Add the rules_engine and sip_generator

These files process C++ headers with libclang and python-clang bindings,
using the AST to generate SIP files for PyQt binding library generation.

The design allows for further extensions which can process other
artifacts found in headers.  This iteration of the design is a simple
minimum which suffices to generate headers for KItemModels and some
other libraries.

1 files changed, 700 insertions, 0 deletions

diff --git a/find-modules/sip_generator.py b/find-modules/sip_generator.py
new file mode 100644
index 00000000..10be1477
--- /dev/null
+++ b/find-modules/sip_generator.py
@@ -0,0 +1,700 @@
+#!/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 subprocess
+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
+
+
+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 msg in self.diagnostics:
+                continue
+            self.diagnostics.add(msg)
+            logger.log(diag.severity, "Parse error {}".format(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
+
+    CONTAINER_SKIPPABLE_UNEXPOSED_DECL = re.compile("_DECLARE_PRIVATE|friend|;")
+    FN_SKIPPABLE_ATTR = re.compile("_EXPORT|Q_REQUIRED_RESULT|format\(printf")
+    VAR_SKIPPABLE_ATTR = re.compile("_EXPORT")
+    TYPEDEF_SKIPPABLE_ATTR = re.compile("_EXPORT")
+
+    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.
+        """
+
+        def skippable_attribute(member, text):
+            """
+            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 text.find("_DEPRECATED") != -1:
+                sip["annotations"].add("Deprecated")
+                return True
+            SipGenerator._report_ignoring(container, member, text)
+
+        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 ""
+        body = ""
+        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(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:
+                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
+        #
+        # Empty containers are still useful if they provide namespaces or forward declarations.
+        #
+        if not body and level >= 0:
+            body = "\n"
+            text = self._read_source(container.extent)
+            if not text.endswith("}"):
+                #
+                # Forward declaration.
+                #
+                sip["annotations"].add("External")
+        if body and level >= 0:
+            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))
+            #
+            # 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["template_parameters"] = ", ".join(template_type_parameters)
+            sip["decl"] = container_type
+            sip["base_specifiers"] = ", ".join(base_specifiers)
+            sip["body"] = body
+            self.rules.container_rules().apply(container, sip)
+            pad = " " * (level * 4)
+            if sip["name"]:
+                decl = pad + sip["decl"]
+                if "External" in sip["annotations"]:
+                    #
+                    # SIP /External/ does not seem to work as one might wish. Suppress.
+                    #
+                    body = decl + " /External/;\n"
+                    body = pad + "// Discarded {}\n".format(SipGenerator.describe(container))
+                else:
+                    if sip["base_specifiers"]:
+                        decl += ": " + sip["base_specifiers"]
+                    if sip["annotations"]:
+                        decl += " /" + ",".join(sip["annotations"]) + "/"
+                    if sip["template_parameters"]:
+                        decl = pad + "template <" + 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 {}\n".format(SipGenerator.describe(container))
+        return body
+
+    def _get_access_specifier(self, member, level):
+        """
+        Skip access specifiers embedded in the Q_OBJECT macro.
+        """
+        access_specifier = self._read_source(member.extent)
+        if access_specifier == "Q_OBJECT":
+            return ""
+        pad = " " * ((level - 1) * 4)
+        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():
+            enumerations.append(pad + "    {}".format(enum.displayname))
+            assert enum.kind == CursorKind.ENUM_CONSTANT_DECL
+        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.
+        """
+
+        def skippable_attribute(member, text):
+            """
+            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 SipGenerator.FN_SKIPPABLE_ATTR.search(text):
+                return True
+            SipGenerator._report_ignoring(function, member, text)
+
+        sip = {
+            "name": function.spelling,
+        }
+        parameters = []
+        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()
+                }
+                self.rules.parameter_rules().apply(container, function, child, child_sip)
+                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 child.kind in [CursorKind.UNEXPOSED_ATTR, CursorKind.VISIBILITY_ATTR] and skippable_attribute(child,
+                                                                                                                 text):
+                    pass
+                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)
+        self.rules.function_rules().apply(container, function, sip)
+        pad = " " * (level * 4)
+        if sip["name"]:
+            sip["template_parameters"] = ", ".join(sip["template_parameters"])
+            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 <" + sip["template_parameters"] + ">\n" + decl
+            decl += ";\n"
+        else:
+            decl = pad + "// Discarded {}\n".format(SipGenerator.describe(function))
+        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 (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":
+                return text
+            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, 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.
+        """
+
+        pad = " " * (level * 4)
+
+        decl = pad + "typedef {} {}".format(typedef.underlying_typedef_type.spelling, typedef.displayname)
+        decl += ";\n"
+        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.
+        """
+
+        def skippable_attribute(member, text):
+            """
+            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 SipGenerator.VAR_SKIPPABLE_ATTR.search(text):
+                return True
+            SipGenerator._report_ignoring(container, member, text)
+
+        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 child.kind == CursorKind.VISIBILITY_ATTR and skippable_attribute(child, text):
+                    pass
+                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
+        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 {}\n".format(SipGenerator.describe(variable))
+        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])