glib/gitypelib-internal.h

/* GObject introspection: struct definitions for the binary
 * typelib format, validation
 *
 * Copyright (C) 2005 Matthias Clasen
 * Copyright (C) 2008,2009 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef __G_TYPELIB_H__
#define __G_TYPELIB_H__

#include <gmodule.h>
#include "girepository.h"

G_BEGIN_DECLS

/**
 * SECTION:gtypelib
 * @short_description: Layout and accessors for typelib
 * @stability: Stable
 *
 * The "typelib" is a binary, readonly, memory-mappable database
 * containing reflective information about a GObject library.
 *
 * The format of GObject typelib is strongly influenced by the Mozilla XPCOM
 * format.
 *
 * Some of the differences to XPCOM include:
 * - Type information is stored not quite as compactly (XPCOM stores it inline
 * in function descriptions in variable-sized blobs of 1 to n bytes. We store
 * 16 bits of type information for each parameter, which is enough to encode
 * simple types inline. Complex (e.g. recursive) types are stored out of line
 * in a separate list of types.
 * - String and complex type data is stored outside of typelib entry blobs,
 * references are stored as offsets relative to the start of the typelib.
 * One possibility is to store the strings and types in a pools at the end
 * of the typelib.
 *
 * The typelib has the following general format.
 *
 * typelib ::= header, directory, blobs, attributes, attributedata
 *
 * directory ::= list of entries
 *
 * entry ::= blob type, name, namespace, offset
 * blob ::= function|callback|struct|boxed|enum|flags|object|interface|constant|errordomain|union
 * attributes ::= list of attributes, sorted by offset
 * attribute ::= offset, key, value
 * attributedata ::= string data for attributes
 *
 * Details
 *
 * We describe the fragments that make up the typelib in the form of C structs
 * (although some fall short of being valid C structs since they contain multiple
 * flexible arrays).
 */

/*
TYPELIB HISTORY
-----
Version 1.0
- Rename class_struct to gtype_struct, add to interfaces

Changes since 0.9:
- Add padding to structures

Changes since 0.8:
- Add class struct concept to ObjectBlob
- Add is_class_struct bit to StructBlob

Changes since 0.7:
- Add dependencies

Changes since 0.6:
- rename metadata to typelib, to follow xpcom terminology

Changes since 0.5:
- basic type cleanup:
  + remove GString
  + add [u]int, [u]long, [s]size_t
  + rename string to utf8, add filename
- allow blob_type to be zero for non-local entries

Changes since 0.4:
- add a UnionBlob

Changes since 0.3:
- drop short_name for ValueBlob

Changes since 0.2:
- make inline types 4 bytes after all, remove header->types and allow
  types to appear anywhere
- allow error domains in the directory

Changes since 0.1:

- drop comments about _GOBJ_METADATA
- drop string pool, strings can appear anywhere
- use 'blob' as collective name for the various blob types
- rename 'type' field in blobs to 'blob_type'
- rename 'type_name' and 'type_init' fields to 'gtype_name', 'gtype_init'
- shrink directory entries to 12 bytes
- merge struct and boxed blobs
- split interface blobs into enum, object and interface blobs
- add an 'unregistered' flag to struct and enum blobs
- add a 'wraps_vfunc' flag to function blobs and link them to
  the vfuncs they wrap
- restrict value blobs to only occur inside enums and flags again
- add constant blobs, allow them toplevel, in interfaces and in objects
- rename 'receiver_owns_value' and 'receiver_owns_container' to
  'transfer_ownership' and 'transfer_container_ownership'
- add a 'struct_offset' field to virtual function and field blobs
- add 'dipper' and 'optional' flags to arg blobs
- add a 'true_stops_emit' flag to signal blobs
- add variable blob sizes to header
- store offsets to signature blobs instead of including them directly
- change the type offset to be measured in words rather than bytes
*/

/**
 * G_IR_MAGIC:
 *
 * Identifying prefix for the typelib.  This was inspired by XPCOM,
 * which in turn borrowed from PNG.
 */
#define G_IR_MAGIC "GOBJ\nMETADATA\r\n\032"

/**
 * GTypelibBlobType:
 * @BLOB_TYPE_INVALID: Should not appear in code
 * @BLOB_TYPE_FUNCTION: A #FunctionBlob
 * @BLOB_TYPE_CALLBACK: A #CallbackBlob
 * @BLOB_TYPE_STRUCT: A #StructBlob
 * @BLOB_TYPE_BOXED: Can be either a #StructBlob or #UnionBlob
 * @BLOB_TYPE_ENUM: An #EnumBlob
 * @BLOB_TYPE_FLAGS: An #EnumBlob
 * @BLOB_TYPE_OBJECT: An #ObjectBlob
 * @BLOB_TYPE_INTERFACE: An #InterfaceBlob
 * @BLOB_TYPE_CONSTANT: A #ConstantBlob
 * @BLOB_TYPE_ERROR_DOMAIN: A #ErrorDomainBlob
 * @BLOB_TYPE_UNION: A #UnionBlob
 *
 * The integral value of this enumeration appears in each "Blob"
 * component of a typelib to identify its type.
 */
typedef enum {
  BLOB_TYPE_INVALID,
  BLOB_TYPE_FUNCTION,
  BLOB_TYPE_CALLBACK,
  BLOB_TYPE_STRUCT,
  BLOB_TYPE_BOXED,
  BLOB_TYPE_ENUM,
  BLOB_TYPE_FLAGS,
  BLOB_TYPE_OBJECT,
  BLOB_TYPE_INTERFACE,
  BLOB_TYPE_CONSTANT,
  BLOB_TYPE_ERROR_DOMAIN,
  BLOB_TYPE_UNION
} GTypelibBlobType;

#define BLOB_IS_REGISTERED_TYPE(blob)               \
        ((blob)->blob_type == BLOB_TYPE_STRUCT ||   \
         (blob)->blob_type == BLOB_TYPE_UNION  ||   \
         (blob)->blob_type == BLOB_TYPE_ENUM   ||   \
         (blob)->blob_type == BLOB_TYPE_OBJECT ||   \
         (blob)->blob_type == BLOB_TYPE_INTERFACE)

/**
 * Header:
 * @magic: See #G_IR_MAGIC.
 * @major_version: The version of the typelib format. Minor version changes indicate
 * compatible changes and should still allow the typelib to be parsed
 * by a parser designed for the same major_version.
 * @minor_version: See major_version.
 * @n_entries: The number of entries in the directory.
 * @n_local_entries: The number of entries referring to blobs in this typelib. The
 * local entries must occur before the unresolved entries.
 * @directory: Offset of the directory in the typelib.
 * @n_attributes: Number of attribute blocks
 * @attributes: Offset of the list of attributes in the typelib.
 * @dependencies: Offset of a single string, which is the list of
 * dependencies, separated by the '|' character.  The
 * dependencies are required in order to avoid having programs
 * consuming a typelib check for an "Unresolved" type return
 * from every API call.
 * @size: The size in bytes of the typelib.
 * @namespace: Offset of the namespace string in the typelib.
 * @nsversion: Offset of the namespace version string in the typelib.
 * @shared_library: This field is the set of shared libraries associated
 * with the typelib.  The entries are separated by the '|' (pipe) character.
 * @c_prefix: The prefix for the function names of the library
 * @entry_blob_size: The sizes of fixed-size blobs. Recording this information here
 * allows to write parser which continue to work if the format is
 * extended by adding new fields to the end of the fixed-size blobs.
 * @function_blob_size: See above.
 * @callback_blob_size: See above.
 * @signal_blob_size: See above.
 * @vfunc_blob_size: See above.
 * @arg_blob_size: See above.
 * @property_blob_size: See above.
 * @field_blob_size: See above.
 * @value_blob_size: See above.
 * @attribute_blob_size: See above.
 * @constant_blob_size: See above.
 * @object_blob_size: See above.
 * @union_blob_size: See above.
 * @signature_blob_size: See above.
 * @enum_blob_size: See above.
 * @struct_blob_size: See above.
 * @error_domain_blob_size: See above.
 * @interface_blob_size: For variable-size blobs, the size of the struct up to the first
 * flexible array member. Recording this information here allows to
 * write parser which continue to work if the format is extended by
 * adding new fields before the first flexible array member in
 * variable-size blobs.
 *
 * The header structure appears exactly once at the beginning of a typelib.  It is a
 * collection of meta-information, such as the number of entries and dependencies.
 */
typedef struct {
  gchar   magic[16];
  guint8  major_version;
  guint8  minor_version;
  /* <private> */
  guint16 reserved;
  /* <public> */
  guint16 n_entries;
  guint16 n_local_entries;
  guint32 directory;
  guint32 n_attributes;
  guint32 attributes;

  guint32 dependencies;

  guint32 size;
  guint32 namespace;
  guint32 nsversion;
  guint32 shared_library;
  guint32 c_prefix;

  guint16 entry_blob_size;
  guint16 function_blob_size;
  guint16 callback_blob_size;
  guint16 signal_blob_size;
  guint16 vfunc_blob_size;
  guint16 arg_blob_size;
  guint16 property_blob_size;
  guint16 field_blob_size;
  guint16 value_blob_size;
  guint16 attribute_blob_size;
  guint16 constant_blob_size;
  guint16 error_domain_blob_size;

  guint16 signature_blob_size;
  guint16 enum_blob_size;
  guint16 struct_blob_size;
  guint16 object_blob_size;
  guint16 interface_blob_size;
  guint16 union_blob_size;

  /* <private> */
  guint16 padding[7];
} Header;

/**
 * DirEntry:
 * @blob_type: A #GTypelibBlobType
 * @local: Whether this entry refers to a blob in this typelib.
 * @name: The name of the entry.
 * @offset:   If is_local is set, this is the offset of the blob in the typelib.
 * Otherwise, it is the offset of the namespace in which the blob has
 * to be looked up by name.
 *
 * References to directory entries are stored as 1-based 16-bit indexes.
 *
 * All blobs pointed to by a directory entry start with the same layout for
 * the first 8 bytes (the reserved flags may be used by some blob types)
 */
typedef struct {
  guint16 blob_type;

  guint16 local    : 1;
  /* <private> */
  guint16 reserved :15;
  /* <public> */
  guint32 name;
  guint32 offset;
} DirEntry;

/**
 * SimpleTypeBlob:
 * @is_pointer: Indicates whether the type is passed by reference.
 * @tag: A #GITypeTag
 * @offset:  Offset relative to header->types that points to a TypeBlob.
 * Unlike other offsets, this is in words (ie 32bit units) rather
 * than bytes.
 *
 * The SimpleTypeBlob is the general purpose "reference to a type" construct, used
 * in method parameters, returns, callback definitions, fields, constants, etc.
 * It's actually just a 32 bit integer which you can see from the union definition.
 * This is for efficiency reasons, since there are so many references to types.
 *
 * SimpleTypeBlob is divided into two cases; first, if "reserved" and "reserved2", the
 * type tag for a basic type is embedded in the "tag" bits.  This allows e.g.
 * GI_TYPE_TAG_UTF8, GI_TYPE_TAG_INT and the like to be embedded directly without
 * taking up extra space.
 *
 * References to "interfaces" (objects, interfaces) are more complicated;  In this case,
 * the integer is actually an offset into the directory (see above).  Because the header
 * is larger than 2^8=256 bits, all offsets will have one of the upper 24 bits set.
 */
typedef union
{
  struct
  {
    /* <private> */
    guint reserved   : 8;
    guint reserved2  :16;
    /* <public> */
    guint pointer    : 1;
    /* <private> */
    guint reserved3  : 2;
    /* <public> */
    guint tag        : 5;
  } flags;
  guint32    offset;
} SimpleTypeBlob;

/**
 * ArgBlob:
 * @name: A suggested name for the parameter.
 * @in: The parameter is an input to the function
 * @out: The parameter is used to return an output of the function.
 * Parameters can be both in and out. Out parameters implicitly
 * add another level of indirection to the parameter type. Ie if
 * the type is uint32 in an out parameter, the function actually
 * takes an uint32*.
 * @caller_allocates: The parameter is a pointer to a struct or object that will
 * receive an output of the function.
 * @allow_none: Only meaningful for types which are passed as pointers.
 * For an in parameter, indicates if it is ok to pass NULL in, for
 * an out parameter, whether it may return NULL. Note that NULL is a
 * valid GList and GSList value, thus allow_none will normally be set
 * for parameters of these types.
 * @optional: For an out parameter, indicates that NULL may be passed in
 * if the value is not needed.
 * @transfer_ownership: For an in parameter, indicates that the function takes over
 * ownership of the parameter value. For an out parameter, it
 * indicates that the caller is responsible for freeing the return
 * value.
 * @transfer_container_ownership: For container types, indicates that the
 * ownership of the container,  but not of its contents is transferred. This is typically the case
 * for out parameters returning lists of statically allocated things.
 * @return_value: The parameter should be considered the return value of the function.
 * Only out parameters can be marked as return value, and there can be
 * at most one per function call. If an out parameter is marked as
 * return value, the actual return value of the function should be
 * either void or a boolean indicating the success of the call.
 * @scope: A #GIScopeType. If the parameter is of a callback type, this denotes the scope
 * of the user_data and the callback function pointer itself
 * (for languages that emit code at run-time).
 * @closure: Index of the closure (user_data) parameter associated with the callback,
 * or -1.
 * @destroy: Index of the destroy notfication callback parameter associated with
 * the callback, or -1.
 * @arg_type: Describes the type of the parameter. See details below.
 *
 * Types are specified by four bytes. If the three high bytes are zero,
 * the low byte describes a basic type, otherwise the 32bit number is an
 * offset which points to a TypeBlob.
 */
typedef struct {
  guint32        name;

  guint          in                           : 1;
  guint          out                          : 1;
  guint          caller_allocates             : 1;
  guint          allow_none                   : 1;
  guint          optional                     : 1;
  guint          transfer_ownership           : 1;
  guint          transfer_container_ownership : 1;
  guint          return_value                 : 1;
  guint          scope                        : 3;
  /* <private> */
  guint          reserved                     :21;

  gint8        closure;
  gint8        destroy;

  SimpleTypeBlob arg_type;
} ArgBlob;

/**
 * SignatureBlob:
 * @return_type: Describes the type of the return value. See details below.
 * @may_return_null: Only relevant for pointer types. Indicates whether the caller
 * must expect NULL as a return value.
 * @caller_owns_return_value: If set, the caller is responsible for freeing the return value
 * if it is no longer needed.
 * @caller_owns_return_container: This flag is only relevant if the return type is a container type.
 * If the flag is set, the caller is resonsible for freeing the
 * container, but not its contents.
 * @n_arguments: The number of arguments that this function expects, also the length
 * of the array of ArgBlobs.
 * @arguments: An array of ArgBlob for the arguments of the function.
 */
typedef struct {
  SimpleTypeBlob return_type;

  guint16        may_return_null              : 1;
  guint16        caller_owns_return_value     : 1;
  guint16        caller_owns_return_container : 1;
  guint16        reserved                     :13;

  guint16        n_arguments;

  ArgBlob        arguments[];
} SignatureBlob;

/**
 * CommonBlob:
 * @blob_type: A #GTypelibBlobType
 * @deprecated: Whether the blob is deprecated.
 * @name: The name of the blob.
 *
 * The #CommonBlob is shared between #FunctionBlob,
 * #CallbackBlob, #SignalBlob.
 */
typedef struct {
  guint16 blob_type;  /* 1 */

  guint16 deprecated : 1;
  /* <private> */
  guint16 reserved   :15;
  /* <public> */
  guint32 name;
} CommonBlob;

/**
 * FunctionBlob:
 * @blob_Type: #BLOB_TYPE_FUNCTION
 * @symbol:   The symbol which can be used to obtain the function pointer with
 * dlsym().
 * @deprecated: The function is deprecated.
 * @setter: The function is a setter for a property. Language bindings may
 * prefer to not bind individual setters and rely on the generic
 * g_object_set().
 * @getter: The function is a getter for a property. Language bindings may
 * prefer to not bind individual getters and rely on the generic
 * g_object_get().
 * @constructor:The function acts as a constructor for the object it is contained
 * in.
 * @wraps_vfunc: The function is a simple wrapper for a virtual function.
 * @index: Index of the property that this function is a setter or getter of
 * in the array of properties of the containing interface, or index
 * of the virtual function that this function wraps.
 * @signature: Offset of the SignatureBlob describing the parameter types and the
 * return value type.
 * @is_static: The function is a "static method"; in other words it's a pure
 * function whose name is conceptually scoped to the object.
 */
typedef struct {
  guint16 blob_type;  /* 1 */

  guint16 deprecated  : 1;
  guint16 setter      : 1;
  guint16 getter      : 1;
  guint16 constructor : 1;
  guint16 wraps_vfunc : 1;
  guint16 throws      : 1;
  guint16 index       :10;
  /* Note the bits above need to match CommonBlob
   * and are thus exhausted, extend things using
   * the reserved block below. */

  guint32 name;
  guint32 symbol;
  guint32 signature;

  guint16 is_static   : 1;
  guint16 reserved    : 15;
  guint16 reserved2   : 16;
} FunctionBlob;

/**
 * CallbackBlob:
 * @signature: Offset of the #SignatureBlob describing the parameter types and the
 * return value type.
 */
typedef struct {
  guint16 blob_type;  /* 2 */

  guint16 deprecated : 1;
  /* <private> */
  guint16 reserved   :15;
  /* <public> */
  guint32 name;
  guint32 signature;
} CallbackBlob;

/**
 * InterfaceTypeBlob:
 * @pointer: Whether this type represents an indirection
 * @tag: A #GITypeTag
 * @interface: Index of the directory entry for the interface.
 *
 * If the interface is an enum of flags type, is_pointer is 0, otherwise it is 1.
 */
typedef struct {
  guint8  pointer  :1;
  /* <private> */
  guint8  reserved :2;
  /* <public> */
  guint8  tag      :5;
  /* <private> */
  guint8  reserved2;
  /* <public> */
  guint16 interface;
} InterfaceTypeBlob;

/**
 * ArrayTypeBlob:
 * @zero_terminated: Indicates that the array must be terminated by a suitable #NULL
 * value.
 * @has_length: Indicates that length points to a parameter specifying the length
 * of the array. If both has_length and zero_terminated are set, the
 * convention is to pass -1 for the length if the array is
 * zero-terminated.
 * @has_size: Indicates that size is the fixed size of the array.
 * @array_type: Indicates whether this is a C array, GArray, GPtrArray, or
 * GByteArray. If something other than a C array, the length and element size
 * are implicit in the structure.
 * @length: The index of the parameter which is used to pass the length of the
 * array. The parameter must be an integer type and have the same
 * direction as this one.
 * @size: The fixed size of the array.
 * @type: The type of the array elements.
 * Arrays are passed by reference, thus is_pointer is always 1.
 */
typedef struct {
  guint16 pointer         :1;
  guint16 reserved        :2;
  guint16 tag             :5;

  guint16 zero_terminated :1;
  guint16 has_length      :1;
  guint16 has_size        :1;
  guint16 array_type      :2;
  guint16 reserved2       :3;

  union {
    guint16 length;
    guint16 size;
  } dimensions;

  SimpleTypeBlob type;
} ArrayTypeBlob;

/**
 * ParamTypeBlob:
 * @n_types: The number of parameter types to follow.
 * @type: Describes the type of the list elements.
 *
 */
typedef struct {
  guint8	 pointer  :1;
  guint8	 reserved :2;
  guint8	 tag      :5;

  guint8	 reserved2;
  guint16	 n_types;

  SimpleTypeBlob type[];
} ParamTypeBlob;

/**
 * ErrorTypeBlob:
 * @n_domains: The number of domains to follow
 * @domains:  Indices of the directory entries for the error domains
 */
typedef struct {
  guint8  pointer  :1;
  guint8  reserved :2;
  guint8  tag      :5;

  guint8  reserved2;
  guint16 n_domains;

  guint16 domains[];
}  ErrorTypeBlob;

/**
 * ErrorDomainBlob:
 * @get_quark: The symbol name of the function which must be called to obtain the
 * GQuark for the error domain.
 * @error_codes: Index of the InterfaceBlob describing the enumeration which lists
 * the possible error codes.
 */
typedef struct {
  guint16 blob_type;  /* 10 */

  guint16 deprecated : 1;
  guint16 reserved   :15;

  guint32 name;

  guint32 get_quark;
  guint16 error_codes;
  guint16 reserved2;
} ErrorDomainBlob;

/**
 * ValueBlob:
 * @deprecated: Whether this value is deprecated
 * @value: The numerical value
 * @name: Name of blob
 *
 * Values commonly occur in enums and flags.
 */
typedef struct {
  guint32 deprecated : 1;
  /* <private> */
  guint32 reserved   :31;
  /* <public> */
  guint32 name;
  gint32 value;
} ValueBlob;

/**
 * FieldBlob:
 * @name: The name of the field.
 * @readable:
 * @writable: How the field may be accessed.
 * @has_embedded_type: An anonymous type follows the FieldBlob.
 * @bits: If this field is part of a bitfield, the number of bits which it
 * uses, otherwise 0.
 * @struct_offset:
 * The offset of the field in the struct. The value 0xFFFF indicates
 * that the struct offset is unknown.
 * @type: The type of the field.
 */
typedef struct {
  guint32        name;

  guint8         readable :1;
  guint8         writable :1;
  guint8         has_embedded_type :1;
  guint8         reserved :5;
  guint8         bits;

  guint16        struct_offset;

  guint32        reserved2;

  SimpleTypeBlob type;
} FieldBlob;

/**
 * RegisteredTypeBlob:
 * @gtype_name: The name under which the type is registered with GType.
 * @gtype_init: The symbol name of the get_type() function which registers the type.
 */
typedef struct {
  guint16 blob_type;
  guint16 deprecated   : 1;
  guint16 unregistered : 1;
  guint16 reserved :14;
  guint32 name;

  guint32 gtype_name;
  guint32 gtype_init;
} RegisteredTypeBlob;

/**
 * StructBlob:
 * @blob_type: #BLOB_TYPE_STRUCT
 * @deprecated: Whether this structure is deprecated
 * @unregistered: If this is set, the type is not registered with GType.
 * @alignment: The byte boundary that the struct is aligned to in memory
 * @is_gtype_struct: Whether this structure is the class or interface layout for a GObject
 * @foreign: If the type is foreign, eg if it's expected to be overridden by
 * a native language binding instead of relying of introspected bindings.
 * @size: The size of the struct in bytes.
 * @gtype_name: String name of the associated #GType
 * @gtype_init: String naming the symbol which gets the runtime #GType
 * @n_fields:
 * @fields: An array of n_fields FieldBlobs.
 * should be considered as methods of the struct.
 */
typedef struct {
  guint16   blob_type;

  guint16   deprecated   : 1;
  guint16   unregistered : 1;
  guint16   is_gtype_struct : 1;
  guint16   alignment    : 6;
  guint16   foreign      : 1;
  guint16   reserved     : 6;

  guint32   name;

  guint32   gtype_name;
  guint32   gtype_init;

  guint32   size;

  guint16   n_fields;
  guint16   n_methods;

  guint32   reserved2;
  guint32   reserved3;

#if 0
  /* variable-length parts of the blob */
  FieldBlob    fields[];
  FunctionBlob methods[];
#endif
} StructBlob;

/**
 * UnionBlob:
 * @unregistered: If this is set, the type is not registered with GType.
 * @discriminated: Is set if the union is discriminated
 * @alignment: The byte boundary that the union is aligned to in memory
 * @size: The size of the union in bytes.
 * @gtype_name: String name of the associated #GType
 * @gtype_init: String naming the symbol which gets the runtime #GType
 * @n_fields: Length of the arrays
 * @discriminator_offset: Offset from the beginning of the union where the
 * discriminator of a discriminated union is located.
 * The value 0xFFFF indicates that the discriminator offset
 * is unknown.
 * @discriminator_type: Type of the discriminator
 * @fields: Array of FieldBlobs describing the alternative branches of the union
 */
typedef struct {
  guint16      blob_type;
  guint16      deprecated    : 1;
  guint16      unregistered  : 1;
  guint16      discriminated : 1;
  guint16      alignment     : 6;
  guint16      reserved      : 7;
  guint32      name;

  guint32      gtype_name;
  guint32      gtype_init;

  guint32      size;

  guint16      n_fields;
  guint16      n_functions;

  guint32      reserved2;
  guint32      reserved3;

  gint32       discriminator_offset;
  SimpleTypeBlob discriminator_type;

#if 0
  FieldBlob    fields[];
  FunctionBlob functions[];
  ConstantBlob discriminator_values[]
#endif
} UnionBlob;

/**
 * EnumBlob:
 * @unregistered: If this is set, the type is not registered with GType.
 * @storage_type: The tag of the type used for the enum in the C ABI
 * (will be a signed or unsigned integral type)
 * @gtype_name: String name of the associated #GType
 * @gtype_init: String naming the symbol which gets the runtime #GType
 * @n_values: The lengths of the values arrays.
 * @values: Describes the enum values.
 */
typedef struct {
  guint16   blob_type;

  guint16   deprecated   : 1;
  guint16   unregistered : 1;
  guint16   storage_type : 5;
  guint16   reserved     : 9;

  guint32   name;

  guint32   gtype_name;
  guint32   gtype_init;

  guint16   n_values;
  guint16   reserved2;

  guint32   reserved3;

  ValueBlob values[];
} EnumBlob;

/**
 * PropertyBlob:
 * @name:     The name of the property.
 * @readable:
 * @writable:
 * @construct:
 * @construct_only: The ParamFlags used when registering the property.
 * @type: Describes the type of the property.
 */
typedef struct {
  guint32        name;

  guint32        deprecated     : 1;
  guint32        readable       : 1;
  guint32        writable       : 1;
  guint32        construct      : 1;
  guint32        construct_only : 1;
  guint32        reserved       :27;

  guint32        reserved2;

  SimpleTypeBlob type;
} PropertyBlob;

/**
 * SignalBlob:
 * @name: The name of the signal.
 * @run_first:
 * @run_last:
 * @run_cleanup:
 * @no_recurse:
 * @detailed:
 * @action:
 * @no_hooks: The flags used when registering the signal.
 * @has_class_closure: Set if the signal has a class closure.
 * @true_stops_emit: Whether the signal has true-stops-emit semantics
 * @class_closure: The index of the class closure in the list of virtual functions
 * of the object or interface on which the signal is defined.
 * @signature: Offset of the SignatureBlob describing the parameter types and the
 * return value type.
 */
typedef struct {
  guint16 deprecated        : 1;
  guint16 run_first         : 1;
  guint16 run_last          : 1;
  guint16 run_cleanup       : 1;
  guint16 no_recurse        : 1;
  guint16 detailed          : 1;
  guint16 action            : 1;
  guint16 no_hooks          : 1;
  guint16 has_class_closure : 1;
  guint16 true_stops_emit   : 1;
  guint16 reserved          : 6;

  guint16 class_closure;

  guint32 name;

  guint32 reserved2;

  guint32 signature;
} SignalBlob;

/**
 * VFuncBlob:
 * @name: The name of the virtual function.
 * @must_chain_up: If set, every implementation of this virtual function must
 * chain up to the implementation of the parent class.
 * @must_be_implemented: If set, every derived class must override this virtual function.
 * @must_not_be_implemented: If set, derived class must not override this virtual function.
 * @class_closure: Set if this virtual function is the class closure of a signal.
 * @signal: The index of the signal in the list of signals of the object or
 * interface to which this virtual function belongs.
 * @struct_offset: The offset of the function pointer in the class struct. The value
 * 0xFFFF indicates that the struct offset is unknown.
 * @invoker: If a method invoker for this virtual exists, this is the offset in the
 * class structure of the method.  If no method is known, this value will be 0x3ff.
 * @signature:
 * Offset of the SignatureBlob describing the parameter types and the
 * return value type.
 */
typedef struct {
  guint32 name;

  guint16 must_chain_up           : 1;
  guint16 must_be_implemented     : 1;
  guint16 must_not_be_implemented : 1;
  guint16 class_closure           : 1;
  guint16 reserved                :12;
  guint16 signal;

  guint16 struct_offset;
  guint16 invoker : 10; /* Number of bits matches @index in FunctionBlob */
  guint16 reserved2 : 6;

  guint32 reserved3;
  guint32 signature;
} VFuncBlob;

/**
 * ObjectBlob:
 * @blob_type: #BLOB_TYPE_OBJECT
 * @gtype_name: String name of the associated #GType
 * @gtype_init: String naming the symbol which gets the runtime #GType
 * @parent: The directory index of the parent type. This is only set for
 * objects. If an object does not have a parent, it is zero.
 * @n_interfaces:
 * @n_fields:
 * @n_properties:
 * @n_methods:
 * @n_signals:
 * @n_vfuncs:
 * @n_constants: The lengths of the arrays.Up to 16bits of padding may be inserted
 * between the arrays to ensure that they start on a 32bit boundary.
 * @interfaces: An array of indices of directory entries for the implemented
 * interfaces.
 * @fields: Describes the fields.
 * @methods: Describes the methods, constructors, setters and getters.
 * @properties: Describes the properties.
 * @signals: Describes the signals.
 * @vfuncs: Describes the virtual functions.
 * @constants: Describes the constants.
 */
typedef struct {
  guint16   blob_type;  /* 7 */
  guint16   deprecated   : 1;
  guint16   abstract     : 1;
  guint16   reserved     :14;
  guint32   name;

  guint32   gtype_name;
  guint32   gtype_init;

  guint16   parent;
  guint16   gtype_struct;

  guint16   n_interfaces;
  guint16   n_fields;
  guint16   n_properties;
  guint16   n_methods;
  guint16   n_signals;
  guint16   n_vfuncs;
  guint16   n_constants;
  guint16   reserved2;

  guint32   reserved3;
  guint32   reserved4;

  guint16   interfaces[];

#if 0
  /* variable-length parts of the blob */
  FieldBlob           fields[];
  PropertyBlob        properties[];
  FunctionBlob        methods[];
  SignalBlob          signals[];
  VFuncBlob           vfuncs[];
  ConstantBlob        constants[];
#endif
} ObjectBlob;

/**
 * InterfaceBlob:
 * @gtype_struct: Name of the interface "class" C structure
 * @n_prerequisites: Number of prerequisites
 * @n_properties: Number of properties
 * @n_methods: Number of methods
 * @n_signals: Number of signals
 * @n_vfuncs: Number of virtual functions
 * @n_constants: The lengths of the arrays.
 * Up to 16bits of padding may be inserted between the arrays to ensure that they
 * start on a 32bit boundary.
 * @prerequisites: An array of indices of directory entries for required interfaces.
 * @methods: Describes the methods, constructors, setters and getters.
 * @properties: Describes the properties.
 * @signals:  Describes the signals.
 * @vfuncs: Describes the virtual functions.
 * @constants: Describes the constants.
 */
typedef struct {
  guint16 blob_type;
  guint16 deprecated   : 1;
  guint16 reserved     :15;
  guint32 name;

  guint32 gtype_name;
  guint32 gtype_init;
  guint16 gtype_struct;

  guint16 n_prerequisites;
  guint16 n_properties;
  guint16 n_methods;
  guint16 n_signals;
  guint16 n_vfuncs;
  guint16 n_constants;

  guint32 reserved2;
  guint32 reserved3;

  guint16 prerequisites[];

#if 0
  /* variable-length parts of the blob */
  PropertyBlob        properties[];
  FunctionBlob        methods[];
  SignalBlob          signals[];
  VFuncBlob           vfuncs[];
  ConstantBlob        constants[];
#endif
} InterfaceBlob;

/**
 * ConstantBlob:
 * @type: The type of the value. In most cases this should be a numeric
 * type or string.
 * @size: The size of the value in bytes.
 * @offset: The offset of the value in the typelib.
 */
typedef struct {
  guint16        blob_type;
  guint16        deprecated   : 1;
  guint16        reserved     :15;
  guint32        name;

  SimpleTypeBlob type;

  guint32        size;
  guint32        offset;

  guint32        reserved2;
} ConstantBlob;

/**
 * AttributeBlob:
 * @offset: The offset of the typelib entry to which this attribute refers.
 * Attributes are kept sorted by offset, so that the attributes
 * of an entry can be found by a binary search.
 * @name: The name of the attribute, a string.
 * @value: The value of the attribute (also a string)
 */
typedef struct {
  guint32 offset;
  guint32 name;
  guint32 value;
} AttributeBlob;

/**
 * GTypelib:
 */
struct _GTypelib {
  /* <private> */
  guchar *data;
  gsize len;
  gboolean owns_memory;
  GMappedFile *mfile;
  GList *modules;
  gboolean open_attempted;
};

DirEntry *g_typelib_get_dir_entry (GTypelib *typelib,
				   guint16   index);

void      g_typelib_check_sanity (void);

#define   g_typelib_get_string(typelib,offset) ((const gchar*)&(typelib->data)[(offset)])


/**
 * GTypelibError:
 * @G_TYPELIB_ERROR_INVALID: the typelib is invalid
 * @G_TYPELIB_ERROR_INVALID_HEADER: the typelib header is invalid
 * @G_TYPELIB_ERROR_INVALID_DIRECTORY: the typelib directory is invalid
 * @G_TYPELIB_ERROR_INVALID_ENTRY: a typelib entry is invalid
 * @G_TYPELIB_ERROR_INVALID_BLOB: a typelib blob is invalid
 *
 * A error set while validating the #GTypelib
 */
typedef enum
{
  G_TYPELIB_ERROR_INVALID,
  G_TYPELIB_ERROR_INVALID_HEADER,
  G_TYPELIB_ERROR_INVALID_DIRECTORY,
  G_TYPELIB_ERROR_INVALID_ENTRY,
  G_TYPELIB_ERROR_INVALID_BLOB
} GTypelibError;

#define G_TYPELIB_ERROR (g_typelib_error_quark ())

GQuark g_typelib_error_quark (void);

gboolean g_typelib_validate (GTypelib  *typelib,
			     GError    **error);


G_END_DECLS

#endif  /* __G_TYPELIB_H__ */