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/* 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 2.1 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, see <http://www.gnu.org/licenses/>.
*
* gvaluecollector.h: GValue varargs stubs
*/
/**
* SECTION:value_collection
* @Short_description: Converting varargs to generic values
* @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 <glib-object.h>
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 actual values collected
*/
/**
* GTypeCValue:
* @v_int: the field for holding integer values
* @v_long: the field for holding long integer values
* @v_int64: the field for holding 64 bit integer values
* @v_double: the field for holding floating point values
* @v_pointer: the field for holding pointers
*
* 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_INIT:
* @value: a #GValue return location. @value must contain only 0 bytes.
* @_value_type: the #GType to use for @value.
* @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.
*
* Since: 2.24
*/
#define G_VALUE_COLLECT_INIT(value, _value_type, var_args, flags, __error) \
G_STMT_START { \
GValue *g_vci_val = (value); \
guint g_vci_flags = (flags); \
GTypeValueTable *g_vci_vtab = g_type_value_table_peek (_value_type); \
const gchar *g_vci_collect_format = g_vci_vtab->collect_format; \
GTypeCValue g_vci_cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \
guint g_vci_n_values = 0; \
\
g_vci_val->g_type = _value_type; /* value_meminit() from gvalue.c */ \
while (*g_vci_collect_format) \
{ \
GTypeCValue *g_vci_cvalue = g_vci_cvalues + g_vci_n_values++; \
\
switch (*g_vci_collect_format++) \
{ \
case G_VALUE_COLLECT_INT: \
g_vci_cvalue->v_int = va_arg ((var_args), gint); \
break; \
case G_VALUE_COLLECT_LONG: \
g_vci_cvalue->v_long = va_arg ((var_args), glong); \
break; \
case G_VALUE_COLLECT_INT64: \
g_vci_cvalue->v_int64 = va_arg ((var_args), gint64); \
break; \
case G_VALUE_COLLECT_DOUBLE: \
g_vci_cvalue->v_double = va_arg ((var_args), gdouble); \
break; \
case G_VALUE_COLLECT_POINTER: \
g_vci_cvalue->v_pointer = va_arg ((var_args), gpointer); \
break; \
default: \
g_assert_not_reached (); \
} \
} \
*(__error) = g_vci_vtab->collect_value (g_vci_val, \
g_vci_n_values, \
g_vci_cvalues, \
g_vci_flags); \
} G_STMT_END
/**
* 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.
*
* Note: If you are creating the @value argument just before calling this macro,
* you should use the #G_VALUE_COLLECT_INIT variant and pass the unitialized
* #GValue. That variant is faster than #G_VALUE_COLLECT.
*/
#define G_VALUE_COLLECT(value, var_args, flags, __error) G_STMT_START { \
GValue *g_vc_value = (value); \
GType g_vc_value_type = G_VALUE_TYPE (g_vc_value); \
GTypeValueTable *g_vc_vtable = g_type_value_table_peek (g_vc_value_type); \
\
if (g_vc_vtable->value_free) \
g_vc_vtable->value_free (g_vc_value); \
memset (g_vc_value->data, 0, sizeof (g_vc_value->data)); \
\
G_VALUE_COLLECT_INIT(value, g_vc_value_type, var_args, flags, __error); \
} G_STMT_END
/**
* G_VALUE_COLLECT_SKIP:
* @_value_type: the #GType of the value to skip
* @var_args: the va_list variable; it may be evaluated multiple times
*
* Skip an argument of type @_value_type from @var_args.
*/
#define G_VALUE_COLLECT_SKIP(_value_type, var_args) \
G_STMT_START { \
GTypeValueTable *g_vcs_vtable = g_type_value_table_peek (_value_type); \
const gchar *g_vcs_collect_format = g_vcs_vtable->collect_format; \
\
while (*g_vcs_collect_format) \
{ \
switch (*g_vcs_collect_format++) \
{ \
case G_VALUE_COLLECT_INT: \
va_arg ((var_args), gint); \
break; \
case G_VALUE_COLLECT_LONG: \
va_arg ((var_args), glong); \
break; \
case G_VALUE_COLLECT_INT64: \
va_arg ((var_args), gint64); \
break; \
case G_VALUE_COLLECT_DOUBLE: \
va_arg ((var_args), gdouble); \
break; \
case G_VALUE_COLLECT_POINTER: \
va_arg ((var_args), gpointer); \
break; \
default: \
g_assert_not_reached (); \
} \
} \
} G_STMT_END
/**
* G_VALUE_LCOPY:
* @value: a #GValue to store into the @var_args; this must be initialized
* and set
* @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 message if something fails
*
* Stores a value’s value into one or more argument locations from a va_list.
* This is the inverse of G_VALUE_COLLECT().
*/
#define G_VALUE_LCOPY(value, var_args, flags, __error) \
G_STMT_START { \
const GValue *g_vl_value = (value); \
guint g_vl_flags = (flags); \
GType g_vl_value_type = G_VALUE_TYPE (g_vl_value); \
GTypeValueTable *g_vl_vtable = g_type_value_table_peek (g_vl_value_type); \
const gchar *g_vl_lcopy_format = g_vl_vtable->lcopy_format; \
GTypeCValue g_vl_cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \
guint g_vl_n_values = 0; \
\
while (*g_vl_lcopy_format) \
{ \
GTypeCValue *g_vl_cvalue = g_vl_cvalues + g_vl_n_values++; \
\
switch (*g_vl_lcopy_format++) \
{ \
case G_VALUE_COLLECT_INT: \
g_vl_cvalue->v_int = va_arg ((var_args), gint); \
break; \
case G_VALUE_COLLECT_LONG: \
g_vl_cvalue->v_long = va_arg ((var_args), glong); \
break; \
case G_VALUE_COLLECT_INT64: \
g_vl_cvalue->v_int64 = va_arg ((var_args), gint64); \
break; \
case G_VALUE_COLLECT_DOUBLE: \
g_vl_cvalue->v_double = va_arg ((var_args), gdouble); \
break; \
case G_VALUE_COLLECT_POINTER: \
g_vl_cvalue->v_pointer = va_arg ((var_args), gpointer); \
break; \
default: \
g_assert_not_reached (); \
} \
} \
*(__error) = g_vl_vtable->lcopy_value (g_vl_value, \
g_vl_n_values, \
g_vl_cvalues, \
g_vl_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__ */
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