Change extension setup() return value to a dictionary of metadata.

This makes it possible to introduce more metadata values later.

doc/extdev/index.rst

@@ -18,15 +18,25 @@ imports this module and executes its ``setup()`` function, which in turn
 notifies Sphinx of everything the extension offers -- see the extension tutorial
 for examples.
 
-.. versionadded:: 1.3
-   The ``setup()`` function can return a string, this is treated by Sphinx as
-   the version of the extension and used for informational purposes such as the
-   traceback file when an exception occurs.
-
 The configuration file itself can be treated as an extension if it contains a
 ``setup()`` function.  All other extensions to load must be listed in the
 :confval:`extensions` configuration value.
 
+Extension metadata
+------------------
+
+.. versionadded:: 1.3
+
+The ``setup()`` function can return a dictionary.  This is treated by Sphinx
+as metadata of the extension.  Metadata keys currently recognized are:
+
+* ``'version'``: a string that identifies the extension version.  It is used for
+  extension version requirement checking (see :confval:`needs_extensions`) and
+  informational purposes.  If not given, ``"unknown version"`` is substituted.
+
+APIs used for writing extensions
+--------------------------------
+
 .. toctree::
 
    tutorial

doc/extdev/tutorial.rst

@@ -162,7 +162,7 @@ new Python module called :file:`todo.py` and add the setup function::
        app.connect('doctree-resolved', process_todo_nodes)
        app.connect('env-purge-doc', purge_todos)
 
-       return '0.1'   # identifies the version of our extension
+       return {'version': '0.1'}   # identifies the version of our extension
 
 The calls in this function refer to classes and functions not yet written.  What
 the individual calls do is the following:

sphinx/application.py

@@ -73,7 +73,7 @@ class Sphinx(object):
         self.verbosity = verbosity
         self.next_listener_id = 0
         self._extensions = {}
-        self._extension_versions = {}
+        self._extension_metadata = {}
         self._listeners = {}
         self.domains = BUILTIN_DOMAINS.copy()
         self.builderclasses = BUILTIN_BUILDERS.copy()
@@ -129,7 +129,7 @@ class Sphinx(object):
             self.setup_extension(extension)
         # the config file itself can be an extension
         if self.config.setup:
-            # py31 doesn't have 'callable' function for bellow check
+            # py31 doesn't have 'callable' function for below check
             if hasattr(self.config.setup, '__call__'):
                 self.config.setup(self)
             else:
@@ -157,7 +157,7 @@ class Sphinx(object):
                               'version requirement for extension %s, but it is '
                               'not loaded' % extname)
                     continue
-                has_ver = self._extension_versions[extname]
+                has_ver = self._extension_metadata[extname]['version']
                 if has_ver == 'unknown version' or needs_ver > has_ver:
                     raise VersionRequirementError(
                         'This project needs the extension %s at least in '
@@ -367,20 +367,22 @@ class Sphinx(object):
         if not hasattr(mod, 'setup'):
             self.warn('extension %r has no setup() function; is it really '
                       'a Sphinx extension module?' % extension)
-            version = None
+            ext_meta = None
         else:
             try:
-                version = mod.setup(self)
+                ext_meta = mod.setup(self)
             except VersionRequirementError as err:
                 # add the extension name to the version required
                 raise VersionRequirementError(
                     'The %s extension used by this project needs at least '
                     'Sphinx v%s; it therefore cannot be built with this '
                     'version.' % (extension, err))
-        if version is None:
-            version = 'unknown version'
+        if ext_meta is None:
+            ext_meta = {}
+        if not ext_meta.get('version'):
+            ext_meta['version'] = 'unknown version'
         self._extensions[extension] = mod
-        self._extension_versions[extension] = version
+        self._extension_metadata[extension] = ext_meta
 
     def require_sphinx(self, version):
         # check the Sphinx version if requested

sphinx/ext/autodoc.py

@@ -1515,7 +1515,7 @@ def setup(app):
     app.add_event('autodoc-process-signature')
     app.add_event('autodoc-skip-member')
 
-    return sphinx.__version__
+    return {'version': sphinx.__version__}
 
 
 class testcls:

sphinx/ext/autosummary/__init__.py

@@ -570,4 +570,4 @@ def setup(app):
     app.connect('doctree-read', process_autosummary_toc)
     app.connect('builder-inited', process_generate_options)
     app.add_config_value('autosummary_generate', [], True)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/coverage.py

@@ -265,4 +265,4 @@ def setup(app):
     app.add_config_value('coverage_ignore_c_items', {}, False)
     app.add_config_value('coverage_write_headline', True, False)
     app.add_config_value('coverage_skip_undoc_in_source', False, False)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/doctest.py

@@ -443,4 +443,4 @@ def setup(app):
     app.add_config_value('doctest_test_doctest_blocks', 'default', False)
     app.add_config_value('doctest_global_setup', '', False)
     app.add_config_value('doctest_global_cleanup', '', False)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/extlinks.py

@@ -59,4 +59,4 @@ def setup_link_roles(app):
 def setup(app):
     app.add_config_value('extlinks', {}, 'env')
     app.connect('builder-inited', setup_link_roles)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/graphviz.py

@@ -323,4 +323,4 @@ def setup(app):
     app.add_config_value('graphviz_dot', 'dot', 'html')
     app.add_config_value('graphviz_dot_args', [], 'html')
     app.add_config_value('graphviz_output_format', 'png', 'html')
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/ifconfig.py

@@ -73,4 +73,4 @@ def setup(app):
     app.add_node(ifconfig)
     app.add_directive('ifconfig', IfConfig)
     app.connect('doctree-resolved', process_ifconfig_nodes)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/inheritance_diagram.py

@@ -408,4 +408,4 @@ def setup(app):
     app.add_config_value('inheritance_graph_attrs', {}, False),
     app.add_config_value('inheritance_node_attrs', {}, False),
     app.add_config_value('inheritance_edge_attrs', {}, False),
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/intersphinx.py

@@ -282,4 +282,4 @@ def setup(app):
     app.add_config_value('intersphinx_cache_limit', 5, False)
     app.connect('missing-reference', missing_reference)
     app.connect('builder-inited', load_mappings)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/jsmath.py

@@ -57,4 +57,4 @@ def setup(app):
     mathbase_setup(app, (html_visit_math, None), (html_visit_displaymath, None))
     app.add_config_value('jsmath_path', '', False)
     app.connect('builder-inited', builder_inited)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/linkcode.py

@@ -71,4 +71,4 @@ def doctree_read(app, doctree):
 def setup(app):
     app.connect('doctree-read', doctree_read)
     app.add_config_value('linkcode_resolve', None, '')
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/mathjax.py

@@ -69,4 +69,4 @@ def setup(app):
     app.add_config_value('mathjax_inline', [r'\(', r'\)'], 'html')
     app.add_config_value('mathjax_display', [r'\[', r'\]'], 'html')
     app.connect('builder-inited', builder_inited)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/napoleon/__init__.py

@@ -256,7 +256,7 @@ def setup(app):
 
     for name, (default, rebuild) in iteritems(Config._config_values):
         app.add_config_value(name, default, rebuild)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}
 
 
 def _process_docstring(app, what, name, obj, options, lines):

sphinx/ext/pngmath.py

@@ -246,4 +246,4 @@ def setup(app):
     app.add_config_value('pngmath_latex_preamble', '', 'html')
     app.add_config_value('pngmath_add_tooltips', True, 'html')
     app.connect('build-finished', cleanup_tempdir)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/todo.py

@@ -172,4 +172,4 @@ def setup(app):
     app.connect('doctree-read', process_todos)
     app.connect('doctree-resolved', process_todo_nodes)
     app.connect('env-purge-doc', purge_todos)
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/ext/viewcode.py

@@ -204,4 +204,4 @@ def setup(app):
     app.connect('missing-reference', missing_reference)
     #app.add_config_value('viewcode_include_modules', [], 'env')
     #app.add_config_value('viewcode_exclude_modules', [], 'env')
-    return sphinx.__version__
+    return {'version': sphinx.__version__}

sphinx/util/__init__.py

@@ -205,7 +205,7 @@ def save_traceback(app):
             if isinstance(modfile, bytes):
                 modfile = modfile.decode(fs_encoding, 'replace')
             os.write(fd, ('#   %s (%s) from %s\n' % (
-                extname, app._extension_versions[extname],
+                extname, app._extension_metadata[extname]['version'],
                 modfile)).encode('utf-8'))
     os.write(fd, exc.encode('utf-8'))
     os.close(fd)