#!/usr/bin/env python
#
# Copyright 2016 by Shaheed Haque (srhaque@theiet.org)
# Copyright 2016 by Stephen Kelly (steveire@gmail.com)
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. The name of the author may not be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

"""SIP file generator for PyQt."""

from __future__ import print_function
import argparse
import gettext
import inspect
import logging
import os
import re
import sys
import traceback
from clang import cindex
from clang.cindex import AccessSpecifier, CursorKind, SourceRange, StorageClass, TokenKind, TypeKind, TranslationUnit

import rules_engine


class HelpFormatter(argparse.ArgumentDefaultsHelpFormatter, argparse.RawDescriptionHelpFormatter):
    pass


logger = logging.getLogger(__name__)
gettext.install(__name__)

EXPR_KINDS = [
    CursorKind.UNEXPOSED_EXPR,
    CursorKind.CONDITIONAL_OPERATOR, CursorKind.UNARY_OPERATOR, CursorKind.BINARY_OPERATOR,
    CursorKind.INTEGER_LITERAL, CursorKind.FLOATING_LITERAL, CursorKind.STRING_LITERAL,
    CursorKind.CXX_BOOL_LITERAL_EXPR, CursorKind.CXX_STATIC_CAST_EXPR, CursorKind.DECL_REF_EXPR
]
TEMPLATE_KINDS = [
                     CursorKind.TYPE_REF, CursorKind.TEMPLATE_REF, CursorKind.NAMESPACE_REF
                 ] + EXPR_KINDS

def clang_diagnostic_to_logging_diagnostic(lvl):
    """

    The diagnostic levels in cindex.py are

        Ignored = 0
        Note    = 1
        Warning = 2
        Error   = 3
        Fatal   = 4

    and the leves in the python logging module are

        NOTSET      0
        DEBUG       10
        INFO        20
        WARNING     30
        ERROR       40
        CRITICAL    50

    """
    return (logging.NOTSET,
        logging.INFO,
        logging.WARNING,
        logging.ERROR,
        logging.CRITICAL)[lvl]

def diagnostic_word(lvl):
    return ("", "info", "warning", "error", "fatality")[lvl]

class SipGenerator(object):
    def __init__(self, project_rules, compile_flags, verbose=False, dump_includes=False, dump_privates=False):
        """
        Constructor.

        :param project_rules:       The rules for the file.
        :param compile_flags:       The compile flags for the file.
        :param dump_includes:       Turn on diagnostics for include files.
        :param dump_privates:       Turn on diagnostics for omitted private items.
        """
        self.rules = project_rules
        self.compile_flags = compile_flags
        self.verbose = verbose
        self.dump_includes = dump_includes
        self.dump_privates = dump_privates
        self.diagnostics = set()
        self.tu = None
        self.unpreprocessed_source = None

    @staticmethod
    def describe(cursor, text=None):
        if not text:
            text = cursor.spelling
        return "{} on line {} '{}'".format(cursor.kind.name, cursor.extent.start.line, text)

    def create_sip(self, h_file, include_filename):
        """
        Actually convert the given source header file into its SIP equivalent.

        :param h_file:              The source (header) file of interest.
        :param include_filename:    The (header) to generate in the sip file.
        """

        #
        # Read in the original file.
        #
        source = h_file
        self.unpreprocessed_source = []
        with open(source, "rU") as f:
            for line in f:
                self.unpreprocessed_source.append(line)

        index = cindex.Index.create()
        self.tu = index.parse(source, ["-x", "c++"] + self.compile_flags)
        for diag in self.tu.diagnostics:
            #
            # We expect to be run over hundreds of files. Any parsing issues are likely to be very repetitive.
            # So, to avoid bothering the user, we suppress duplicates.
            #
            loc = diag.location
            msg = "{}:{}[{}] {}".format(loc.file, loc.line, loc.column, diag.spelling)
            if (diag.spelling == "#pragma once in main file"):
                continue
            if msg in self.diagnostics:
                continue
            self.diagnostics.add(msg)
            logger.log(clang_diagnostic_to_logging_diagnostic(diag.severity),
                "Parse {}: {}".format(diagnostic_word(diag.severity), msg))
        if self.dump_includes:
            for include in sorted(set(self.tu.get_includes())):
                logger.debug(_("Used includes {}").format(include.include.name))
        #
        # Run through the top level children in the translation unit.
        #
        body = self._container_get(self.tu.cursor, -1, h_file, include_filename)
        return body, self.tu.get_includes

    def skippable_attribute(self, parent, member, text, sip):
        """
        We don't seem to have access to the __attribute__(())s, but at least we can look for stuff we care about.

        :param member:          The attribute.
        :param text:            The raw source corresponding to the region of member.
        """
        if member.kind != CursorKind.VISIBILITY_ATTR:
            return False
        if member.spelling == "hidden":
            if self.dump_privates:
                logger.debug("Ignoring private {}".format(SipGenerator.describe(parent)))
            sip["name"] = ""
            return True
        return False

    def _container_get(self, container, level, h_file, include_filename):
        """
        Generate the (recursive) translation for a class or namespace.

        :param container:           A class or namespace.
        :param h_file:              Name of header file being processed.
        :param level:               Recursion level controls indentation.
        :return:                    A string.
        """

        if container.kind.is_translation_unit():
            #
            # Any module-related manual code (%ExportedHeaderCode, %ModuleCode, %ModuleHeaderCode or other
            # module-level directives?
            #
            sip = {
                "name": include_filename,
                "decl": ""
            }
            self.rules.modulecode(include_filename, sip)
            body = sip["code"]
        else:
            body = ""

        sip = {
            "name": container.displayname,
            "annotations": set()
        }
        name = container.displayname
        if container.access_specifier == AccessSpecifier.PRIVATE:
            if self.dump_privates:
                logger.debug("Ignoring private {}".format(SipGenerator.describe(container)))
            return ""
        base_specifiers = []
        template_type_parameters = []
        had_copy_constructor = False
        had_const_member = False
        for member in container.get_children():
            #
            # Only emit items in the translation unit.
            #
            if member.location.file.name != self.tu.spelling:
                continue
            decl = ""
            if member.kind in [CursorKind.CXX_METHOD, CursorKind.FUNCTION_DECL, CursorKind.FUNCTION_TEMPLATE,
                               CursorKind.CONSTRUCTOR, CursorKind.DESTRUCTOR, CursorKind.CONVERSION_FUNCTION]:
                decl = self._fn_get(container, member, level + 1)
            elif member.kind == CursorKind.ENUM_DECL:
                decl = self._enum_get(container, member, level + 1) + ";\n"
            elif member.kind == CursorKind.CXX_ACCESS_SPEC_DECL:
                decl = self._get_access_specifier(member, level + 1)
            elif member.kind == CursorKind.TYPEDEF_DECL:
                decl = self._typedef_get(container, member, level + 1)
            elif member.kind == CursorKind.CXX_BASE_SPECIFIER:
                #
                # Strip off the leading "class". Except for TypeKind.UNEXPOSED...
                #
                base_specifiers.append(member.displayname.split(None, 2)[-1])
            elif member.kind == CursorKind.TEMPLATE_TYPE_PARAMETER:
                template_type_parameters.append(member.displayname)
            elif member.kind == CursorKind.TEMPLATE_NON_TYPE_PARAMETER:
                template_type_parameters.append(member.type.spelling + " " + member.displayname)
            elif member.kind in [CursorKind.VAR_DECL, CursorKind.FIELD_DECL]:
                had_const_member = had_const_member or member.type.is_const_qualified()
                decl = self._var_get(container, member, level + 1)
            elif member.kind in [CursorKind.NAMESPACE, CursorKind.CLASS_DECL,
                                 CursorKind.CLASS_TEMPLATE, CursorKind.CLASS_TEMPLATE_PARTIAL_SPECIALIZATION,
                                 CursorKind.STRUCT_DECL, CursorKind.UNION_DECL]:
                decl = self._container_get(member, level + 1, h_file, include_filename)
            elif member.kind in TEMPLATE_KINDS + [CursorKind.USING_DECLARATION, CursorKind.USING_DIRECTIVE,
                                                  CursorKind.CXX_FINAL_ATTR]:
                #
                # Ignore:
                #
                #   TEMPLATE_KINDS: Template type parameter.
                #   CursorKind.USING_DECLARATION, CursorKind.USING_DIRECTIVE: Using? Pah!
                #   CursorKind.CXX_FINAL_ATTR: Again, not much to be done with this.
                #
                pass
            else:
                text = self._read_source(member.extent)
                if self.skippable_attribute(container, member, text, sip):
                    if not sip["name"]:
                        return ""
                else:
                    SipGenerator._report_ignoring(container, member)

            def is_copy_constructor(member):
                if member.kind != CursorKind.CONSTRUCTOR:
                    return False
                numParams = 0
                hasSelfType = False
                for child in member.get_children():
                    numParams += 1
                    if child.kind == CursorKind.PARM_DECL:
                        paramType = child.type.spelling
                        paramType = paramType.split("::")[-1]
                        paramType = paramType.replace("const", "").replace("&", "").strip()
                        hasSelfType = paramType == container.displayname
                return numParams == 1 and hasSelfType

            def has_parameter_default(parameter):
                for member in parameter.get_children():
                    if member.kind.is_expression():
                        return True
                return False

            def is_default_constructor(member):
                if member.kind != CursorKind.CONSTRUCTOR:
                    return False
                numParams = 0
                for parameter in member.get_children():
                    if (has_parameter_default(parameter)):
                        break
                    numParams += 1
                return numParams == 0

            had_copy_constructor = had_copy_constructor or is_copy_constructor(member)
            #
            # Discard almost anything which is private.
            #
            if member.access_specifier == AccessSpecifier.PRIVATE:
                if member.kind == CursorKind.CXX_ACCESS_SPEC_DECL:
                    #
                    # We need these because...
                    #
                    pass
                elif is_copy_constructor(member) or is_default_constructor(member):
                    #
                    # ...we need to pass private copy contructors to the SIP compiler.
                    #
                    pass
                else:
                    if self.dump_privates:
                        logger.debug("Ignoring private {}".format(SipGenerator.describe(member)))
                    continue

            if decl:
                if self.verbose:
                    pad = " " * ((level + 1) * 4)
                    body += pad + "// {}\n".format(SipGenerator.describe(member))
                body += decl


        if container.kind == CursorKind.TRANSLATION_UNIT:
            return body

        if container.kind == CursorKind.NAMESPACE:
            container_type = "namespace " + name
        elif container.kind in [CursorKind.CLASS_DECL, CursorKind.CLASS_TEMPLATE,
                                CursorKind.CLASS_TEMPLATE_PARTIAL_SPECIALIZATION]:
            container_type = "class " + name
        elif container.kind == CursorKind.STRUCT_DECL:
            container_type = "struct " + name
        elif container.kind == CursorKind.UNION_DECL:
            container_type = "union " + name
        else:
            raise AssertionError(
                _("Unexpected container {}: {}[{}]").format(container.kind, name, container.extent.start.line))

        sip["decl"] = container_type
        sip["template_parameters"] = template_type_parameters

        pad = " " * (level * 4)

        #
        # Empty containers are still useful if they provide namespaces or forward declarations.
        #
        if not body:
            text = self._read_source(container.extent)
            if not text.endswith("}"):
                #
                # Forward declaration.
                #
                modifying_rule = self.rules.forward_declaration_rules().apply(container, sip)
                if sip["name"]:
                    if modifying_rule:
                        body += "// Modified {} (by {}):\n".format(SipGenerator.describe(container), modifying_rule)
                    if "External" in sip["annotations"]:
                        body += pad + sip["decl"]
                        body += " /External/;\n"
                    else:
                        body = pad + "// Discarded {} (by {})\n".format(SipGenerator.describe(container), "default forward declaration handling")

                else:
                    body = pad + "// Discarded {} (by {})\n".format(SipGenerator.describe(container), modifying_rule)
        else:
            #
            # Generate private copy constructor for non-copyable types.
            #
            if had_const_member and not had_copy_constructor:
                body += "    private:\n        {}(const {} &); // Generated\n".format(name, container.type.get_canonical().spelling)
            #
            # Flesh out the SIP context for the rules engine.
            #
            sip["base_specifiers"] = base_specifiers
            sip["body"] = body
            modifying_rule = self.rules.container_rules().apply(container, sip)
            if sip["name"]:
                decl = ""
                if modifying_rule:
                    decl += "// Modified {} (by {}):\n".format(SipGenerator.describe(container), modifying_rule)
                decl += pad + sip["decl"]

                if sip["base_specifiers"]:
                    decl += ": " + ", ".join(sip["base_specifiers"])
                if sip["annotations"]:
                    decl += " /" + ",".join(sip["annotations"]) + "/"
                if sip["template_parameters"]:
                    decl = pad + "template <" + ", ".join(sip["template_parameters"]) + ">\n" + decl
                decl += "\n" + pad + "{\n"
                decl += "%TypeHeaderCode\n#include <{}>\n%End\n".format(include_filename)
                body = decl + sip["body"] + pad + "};\n"
            else:
                body = pad + "// Discarded {} (by {})\n".format(SipGenerator.describe(container), modifying_rule)
        return body

    def _get_access_specifier(self, member, level):
        """
        Skip access specifiers embedded in the Q_OBJECT macro.
        """
        access_specifier_text = self._read_source(member.extent)
        if access_specifier_text == "Q_OBJECT":
            return ""
        pad = " " * ((level - 1) * 4)
        access_specifier = ""
        if (access_specifier_text in ("Q_SIGNALS:", "signals:",
                                      "public Q_SLOTS:", "public slots:",
                                      "protected Q_SLOTS:", "protected slots:")):
            access_specifier = access_specifier_text
        elif member.access_specifier == AccessSpecifier.PRIVATE:
            access_specifier = "private:"
        elif member.access_specifier == AccessSpecifier.PROTECTED:
            access_specifier = "protected:"
        elif member.access_specifier == AccessSpecifier.PUBLIC:
            access_specifier = "public:"

        decl = pad + access_specifier + "\n"
        return decl

    def _enum_get(self, container, enum, level):
        pad = " " * (level * 4)
        decl = pad + "enum {} {{\n".format(enum.displayname)
        enumerations = []
        for enum in enum.get_children():
            #
            # Skip visibility attributes and the like.
            #
            if enum.kind == CursorKind.ENUM_CONSTANT_DECL:
                enumerations.append(pad + "    {}".format(enum.displayname))
        decl += ",\n".join(enumerations) + "\n"
        decl += pad + "}"
        return decl

    def _fn_get(self, container, function, level):
        """
        Generate the translation for a function.

        :param container:           A class or namespace.
        :param function:            The function object.
        :param level:               Recursion level controls indentation.
        :return:                    A string.
        """
        if container.kind == CursorKind.TRANSLATION_UNIT and \
                (function.semantic_parent.kind == CursorKind.CLASS_DECL or
                 function.semantic_parent.kind == CursorKind.STRUCT_DECL) and \
                function.is_definition():
            # Skip inline methods
            return

        sip = {
            "name": function.spelling,
        }
        parameters = []
        parameter_modifying_rules = []
        template_parameters = []
        for child in function.get_children():
            if child.kind == CursorKind.PARM_DECL:
                parameter = child.displayname or "__{}".format(len(parameters))
                theType = child.type.get_canonical()
                typeSpelling = theType.spelling
                if theType.kind == TypeKind.POINTER:
                    typeSpelling = theType.get_pointee().spelling + "* "

                decl = "{} {}".format(typeSpelling, parameter)
                child_sip = {
                    "name": parameter,
                    "decl": decl,
                    "init": self._fn_get_parameter_default(function, child),
                    "annotations": set()
                }
                modifying_rule = self.rules.parameter_rules().apply(container, function, child, child_sip)
                if modifying_rule:
                    parameter_modifying_rules.append("// Modified {} (by {}):\n".format(SipGenerator.describe(child), modifying_rule))
                decl = child_sip["decl"]
                if child_sip["annotations"]:
                    decl += " /" + ",".join(child_sip["annotations"]) + "/"
                if child_sip["init"]:
                    decl += " = " + child_sip["init"]
                parameters.append(decl)
            elif child.kind in [CursorKind.COMPOUND_STMT, CursorKind.CXX_OVERRIDE_ATTR,
                                CursorKind.MEMBER_REF, CursorKind.DECL_REF_EXPR, CursorKind.CALL_EXPR] + TEMPLATE_KINDS:
                #
                # Ignore:
                #
                #   CursorKind.COMPOUND_STMT: Function body.
                #   CursorKind.CXX_OVERRIDE_ATTR: The "override" keyword.
                #   CursorKind.MEMBER_REF, CursorKind.DECL_REF_EXPR, CursorKind.CALL_EXPR: Constructor initialisers.
                #   TEMPLATE_KINDS: The result type.
                #
                pass
            elif child.kind == CursorKind.TEMPLATE_TYPE_PARAMETER:
                template_parameters.append(child.displayname)
            elif child.kind == CursorKind.TEMPLATE_NON_TYPE_PARAMETER:
                template_parameters.append(child.type.spelling + " " + child.displayname)
            else:
                text = self._read_source(child.extent)
                if self.skippable_attribute(function, child, text, sip):
                    if not sip["name"]:
                        return ""
                else:
                    SipGenerator._report_ignoring(function, child)
        #
        # Flesh out the SIP context for the rules engine.
        #
        sip["template_parameters"] = template_parameters
        if function.kind in [CursorKind.CONSTRUCTOR, CursorKind.DESTRUCTOR]:
            sip["fn_result"] = ""
        else:
            sip["fn_result"] = function.result_type.spelling
        sip["parameters"] = parameters
        sip["prefix"], sip["suffix"] = self._fn_get_decorators(function)
        modifying_rule = self.rules.function_rules().apply(container, function, sip)
        pad = " " * (level * 4)
        if sip["name"]:
            #
            # Any method-related code (%MethodCode, %VirtualCatcherCode, VirtualCallCode
            # or other method-related directives)?
            #
            self.rules.methodcode(function, sip)
            decl = ""
            if modifying_rule:
                decl += "// Modified {} (by {}):\n".format(SipGenerator.describe(function), modifying_rule) + pad
            decl += pad.join(parameter_modifying_rules)
            if parameter_modifying_rules:
                decl += pad

            decl += sip["name"] + "(" + ", ".join(sip["parameters"]) + ")"
            if sip["fn_result"]:
                decl = sip["fn_result"] + " " + decl
            decl = pad + sip["prefix"] + decl + sip["suffix"]
            if sip["template_parameters"]:
                decl = pad + "template <" + ", ".join(sip["template_parameters"]) + ">\n" + decl
            decl += ";\n"
            decl += sip["code"]
        else:
            decl = pad + "// Discarded {} (by {})\n".format(SipGenerator.describe(function), modifying_rule)
        return decl

    def _fn_get_decorators(self, function):
        """
        The parser does not provide direct access to the complete keywords (explicit, const, static, etc) of a function
        in the displayname. It would be nice to get these from the AST, but I cannot find where they are hiding.

        Now, we could resort to using the original source. That does not bode well if you have macros (QOBJECT,
        xxxDEPRECATED?), inlined bodies and the like, using the rule engine could be used to patch corner cases...

        ...or we can try to guess what SIP cares about, i.e static and maybe const. Luckily (?), we have those to hand!

        :param function:                    The function object.
        :return: prefix, suffix             String containing any prefix or suffix keywords.
        """
        suffix = ""
        if function.is_const_method():
            suffix += " const"
        prefix = ""
        if function.is_static_method():
            prefix += "static "
        if function.is_virtual_method():
            prefix += "virtual "
            if function.is_pure_virtual_method():
                suffix += " = 0"
        return prefix, suffix

    def _fn_get_parameter_default(self, function, parameter):
        """
        The parser does not seem to provide access to the complete text of a parameter.
        This makes it hard to find any default values, so we:

            1. Run the lexer from "here" to the end of the file, bailing out when we see the ","
            or a ")" marking the end.
            2. Watch for the assignment.
        """
        def _get_param_type(parameter):
            result = parameter.type.get_declaration().type

            if result.kind != TypeKind.ENUM and result.kind != TypeKind.TYPEDEF and parameter.type.kind == TypeKind.LVALUEREFERENCE:
                if parameter.type.get_pointee().get_declaration().type.kind != TypeKind.INVALID:
                    return parameter.type.get_pointee().get_declaration().type
                return parameter.type.get_pointee()

            if parameter.type.get_declaration().type.kind == TypeKind.INVALID:
                return parameter.type

            if (parameter.type.get_declaration().type.kind == TypeKind.TYPEDEF):
                isQFlags = False
                for member in parameter.type.get_declaration().get_children():
                    if member.kind == CursorKind.TEMPLATE_REF and member.spelling == "QFlags":
                        isQFlags = True
                    if isQFlags and member.kind == CursorKind.TYPE_REF:
                        result = member.type
                        break

            return result

        def _get_param_value(text, parameterType):
            if text == "0" or text == "nullptr":
                return text
            if text == "{}":
                if parameterType.kind == TypeKind.ENUM:
                    return "0"
                if parameterType.kind == TypeKind.POINTER:
                    return "nullptr"
                if parameterType.spelling.startswith("const "):
                    return parameterType.spelling[6:] + "()"
                return parameterType.spelling + "()"
            if not "::" in parameterType.spelling:
                return text
            try:
                typeText, typeInit = text.split("(")
                typeInit = "(" + typeInit
            except:
                typeText = text
                typeInit = ""

            prefix = parameterType.spelling.rsplit("::", 1)[0]
            if "::" in typeText:
                typeText = typeText.rsplit("::", 1)[1]
            return prefix + "::" + typeText + typeInit


        for member in parameter.get_children():
            if member.kind.is_expression():

                possible_extent = SourceRange.from_locations(parameter.extent.start, function.extent.end)
                text = ""
                bracket_level = 0
                found_start = False
                found_end = False
                for token in self.tu.get_tokens(extent=possible_extent):
                    if (token.spelling == "="):
                        found_start = True
                        continue
                    if token.spelling == "," and bracket_level == 0:
                        found_end = True
                        break
                    elif token.spelling == "(":
                        bracket_level += 1
                        text += token.spelling
                    elif token.spelling == ")":
                        if bracket_level == 0:
                            found_end = True
                            break
                        bracket_level -= 1
                        text += token.spelling
                        if bracket_level == 0:
                            found_end = True
                            break
                    elif found_start:
                        text += token.spelling
                if not found_end and text:
                    RuntimeError(_("No end found for {}::{}, '{}'").format(function.spelling, parameter.spelling, text))

                parameterType = _get_param_type(parameter)

                return _get_param_value(text, parameterType)
        return ""

    def _typedef_get(self, container, typedef, level):
        """
        Generate the translation for a typedef.

        :param container:           A class or namespace.
        :param typedef:             The typedef object.
        :param level:               Recursion level controls indentation.
        :return:                    A string.
        """

        sip = {
            "name": typedef.displayname,
            "decl": typedef.underlying_typedef_type.spelling,
            "annotations": set(),
        }

        self.rules.typedef_rules().apply(container, typedef, sip)

        pad = " " * (level * 4)
        if sip["name"]:
            decl = pad + "typedef {} {}".format(sip["decl"], sip["name"])
            decl += ";\n"
        else:
            decl = pad + "// Discarded {}\n".format(SipGenerator.describe(typedef))
        return decl

    def _var_get(self, container, variable, level):
        """
        Generate the translation for a variable.

        :param container:           A class or namespace.
        :param variable:            The variable object.
        :param level:               Recursion level controls indentation.
        :return:                    A string.
        """

        sip = {
            "name": variable.spelling
        }
        for child in variable.get_children():
            if child.kind in TEMPLATE_KINDS + [CursorKind.STRUCT_DECL, CursorKind.UNION_DECL]:
                #
                # Ignore:
                #
                #   TEMPLATE_KINDS, CursorKind.STRUCT_DECL, CursorKind.UNION_DECL: : The variable type.
                #
                pass
            else:
                text = self._read_source(child.extent)
                if self.skippable_attribute(variable, child, text, sip):
                    if not sip["name"]:
                        return ""
                else:
                    SipGenerator._report_ignoring(variable, child)
        #
        # Flesh out the SIP context for the rules engine.
        #
        decl = "{} {}".format(variable.type.spelling, variable.spelling)
        sip["decl"] = decl
        modifying_rule = self.rules.variable_rules().apply(container, variable, sip)

        pad = " " * (level * 4)
        if sip["name"]:
            decl = sip["decl"]
            #
            # SIP does not support protected variables, so we ignore them.
            #
            if variable.access_specifier == AccessSpecifier.PROTECTED:
                decl = pad + "// Discarded {}\n".format(SipGenerator.describe(variable))
            else:
                decl = pad + decl + ";\n"
        else:
            decl = pad + "// Discarded {} (by {})\n".format(SipGenerator.describe(variable), modifying_rule)
        return decl

    def _read_source(self, extent):
        """
        Read the given range from the unpre-processed source.

        :param extent:              The range of text required.
        """
        extract = self.unpreprocessed_source[extent.start.line - 1:extent.end.line]
        if extent.start.line == extent.end.line:
            extract[0] = extract[0][extent.start.column - 1:extent.end.column - 1]
        else:
            extract[0] = extract[0][extent.start.column - 1:]
            extract[-1] = extract[-1][:extent.end.column - 1]
        #
        # Return a single line of text.
        #
        return "".join(extract).replace("\n", " ")

    @staticmethod
    def _report_ignoring(parent, child, text=None):
        if not text:
            text = child.displayname or child.spelling
        logger.debug(_("Ignoring {} {} child {}").format(parent.kind.name, parent.spelling, SipGenerator.describe(child, text)))


def main(argv=None):
    """
    Take a single C++ header file and generate the corresponding SIP file.
    Beyond simple generation of the SIP file from the corresponding C++
    header file, a set of rules can be used to customise the generated
    SIP file.

    Examples:

        sip_generator.py /usr/include/KF5/KItemModels/kselectionproxymodel.h
    """
    if argv is None:
        argv = sys.argv
    parser = argparse.ArgumentParser(epilog=inspect.getdoc(main),
                                     formatter_class=HelpFormatter)
    parser.add_argument("-v", "--verbose", action="store_true", default=False, help=_("Enable verbose output"))
    parser.add_argument("--flags",
                        help=_("Semicolon-separated C++ compile flags to use"))
    parser.add_argument("--include_filename", help=_("C++ header include to compile"))
    parser.add_argument("libclang", help=_("libclang library to use for parsing"))
    parser.add_argument("project_rules", help=_("Project rules"))
    parser.add_argument("source", help=_("C++ header to process"))
    parser.add_argument("output", help=_("output filename to write"))
    try:
        args = parser.parse_args(argv[1:])
        if args.verbose:
            logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(name)s %(levelname)s: %(message)s')
        else:
            logging.basicConfig(level=logging.INFO, format='%(levelname)s: %(message)s')
        #
        # Generate!
        #

        cindex.Config.set_library_file(args.libclang)

        rules = rules_engine.rules(args.project_rules)
        g = SipGenerator(rules, args.flags.lstrip().split(";"), args.verbose)
        body, includes = g.create_sip(args.source, args.include_filename)
        with open(args.output, "w") as outputFile:
            outputFile.write(body)
    except Exception as e:
        tbk = traceback.format_exc()
        print(tbk)
        return -1


if __name__ == "__main__":
    if sys.argv[1] != "--self-check":
        sys.exit(main())
    else:
        cindex.Config.set_library_file(sys.argv[2])
