add support for line numbering in the viewcode extention

doc/usage/extensions/viewcode.rst

@@ -73,6 +73,14 @@ Configuration
       `epubcheck <https://github.com/IDPF/epubcheck>`_'s score
       becomes worse even if the reader supports.
 
+.. confval:: viewcode_show_lineos
+
+   If this is ``True``, viewcode extension will display line numbers on the page.
+
+   The default is ``False``.
+
+   .. versionadded:: 6.2
+
 .. event:: viewcode-find-source (app, modname)
 
    .. versionadded:: 1.8

sphinx/ext/viewcode.py

@@ -250,12 +250,16 @@ def collect_pages(app: Sphinx) -> Generator[tuple[str, dict[str, Any], str], Non
             lexer = env.config.highlight_language
         else:
             lexer = 'python'
-        highlighted = highlighter.highlight_block(code, lexer, linenos=False)
+        show_lineos = env.config.viewcode_show_lineos
+        highlighted = highlighter.highlight_block(code, lexer, linenos=show_lineos)
         # split the code into lines
         lines = highlighted.splitlines()
+        # find the first line of code. 0 if it's not nested in a table
+        # skip all row number and search for 2nd <td> if lineos are shown (class="code")
+        offset = next((i for i, line in enumerate(lines) if '<td class="code">' in line), 0)
         # split off wrap markup from the first line of the actual code
-        before, after = lines[0].split('<pre>')
-        lines[0:1] = [before + '<pre>', after]
+        before, after = lines[offset].split('<pre>')
+        lines[offset:offset+1] = [before + '<pre>', after]
         # nothing to do for the last line; it always starts with </pre> anyway
         # now that we have code lines (starting at index 1), insert anchors for
         # the collected tags (HACK: this only works if the tag boundaries are
@@ -264,11 +268,11 @@ def collect_pages(app: Sphinx) -> Generator[tuple[str, dict[str, Any], str], Non
         for name, docname in used.items():
             type, start, end = tags[name]
             backlink = urito(pagename, docname) + '#' + refname + '.' + name
-            lines[start] = (
+            lines[start+offset] = (
                 '<div class="viewcode-block" id="%s"><a class="viewcode-back" '
                 'href="%s">%s</a>' % (name, backlink, _('[docs]')) +
-                lines[start])
-            lines[min(end, maxindex)] += '</div>'
+                lines[start+offset])
+            lines[min(end+offset, maxindex)] += '</div>'
         # try to find parents (for submodules)
         parents = []
         parent = modname
@@ -324,6 +328,7 @@ def setup(app: Sphinx) -> dict[str, Any]:
     app.add_config_value('viewcode_import', None, False)
     app.add_config_value('viewcode_enable_epub', False, False)
     app.add_config_value('viewcode_follow_imported_members', True, False)
+    app.add_config_value('viewcode_show_lineos', False, False)
     app.connect('doctree-read', doctree_read)
     app.connect('env-merge-info', env_merge_info)
     app.connect('env-purge-doc', env_purge_doc)

tests/roots/test-ext-viewcode-lineos/conf.py

@@ -0,0 +1,9 @@
+import os
+import sys
+
+source_dir = os.path.abspath('.')
+if source_dir not in sys.path:
+    sys.path.insert(0, source_dir)
+extensions = ['sphinx.ext.autodoc', 'sphinx.ext.viewcode']
+exclude_patterns = ['_build']
+viewcode_show_lineos = True

tests/roots/test-ext-viewcode-lineos/index.rst

@@ -0,0 +1,39 @@
+viewcode
+========
+
+.. py:module:: spam
+
+.. autofunction:: func1
+
+.. autofunction:: func2
+
+.. autofunction:: spam.mod1.func1
+
+.. autofunction:: spam.mod2.func2
+
+.. autofunction:: Class1
+
+.. autofunction:: Class2
+
+.. autofunction:: spam.mod1.Class1
+
+.. autofunction:: spam.mod2.Class2
+
+
+.. literalinclude:: spam/__init__.py
+   :language: python
+   :pyobject: func1
+
+.. literalinclude:: spam/mod1.py
+   :language: python
+   :pyobject: func1
+
+.. autoclass:: spam.mod3.Class3
+   :members:
+
+.. automodule:: spam.mod3
+   :members:
+
+.. toctree::
+
+   objects

tests/roots/test-ext-viewcode-lineos/objects.rst

@@ -0,0 +1,169 @@
+Testing object descriptions
+===========================
+
+.. function:: func_without_module(a, b, *c[, d])
+
+   Does something.
+
+.. function:: func_without_body()
+
+.. function:: func_noindex
+   :noindex:
+
+.. function:: func_with_module
+   :module: foolib
+
+Referring to :func:`func with no index <func_noindex>`.
+Referring to :func:`nothing <>`.
+
+.. module:: mod
+   :synopsis: Module synopsis.
+   :platform: UNIX
+
+.. function:: func_in_module
+
+.. class:: Cls
+
+   .. method:: meth1
+
+   .. staticmethod:: meths
+
+   .. attribute:: attr
+
+.. explicit class given
+.. method:: Cls.meth2
+
+.. explicit module given
+.. exception:: Error(arg1, arg2)
+   :module: errmod
+
+.. data:: var
+
+
+.. currentmodule:: None
+
+.. function:: func_without_module2() -> annotation
+
+.. object:: long(parameter, \
+              list)
+            another one
+
+.. class:: TimeInt
+
+   Has only one parameter (triggers special behavior...)
+
+   :param moo: |test|
+   :type moo: |test|
+
+.. |test| replace:: Moo
+
+.. class:: Time(hour, minute, isdst)
+
+   :param year: The year.
+   :type year: TimeInt
+   :param TimeInt minute: The minute.
+   :param isdst: whether it's DST
+   :type isdst: * some complex
+                * expression
+   :returns: a new :class:`Time` instance
+   :rtype: :class:`Time`
+   :raises ValueError: if the values are out of range
+   :ivar int hour: like *hour*
+   :ivar minute: like *minute*
+   :vartype minute: int
+   :param hour: Some parameter
+   :type hour: DuplicateType
+   :param hour: Duplicate param.  Should not lead to crashes.
+   :type hour: DuplicateType
+   :param .Cls extcls: A class from another module.
+
+
+C items
+=======
+
+.. c:function:: Sphinx_DoSomething()
+
+.. c:member:: SphinxStruct.member
+
+.. c:macro:: SPHINX_USE_PYTHON
+
+.. c:type:: SphinxType
+
+.. c:var:: sphinx_global
+
+
+Javascript items
+================
+
+.. js:function:: foo()
+
+.. js:data:: bar
+
+.. documenting the method of any object
+.. js:function:: bar.baz(href, callback[, errback])
+
+   :param string href: The location of the resource.
+   :param callback: Gets called with the data returned by the resource.
+   :throws InvalidHref: If the `href` is invalid.
+   :returns: `undefined`
+
+.. js:attribute:: bar.spam
+
+References
+==========
+
+Referencing :class:`mod.Cls` or :Class:`mod.Cls` should be the same.
+
+With target: :c:func:`Sphinx_DoSomething()` (parentheses are handled),
+:c:member:`SphinxStruct.member`, :c:macro:`SPHINX_USE_PYTHON`,
+:c:type:`SphinxType *` (pointer is handled), :c:data:`sphinx_global`.
+
+Without target: :c:func:`CFunction`. :c:func:`!malloc`.
+
+:js:func:`foo()`
+:js:func:`foo`
+
+:js:data:`bar`
+:js:func:`bar.baz()`
+:js:func:`bar.baz`
+:js:func:`~bar.baz()`
+
+:js:attr:`bar.baz`
+
+
+Others
+======
+
+.. envvar:: HOME
+
+.. program:: python
+
+.. cmdoption:: -c command
+
+.. program:: perl
+
+.. cmdoption:: -c
+
+.. option:: +p
+
+Link to :option:`perl +p`.
+
+
+User markup
+===========
+
+.. userdesc:: myobj:parameter
+
+   Description of userdesc.
+
+
+Referencing :userdescrole:`myobj`.
+
+
+CPP domain
+==========
+
+.. cpp:class:: n::Array<T,d>
+
+   .. cpp:function:: T& operator[]( unsigned j )
+                     const T& operator[]( unsigned j ) const

tests/roots/test-ext-viewcode-lineos/spam/__init__.py

@@ -0,0 +1,2 @@
+from .mod1 import Class1, func1
+from .mod2 import Class2, func2

tests/roots/test-ext-viewcode-lineos/spam/mod1.py

@@ -0,0 +1,30 @@
+"""
+mod1
+"""
+
+
+def decorator(f):
+    return f
+
+
+@decorator
+def func1(a, b):
+    """
+    this is func1
+    """
+    return a, b
+
+
+@decorator
+class Class1:
+    """
+    this is Class1
+    """
+
+
+class Class3:
+    """
+    this is Class3
+    """
+    class_attr = 42
+    """this is the class attribute class_attr"""

tests/roots/test-ext-viewcode-lineos/spam/mod2.py

@@ -0,0 +1,22 @@
+"""
+mod2
+"""
+
+
+def decorator(f):
+    return f
+
+
+@decorator
+def func2(a, b):
+    """
+    this is func2
+    """
+    return a, b
+
+
+@decorator
+class Class2:
+    """
+    this is Class2
+    """

tests/roots/test-ext-viewcode-lineos/spam/mod3.py

@@ -0,0 +1,3 @@
+from spam.mod1 import Class3
+
+__all__ = ('Class3',)