Decl styling, update writers

Add test objects so all builders gets exposed to the new nodes.
Make the fallback node post-transform change desc_inline as well.
Make the html4, latex, and text writers handle desc_inline.

sphinx/transforms/post_transforms/__init__.py

@@ -206,7 +206,7 @@ def run(self, **kwargs: Any) -> None:
 
 
 class SigElementFallbackTransform(SphinxPostTransform):
-    """Fallback desc_sig_element nodes to inline if translator does not supported them."""
+    """Fallback various desc_* nodes to inline if translator does not supported them."""
     default_priority = 200
 
     def run(self, **kwargs: Any) -> None:
@@ -218,14 +218,15 @@ def has_visitor(translator: Type[nodes.NodeVisitor], node: Type[Element]) -> boo
             # subclass of SphinxTranslator supports desc_sig_element nodes automatically.
             return
 
-        if all(has_visitor(translator, node) for node in addnodes.SIG_ELEMENTS):
-            # the translator supports all desc_sig_element nodes
-            return
-        else:
-            self.fallback()
+        # for the leaf elements (desc_sig_element), the translator should support _all_
+        if not all(has_visitor(translator, node) for node in addnodes.SIG_ELEMENTS):
+            self.fallback(addnodes.desc_sig_element)
+
+        if not has_visitor(translator, addnodes.desc_inline):
+            self.fallback(addnodes.desc_inline)
 
-    def fallback(self) -> None:
-        for node in self.document.traverse(addnodes.desc_sig_element):
+    def fallback(self, nodeType: Any) -> None:
+        for node in self.document.traverse(nodeType):
             newnode = nodes.inline()
             newnode.update_all_atts(node)
             newnode.extend(node)

sphinx/writers/html.py

@@ -146,6 +146,12 @@ def visit_desc_content(self, node: Element) -> None:
     def depart_desc_content(self, node: Element) -> None:
         self.body.append('</dd>')
 
+    def visit_desc_inline(self, node: Element) -> None:
+        self.body.append(self.starttag(node, 'span', ''))
+
+    def depart_desc_inline(self, node: Element) -> None:
+        self.body.append('</span>')
+
     # Nodes for high-level structure in signatures
     ##############################################
 

sphinx/writers/latex.py

@@ -698,6 +698,13 @@ def visit_subtitle(self, node: Element) -> None:
     def depart_subtitle(self, node: Element) -> None:
         self.body.append(self.context.pop())
 
+    #############################################################
+    # Domain-specific object descriptions
+    #############################################################
+
+    # Top-level nodes for descriptions
+    ##################################
+
     def visit_desc(self, node: Element) -> None:
         if self.config.latex_show_urls == 'footnote':
             self.body.append(BLANKLINE)
@@ -750,6 +757,31 @@ def visit_desc_signature_line(self, node: Element) -> None:
     def depart_desc_signature_line(self, node: Element) -> None:
         self._depart_signature_line(node)
 
+    def visit_desc_content(self, node: Element) -> None:
+        if node.children and not isinstance(node.children[0], nodes.paragraph):
+            # avoid empty desc environment which causes a formatting bug
+            self.body.append('~')
+
+    def depart_desc_content(self, node: Element) -> None:
+        pass
+
+    def visit_desc_inline(self, node: Element) -> None:
+        self.body.append(r'\sphinxcode{\sphinxupquote{')
+
+    def depart_desc_inline(self, node: Element) -> None:
+        self.body.append('}}')
+
+    # Nodes for high-level structure in signatures
+    ##############################################
+
+    def visit_desc_name(self, node: Element) -> None:
+        self.body.append(r'\sphinxbfcode{\sphinxupquote{')
+        self.literal_whitespace += 1
+
+    def depart_desc_name(self, node: Element) -> None:
+        self.body.append('}}')
+        self.literal_whitespace -= 1
+
     def visit_desc_addname(self, node: Element) -> None:
         self.body.append(r'\sphinxcode{\sphinxupquote{')
         self.literal_whitespace += 1
@@ -770,14 +802,6 @@ def visit_desc_returns(self, node: Element) -> None:
     def depart_desc_returns(self, node: Element) -> None:
         self.body.append(r'}')
 
-    def visit_desc_name(self, node: Element) -> None:
-        self.body.append(r'\sphinxbfcode{\sphinxupquote{')
-        self.literal_whitespace += 1
-
-    def depart_desc_name(self, node: Element) -> None:
-        self.body.append('}}')
-        self.literal_whitespace -= 1
-
     def visit_desc_parameterlist(self, node: Element) -> None:
         # close name, open parameterlist
         self.body.append('}{')
@@ -811,13 +835,7 @@ def visit_desc_annotation(self, node: Element) -> None:
     def depart_desc_annotation(self, node: Element) -> None:
         self.body.append('}}')
 
-    def visit_desc_content(self, node: Element) -> None:
-        if node.children and not isinstance(node.children[0], nodes.paragraph):
-            # avoid empty desc environment which causes a formatting bug
-            self.body.append('~')
-
-    def depart_desc_content(self, node: Element) -> None:
-        pass
+    ##############################################
 
     def visit_seealso(self, node: Element) -> None:
         self.body.append(BLANKLINE)

sphinx/writers/manpage.py

@@ -120,6 +120,13 @@ def visit_start_of_file(self, node: Element) -> None:
     def depart_start_of_file(self, node: Element) -> None:
         pass
 
+    #############################################################
+    # Domain-specific object descriptions
+    #############################################################
+
+    # Top-level nodes for descriptions
+    ##################################
+
     def visit_desc(self, node: Element) -> None:
         self.visit_definition_list(node)
 
@@ -139,6 +146,21 @@ def visit_desc_signature_line(self, node: Element) -> None:
     def depart_desc_signature_line(self, node: Element) -> None:
         self.body.append(' ')
 
+    def visit_desc_content(self, node: Element) -> None:
+        self.visit_definition(node)
+
+    def depart_desc_content(self, node: Element) -> None:
+        self.depart_definition(node)
+
+    # Nodes for high-level structure in signatures
+    ##############################################
+
+    def visit_desc_name(self, node: Element) -> None:
+        pass
+
+    def depart_desc_name(self, node: Element) -> None:
+        pass
+
     def visit_desc_addname(self, node: Element) -> None:
         pass
 
@@ -157,12 +179,6 @@ def visit_desc_returns(self, node: Element) -> None:
     def depart_desc_returns(self, node: Element) -> None:
         pass
 
-    def visit_desc_name(self, node: Element) -> None:
-        pass
-
-    def depart_desc_name(self, node: Element) -> None:
-        pass
-
     def visit_desc_parameterlist(self, node: Element) -> None:
         self.body.append('(')
         self.first_param = 1
@@ -191,11 +207,7 @@ def visit_desc_annotation(self, node: Element) -> None:
     def depart_desc_annotation(self, node: Element) -> None:
         pass
 
-    def visit_desc_content(self, node: Element) -> None:
-        self.visit_definition(node)
-
-    def depart_desc_content(self, node: Element) -> None:
-        self.depart_definition(node)
+    ##############################################
 
     def visit_versionmodified(self, node: Element) -> None:
         self.visit_paragraph(node)

sphinx/writers/text.py

@@ -536,6 +536,13 @@ def visit_attribution(self, node: Element) -> None:
     def depart_attribution(self, node: Element) -> None:
         pass
 
+    #############################################################
+    # Domain-specific object descriptions
+    #############################################################
+
+    # Top-level nodes
+    #################
+
     def visit_desc(self, node: Element) -> None:
         pass
 
@@ -555,6 +562,22 @@ def visit_desc_signature_line(self, node: Element) -> None:
     def depart_desc_signature_line(self, node: Element) -> None:
         self.add_text('\n')
 
+    def visit_desc_content(self, node: Element) -> None:
+        self.new_state()
+        self.add_text(self.nl)
+
+    def depart_desc_content(self, node: Element) -> None:
+        self.end_state()
+
+    def visit_desc_inline(self, node: Element) -> None:
+        pass
+
+    def depart_desc_inline(self, node: Element) -> None:
+        pass
+
+    # Nodes for high-level structure in signatures
+    ##############################################
+
     def visit_desc_name(self, node: Element) -> None:
         pass
 
@@ -606,12 +629,7 @@ def visit_desc_annotation(self, node: Element) -> None:
     def depart_desc_annotation(self, node: Element) -> None:
         pass
 
-    def visit_desc_content(self, node: Element) -> None:
-        self.new_state()
-        self.add_text(self.nl)
-
-    def depart_desc_content(self, node: Element) -> None:
-        self.end_state()
+    ##############################################
 
     def visit_figure(self, node: Element) -> None:
         self.new_state()

tests/roots/test-root/objects.txt

@@ -213,3 +213,9 @@ CPP domain
 
    .. cpp:function:: T& operator[]( unsigned j )
                      const T& operator[]( unsigned j ) const
+
+.. cpp:function:: template<typename T1, typename T2> \
+                     requires A<T1, T2> \
+                  void f()
+
+- :cpp:expr:`a + b`