girepository/gistructinfo.c

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
 * GObject introspection: Struct implementation
 *
 * Copyright (C) 2005 Matthias Clasen
 * Copyright (C) 2008,2009 Red Hat, Inc.
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 *
 * 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.
 */

#include "config.h"

#include <string.h>

#include <glib.h>

#include <girepository/girepository.h>
#include "gibaseinfo-private.h"
#include "girepository-private.h"
#include "gitypelib-internal.h"
#include "gistructinfo.h"

/**
 * GIStructInfo:
 *
 * `GIStructInfo` represents a generic C structure type.
 *
 * A structure has methods and fields.
 *
 * Since: 2.80
 */

/**
 * gi_struct_info_get_n_fields:
 * @info: a #GIStructInfo
 *
 * Obtain the number of fields this structure has.
 *
 * Returns: number of fields
 * Since: 2.80
 */
unsigned int
gi_struct_info_get_n_fields (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->n_fields;
}

/**
 * gi_struct_info_get_field_offset:
 * @info: a #GIStructInfo
 * @n: index of queried field
 *
 * Obtain the offset of the specified field.
 *
 * Returns: field offset, in bytes
 * Since: 2.80
 */
static size_t
gi_struct_get_field_offset (GIStructInfo *info,
                            uint16_t        n)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  Header *header = (Header *)rinfo->typelib->data;
  size_t offset = rinfo->offset + header->struct_blob_size;
  FieldBlob *field_blob;

  for (uint16_t i = 0; i < n; i++)
    {
      field_blob = (FieldBlob *)&rinfo->typelib->data[offset];
      offset += header->field_blob_size;
      if (field_blob->has_embedded_type)
        offset += header->callback_blob_size;
    }

  return offset;
}

/**
 * gi_struct_info_get_field:
 * @info: a #GIStructInfo
 * @n: a field index
 *
 * Obtain the type information for field with specified index.
 *
 * Returns: (transfer full): The [class@GIRepository.FieldInfo]. Free it with
 *   [method@GIRepository.BaseInfo.unref] when done.
 * Since: 2.80
 */
GIFieldInfo *
gi_struct_info_get_field (GIStructInfo *info,
                          unsigned int  n)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;

  g_return_val_if_fail (n <= G_MAXUINT16, NULL);

  return (GIFieldInfo *) gi_base_info_new (GI_INFO_TYPE_FIELD, (GIBaseInfo*)info, rinfo->typelib,
                                           gi_struct_get_field_offset (info, n));
}

/**
 * gi_struct_info_find_field:
 * @info: a #GIStructInfo
 * @name: a field name
 *
 * Obtain the type information for field named @name.
 *
 * Returns: (transfer full) (nullable): The [class@GIRepository.FieldInfo], or
 *   `NULL` if not found. Free it with [method@GIRepository.BaseInfo.unref] when
 *   done.
 * Since: 2.80
 */
GIFieldInfo *
gi_struct_info_find_field (GIStructInfo *info,
                           const char   *name)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];
  Header *header = (Header *)rinfo->typelib->data;
  size_t offset = rinfo->offset + header->struct_blob_size;

  for (size_t i = 0; i < blob->n_fields; i++)
    {
      FieldBlob *field_blob = (FieldBlob *)&rinfo->typelib->data[offset];
      const char *fname = (const char *)&rinfo->typelib->data[field_blob->name];

      if (strcmp (name, fname) == 0)
        {
          return (GIFieldInfo *) gi_base_info_new (GI_INFO_TYPE_FIELD,
                                                   (GIBaseInfo* )info,
                                                   rinfo->typelib,
                                                   offset);
        }

      offset += header->field_blob_size;
      if (field_blob->has_embedded_type)
        offset += header->callback_blob_size;
    }

  return NULL;
}

/**
 * gi_struct_info_get_n_methods:
 * @info: a #GIStructInfo
 *
 * Obtain the number of methods this structure has.
 *
 * Returns: number of methods
 * Since: 2.80
 */
unsigned int
gi_struct_info_get_n_methods (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->n_methods;
}

/**
 * gi_struct_info_get_method:
 * @info: a #GIStructInfo
 * @n: a method index
 *
 * Obtain the type information for method with specified index.
 *
 * Returns: (transfer full): The [class@GIRepository.FunctionInfo]. Free it with
 *   [method@GIRepository.BaseInfo.unref] when done.
 * Since: 2.80
 */
GIFunctionInfo *
gi_struct_info_get_method (GIStructInfo *info,
                           unsigned int  n)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];
  Header *header = (Header *)rinfo->typelib->data;
  size_t offset;

  g_return_val_if_fail (n <= G_MAXUINT16, NULL);

  offset = gi_struct_get_field_offset (info, blob->n_fields) + n * header->function_blob_size;
  return (GIFunctionInfo *) gi_base_info_new (GI_INFO_TYPE_FUNCTION, (GIBaseInfo*)info,
                                              rinfo->typelib, offset);
}

/**
 * gi_struct_info_find_method:
 * @info: a #GIStructInfo
 * @name: a method name
 *
 * Obtain the type information for method named @name.
 *
 * Returns: (transfer full) (nullable): The [class@GIRepository.FunctionInfo],
 *   or `NULL` if none was found. Free it with
 *   [method@GIRepository.BaseInfo.unref] when done.
 * Since: 2.80
 */
GIFunctionInfo *
gi_struct_info_find_method (GIStructInfo *info,
                            const char   *name)
{
  size_t offset;
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  offset = gi_struct_get_field_offset (info, blob->n_fields);
  return gi_base_info_find_method ((GIBaseInfo*)info, offset, blob->n_methods, name);
}

/**
 * gi_struct_info_get_size:
 * @info: a #GIStructInfo
 *
 * Obtain the total size of the structure.
 *
 * Returns: size of the structure, in bytes
 * Since: 2.80
 */
size_t
gi_struct_info_get_size (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->size;
}

/**
 * gi_struct_info_get_alignment:
 * @info: a #GIStructInfo
 *
 * Obtain the required alignment of the structure.
 *
 * Returns: required alignment, in bytes
 * Since: 2.80
 */
size_t
gi_struct_info_get_alignment (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->alignment;
}

/**
 * gi_struct_info_is_foreign:
 * @info: a #GIStructInfo
 *
 * Gets whether the structure is foreign, i.e. if it’s expected to be overridden
 * by a native language binding instead of relying of introspected bindings.
 *
 * Returns: `TRUE` if the structure is foreign
 * Since: 2.80
 */
gboolean
gi_struct_info_is_foreign (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->foreign;
}

/**
 * gi_struct_info_is_gtype_struct:
 * @info: a #GIStructInfo
 *
 * Return true if this structure represents the ‘class structure’ for some
 * [class@GObject.Object] or `GInterface`.
 *
 * This function is mainly useful to hide this kind of structure from generated
 * public APIs.
 *
 * Returns: `TRUE` if this is a class struct, `FALSE` otherwise
 * Since: 2.80
 */
gboolean
gi_struct_info_is_gtype_struct (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  return blob->is_gtype_struct;
}

/**
 * gi_struct_info_get_copy_function_name:
 * @info: a struct information blob
 *
 * Retrieves the name of the copy function for @info, if any is set.
 *
 * Returns: (transfer none) (nullable): the name of the copy function, or `NULL`
 *   if the structure has no copy function
 * Since: 2.80
 */
const char *
gi_struct_info_get_copy_function_name (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob;

  g_return_val_if_fail (info != NULL, NULL);
  g_return_val_if_fail (GI_IS_STRUCT_INFO (info), NULL);

  blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  if (blob->copy_func)
    return gi_typelib_get_string (rinfo->typelib, blob->copy_func);

  return NULL;
}

/**
 * gi_struct_info_get_free_function_name:
 * @info: a struct information blob
 *
 * Retrieves the name of the free function for @info, if any is set.
 *
 * Returns: (transfer none) (nullable): the name of the free function, or `NULL`
 *   if the structure has no free function
 * Since: 2.80
 */
const char *
gi_struct_info_get_free_function_name (GIStructInfo *info)
{
  GIRealInfo *rinfo = (GIRealInfo *)info;
  StructBlob *blob;

  g_return_val_if_fail (info != NULL, NULL);
  g_return_val_if_fail (GI_IS_STRUCT_INFO (info), NULL);

  blob = (StructBlob *)&rinfo->typelib->data[rinfo->offset];

  if (blob->free_func)
    return gi_typelib_get_string (rinfo->typelib, blob->free_func);

  return NULL;
}

void
gi_struct_info_class_init (gpointer g_class,
                           gpointer class_data)
{
  GIBaseInfoClass *info_class = g_class;

  info_class->info_type = GI_INFO_TYPE_STRUCT;
}