/* $Id$
 * Include file with general macros and typedefs used through Captive project
 * Copyright (C) 2002 Jan Kratochvil <project-captive@jankratochvil.net>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; exactly version 2 of June 1991 is required
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#ifndef _CAPTIVE_MACROS_H
#define _CAPTIVE_MACROS_H 1


#include <glib/gmacros.h>
#include <glib/gmem.h>
#include <stdarg.h>
#include <string.h>	/* for memset() */
#include <glib/galloca.h>
#include <glib/gmessages.h>
#include <glib/gutils.h>	/* for g_snprintf(); glib-2.2.x+ it also has in <glib/gprintf.h> */


G_BEGIN_DECLS

/**
 * CAPTIVE_FAKEUSE:
 *
 * Prevent 'might be used uninitialized' warning.
 * Macro will fakes the use of the variable as sometimes GCC can't code flow
 * analyse #C correctly.
 *
 * <informalexample>
 * <programlisting>
 * g_some_type some_variable CAPTIVE_FAKEUSE;
 * </programlisting>
 * </informalexample>
 */
#define CAPTIVE_FAKEUSE =0


/**
 * captive_newn:
 * @objp: Variable with the pointer to the objects wished to be allocated.
 * Original value is discarded.
 * @n: Numbers of objects to be allocated. Value %0 is permitted (%NULL assignment effect).
 *
 * Macro to allocate @n objects of type *@objp and to assign the resulting pointer to @objp.
 * Allocated memory may contain garbage.
 *
 * @Returns: Initialized @objp value as the memory of size #sizeof(typeof(*objp))*n.
 * Value %NULL is returned iff @n==%0;
 */
#define captive_newn(objp,n) ((objp)=g_new(typeof(*(objp)),(n)))


/**
 * captive_new0n:
 * @objp: Variable with the pointer to the objects wished to be allocated and precleared.
 * Original value is discarded.
 * @n: Numbers of objects to be allocated. Value %0 is permitted (%NULL assignment effect).
 *
 * Macro to allocate @n objects of type *@objp and to assign the resulting pointer to @objp.
 * Allocated memory is precleared.
 * 
 * @Returns: Initialized @objp value as the cleared memory of size #sizeof(typeof(*objp))*n.
 * Value %NULL is returned iff @n==%0;
 */
#define captive_new0n(objp,n) ((objp)=g_new0(typeof(*(objp)),(n)))


/**
 * captive_renewn:
 * @objp: Variable with the pointer to the objects wished to be reallocated. 
 * Value %NULL is permitted (g_malloc() effect).
 * @n: Numbers of objects to be allocated. Value %0 is permitted (g_free() effect).
 *
 * Macro to reallocate the original memory stored in @objp
 * to the size @n objects of type *@objp and to assign the resulting pointer to @objp.
 * New allocated space may contain garbage. Both @objp and @n can be nonexclusively
 * passed as zero.
 * 
 * @Returns: Initialized @objp value as the memory of size #sizeof(typeof(*objp))*n.
 * Value %NULL is returned iff @n==%0;
 */
#define captive_renewn(objp,n) ({ \
		typeof(&(objp)) _captive_renewn_objpp=&(objp); \
		*_captive_renewn_objpp=g_renew(typeof(*(objp)),*_captive_renewn_objpp,(n)); \
		(*_captive_renewn_objpp); \
		})


/**
 * captive_new:
 * @objp: Variable with the pointer to the object wished to be allocated.
 * Original value is discarded.
 *
 * Macro to allocate one object of type *@objp and to assign the resulting pointer to @objp.
 * Allocated memory may contain garbage. Equivalent to captive_newn(objp,1) call.
 *
 * @Returns: Initialized @objp value as the memory of size #sizeof(typeof(*objp)).
 * Value %NULL is never returned.
 */
#define captive_new(objp) (captive_newn((objp),1))


/**
 * captive_new0:
 * @objp: Variable with the pointer to the object wished to be allocated and precleared.
 * Original value is discarded.
 *
 * Macro to allocate one object of type *@objp and to assign the resulting pointer to @objp.
 * Allocated memory is precleared. Equivalent to captive_new0n(objp,1) call.
 * 
 * @Returns: Initialized @objp value as the cleared memory of size #sizeof(typeof(*objp)).
 * Value %NULL is never returned.
 */
#define captive_new0(objp) (captive_new0n((objp),1))


/**
 * captive_newn_alloca:
 * @objp: Variable with the pointer to the objects wished to be allocated.
 * Original value is discarded.
 * @n: Numbers of objects to be allocated. Value %0 is permitted (%NULL assignment effect).
 *
 * Macro to allocate @n objects of type *@objp and to assign the resulting pointer to @objp.
 * Allocated memory may contain garbage.
 * 
 * Memory is allocated on the stack frame by g_alloca() and it will be automatically deallocated
 * during exit of current function (or current block if variable sized variables present there).
 * You cannot deallocate or reallocate such memory in any other way.
 *
 * @Returns: Initialized @objp value as the memory of size #sizeof(typeof(*objp))*n.
 * Value %NULL is returned iff @n==%0;
 */
#define captive_newn_alloca(objp,n) ({ \
		gsize _captive_newn_alloca_n=(n); \
		/* Fix 'g_alloca(0)!=NULL': */ \
		((objp)=(!_captive_newn_alloca_n ? NULL : g_alloca(sizeof(*(objp))*_captive_newn_alloca_n))); \
		})


/**
 * captive_new0n_alloca:
 * @objp: Variable with the pointer to the objects wished to be allocated and precleared.
 * Original value is discarded.
 * @n: Numbers of objects to be allocated. Value %0 is permitted (%NULL assignment effect).
 *
 * Macro to allocate @n objects of type *@objp and to assign the resulting pointer to @objp.
 * Allocated memory is precleared.
 * 
 * Memory is allocated on the stack frame by g_alloca() and it will be automatically deallocated
 * during exit of current function (or current block if variable sized variables present there).
 * You cannot deallocate or reallocate such memory in any other way.
 * 
 * @Returns: Initialized @objp value as the cleared memory of size #sizeof(typeof(*objp))*n.
 * Value %NULL is returned iff @n==%0;
 */
#define captive_new0n_alloca(objp,n) ({ \
		typeof(&(objp)) _captive_new0n_alloca_objpp=&(objp); \
		captive_newn_alloca(*_captive_new0n_alloca_objpp,(n)); \
		CAPTIVE_MEMZERO(*_captive_new0n_alloca_objpp); \
		(*_captive_new0n_alloca_objpp); \
		})


/**
 * captive_new_alloca:
 * @objp: Variable with the pointer to the object wished to be allocated.
 * Original value is discarded.
 *
 * Macro to allocate one object of type *@objp and to assign the resulting pointer to @objp.
 * Allocated memory may contain garbage. Equivalent to captive_newn_alloca(objp,1) call.
 * 
 * Memory is allocated on the stack frame by g_alloca() and it will be automatically deallocated
 * during exit of current function (or current block if variable sized variables present there).
 * You cannot deallocate or reallocate such memory in any other way.
 *
 * @Returns: Initialized @objp value as the memory of size #sizeof(typeof(*objp)).
 * Value %NULL is never returned.
 */
#define captive_new_alloca(objp) (captive_newn_alloca((objp),1))


/**
 * captive_new0_alloca:
 * @objp: Variable with the pointer to the object wished to be allocated and precleared.
 * Original value is discarded.
 *
 * Macro to allocate one object of type *@objp and to assign the resulting pointer to @objp.
 * Allocated memory is precleared. Equivalent to captive_new0n_alloca(objp,1) call.
 * 
 * @Returns: Initialized @objp value as the cleared memory of size #sizeof(typeof(*objp)).
 */
#define captive_new0_alloca(objp) (captive_new0n_alloca((objp),1))


/**
 * captive_memdup:
 * @destp: Variable with the pointer to the target object wished to be allocated.
 * Original value is discarded.
 * @srcp: Pointer to the source object to be copied to @destp.
 *
 * Macro to similiar to g_memdup() but the object size is detected automatically.
 * Size of @destp object and @srcp object must be the same.
 * 
 * You must free the allocated memory of @destp by g_free().
 * 
 * @Returns: Initialized @destp value as the copied memory of size #sizeof(typeof(*srcp)).
 */
#define captive_memdup(destp,srcp) ({ \
		typeof(&(destp)) _captive_captive_memdup_destpp=&(destp); \
		g_assert(sizeof(*(destp))==sizeof(*(srcp))); \
		captive_new(*_captive_captive_memdup_destpp); \
		memcpy(*_captive_captive_memdup_destpp,(srcp),sizeof(*(srcp))); \
		(*_captive_captive_memdup_destpp); \
		})


/**
 * captive_va_arg:
 * @objp: Variable to be filled from the next argument of @ap.
 * @ap: Initialized #va_list type.
 *
 * Automatically determines the size of @objp.
 * Equivalent to objp=va_arg(ap,typeof(objp)) call.
 *
 * @Returns: Initialized @objp value.
 */
#define captive_va_arg(objp,ap) ((objp)=va_arg((ap),typeof(objp)))


/**
 * CAPTIVE_MEMZERO:
 * @objp: Pointer to the variable to be cleared.
 *
 * Clears the sizeof(*@objp) bytes of the given pointer with memset().
 * Pass _pointer_ to the object to be cleared.
 */
#define CAPTIVE_MEMZERO(objp) (memset((objp),0,sizeof(*(objp))))


/**
 * captive_printf_alloca:
 * @format: Format string. See the sprintf() documentation.
 * @args...: Arguments for @format. See the sprintf() documentation.
 *
 * Format the given format string @format as in sprintf().
 * Output buffer is allocated automatically and it does not need to be deallocated
 * manually as it is managed by g_alloca().
 *
 * @Returns: Formatted output string located in g_alloca() memory.
 */
#define captive_printf_alloca(format,args...) ({ \
		gsize _captive_printf_alloca_size=captive_nv_printf_string_upper_bound((format) , ## args); \
		gchar *_captive_printf_alloca_r=g_alloca(_captive_printf_alloca_size); \
		g_snprintf(_captive_printf_alloca_r,_captive_printf_alloca_size,(format) , ## args); \
		(const gchar *)_captive_printf_alloca_r; \
		})
static inline gsize captive_nv_printf_string_upper_bound(const gchar *format,...) G_GNUC_PRINTF(1,0) G_GNUC_UNUSED;
static inline gsize captive_nv_printf_string_upper_bound(const gchar *format,...)
{
va_list ap;
gsize r;

	va_start(ap,format);
	r=g_printf_string_upper_bound(format,ap);
	va_end(ap);
	return r;
}


/**
 * captive_strdup_alloca:
 * @string: #const #gchar * string to duplicate.
 *
 * Macro to do g_strdup() equivalent in g_alloca() style.
 * 
 * Memory is allocated on the stack frame by g_alloca() and it will be automatically deallocated
 * during exit of current function (or current block if variable sized variables present there).
 * You cannot deallocate or reallocate such memory in any other way.
 *
 * @Returns: Duplicated @string. You may modify its items if the length is not changed.
 */
#define captive_strdup_alloca(string) ({ \
		const gchar *_captive_strdup_alloca_string=(string); \
		const gchar *_captive_strdup_alloca_r=g_alloca(strlen(_captive_strdup_alloca_string)+1); \
		strcpy((gchar *)_captive_strdup_alloca_r,_captive_strdup_alloca_string); \
		(const gchar *)(_captive_strdup_alloca_r); \
		})


/**
 * CAPTIVE_ROUND_DOWN:
 * @pointer: Arbitrary pointer type.
 * @fragment: Amount of 'sizeof(char)' to align @pointer down to.
 * This size will be typically a power of 2.
 * Value less or equal to %0 is forbidden.
 *
 * General pointer down-rounding macro. Already aligned pointer is left as is.
 *
 * glib NOTE: YOU MAY NOT STORE POINTERS IN INTEGERS.
 *
 * @Returns: Down-rounded @pointer to the integer multiple of @fragment.
 * Resulting pointer has the same type as @pointer.
 */
#define CAPTIVE_ROUND_DOWN(pointer,fragment) \
		((typeof(pointer))(((guint32)(pointer))-CAPTIVE_ROUND_DOWN_EXCEEDING((pointer),(fragment))))
#define CAPTIVE_ROUND_DOWN64(pointer,fragment) \
		((typeof(pointer))(((guint64)(pointer))-CAPTIVE_ROUND_DOWN_EXCEEDING64((pointer),(fragment))))


/**
 * CAPTIVE_ROUND_DOWN_EXCEEDING:
 * @pointer: Arbitrary pointer type.
 * @fragment: Amount of 'sizeof(char)' to detect down-alignment amount of @pointer for.
 * This size will be typically a power of 2.
 * Value less or equal to %0 is forbidden.
 *
 * Detects current non-aligned amount of data exceeding over integer multiple of @fragment.
 * It will return value %0 for an aligned pointer.
 *
 * glib NOTE: YOU MAY NOT STORE POINTERS IN INTEGERS.
 *
 * @Returns: #gsize typed number of bytes exceeding over integer multiple of @fragment.
 */
#define CAPTIVE_ROUND_DOWN_EXCEEDING(pointer,fragment) \
		((gsize)(((guint32)(pointer))%(fragment)))
#define CAPTIVE_ROUND_DOWN_EXCEEDING64(pointer,fragment) \
		((gsize)(((guint64)(pointer))%(fragment)))


/**
 * CAPTIVE_ROUND_UP:
 * @pointer: Arbitrary pointer type.
 * @fragment: Amount of 'sizeof(char)' to align @pointer up to.
 * This size will be typically a power of 2.
 * Value less or equal to %0 is forbidden.
 *
 * General pointer up-rounding macro. Already aligned pointer is left as is.
 *
 * glib NOTE: YOU MAY NOT STORE POINTERS IN INTEGERS.
 *
 * @Returns: Up-rounded @pointer to the integer multiple of @fragment.
 * Resulting pointer has the same type as @pointer.
 */
#define CAPTIVE_ROUND_UP(pointer,fragment) \
		/* new retyping as 'pointer' gets passed as 'char *' to CAPTIVE_ROUND_DOWN(). */ \
		((typeof(pointer))(CAPTIVE_ROUND_DOWN(((guint32)(pointer))+(fragment)-1,(fragment))))
#define CAPTIVE_ROUND_UP64(pointer,fragment) \
		/* new retyping as 'pointer' gets passed as 'char *' to CAPTIVE_ROUND_DOWN(). */ \
		((typeof(pointer))(CAPTIVE_ROUND_DOWN64(((guint64)(pointer))+(fragment)-1,(fragment))))

G_END_DECLS


#endif /* _CAPTIVE_MACROS_H */