Add ReferenceResolver as a post-transform

4 files changed, 110 insertions, 33 deletions

diff --git a/sphinx/application.py b/sphinx/application.py
index 97339c62b..c09b738bf 100644
--- a/sphinx/application.py
+++ b/sphinx/application.py
@@ -105,6 +105,7 @@ builtin_extensions = (
     'sphinx.directives.other',
     'sphinx.directives.patches',
     'sphinx.roles',
+    'sphinx.transforms.post_transforms',
     # collectors should be loaded by specific order
     'sphinx.environment.collectors.dependencies',
     'sphinx.environment.collectors.asset',
diff --git a/sphinx/environment/__init__.py b/sphinx/environment/__init__.py
index c46ec7db2..8b08e4915 100644
--- a/sphinx/environment/__init__.py
+++ b/sphinx/environment/__init__.py
@@ -44,6 +44,7 @@ from sphinx.util.matching import compile_matchers
 from sphinx.util.parallel import ParallelTasks, parallel_available, make_chunks
 from sphinx.util.websupport import is_commentable
 from sphinx.errors import SphinxError, ExtensionError
+from sphinx.transforms import SphinxTransformer
 from sphinx.versioning import add_uids, merge_doctrees
 from sphinx.deprecation import RemovedInSphinx20Warning
 from sphinx.environment.adapters.indexentries import IndexEntries
@@ -920,38 +921,16 @@ class BuildEnvironment(object):
 
     def resolve_references(self, doctree, fromdocname, builder):
         # type: (nodes.Node, unicode, Builder) -> None
-        for node in doctree.traverse(addnodes.pending_xref):
-            contnode = node[0].deepcopy()
-            newnode = None
-
-            typ = node['reftype']
-            target = node['reftarget']
-            refdoc = node.get('refdoc', fromdocname)
-            domain = None
-
-            try:
-                if 'refdomain' in node and node['refdomain']:
-                    # let the domain try to resolve the reference
-                    try:
-                        domain = self.domains[node['refdomain']]
-                    except KeyError:
-                        raise NoUri
-                    newnode = domain.resolve_xref(self, refdoc, builder,
-                                                  typ, target, node, contnode)
-                # really hardwired reference types
-                elif typ == 'any':
-                    newnode = self._resolve_any_reference(builder, refdoc, node, contnode)
-                # no new node found? try the missing-reference event
-                if newnode is None:
-                    newnode = builder.app.emit_firstresult(
-                        'missing-reference', self, node, contnode)
-                    # still not found? warn if node wishes to be warned about or
-                    # we are in nit-picky mode
-                    if newnode is None:
-                        self._warn_missing_reference(refdoc, typ, target, node, domain)
-            except NoUri:
-                newnode = contnode
-            node.replace_self(newnode or contnode)
+        # apply all post-transforms
+        try:
+            # set env.docname during applying post-transforms
+            self.temp_data['docname'] = fromdocname
+
+            transformer = SphinxTransformer(doctree)
+            transformer.add_transforms(self.app.post_transforms)
+            transformer.apply_transforms()
+        finally:
+            self.temp_data.clear()
 
         # remove only-nodes that do not belong to our builder
         process_only_nodes(doctree, builder.tags)
diff --git a/sphinx/transforms/__init__.py b/sphinx/transforms/__init__.py
index f6fc0f18f..7c35e78a1 100644
--- a/sphinx/transforms/__init__.py
+++ b/sphinx/transforms/__init__.py
@@ -10,8 +10,9 @@
 """
 
 from docutils import nodes
-from docutils.transforms import Transform
+from docutils.transforms import Transform, Transformer
 from docutils.transforms.parts import ContentsFilter
+from docutils.utils import new_document
 
 from sphinx import addnodes
 from sphinx.locale import _
@@ -69,6 +70,28 @@ class SphinxTransform(Transform):
         return self.document.settings.env.config
 
 
+class SphinxTransformer(Transformer):
+    """
+    A transformer for Sphinx.
+    """
+
+    document = None  # type: nodes.Node
+
+    def apply_transforms(self):
+        # type: () -> None
+        if isinstance(self.document, nodes.document):
+            Transformer.apply_transforms(self)
+        else:
+            # wrap the target node by document node during transforming
+            try:
+                document = new_document('')
+                document += self.document
+                self.document = document
+                Transformer.apply_transforms(self)
+            finally:
+                self.document = self.document[0]
+
+
 class DefaultSubstitutions(SphinxTransform):
     """
     Replace some substitutions if they aren't defined in the document.
diff --git a/sphinx/transforms/post_transforms.py b/sphinx/transforms/post_transforms.py
new file mode 100644
index 000000000..9177b0308
--- /dev/null
+++ b/sphinx/transforms/post_transforms.py
@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+"""
+    sphinx.transforms.post_transforms
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    Docutils transforms used by Sphinx.
+
+    :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+from sphinx import addnodes
+from sphinx.environment import NoUri
+from sphinx.transforms import SphinxTransform
+
+if False:
+    # For type annotation
+    from typing import Any, Dict  # NOQA
+    from sphinx.application import Sphinx  # NOQA
+
+
+class ReferencesResolver(SphinxTransform):
+    """
+    Resolves cross-references on doctrees.
+    """
+
+    default_priority = 10
+
+    def apply(self):
+        # type: () -> None
+        for node in self.document.traverse(addnodes.pending_xref):
+            contnode = node[0].deepcopy()
+            newnode = None
+
+            typ = node['reftype']
+            target = node['reftarget']
+            refdoc = node.get('refdoc', self.env.docname)
+            domain = None
+
+            try:
+                if 'refdomain' in node and node['refdomain']:
+                    # let the domain try to resolve the reference
+                    try:
+                        domain = self.env.domains[node['refdomain']]
+                    except KeyError:
+                        raise NoUri
+                    newnode = domain.resolve_xref(self.env, refdoc, self.app.builder,
+                                                  typ, target, node, contnode)
+                # really hardwired reference types
+                elif typ == 'any':
+                    newnode = self.env._resolve_any_reference(self.app.builder, refdoc,
+                                                              node, contnode)
+                # no new node found? try the missing-reference event
+                if newnode is None:
+                    newnode = self.app.emit_firstresult('missing-reference', self.env,
+                                                        node, contnode)
+                    # still not found? warn if node wishes to be warned about or
+                    # we are in nit-picky mode
+                    if newnode is None:
+                        self.env._warn_missing_reference(refdoc, typ, target, node, domain)
+            except NoUri:
+                newnode = contnode
+            node.replace_self(newnode or contnode)
+
+
+def setup(app):
+    # type: (Sphinx) -> Dict[unicode, Any]
+    app.add_post_transform(ReferencesResolver)
+
+    return {
+        'version': 'builtin',
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }