exception': 'exception',
+    'statement': 'statement',
+    'builtin': 'built-in function',
 }
 
 
@@ -729,7 +729,7 @@ class PyFunction(PyObject):
                 text = _('%s() (in module %s)') % (name, modname)
                 self.indexnode['entries'].append(('single', text, node_id, '', None))
             else:
-                text = f'{pairindextypes["builtin"]}; {name}()'
+                text = f'built-in function; {name}()'
                 self.indexnode['entries'].append(('pair', text, node_id, '', None))
 
     def get_index_text(self, modname: str, name_cls: tuple[str, str]) -> str | None:
@@ -1058,7 +1058,7 @@ class PyModule(SphinxDirective):
             # the platform and synopsis aren't printed; in fact, they are only
             # used in the modindex currently
             ret.append(target)
-            indextext = f'{pairindextypes["module"]}; {modname}'
+            indextext = f'module; {modname}'
             inode = addnodes.index(entries=[('pair', indextext, node_id, '', None)])
             ret.append(inode)
         ret.extend(content_node.children)
diff --git a/sphinx/locale/__init__.py b/sphinx/locale/__init__.py
index c92640576..8ab90d191 100644
--- a/sphinx/locale/__init__.py
+++ b/sphinx/locale/__init__.py
@@ -223,9 +223,3 @@ admonitionlabels = {
     'tip':       _('Tip'),
     'warning':   _('Warning'),
 }
-
-# Moved to sphinx.directives.other (will be overridden later)
-versionlabels: dict[str, str] = {}
-
-# Moved to sphinx.domains.python (will be overridden later)
-pairindextypes: dict[str, str] = {}
diff --git a/sphinx/util/nodes.py b/sphinx/util/nodes.py
index 1b43bd72e..3dfdd4f26 100644
--- a/sphinx/util/nodes.py
+++ b/sphinx/util/nodes.py
@@ -365,19 +365,23 @@ def process_index_entry(entry: str, targetid: str,
     if entry.startswith('!'):
         main = 'main'
         entry = entry[1:].lstrip()
-    for type in pairindextypes:
-        if entry.startswith(type + ':'):
-            value = entry[len(type) + 1:].strip()
-            value = pairindextypes[type] + '; ' + value
+    for index_type in pairindextypes:
+        if entry.startswith(f'{index_type}:'):
+            value = entry[len(index_type) + 1:].strip()
+            value = f'{pairindextypes[index_type]}; {value}'
+            # xref RemovedInSphinx90Warning
+            logger.warning(__('%r is deprecated for index entries (from entry %r). '
+                              "Use 'pair: %s' instead."),
+                           index_type, entry, value, type='index')
             indexentries.append(('pair', value, targetid, main, None))
             break
     else:
-        for type in indextypes:
-            if entry.startswith(type + ':'):
-                value = entry[len(type) + 1:].strip()
-                if type == 'double':
-                    type = 'pair'
-                indexentries.append((type, value, targetid, main, None))
+        for index_type in indextypes:
+            if entry.startswith(f'{index_type}:'):
+                value = entry[len(index_type) + 1:].strip()
+                if index_type == 'double':
+                    index_type = 'pair'
+                indexentries.append((index_type, value, targetid, main, None))
                 break
         # shorthand notation for single entries
         else:
diff --git a/tests/roots/test-intl/index_entries.txt b/tests/roots/test-intl/index_entries.txt
index c914a4b43..e9300d0ef 100644
--- a/tests/roots/test-intl/index_entries.txt
+++ b/tests/roots/test-intl/index_entries.txt
@@ -20,12 +20,5 @@ various index entries
    triple: First; Second; Third
    see: Entry; Mailing List
    seealso: See; Newsletter
-   module: Module
-   keyword: Keyword
-   operator: Operator
-   object: Object
-   exception: Exception
-   statement: Statement
-   builtin: Builtin
 
 That's all.
diff --git a/tests/roots/test-root/markup.txt b/tests/roots/test-root/markup.txt
index 41a2fa583..b59a652ee 100644
--- a/tests/roots/test-root/markup.txt
+++ b/tests/roots/test-root/markup.txt
@@ -373,7 +373,6 @@ Index markup
    pair: entry; pair
    double: entry; double
    triple: index; entry; triple
-   keyword: with
    see: from; to
    seealso: fromalso; toalso
 
diff --git a/tests/roots/test-warnings/index.rst b/tests/roots/test-warnings/index.rst
index 4110e93d0..8c4f6bb8a 100644
--- a/tests/roots/test-warnings/index.rst
+++ b/tests/roots/test-warnings/index.rst
@@ -27,7 +27,7 @@ Don't download :download:`this <nonexisting.png>`.
 .. index::
    single:
    pair:
-   keyword:
+   seealso:
 
 .. Invalid code-block
 .. code-block:: c
diff --git a/tests/test_build_gettext.py b/tests/test_build_gettext.py
index ebd46275a..dee9757b0 100644
--- a/tests/test_build_gettext.py
+++ b/tests/test_build_gettext.py
@@ -117,13 +117,6 @@ def test_gettext_index_entries(app):
         "Third",
         "Entry",
         "See",
-        "Module",
-        "Keyword",
-        "Operator",
-        "Object",
-        "Exception",
-        "Statement",
-        "Builtin",
     ]
     for expect in expected_msgids:
         assert expect in msgids
diff --git a/tests/test_environment_indexentries.py b/tests/test_environment_indexentries.py
index 2fb7faee0..4cfdc2823 100644
--- a/tests/test_environment_indexentries.py
+++ b/tests/test_environment_indexentries.py
@@ -1,4 +1,4 @@
-"""Test the sphinx.environment.managers.indexentries."""
+"""Test the sphinx.environment.adapters.indexentries."""
 
 import pytest
 
diff --git a/tests/test_environment_toctree.py b/tests/test_environment_toctree.py
index 3488fe138..9b0047bed 100644
--- a/tests/test_environment_toctree.py
+++ b/tests/test_environment_toctree.py
@@ -1,4 +1,4 @@
-"""Test the sphinx.environment.managers.toctree."""
+"""Test the sphinx.environment.adapters.toctree."""
 
 import pytest
 from docutils import nodes
diff --git a/tests/test_intl.py b/tests/test_intl.py
index feabe0e62..54fa113c1 100644
--- a/tests/test_intl.py
+++ b/tests/test_intl.py
@@ -727,13 +727,6 @@ def test_html_index_entries(app):
         wrap('a', 'THIRD, FIRST'),
         wrap_nest('li', 'ul', 'ENTRY'),
         wrap_nest('li', 'ul', 'SEE'),
-        wrap('a', 'MODULE'),
-        wrap('a', 'KEYWORD'),
-        wrap('a', 'OPERATOR'),
-        wrap('a', 'OBJECT'),
-        wrap('a', 'EXCEPTION'),
-        wrap('a', 'STATEMENT'),
-        wrap('a', 'BUILTIN'),
     ]
     for expr in expected_exprs:
         assert_re_search(expr, result, re.M)