Big i18n tools update, I/II.

Notes:
* Everything is still a bit raw and sometimes hackish.
* Not every feature implemented yet.
* A bunch of cleanup is still needed.
* Doc needs to be updated too!

1 files changed, 891 insertions, 0 deletions

diff --git a/release/scripts/modules/bl_i18n_utils/bl_extract_messages.py b/release/scripts/modules/bl_i18n_utils/bl_extract_messages.py
new file mode 100644
index 00000000000..5287bcdbeb5
--- /dev/null
+++ b/release/scripts/modules/bl_i18n_utils/bl_extract_messages.py
@@ -0,0 +1,891 @@
+# ***** BEGIN GPL LICENSE BLOCK *****
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ***** END GPL LICENSE BLOCK *****
+
+# <pep8 compliant>
+
+# Populate a template file (POT format currently) from Blender RNA/py/C data.
+# XXX: This script is meant to be used from inside Blender!
+#      You should not directly use this script, rather use update_msg.py!
+
+import collections
+import copy
+import datetime
+import os
+import re
+import sys
+
+# XXX Relative import does not work here when used from Blender...
+from bl_i18n_utils import settings as i18n_settings, utils
+
+import bpy
+
+##### Utils #####
+
+# check for strings like "+%f°"
+ignore_reg = re.compile(r"^(?:[-*.()/\\+%°0-9]|%d|%f|%s|%r|\s)*$")
+filter_message = ignore_reg.match
+
+
+def init_spell_check(settings, lang="en_US"):
+    try:
+        from bl_i18n_utils import spell_check_utils
+        return spell_check_utils.SpellChecker(settings, lang)
+    except Exception as e:
+        print("Failed to import spell_check_utils ({})".format(str(e)))
+        return None
+
+
+def _gen_check_ctxt(settings):
+    return {
+        "multi_rnatip": set(),
+        "multi_lines": set(),
+        "py_in_rna": set(),
+        "not_capitalized": set(),
+        "end_point": set(),
+        "undoc_ops": set(),
+        "spell_checker": init_spell_check(settings),
+        "spell_errors": {},
+    }
+
+
+def _gen_reports(check_ctxt):
+    return {
+        "check_ctxt": check_ctxt,
+        "rna_structs": [],
+        "rna_structs_skipped": [],
+        "rna_props": [],
+        "rna_props_skipped": [],
+        "py_messages": [],
+        "py_messages_skipped": [],
+        "src_messages": [],
+        "src_messages_skipped": [],
+        "messages_skipped": set(),
+    }
+
+
+def check(check_ctxt, msgs, key, msgsrc, settings):
+    """
+    Performs a set of checks over the given key (context, message)...
+    """
+    if check_ctxt is None:
+        return
+    multi_rnatip = check_ctxt.get("multi_rnatip")
+    multi_lines = check_ctxt.get("multi_lines")
+    py_in_rna = check_ctxt.get("py_in_rna")
+    not_capitalized = check_ctxt.get("not_capitalized")
+    end_point = check_ctxt.get("end_point")
+    undoc_ops = check_ctxt.get("undoc_ops")
+    spell_checker = check_ctxt.get("spell_checker")
+    spell_errors = check_ctxt.get("spell_errors")
+
+    if multi_rnatip is not None:
+        if key in msgs and key not in multi_rnatip:
+            multi_rnatip.add(key)
+    if multi_lines is not None:
+        if '\n' in key[1]:
+            multi_lines.add(key)
+    if py_in_rna is not None:
+        if key in py_in_rna[1]:
+            py_in_rna[0].add(key)
+    if not_capitalized is not None:
+        if(key[1] not in settings.WARN_MSGID_NOT_CAPITALIZED_ALLOWED and
+           key[1][0].isalpha() and not key[1][0].isupper()):
+            not_capitalized.add(key)
+    if end_point is not None:
+        if (key[1].strip().endswith('.') and not key[1].strip().endswith('...') and
+            key[1] not in settings.WARN_MSGID_END_POINT_ALLOWED):
+            end_point.add(key)
+    if undoc_ops is not None:
+        if key[1] == settings.UNDOC_OPS_STR:
+            undoc_ops.add(key)
+    if spell_checker is not None and spell_errors is not None:
+        err = spell_checker.check(key[1])
+        if err:
+            spell_errors[key] = err
+
+
+def print_info(reports, pot):
+    def _print(*args, **kwargs):
+        kwargs["file"] = sys.stderr
+        print(*args, **kwargs)
+
+    pot.update_info()
+
+    _print("{} RNA structs were processed (among which {} were skipped), containing {} RNA properties "
+           "(among which {} were skipped).".format(len(reports["rna_structs"]), len(reports["rna_structs_skipped"]),
+                                                   len(reports["rna_props"]), len(reports["rna_props_skipped"])))
+    _print("{} messages were extracted from Python UI code (among which {} were skipped), and {} from C source code "
+           "(among which {} were skipped).".format(len(reports["py_messages"]), len(reports["py_messages_skipped"]),
+                                                   len(reports["src_messages"]), len(reports["src_messages_skipped"])))
+    _print("{} messages were rejected.".format(len(reports["messages_skipped"])))
+    _print("\n")
+    _print("Current POT stats:")
+    pot.print_stats(prefix="\t", output=_print)
+    _print("\n")
+
+    check_ctxt = reports["check_ctxt"]
+    if check_ctxt is None:
+        return
+    multi_rnatip = check_ctxt.get("multi_rnatip")
+    multi_lines = check_ctxt.get("multi_lines")
+    py_in_rna = check_ctxt.get("py_in_rna")
+    not_capitalized = check_ctxt.get("not_capitalized")
+    end_point = check_ctxt.get("end_point")
+    undoc_ops = check_ctxt.get("undoc_ops")
+    spell_errors = check_ctxt.get("spell_errors")
+
+    # XXX Temp, no multi_rnatip nor py_in_rna, see below.
+    keys = multi_lines | not_capitalized | end_point | undoc_ops | spell_errors.keys()
+    if keys:
+        _print("WARNINGS:")
+        for key in keys:
+            if undoc_ops and key in undoc_ops:
+                _print("\tThe following operators are undocumented!")
+            else:
+                _print("\t“{}”|“{}”:".format(*key))
+                if multi_lines and key in multi_lines:
+                    _print("\t\t-> newline in this message!")
+                if not_capitalized and key in not_capitalized:
+                    _print("\t\t-> message not capitalized!")
+                if end_point and key in end_point:
+                    _print("\t\t-> message with endpoint!")
+                # XXX Hide this one for now, too much false positives.
+#                if multi_rnatip and key in multi_rnatip:
+#                    _print("\t\t-> tip used in several RNA items")
+#                if py_in_rna and key in py_in_rna:
+#                    _print("\t\t-> RNA message also used in py UI code!")
+                if spell_errors and spell_errors.get(key):
+                    lines = ["\t\t-> {}: misspelled, suggestions are ({})".format(w, "'" + "', '".join(errs) + "'")
+                             for w, errs in  spell_errors[key]]
+                    _print("\n".join(lines))
+            _print("\t\t{}".format("\n\t\t".join(pot.msgs[key].sources)))
+
+
+def enable_addons(addons={}, support={}, disable=False):
+    """
+    Enable (or disable) addons based either on a set of names, or a set of 'support' types.
+    Returns the list of all affected addons (as fake modules)!
+    """
+    import addon_utils
+
+    userpref = bpy.context.user_preferences
+    used_ext = {ext.module for ext in userpref.addons}
+
+    ret = [mod for mod in addon_utils.modules(addon_utils.addons_fake_modules)
+               if ((addons and mod.__name__ in addons) or
+                   (not addons and addon_utils.module_bl_info(mod)["support"] in support))]
+
+    for mod in ret:
+        module_name = mod.__name__
+        if disable:
+            if module_name not in used_ext:
+                continue
+            print("    Disabling module ", module_name)
+            bpy.ops.wm.addon_disable(module=module_name)
+        else:
+            if module_name in used_ext:
+                continue
+            print("    Enabling module ", module_name)
+            bpy.ops.wm.addon_enable(module=module_name)
+
+    # XXX There are currently some problems with bpy/rna...
+    #     *Very* tricky to solve!
+    #     So this is a hack to make all newly added operator visible by
+    #     bpy.types.OperatorProperties.__subclasses__()
+    for cat in dir(bpy.ops):
+        cat = getattr(bpy.ops, cat)
+        for op in dir(cat):
+            getattr(cat, op).get_rna()
+
+    return ret
+
+
+def process_msg(msgs, msgctxt, msgid, msgsrc, reports, check_ctxt, settings):
+    if filter_message(msgid):
+        reports["messages_skipped"].add((msgid, msgsrc))
+        return
+    if not msgctxt:
+        # We do *not* want any "" context!
+        msgctxt = settings.DEFAULT_CONTEXT
+    # Always unescape keys!
+    msgctxt = utils.I18nMessage.do_unescape(msgctxt)
+    msgid = utils.I18nMessage.do_unescape(msgid)
+    key = (msgctxt, msgid)
+    check(check_ctxt, msgs, key, msgsrc, settings)
+    msgsrc = settings.PO_COMMENT_PREFIX_SOURCE_CUSTOM + msgsrc
+    if key not in msgs:
+        msgs[key] = utils.I18nMessage([msgctxt], [msgid], [], [msgsrc], settings=settings)
+    else:
+        msgs[key].comment_lines.append(msgsrc)
+
+
+##### RNA #####
+def dump_messages_rna(msgs, reports, settings):
+    """
+    Dump into messages dict all RNA-defined UI messages (labels en tooltips).
+    """
+    def class_blacklist():
+        blacklist_rna_class = [
+            # core classes
+            "Context", "Event", "Function", "UILayout", "BlendData", "UnknownType",
+            # registerable classes
+            "Panel", "Menu", "Header", "RenderEngine", "Operator", "OperatorMacro", "Macro", "KeyingSetInfo",
+            # window classes
+            "Window",
+        ]
+
+        # Collect internal operators
+        # extend with all internal operators
+        # note that this uses internal api introspection functions
+        # all possible operator names
+        op_ids = set(cls.bl_rna.identifier for cls in bpy.types.OperatorProperties.__subclasses__()) | \
+                 set(cls.bl_rna.identifier for cls in bpy.types.Operator.__subclasses__()) | \
+                 set(cls.bl_rna.identifier for cls in bpy.types.OperatorMacro.__subclasses__())
+
+        get_instance = __import__("_bpy").ops.get_instance
+#        path_resolve = type(bpy.context).__base__.path_resolve
+        for idname in op_ids:
+            op = get_instance(idname)
+            # XXX Do not skip INTERNAL's anymore, some of those ops show up in UI now!
+#            if 'INTERNAL' in path_resolve(op, "bl_options"):
+#                blacklist_rna_class.append(idname)
+
+        # Collect builtin classes we don't need to doc
+        blacklist_rna_class.append("Property")
+        blacklist_rna_class.extend([cls.__name__ for cls in bpy.types.Property.__subclasses__()])
+
+        # Collect classes which are attached to collections, these are api access only.
+        collection_props = set()
+        for cls_id in dir(bpy.types):
+            cls = getattr(bpy.types, cls_id)
+            for prop in cls.bl_rna.properties:
+                if prop.type == 'COLLECTION':
+                    prop_cls = prop.srna
+                    if prop_cls is not None:
+                        collection_props.add(prop_cls.identifier)
+        blacklist_rna_class.extend(sorted(collection_props))
+
+        return blacklist_rna_class
+
+    check_ctxt_rna = check_ctxt_rna_tip = None
+    check_ctxt = reports["check_ctxt"]
+    if check_ctxt:
+        check_ctxt_rna = {
+            "multi_lines": check_ctxt.get("multi_lines"),
+            "not_capitalized": check_ctxt.get("not_capitalized"),
+            "end_point": check_ctxt.get("end_point"),
+            "undoc_ops": check_ctxt.get("undoc_ops"),
+            "spell_checker": check_ctxt.get("spell_checker"),
+            "spell_errors": check_ctxt.get("spell_errors"),
+        }
+        check_ctxt_rna_tip = check_ctxt_rna
+        check_ctxt_rna_tip["multi_rnatip"] = check_ctxt.get("multi_rnatip")
+
+    default_context = settings.DEFAULT_CONTEXT
+
+    # Function definitions
+    def walk_properties(cls):
+        bl_rna = cls.bl_rna
+        # Get our parents' properties, to not export them multiple times.
+        bl_rna_base = bl_rna.base
+        if bl_rna_base:
+            bl_rna_base_props = set(bl_rna_base.properties.values())
+        else:
+            bl_rna_base_props = set()
+
+        for prop in bl_rna.properties:
+            # Only write this property if our parent hasn't got it.
+            if prop in bl_rna_base_props:
+                continue
+            if prop.identifier == "rna_type":
+                continue
+            reports["rna_props"].append((cls, prop))
+
+            msgsrc = "bpy.types.{}.{}".format(bl_rna.identifier, prop.identifier)
+            msgctxt = prop.translation_context or default_context
+
+            if prop.name and (prop.name != prop.identifier or msgctxt != default_context):
+                process_msg(msgs, msgctxt, prop.name, msgsrc, reports, check_ctxt_rna, settings)
+            if prop.description:
+                process_msg(msgs, default_context, prop.description, msgsrc, reports, check_ctxt_rna_tip, settings)
+
+            if isinstance(prop, bpy.types.EnumProperty):
+                for item in prop.enum_items:
+                    msgsrc = "bpy.types.{}.{}:'{}'".format(bl_rna.identifier, prop.identifier, item.identifier)
+                    if item.name and item.name != item.identifier:
+                        process_msg(msgs, msgctxt, item.name, msgsrc, reports, check_ctxt_rna, settings)
+                    if item.description:
+                        process_msg(msgs, default_context, item.description, msgsrc, reports, check_ctxt_rna_tip,
+                                    settings)
+
+    blacklist_rna_class = class_blacklist()
+
+    def walk_class(cls):
+        bl_rna = cls.bl_rna
+        reports["rna_structs"].append(cls)
+        if bl_rna.identifier in blacklist_rna_class:
+            reports["rna_structs_skipped"].append(cls)
+            return
+
+        # XXX translation_context of Operator sub-classes are not "good"!
+        #     So ignore those Operator sub-classes (anyway, will get the same from OperatorProperties sub-classes!)...
+        if issubclass(cls, bpy.types.Operator):
+            reports["rna_structs_skipped"].append(cls)
+            return
+
+        msgsrc = "bpy.types." + bl_rna.identifier
+        msgctxt = bl_rna.translation_context or default_context
+
+        if bl_rna.name and (bl_rna.name != bl_rna.identifier or msgctxt != default_context):
+            process_msg(msgs, msgctxt, bl_rna.name, msgsrc, reports, check_ctxt_rna, settings)
+
+        if bl_rna.description:
+            process_msg(msgs, default_context, bl_rna.description, msgsrc, reports, check_ctxt_rna_tip, settings)
+
+        if hasattr(bl_rna, 'bl_label') and  bl_rna.bl_label:
+            process_msg(msgs, msgctxt, bl_rna.bl_label, msgsrc, reports, check_ctxt_rna, settings)
+
+        walk_properties(cls)
+
+    def walk_keymap_hierarchy(hier, msgsrc_prev):
+        for lvl in hier:
+            msgsrc = msgsrc_prev + "." + lvl[1]
+            process_msg(msgs, default_context, lvl[0], msgsrc, reports, None, settings)
+            if lvl[3]:
+                walk_keymap_hierarchy(lvl[3], msgsrc)
+
+    # Dump Messages
+    def process_cls_list(cls_list):
+        if not cls_list:
+            return
+
+        def full_class_id(cls):
+            """ gives us 'ID.Lamp.AreaLamp' which is best for sorting."""
+            cls_id = ""
+            bl_rna = cls.bl_rna
+            while bl_rna:
+                cls_id = bl_rna.identifier + "." + cls_id
+                bl_rna = bl_rna.base
+            return cls_id
+
+        cls_list.sort(key=full_class_id)
+        for cls in cls_list:
+            walk_class(cls)
+            # Recursively process subclasses.
+            process_cls_list(cls.__subclasses__())
+
+    # Parse everything (recursively parsing from bpy_struct "class"...).
+    process_cls_list(bpy.types.ID.__base__.__subclasses__())
+
+    # And parse keymaps!
+    from bpy_extras.keyconfig_utils import KM_HIERARCHY
+
+    walk_keymap_hierarchy(KM_HIERARCHY, "KM_HIERARCHY")
+
+
+##### Python source code #####
+def dump_py_messages_from_files(msgs, reports, files, settings):
+    """
+    Dump text inlined in the python files given, e.g. 'My Name' in:
+        layout.prop("someprop", text="My Name")
+    """
+    import ast
+
+    bpy_struct = bpy.types.ID.__base__
+
+    # Helper function
+    def extract_strings_ex(node, is_split=False):
+        """
+        Recursively get strings, needed in case we have "Blah" + "Blah", passed as an argument in that case it won't
+        evaluate to a string. However, break on some kind of stopper nodes, like e.g. Subscript.
+        """
+        if type(node) == ast.Str:
+            eval_str = ast.literal_eval(node)
+            if eval_str:
+                yield (is_split, eval_str, (node,))
+        else:
+            is_split = (type(node) in separate_nodes)
+            for nd in ast.iter_child_nodes(node):
+                if type(nd) not in stopper_nodes:
+                    yield from extract_strings_ex(nd, is_split=is_split)
+
+    def _extract_string_merge(estr_ls, nds_ls):
+        return "".join(s for s in estr_ls if s is not None), tuple(n for n in nds_ls if n is not None)
+
+    def extract_strings(node):
+        estr_ls = []
+        nds_ls = []
+        for is_split, estr, nds in extract_strings_ex(node):
+            estr_ls.append(estr)
+            nds_ls.extend(nds)
+        ret = _extract_string_merge(estr_ls, nds_ls)
+        return ret
+    
+    def extract_strings_split(node):
+        """
+        Returns a list args as returned by 'extract_strings()', But split into groups based on separate_nodes, this way
+        expressions like ("A" if test else "B") wont be merged but "A" + "B" will.
+        """
+        estr_ls = []
+        nds_ls = []
+        bag = []
+        for is_split, estr, nds in extract_strings_ex(node):
+            if is_split:
+                bag.append((estr_ls, nds_ls))
+                estr_ls = []
+                nds_ls = []
+
+            estr_ls.append(estr)
+            nds_ls.extend(nds)
+
+        bag.append((estr_ls, nds_ls))
+
+        return [_extract_string_merge(estr_ls, nds_ls) for estr_ls, nds_ls in bag]
+
+
+    def _ctxt_to_ctxt(node):
+        return extract_strings(node)[0]
+
+    def _op_to_ctxt(node):
+        opname, _ = extract_strings(node)
+        if not opname:
+            return settings.DEFAULT_CONTEXT
+        op = bpy.ops
+        for n in opname.split('.'):
+            op = getattr(op, n)
+        try:
+            return op.get_rna().bl_rna.translation_context
+        except Exception as e:
+            default_op_context = bpy.app.translations.contexts.operator_default
+            print("ERROR: ", str(e))
+            print("       Assuming default operator context '{}'".format(default_op_context))
+            return default_op_context
+
+    # Gather function names.
+    # In addition of UI func, also parse pgettext ones...
+    # Tuples of (module name, (short names, ...)).
+    pgettext_variants = (
+        ("pgettext", ("_",)),
+        ("pgettext_iface", ("iface_",)),
+        ("pgettext_tip", ("tip_",))
+    )
+    pgettext_variants_args = {"msgid": (0, {"msgctxt": 1})}
+
+    # key: msgid keywords.
+    # val: tuples of ((keywords,), context_getter_func) to get a context for that msgid.
+    #      Note: order is important, first one wins!
+    translate_kw = {
+        "text": ((("text_ctxt",), _ctxt_to_ctxt),
+                 (("operator",), _op_to_ctxt),
+                ),
+        "msgid": ((("msgctxt",), _ctxt_to_ctxt),
+                 ),
+    }
+
+    context_kw_set = {}
+    for k, ctxts in translate_kw.items():
+        s = set()
+        for c, _ in ctxts:
+            s |= set(c)
+        context_kw_set[k] = s
+
+    # {func_id: {msgid: (arg_pos,
+    #                    {msgctxt: arg_pos,
+    #                     ...
+    #                    }
+    #                   ),
+    #            ...
+    #           },
+    #  ...
+    # }
+    func_translate_args = {}
+
+    # First, functions from UILayout
+    # First loop is for msgid args, second one is for msgctxt args.
+    for func_id, func in bpy.types.UILayout.bl_rna.functions.items():
+        # check it has one or more arguments as defined in translate_kw
+        for arg_pos, (arg_kw, arg) in enumerate(func.parameters.items()):
+            if ((arg_kw in translate_kw) and (not arg.is_output) and (arg.type == 'STRING')):
+                func_translate_args.setdefault(func_id, {})[arg_kw] = (arg_pos, {})
+    for func_id, func in bpy.types.UILayout.bl_rna.functions.items():
+        if func_id not in func_translate_args:
+            continue
+        for arg_pos, (arg_kw, arg) in enumerate(func.parameters.items()):
+            if (not arg.is_output) and (arg.type == 'STRING'):
+                for msgid, msgctxts in context_kw_set.items():
+                    if arg_kw in msgctxts:
+                        func_translate_args[func_id][msgid][1][arg_kw] = arg_pos
+    # We manually add funcs from bpy.app.translations
+    for func_id, func_ids in pgettext_variants:
+        func_translate_args[func_id] = pgettext_variants_args
+        for func_id in func_ids:
+            func_translate_args[func_id] = pgettext_variants_args
+    #print(func_translate_args)
+
+    # Break recursive nodes look up on some kind of nodes.
+    # E.g. we don’t want to get strings inside subscripts (blah["foo"])!
+    stopper_nodes = {ast.Subscript}
+    # Consider strings separate: ("a" if test else "b")
+    separate_nodes = {ast.IfExp}
+
+    check_ctxt_py = None
+    if reports["check_ctxt"]:
+        check_ctxt = reports["check_ctxt"]
+        check_ctxt_py = {
+            "py_in_rna": (check_ctxt.get("py_in_rna"), set(msgs.keys())),
+            "multi_lines": check_ctxt.get("multi_lines"),
+            "not_capitalized": check_ctxt.get("not_capitalized"),
+            "end_point": check_ctxt.get("end_point"),
+            "spell_checker": check_ctxt.get("spell_checker"),
+            "spell_errors": check_ctxt.get("spell_errors"),
+        }
+
+    for fp in files:
+        with open(fp, 'r', encoding="utf8") as filedata:
+            root_node = ast.parse(filedata.read(), fp, 'exec')
+
+        fp_rel = os.path.relpath(fp, settings.SOURCE_DIR)
+
+        for node in ast.walk(root_node):
+            if type(node) == ast.Call:
+                # print("found function at")
+                # print("%s:%d" % (fp, node.lineno))
+
+                # We can't skip such situations! from blah import foo\nfoo("bar") would also be an ast.Name func!
+                if type(node.func) == ast.Name:
+                    func_id = node.func.id
+                elif hasattr(node.func, "attr"):
+                    func_id = node.func.attr
+                # Ugly things like getattr(self, con.type)(context, box, con)
+                else:
+                    continue
+
+                func_args = func_translate_args.get(func_id, {})
+
+                # First try to get i18n contexts, for every possible msgid id.
+                msgctxts = dict.fromkeys(func_args.keys(), "")
+                for msgid, (_, context_args) in func_args.items():
+                    context_elements = {}
+                    for arg_kw, arg_pos in context_args.items():
+                        if arg_pos < len(node.args):
+                            context_elements[arg_kw] = node.args[arg_pos]
+                        else:
+                            for kw in node.keywords:
+                                if kw.arg == arg_kw:
+                                    context_elements[arg_kw] = kw.value
+                                    break
+                    #print(context_elements)
+                    for kws, proc in translate_kw[msgid]:
+                        if set(kws) <= context_elements.keys():
+                            args = tuple(context_elements[k] for k in kws)
+                            #print("running ", proc, " with ", args)
+                            ctxt = proc(*args)
+                            if ctxt:
+                                msgctxts[msgid] = ctxt
+                                break
+
+                #print(translate_args)
+                # do nothing if not found
+                for arg_kw, (arg_pos, _) in func_args.items():
+                    msgctxt = msgctxts[arg_kw]
+                    estr_lst = [(None, ())]
+                    if arg_pos < len(node.args):
+                        estr_lst = extract_strings_split(node.args[arg_pos])
+                        #print(estr, nds)
+                    else:
+                        for kw in node.keywords:
+                            if kw.arg == arg_kw:
+                                estr_lst = extract_strings_split(kw.value)
+                                break
+                        #print(estr, nds)
+                    for estr, nds in estr_lst:
+                        if estr:
+                            if nds:
+                                msgsrc = "{}:{}".format(fp_rel, sorted({nd.lineno for nd in nds})[0])
+                            else:
+                                msgsrc = "{}:???".format(fp_rel)
+                            process_msg(msgs, msgctxt, estr, msgsrc, reports, check_ctxt_py, settings)
+                            reports["py_messages"].append((msgctxt, estr, msgsrc))
+
+
+def dump_py_messages(msgs, reports, addons, settings):
+    def _get_files(path):
+        if os.path.isdir(path):
+            # XXX use walk instead of listdir?
+            return [os.path.join(path, fn) for fn in sorted(os.listdir(path))
+                                              if not fn.startswith("_") and fn.endswith(".py")]
+        return [path]
+
+    files = []
+    for path in settings.CUSTOM_PY_UI_FILES:
+        files += _get_files(path)
+
+    # Add all addons we support in main translation file!
+    for mod in addons:
+        fn = mod.__file__
+        if os.path.basename(fn) == "__init__.py":
+            files += _get_files(os.path.dirname(fn))
+        else:
+            files.append(fn)
+
+    dump_py_messages_from_files(msgs, reports, files, settings)
+
+
+##### C source code #####
+def dump_src_messages(msgs, reports, settings):
+    def get_contexts():
+        """Return a mapping {C_CTXT_NAME: ctxt_value}."""
+        return {k: getattr(bpy.app.translations.contexts, n) for k, n in bpy.app.translations.contexts_C_to_py.items()}
+
+    contexts = get_contexts()
+
+    # Build regexes to extract messages (with optional contexts) from C source.
+    pygettexts = tuple(re.compile(r).search for r in settings.PYGETTEXT_KEYWORDS)
+
+    _clean_str = re.compile(settings.str_clean_re).finditer
+    clean_str = lambda s: "".join(m.group("clean") for m in _clean_str(s))
+
+    def dump_src_file(path, rel_path, msgs, reports, settings):
+        def process_entry(_msgctxt, _msgid):
+            # Context.
+            msgctxt = settings.DEFAULT_CONTEXT
+            if _msgctxt:
+                if _msgctxt in contexts:
+                    msgctxt = contexts[_msgctxt]
+                elif '"' in _msgctxt or "'" in _msgctxt:
+                    msgctxt = clean_str(_msgctxt)
+                else:
+                    print("WARNING: raw context “{}” couldn’t be resolved!".format(_msgctxt))
+            # Message.
+            msgid = ""
+            if _msgid:
+                if '"' in _msgid or "'" in _msgid:
+                    msgid = clean_str(_msgid)
+                else:
+                    print("WARNING: raw message “{}” couldn’t be resolved!".format(_msgid))
+            return msgctxt, msgid
+
+        check_ctxt_src = None
+        if reports["check_ctxt"]:
+            check_ctxt = reports["check_ctxt"]
+            check_ctxt_src = {
+                "multi_lines": check_ctxt.get("multi_lines"),
+                "not_capitalized": check_ctxt.get("not_capitalized"),
+                "end_point": check_ctxt.get("end_point"),
+                "spell_checker": check_ctxt.get("spell_checker"),
+                "spell_errors": check_ctxt.get("spell_errors"),
+            }
+
+        data = ""
+        with open(path) as f:
+            data = f.read()
+        for srch in pygettexts:
+            m = srch(data)
+            line = pos = 0
+            while m:
+                d = m.groupdict()
+                # Line.
+                line += data[pos:m.start()].count('\n')
+                msgsrc = rel_path + ":" + str(line)
+                _msgid = d.get("msg_raw")
+                # First, try the "multi-contexts" stuff!
+                _msgctxts = tuple(d.get("ctxt_raw{}".format(i)) for i in range(settings.PYGETTEXT_MAX_MULTI_CTXT))
+                if _msgctxts[0]:
+                    for _msgctxt in _msgctxts:
+                        if not _msgctxt:
+                            break
+                        msgctxt, msgid = process_entry(_msgctxt, _msgid)
+                        process_msg(msgs, msgctxt, msgid, msgsrc, reports, check_ctxt_src, settings)
+                        reports["src_messages"].append((msgctxt, msgid, msgsrc))
+                else:
+                    _msgctxt = d.get("ctxt_raw")
+                    msgctxt, msgid = process_entry(_msgctxt, _msgid)
+                    process_msg(msgs, msgctxt, msgid, msgsrc, reports, check_ctxt_src, settings)
+                    reports["src_messages"].append((msgctxt, msgid, msgsrc))
+
+                pos = m.end()
+                line += data[m.start():pos].count('\n')
+                m = srch(data, pos)
+
+    forbidden = set()
+    forced = set()
+    if os.path.isfile(settings.SRC_POTFILES):
+        with open(settings.SRC_POTFILES) as src:
+            for l in src:
+                if l[0] == '-':
+                    forbidden.add(l[1:].rstrip('\n'))
+                elif l[0] != '#':
+                    forced.add(l.rstrip('\n'))
+    for root, dirs, files in os.walk(settings.POTFILES_SOURCE_DIR):
+        if "/.svn" in root:
+            continue
+        for fname in files:
+            if os.path.splitext(fname)[1] not in settings.PYGETTEXT_ALLOWED_EXTS:
+                continue
+            path = os.path.join(root, fname)
+            rel_path = os.path.relpath(path, settings.SOURCE_DIR)
+            if rel_path in forbidden:
+                continue
+            elif rel_path not in forced:
+                forced.add(rel_path)
+    for rel_path in sorted(forced):
+        path = os.path.join(settings.SOURCE_DIR, rel_path)
+        if os.path.exists(path):
+            dump_src_file(path, rel_path, msgs, reports, settings)
+
+
+##### Main functions! #####
+def dump_messages(do_messages, do_checks, settings):
+    bl_ver = "Blender " + bpy.app.version_string
+    bl_rev = bpy.app.build_revision
+    bl_date = datetime.datetime.strptime(bpy.app.build_date.decode() + "T" + bpy.app.build_time.decode(),
+                                         "%Y-%m-%dT%H:%M:%S")
+    pot = utils.I18nMessages.gen_empty_messages(settings.PARSER_TEMPLATE_ID, bl_ver, bl_rev, bl_date, bl_date.year,
+                                                settings=settings)
+    msgs = pot.msgs
+
+    # Enable all wanted addons.
+    # For now, enable all official addons, before extracting msgids.
+    addons = enable_addons(support={"OFFICIAL"})
+    # Note this is not needed if we have been started with factory settings, but just in case...
+    enable_addons(support={"COMMUNITY", "TESTING"}, disable=True)
+
+    reports = _gen_reports(_gen_check_ctxt(settings) if do_checks else None)
+
+    # Get strings from RNA.
+    dump_messages_rna(msgs, reports, settings)
+
+    # Get strings from UI layout definitions text="..." args.
+    dump_py_messages(msgs, reports, addons, settings)
+
+    # Get strings from C source code.
+    dump_src_messages(msgs, reports, settings)
+
+    # Get strings specific to translations' menu.
+    for lng in settings.LANGUAGES:
+        process_msg(msgs, settings.DEFAULT_CONTEXT, lng[1], "Languages’ labels from bl_i18n_utils/settings.py",
+                    reports, None, settings)
+    for cat in settings.LANGUAGES_CATEGORIES:
+        process_msg(msgs, settings.DEFAULT_CONTEXT, cat[1],
+                    "Language categories’ labels from bl_i18n_utils/settings.py", reports, None, settings)
+
+    #pot.check()
+    pot.unescape()  # Strings gathered in py/C source code may contain escaped chars...
+    print_info(reports, pot)
+    #pot.check()
+
+    if do_messages:
+        print("Writing messages…")
+        pot.write('PO', settings.FILE_NAME_POT)
+
+    print("Finished extracting UI messages!")
+
+
+def dump_addon_messages(module_name, messages_formats, do_checks, settings):
+    # Enable our addon and get strings from RNA.
+    addon = enable_addons(addons={module_name})[0]
+
+    addon_info = addon_utils.module_bl_info(addon)
+    ver = addon_info.name + " " + ".".join(addon_info.version)
+    rev = "???"
+    date = datetime.datetime()
+    pot = utils.I18nMessages.gen_empty_messages(settings.PARSER_TEMPLATE_ID, ver, rev, date, date.year,
+                                                settings=settings)
+    msgs = pot.msgs
+
+    minus_msgs = copy.deepcopy(msgs)
+
+    check_ctxt = _gen_check_ctxt(settings) if do_checks else None
+    minus_check_ctxt = _gen_check_ctxt(settings) if do_checks else None
+
+    # Get current addon state (loaded or not):
+    was_loaded = addon_utils.check(module_name)[1]
+
+    # Enable our addon and get strings from RNA.
+    addons = enable_addons(addons={module_name})
+    reports = _gen_reports(check_ctxt)
+    dump_messages_rna(msgs, reports, settings)
+
+    # Now disable our addon, and rescan RNA.
+    enable_addons(addons={module_name}, disable=True)
+    reports["check_ctxt"] = minus_check_ctxt
+    dump_messages_rna(minus_msgs, reports, settings)
+
+    # Restore previous state if needed!
+    if was_loaded:
+        enable_addons(addons={module_name})
+
+    # and make the diff!
+    for key in minus_msgs:
+        if key == settings.PO_HEADER_KEY:
+            continue
+        del msgs[key]
+
+    if check_ctxt:
+        for key in check_ctxt:
+            for warning in minus_check_ctxt[key]:
+                check_ctxt[key].remove(warning)
+
+    # and we are done with those!
+    del minus_msgs
+    del minus_check_ctxt
+
+    # get strings from UI layout definitions text="..." args
+    reports["check_ctxt"] = check_ctxt
+    dump_messages_pytext(msgs, reports, addons, settings)
+
+    print_info(reports, pot)
+
+    return pot
+
+
+def main():
+    try:
+        import bpy
+    except ImportError:
+        print("This script must run from inside blender")
+        return
+
+    import sys
+    back_argv = sys.argv
+    # Get rid of Blender args!
+    sys.argv = sys.argv[sys.argv.index("--") + 1:]
+
+    import argparse
+    parser = argparse.ArgumentParser(description="Process UI messages from inside Blender.")
+    parser.add_argument('-c', '--no_checks', default=True, action="store_false", help="No checks over UI messages.")
+    parser.add_argument('-m', '--no_messages', default=True, action="store_false", help="No export of UI messages.")
+    parser.add_argument('-o', '--output', default=None, help="Output POT file path.")
+    parser.add_argument('-s', '--settings', default=None,
+                        help="Override (some) default settings. Either a JSon file name, or a JSon string.")
+    args = parser.parse_args()
+
+    settings = i18n_settings.I18nSettings()
+    settings.from_json(args.settings)
+
+    if args.output:
+        settings.FILE_NAME_POT = args.output
+
+    dump_messages(do_messages=args.no_messages, do_checks=args.no_checks, settings=settings)
+
+    sys.argv = back_argv
+
+
+if __name__ == "__main__":
+    print("\n\n *** Running {} *** \n".format(__file__))
+    main()