xref: /external/clang/bindings/python/clang/cindex.py

#===- cindex.py - Python Indexing Library Bindings -----------*- python -*--===#
#
#                     The LLVM Compiler Infrastructure
#
# This file is distributed under the University of Illinois Open Source
# License. See LICENSE.TXT for details.
#
#===------------------------------------------------------------------------===#

r"""
Clang Indexing Library Bindings
===============================

This module provides an interface to the Clang indexing library. It is a
low-level interface to the indexing library which attempts to match the Clang
API directly while also being "pythonic". Notable differences from the C API
are:

 * string results are returned as Python strings, not CXString objects.

 * null cursors are translated to None.

 * access to child cursors is done via iteration, not visitation.

The major indexing objects are:

  Index

    The top-level object which manages some global library state.

  TranslationUnit

    High-level object encapsulating the AST for a single translation unit. These
    can be loaded from .ast files or parsed on the fly.

  Cursor

    Generic object for representing a node in the AST.

  SourceRange, SourceLocation, and File

    Objects representing information about the input source.

Most object information is exposed using properties, when the underlying API
call is efficient.
"""

# TODO
# ====
#
# o API support for invalid translation units. Currently we can't even get the
#   diagnostics on failure because they refer to locations in an object that
#   will have been invalidated.
#
# o fix memory management issues (currently client must hold on to index and
#   translation unit, or risk crashes).
#
# o expose code completion APIs.
#
# o cleanup ctypes wrapping, would be nice to separate the ctypes details more
#   clearly, and hide from the external interface (i.e., help(cindex)).
#
# o implement additional SourceLocation, SourceRange, and File methods.

from ctypes import *
import collections

import clang.enumerations

# ctypes doesn't implicitly convert c_void_p to the appropriate wrapper
# object. This is a problem, because it means that from_parameter will see an
# integer and pass the wrong value on platforms where int != void*. Work around
# this by marshalling object arguments as void**.
c_object_p = POINTER(c_void_p)

callbacks = {}

### Exception Classes ###

class TranslationUnitLoadError(Exception):
    """Represents an error that occurred when loading a TranslationUnit.

    This is raised in the case where a TranslationUnit could not be
    instantiated due to failure in the libclang library.

    FIXME: Make libclang expose additional error information in this scenario.
    """
    pass

class TranslationUnitSaveError(Exception):
    """Represents an error that occurred when saving a TranslationUnit.

    Each error has associated with it an enumerated value, accessible under
    e.save_error. Consumers can compare the value with one of the ERROR_
    constants in this class.
    """

    # Indicates that an unknown error occurred. This typically indicates that
    # I/O failed during save.
    ERROR_UNKNOWN = 1

    # Indicates that errors during translation prevented saving. The errors
    # should be available via the TranslationUnit's diagnostics.
    ERROR_TRANSLATION_ERRORS = 2

    # Indicates that the translation unit was somehow invalid.
    ERROR_INVALID_TU = 3

    def __init__(self, enumeration, message):
        assert isinstance(enumeration, int)

        if enumeration < 1 or enumeration > 3:
            raise Exception("Encountered undefined TranslationUnit save error "
                            "constant: %d. Please file a bug to have this "
                            "value supported." % enumeration)

        self.save_error = enumeration
        Exception.__init__(self, 'Error %d: %s' % (enumeration, message))

### Structures and Utility Classes ###

class CachedProperty(object):
    """Decorator that lazy-loads the value of a property.

    The first time the property is accessed, the original property function is
    executed. The value it returns is set as the new value of that instance's
    property, replacing the original method.
    """

    def __init__(self, wrapped):
        self.wrapped = wrapped
        try:
            self.__doc__ = wrapped.__doc__
        except:
            pass

    def __get__(self, instance, instance_type=None):
        if instance is None:
            return self

        value = self.wrapped(instance)
        setattr(instance, self.wrapped.__name__, value)

        return value


class _CXString(Structure):
    """Helper for transforming CXString results."""

    _fields_ = [("spelling", c_char_p), ("free", c_int)]

    def __del__(self):
        conf.lib.clang_disposeString(self)

    @staticmethod
    def from_result(res, fn, args):
        assert isinstance(res, _CXString)
        return conf.lib.clang_getCString(res)

class SourceLocation(Structure):
    """
    A SourceLocation represents a particular location within a source file.
    """
    _fields_ = [("ptr_data", c_void_p * 2), ("int_data", c_uint)]
    _data = None

    def _get_instantiation(self):
        if self._data is None:
            f, l, c, o = c_object_p(), c_uint(), c_uint(), c_uint()
            conf.lib.clang_getInstantiationLocation(self, byref(f), byref(l),
                    byref(c), byref(o))
            if f:
                f = File(f)
            else:
                f = None
            self._data = (f, int(l.value), int(c.value), int(o.value))
        return self._data

    @staticmethod
    def from_position(tu, file, line, column):
        """
        Retrieve the source location associated with a given file/line/column in
        a particular translation unit.
        """
        return conf.lib.clang_getLocation(tu, file, line, column)

    @staticmethod
    def from_offset(tu, file, offset):
        """Retrieve a SourceLocation from a given character offset.

        tu -- TranslationUnit file belongs to
        file -- File instance to obtain offset from
        offset -- Integer character offset within file
        """
        return conf.lib.clang_getLocationForOffset(tu, file, offset)

    @property
    def file(self):
        """Get the file represented by this source location."""
        return self._get_instantiation()[0]

    @property
    def line(self):
        """Get the line represented by this source location."""
        return self._get_instantiation()[1]

    @property
    def column(self):
        """Get the column represented by this source location."""
        return self._get_instantiation()[2]

    @property
    def offset(self):
        """Get the file offset represented by this source location."""
        return self._get_instantiation()[3]

    def __eq__(self, other):
        return conf.lib.clang_equalLocations(self, other)

    def __ne__(self, other):
        return not self.__eq__(other)

    def __repr__(self):
        if self.file:
            filename = self.file.name
        else:
            filename = None
        return "<SourceLocation file %r, line %r, column %r>" % (
            filename, self.line, self.column)

class SourceRange(Structure):
    """
    A SourceRange describes a range of source locations within the source
    code.
    """
    _fields_ = [
        ("ptr_data", c_void_p * 2),
        ("begin_int_data", c_uint),
        ("end_int_data", c_uint)]

    # FIXME: Eliminate this and make normal constructor? Requires hiding ctypes
    # object.
    @staticmethod
    def from_locations(start, end):
        return conf.lib.clang_getRange(start, end)

    @property
    def start(self):
        """
        Return a SourceLocation representing the first character within a
        source range.
        """
        return conf.lib.clang_getRangeStart(self)

    @property
    def end(self):
        """
        Return a SourceLocation representing the last character within a
        source range.
        """
        return conf.lib.clang_getRangeEnd(self)

    def __eq__(self, other):
        return conf.lib.clang_equalRanges(self, other)

    def __ne__(self, other):
        return not self.__eq__(other)

    def __repr__(self):
        return "<SourceRange start %r, end %r>" % (self.start, self.end)

class Diagnostic(object):
    """
    A Diagnostic is a single instance of a Clang diagnostic. It includes the
    diagnostic severity, the message, the location the diagnostic occurred, as
    well as additional source ranges and associated fix-it hints.
    """

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

    def __init__(self, ptr):
        self.ptr = ptr

    def __del__(self):
        conf.lib.clang_disposeDiagnostic(self)

    @property
    def severity(self):
        return conf.lib.clang_getDiagnosticSeverity(self)

    @property
    def location(self):
        return conf.lib.clang_getDiagnosticLocation(self)

    @property
    def spelling(self):
        return conf.lib.clang_getDiagnosticSpelling(self)

    @property
    def ranges(self):
        class RangeIterator:
            def __init__(self, diag):
                self.diag = diag

            def __len__(self):
                return int(conf.lib.clang_getDiagnosticNumRanges(self.diag))

            def __getitem__(self, key):
                if (key >= len(self)):
                    raise IndexError
                return conf.lib.clang_getDiagnosticRange(self.diag, key)

        return RangeIterator(self)

    @property
    def fixits(self):
        class FixItIterator:
            def __init__(self, diag):
                self.diag = diag

            def __len__(self):
                return int(conf.lib.clang_getDiagnosticNumFixIts(self.diag))

            def __getitem__(self, key):
                range = SourceRange()
                value = conf.lib.clang_getDiagnosticFixIt(self.diag, key,
                        byref(range))
                if len(value) == 0:
                    raise IndexError

                return FixIt(range, value)

        return FixItIterator(self)

    @property
    def category_number(self):
        """The category number for this diagnostic."""
        return conf.lib.clang_getDiagnosticCategory(self)

    @property
    def category_name(self):
        """The string name of the category for this diagnostic."""
        return conf.lib.clang_getDiagnosticCategoryName(self.category_number)

    @property
    def option(self):
        """The command-line option that enables this diagnostic."""
        return conf.lib.clang_getDiagnosticOption(self, None)

    @property
    def disable_option(self):
        """The command-line option that disables this diagnostic."""
        disable = _CXString()
        conf.lib.clang_getDiagnosticOption(self, byref(disable))

        return conf.lib.clang_getCString(disable)

    def __repr__(self):
        return "<Diagnostic severity %r, location %r, spelling %r>" % (
            self.severity, self.location, self.spelling)

    def from_param(self):
      return self.ptr

class FixIt(object):
    """
    A FixIt represents a transformation to be applied to the source to
    "fix-it". The fix-it shouldbe applied by replacing the given source range
    with the given value.
    """

    def __init__(self, range, value):
        self.range = range
        self.value = value

    def __repr__(self):
        return "<FixIt range %r, value %r>" % (self.range, self.value)

class TokenGroup(object):
    """Helper class to facilitate token management.

    Tokens are allocated from libclang in chunks. They must be disposed of as a
    collective group.

    One purpose of this class is for instances to represent groups of allocated
    tokens. Each token in a group contains a reference back to an instance of
    this class. When all tokens from a group are garbage collected, it allows
    this class to be garbage collected. When this class is garbage collected,
    it calls the libclang destructor which invalidates all tokens in the group.

    You should not instantiate this class outside of this module.
    """
    def __init__(self, tu, memory, count):
        self._tu = tu
        self._memory = memory
        self._count = count

    def __del__(self):
        conf.lib.clang_disposeTokens(self._tu, self._memory, self._count)

    @staticmethod
    def get_tokens(tu, extent):
        """Helper method to return all tokens in an extent.

        This functionality is needed multiple places in this module. We define
        it here because it seems like a logical place.
        """
        tokens_memory = POINTER(Token)()
        tokens_count = c_uint()

        conf.lib.clang_tokenize(tu, extent, byref(tokens_memory),
                byref(tokens_count))

        count = int(tokens_count.value)

        # If we get no tokens, no memory was allocated. Be sure not to return
        # anything and potentially call a destructor on nothing.
        if count < 1:
            return

        tokens_array = cast(tokens_memory, POINTER(Token * count)).contents

        token_group = TokenGroup(tu, tokens_memory, tokens_count)

        for i in xrange(0, count):
            token = Token()
            token.int_data = tokens_array[i].int_data
            token.ptr_data = tokens_array[i].ptr_data
            token._tu = tu
            token._group = token_group

            yield token

class TokenKind(object):
    """Describes a specific type of a Token."""

    _value_map = {} # int -> TokenKind

    def __init__(self, value, name):
        """Create a new TokenKind instance from a numeric value and a name."""
        self.value = value
        self.name = name

    def __repr__(self):
        return 'TokenKind.%s' % (self.name,)

    @staticmethod
    def from_value(value):
        """Obtain a registered TokenKind instance from its value."""
        result = TokenKind._value_map.get(value, None)

        if result is None:
            raise ValueError('Unknown TokenKind: %d' % value)

        return result

    @staticmethod
    def register(value, name):
        """Register a new TokenKind enumeration.

        This should only be called at module load time by code within this
        package.
        """
        if value in TokenKind._value_map:
            raise ValueError('TokenKind already registered: %d' % value)

        kind = TokenKind(value, name)
        TokenKind._value_map[value] = kind
        setattr(TokenKind, name, kind)

### Cursor Kinds ###

class CursorKind(object):
    """
    A CursorKind describes the kind of entity that a cursor points to.
    """

    # The unique kind objects, indexed by id.
    _kinds = []
    _name_map = None

    def __init__(self, value):
        if value >= len(CursorKind._kinds):
            CursorKind._kinds += [None] * (value - len(CursorKind._kinds) + 1)
        if CursorKind._kinds[value] is not None:
            raise ValueError,'CursorKind already loaded'
        self.value = value
        CursorKind._kinds[value] = self
        CursorKind._name_map = None

    def from_param(self):
        return self.value

    @property
    def name(self):
        """Get the enumeration name of this cursor kind."""
        if self._name_map is None:
            self._name_map = {}
            for key,value in CursorKind.__dict__.items():
                if isinstance(value,CursorKind):
                    self._name_map[value] = key
        return self._name_map[self]

    @staticmethod
    def from_id(id):
        if id >= len(CursorKind._kinds) or CursorKind._kinds[id] is None:
            raise ValueError,'Unknown cursor kind %d' % id
        return CursorKind._kinds[id]

    @staticmethod
    def get_all_kinds():
        """Return all CursorKind enumeration instances."""
        return filter(None, CursorKind._kinds)

    def is_declaration(self):
        """Test if this is a declaration kind."""
        return conf.lib.clang_isDeclaration(self)

    def is_reference(self):
        """Test if this is a reference kind."""
        return conf.lib.clang_isReference(self)

    def is_expression(self):
        """Test if this is an expression kind."""
        return conf.lib.clang_isExpression(self)

    def is_statement(self):
        """Test if this is a statement kind."""
        return conf.lib.clang_isStatement(self)

    def is_attribute(self):
        """Test if this is an attribute kind."""
        return conf.lib.clang_isAttribute(self)

    def is_invalid(self):
        """Test if this is an invalid kind."""
        return conf.lib.clang_isInvalid(self)

    def is_translation_unit(self):
        """Test if this is a translation unit kind."""
        return conf.lib.clang_isTranslationUnit(self)

    def is_preprocessing(self):
        """Test if this is a preprocessing kind."""
        return conf.lib.clang_isPreprocessing(self)

    def is_unexposed(self):
        """Test if this is an unexposed kind."""
        return conf.lib.clang_isUnexposed(self)

    def __repr__(self):
        return 'CursorKind.%s' % (self.name,)

# FIXME: Is there a nicer way to expose this enumeration? We could potentially
# represent the nested structure, or even build a class hierarchy. The main
# things we want for sure are (a) simple external access to kinds, (b) a place
# to hang a description and name, (c) easy to keep in sync with Index.h.

###
# Declaration Kinds

# A declaration whose specific kind is not exposed via this interface.
#
# Unexposed declarations have the same operations as any other kind of
# declaration; one can extract their location information, spelling, find their
# definitions, etc. However, the specific kind of the declaration is not
# reported.
CursorKind.UNEXPOSED_DECL = CursorKind(1)

# A C or C++ struct.
CursorKind.STRUCT_DECL = CursorKind(2)

# A C or C++ union.
CursorKind.UNION_DECL = CursorKind(3)

# A C++ class.
CursorKind.CLASS_DECL = CursorKind(4)

# An enumeration.
CursorKind.ENUM_DECL = CursorKind(5)

# A field (in C) or non-static data member (in C++) in a struct, union, or C++
# class.
CursorKind.FIELD_DECL = CursorKind(6)

# An enumerator constant.
CursorKind.ENUM_CONSTANT_DECL = CursorKind(7)

# A function.
CursorKind.FUNCTION_DECL = CursorKind(8)

# A variable.
CursorKind.VAR_DECL = CursorKind(9)

# A function or method parameter.
CursorKind.PARM_DECL = CursorKind(10)

# An Objective-C @interface.
CursorKind.OBJC_INTERFACE_DECL = CursorKind(11)

# An Objective-C @interface for a category.
CursorKind.OBJC_CATEGORY_DECL = CursorKind(12)

# An Objective-C @protocol declaration.
CursorKind.OBJC_PROTOCOL_DECL = CursorKind(13)

# An Objective-C @property declaration.
CursorKind.OBJC_PROPERTY_DECL = CursorKind(14)

# An Objective-C instance variable.
CursorKind.OBJC_IVAR_DECL = CursorKind(15)

# An Objective-C instance method.
CursorKind.OBJC_INSTANCE_METHOD_DECL = CursorKind(16)

# An Objective-C class method.
CursorKind.OBJC_CLASS_METHOD_DECL = CursorKind(17)

# An Objective-C @implementation.
CursorKind.OBJC_IMPLEMENTATION_DECL = CursorKind(18)

# An Objective-C @implementation for a category.
CursorKind.OBJC_CATEGORY_IMPL_DECL = CursorKind(19)

# A typedef.
CursorKind.TYPEDEF_DECL = CursorKind(20)

# A C++ class method.
CursorKind.CXX_METHOD = CursorKind(21)

# A C++ namespace.
CursorKind.NAMESPACE = CursorKind(22)

# A linkage specification, e.g. 'extern "C"'.
CursorKind.LINKAGE_SPEC = CursorKind(23)

# A C++ constructor.
CursorKind.CONSTRUCTOR = CursorKind(24)

# A C++ destructor.
CursorKind.DESTRUCTOR = CursorKind(25)

# A C++ conversion function.
CursorKind.CONVERSION_FUNCTION = CursorKind(26)

# A C++ template type parameter
CursorKind.TEMPLATE_TYPE_PARAMETER = CursorKind(27)

# A C++ non-type template paramater.
CursorKind.TEMPLATE_NON_TYPE_PARAMETER = CursorKind(28)

# A C++ template template parameter.
CursorKind.TEMPLATE_TEMPLATE_PARAMETER = CursorKind(29)

# A C++ function template.
CursorKind.FUNCTION_TEMPLATE = CursorKind(30)

# A C++ class template.
CursorKind.CLASS_TEMPLATE = CursorKind(31)

# A C++ class template partial specialization.
CursorKind.CLASS_TEMPLATE_PARTIAL_SPECIALIZATION = CursorKind(32)

# A C++ namespace alias declaration.
CursorKind.NAMESPACE_ALIAS = CursorKind(33)

# A C++ using directive
CursorKind.USING_DIRECTIVE = CursorKind(34)

# A C++ using declaration
CursorKind.USING_DECLARATION = CursorKind(35)

# A Type alias decl.
CursorKind.TYPE_ALIAS_DECL = CursorKind(36)

# A Objective-C synthesize decl
CursorKind.OBJC_SYNTHESIZE_DECL = CursorKind(37)

# A Objective-C dynamic decl
CursorKind.OBJC_DYNAMIC_DECL = CursorKind(38)

# A C++ access specifier decl.
CursorKind.CXX_ACCESS_SPEC_DECL = CursorKind(39)


###
# Reference Kinds

CursorKind.OBJC_SUPER_CLASS_REF = CursorKind(40)
CursorKind.OBJC_PROTOCOL_REF = CursorKind(41)
CursorKind.OBJC_CLASS_REF = CursorKind(42)

# A reference to a type declaration.
#
# A type reference occurs anywhere where a type is named but not
# declared. For example, given:
#   typedef unsigned size_type;
#   size_type size;
#
# The typedef is a declaration of size_type (CXCursor_TypedefDecl),
# while the type of the variable "size" is referenced. The cursor
# referenced by the type of size is the typedef for size_type.
CursorKind.TYPE_REF = CursorKind(43)
CursorKind.CXX_BASE_SPECIFIER = CursorKind(44)

# A reference to a class template, function template, template
# template parameter, or class template partial specialization.
CursorKind.TEMPLATE_REF = CursorKind(45)

# A reference to a namespace or namepsace alias.
CursorKind.NAMESPACE_REF = CursorKind(46)

# A reference to a member of a struct, union, or class that occurs in
# some non-expression context, e.g., a designated initializer.
CursorKind.MEMBER_REF = CursorKind(47)

# A reference to a labeled statement.
CursorKind.LABEL_REF = CursorKind(48)

# A reference to a set of overloaded functions or function templates
# that has not yet been resolved to a specific function or function template.
CursorKind.OVERLOADED_DECL_REF = CursorKind(49)

# A reference to a variable that occurs in some non-expression
# context, e.g., a C++ lambda capture list.
CursorKind.VARIABLE_REF = CursorKind(50)

###
# Invalid/Error Kinds

CursorKind.INVALID_FILE = CursorKind(70)
CursorKind.NO_DECL_FOUND = CursorKind(71)
CursorKind.NOT_IMPLEMENTED = CursorKind(72)
CursorKind.INVALID_CODE = CursorKind(73)

###
# Expression Kinds

# An expression whose specific kind is not exposed via this interface.
#
# Unexposed expressions have the same operations as any other kind of
# expression; one can extract their location information, spelling, children,
# etc. However, the specific kind of the expression is not reported.
CursorKind.UNEXPOSED_EXPR = CursorKind(100)

# An expression that refers to some value declaration, such as a function,
# varible, or enumerator.
CursorKind.DECL_REF_EXPR = CursorKind(101)

# An expression that refers to a member of a struct, union, class, Objective-C
# class, etc.
CursorKind.MEMBER_REF_EXPR = CursorKind(102)

# An expression that calls a function.
CursorKind.CALL_EXPR = CursorKind(103)

# An expression that sends a message to an Objective-C object or class.
CursorKind.OBJC_MESSAGE_EXPR = CursorKind(104)

# An expression that represents a block literal.
CursorKind.BLOCK_EXPR = CursorKind(105)

# An integer literal.
CursorKind.INTEGER_LITERAL = CursorKind(106)

# A floating point number literal.
CursorKind.FLOATING_LITERAL = CursorKind(107)

# An imaginary number literal.
CursorKind.IMAGINARY_LITERAL = CursorKind(108)

# A string literal.
CursorKind.STRING_LITERAL = CursorKind(109)

# A character literal.
CursorKind.CHARACTER_LITERAL = CursorKind(110)

# A parenthesized expression, e.g. "(1)".
#
# This AST node is only formed if full location information is requested.
CursorKind.PAREN_EXPR = CursorKind(111)

# This represents the unary-expression's (except sizeof and
# alignof).
CursorKind.UNARY_OPERATOR = CursorKind(112)

# [C99 6.5.2.1] Array Subscripting.
CursorKind.ARRAY_SUBSCRIPT_EXPR = CursorKind(113)

# A builtin binary operation expression such as "x + y" or
# "x <= y".
CursorKind.BINARY_OPERATOR = CursorKind(114)

# Compound assignment such as "+=".
CursorKind.COMPOUND_ASSIGNMENT_OPERATOR = CursorKind(115)

# The ?: ternary operator.
CursorKind.CONDITIONAL_OPERATOR = CursorKind(116)

# An explicit cast in C (C99 6.5.4) or a C-style cast in C++
# (C++ [expr.cast]), which uses the syntax (Type)expr.
#
# For example: (int)f.
CursorKind.CSTYLE_CAST_EXPR = CursorKind(117)

# [C99 6.5.2.5]
CursorKind.COMPOUND_LITERAL_EXPR = CursorKind(118)

# Describes an C or C++ initializer list.
CursorKind.INIT_LIST_EXPR = CursorKind(119)

# The GNU address of label extension, representing &&label.
CursorKind.ADDR_LABEL_EXPR = CursorKind(120)

# This is the GNU Statement Expression extension: ({int X=4; X;})
CursorKind.StmtExpr = CursorKind(121)

# Represents a C11 generic selection.
CursorKind.GENERIC_SELECTION_EXPR = CursorKind(122)

# Implements the GNU __null extension, which is a name for a null
# pointer constant that has integral type (e.g., int or long) and is the same
# size and alignment as a pointer.
#
# The __null extension is typically only used by system headers, which define
# NULL as __null in C++ rather than using 0 (which is an integer that may not
# match the size of a pointer).
CursorKind.GNU_NULL_EXPR = CursorKind(123)

# C++'s static_cast<> expression.
CursorKind.CXX_STATIC_CAST_EXPR = CursorKind(124)

# C++'s dynamic_cast<> expression.
CursorKind.CXX_DYNAMIC_CAST_EXPR = CursorKind(125)

# C++'s reinterpret_cast<> expression.
CursorKind.CXX_REINTERPRET_CAST_EXPR = CursorKind(126)

# C++'s const_cast<> expression.
CursorKind.CXX_CONST_CAST_EXPR = CursorKind(127)

# Represents an explicit C++ type conversion that uses "functional"
# notion (C++ [expr.type.conv]).
#
# Example:
# \code
#   x = int(0.5);
# \endcode
CursorKind.CXX_FUNCTIONAL_CAST_EXPR = CursorKind(128)

# A C++ typeid expression (C++ [expr.typeid]).
CursorKind.CXX_TYPEID_EXPR = CursorKind(129)

# [C++ 2.13.5] C++ Boolean Literal.
CursorKind.CXX_BOOL_LITERAL_EXPR = CursorKind(130)

# [C++0x 2.14.7] C++ Pointer Literal.
CursorKind.CXX_NULL_PTR_LITERAL_EXPR = CursorKind(131)

# Represents the "this" expression in C++
CursorKind.CXX_THIS_EXPR = CursorKind(132)

# [C++ 15] C++ Throw Expression.
#
# This handles 'throw' and 'throw' assignment-expression. When
# assignment-expression isn't present, Op will be null.
CursorKind.CXX_THROW_EXPR = CursorKind(133)

# A new expression for memory allocation and constructor calls, e.g:
# "new CXXNewExpr(foo)".
CursorKind.CXX_NEW_EXPR = CursorKind(134)

# A delete expression for memory deallocation and destructor calls,
# e.g. "delete[] pArray".
CursorKind.CXX_DELETE_EXPR = CursorKind(135)

# Represents a unary expression.
CursorKind.CXX_UNARY_EXPR = CursorKind(136)

# ObjCStringLiteral, used for Objective-C string literals i.e. "foo".
CursorKind.OBJC_STRING_LITERAL = CursorKind(137)

# ObjCEncodeExpr, used for in Objective-C.
CursorKind.OBJC_ENCODE_EXPR = CursorKind(138)

# ObjCSelectorExpr used for in Objective-C.
CursorKind.OBJC_SELECTOR_EXPR = CursorKind(139)

# Objective-C's protocol expression.
CursorKind.OBJC_PROTOCOL_EXPR = CursorKind(140)

# An Objective-C "bridged" cast expression, which casts between
# Objective-C pointers and C pointers, transferring ownership in the process.
#
# \code
#   NSString *str = (__bridge_transfer NSString *)CFCreateString();
# \endcode
CursorKind.OBJC_BRIDGE_CAST_EXPR = CursorKind(141)

# Represents a C++0x pack expansion that produces a sequence of
# expressions.
#
# A pack expansion expression contains a pattern (which itself is an
# expression) followed by an ellipsis. For example:
CursorKind.PACK_EXPANSION_EXPR = CursorKind(142)

# Represents an expression that computes the length of a parameter
# pack.
CursorKind.SIZE_OF_PACK_EXPR = CursorKind(143)

# Represents a C++ lambda expression that produces a local function
# object.
#
#  \code
#  void abssort(float *x, unsigned N) {
#    std::sort(x, x + N,
#              [](float a, float b) {
#                return std::abs(a) < std::abs(b);
#              });
#  }
#  \endcode
CursorKind.LAMBDA_EXPR = CursorKind(144)

# Objective-c Boolean Literal.
CursorKind.OBJ_BOOL_LITERAL_EXPR = CursorKind(145)

# Represents the "self" expression in a ObjC method.
CursorKind.OBJ_SELF_EXPR = CursorKind(146)


# A statement whose specific kind is not exposed via this interface.
#
# Unexposed statements have the same operations as any other kind of statement;
# one can extract their location information, spelling, children, etc. However,
# the specific kind of the statement is not reported.
CursorKind.UNEXPOSED_STMT = CursorKind(200)

# A labelled statement in a function.
CursorKind.LABEL_STMT = CursorKind(201)

# A compound statement
CursorKind.COMPOUND_STMT = CursorKind(202)

# A case statement.
CursorKind.CASE_STMT = CursorKind(203)

# A default statement.
CursorKind.DEFAULT_STMT = CursorKind(204)

# An if statement.
CursorKind.IF_STMT = CursorKind(205)

# A switch statement.
CursorKind.SWITCH_STMT = CursorKind(206)

# A while statement.
CursorKind.WHILE_STMT = CursorKind(207)

# A do statement.
CursorKind.DO_STMT = CursorKind(208)

# A for statement.
CursorKind.FOR_STMT = CursorKind(209)

# A goto statement.
CursorKind.GOTO_STMT = CursorKind(210)

# An indirect goto statement.
CursorKind.INDIRECT_GOTO_STMT = CursorKind(211)

# A continue statement.
CursorKind.CONTINUE_STMT = CursorKind(212)

# A break statement.
CursorKind.BREAK_STMT = CursorKind(213)

# A return statement.
CursorKind.RETURN_STMT = CursorKind(214)

# A GNU-style inline assembler statement.
CursorKind.ASM_STMT = CursorKind(215)

# Objective-C's overall @try-@catch-@finally statement.
CursorKind.OBJC_AT_TRY_STMT = CursorKind(216)

# Objective-C's @catch statement.
CursorKind.OBJC_AT_CATCH_STMT = CursorKind(217)

# Objective-C's @finally statement.
CursorKind.OBJC_AT_FINALLY_STMT = CursorKind(218)

# Objective-C's @throw statement.
CursorKind.OBJC_AT_THROW_STMT = CursorKind(219)

# Objective-C's @synchronized statement.
CursorKind.OBJC_AT_SYNCHRONIZED_STMT = CursorKind(220)

# Objective-C's autorealease pool statement.
CursorKind.OBJC_AUTORELEASE_POOL_STMT = CursorKind(221)

# Objective-C's for collection statement.
CursorKind.OBJC_FOR_COLLECTION_STMT = CursorKind(222)

# C++'s catch statement.
CursorKind.CXX_CATCH_STMT = CursorKind(223)

# C++'s try statement.
CursorKind.CXX_TRY_STMT = CursorKind(224)

# C++'s for (* : *) statement.
CursorKind.CXX_FOR_RANGE_STMT = CursorKind(225)

# Windows Structured Exception Handling's try statement.
CursorKind.SEH_TRY_STMT = CursorKind(226)

# Windows Structured Exception Handling's except statement.
CursorKind.SEH_EXCEPT_STMT = CursorKind(227)

# Windows Structured Exception Handling's finally statement.
CursorKind.SEH_FINALLY_STMT = CursorKind(228)

# A MS inline assembly statement extension.
CursorKind.MS_ASM_STMT = CursorKind(229)

# The null statement.
CursorKind.NULL_STMT = CursorKind(230)

# Adaptor class for mixing declarations with statements and expressions.
CursorKind.DECL_STMT = CursorKind(231)

###
# Other Kinds

# Cursor that represents the translation unit itself.
#
# The translation unit cursor exists primarily to act as the root cursor for
# traversing the contents of a translation unit.
CursorKind.TRANSLATION_UNIT = CursorKind(300)

###
# Attributes

# An attribute whoe specific kind is note exposed via this interface
CursorKind.UNEXPOSED_ATTR = CursorKind(400)

CursorKind.IB_ACTION_ATTR = CursorKind(401)
CursorKind.IB_OUTLET_ATTR = CursorKind(402)
CursorKind.IB_OUTLET_COLLECTION_ATTR = CursorKind(403)

CursorKind.CXX_FINAL_ATTR = CursorKind(404)
CursorKind.CXX_OVERRIDE_ATTR = CursorKind(405)
CursorKind.ANNOTATE_ATTR = CursorKind(406)
CursorKind.ASM_LABEL_ATTR = CursorKind(407)
CursorKind.PACKED_ATTR = CursorKind(408)

###
# Preprocessing
CursorKind.PREPROCESSING_DIRECTIVE = CursorKind(500)
CursorKind.MACRO_DEFINITION = CursorKind(501)
CursorKind.MACRO_INSTANTIATION = CursorKind(502)
CursorKind.INCLUSION_DIRECTIVE = CursorKind(503)

###
# Extra declaration

# A module import declaration.
CursorKind.MODULE_IMPORT_DECL = CursorKind(600)

### Cursors ###

class Cursor(Structure):
    """
    The Cursor class represents a reference to an element within the AST. It
    acts as a kind of iterator.
    """
    _fields_ = [("_kind_id", c_int), ("xdata", c_int), ("data", c_void_p * 3)]

    @staticmethod
    def from_location(tu, location):
        # We store a reference to the TU in the instance so the TU won't get
        # collected before the cursor.
        cursor = conf.lib.clang_getCursor(tu, location)
        cursor._tu = tu

        return cursor

    def __eq__(self, other):
        return conf.lib.clang_equalCursors(self, other)

    def __ne__(self, other):
        return not self.__eq__(other)

    def is_definition(self):
        """
        Returns true if the declaration pointed at by the cursor is also a
        definition of that entity.
        """
        return conf.lib.clang_isCursorDefinition(self)

    def is_static_method(self):
        """Returns True if the cursor refers to a C++ member function or member
        function template that is declared 'static'.
        """
        return conf.lib.clang_CXXMethod_isStatic(self)

    def get_definition(self):
        """
        If the cursor is a reference to a declaration or a declaration of
        some entity, return a cursor that points to the definition of that
        entity.
        """
        # TODO: Should probably check that this is either a reference or
        # declaration prior to issuing the lookup.
        return conf.lib.clang_getCursorDefinition(self)

    def get_usr(self):
        """Return the Unified Symbol Resultion (USR) for the entity referenced
        by the given cursor (or None).

        A Unified Symbol Resolution (USR) is a string that identifies a
        particular entity (function, class, variable, etc.) within a
        program. USRs can be compared across translation units to determine,
        e.g., when references in one translation refer to an entity defined in
        another translation unit."""
        return conf.lib.clang_getCursorUSR(self)

    @property
    def kind(self):
        """Return the kind of this cursor."""
        return CursorKind.from_id(self._kind_id)

    @property
    def spelling(self):
        """Return the spelling of the entity pointed at by the cursor."""
        if not self.kind.is_declaration():
            # FIXME: clang_getCursorSpelling should be fixed to not assert on
            # this, for consistency with clang_getCursorUSR.
            return None
        if not hasattr(self, '_spelling'):
            self._spelling = conf.lib.clang_getCursorSpelling(self)

        return self._spelling

    @property
    def displayname(self):
        """
        Return the display name for the entity referenced by this cursor.

        The display name contains extra information that helps identify the cursor,
        such as the parameters of a function or template or the arguments of a
        class template specialization.
        """
        if not hasattr(self, '_displayname'):
            self._displayname = conf.lib.clang_getCursorDisplayName(self)

        return self._displayname

    @property
    def location(self):
        """
        Return the source location (the starting character) of the entity
        pointed at by the cursor.
        """
        if not hasattr(self, '_loc'):
            self._loc = conf.lib.clang_getCursorLocation(self)

        return self._loc

    @property
    def extent(self):
        """
        Return the source range (the range of text) occupied by the entity
        pointed at by the cursor.
        """
        if not hasattr(self, '_extent'):
            self._extent = conf.lib.clang_getCursorExtent(self)

        return self._extent

    @property
    def type(self):
        """
        Retrieve the Type (if any) of the entity pointed at by the cursor.
        """
        if not hasattr(self, '_type'):
            self._type = conf.lib.clang_getCursorType(self)

        return self._type

    @property
    def canonical(self):
        """Return the canonical Cursor corresponding to this Cursor.

        The canonical cursor is the cursor which is representative for the
        underlying entity. For example, if you have multiple forward
        declarations for the same class, the canonical cursor for the forward
        declarations will be identical.
        """
        if not hasattr(self, '_canonical'):
            self._canonical = conf.lib.clang_getCanonicalCursor(self)

        return self._canonical

    @property
    def result_type(self):
        """Retrieve the Type of the result for this Cursor."""
        if not hasattr(self, '_result_type'):
            self._result_type = conf.lib.clang_getResultType(self.type)

        return self._result_type

    @property
    def underlying_typedef_type(self):
        """Return the underlying type of a typedef declaration.

        Returns a Type for the typedef this cursor is a declaration for. If
        the current cursor is not a typedef, this raises.
        """
        if not hasattr(self, '_underlying_type'):
            assert self.kind.is_declaration()
            self._underlying_type = \
              conf.lib.clang_getTypedefDeclUnderlyingType(self)

        return self._underlying_type

    @property
    def enum_type(self):
        """Return the integer type of an enum declaration.

        Returns a Type corresponding to an integer. If the cursor is not for an
        enum, this raises.
        """
        if not hasattr(self, '_enum_type'):
            assert self.kind == CursorKind.ENUM_DECL
            self._enum_type = conf.lib.clang_getEnumDeclIntegerType(self)

        return self._enum_type

    @property
    def enum_value(self):
        """Return the value of an enum constant."""
        if not hasattr(self, '_enum_value'):
            assert self.kind == CursorKind.ENUM_CONSTANT_DECL
            # Figure out the underlying type of the enum to know if it
            # is a signed or unsigned quantity.
            underlying_type = self.type
            if underlying_type.kind == TypeKind.ENUM:
                underlying_type = underlying_type.get_declaration().enum_type
            if underlying_type.kind in (TypeKind.CHAR_U,
                                        TypeKind.UCHAR,
                                        TypeKind.CHAR16,
                                        TypeKind.CHAR32,
                                        TypeKind.USHORT,
                                        TypeKind.UINT,
                                        TypeKind.ULONG,
                                        TypeKind.ULONGLONG,
                                        TypeKind.UINT128):
                self._enum_value = \
                  conf.lib.clang_getEnumConstantDeclUnsignedValue(self)
            else:
                self._enum_value = conf.lib.clang_getEnumConstantDeclValue(self)
        return self._enum_value

    @property
    def objc_type_encoding(self):
        """Return the Objective-C type encoding as a str."""
        if not hasattr(self, '_objc_type_encoding'):
            self._objc_type_encoding = \
              conf.lib.clang_getDeclObjCTypeEncoding(self)

        return self._objc_type_encoding

    @property
    def hash(self):
        """Returns a hash of the cursor as an int."""
        if not hasattr(self, '_hash'):
            self._hash = conf.lib.clang_hashCursor(self)

        return self._hash

    @property
    def semantic_parent(self):
        """Return the semantic parent for this cursor."""
        if not hasattr(self, '_semantic_parent'):
            self._semantic_parent = conf.lib.clang_getCursorSemanticParent(self)

        return self._semantic_parent

    @property
    def lexical_parent(self):
        """Return the lexical parent for this cursor."""
        if not hasattr(self, '_lexical_parent'):
            self._lexical_parent = conf.lib.clang_getCursorLexicalParent(self)

        return self._lexical_parent

    @property
    def translation_unit(self):
        """Returns the TranslationUnit to which this Cursor belongs."""
        # If this triggers an AttributeError, the instance was not properly
        # created.
        return self._tu

    @property
    def referenced(self):
        """
        For a cursor that is a reference, returns a cursor
        representing the entity that it references.
        """
        if not hasattr(self, '_referenced'):
            self._referenced = conf.lib.clang_getCursorReferenced(self)

        return self._referenced

    def get_arguments(self):
        """Return an iterator for accessing the arguments of this cursor."""
        num_args = conf.lib.clang_Cursor_getNumArguments(self)
        for i in range(0, num_args):
            yield conf.lib.clang_Cursor_getArgument(self, i)

    def get_children(self):
        """Return an iterator for accessing the children of this cursor."""

        # FIXME: Expose iteration from CIndex, PR6125.
        def visitor(child, parent, children):
            # FIXME: Document this assertion in API.
            # FIXME: There should just be an isNull method.
            assert child != conf.lib.clang_getNullCursor()

            # Create reference to TU so it isn't GC'd before Cursor.
            child._tu = self._tu
            children.append(child)
            return 1 # continue
        children = []
        conf.lib.clang_visitChildren(self, callbacks['cursor_visit'](visitor),
            children)
        return iter(children)

    def get_tokens(self):
        """Obtain Token instances formulating that compose this Cursor.

        This is a generator for Token instances. It returns all tokens which
        occupy the extent this cursor occupies.
        """
        return TokenGroup.get_tokens(self._tu, self.extent)

    def is_bitfield(self):
        """
        Check if the field is a bitfield.
        """
        return conf.lib.clang_Cursor_isBitField(self)

    def get_bitfield_width(self):
        """
        Retrieve the width of a bitfield.
        """
        return conf.lib.clang_getFieldDeclBitWidth(self)

    @staticmethod
    def from_result(res, fn, args):
        assert isinstance(res, Cursor)
        # FIXME: There should just be an isNull method.
        if res == conf.lib.clang_getNullCursor():
            return None

        # Store a reference to the TU in the Python object so it won't get GC'd
        # before the Cursor.
        tu = None
        for arg in args:
            if isinstance(arg, TranslationUnit):
                tu = arg
                break

            if hasattr(arg, 'translation_unit'):
                tu = arg.translation_unit
                break

        assert tu is not None

        res._tu = tu
        return res

    @staticmethod
    def from_cursor_result(res, fn, args):
        assert isinstance(res, Cursor)
        if res == conf.lib.clang_getNullCursor():
            return None

        res._tu = args[0]._tu
        return res

### Type Kinds ###

class TypeKind(object):
    """
    Describes the kind of type.
    """

    # The unique kind objects, indexed by id.
    _kinds = []
    _name_map = None

    def __init__(self, value):
        if value >= len(TypeKind._kinds):
            TypeKind._kinds += [None] * (value - len(TypeKind._kinds) + 1)
        if TypeKind._kinds[value] is not None:
            raise ValueError,'TypeKind already loaded'
        self.value = value
        TypeKind._kinds[value] = self
        TypeKind._name_map = None

    def from_param(self):
        return self.value

    @property
    def name(self):
        """Get the enumeration name of this cursor kind."""
        if self._name_map is None:
            self._name_map = {}
            for key,value in TypeKind.__dict__.items():
                if isinstance(value,TypeKind):
                    self._name_map[value] = key
        return self._name_map[self]

    @property
    def spelling(self):
        """Retrieve the spelling of this TypeKind."""
        return conf.lib.clang_getTypeKindSpelling(self.value)

    @staticmethod
    def from_id(id):
        if id >= len(TypeKind._kinds) or TypeKind._kinds[id] is None:
            raise ValueError,'Unknown type kind %d' % id
        return TypeKind._kinds[id]

    def __repr__(self):
        return 'TypeKind.%s' % (self.name,)

TypeKind.INVALID = TypeKind(0)
TypeKind.UNEXPOSED = TypeKind(1)
TypeKind.VOID = TypeKind(2)
TypeKind.BOOL = TypeKind(3)
TypeKind.CHAR_U = TypeKind(4)
TypeKind.UCHAR = TypeKind(5)
TypeKind.CHAR16 = TypeKind(6)
TypeKind.CHAR32 = TypeKind(7)
TypeKind.USHORT = TypeKind(8)
TypeKind.UINT = TypeKind(9)
TypeKind.ULONG = TypeKind(10)
TypeKind.ULONGLONG = TypeKind(11)
TypeKind.UINT128 = TypeKind(12)
TypeKind.CHAR_S = TypeKind(13)
TypeKind.SCHAR = TypeKind(14)
TypeKind.WCHAR = TypeKind(15)
TypeKind.SHORT = TypeKind(16)
TypeKind.INT = TypeKind(17)
TypeKind.LONG = TypeKind(18)
TypeKind.LONGLONG = TypeKind(19)
TypeKind.INT128 = TypeKind(20)
TypeKind.FLOAT = TypeKind(21)
TypeKind.DOUBLE = TypeKind(22)
TypeKind.LONGDOUBLE = TypeKind(23)
TypeKind.NULLPTR = TypeKind(24)
TypeKind.OVERLOAD = TypeKind(25)
TypeKind.DEPENDENT = TypeKind(26)
TypeKind.OBJCID = TypeKind(27)
TypeKind.OBJCCLASS = TypeKind(28)
TypeKind.OBJCSEL = TypeKind(29)
TypeKind.COMPLEX = TypeKind(100)
TypeKind.POINTER = TypeKind(101)
TypeKind.BLOCKPOINTER = TypeKind(102)
TypeKind.LVALUEREFERENCE = TypeKind(103)
TypeKind.RVALUEREFERENCE = TypeKind(104)
TypeKind.RECORD = TypeKind(105)
TypeKind.ENUM = TypeKind(106)
TypeKind.TYPEDEF = TypeKind(107)
TypeKind.OBJCINTERFACE = TypeKind(108)
TypeKind.OBJCOBJECTPOINTER = TypeKind(109)
TypeKind.FUNCTIONNOPROTO = TypeKind(110)
TypeKind.FUNCTIONPROTO = TypeKind(111)
TypeKind.CONSTANTARRAY = TypeKind(112)
TypeKind.VECTOR = TypeKind(113)
TypeKind.INCOMPLETEARRAY = TypeKind(114)
TypeKind.VARIABLEARRAY = TypeKind(115)
TypeKind.DEPENDENTSIZEDARRAY = TypeKind(116)

class Type(Structure):
    """
    The type of an element in the abstract syntax tree.
    """
    _fields_ = [("_kind_id", c_int), ("data", c_void_p * 2)]

    @property
    def kind(self):
        """Return the kind of this type."""
        return TypeKind.from_id(self._kind_id)

    def argument_types(self):
        """Retrieve a container for the non-variadic arguments for this type.

        The returned object is iterable and indexable. Each item in the
        container is a Type instance.
        """
        class ArgumentsIterator(collections.Sequence):
            def __init__(self, parent):
                self.parent = parent
                self.length = None

            def __len__(self):
                if self.length is None:
                    self.length = conf.lib.clang_getNumArgTypes(self.parent)

                return self.length

            def __getitem__(self, key):
                # FIXME Support slice objects.
                if not isinstance(key, int):
                    raise TypeError("Must supply a non-negative int.")

                if key < 0:
                    raise IndexError("Only non-negative indexes are accepted.")

                if key >= len(self):
                    raise IndexError("Index greater than container length: "
                                     "%d > %d" % ( key, len(self) ))

                result = conf.lib.clang_getArgType(self.parent, key)
                if result.kind == TypeKind.INVALID:
                    raise IndexError("Argument could not be retrieved.")

                return result

        assert self.kind == TypeKind.FUNCTIONPROTO
        return ArgumentsIterator(self)

    @property
    def element_type(self):
        """Retrieve the Type of elements within this Type.

        If accessed on a type that is not an array, complex, or vector type, an
        exception will be raised.
        """
        result = conf.lib.clang_getElementType(self)
        if result.kind == TypeKind.INVALID:
            raise Exception('Element type not available on this type.')

        return result

    @property
    def element_count(self):
        """Retrieve the number of elements in this type.

        Returns an int.

        If the Type is not an array or vector, this raises.
        """
        result = conf.lib.clang_getNumElements(self)
        if result < 0:
            raise Exception('Type does not have elements.')

        return result

    @property
    def translation_unit(self):
        """The TranslationUnit to which this Type is associated."""
        # If this triggers an AttributeError, the instance was not properly
        # instantiated.
        return self._tu

    @staticmethod
    def from_result(res, fn, args):
        assert isinstance(res, Type)

        tu = None
        for arg in args:
            if hasattr(arg, 'translation_unit'):
                tu = arg.translation_unit
                break

        assert tu is not None
        res._tu = tu

        return res

    def get_canonical(self):
        """
        Return the canonical type for a Type.

        Clang's type system explicitly models typedefs and all the
        ways a specific type can be represented.  The canonical type
        is the underlying type with all the "sugar" removed.  For
        example, if 'T' is a typedef for 'int', the canonical type for
        'T' would be 'int'.
        """
        return conf.lib.clang_getCanonicalType(self)

    def is_const_qualified(self):
        """Determine whether a Type has the "const" qualifier set.

        This does not look through typedefs that may have added "const"
        at a different level.
        """
        return conf.lib.clang_isConstQualifiedType(self)

    def is_volatile_qualified(self):
        """Determine whether a Type has the "volatile" qualifier set.

        This does not look through typedefs that may have added "volatile"
        at a different level.
        """
        return conf.lib.clang_isVolatileQualifiedType(self)

    def is_restrict_qualified(self):
        """Determine whether a Type has the "restrict" qualifier set.

        This does not look through typedefs that may have added "restrict" at
        a different level.
        """
        return conf.lib.clang_isRestrictQualifiedType(self)

    def is_function_variadic(self):
        """Determine whether this function Type is a variadic function type."""
        assert self.kind == TypeKind.FUNCTIONPROTO

        return conf.lib.clang_isFunctionTypeVariadic(self)

    def is_pod(self):
        """Determine whether this Type represents plain old data (POD)."""
        return conf.lib.clang_isPODType(self)

    def get_pointee(self):
        """
        For pointer types, returns the type of the pointee.
        """
        return conf.lib.clang_getPointeeType(self)

    def get_declaration(self):
        """
        Return the cursor for the declaration of the given type.
        """
        return conf.lib.clang_getTypeDeclaration(self)

    def get_result(self):
        """
        Retrieve the result type associated with a function type.
        """
        return conf.lib.clang_getResultType(self)

    def get_array_element_type(self):
        """
        Retrieve the type of the elements of the array type.
        """
        return conf.lib.clang_getArrayElementType(self)

    def get_array_size(self):
        """
        Retrieve the size of the constant array.
        """
        return conf.lib.clang_getArraySize(self)

    def get_align(self):
        """
        Retrieve the alignment of the record.
        """
        return conf.lib.clang_Type_getAlignOf(self)

    def get_size(self):
        """
        Retrieve the size of the record.
        """
        return conf.lib.clang_Type_getSizeOf(self)

    def get_offset(self, fieldname):
        """
        Retrieve the offset of a field in the record.
        """
        return conf.lib.clang_Type_getOffsetOf(self, c_char_p(fieldname))

    def __eq__(self, other):
        if type(other) != type(self):
            return False

        return conf.lib.clang_equalTypes(self, other)

    def __ne__(self, other):
        return not self.__eq__(other)

## CIndex Objects ##

# CIndex objects (derived from ClangObject) are essentially lightweight
# wrappers attached to some underlying object, which is exposed via CIndex as
# a void*.

class ClangObject(object):
    """
    A helper for Clang objects. This class helps act as an intermediary for
    the ctypes library and the Clang CIndex library.
    """
    def __init__(self, obj):
        assert isinstance(obj, c_object_p) and obj
        self.obj = self._as_parameter_ = obj

    def from_param(self):
        return self._as_parameter_


class _CXUnsavedFile(Structure):
    """Helper for passing unsaved file arguments."""
    _fields_ = [("name", c_char_p), ("contents", c_char_p), ('length', c_ulong)]

# Functions calls through the python interface are rather slow. Fortunately,
# for most symboles, we do not need to perform a function call. Their spelling
# never changes and is consequently provided by this spelling cache.
SpellingCache = {
            # 0: CompletionChunk.Kind("Optional"),
            # 1: CompletionChunk.Kind("TypedText"),
            # 2: CompletionChunk.Kind("Text"),
            # 3: CompletionChunk.Kind("Placeholder"),
            # 4: CompletionChunk.Kind("Informative"),
            # 5 : CompletionChunk.Kind("CurrentParameter"),
            6: '(',   # CompletionChunk.Kind("LeftParen"),
            7: ')',   # CompletionChunk.Kind("RightParen"),
            8: ']',   # CompletionChunk.Kind("LeftBracket"),
            9: ']',   # CompletionChunk.Kind("RightBracket"),
            10: '{',  # CompletionChunk.Kind("LeftBrace"),
            11: '}',  # CompletionChunk.Kind("RightBrace"),
            12: '<',  # CompletionChunk.Kind("LeftAngle"),
            13: '>',  # CompletionChunk.Kind("RightAngle"),
            14: ', ', # CompletionChunk.Kind("Comma"),
            # 15: CompletionChunk.Kind("ResultType"),
            16: ':',  # CompletionChunk.Kind("Colon"),
            17: ';',  # CompletionChunk.Kind("SemiColon"),
            18: '=',  # CompletionChunk.Kind("Equal"),
            19: ' ',  # CompletionChunk.Kind("HorizontalSpace"),
            # 20: CompletionChunk.Kind("VerticalSpace")
}

class CompletionChunk:
    class Kind:
        def __init__(self, name):
            self.name = name

        def __str__(self):
            return self.name

        def __repr__(self):
            return "<ChunkKind: %s>" % self

    def __init__(self, completionString, key):
        self.cs = completionString
        self.key = key
        self.__kindNumberCache = -1

    def __repr__(self):
        return "{'" + self.spelling + "', " + str(self.kind) + "}"

    @CachedProperty
    def spelling(self):
        if self.__kindNumber in SpellingCache:
                return SpellingCache[self.__kindNumber]
        return conf.lib.clang_getCompletionChunkText(self.cs, self.key).spelling

    # We do not use @CachedProperty here, as the manual implementation is
    # apparently still significantly faster. Please profile carefully if you
    # would like to add CachedProperty back.
    @property
    def __kindNumber(self):
        if self.__kindNumberCache == -1:
            self.__kindNumberCache = \
                conf.lib.clang_getCompletionChunkKind(self.cs, self.key)
        return self.__kindNumberCache

    @CachedProperty
    def kind(self):
        return completionChunkKindMap[self.__kindNumber]

    @CachedProperty
    def string(self):
        res = conf.lib.clang_getCompletionChunkCompletionString(self.cs,
                                                                self.key)

        if (res):
          return CompletionString(res)
        else:
          None

    def isKindOptional(self):
      return self.__kindNumber == 0

    def isKindTypedText(self):
      return self.__kindNumber == 1

    def isKindPlaceHolder(self):
      return self.__kindNumber == 3

    def isKindInformative(self):
      return self.__kindNumber == 4

    def isKindResultType(self):
      return self.__kindNumber == 15

completionChunkKindMap = {
            0: CompletionChunk.Kind("Optional"),
            1: CompletionChunk.Kind("TypedText"),
            2: CompletionChunk.Kind("Text"),
            3: CompletionChunk.Kind("Placeholder"),
            4: CompletionChunk.Kind("Informative"),
            5: CompletionChunk.Kind("CurrentParameter"),
            6: CompletionChunk.Kind("LeftParen"),
            7: CompletionChunk.Kind("RightParen"),
            8: CompletionChunk.Kind("LeftBracket"),
            9: CompletionChunk.Kind("RightBracket"),
            10: CompletionChunk.Kind("LeftBrace"),
            11: CompletionChunk.Kind("RightBrace"),
            12: CompletionChunk.Kind("LeftAngle"),
            13: CompletionChunk.Kind("RightAngle"),
            14: CompletionChunk.Kind("Comma"),
            15: CompletionChunk.Kind("ResultType"),
            16: CompletionChunk.Kind("Colon"),
            17: CompletionChunk.Kind("SemiColon"),
            18: CompletionChunk.Kind("Equal"),
            19: CompletionChunk.Kind("HorizontalSpace"),
            20: CompletionChunk.Kind("VerticalSpace")}

class CompletionString(ClangObject):
    class Availability:
        def __init__(self, name):
            self.name = name

        def __str__(self):
            return self.name

        def __repr__(self):
            return "<Availability: %s>" % self

    def __len__(self):
        self.num_chunks

    @CachedProperty
    def num_chunks(self):
        return conf.lib.clang_getNumCompletionChunks(self.obj)

    def __getitem__(self, key):
        if self.num_chunks <= key:
            raise IndexError
        return CompletionChunk(self.obj, key)

    @property
    def priority(self):
        return conf.lib.clang_getCompletionPriority(self.obj)

    @property
    def availability(self):
        res = conf.lib.clang_getCompletionAvailability(self.obj)
        return availabilityKinds[res]

    @property
    def briefComment(self):
        if conf.function_exists("clang_getCompletionBriefComment"):
            return conf.lib.clang_getCompletionBriefComment(self.obj)
        return _CXString()

    def __repr__(self):
        return " | ".join([str(a) for a in self]) \
               + " || Priority: " + str(self.priority) \
               + " || Availability: " + str(self.availability) \
               + " || Brief comment: " + str(self.briefComment.spelling)

availabilityKinds = {
            0: CompletionChunk.Kind("Available"),
            1: CompletionChunk.Kind("Deprecated"),
            2: CompletionChunk.Kind("NotAvailable"),
            3: CompletionChunk.Kind("NotAccessible")}

class CodeCompletionResult(Structure):
    _fields_ = [('cursorKind', c_int), ('completionString', c_object_p)]

    def __repr__(self):
        return str(CompletionString(self.completionString))

    @property
    def kind(self):
        return CursorKind.from_id(self.cursorKind)

    @property
    def string(self):
        return CompletionString(self.completionString)

class CCRStructure(Structure):
    _fields_ = [('results', POINTER(CodeCompletionResult)),
                ('numResults', c_int)]

    def __len__(self):
        return self.numResults

    def __getitem__(self, key):
        if len(self) <= key:
            raise IndexError

        return self.results[key]

class CodeCompletionResults(ClangObject):
    def __init__(self, ptr):
        assert isinstance(ptr, POINTER(CCRStructure)) and ptr
        self.ptr = self._as_parameter_ = ptr

    def from_param(self):
        return self._as_parameter_

    def __del__(self):
        conf.lib.clang_disposeCodeCompleteResults(self)

    @property
    def results(self):
        return self.ptr.contents

    @property
    def diagnostics(self):
        class DiagnosticsItr:
            def __init__(self, ccr):
                self.ccr= ccr

            def __len__(self):
                return int(\
                  conf.lib.clang_codeCompleteGetNumDiagnostics(self.ccr))

            def __getitem__(self, key):
                return conf.lib.clang_codeCompleteGetDiagnostic(self.ccr, key)

        return DiagnosticsItr(self)


class Index(ClangObject):
    """
    The Index type provides the primary interface to the Clang CIndex library,
    primarily by providing an interface for reading and parsing translation
    units.
    """

    @staticmethod
    def create(excludeDecls=False):
        """
        Create a new Index.
        Parameters:
        excludeDecls -- Exclude local declarations from translation units.
        """
        return Index(conf.lib.clang_createIndex(excludeDecls, 0))

    def __del__(self):
        conf.lib.clang_disposeIndex(self)

    def read(self, path):
        """Load a TranslationUnit from the given AST file."""
        return TranslationUnit.from_ast_file(path, self)

    def parse(self, path, args=None, unsaved_files=None, options = 0):
        """Load the translation unit from the given source code file by running
        clang and generating the AST before loading. Additional command line
        parameters can be passed to clang via the args parameter.

        In-memory contents for files can be provided by passing a list of pairs
        to as unsaved_files, the first item should be the filenames to be mapped
        and the second should be the contents to be substituted for the
        file. The contents may be passed as strings or file objects.

        If an error was encountered during parsing, a TranslationUnitLoadError
        will be raised.
        """
        return TranslationUnit.from_source(path, args, unsaved_files, options,
                                           self)

class TranslationUnit(ClangObject):
    """Represents a source code translation unit.

    This is one of the main types in the API. Any time you wish to interact
    with Clang's representation of a source file, you typically start with a
    translation unit.
    """

    # Default parsing mode.
    PARSE_NONE = 0

    # Instruct the parser to create a detailed processing record containing
    # metadata not normally retained.
    PARSE_DETAILED_PROCESSING_RECORD = 1

    # Indicates that the translation unit is incomplete. This is typically used
    # when parsing headers.
    PARSE_INCOMPLETE = 2

    # Instruct the parser to create a pre-compiled preamble for the translation
    # unit. This caches the preamble (included files at top of source file).
    # This is useful if the translation unit will be reparsed and you don't
    # want to incur the overhead of reparsing the preamble.
    PARSE_PRECOMPILED_PREAMBLE = 4

    # Cache code completion information on parse. This adds time to parsing but
    # speeds up code completion.
    PARSE_CACHE_COMPLETION_RESULTS = 8

    # Flags with values 16 and 32 are deprecated and intentionally omitted.

    # Do not parse function bodies. This is useful if you only care about
    # searching for declarations/definitions.
    PARSE_SKIP_FUNCTION_BODIES = 64

    # Used to indicate that brief documentation comments should be included
    # into the set of code completions returned from this translation unit.
    PARSE_INCLUDE_BRIEF_COMMENTS_IN_CODE_COMPLETION = 128

    @classmethod
    def from_source(cls, filename, args=None, unsaved_files=None, options=0,
                    index=None):
        """Create a TranslationUnit by parsing source.

        This is capable of processing source code both from files on the
        filesystem as well as in-memory contents.

        Command-line arguments that would be passed to clang are specified as
        a list via args. These can be used to specify include paths, warnings,
        etc. e.g. ["-Wall", "-I/path/to/include"].

        In-memory file content can be provided via unsaved_files. This is an
        iterable of 2-tuples. The first element is the str filename. The
        second element defines the content. Content can be provided as str
        source code or as file objects (anything with a read() method). If
        a file object is being used, content will be read until EOF and the
        read cursor will not be reset to its original position.

        options is a bitwise or of TranslationUnit.PARSE_XXX flags which will
        control parsing behavior.

        index is an Index instance to utilize. If not provided, a new Index
        will be created for this TranslationUnit.

        To parse source from the filesystem, the filename of the file to parse
        is specified by the filename argument. Or, filename could be None and
        the args list would contain the filename(s) to parse.

        To parse source from an in-memory buffer, set filename to the virtual
        filename you wish to associate with this source (e.g. "test.c"). The
        contents of that file are then provided in unsaved_files.

        If an error occurs, a TranslationUnitLoadError is raised.

        Please note that a TranslationUnit with parser errors may be returned.
        It is the caller's responsibility to check tu.diagnostics for errors.

        Also note that Clang infers the source language from the extension of
        the input filename. If you pass in source code containing a C++ class
        declaration with the filename "test.c" parsing will fail.
        """
        if args is None:
            args = []

        if unsaved_files is None:
            unsaved_files = []

        if index is None:
            index = Index.create()

        args_array = None
        if len(args) > 0:
            args_array = (c_char_p * len(args))(* args)

        unsaved_array = None
        if len(unsaved_files) > 0:
            unsaved_array = (_CXUnsavedFile * len(unsaved_files))()
            for i, (name, contents) in enumerate(unsaved_files):
                if hasattr(contents, "read"):
                    contents = contents.read()

                unsaved_array[i].name = name
                unsaved_array[i].contents = contents
                unsaved_array[i].length = len(contents)

        ptr = conf.lib.clang_parseTranslationUnit(index, filename, args_array,
                                    len(args), unsaved_array,
                                    len(unsaved_files), options)

        if not ptr:
            raise TranslationUnitLoadError("Error parsing translation unit.")

        return cls(ptr, index=index)

    @classmethod
    def from_ast_file(cls, filename, index=None):
        """Create a TranslationUnit instance from a saved AST file.

        A previously-saved AST file (provided with -emit-ast or
        TranslationUnit.save()) is loaded from the filename specified.

        If the file cannot be loaded, a TranslationUnitLoadError will be
        raised.

        index is optional and is the Index instance to use. If not provided,
        a default Index will be created.
        """
        if index is None:
            index = Index.create()

        ptr = conf.lib.clang_createTranslationUnit(index, filename)
        if not ptr:
            raise TranslationUnitLoadError(filename)

        return cls(ptr=ptr, index=index)

    def __init__(self, ptr, index):
        """Create a TranslationUnit instance.

        TranslationUnits should be created using one of the from_* @classmethod
        functions above. __init__ is only called internally.
        """
        assert isinstance(index, Index)

        ClangObject.__init__(self, ptr)

    def __del__(self):
        conf.lib.clang_disposeTranslationUnit(self)

    @property
    def cursor(self):
        """Retrieve the cursor that represents the given translation unit."""
        return conf.lib.clang_getTranslationUnitCursor(self)

    @property
    def spelling(self):
        """Get the original translation unit source file name."""
        return conf.lib.clang_getTranslationUnitSpelling(self)

    def get_includes(self):
        """
        Return an iterable sequence of FileInclusion objects that describe the
        sequence of inclusions in a translation unit. The first object in
        this sequence is always the input file. Note that this method will not
        recursively iterate over header files included through precompiled
        headers.
        """
        def visitor(fobj, lptr, depth, includes):
            if depth > 0:
                loc = lptr.contents
                includes.append(FileInclusion(loc.file, File(fobj), loc, depth))

        # Automatically adapt CIndex/ctype pointers to python objects
        includes = []
        conf.lib.clang_getInclusions(self,
                callbacks['translation_unit_includes'](visitor), includes)

        return iter(includes)

    def get_file(self, filename):
        """Obtain a File from this translation unit."""

        return File.from_name(self, filename)

    def get_location(self, filename, position):
        """Obtain a SourceLocation for a file in this translation unit.

        The position can be specified by passing:

          - Integer file offset. Initial file offset is 0.
          - 2-tuple of (line number, column number). Initial file position is
            (0, 0)
        """
        f = self.get_file(filename)

        if isinstance(position, int):
            return SourceLocation.from_offset(self, f, position)

        return SourceLocation.from_position(self, f, position[0], position[1])

    def get_extent(self, filename, locations):
        """Obtain a SourceRange from this translation unit.

        The bounds of the SourceRange must ultimately be defined by a start and
        end SourceLocation. For the locations argument, you can pass:

          - 2 SourceLocation instances in a 2-tuple or list.
          - 2 int file offsets via a 2-tuple or list.
          - 2 2-tuple or lists of (line, column) pairs in a 2-tuple or list.

        e.g.

        get_extent('foo.c', (5, 10))
        get_extent('foo.c', ((1, 1), (1, 15)))
        """
        f = self.get_file(filename)

        if len(locations) < 2:
            raise Exception('Must pass object with at least 2 elements')

        start_location, end_location = locations

        if hasattr(start_location, '__len__'):
            start_location = SourceLocation.from_position(self, f,
                start_location[0], start_location[1])
        elif isinstance(start_location, int):
            start_location = SourceLocation.from_offset(self, f,
                start_location)

        if hasattr(end_location, '__len__'):
            end_location = SourceLocation.from_position(self, f,
                end_location[0], end_location[1])
        elif isinstance(end_location, int):
            end_location = SourceLocation.from_offset(self, f, end_location)

        assert isinstance(start_location, SourceLocation)
        assert isinstance(end_location, SourceLocation)

        return SourceRange.from_locations(start_location, end_location)

    @property
    def diagnostics(self):
        """
        Return an iterable (and indexable) object containing the diagnostics.
        """
        class DiagIterator:
            def __init__(self, tu):
                self.tu = tu

            def __len__(self):
                return int(conf.lib.clang_getNumDiagnostics(self.tu))

            def __getitem__(self, key):
                diag = conf.lib.clang_getDiagnostic(self.tu, key)
                if not diag:
                    raise IndexError
                return Diagnostic(diag)

        return DiagIterator(self)

    def reparse(self, unsaved_files=None, options=0):
        """
        Reparse an already parsed translation unit.

        In-memory contents for files can be provided by passing a list of pairs
        as unsaved_files, the first items should be the filenames to be mapped
        and the second should be the contents to be substituted for the
        file. The contents may be passed as strings or file objects.
        """
        if unsaved_files is None:
            unsaved_files = []

        unsaved_files_array = 0
        if len(unsaved_files):
            unsaved_files_array = (_CXUnsavedFile * len(unsaved_files))()
            for i,(name,value) in enumerate(unsaved_files):
                if not isinstance(value, str):
                    # FIXME: It would be great to support an efficient version
                    # of this, one day.
                    value = value.read()
                    print value
                if not isinstance(value, str):
                    raise TypeError,'Unexpected unsaved file contents.'
                unsaved_files_array[i].name = name
                unsaved_files_array[i].contents = value
                unsaved_files_array[i].length = len(value)
        ptr = conf.lib.clang_reparseTranslationUnit(self, len(unsaved_files),
                unsaved_files_array, options)

    def save(self, filename):
        """Saves the TranslationUnit to a file.

        This is equivalent to passing -emit-ast to the clang frontend. The
        saved file can be loaded back into a TranslationUnit. Or, if it
        corresponds to a header, it can be used as a pre-compiled header file.

        If an error occurs while saving, a TranslationUnitSaveError is raised.
        If the error was TranslationUnitSaveError.ERROR_INVALID_TU, this means
        the constructed TranslationUnit was not valid at time of save. In this
        case, the reason(s) why should be available via
        TranslationUnit.diagnostics().

        filename -- The path to save the translation unit to.
        """
        options = conf.lib.clang_defaultSaveOptions(self)
        result = int(conf.lib.clang_saveTranslationUnit(self, filename,
                                                        options))
        if result != 0:
            raise TranslationUnitSaveError(result,
                'Error saving TranslationUnit.')

    def codeComplete(self, path, line, column, unsaved_files=None,
                     include_macros=False, include_code_patterns=False,
                     include_brief_comments=False):
        """
        Code complete in this translation unit.

        In-memory contents for files can be provided by passing a list of pairs
        as unsaved_files, the first items should be the filenames to be mapped
        and the second should be the contents to be substituted for the
        file. The contents may be passed as strings or file objects.
        """
        options = 0

        if include_macros:
            options += 1

        if include_code_patterns:
            options += 2

        if include_brief_comments:
            options += 4

        if unsaved_files is None:
            unsaved_files = []

        unsaved_files_array = 0
        if len(unsaved_files):
            unsaved_files_array = (_CXUnsavedFile * len(unsaved_files))()
            for i,(name,value) in enumerate(unsaved_files):
                if not isinstance(value, str):
                    # FIXME: It would be great to support an efficient version
                    # of this, one day.
                    value = value.read()
                    print value
                if not isinstance(value, str):
                    raise TypeError,'Unexpected unsaved file contents.'
                unsaved_files_array[i].name = name
                unsaved_files_array[i].contents = value
                unsaved_files_array[i].length = len(value)
        ptr = conf.lib.clang_codeCompleteAt(self, path, line, column,
                unsaved_files_array, len(unsaved_files), options)
        if ptr:
            return CodeCompletionResults(ptr)
        return None

    def get_tokens(self, locations=None, extent=None):
        """Obtain tokens in this translation unit.

        This is a generator for Token instances. The caller specifies a range
        of source code to obtain tokens for. The range can be specified as a
        2-tuple of SourceLocation or as a SourceRange. If both are defined,
        behavior is undefined.
        """
        if locations is not None:
            extent = SourceRange(start=locations[0], end=locations[1])

        return TokenGroup.get_tokens(self, extent)

class File(ClangObject):
    """
    The File class represents a particular source file that is part of a
    translation unit.
    """

    @staticmethod
    def from_name(translation_unit, file_name):
        """Retrieve a file handle within the given translation unit."""
        return File(conf.lib.clang_getFile(translation_unit, file_name))

    @property
    def name(self):
        """Return the complete file and path name of the file."""
        return conf.lib.clang_getCString(conf.lib.clang_getFileName(self))

    @property
    def time(self):
        """Return the last modification time of the file."""
        return conf.lib.clang_getFileTime(self)

    def __str__(self):
        return self.name

    def __repr__(self):
        return "<File: %s>" % (self.name)

    @staticmethod
    def from_cursor_result(res, fn, args):
        assert isinstance(res, File)

        # Copy a reference to the TranslationUnit to prevent premature GC.
        res._tu = args[0]._tu
        return res

class FileInclusion(object):
    """
    The FileInclusion class represents the inclusion of one source file by
    another via a '#include' directive or as the input file for the translation
    unit. This class provides information about the included file, the including
    file, the location of the '#include' directive and the depth of the included
    file in the stack. Note that the input file has depth 0.
    """

    def __init__(self, src, tgt, loc, depth):
        self.source = src
        self.include = tgt
        self.location = loc
        self.depth = depth

    @property
    def is_input_file(self):
        """True if the included file is the input file."""
        return self.depth == 0

class CompilationDatabaseError(Exception):
    """Represents an error that occurred when working with a CompilationDatabase

    Each error is associated to an enumerated value, accessible under
    e.cdb_error. Consumers can compare the value with one of the ERROR_
    constants in this class.
    """

    # An unknown error occured
    ERROR_UNKNOWN = 0

    # The database could not be loaded
    ERROR_CANNOTLOADDATABASE = 1

    def __init__(self, enumeration, message):
        assert isinstance(enumeration, int)

        if enumeration > 1:
            raise Exception("Encountered undefined CompilationDatabase error "
                            "constant: %d. Please file a bug to have this "
                            "value supported." % enumeration)

        self.cdb_error = enumeration
        Exception.__init__(self, 'Error %d: %s' % (enumeration, message))

class CompileCommand(object):
    """Represents the compile command used to build a file"""
    def __init__(self, cmd, ccmds):
        self.cmd = cmd
        # Keep a reference to the originating CompileCommands
        # to prevent garbage collection
        self.ccmds = ccmds

    @property
    def directory(self):
        """Get the working directory for this CompileCommand"""
        return conf.lib.clang_CompileCommand_getDirectory(self.cmd)

    @property
    def arguments(self):
        """
        Get an iterable object providing each argument in the
        command line for the compiler invocation as a _CXString.

        Invariant : the first argument is the compiler executable
        """
        length = conf.lib.clang_CompileCommand_getNumArgs(self.cmd)
        for i in xrange(length):
            yield conf.lib.clang_CompileCommand_getArg(self.cmd, i)

class CompileCommands(object):
    """
    CompileCommands is an iterable object containing all CompileCommand
    that can be used for building a specific file.
    """
    def __init__(self, ccmds):
        self.ccmds = ccmds

    def __del__(self):
        conf.lib.clang_CompileCommands_dispose(self.ccmds)

    def __len__(self):
        return int(conf.lib.clang_CompileCommands_getSize(self.ccmds))

    def __getitem__(self, i):
        cc = conf.lib.clang_CompileCommands_getCommand(self.ccmds, i)
        if not cc:
            raise IndexError
        return CompileCommand(cc, self)

    @staticmethod
    def from_result(res, fn, args):
        if not res:
            return None
        return CompileCommands(res)

class CompilationDatabase(ClangObject):
    """
    The CompilationDatabase is a wrapper class around
    clang::tooling::CompilationDatabase

    It enables querying how a specific source file can be built.
    """

    def __del__(self):
        conf.lib.clang_CompilationDatabase_dispose(self)

    @staticmethod
    def from_result(res, fn, args):
        if not res:
            raise CompilationDatabaseError(0,
                                           "CompilationDatabase loading failed")
        return CompilationDatabase(res)

    @staticmethod
    def fromDirectory(buildDir):
        """Builds a CompilationDatabase from the database found in buildDir"""
        errorCode = c_uint()
        try:
            cdb = conf.lib.clang_CompilationDatabase_fromDirectory(buildDir,
                byref(errorCode))
        except CompilationDatabaseError as e:
            raise CompilationDatabaseError(int(errorCode.value),
                                           "CompilationDatabase loading failed")
        return cdb

    def getCompileCommands(self, filename):
        """
        Get an iterable object providing all the CompileCommands available to
        build filename. Returns None if filename is not found in the database.
        """
        return conf.lib.clang_CompilationDatabase_getCompileCommands(self,
                                                                     filename)

class Token(Structure):
    """Represents a single token from the preprocessor.

    Tokens are effectively segments of source code. Source code is first parsed
    into tokens before being converted into the AST and Cursors.

    Tokens are obtained from parsed TranslationUnit instances. You currently
    can't create tokens manually.
    """
    _fields_ = [
        ('int_data', c_uint * 4),
        ('ptr_data', c_void_p)
    ]

    @property
    def spelling(self):
        """The spelling of this token.

        This is the textual representation of the token in source.
        """
        return conf.lib.clang_getTokenSpelling(self._tu, self)

    @property
    def kind(self):
        """Obtain the TokenKind of the current token."""
        return TokenKind.from_value(conf.lib.clang_getTokenKind(self))

    @property
    def location(self):
        """The SourceLocation this Token occurs at."""
        return conf.lib.clang_getTokenLocation(self._tu, self)

    @property
    def extent(self):
        """The SourceRange this Token occupies."""
        return conf.lib.clang_getTokenExtent(self._tu, self)

    @property
    def cursor(self):
        """The Cursor this Token corresponds to."""
        cursor = Cursor()

        conf.lib.clang_annotateTokens(self._tu, byref(self), 1, byref(cursor))

        return cursor

# Now comes the plumbing to hook up the C library.

# Register callback types in common container.
callbacks['translation_unit_includes'] = CFUNCTYPE(None, c_object_p,
        POINTER(SourceLocation), c_uint, py_object)
callbacks['cursor_visit'] = CFUNCTYPE(c_int, Cursor, Cursor, py_object)

# Functions strictly alphabetical order.
functionList = [
  ("clang_annotateTokens",
   [TranslationUnit, POINTER(Token), c_uint, POINTER(Cursor)]),

  ("clang_CompilationDatabase_dispose",
   [c_object_p]),

  ("clang_CompilationDatabase_fromDirectory",
   [c_char_p, POINTER(c_uint)],
   c_object_p,
   CompilationDatabase.from_result),

  ("clang_CompilationDatabase_getCompileCommands",
   [c_object_p, c_char_p],
   c_object_p,
   CompileCommands.from_result),

  ("clang_CompileCommands_dispose",
   [c_object_p]),

  ("clang_CompileCommands_getCommand",
   [c_object_p, c_uint],
   c_object_p),

  ("clang_CompileCommands_getSize",
   [c_object_p],
   c_uint),

  ("clang_CompileCommand_getArg",
   [c_object_p, c_uint],
   _CXString,
   _CXString.from_result),

  ("clang_CompileCommand_getDirectory",
   [c_object_p],
   _CXString,
   _CXString.from_result),

  ("clang_CompileCommand_getNumArgs",
   [c_object_p],
   c_uint),

  ("clang_codeCompleteAt",
   [TranslationUnit, c_char_p, c_int, c_int, c_void_p, c_int, c_int],
   POINTER(CCRStructure)),

  ("clang_codeCompleteGetDiagnostic",
   [CodeCompletionResults, c_int],
   Diagnostic),

  ("clang_codeCompleteGetNumDiagnostics",
   [CodeCompletionResults],
   c_int),

  ("clang_createIndex",
   [c_int, c_int],
   c_object_p),

  ("clang_createTranslationUnit",
   [Index, c_char_p],
   c_object_p),

  ("clang_CXXMethod_isPureVirtual",
   [Cursor],
   bool),

  ("clang_CXXMethod_isStatic",
   [Cursor],
   bool),

  ("clang_CXXMethod_isVirtual",
   [Cursor],
   bool),

  ("clang_defaultSaveOptions",
   [TranslationUnit],
   c_uint),

  ("clang_disposeCodeCompleteResults",
   [CodeCompletionResults]),

# ("clang_disposeCXTUResourceUsage",
#  [CXTUResourceUsage]),

  ("clang_disposeDiagnostic",
   [Diagnostic]),

  ("clang_disposeIndex",
   [Index]),

  ("clang_disposeString",
   [_CXString]),

  ("clang_disposeTokens",
   [TranslationUnit, POINTER(Token), c_uint]),

  ("clang_disposeTranslationUnit",
   [TranslationUnit]),

  ("clang_equalCursors",
   [Cursor, Cursor],
   bool),

  ("clang_equalLocations",
   [SourceLocation, SourceLocation],
   bool),

  ("clang_equalRanges",
   [SourceRange, SourceRange],
   bool),

  ("clang_equalTypes",
   [Type, Type],
   bool),

  ("clang_getArgType",
   [Type, c_uint],
   Type,
   Type.from_result),

  ("clang_getArrayElementType",
   [Type],
   Type,
   Type.from_result),

  ("clang_getArraySize",
   [Type],
   c_longlong),

  ("clang_getFieldDeclBitWidth",
   [Cursor],
   c_int),

  ("clang_getCanonicalCursor",
   [Cursor],
   Cursor,
   Cursor.from_cursor_result),

  ("clang_getCanonicalType",
   [Type],
   Type,
   Type.from_result),

  ("clang_getCompletionAvailability",
   [c_void_p],
   c_int),

  ("clang_getCompletionBriefComment",
   [c_void_p],
   _CXString),

  ("clang_getCompletionChunkCompletionString",
   [c_void_p, c_int],
   c_object_p),

  ("clang_getCompletionChunkKind",
   [c_void_p, c_int],
   c_int),

  ("clang_getCompletionChunkText",
   [c_void_p, c_int],
   _CXString),

  ("clang_getCompletionPriority",
   [c_void_p],
   c_int),

  ("clang_getCString",
   [_CXString],
   c_char_p),

  ("clang_getCursor",
   [TranslationUnit, SourceLocation],
   Cursor),

  ("clang_getCursorDefinition",
   [Cursor],
   Cursor,
   Cursor.from_result),

  ("clang_getCursorDisplayName",
   [Cursor],
   _CXString,
   _CXString.from_result),

  ("clang_getCursorExtent",
   [Cursor],
   SourceRange),

  ("clang_getCursorLexicalParent",
   [Cursor],
   Cursor,
   Cursor.from_cursor_result),

  ("clang_getCursorLocation",
   [Cursor],
   SourceLocation),

  ("clang_getCursorReferenced",
   [Cursor],
   Cursor,
   Cursor.from_result),

  ("clang_getCursorReferenceNameRange",
   [Cursor, c_uint, c_uint],
   SourceRange),

  ("clang_getCursorSemanticParent",
   [Cursor],
   Cursor,
   Cursor.from_cursor_result),

  ("clang_getCursorSpelling",
   [Cursor],
   _CXString,
   _CXString.from_result),

  ("clang_getCursorType",
   [Cursor],
   Type,
   Type.from_result),

  ("clang_getCursorUSR",
   [Cursor],
   _CXString,
   _CXString.from_result),

# ("clang_getCXTUResourceUsage",
#  [TranslationUnit],
#  CXTUResourceUsage),

  ("clang_getCXXAccessSpecifier",
   [Cursor],
   c_uint),

  ("clang_getDeclObjCTypeEncoding",
   [Cursor],
   _CXString,
   _CXString.from_result),

  ("clang_getDiagnostic",
   [c_object_p, c_uint],
   c_object_p),

  ("clang_getDiagnosticCategory",
   [Diagnostic],
   c_uint),

  ("clang_getDiagnosticCategoryName",
   [c_uint],
   _CXString,
   _CXString.from_result),

  ("clang_getDiagnosticFixIt",
   [Diagnostic, c_uint, POINTER(SourceRange)],
   _CXString,
   _CXString.from_result),

  ("clang_getDiagnosticLocation",
   [Diagnostic],
   SourceLocation),

  ("clang_getDiagnosticNumFixIts",
   [Diagnostic],
   c_uint),

  ("clang_getDiagnosticNumRanges",
   [Diagnostic],
   c_uint),

  ("clang_getDiagnosticOption",
   [Diagnostic, POINTER(_CXString)],
   _CXString,
   _CXString.from_result),

  ("clang_getDiagnosticRange",
   [Diagnostic, c_uint],
   SourceRange),

  ("clang_getDiagnosticSeverity",
   [Diagnostic],
   c_int),

  ("clang_getDiagnosticSpelling",
   [Diagnostic],
   _CXString,
   _CXString.from_result),

  ("clang_getElementType",
   [Type],
   Type,
   Type.from_result),

  ("clang_getEnumConstantDeclUnsignedValue",
   [Cursor],
   c_ulonglong),

  ("clang_getEnumConstantDeclValue",
   [Cursor],
   c_longlong),

  ("clang_getEnumDeclIntegerType",
   [Cursor],
   Type,
   Type.from_result),

  ("clang_getFile",
   [TranslationUnit, c_char_p],
   c_object_p),

  ("clang_getFileName",
   [File],
   _CXString), # TODO go through _CXString.from_result?

  ("clang_getFileTime",
   [File],
   c_uint),

  ("clang_getIBOutletCollectionType",
   [Cursor],
   Type,
   Type.from_result),

  ("clang_getIncludedFile",
   [Cursor],
   File,
   File.from_cursor_result),

  ("clang_getInclusions",
   [TranslationUnit, callbacks['translation_unit_includes'], py_object]),

  ("clang_getInstantiationLocation",
   [SourceLocation, POINTER(c_object_p), POINTER(c_uint), POINTER(c_uint),
    POINTER(c_uint)]),

  ("clang_getLocation",
   [TranslationUnit, File, c_uint, c_uint],
   SourceLocation),

  ("clang_getLocationForOffset",
   [TranslationUnit, File, c_uint],
   SourceLocation),

  ("clang_getNullCursor",
   None,
   Cursor),

  ("clang_getNumArgTypes",
   [Type],
   c_uint),

  ("clang_getNumCompletionChunks",
   [c_void_p],
   c_int),

  ("clang_getNumDiagnostics",
   [c_object_p],
   c_uint),

  ("clang_getNumElements",
   [Type],
   c_longlong),

  ("clang_getNumOverloadedDecls",
   [Cursor],
   c_uint),

  ("clang_getOverloadedDecl",
   [Cursor, c_uint],
   Cursor,
   Cursor.from_cursor_result),

  ("clang_getPointeeType",
   [Type],
   Type,
   Type.from_result),

  ("clang_getRange",
   [SourceLocation, SourceLocation],
   SourceRange),

  ("clang_getRangeEnd",
   [SourceRange],
   SourceLocation),

  ("clang_getRangeStart",
   [SourceRange],
   SourceLocation),

  ("clang_getResultType",
   [Type],
   Type,
   Type.from_result),

  ("clang_getSpecializedCursorTemplate",
   [Cursor],
   Cursor,
   Cursor.from_cursor_result),

  ("clang_getTemplateCursorKind",
   [Cursor],
   c_uint),

  ("clang_getTokenExtent",
   [TranslationUnit, Token],
   SourceRange),

  ("clang_getTokenKind",
   [Token],
   c_uint),

  ("clang_getTokenLocation",
   [TranslationUnit, Token],
   SourceLocation),

  ("clang_getTokenSpelling",
   [TranslationUnit, Token],
   _CXString,
   _CXString.from_result),

  ("clang_getTranslationUnitCursor",
   [TranslationUnit],
   Cursor,
   Cursor.from_result),

  ("clang_getTranslationUnitSpelling",
   [TranslationUnit],
   _CXString,
   _CXString.from_result),

  ("clang_getTUResourceUsageName",
   [c_uint],
   c_char_p),

  ("clang_getTypeDeclaration",
   [Type],
   Cursor,
   Cursor.from_result),

  ("clang_getTypedefDeclUnderlyingType",
   [Cursor],
   Type,
   Type.from_result),

  ("clang_getTypeKindSpelling",
   [c_uint],
   _CXString,
   _CXString.from_result),

  ("clang_hashCursor",
   [Cursor],
   c_uint),

  ("clang_isAttribute",
   [CursorKind],
   bool),

  ("clang_isConstQualifiedType",
   [Type],
   bool),

  ("clang_isCursorDefinition",
   [Cursor],
   bool),

  ("clang_isDeclaration",
   [CursorKind],
   bool),

  ("clang_isExpression",
   [CursorKind],
   bool),

  ("clang_isFileMultipleIncludeGuarded",
   [TranslationUnit, File],
   bool),

  ("clang_isFunctionTypeVariadic",
   [Type],
   bool),

  ("clang_isInvalid",
   [CursorKind],
   bool),

  ("clang_isPODType",
   [Type],
   bool),

  ("clang_isPreprocessing",
   [CursorKind],
   bool),

  ("clang_isReference",
   [CursorKind],
   bool),

  ("clang_isRestrictQualifiedType",
   [Type],
   bool),

  ("clang_isStatement",
   [CursorKind],
   bool),

  ("clang_isTranslationUnit",
   [CursorKind],
   bool),

  ("clang_isUnexposed",
   [CursorKind],
   bool),

  ("clang_isVirtualBase",
   [Cursor],
   bool),

  ("clang_isVolatileQualifiedType",
   [Type],
   bool),

  ("clang_parseTranslationUnit",
   [Index, c_char_p, c_void_p, c_int, c_void_p, c_int, c_int],
   c_object_p),

  ("clang_reparseTranslationUnit",
   [TranslationUnit, c_int, c_void_p, c_int],
   c_int),

  ("clang_saveTranslationUnit",
   [TranslationUnit, c_char_p, c_uint],
   c_int),

  ("clang_tokenize",
   [TranslationUnit, SourceRange, POINTER(POINTER(Token)), POINTER(c_uint)]),

  ("clang_visitChildren",
   [Cursor, callbacks['cursor_visit'], py_object],
   c_uint),

  ("clang_Cursor_getNumArguments",
   [Cursor],
   c_int),

  ("clang_Cursor_getArgument",
   [Cursor, c_uint],
   Cursor,
   Cursor.from_result),

  ("clang_Cursor_isBitField",
   [Cursor],
   bool),

  ("clang_Type_getAlignOf",
   [Type],
   c_longlong),

  ("clang_Type_getOffsetOf",
   [Type, c_char_p],
   c_longlong),

  ("clang_Type_getSizeOf",
   [Type],
   c_longlong),
]

class LibclangError(Exception):
    def __init__(self, message):
        self.m = message

    def __str__(self):
        return self.m

def register_function(lib, item, ignore_errors):
    # A function may not exist, if these bindings are used with an older or
    # incompatible version of libclang.so.
    try:
        func = getattr(lib, item[0])
    except AttributeError as e:
        msg = str(e) + ". Please ensure that your python bindings are "\
                       "compatible with your libclang.so version."
        if ignore_errors:
            return
        raise LibclangError(msg)

    if len(item) >= 2:
        func.argtypes = item[1]

    if len(item) >= 3:
        func.restype = item[2]

    if len(item) == 4:
        func.errcheck = item[3]

def register_functions(lib, ignore_errors):
    """Register function prototypes with a libclang library instance.

    This must be called as part of library instantiation so Python knows how
    to call out to the shared library.
    """

    def register(item):
        return register_function(lib, item, ignore_errors)

    map(register, functionList)

class Config:
    library_path = None
    library_file = None
    compatibility_check = True
    loaded = False

    @staticmethod
    def set_library_path(path):
        """Set the path in which to search for libclang"""
        if Config.loaded:
            raise Exception("library path must be set before before using " \
                            "any other functionalities in libclang.")

        Config.library_path = path

    @staticmethod
    def set_library_file(filename):
        """Set the exact location of libclang"""
        if Config.loaded:
            raise Exception("library file must be set before before using " \
                            "any other functionalities in libclang.")

        Config.library_file = filename

    @staticmethod
    def set_compatibility_check(check_status):
        """ Perform compatibility check when loading libclang

        The python bindings are only tested and evaluated with the version of
        libclang they are provided with. To ensure correct behavior a (limited)
        compatibility check is performed when loading the bindings. This check
        will throw an exception, as soon as it fails.

        In case these bindings are used with an older version of libclang, parts
        that have been stable between releases may still work. Users of the
        python bindings can disable the compatibility check. This will cause
        the python bindings to load, even though they are written for a newer
        version of libclang. Failures now arise if unsupported or incompatible
        features are accessed. The user is required to test himself if the
        features he is using are available and compatible between different
        libclang versions.
        """
        if Config.loaded:
            raise Exception("compatibility_check must be set before before " \
                            "using any other functionalities in libclang.")

        Config.compatibility_check = check_status

    @CachedProperty
    def lib(self):
        lib = self.get_cindex_library()
        register_functions(lib, not Config.compatibility_check)
        Config.loaded = True
        return lib

    def get_filename(self):
        if Config.library_file:
            return Config.library_file

        import platform
        name = platform.system()

        if name == 'Darwin':
            file = 'libclang.dylib'
        elif name == 'Windows':
            file = 'libclang.dll'
        else:
            file = 'libclang.so'

        if Config.library_path:
            file = Config.library_path + '/' + file

        return file

    def get_cindex_library(self):
        try:
            library = cdll.LoadLibrary(self.get_filename())
        except OSError as e:
            msg = str(e) + ". To provide a path to libclang use " \
                           "Config.set_library_path() or " \
                           "Config.set_library_file()."
            raise LibclangError(msg)

        return library

    def function_exists(self, name):
        try:
            getattr(self.lib, name)
        except AttributeError:
            return False

        return True

def register_enumerations():
    for name, value in clang.enumerations.TokenKinds:
        TokenKind.register(value, name)

conf = Config()
register_enumerations()

__all__ = [
    'Config',
    'CodeCompletionResults',
    'CompilationDatabase',
    'CompileCommands',
    'CompileCommand',
    'CursorKind',
    'Cursor',
    'Diagnostic',
    'File',
    'FixIt',
    'Index',
    'SourceLocation',
    'SourceRange',
    'TokenKind',
    'Token',
    'TranslationUnitLoadError',
    'TranslationUnit',
    'TypeKind',
    'Type',
]