Allow extensions to define the keys returned by linkcode ext

doc/extdev/appapi.rst

@@ -79,6 +79,8 @@ package.
 
 .. automethod:: Sphinx.add_autodoc_attrgetter
 
+.. automethod:: Sphinx.add_linkcode_domain
+
 .. automethod:: Sphinx.add_search_language
 
 .. automethod:: Sphinx.add_source_suffix

sphinx/application.py

@@ -1178,6 +1178,15 @@ def add_autodoc_attrgetter(self, typ: type, getter: Callable[[Any, str, Any], An
         logger.debug('[app] adding autodoc attrgetter: %r', (typ, getter))
         self.registry.add_autodoc_attrgetter(typ, getter)
 
+    def add_linkcode_domain(self, domain: str, keys: list[str]) -> None:
+        """Register a new list of keys to use for a domain by the
+        :mod:`sphinx.ext.linkcode` extension.
+
+        .. versionadded:: 7.3
+        """
+        from sphinx.ext.linkcode import domain_keys
+        domain_keys[domain] = keys
+
     def add_search_language(self, cls: Any) -> None:
         """Register a new language for the HTML search index.
 

sphinx/ext/linkcode.py

@@ -17,6 +17,14 @@
     from sphinx.application import Sphinx
 
 
+domain_keys = {
+    'py': ['module', 'fullname'],
+    'c': ['names'],
+    'cpp': ['names'],
+    'js': ['object', 'fullname'],
+}
+
+
 class LinkcodeError(SphinxError):
     category = "linkcode error"
 
@@ -30,13 +38,6 @@ def doctree_read(app: Sphinx, doctree: Node) -> None:
         raise LinkcodeError(msg)
     assert resolve_target is not None  # for mypy
 
-    domain_keys = {
-        'py': ['module', 'fullname'],
-        'c': ['names'],
-        'cpp': ['names'],
-        'js': ['object', 'fullname'],
-    }
-
     for objnode in list(doctree.findall(addnodes.desc)):
         domain = objnode.get('domain')
         uris: set[str] = set()