Docs: document enumeration mapping iterator API

[babeltrace.git] / include / babeltrace / ctf-ir / field-types.h

#ifndef BABELTRACE_CTF_IR_FIELD_TYPES_H
#define BABELTRACE_CTF_IR_FIELD_TYPES_H

/*
 * BabelTrace - CTF IR: Event field types
 *
 * Copyright 2013, 2014 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * The Common Trace Format (CTF) Specification is available at
 * http://www.efficios.com/ctf
 */

#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
@defgroup ctfirfieldtypes CTF IR field types
@ingroup ctfir
@brief CTF IR field types.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>field type</em></strong> is a field type that you
can use to create concrete @fields.

You can create a @field object from a CTF IR field type object
with bt_ctf_field_create().

In the CTF IR hierarchy, you can set the root field types of three
objects:

- \ref ctfirtraceclass
  - Trace packet header field type: bt_ctf_trace_set_packet_header_type().
- \ref ctfirstreamclass
  - Stream packet context field type:
    bt_ctf_stream_class_set_packet_context_type().
  - Stream event header field type:
    bt_ctf_stream_class_set_event_header_type().
  - Stream event context field type:
    bt_ctf_stream_class_set_event_context_type().
- \ref ctfireventclass
  - Event context field type: bt_ctf_event_class_set_context_type().
  - Event payload field type: bt_ctf_event_class_set_payload_type().

As of Babeltrace \btversion, those six previous "root" field types
\em must be @structft objects.

If, at any level within a given root field type, you add a @seqft or a
@varft, you do not need to specify its associated length
or tag field type: the length or tag string is enough for the Babeltrace
system to resolve the needed field type depending on where this
dynamic field type is located within the whole hierarchy. It is
guaranteed that this automatic resolving is performed for all the field
types contained in a given
\link ctfirstreamclass CTF IR stream class\endlink (and in its
children \link ctfireventclass CTF IR event classes\endlink) once you
add it to a \link ctfirtraceclass CTF IR trace class\endlink with
bt_ctf_trace_add_stream_class(). Once a stream class is the child of
a trace class, this automatic resolving is performed for the field
types of an event class when you add it with
bt_ctf_stream_class_add_event_class(). If the system cannot find a path
to a field in the hierarchy for a dynamic field type, the adding
function fails.

The standard CTF field types are:

<table>
  <tr>
    <th>Type ID
    <th>CTF IR field type
    <th>CTF IR field which you can create from this field type
  </tr>
  <tr>
    <td>#BT_CTF_TYPE_ID_INTEGER
    <td>\ref ctfirintfieldtype
    <td>\ref ctfirintfield
  </tr>
  <tr>
    <td>#BT_CTF_TYPE_ID_FLOAT
    <td>\ref ctfirfloatfieldtype
    <td>\ref ctfirfloatfield
  </tr>
  <tr>
    <td>#BT_CTF_TYPE_ID_ENUM
    <td>\ref ctfirenumfieldtype
    <td>\ref ctfirenumfield
  </tr>
  <tr>
    <td>#BT_CTF_TYPE_ID_STRING
    <td>\ref ctfirstringfieldtype
    <td>\ref ctfirstringfield
  </tr>
  <tr>
    <td>#BT_CTF_TYPE_ID_STRUCT
    <td>\ref ctfirstructfieldtype
    <td>\ref ctfirstructfield
  </tr>
  <tr>
    <td>#BT_CTF_TYPE_ID_ARRAY
    <td>\ref ctfirarrayfieldtype
    <td>\ref ctfirarrayfield
  </tr>
  <tr>
    <td>#BT_CTF_TYPE_ID_SEQUENCE
    <td>\ref ctfirseqfieldtype
    <td>\ref ctfirseqfield
  </tr>
  <tr>
    <td>#BT_CTF_TYPE_ID_VARIANT
    <td>\ref ctfirvarfieldtype
    <td>\ref ctfirvarfield
  </tr>
</table>

Each field type has its own <strong>type ID</strong> (see
#bt_ctf_type_id). You get the type ID of a field type object
with bt_ctf_field_type_get_type_id().

You can get a deep copy of a field type with bt_ctf_field_type_copy().
This function resets, in the field type copy, the resolved field type
of the dynamic field types. The automatic resolving can be done again
when you eventually call bt_ctf_event_create(),
bt_ctf_stream_class_add_event_class(), or
bt_ctf_trace_add_stream_class().

You \em must always use bt_ctf_field_type_compare() to compare two
field types. Since some parts of the Babeltrace system can copy field
types behind the scenes, you \em cannot rely on a simple field type
pointer comparison.

As with any Babeltrace object, CTF IR field type objects have
<a href="https://en.wikipedia.org/wiki/Reference_counting">reference
counts</a>. See \ref refs to learn more about the reference counting
management of Babeltrace objects.

The following functions can \em freeze field type objects:

- bt_ctf_field_create() freezes its field type parameter.
- bt_ctf_stream_class_add_event_class(), if its
  \link ctfirstreamclass CTF IR stream class\endlink parameter has a
  \link ctfirtraceclass CTF IR trace class\endlink parent, freezes
  the root field types of its
  \link ctfireventclass CTF IR event class\endlink parameter.
- bt_ctf_trace_add_stream_class() freezes the root field types of the
  whole trace class hierarchy (trace class, children stream classes,
  and their children event classes).
- bt_ctf_writer_create_stream() freezes the root field types of the
  whole CTF writer's trace class hierarchy.
- bt_ctf_event_create() freezes the root field types of its event class
  parameter and of ther parent stream class of this event class.

You cannot modify a frozen field type object: it is considered
immutable, except for \link refs reference counting\endlink.

@sa ctfirfields
@sa \ref ctfirfieldtypesexamples "Examples"

@file
@brief CTF IR field types type and functions.
@sa ctfirfieldtypes

@addtogroup ctfirfieldtypes
@{
*/

/**
@struct bt_ctf_field_type
@brief A CTF IR field type.
@sa ctfirfieldtypes
*/
struct bt_ctf_field_type;
struct bt_ctf_event_class;
struct bt_ctf_event;
struct bt_ctf_field;
struct bt_ctf_field_path;
struct bt_ctf_field_type_enumeration_mapping_iterator;

/** @cond DOCUMENT */

/*
 * Babeltrace 1.x enumerations that were also used in CTF writer's API.
 * They are left here for backward compatibility reasons, but
 * enum bt_ctf_type_id and enum bt_ctf_string_encoding should be used
 * in new code. Both new enumerations are compatible with their legacy
 * counterpart.
 */
enum ctf_type_id {
        CTF_TYPE_UNKNOWN = 0,
        CTF_TYPE_INTEGER,
        CTF_TYPE_FLOAT,
        CTF_TYPE_ENUM,
        CTF_TYPE_STRING,
        CTF_TYPE_STRUCT,
        CTF_TYPE_UNTAGGED_VARIANT,
        CTF_TYPE_VARIANT,
        CTF_TYPE_ARRAY,
        CTF_TYPE_SEQUENCE,
        NR_CTF_TYPES,
};

/*
 * Old enum.
 */
enum ctf_string_encoding {
        CTF_STRING_NONE = 0,
        CTF_STRING_UTF8,
        CTF_STRING_ASCII,
        CTF_STRING_UNKNOWN,
};

/** @endcond */

/**
@brief  CTF scope.
*/
enum bt_ctf_scope {
        /// Unknown, used for errors.
        BT_CTF_SCOPE_UNKNOWN = -1,

        /// Trace packet header.
        BT_CTF_SCOPE_TRACE_PACKET_HEADER = 1,

        /// Stream packet context.
        BT_CTF_SCOPE_STREAM_PACKET_CONTEXT = 2,

        /// Stream event header.
        BT_CTF_SCOPE_STREAM_EVENT_HEADER = 3,

        /// Stream event context.
        BT_CTF_SCOPE_STREAM_EVENT_CONTEXT = 4,

        /// Event context.
        BT_CTF_SCOPE_EVENT_CONTEXT = 5,

        /// Event payload.
        BT_CTF_SCOPE_EVENT_PAYLOAD = 6,

        /// @cond DOCUMENT
        BT_CTF_SCOPE_ENV = 0,
        BT_CTF_SCOPE_EVENT_FIELDS = 6,
        /// @endcond
};

/**
@name Type information
@{
*/

/**
@brief  Type ID of a @ft.
*/
enum bt_ctf_type_id {
        /// Unknown, used for errors.
        BT_CTF_TYPE_ID_UNKNOWN = CTF_TYPE_UNKNOWN,

        /// \ref ctfirintfieldtype
        BT_CTF_TYPE_ID_INTEGER = CTF_TYPE_INTEGER,

        /// \ref ctfirfloatfieldtype
        BT_CTF_TYPE_ID_FLOAT = CTF_TYPE_FLOAT,

        /// \ref ctfirenumfieldtype
        BT_CTF_TYPE_ID_ENUM = CTF_TYPE_ENUM,

        /// \ref ctfirstringfieldtype
        BT_CTF_TYPE_ID_STRING = CTF_TYPE_STRING,

        /// \ref ctfirstructfieldtype
        BT_CTF_TYPE_ID_STRUCT = CTF_TYPE_STRUCT,

        /// @cond DOCUMENT
        BT_CTF_TYPE_ID_UNTAGGED_VARIANT = CTF_TYPE_UNTAGGED_VARIANT,
        /// @endcond

        /// \ref ctfirarrayfieldtype
        BT_CTF_TYPE_ID_ARRAY = CTF_TYPE_ARRAY,

        /// \ref ctfirseqfieldtype
        BT_CTF_TYPE_ID_SEQUENCE = CTF_TYPE_SEQUENCE,

        /// \ref ctfirvarfieldtype
        BT_CTF_TYPE_ID_VARIANT = CTF_TYPE_VARIANT,

        /// Number of enumeration entries.
        BT_CTF_NR_TYPE_IDS = NR_CTF_TYPES,
};

/**
@brief  Returns the type ID of the @ft \p field_type.

@param[in] field_type   Field type of which to get the type ID.
@returns                Type ID of \p field_type,
                        or #BT_CTF_TYPE_ID_UNKNOWN on error.

@prenotnull{field_type}
@postrefcountsame{field_type}

@sa #bt_ctf_type_id: CTF IR field type ID.
@sa bt_ctf_field_type_is_integer(): Returns whether or not a given
        field type is a @intft.
@sa bt_ctf_field_type_is_floating_point(): Returns whether or not a
        given field type is a @floatft.
@sa bt_ctf_field_type_is_enumeration(): Returns whether or not a given
        field type is a @enumft.
@sa bt_ctf_field_type_is_string(): Returns whether or not a given
        field type is a @stringft.
@sa bt_ctf_field_type_is_structure(): Returns whether or not a given
        field type is a @structft.
@sa bt_ctf_field_type_is_array(): Returns whether or not a given
        field type is a @arrayft.
@sa bt_ctf_field_type_is_sequence(): Returns whether or not a given
        field type is a @seqft.
@sa bt_ctf_field_type_is_variant(): Returns whether or not a given
        field type is a @varft.
*/
extern enum bt_ctf_type_id bt_ctf_field_type_get_type_id(
                struct bt_ctf_field_type *field_type);

/**
@brief  Returns whether or not the @ft \p field_type is a @intft.

@param[in] field_type   Field type to check (can be \c NULL).
@returns                1 if \p field_type is an integer field type,
                        or 0 otherwise (including if \p field_type is
                        \c NULL).

@prenotnull{field_type}
@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_type_id(): Returns the type ID of a given
        field type.
*/
extern int bt_ctf_field_type_is_integer(struct bt_ctf_field_type *field_type);

/**
@brief  Returns whether or not the @ft \p field_type is a @floatft.

@param[in] field_type   Field type to check (can be \c NULL).
@returns                1 if \p field_type is a floating point
                        number field type,
                        or 0 otherwise (including if \p field_type is
                        \c NULL).

@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_type_id(): Returns the type ID of a given
        field type.
*/
extern int bt_ctf_field_type_is_floating_point(struct bt_ctf_field_type *field_type);

/**
@brief  Returns whether or not the @ft \p field_type is a @enumft.

@param[in] field_type   Field type to check (can be \c NULL).
@returns                1 if \p field_type is an enumeration field type,
                        or 0 otherwise (including if \p field_type is
                        \c NULL).

@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_type_id(): Returns the type ID of a given
        field type.
*/
extern int bt_ctf_field_type_is_enumeration(struct bt_ctf_field_type *field_type);

/**
@brief  Returns whether or not the @ft \p field_type is a @stringft.

@param[in] field_type   Field type to check (can be \c NULL).
@returns                1 if \p field_type is a string field type,
                        or 0 otherwise (including if \p field_type is
                        \c NULL).

@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_type_id(): Returns the type ID of a given
        field type.
*/
extern int bt_ctf_field_type_is_string(struct bt_ctf_field_type *field_type);

/**
@brief  Returns whether or not the @ft \p field_type is a @structft.

@param[in] field_type   Field type to check (can be \c NULL).
@returns                1 if \p field_type is a structure field type,
                        or 0 otherwise (including if \p field_type is
                        \c NULL).

@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_type_id(): Returns the type ID of a given
        field type.
*/
extern int bt_ctf_field_type_is_structure(struct bt_ctf_field_type *field_type);

/**
@brief  Returns whether or not the @ft \p field_type is a @arrayft.

@param[in] field_type   Field type to check (can be \c NULL).
@returns                1 if \p field_type is an array field type,
                        or 0 otherwise (including if \p field_type is
                        \c NULL).

@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_type_id(): Returns the type ID of a given
        field type.
*/
extern int bt_ctf_field_type_is_array(struct bt_ctf_field_type *field_type);

/**
@brief  Returns whether or not the @ft \p field_type is a @seqft.

@param[in] field_type   Field type to check (can be \c NULL).
@returns                1 if \p field_type is a sequence field type,
                        or 0 otherwise (including if \p field_type is
                        \c NULL).

@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_type_id(): Returns the type ID of a given
        field type.
*/
extern int bt_ctf_field_type_is_sequence(struct bt_ctf_field_type *field_type);

/**
@brief  Returns whether or not the @ft \p field_type is a @varft.

@param[in] field_type   Field type to check (can be \c NULL).
@returns                1 if \p field_type is a variant field type,
                        or 0 otherwise (including if \p field_type is
                        \c NULL).

@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_type_id(): Returns the type ID of a given
        field type.
*/
extern int bt_ctf_field_type_is_variant(struct bt_ctf_field_type *field_type);

/** @} */

/**
@name Common properties types and functions
@{
*/

/**
@brief  <a href="https://en.wikipedia.org/wiki/Endianness">Byte order</a>
        of a @ft.
*/
enum bt_ctf_byte_order {
        /// Unknown, used for errors.
        BT_CTF_BYTE_ORDER_UNKNOWN = -1,

        /*
         * Note that native, in the context of the CTF specification, is defined
         * as "the byte order described in the trace" and does not mean that the
         * host's endianness will be used.
         */
        /// Native (default) byte order.
        BT_CTF_BYTE_ORDER_NATIVE = 0,

        /// Little-endian.
        BT_CTF_BYTE_ORDER_LITTLE_ENDIAN,

        /// Big-endian.
        BT_CTF_BYTE_ORDER_BIG_ENDIAN,

        /// Network byte order (big-endian).
        BT_CTF_BYTE_ORDER_NETWORK,
};

/**
@brief  String encoding of a @ft.
*/
enum bt_ctf_string_encoding {
        /// Unknown, used for errors.
        BT_CTF_STRING_ENCODING_UNKNOWN = CTF_STRING_UNKNOWN,

        /// No encoding.
        BT_CTF_STRING_ENCODING_NONE = CTF_STRING_NONE,

        /// <a href="https://en.wikipedia.org/wiki/UTF-8">UTF-8</a>.
        BT_CTF_STRING_ENCODING_UTF8 = CTF_STRING_UTF8,

        /// <a href="https://en.wikipedia.org/wiki/ASCII">ASCII</a>.
        BT_CTF_STRING_ENCODING_ASCII = CTF_STRING_ASCII,
};

/**
@brief  Returns the alignment of the @fields described by
        the @ft \p field_type.

@param[in] field_type   Field type which describes the
                        fields of which to get the alignment.
@returns                Alignment of the fields described by
                        \p field_type, or a negative value on error.

@prenotnull{field_type}
@postrefcountsame{field_type}

@sa bt_ctf_field_type_set_alignment(): Sets the alignment
        of the fields described by a given field type.
*/
extern int bt_ctf_field_type_get_alignment(
                struct bt_ctf_field_type *field_type);

/**
@brief  Sets the alignment of the @fields described by the
        @ft \p field_type to \p alignment.

\p alignment \em must be greater than 0 and a power of two.

@param[in] field_type   Field type which describes the fields of
                        which to set the alignment.
@param[in] alignment    Alignment of the fields described by
                        \p field_type.
@returns                0 on success, or a negative value on error.

@prenotnull{field_type}
@prehot{field_type}
@pre \p alignment is greater than 0 and a power of two.
@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_alignment(): Returns the alignment of the
        fields described by a given field type.
*/
extern int bt_ctf_field_type_set_alignment(struct bt_ctf_field_type *field_type,
                unsigned int alignment);

/**
@brief  Returns the byte order of the @fields described by
        the @ft \p field_type.

You can only call this function if \p field_type is a @intft, a
@floatft, or a @enumft.

@param[in] field_type   Field type which describes the
                        fields of which to get the byte order.
@returns                Byte order of the fields described by
                        \p field_type, or #BT_CTF_BYTE_ORDER_UNKNOWN on
                        error.

@prenotnull{field_type}
@pre \p field_type is a @intft, a @floatft, or a @enumft.
@postrefcountsame{field_type}

@sa bt_ctf_field_type_set_byte_order(): Sets the byte order
        of the fields described by a given field type.
*/
extern enum bt_ctf_byte_order bt_ctf_field_type_get_byte_order(
                struct bt_ctf_field_type *field_type);

/**
@brief  Sets the byte order of the @fields described by the
        @ft \p field_type to \p byte_order.

If \p field_type is a compound field type, this function also
recursively sets the byte order of its children to \p byte_order.

@param[in] field_type   Field type which describes the fields of
                        which to set the byte order.
@param[in] byte_order   Alignment of the fields described by
                        \p field_type.
@returns                0 on success, or a negative value on error.

@prenotnull{field_type}
@prehot{field_type}
@pre \p byte_order is #BT_CTF_BYTE_ORDER_NATIVE,
        #BT_CTF_BYTE_ORDER_LITTLE_ENDIAN, #BT_CTF_BYTE_ORDER_BIG_ENDIAN,
        or #BT_CTF_BYTE_ORDER_NETWORK.
@postrefcountsame{field_type}

@sa bt_ctf_field_type_get_byte_order(): Returns the byte order of the
        fields described by a given field type.
*/
extern int bt_ctf_field_type_set_byte_order(
                struct bt_ctf_field_type *field_type,
                enum bt_ctf_byte_order byte_order);

/** @} */

/**
@name Utility functions
@{
*/

/**
@brief  Returns whether or not the @ft \p field_type_a
        is equivalent to the field type \p field_type_b.

You \em must use this function to compare two field types: it is not
safe to compare two pointer values directly, because, for internal
reasons, some parts of the Babeltrace system can copy user field types
and discard the original ones.

@param[in] field_type_a Field type to compare to \p field_type_b.
@param[in] field_type_b Field type to compare to \p field_type_a.
@returns                0 if \p field_type_a is equivalent to
                        \p field_type_b, 1 if they are not equivalent,
                        or a negative value on error.

@prenotnull{field_type_a}
@prenotnull{field_type_b}
@postrefcountsame{field_type_a}
@postrefcountsame{field_type_b}
*/
extern int bt_ctf_field_type_compare(struct bt_ctf_field_type *field_type_a,
                struct bt_ctf_field_type *field_type_b);

/**
@brief  Creates a \em deep copy of the @ft \p field_type.

You can copy a frozen field type: the resulting copy is
<em>not frozen</em>.

This function resets the tag field type of a copied @varft. The
automatic field resolving which some functions of the API perform
can set it again when the returned field type is used (learn more
in the detailed description of this module).

@param[in] field_type   Field type to copy.
@returns                Deep copy of \p field_type on success,
                        or \c NULL on error.

@prenotnull{field_type}
@postrefcountsame{field_type}
@postsuccessrefcountret1
@post <strong>On success</strong>, the returned field type is not frozen.
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_copy(
                struct bt_ctf_field_type *field_type);

/** @} */

/** @} */

/**
@defgroup ctfirintfieldtype CTF IR integer field type
@ingroup ctfirfieldtypes
@brief CTF IR integer field type.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>integer field type</em></strong> is a field type that
you can use to create concrete @intfield objects.

You can create an integer field type
with bt_ctf_field_type_integer_create().

An integer field type has the following properties:

<table>
  <tr>
    <th>Property
    <th>Value at creation
    <th>Getter
    <th>Setter
  </tr>
  <tr>
    <td>\b Alignment (bits) of the described integer fields
    <td>1
    <td>bt_ctf_field_type_get_alignment()
    <td>bt_ctf_field_type_set_alignment()
  </tr>
  <tr>
    <td><strong>Byte order</strong> of the described integer fields
    <td>#BT_CTF_BYTE_ORDER_NATIVE
    <td>bt_ctf_field_type_get_byte_order()
    <td>bt_ctf_field_type_set_byte_order()
  </tr>
  <tr>
    <td><strong>Storage size</strong> (bits) of the described
        integer fields
    <td>Specified at creation
    <td>bt_ctf_field_type_integer_get_size()
    <td>None: specified at creation (bt_ctf_field_type_integer_create())
  </tr>
  <tr>
    <td><strong>Signedness</strong> of the described integer fields
    <td>Unsigned
    <td>bt_ctf_field_type_integer_get_signed()
    <td>bt_ctf_field_type_integer_set_signed()
  </tr>
  <tr>
    <td><strong>Preferred display base</strong> of the described
        integer fields
    <td>#BT_CTF_INTEGER_BASE_DECIMAL
    <td>bt_ctf_field_type_integer_get_base()
    <td>bt_ctf_field_type_integer_set_base()
  </tr>
  <tr>
    <td>\b Encoding of the described integer fields
    <td>#BT_CTF_STRING_ENCODING_NONE
    <td>bt_ctf_field_type_integer_get_encoding()
    <td>bt_ctf_field_type_integer_set_encoding()
  </tr>
  <tr>
    <td><strong>Mapped
        \link ctfirclockclass CTF IR clock class\endlink</strong>
    <td>None
    <td>bt_ctf_field_type_integer_get_mapped_clock_class()
    <td>bt_ctf_field_type_integer_set_mapped_clock_class()
  </tr>
</table>

@sa ctfirintfield
@sa ctfirfieldtypes
@sa \ref ctfirfieldtypesexamples_intfieldtype "Examples"

@addtogroup ctfirintfieldtype
@{
*/

/**
@brief  Preferred display base (radix) of a @intft.
*/
enum bt_ctf_integer_base {
        /// Unknown, used for errors.
        BT_CTF_INTEGER_BASE_UNKNOWN = -1,

        /// Binary.
        BT_CTF_INTEGER_BASE_BINARY = 2,

        /// Octal.
        BT_CTF_INTEGER_BASE_OCTAL = 8,

        /// Decimal.
        BT_CTF_INTEGER_BASE_DECIMAL = 10,

        /// Hexadecimal.
        BT_CTF_INTEGER_BASE_HEXADECIMAL = 16,
};

/**
@brief  Creates a default @intft with \p size bits as the storage size
        of the @intfields it describes.

@param[in] size Storage size (bits) of the described integer fields.
@returns        Created integer field type, or \c NULL on error.

@pre \p size is greater than 0 and lesser than or equal to 64.
@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_integer_create(
                unsigned int size);

/**
@brief  Returns the storage size, in bits, of the @intfields
        described by the @intft \p int_field_type.

@param[in] int_field_type       Integer field type which describes the
                                integer fields of which to get the
                                storage size.
@returns                        Storage size (bits) of the integer
                                fields described by \p int_field_type,
                                or a negative value on error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@postrefcountsame{int_field_type}
*/
extern int bt_ctf_field_type_integer_get_size(
                struct bt_ctf_field_type *int_field_type);

/**
@brief  Returns whether or not the @intfields described by the @intft
        \p int_field_type are signed.

@param[in] int_field_type       Integer field type which describes the
                                integer fields of which to get the
                                signedness.
@returns                        1 if the integer fields described by
                                \p int_field_type are signed, 0 if they
                                are unsigned, or a negative value on
                                error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@postrefcountsame{int_field_type}

@sa bt_ctf_field_type_integer_set_signed(): Sets the signedness of the
        integer fields described by a given integer field type.
*/
extern int bt_ctf_field_type_integer_get_signed(
                struct bt_ctf_field_type *int_field_type);

/**
@brief  Sets whether or not the @intfields described by
        the @intft \p int_field_type are signed.

@param[in] int_field_type       Integer field type which describes the
                                integer fields of which to set the
                                signedness.
@param[in] is_signed            Signedness of the integer fields
                                described by \p int_field_type; 0 means
                                \em unsigned, 1 means \em signed.
@returns                        0 on success, or a negative value on error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@prehot{int_field_type}
@pre \p is_signed is 0 or 1.
@postrefcountsame{event_class}

@sa bt_ctf_field_type_integer_get_signed(): Returns the signedness of
        the integer fields described by a given integer field type.
*/
extern int bt_ctf_field_type_integer_set_signed(
                struct bt_ctf_field_type *int_field_type, int is_signed);

/**
@brief  Returns the preferred display base (radix) of the @intfields
        described by the @intft \p int_field_type.

@param[in] int_field_type       Integer field type which describes the
                                integer fields of which to get the
                                preferred display base.
@returns                        Preferred display base of the integer
                                fields described by \p int_field_type,
                                or #BT_CTF_INTEGER_BASE_UNKNOWN on
                                error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@postrefcountsame{int_field_type}

@sa bt_ctf_field_type_integer_set_base(): Sets the preferred display
        base of the integer fields described by a given integer field
        type.
*/
extern enum bt_ctf_integer_base bt_ctf_field_type_integer_get_base(
                struct bt_ctf_field_type *int_field_type);

/**
@brief  Sets the preferred display base (radix) of the @intfields
        described by the @intft \p int_field_type to \p base.

@param[in] int_field_type       Integer field type which describes the
                                integer fields of which to set the
                                preferred display base.
@param[in] base                 Preferred display base of the integer
                                fields described by \p int_field_type.
@returns                        0 on success, or a negative value on error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@prehot{int_field_type}
@pre \p base is #BT_CTF_INTEGER_BASE_BINARY, #BT_CTF_INTEGER_BASE_OCTAL,
        #BT_CTF_INTEGER_BASE_DECIMAL, or
        #BT_CTF_INTEGER_BASE_HEXADECIMAL.
@postrefcountsame{int_field_type}

@sa bt_ctf_field_type_integer_get_base(): Returns the preferred display
        base of the integer fields described by a given
        integer field type.
*/
extern int bt_ctf_field_type_integer_set_base(
                struct bt_ctf_field_type *int_field_type,
                enum bt_ctf_integer_base base);

/**
@brief  Returns the encoding of the @intfields described by
        the @intft \p int_field_type.

@param[in] int_field_type       Integer field type which describes the
                                integer fields of which to get the
                                encoding.
@returns                        Encoding of the integer
                                fields described by \p int_field_type,
                                or #BT_CTF_STRING_ENCODING_UNKNOWN on
                                error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@postrefcountsame{int_field_type}

@sa bt_ctf_field_type_integer_set_encoding(): Sets the encoding
        of the integer fields described by a given integer field type.
*/
extern enum bt_ctf_string_encoding bt_ctf_field_type_integer_get_encoding(
                struct bt_ctf_field_type *int_field_type);

/**
@brief  Sets the encoding of the @intfields described by the @intft
        \p int_field_type to \p encoding.

You can use this property, in CTF IR, to create "text" @arrayfts or
@seqfts. A text array field type is array field type with an unsigned,
8-bit integer field type having an encoding as its element field type.

@param[in] int_field_type       Integer field type which describes the
                                integer fields of which to set the
                                encoding.
@param[in] encoding             Encoding of the integer
                                fields described by \p int_field_type.
@returns                        0 on success, or a negative value on error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@prehot{int_field_type}
@pre \p encoding is #BT_CTF_STRING_ENCODING_NONE,
        #BT_CTF_STRING_ENCODING_ASCII, or
        #BT_CTF_STRING_ENCODING_UTF8.
@postrefcountsame{int_field_type}

@sa bt_ctf_field_type_integer_get_encoding(): Returns the encoding of
        the integer fields described by a given integer field type.
*/
extern int bt_ctf_field_type_integer_set_encoding(
                struct bt_ctf_field_type *int_field_type,
                enum bt_ctf_string_encoding encoding);

/**
@brief  Returns the \link ctfirclockclass CTF IR clock class\endlink
        mapped to the @intft \p int_field_type.

The mapped clock class, if any, indicates the class of the clock which
an @intfield described by \p int_field_type should sample or update.
This mapped clock class is only indicative.

@param[in] int_field_type       Integer field type of which to get the
                                mapped clock class.
@returns                        Mapped clock class of \p int_field_type,
                                or \c NULL if there's no mapped clock
                                class or on error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@postrefcountsame{int_field_type}
@postsuccessrefcountretinc

@sa bt_ctf_field_type_integer_set_mapped_clock_class(): Sets the mapped
        clock class of a given integer field type.
*/
extern struct bt_ctf_clock_class *bt_ctf_field_type_integer_get_mapped_clock_class(
                struct bt_ctf_field_type *int_field_type);

/**
@brief  Sets the \link ctfirclockclass CTF IR clock class\endlink mapped
        to the @intft \p int_field_type to \p clock_class.

The mapped clock class, if any, indicates the class of the clock which
an integer field described by \p int_field_type should sample or update.
This mapped clock class is only indicative.

@param[in] int_field_type       Integer field type of which to set the
                                mapped clock class.
@param[in] clock_class          Mapped clock class of \p int_field_type.
@returns                        0 on success, or a negative value on error.

@prenotnull{int_field_type}
@prenotnull{clock_class}
@preisintft{int_field_type}
@prehot{int_field_type}
@postrefcountsame{int_field_type}
@postsuccessrefcountinc{clock_class}

@sa bt_ctf_field_type_integer_get_mapped_clock_class(): Returns the mapped
        clock class of a given integer field type.
*/
extern int bt_ctf_field_type_integer_set_mapped_clock_class(
                struct bt_ctf_field_type *int_field_type,
                struct bt_ctf_clock_class *clock_class);

/** @} */

/**
@defgroup ctfirfloatfieldtype CTF IR floating point number field type
@ingroup ctfirfieldtypes
@brief CTF IR floating point number field type.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>floating point number field type</em></strong> is
a field type that you can use to create concrete @floatfields.

You can create a floating point number field type
with bt_ctf_field_type_floating_point_create().

A floating point number field type has the following properties:

<table>
  <tr>
    <th>Property
    <th>Value at creation
    <th>Getter
    <th>Setter
  </tr>
  <tr>
    <td>\b Alignment (bits) of the described floating point
        number fields
    <td>1
    <td>bt_ctf_field_type_get_alignment()
    <td>bt_ctf_field_type_set_alignment()
  </tr>
  <tr>
    <td><strong>Byte order</strong> of the described floating point
        number fields
    <td>#BT_CTF_BYTE_ORDER_NATIVE
    <td>bt_ctf_field_type_get_byte_order()
    <td>bt_ctf_field_type_set_byte_order()
  </tr>
  <tr>
    <td><strong>Exponent storage size</strong> (bits) of the described
        floating point number fields
    <td>8
    <td>bt_ctf_field_type_floating_point_get_exponent_digits()
    <td>bt_ctf_field_type_floating_point_set_exponent_digits()
  </tr>
  <tr>
    <td><strong>Mantissa and sign storage size</strong> (bits) of the
        described floating point number fields
    <td>24 (23-bit mantissa, 1-bit sign)
    <td>bt_ctf_field_type_floating_point_get_mantissa_digits()
    <td>bt_ctf_field_type_floating_point_set_mantissa_digits()
  </tr>
</table>

@sa ctfirfloatfield
@sa ctfirfieldtypes
@sa \ref ctfirfieldtypesexamples_floatfieldtype "Examples"

@addtogroup ctfirfloatfieldtype
@{
*/

/**
@brief  Creates a default @floatft.

@returns        Created floating point number field type,
                or \c NULL on error.

@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_floating_point_create(void);

/**
@brief  Returns the exponent storage size of the @floatfields
        described by the @floatft \p float_field_type.

@param[in] float_field_type     Floating point number field type which
                                describes the floating point number
                                fields of which to get the exponent
                                storage size.
@returns                        Exponent storage size of the
                                floating point number fields
                                described by \p float_field_type,
                                or a negative value on error.

@prenotnull{float_field_type}
@preisfloatft{float_field_type}
@postrefcountsame{float_field_type}

@sa bt_ctf_field_type_floating_point_set_exponent_digits(): Sets the
        exponent storage size of the floating point number fields
        described by a given floating point number field type.
*/
extern int bt_ctf_field_type_floating_point_get_exponent_digits(
                struct bt_ctf_field_type *float_field_type);

/**
@brief  Sets the exponent storage size of the @floatfields described by
        the @floatft \p float_field_type to \p exponent_size.

As of Babeltrace \btversion, \p exponent_size can only be 8 or 11.

@param[in] float_field_type     Floating point number field type which
                                describes the floating point number
                                fields of which to set the exponent
                                storage size.
@param[in] exponent_size        Exponent storage size of the floating
                                point number fields described by \p
                                float_field_type.
@returns                        0 on success, or a negative value on error.

@prenotnull{float_field_type}
@preisfloatft{float_field_type}
@prehot{float_field_type}
@pre \p exponent_size is 8 or 11.
@postrefcountsame{float_field_type}

@sa bt_ctf_field_type_floating_point_get_exponent_digits(): Returns the
        exponent storage size of the floating point number fields
        described by a given floating point number field type.
*/
extern int bt_ctf_field_type_floating_point_set_exponent_digits(
                struct bt_ctf_field_type *float_field_type,
                unsigned int exponent_size);

/**
@brief  Returns the mantissa and sign storage size of the @floatfields
        described by the @floatft \p float_field_type.

On success, the returned value is the sum of the mantissa \em and
sign storage sizes.

@param[in] float_field_type     Floating point number field type which
                                describes the floating point number
                                fields of which to get the mantissa and
                                sign storage size.
@returns                        Mantissa and sign storage size of the
                                floating point number fields
                                described by \p float_field_type,
                                or a negative value on error.

@prenotnull{float_field_type}
@preisfloatft{float_field_type}
@postrefcountsame{float_field_type}

@sa bt_ctf_field_type_floating_point_set_mantissa_digits(): Sets the
        mantissa and size storage size of the floating point number
        fields described by a given floating point number field type.
*/
extern int bt_ctf_field_type_floating_point_get_mantissa_digits(
                struct bt_ctf_field_type *float_field_type);

/**
@brief  Sets the mantissa and sign storage size of the @floatfields
        described by the @floatft \p float_field_type to \p
        mantissa_sign_size.

As of Babeltrace \btversion, \p mantissa_sign_size can only be 24 or 53.

@param[in] float_field_type     Floating point number field type which
                                describes the floating point number
                                fields of which to set the mantissa and
                                sign storage size.
@param[in] mantissa_sign_size   Mantissa and sign storage size of the
                                floating point number fields described
                                by \p float_field_type.
@returns                        0 on success, or a negative value on error.

@prenotnull{float_field_type}
@preisfloatft{float_field_type}
@prehot{float_field_type}
@pre \p mantissa_sign_size is 24 or 53.
@postrefcountsame{float_field_type}

@sa bt_ctf_field_type_floating_point_get_mantissa_digits(): Returns the
        mantissa and sign storage size of the floating point number
        fields described by a given floating point number field type.
*/
extern int bt_ctf_field_type_floating_point_set_mantissa_digits(
                struct bt_ctf_field_type *float_field_type,
                unsigned int mantissa_sign_size);

/** @} */

/**
@defgroup ctfirenumfieldtype CTF IR enumeration field type
@ingroup ctfirfieldtypes
@brief CTF IR enumeration field type.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>enumeration field type</em></strong> is
a field type that you can use to create concrete @enumfields.

You can create an enumeration field type with
bt_ctf_field_type_enumeration_create(). This function needs a @intft
which represents the storage field type of the created enumeration field
type. In other words, an enumeration field type wraps an integer field
type and adds label-value mappings to it.

An enumeration mapping has:

- A <strong>name</strong>.
- A <strong>range of values</strong> given by a beginning and an ending
  value, both included in the range.

You can add a mapping to an enumeration field type with
bt_ctf_field_type_enumeration_add_mapping() or
bt_ctf_field_type_enumeration_add_mapping_unsigned(), depending on the
signedness of the wrapped @intft.

Many mappings can share the same name, and the ranges of a given
enumeration field type are allowed to overlap. For example,
this is a valid set of mappings:

@verbatim
APPLE  -> [  3, 19]
BANANA -> [-15,  1]
CHERRY -> [ 25, 34]
APPLE  -> [ 55, 55]
@endverbatim

The following set of mappings is also valid:

@verbatim
APPLE  -> [  3, 19]
BANANA -> [-15,  1]
CHERRY -> [ 25, 34]
APPLE  -> [ 30, 55]
@endverbatim

Here, the range of the second \c APPLE mapping overlaps the range of
the \c CHERRY mapping.

@sa ctfirenumfield
@sa ctfirfieldtypes
@sa ctfirenummappingiter

@addtogroup ctfirenumfieldtype
@{
*/

/**
@brief  Creates a default @enumft wrapping the @intft \p int_field_type.

@param[in] int_field_type       Integer field type wrapped by the
                                created enumeration field type.
@returns                        Created enumeration field type,
                                or \c NULL on error.

@prenotnull{int_field_type}
@preisintft{int_field_type}
@postsuccessrefcountinc{int_field_type}
@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_enumeration_create(
                struct bt_ctf_field_type *int_field_type);

/**
@brief  Returns the @intft wrapped by the @enumft \p enum_field_type.

@param[in] enum_field_type      Enumeration field type of which to get
                                the wrapped integer field type.
@returns                        Integer field type wrapped by
                                \p enum_field_type, or \c NULL on
                                error.

@prenotnull{enum_field_type}
@preisenumft{enum_field_type}
@postrefcountsame{enum_field_type}
@postsuccessrefcountretinc
*/
extern
struct bt_ctf_field_type *bt_ctf_field_type_enumeration_get_container_type(
                struct bt_ctf_field_type *enum_field_type);

/**
@brief  Returns the number of mappings contained in the
        @enumft \p enum_field_type.

@param[in] enum_field_type      Enumeration field type of which to get
                                the number of contained mappings.
@returns                        Number of mappings contained in
                                \p enum_field_type, or a negative
                                value on error.

@prenotnull{enum_field_type}
@preisenumft{enum_field_type}
@postrefcountsame{enum_field_type}
*/
extern int bt_ctf_field_type_enumeration_get_mapping_count(
                struct bt_ctf_field_type *enum_field_type);

/**
@brief  Returns the signed mapping of the @enumft
        \p enum_field_type at index \p index.

The @intft wrapped by \p enum_field_type, as returned by
bt_ctf_field_type_enumeration_get_container_type(), must be \b signed
to use this function.

On success, \p enum_field_type remains the sole owner of \p *name.

@param[in] enum_field_type      Enumeration field type of which to get
                                the mapping at index \p index.
@param[in] index                Index of the mapping to get from
                                \p enum_field_type.
@param[out] name                Returned name of the mapping at index
                                \p index.
@param[out] range_begin         Returned beginning of the range
                                (included) of the mapping at index \p
                                index.
@param[out] range_end           Returned end of the range (included) of
                                the mapping at index \p index.
@returns                        0 on success, or a negative value on error.

@prenotnull{enum_field_type}
@prenotnull{name}
@prenotnull{range_begin}
@prenotnull{range_end}
@preisenumft{enum_field_type}
@pre The wrapped @intft of \p enum_field_type is signed.
@pre \p index is lesser than the number of mappings contained in the
        enumeration field type \p enum_field_type (see
        bt_ctf_field_type_enumeration_get_mapping_count()).
@postrefcountsame{enum_field_type}

@sa bt_ctf_field_type_enumeration_get_mapping_unsigned(): Returns the
        unsigned mapping contained by a given enumeration field type
        at a given index.
*/
extern int bt_ctf_field_type_enumeration_get_mapping_signed(
                struct bt_ctf_field_type *enum_field_type, int index,
                const char **name, int64_t *range_begin, int64_t *range_end);

/**
@brief  Returns the unsigned mapping of the @enumft
        \p enum_field_type at index \p index.

The @intft wrapped by \p enum_field_type, as returned by
bt_ctf_field_type_enumeration_get_container_type(), must be
\b unsigned to use this function.

On success, \p enum_field_type remains the sole owner of \p *name.

@param[in] enum_field_type      Enumeration field type of which to get
                                the mapping at index \p index.
@param[in] index                Index of the mapping to get from
                                \p enum_field_type.
@param[out] name                Returned name of the mapping at index
                                \p index.
@param[out] range_begin         Returned beginning of the range
                                (included) of the mapping at index \p
                                index.
@param[out] range_end           Returned end of the range (included) of
                                the mapping at index \p index.
@returns                        0 on success, or a negative value on error.

@prenotnull{enum_field_type}
@prenotnull{name}
@prenotnull{range_begin}
@prenotnull{range_end}
@preisenumft{enum_field_type}
@pre The wrapped @intft of \p enum_field_type is unsigned.
@pre \p index is lesser than the number of mappings contained in the
        enumeration field type \p enum_field_type (see
        bt_ctf_field_type_enumeration_get_mapping_count()).
@postrefcountsame{enum_field_type}

@sa bt_ctf_field_type_enumeration_get_mapping_signed(): Returns the
        signed mapping contained by a given enumeration field type
        at a given index.
*/
extern int bt_ctf_field_type_enumeration_get_mapping_unsigned(
                struct bt_ctf_field_type *enum_field_type, int index,
                const char **name, uint64_t *range_begin,
                uint64_t *range_end);

/**
@brief  Returns a @enumiter on the mappings of the @enumft
        \p enum_field_type that match \p name.

@param[in] enum_field_type      Enumeration field type of which to get
                                the mapping at index \p index.
@param[in] name                 Name of the mappings to find.
@returns                        @enumiter that
                                match \p name, or \c NULL on error.

@prenotnull{enum_field_type}
@prenotnull{name}
@preisenumft{enum_field_type}
@postrefcountsame{enum_field_type}
@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type_enumeration_mapping_iterator *
bt_ctf_field_type_enumeration_find_mappings_by_name(
                struct bt_ctf_field_type *enum_field_type,
                const char *name);

/**
@brief  Returns the mappings of the @enumft
        \p enum_field_type that match \p value.

@param[in] enum_field_type      Enumeration field type of which to get
                                the mapping at index \p index.
@param[in] value                Signed value of the mappings to find.
@returns                        Iterator on enumeration mappings that
                                match \p value, or \c NULL on error.

@prenotnull{enum_field_type}
@prenotnull{name}
@preisenumft{enum_field_type}
@postrefcountsame{enum_field_type}
@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type_enumeration_mapping_iterator *
bt_ctf_field_type_enumeration_find_mappings_by_signed_value(
                struct bt_ctf_field_type *enum_field_type,
                int64_t value);

/**
@brief  Returns the mappings of the @enumft
        \p enum_field_type that match \p value.

@param[in] enum_field_type      Enumeration field type of which to get
                                the mapping at index \p index.
@param[in] value                Unsigned value of the mappings to find.
@returns                        Iterator on enumeration mappings that
                                match \p value, or \c NULL on error.

@prenotnull{enum_field_type}
@prenotnull{name}
@preisenumft{enum_field_type}
@postrefcountsame{enum_field_type}
@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type_enumeration_mapping_iterator *
bt_ctf_field_type_enumeration_find_mappings_by_unsigned_value(
                struct bt_ctf_field_type *enum_field_type,
                uint64_t value);

/**
@brief  Adds a mapping to the @enumft \p enum_field_type which maps the
        name \p name to the signed range \p range_begin (included) to
        \p range_end (included).

Make \p range_begin and \p range_end the same value to add a mapping
to a single value.

The @intft wrapped by \p enum_field_type, as returned by
bt_ctf_field_type_enumeration_get_container_type(), must be
\b signed to use this function.

A mapping in \p enum_field_type can exist with the name \p name.

@param[in] enum_field_type      Enumeration field type to which to add
                                a mapping.
@param[in] name                 Name of the mapping to add (copied
                                on success).
@param[in] range_begin          Beginning of the range of the mapping
                                (included).
@param[in] range_end            End of the range of the mapping
                                (included).
@returns                        0 on success, or a negative value on error.

@prenotnull{enum_field_type}
@prenotnull{name}
@preisenumft{enum_field_type}
@pre The wrapped @intft of \p enum_field_type is signed.
@pre \p range_end is greater than or equal to \p range_begin.
@postrefcountsame{enum_field_type}

@sa bt_ctf_field_type_enumeration_add_mapping_unsigned(): Adds an
        unsigned mapping to a given enumeration field type.
*/
extern int bt_ctf_field_type_enumeration_add_mapping(
                struct bt_ctf_field_type *enum_field_type, const char *name,
                int64_t range_begin, int64_t range_end);

/**
@brief  Adds a mapping to the @enumft \p enum_field_type which maps
        the name \p name to the unsigned
        range \p range_begin (included) to \p range_end (included).

Make \p range_begin and \p range_end the same value to add a mapping
to a single value.

The @intft wrapped by \p enum_field_type, as returned by
bt_ctf_field_type_enumeration_get_container_type(), must be
\b unsigned to use this function.

A mapping in \p enum_field_type can exist with the name \p name.

@param[in] enum_field_type      Enumeration field type to which to add
                                a mapping.
@param[in] name                 Name of the mapping to add (copied
                                on success).
@param[in] range_begin          Beginning of the range of the mapping
                                (included).
@param[in] range_end            End of the range of the mapping
                                (included).
@returns                        0 on success, or a negative value on error.

@prenotnull{enum_field_type}
@prenotnull{name}
@preisenumft{enum_field_type}
@pre The wrapped @intft of \p enum_field_type is unsigned.
@pre \p range_end is greater than or equal to \p range_begin.
@postrefcountsame{enum_field_type}

@sa bt_ctf_field_type_enumeration_add_mapping(): Adds a signed
        mapping to a given enumeration field type.
*/
extern int bt_ctf_field_type_enumeration_add_mapping_unsigned(
                struct bt_ctf_field_type *enum_field_type, const char *name,
                uint64_t range_begin, uint64_t range_end);

/** @} */

/**
@defgroup ctfirenummappingiter CTF IR enumeration mapping iterator
@ingroup ctfirfieldtypes
@brief CTF IR enumeration mapping iterator.
@struct bt_ctf_field_type_enumeration_mapping_iterator

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>enumeration mapping iterator</em></strong> is an
iterator on @enumft mappings.

You can obtain an enumeration mapping iterator using one of the mapping
query functions:bt_ctf_field_type_enumeration_find_mappings_by_unsigned_value(),
bt_ctf_field_type_enumeration_find_mappings_by_signed_value(), and
bt_ctf_field_type_enumeration_find_mappings_by_name().

You can query an enumeration mapping's <strong>name</strong> from an iterator
using bt_ctf_field_type_enumeration_mapping_iterator_get_name().

You can also query an enumeration mapping's <strong>value range</strong>
from an iterator with
bt_ctf_field_type_enumeration_mapping_iterator_get_signed() or
bt_ctf_field_type_enumeration_mapping_iterator_get_unsigned(), depending on
the signedness of the wrapped @intft.

An <strong><em>enumeration mapping iterator</em></strong>'s position can
be advanced using
bt_ctf_field_type_enumeration_mapping_iterator_next().

@sa ctfirenumfieldtype
@sa ctfirenumfield

@addtogroup ctfirenummappingiter
@{
*/

/**
@brief  Returns the name of the @enumft mapping pointed to by
        \p iter.

On success, the returned \p mapping_name is valid as long as a reference
is held on \p iter and its position is not changed.

@param[in] iter                 Enumeration mapping iterator.
@param[out] mapping_name        Returned name of the mapping pointed to
                                by \p iter.
@returns                        0 on success, or a negative value on error.

@prenotnull{iter}
@prenotnull{mapping_name}
@postrefcountsame{iter}
*/
extern int bt_ctf_field_type_enumeration_mapping_iterator_get_name(
                struct bt_ctf_field_type_enumeration_mapping_iterator *iter,
                const char **mapping_name);

/**
@brief  Returns the range of the signed @enumft mapping pointed to by
        \p iter.

The @intft wrapped by \p enum_field_type, as returned by
bt_ctf_field_type_enumeration_get_container_type(), must be
\b signed to use this function.

@param[in] iter                 Enumeration mapping iterator.
@param[out] range_begin         Returned beginning of the range
                                (included) of the mapping pointed to by
                                \p iter.
@param[out] range_end           Returned end of the range (included) of
                                the mapping pointed to by \p iter.
@returns                        0 on success, or a negative value on error.

@prenotnull{iter}
@prenotnull{range_begin}
@prenotnull{range_end}
@postrefcountsame{iter}

@sa bt_ctf_field_type_enumeration_mapping_iterator_get_unsigned(): Returns
        the range of the unsigned enumeration mapping pointed by an enumeration
        mapping iterator.
*/
extern int bt_ctf_field_type_enumeration_mapping_iterator_get_signed(
                struct bt_ctf_field_type_enumeration_mapping_iterator *iter,
                const char **mapping_name,
                int64_t *range_begin, int64_t *range_end);

/**
@brief  Returns the range of the unsigned @enumft mapping pointed to by
        \p iter.

The @intft wrapped by \p enum_field_type, as returned by
bt_ctf_field_type_enumeration_get_container_type(), must be
\b unsigned to use this function.

@param[in] iter                 Enumeration mapping iterator.
@param[out] range_begin         Returned beginning of the range
                                (included) of the mapping pointed to by
                                \p iter.
@param[out] range_end           Returned end of the range (included) of
                                the mapping pointed to by \p iter.
@returns                        0 on success, or a negative value on error.

@prenotnull{iter}
@prenotnull{range_begin}
@prenotnull{range_end}
@postrefcountsame{iter}

@sa bt_ctf_field_type_enumeration_mapping_iterator_get_signed(): Returns the
        range of the signed enumeration mapping pointed by an enumeration
        mapping iterator.
*/
extern int bt_ctf_field_type_enumeration_mapping_iterator_get_unsigned(
                struct bt_ctf_field_type_enumeration_mapping_iterator *iter,
                const char **mapping_name,
                uint64_t *range_begin, uint64_t *range_end);

/**
@brief  Advance the position of the @enumiter \p iter.

@param[in] iter                 Enumeration mapping iterator.
@returns                        0 on success, or a negative value on error or
                                end of mappings set.

@prenotnull{iter}
@postrefcountsame{iter}
*/
extern int bt_ctf_field_type_enumeration_mapping_iterator_next(
                struct bt_ctf_field_type_enumeration_mapping_iterator *iter);

/** @} */

/**
@defgroup ctfirstringfieldtype CTF IR string field type
@ingroup ctfirfieldtypes
@brief CTF IR string field type.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>string field type</em></strong> is a field type that
you can use to create concrete @stringfields.

You can create a string field type
with bt_ctf_field_type_string_create().

A string field type has only one property: the \b encoding of its
described @stringfields. By default, the encoding of the string fields
described by a string field type is #BT_CTF_STRING_ENCODING_UTF8. You
can set the encoding of the string fields described by a string field
type with bt_ctf_field_type_string_set_encoding().

@sa ctfirstringfield
@sa ctfirfieldtypes

@addtogroup ctfirstringfieldtype
@{
*/

/**
@brief  Creates a default @stringft.

@returns        Created string field type, or \c NULL on error.

@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_string_create(void);

/**
@brief  Returns the encoding of the @stringfields described by
        the @stringft \p string_field_type.

@param[in] string_field_type    String field type which describes the
                                string fields of which to get the
                                encoding.
@returns                        Encoding of the string
                                fields described by \p string_field_type,
                                or #BT_CTF_STRING_ENCODING_UNKNOWN on
                                error.

@prenotnull{string_field_type}
@preisstringft{string_field_type}
@postrefcountsame{string_field_type}

@sa bt_ctf_field_type_string_set_encoding(): Sets the encoding
        of the string fields described by a given string field type.
*/
extern enum bt_ctf_string_encoding bt_ctf_field_type_string_get_encoding(
                struct bt_ctf_field_type *string_field_type);

/**
@brief  Sets the encoding of the @stringfields described by the
        @stringft \p string_field_type to \p encoding.

@param[in] string_field_type    String field type which describes the
                                string fields of which to set the
                                encoding.
@param[in] encoding             Encoding of the string fields described
                                by \p string_field_type.
@returns                        0 on success, or a negative value on error.

@prenotnull{string_field_type}
@preisstringft{string_field_type}
@prehot{string_field_type}
@pre \p encoding is #BT_CTF_STRING_ENCODING_ASCII or
        #BT_CTF_STRING_ENCODING_UTF8.
@postrefcountsame{string_field_type}

@sa bt_ctf_field_type_string_get_encoding(): Returns the encoding of
        the string fields described by a given string field type.
*/
extern int bt_ctf_field_type_string_set_encoding(
                struct bt_ctf_field_type *string_field_type,
                enum bt_ctf_string_encoding encoding);

/** @} */

/**
@defgroup ctfirstructfieldtype CTF IR structure field type
@ingroup ctfirfieldtypes
@brief CTF IR structure field type.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>structure field type</em></strong> is
a field type that you can use to create concrete @structfields.

You can create a structure field type
with bt_ctf_field_type_structure_create(). This function creates
an empty structure field type, with no fields.

You can add a field to a structure field type with
bt_ctf_field_type_structure_add_field(). Two fields in a structure
field type cannot have the same name.

You can set the \em minimum alignment of the structure fields described
by a structure field type with the common
bt_ctf_field_type_set_alignment() function. The \em effective alignment
of the structure fields described by a structure field type, as per
<a href="http://diamon.org/ctf/">CTF</a>, is the \em maximum value amongst
the effective alignments of all its fields. Note that the effective
alignment of @varfields is always 1.

You can set the byte order of <em>all the contained fields</em>,
recursively, of a structure field type with the common
bt_ctf_field_type_set_byte_order() function.

@sa ctfirstructfield
@sa ctfirfieldtypes

@addtogroup ctfirstructfieldtype
@{
*/

/**
@brief  Creates a default, empty @structft.

@returns                        Created structure field type,
                                or \c NULL on error.

@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_structure_create(void);

/**
@brief  Returns the number of fields contained in the
        @structft \p struct_field_type.

@param[in] struct_field_type    Structure field type of which to get
                                the number of contained fields.
@returns                        Number of fields contained in
                                \p struct_field_type, or a negative
                                value on error.

@prenotnull{struct_field_type}
@preisstructft{struct_field_type}
@postrefcountsame{struct_field_type}
*/
extern int bt_ctf_field_type_structure_get_field_count(
                struct bt_ctf_field_type *struct_field_type);

/**
@brief  Returns the field of the @structft \p struct_field_type
        at index \p index.

On success, the field's type is placed in \p *field_type if
\p field_type is not \c NULL. The field's name is placed in
\p *field_name if \p field_name is not \c NULL.
\p struct_field_type remains the sole owner of \p *field_name.

@param[in] struct_field_type    Structure field type of which to get
                                the field at index \p index.
@param[out] field_name          Returned name of the field at index
                                \p index (can be \c NULL).
@param[out] field_type          Returned field type of the field
                                at index \p index (can be \c NULL).
­@param[in] index              Index of the field to get from
                                \p struct_field_type.
@returns                        0 on success, or a negative value on error.

@prenotnull{struct_field_type}
@preisstructft{struct_field_type}
@pre \p index is lesser than the number of fields contained in the
        structure field type \p struct_field_type (see
        bt_ctf_field_type_structure_get_field_count()).
@postrefcountsame{struct_field_type}
@post <strong>On success</strong>, the returned field's type is placed
        in \p *field_type and its reference count is incremented.

@sa bt_ctf_field_type_structure_get_field_type_by_name(): Finds a
        structure field type's field by name.
*/
extern int bt_ctf_field_type_structure_get_field(
                struct bt_ctf_field_type *struct_field_type,
                const char **field_name, struct bt_ctf_field_type **field_type,
                int index);

/**
@brief  Returns the type of the field named \p field_name found in
        the @structft \p struct_field_type.

@param[in] struct_field_type    Structure field type of which to get
                                a field's type.
@param[in] field_name           Name of the field to find.
@returns                        Type of the field named \p field_name in
                                \p struct_field_type, or
                                \c NULL on error.

@prenotnull{struct_field_type}
@prenotnull{field_name}
@preisstructft{struct_field_type}
@postrefcountsame{struct_field_type}
@postsuccessrefcountretinc

@sa bt_ctf_field_type_structure_get_field(): Finds a
        structure field type's field by index.
*/
extern
struct bt_ctf_field_type *bt_ctf_field_type_structure_get_field_type_by_name(
                struct bt_ctf_field_type *struct_field_type,
                const char *field_name);

/**
@brief  Adds a field named \p field_name with the @ft
        \p field_type to the @structft \p struct_field_type.

On success, \p field_type becomes the child of \p struct_field_type.

This function adds the new field after the current last field of
\p struct_field_type (append mode).

You \em cannot add a field named \p field_name if there's already a
field named \p field_name in \p struct_field_type.

@param[in] struct_field_type    Structure field type to which to add
                                a new field.
@param[in] field_type           Field type of the field to add to
                                \p struct_field_type.
@param[in] field_name           Name of the field to add to
                                \p struct_field_type
                                (copied on success).
@returns                        0 on success, or a negative value on error.

@prenotnull{struct_field_type}
@prenotnull{field_type}
@prenotnull{field_name}
@preisstructft{struct_field_type}
@pre \p field_type is not and does not contain \p struct_field_type,
        recursively, as a field's type.
@prehot{struct_field_type}
@postrefcountsame{struct_field_type}
@postsuccessrefcountinc{field_type}
*/
extern int bt_ctf_field_type_structure_add_field(
                struct bt_ctf_field_type *struct_field_type,
                struct bt_ctf_field_type *field_type,
                const char *field_name);

/** @} */

/**
@defgroup ctfirarrayfieldtype CTF IR array field type
@ingroup ctfirfieldtypes
@brief CTF IR array field type.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>array field type</em></strong> is a field type that
you can use to create concrete @arrayfields.

You can create an array field type
with bt_ctf_field_type_array_create(). This function needs
the @ft of the fields contained by the array fields described by the
array field type to create.

@sa ctfirarrayfield
@sa ctfirfieldtypes

@addtogroup ctfirarrayfieldtype
@{
*/

/**
@brief  Creates a default @arrayft with
        \p element_field_type as the field type of the fields contained
        in its described @arrayfields of length \p length.

@param[in] element_field_type   Field type of the fields contained in
                                the array fields described by the
                                created array field type.
@param[in] length               Length of the array fields described by
                                the created array field type.
@returns                        Created array field type, or
                                \c NULL on error.

@prenotnull{element_field_type}
@postsuccessrefcountinc{element_field_type}
@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_array_create(
                struct bt_ctf_field_type *element_field_type,
                unsigned int length);

/**
@brief  Returns the @ft of the @fields contained in
        the @arrayfields described by the @arrayft \p array_field_type.

@param[in] array_field_type     Array field type of which to get
                                the type of the fields contained in its
                                described array fields.
@returns                        Type of the fields contained in the
                                array fields described by
                                \p array_field_type, or \c NULL
                                on error.

@prenotnull{array_field_type}
@preisarrayft{array_field_type}
@postrefcountsame{array_field_type}
@postsuccessrefcountretinc
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_array_get_element_type(
                struct bt_ctf_field_type *array_field_type);

/**
@brief  Returns the number of @fields contained in the
        @arrayfields described by the @arrayft \p array_field_type.

@param[in] array_field_type     Array field type of which to get
                                the number of fields contained in its
                                described array fields.
@returns                        Number of fields contained in the
                                array fields described by
                                \p array_field_type, or a negative value
                                on error.

@prenotnull{array_field_type}
@preisarrayft{array_field_type}
@postrefcountsame{array_field_type}
*/
extern int64_t bt_ctf_field_type_array_get_length(
                struct bt_ctf_field_type *array_field_type);

/** @} */

/**
@defgroup ctfirseqfieldtype CTF IR sequence field type
@ingroup ctfirfieldtypes
@brief CTF IR sequence field type.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>sequence field type</em></strong> is
a field type that you can use to create concrete @seqfields.

You can create a sequence field type with
bt_ctf_field_type_sequence_create(). This function needs the @ft
of the fields contained by the sequence fields described by the created
sequence field type. This function also needs the length name of the
sequence field type to create. The length name is used to automatically
resolve the length's field type. See \ref ctfirfieldtypes to learn more
about the automatic resolving.

@sa ctfirseqfield
@sa ctfirfieldtypes

@addtogroup ctfirseqfieldtype
@{
*/

/**
@brief  Creates a default @seqft with \p element_field_type as the
        @ft of the @fields contained in its described @seqfields
        with the length name \p length_name.

\p length_name can be an absolute or relative reference. See
<a href="http://diamon.org/ctf/">CTF</a> for more details.

@param[in] element_field_type   Field type of the fields contained in
                                the sequence fields described by the
                                created sequence field type.
@param[in] length_name          Length name (copied on success).
@returns                        Created array field type, or
                                \c NULL on error.

@prenotnull{element_field_type}
@prenotnull{length_name}
@postsuccessrefcountinc{element_field_type}
@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_sequence_create(
                struct bt_ctf_field_type *element_field_type,
                const char *length_name);

/**
@brief  Returns the @ft of the @fields contained in the @seqft
        described by the @seqft \p sequence_field_type.

@param[in] sequence_field_type  Sequence field type of which to get
                                the type of the fields contained in its
                                described sequence fields.
@returns                        Type of the fields contained in the
                                sequence fields described by
                                \p sequence_field_type, or \c NULL
                                on error.

@prenotnull{sequence_field_type}
@preisseqft{sequence_field_type}
@postrefcountsame{sequence_field_type}
@postsuccessrefcountretinc
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_sequence_get_element_type(
                struct bt_ctf_field_type *sequence_field_type);

/**
@brief  Returns the length name of the @seqft \p sequence_field_type.

On success, \p sequence_field_type remains the sole owner of
the returned string.

@param[in] sequence_field_type  Sequence field type of which to get the
                                length name.
@returns                        Length name of \p sequence_field_type,
                                or \c NULL on error.

@prenotnull{sequence_field_type}
@preisseqft{sequence_field_type}

@sa bt_ctf_field_type_sequence_get_length_field_path(): Returns the
        length's CTF IR field path of a given sequence field type.
*/
extern const char *bt_ctf_field_type_sequence_get_length_field_name(
                struct bt_ctf_field_type *sequence_field_type);

/**
@brief  Returns the length's CTF IR field path of the @seqft
        \p sequence_field_type.

The length's field path of a sequence field type is set when automatic
resolving is performed (see \ref ctfirfieldtypes).

@param[in] sequence_field_type  Sequence field type of which to get the
                                length's field path.
@returns                        Length's field path of
                                \p sequence_field_type, or
                                \c NULL if the length's field path is
                                not set yet is not set or on error.

@prenotnull{sequence_field_type}
@preisseqft{sequence_field_type}
@postsuccessrefcountretinc

@sa bt_ctf_field_type_sequence_get_length_field_name(): Returns the
        length's name of a given sequence field type.
*/
extern struct bt_ctf_field_path *bt_ctf_field_type_sequence_get_length_field_path(
                struct bt_ctf_field_type *sequence_field_type);

/** @} */

/**
@defgroup ctfirvarfieldtype CTF IR variant field type
@ingroup ctfirfieldtypes
@brief CTF IR variant field type.

@code
#include <babeltrace/ctf-ir/field-types.h>
@endcode

A CTF IR <strong><em>variant field type</em></strong> is
a field type that you can use to create concrete @varfields.

You can create a variant field type with
bt_ctf_field_type_variant_create(). This function expects you to pass
both the tag's @enumft and the tag name of the variant field type to
create. The tag's field type is optional, as the Babeltrace system can
automatically resolve it using the tag name. You can leave the tag name
to \c NULL initially, and set it later with
bt_ctf_field_type_variant_set_tag_name(). The tag name must be set when
the variant field type is frozen. See \ref ctfirfieldtypes to learn more
about the automatic resolving and the conditions under which a field
type can be frozen.

You can add a field to a variant field type with
bt_ctf_field_type_variant_add_field(). All the field names of a
variant field type \em must exist as mapping names in its tag's @enumft.

The effective alignment of the @varfields described by a
variant field type is always 1, but the individual fields of a
@varfield can have custom alignments.

You can set the byte order of <em>all the contained fields</em>,
recursively, of a variant field type with the common
bt_ctf_field_type_set_byte_order() function.

@sa ctfirvarfield
@sa ctfirfieldtypes

@addtogroup ctfirvarfieldtype
@{
*/

/**
@brief  Creates a default, empty @varft with the tag's @enumft
        \p tag_field_type and the tag name \p tag_name.

\p tag_field_type can be \c NULL; the tag's field type can be
automatically resolved from the variant field type's tag name (see
\ref ctfirfieldtypes). If \p tag_name is \c NULL, it \em must be set
with bt_ctf_field_type_variant_set_tag_name() \em before the variant
field type is frozen.

\p tag_name can be an absolute or relative reference. See
<a href="http://diamon.org/ctf/">CTF</a> for more details.

@param[in] tag_field_type       Tag's enumeration field type
                                (can be \c NULL).
@param[in] tag_name             Tag name (copied on success,
                                can be \c NULL).
@returns                        Created variant field type, or
                                \c NULL on error.

@pre \p tag_field_type is an enumeration field type or \c NULL.
@post <strong>On success, if \p tag_field_type is not \c NULL</strong>,
        its reference count is incremented.
@postsuccessrefcountret1
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_variant_create(
                struct bt_ctf_field_type *tag_field_type,
                const char *tag_name);

/**
@brief  Returns the tag's @enumft of the @varft \p variant_field_type.

@param[in] variant_field_type   Variant field type of which to get
                                the tag's enumeration field type.
@returns                        Tag's enumeration field type of
                                \p variant_field_type, or \c NULL if the
                                tag's field type is not set or on
                                error.

@prenotnull{variant_field_type}
@preisvarft{variant_field_type}
@postrefcountsame{variant_field_type}
@postsuccessrefcountretinc
*/
extern struct bt_ctf_field_type *bt_ctf_field_type_variant_get_tag_type(
                struct bt_ctf_field_type *variant_field_type);

/**
@brief  Returns the tag name of the @varft \p variant_field_type.

On success, \p variant_field_type remains the sole owner of
the returned string.

@param[in] variant_field_type   Variant field type of which to get the
                                tag name.
@returns                        Tag name of \p variant_field_type, or
                                \c NULL if the tag name is not set or
                                on error.

@prenotnull{variant_field_type}
@preisvarft{variant_field_type}

@sa bt_ctf_field_type_variant_set_tag_name(): Sets the tag name of
        a given variant field type.
@sa bt_ctf_field_type_variant_get_tag_field_path(): Returns the tag's
        CTF IR field path of a given variant field type.
*/
extern const char *bt_ctf_field_type_variant_get_tag_name(
                struct bt_ctf_field_type *variant_field_type);

/**
@brief  Sets the tag name of the @varft \p variant_field_type.

\p tag_name can be an absolute or relative reference. See
<a href="http://diamon.org/ctf/">CTF</a> for more details.

@param[in] variant_field_type   Variant field type of which to set
                                the tag name.
@param[in] tag_name             Tag name of \p variant_field_type
                                (copied on success).
@returns                        0 on success, or a negative value on error.

@prenotnull{variant_field_type}
@prenotnull{name}
@prehot{variant_field_type}
@postrefcountsame{variant_field_type}

@sa bt_ctf_field_type_variant_get_tag_name(): Returns the tag name of
        a given variant field type.
*/
extern int bt_ctf_field_type_variant_set_tag_name(
                struct bt_ctf_field_type *variant_field_type,
                const char *tag_name);

/**
@brief  Returns the tag's CTF IR field path of the @varft
        \p variant_field_type.

The tag's field path of a variant field type is set when automatic
resolving is performed (see \ref ctfirfieldtypes).

@param[in] variant_field_type   Variant field type of which to get the
                                tag's field path.
@returns                        Tag's field path of
                                \p variant_field_type, or
                                \c NULL if the tag's field path is not
                                set yet is not set or on error.

@prenotnull{variant_field_type}
@preisvarft{variant_field_type}
@postsuccessrefcountretinc

@sa bt_ctf_field_type_variant_get_tag_name(): Returns the tag's
        name of a given variant field type.
*/
extern struct bt_ctf_field_path *bt_ctf_field_type_variant_get_tag_field_path(
                struct bt_ctf_field_type *variant_field_type);

/**
@brief  Returns the number of fields (choices) contained in the @varft
        \p variant_field_type.

@param[in] variant_field_type   Variant field type of which to get
                                the number of contained fields.
@returns                        Number of fields contained in
                                \p variant_field_type, or a negative
                                value on error.

@prenotnull{variant_field_type}
@preisvarft{variant_field_type}
@postrefcountsame{variant_field_type}
*/
extern int bt_ctf_field_type_variant_get_field_count(
                struct bt_ctf_field_type *variant_field_type);

/**
@brief  Returns the field (choice) of the @varft \p variant_field_type
        at index \p index.

On success, the field's type is placed in \p *field_type if
\p field_type is not \c NULL. The field's name is placed in
\p *field_name if \p field_name is not \c NULL.
\p variant_field_type remains the sole owner of \p *field_name.

@param[in] variant_field_type   Variant field type of which to get
                                the field at index \p index.
@param[out] field_name          Returned name of the field at index
                                \p index (can be \c NULL).
@param[out] field_type          Returned field type of the field
                                at index \p index (can be \c NULL).
­@param[in] index              Index of the field to get from
                                \p variant_field_type.
@returns                        0 on success, or a negative value on error.

@prenotnull{variant_field_type}
@preisvarft{variant_field_type}
@pre \p index is lesser than the number of fields contained in the
        variant field type \p variant_field_type (see
        bt_ctf_field_type_variant_get_field_count()).
@postrefcountsame{variant_field_type}
@post <strong>On success</strong>, the returned field's type is placed
        in \p *field_type and its reference count is incremented.

@sa bt_ctf_field_type_variant_get_field_type_by_name(): Finds a variant
        field type's field by name.
@sa bt_ctf_field_type_variant_get_field_type_from_tag(): Finds a variant
        field type's field by current tag value.
*/
extern int bt_ctf_field_type_variant_get_field(
                struct bt_ctf_field_type *variant_field_type,
                const char **field_name,
                struct bt_ctf_field_type **field_type, int index);

/**
@brief  Returns the type of the field (choice) named \p field_name
        found in the @varft \p variant_field_type.

@param[in] variant_field_type   Variant field type of which to get
                                a field's type.
@param[in] field_name           Name of the field to find.
@returns                        Type of the field named \p field_name in
                                \p variant_field_type, or
                                \c NULL on error.

@prenotnull{variant_field_type}
@prenotnull{field_name}
@preisvarft{variant_field_type}
@postrefcountsame{variant_field_type}
@postsuccessrefcountretinc

@sa bt_ctf_field_type_variant_get_field(): Finds a variant field type's
        field by index.
@sa bt_ctf_field_type_variant_get_field_type_from_tag(): Finds a variant
        field type's field by current tag value.
*/
extern
struct bt_ctf_field_type *bt_ctf_field_type_variant_get_field_type_by_name(
                struct bt_ctf_field_type *variant_field_type,
                const char *field_name);

/**
@brief  Returns the type of the field (choice) selected by the value of
        the @enumfield \p tag_field in the @varft \p variant_field_type.

\p tag_field is the current tag value.

The field type of \p tag_field, as returned by bt_ctf_field_get_type(),
\em must be equivalent to the field type returned by
bt_ctf_field_type_variant_get_tag_type() for \p variant_field_type.

@param[in] variant_field_type   Variant field type of which to get
                                a field's type.
@param[in] tag_field            Current tag value (variant field type's
                                selector).
@returns                        Type of the field selected by
                                \p tag_field in \p variant_field_type,
                                or \c NULL on error.

@prenotnull{variant_field_type}
@prenotnull{tag_field}
@preisvarft{variant_field_type}
@preisenumfield{tag_field}
@postrefcountsame{variant_field_type}
@postrefcountsame{tag_field}
@postsuccessrefcountretinc

@sa bt_ctf_field_type_variant_get_field(): Finds a variant field type's
        field by index.
@sa bt_ctf_field_type_variant_get_field_type_by_name(): Finds a variant
        field type's field by name.
*/
extern
struct bt_ctf_field_type *bt_ctf_field_type_variant_get_field_type_from_tag(
                struct bt_ctf_field_type *variant_field_type,
                struct bt_ctf_field *tag_field);

/**
@brief  Adds a field (a choice) named \p field_name with the @ft
        \p field_type to the @varft \p variant_field_type.

On success, \p field_type becomes the child of \p variant_field_type.

You \em cannot add a field named \p field_name if there's already a
field named \p field_name in \p variant_field_type.

\p field_name \em must name an existing mapping in the tag's
enumeration field type of \p variant_field_type.

@param[in] variant_field_type   Variant field type to which to add
                                a new field.
@param[in] field_type           Field type of the field to add to
                                \p variant_field_type.
@param[in] field_name           Name of the field to add to
                                \p variant_field_type
                                (copied on success).
@returns                        0 on success, or a negative value on error.

@prenotnull{variant_field_type}
@prenotnull{field_type}
@prenotnull{field_name}
@preisvarft{variant_field_type}
@pre \p field_type is not and does not contain \p variant_field_type,
        recursively, as a field's type.
@prehot{variant_field_type}
@postrefcountsame{variant_field_type}
@postsuccessrefcountinc{field_type}
*/
extern int bt_ctf_field_type_variant_add_field(
                struct bt_ctf_field_type *variant_field_type,
                struct bt_ctf_field_type *field_type,
                const char *field_name);

/** @} */

#ifdef __cplusplus
}
#endif

#endif /* BABELTRACE_CTF_IR_FIELD_TYPES_H */