1 /* GObject - GLib Type, Object, Parameter and Signal Library 2 * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General 15 * Public License along with this library; if not, write to the 16 * Free Software Foundation, Inc., 59 Temple Place, Suite 330, 17 * Boston, MA 02111-1307, USA. 18 * 19 * gvaluecollector.h: GValue varargs stubs 20 */ 21 /** 22 * SECTION:value_collection 23 * @Short_description: Converting varargs to generic values 24 * @See_also:#GValueTable 25 * @Title: Varargs Value Collection 26 * 27 * The macros in this section provide the varargs parsing support needed 28 * in variadic GObject functions such as g_object_new() or g_object_set(). 29 * They currently support the collection of integral types, floating point 30 * types and pointers. 31 */ 32 #ifndef __G_VALUE_COLLECTOR_H__ 33 #define __G_VALUE_COLLECTOR_H__ 34 35 #include <glib-object.h> 36 37 G_BEGIN_DECLS 38 39 /* we may want to add aggregate types here some day, if requested 40 * by users. the basic C types are covered already, everything 41 * smaller than an int is promoted to an integer and floats are 42 * always promoted to doubles for varargs call constructions. 43 */ 44 enum /*< skip >*/ 45 { 46 G_VALUE_COLLECT_INT = 'i', 47 G_VALUE_COLLECT_LONG = 'l', 48 G_VALUE_COLLECT_INT64 = 'q', 49 G_VALUE_COLLECT_DOUBLE = 'd', 50 G_VALUE_COLLECT_POINTER = 'p' 51 }; 52 53 54 /* vararg union holding actuall values collected 55 */ 56 /** 57 * GTypeCValue: 58 * 59 * A union holding one collected value. 60 */ 61 union _GTypeCValue 62 { 63 gint v_int; 64 glong v_long; 65 gint64 v_int64; 66 gdouble v_double; 67 gpointer v_pointer; 68 }; 69 70 /** 71 * G_VALUE_COLLECT: 72 * @value: a #GValue return location. @value is supposed to be initialized 73 * according to the value type to be collected 74 * @var_args: the va_list variable; it may be evaluated multiple times 75 * @flags: flags which are passed on to the collect_value() function of 76 * the #GTypeValueTable of @value. 77 * @__error: a #gchar** variable that will be modified to hold a g_new() 78 * allocated error messages if something fails 79 * 80 * Collects a variable argument value from a va_list. We have to 81 * implement the varargs collection as a macro, because on some systems 82 * va_list variables cannot be passed by reference. 83 */ 84 #define G_VALUE_COLLECT(value, var_args, flags, __error) \ 85 G_STMT_START { \ 86 GValue *_value = (value); \ 87 guint _flags = (flags); \ 88 GType _value_type = G_VALUE_TYPE (_value); \ 89 GTypeValueTable *_vtable = g_type_value_table_peek (_value_type); \ 90 gchar *_collect_format = _vtable->collect_format; \ 91 GTypeCValue _cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \ 92 guint _n_values = 0; \ 93 \ 94 if (_vtable->value_free) \ 95 _vtable->value_free (_value); \ 96 _value->g_type = _value_type; /* value_meminit() from gvalue.c */ \ 97 memset (_value->data, 0, sizeof (_value->data)); \ 98 while (*_collect_format) \ 99 { \ 100 GTypeCValue *_cvalue = _cvalues + _n_values++; \ 101 \ 102 switch (*_collect_format++) \ 103 { \ 104 case G_VALUE_COLLECT_INT: \ 105 _cvalue->v_int = va_arg ((var_args), gint); \ 106 break; \ 107 case G_VALUE_COLLECT_LONG: \ 108 _cvalue->v_long = va_arg ((var_args), glong); \ 109 break; \ 110 case G_VALUE_COLLECT_INT64: \ 111 _cvalue->v_int64 = va_arg ((var_args), gint64); \ 112 break; \ 113 case G_VALUE_COLLECT_DOUBLE: \ 114 _cvalue->v_double = va_arg ((var_args), gdouble); \ 115 break; \ 116 case G_VALUE_COLLECT_POINTER: \ 117 _cvalue->v_pointer = va_arg ((var_args), gpointer); \ 118 break; \ 119 default: \ 120 g_assert_not_reached (); \ 121 } \ 122 } \ 123 *(__error) = _vtable->collect_value (_value, \ 124 _n_values, \ 125 _cvalues, \ 126 _flags); \ 127 } G_STMT_END 128 129 130 /** 131 * G_VALUE_LCOPY: 132 * @value: a #GValue return location. @value is supposed to be initialized 133 * according to the value type to be collected 134 * @var_args: the va_list variable; it may be evaluated multiple times 135 * @flags: flags which are passed on to the lcopy_value() function of 136 * the #GTypeValueTable of @value. 137 * @__error: a #gchar** variable that will be modified to hold a g_new() 138 * allocated error messages if something fails 139 * 140 * Collects a value's variable argument locations from a va_list. Usage is 141 * analogous to G_VALUE_COLLECT(). 142 */ 143 #define G_VALUE_LCOPY(value, var_args, flags, __error) \ 144 G_STMT_START { \ 145 const GValue *_value = (value); \ 146 guint _flags = (flags); \ 147 GType _value_type = G_VALUE_TYPE (_value); \ 148 GTypeValueTable *_vtable = g_type_value_table_peek (_value_type); \ 149 gchar *_lcopy_format = _vtable->lcopy_format; \ 150 GTypeCValue _cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \ 151 guint _n_values = 0; \ 152 \ 153 while (*_lcopy_format) \ 154 { \ 155 GTypeCValue *_cvalue = _cvalues + _n_values++; \ 156 \ 157 switch (*_lcopy_format++) \ 158 { \ 159 case G_VALUE_COLLECT_INT: \ 160 _cvalue->v_int = va_arg ((var_args), gint); \ 161 break; \ 162 case G_VALUE_COLLECT_LONG: \ 163 _cvalue->v_long = va_arg ((var_args), glong); \ 164 break; \ 165 case G_VALUE_COLLECT_INT64: \ 166 _cvalue->v_int64 = va_arg ((var_args), gint64); \ 167 break; \ 168 case G_VALUE_COLLECT_DOUBLE: \ 169 _cvalue->v_double = va_arg ((var_args), gdouble); \ 170 break; \ 171 case G_VALUE_COLLECT_POINTER: \ 172 _cvalue->v_pointer = va_arg ((var_args), gpointer); \ 173 break; \ 174 default: \ 175 g_assert_not_reached (); \ 176 } \ 177 } \ 178 *(__error) = _vtable->lcopy_value (_value, \ 179 _n_values, \ 180 _cvalues, \ 181 _flags); \ 182 } G_STMT_END 183 184 185 /** 186 * G_VALUE_COLLECT_FORMAT_MAX_LENGTH: 187 * 188 * The maximal number of #GTypeCValue<!-- -->s which can be collected for a 189 * single #GValue. 190 */ 191 #define G_VALUE_COLLECT_FORMAT_MAX_LENGTH (8) 192 193 G_END_DECLS 194 195 #endif /* __G_VALUE_COLLECTOR_H__ */ 196
