(root)/
glib-2.79.0/
girepository/
giconstantinfo.c
       1  /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
       2   * GObject introspection: Constant implementation
       3   *
       4   * Copyright (C) 2005 Matthias Clasen
       5   * Copyright (C) 2008,2009 Red Hat, Inc.
       6   *
       7   * SPDX-License-Identifier: LGPL-2.1-or-later
       8   *
       9   * This library is free software; you can redistribute it and/or
      10   * modify it under the terms of the GNU Lesser General Public
      11   * License as published by the Free Software Foundation; either
      12   * version 2 of the License, or (at your option) any later version.
      13   *
      14   * This library is distributed in the hope that it will be useful,
      15   * but WITHOUT ANY WARRANTY; without even the implied warranty of
      16   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      17   * Lesser General Public License for more details.
      18   *
      19   * You should have received a copy of the GNU Lesser General Public
      20   * License along with this library; if not, write to the
      21   * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
      22   * Boston, MA 02111-1307, USA.
      23   */
      24  
      25  #include "config.h"
      26  
      27  #include <glib.h>
      28  #include <string.h> // memcpy
      29  
      30  #include <girepository/girepository.h>
      31  #include "gibaseinfo-private.h"
      32  #include "girepository-private.h"
      33  #include "gitypelib-internal.h"
      34  #include "giconstantinfo.h"
      35  
      36  /**
      37   * GIConstantInfo:
      38   *
      39   * `GIConstantInfo` represents a constant.
      40   *
      41   * A constant has a type associated – which can be obtained by calling
      42   * [method@GIRepository.ConstantInfo.get_type_info] – and a value – which can be
      43   * obtained by calling [method@GIRepository.ConstantInfo.get_value].
      44   *
      45   * Since: 2.80
      46   */
      47  
      48  /**
      49   * gi_constant_info_get_type_info:
      50   * @info: a #GIConstantInfo
      51   *
      52   * Obtain the type of the constant as a [class@GIRepository.TypeInfo].
      53   *
      54   * Returns: (transfer full): The [class@GIRepository.TypeInfo]. Free the struct
      55   *   by calling [method@GIRepository.BaseInfo.unref] when done.
      56   * Since: 2.80
      57   */
      58  GITypeInfo *
      59  gi_constant_info_get_type_info (GIConstantInfo *info)
      60  {
      61    GIRealInfo *rinfo = (GIRealInfo *)info;
      62  
      63    g_return_val_if_fail (info != NULL, NULL);
      64    g_return_val_if_fail (GI_IS_CONSTANT_INFO (info), NULL);
      65  
      66    return gi_type_info_new ((GIBaseInfo*)info, rinfo->typelib, rinfo->offset + 8);
      67  }
      68  
      69  #define DO_ALIGNED_COPY(dest_addr, src_addr, type) \
      70          memcpy((dest_addr), (src_addr), sizeof(type))
      71  
      72  /**
      73   * gi_constant_info_free_value: (skip)
      74   * @info: a #GIConstantInfo
      75   * @value: the argument
      76   *
      77   * Free the value returned from [method@GIRepository.ConstantInfo.get_value].
      78   *
      79   * Since: 2.80
      80   */
      81  void
      82  gi_constant_info_free_value (GIConstantInfo *info,
      83                               GIArgument     *value)
      84  {
      85    GIRealInfo *rinfo = (GIRealInfo *)info;
      86    ConstantBlob *blob;
      87  
      88    g_return_if_fail (info != NULL);
      89    g_return_if_fail (GI_IS_CONSTANT_INFO (info));
      90  
      91    blob = (ConstantBlob *)&rinfo->typelib->data[rinfo->offset];
      92  
      93    /* FIXME non-basic types ? */
      94    if (blob->type.flags.reserved == 0 && blob->type.flags.reserved2 == 0)
      95      {
      96        if (blob->type.flags.pointer)
      97          g_free (value->v_pointer);
      98      }
      99  }
     100  
     101  /**
     102   * gi_constant_info_get_value: (skip)
     103   * @info: a #GIConstantInfo
     104   * @value: (out caller-allocates): an argument
     105   *
     106   * Obtain the value associated with the `GIConstantInfo` and store it in the
     107   * @value parameter.
     108   *
     109   * @argument needs to be allocated before passing it in.
     110   *
     111   * The size of the constant value (in bytes) stored in @argument will be
     112   * returned.
     113   *
     114   * Free the value with [method@GIRepository.ConstantInfo.free_value].
     115   *
     116   * Returns: size of the constant, in bytes
     117   * Since: 2.80
     118   */
     119  gsize
     120  gi_constant_info_get_value (GIConstantInfo *info,
     121                              GIArgument     *value)
     122  {
     123    GIRealInfo *rinfo = (GIRealInfo *)info;
     124    ConstantBlob *blob;
     125  
     126    g_return_val_if_fail (info != NULL, 0);
     127    g_return_val_if_fail (GI_IS_CONSTANT_INFO (info), 0);
     128  
     129    blob = (ConstantBlob *)&rinfo->typelib->data[rinfo->offset];
     130  
     131    /* FIXME non-basic types ? */
     132    if (blob->type.flags.reserved == 0 && blob->type.flags.reserved2 == 0)
     133      {
     134        if (blob->type.flags.pointer)
     135          {
     136            gsize blob_size = blob->size;
     137  
     138  	  value->v_pointer = g_memdup2 (&rinfo->typelib->data[blob->offset], blob_size);
     139          }
     140        else
     141  	{
     142  	  switch (blob->type.flags.tag)
     143  	    {
     144  	    case GI_TYPE_TAG_BOOLEAN:
     145  	      value->v_boolean = *(gboolean*)&rinfo->typelib->data[blob->offset];
     146  	      break;
     147  	    case GI_TYPE_TAG_INT8:
     148  	      value->v_int8 = *(gint8*)&rinfo->typelib->data[blob->offset];
     149  	      break;
     150  	    case GI_TYPE_TAG_UINT8:
     151  	      value->v_uint8 = *(guint8*)&rinfo->typelib->data[blob->offset];
     152  	      break;
     153  	    case GI_TYPE_TAG_INT16:
     154  	      value->v_int16 = *(gint16*)&rinfo->typelib->data[blob->offset];
     155  	      break;
     156  	    case GI_TYPE_TAG_UINT16:
     157  	      value->v_uint16 = *(guint16*)&rinfo->typelib->data[blob->offset];
     158  	      break;
     159  	    case GI_TYPE_TAG_INT32:
     160  	      value->v_int32 = *(gint32*)&rinfo->typelib->data[blob->offset];
     161  	      break;
     162  	    case GI_TYPE_TAG_UINT32:
     163  	      value->v_uint32 = *(guint32*)&rinfo->typelib->data[blob->offset];
     164  	      break;
     165  	    case GI_TYPE_TAG_INT64:
     166  	      DO_ALIGNED_COPY(&value->v_int64, &rinfo->typelib->data[blob->offset], gint64);
     167  	      break;
     168  	    case GI_TYPE_TAG_UINT64:
     169  	      DO_ALIGNED_COPY(&value->v_uint64, &rinfo->typelib->data[blob->offset], guint64);
     170  	      break;
     171  	    case GI_TYPE_TAG_FLOAT:
     172  	      DO_ALIGNED_COPY(&value->v_float, &rinfo->typelib->data[blob->offset], gfloat);
     173  	      break;
     174  	    case GI_TYPE_TAG_DOUBLE:
     175  	      DO_ALIGNED_COPY(&value->v_double, &rinfo->typelib->data[blob->offset], gdouble);
     176  	      break;
     177  	    default:
     178  	      g_assert_not_reached ();
     179  	    }
     180  	}
     181      }
     182  
     183    return blob->size;
     184  }
     185  
     186  void
     187  gi_constant_info_class_init (gpointer g_class,
     188                               gpointer class_data)
     189  {
     190    GIBaseInfoClass *info_class = g_class;
     191  
     192    info_class->info_type = GI_INFO_TYPE_CONSTANT;
     193  }