Add EnvironmentManager.get_updated_docs() to weaken the coupling env modules

sphinx/environment/__init__.py

@@ -647,8 +647,9 @@ class BuildEnvironment(object):
 
     def check_dependents(self, already):
         # type: (Set[unicode]) -> Iterator[unicode]
-        to_rewrite = (self.toctree.assign_section_numbers() +  # type: ignore
+        to_rewrite = []
-                      self.toctree.assign_figure_numbers())  # type: ignore
+        for manager in itervalues(self.managers):
+            to_rewrite.extend(manager.get_updated_docs())
         for docname in set(to_rewrite):
             if docname not in already:
                 yield docname

sphinx/environment/managers/__init__.py

@@ -48,3 +48,7 @@ class EnvironmentManager(object):
     def process_doc(self, docname, doctree):
         # type: (unicode, nodes.Node) -> None
         raise NotImplementedError
+
+    def get_updated_docs(self):
+        # type: () -> List[unicode]
+        raise NotImplementedError

sphinx/environment/managers/indexentries.py

@@ -65,6 +65,10 @@ class IndexEntries(EnvironmentManager):
                     else:
                         entries.append(entry + (None,))
 
+    def get_updated_docs(self):
+        # type: () -> List[unicode]
+        return []
+
     def create_index(self, builder, group_entries=True,
                      _fixre=re.compile(r'(.*) ([(][^()]*[)])')):
         # type: (Builder, bool, Pattern) -> List[Tuple[unicode, List[Tuple[unicode, List[unicode]]]]]  # NOQA

sphinx/environment/managers/toctree.py

@@ -144,6 +144,10 @@ class Toctree(EnvironmentManager):
             self.tocs[docname] = nodes.bullet_list('')
         self.toc_num_entries[docname] = numentries[0]
 
+    def get_updated_docs(self):
+        # type: () -> List[unicode]
+        return self.assign_section_numbers() + self.assign_figure_numbers()
+
     def note_toctree(self, docname, toctreenode):
         # type: (unicode, addnodes.toctree) -> None
         """Note a TOC tree directive in a document and gather information about