diff -r e4d67989cc36 -r 47c74d1534e1 glib/gobject/gvaluecollector.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/glib/gobject/gvaluecollector.h Fri Apr 16 16:46:38 2010 +0300 @@ -0,0 +1,195 @@ +/* GObject - GLib Type, Object, Parameter and Signal Library + * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General + * Public License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place, Suite 330, + * Boston, MA 02111-1307, USA. + * + * gvaluecollector.h: GValue varargs stubs + */ +/** + * SECTION:value_collection + * @Short_description: Converting varargs to generic values + * @See_also:#GValueTable + * @Title: Varargs Value Collection + * + * The macros in this section provide the varargs parsing support needed + * in variadic GObject functions such as g_object_new() or g_object_set(). + * They currently support the collection of integral types, floating point + * types and pointers. + */ +#ifndef __G_VALUE_COLLECTOR_H__ +#define __G_VALUE_COLLECTOR_H__ + +#include + +G_BEGIN_DECLS + +/* we may want to add aggregate types here some day, if requested + * by users. the basic C types are covered already, everything + * smaller than an int is promoted to an integer and floats are + * always promoted to doubles for varargs call constructions. + */ +enum /*< skip >*/ +{ + G_VALUE_COLLECT_INT = 'i', + G_VALUE_COLLECT_LONG = 'l', + G_VALUE_COLLECT_INT64 = 'q', + G_VALUE_COLLECT_DOUBLE = 'd', + G_VALUE_COLLECT_POINTER = 'p' +}; + + +/* vararg union holding actuall values collected + */ +/** + * GTypeCValue: + * + * A union holding one collected value. + */ +union _GTypeCValue +{ + gint v_int; + glong v_long; + gint64 v_int64; + gdouble v_double; + gpointer v_pointer; +}; + +/** + * G_VALUE_COLLECT: + * @value: a #GValue return location. @value is supposed to be initialized + * according to the value type to be collected + * @var_args: the va_list variable; it may be evaluated multiple times + * @flags: flags which are passed on to the collect_value() function of + * the #GTypeValueTable of @value. + * @__error: a #gchar** variable that will be modified to hold a g_new() + * allocated error messages if something fails + * + * Collects a variable argument value from a va_list. We have to + * implement the varargs collection as a macro, because on some systems + * va_list variables cannot be passed by reference. + */ +#define G_VALUE_COLLECT(value, var_args, flags, __error) \ +G_STMT_START { \ + GValue *_value = (value); \ + guint _flags = (flags); \ + GType _value_type = G_VALUE_TYPE (_value); \ + GTypeValueTable *_vtable = g_type_value_table_peek (_value_type); \ + gchar *_collect_format = _vtable->collect_format; \ + GTypeCValue _cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \ + guint _n_values = 0; \ + \ + if (_vtable->value_free) \ + _vtable->value_free (_value); \ + _value->g_type = _value_type; /* value_meminit() from gvalue.c */ \ + memset (_value->data, 0, sizeof (_value->data)); \ + while (*_collect_format) \ + { \ + GTypeCValue *_cvalue = _cvalues + _n_values++; \ + \ + switch (*_collect_format++) \ + { \ + case G_VALUE_COLLECT_INT: \ + _cvalue->v_int = va_arg ((var_args), gint); \ + break; \ + case G_VALUE_COLLECT_LONG: \ + _cvalue->v_long = va_arg ((var_args), glong); \ + break; \ + case G_VALUE_COLLECT_INT64: \ + _cvalue->v_int64 = va_arg ((var_args), gint64); \ + break; \ + case G_VALUE_COLLECT_DOUBLE: \ + _cvalue->v_double = va_arg ((var_args), gdouble); \ + break; \ + case G_VALUE_COLLECT_POINTER: \ + _cvalue->v_pointer = va_arg ((var_args), gpointer); \ + break; \ + default: \ + g_assert_not_reached (); \ + } \ + } \ + *(__error) = _vtable->collect_value (_value, \ + _n_values, \ + _cvalues, \ + _flags); \ +} G_STMT_END + + +/** + * G_VALUE_LCOPY: + * @value: a #GValue return location. @value is supposed to be initialized + * according to the value type to be collected + * @var_args: the va_list variable; it may be evaluated multiple times + * @flags: flags which are passed on to the lcopy_value() function of + * the #GTypeValueTable of @value. + * @__error: a #gchar** variable that will be modified to hold a g_new() + * allocated error messages if something fails + * + * Collects a value's variable argument locations from a va_list. Usage is + * analogous to G_VALUE_COLLECT(). + */ +#define G_VALUE_LCOPY(value, var_args, flags, __error) \ +G_STMT_START { \ + const GValue *_value = (value); \ + guint _flags = (flags); \ + GType _value_type = G_VALUE_TYPE (_value); \ + GTypeValueTable *_vtable = g_type_value_table_peek (_value_type); \ + gchar *_lcopy_format = _vtable->lcopy_format; \ + GTypeCValue _cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \ + guint _n_values = 0; \ + \ + while (*_lcopy_format) \ + { \ + GTypeCValue *_cvalue = _cvalues + _n_values++; \ + \ + switch (*_lcopy_format++) \ + { \ + case G_VALUE_COLLECT_INT: \ + _cvalue->v_int = va_arg ((var_args), gint); \ + break; \ + case G_VALUE_COLLECT_LONG: \ + _cvalue->v_long = va_arg ((var_args), glong); \ + break; \ + case G_VALUE_COLLECT_INT64: \ + _cvalue->v_int64 = va_arg ((var_args), gint64); \ + break; \ + case G_VALUE_COLLECT_DOUBLE: \ + _cvalue->v_double = va_arg ((var_args), gdouble); \ + break; \ + case G_VALUE_COLLECT_POINTER: \ + _cvalue->v_pointer = va_arg ((var_args), gpointer); \ + break; \ + default: \ + g_assert_not_reached (); \ + } \ + } \ + *(__error) = _vtable->lcopy_value (_value, \ + _n_values, \ + _cvalues, \ + _flags); \ +} G_STMT_END + + +/** + * G_VALUE_COLLECT_FORMAT_MAX_LENGTH: + * + * The maximal number of #GTypeCValues which can be collected for a + * single #GValue. + */ +#define G_VALUE_COLLECT_FORMAT_MAX_LENGTH (8) + +G_END_DECLS + +#endif /* __G_VALUE_COLLECTOR_H__ */