lib/sod-hosted.c (sod_makev): Use two statements rather than tricky expression.

[sod] / lib / sod-hosted.c

/* -*-c-*-
 *
 * Runtime support for SOD requiring hosted implementation
 *
 * (c) 2015 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of the Sensible Object Design, an object system for C.
 *
 * SOD is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * SOD 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 Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with SOD; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>

#include "sod.h"

/*----- Preliminary macros ------------------------------------------------*/

#if __STDC_VERSION__ >= 199901
#  define PRIuSZ "zu"
#  define PRINT_SZ(x) (x)
#else
#  define PRIuSZ "lu"
#  define PRINT_SZ(x) ((unsigned long)(x))
#endif

/*----- Main code ---------------------------------------------------------*/

/* --- @sod__chksz_fail@ --- *
 *
 * Arguments:	@const SodClass *cls@ = class we were trying to instantiate
 *		@size_t sz@ = size allocated
 *
 * Returns:	Doesn't.
 *
 * Use:		Reports instantiation failure caused by a mismatch between
 *		the size allocated (@sz@) and the size required for an
 *		instance of class @cls@.
 */

SOD__NORETURN void sod__chksz_fail(const SodClass *cls, size_t sz)
{
  fprintf(stderr, "INTERNAL ERROR: size mismatch for class `%s': "
	  "%"PRIuSZ" allocated but %"PRIuSZ" required",
	  cls->cls.name, PRINT_SZ(sz), PRINT_SZ(cls->cls.initsz));
  abort();
}

/* --- @sod_make@, @sod_makev@ --- *
 *
 * Arguments:	@const SodClass *cls@ = class object for new instance
 *		@va_list ap, ...@ = initialization keyword arguments
 *
 * Returns:	Pointer to the newly-allocated initialized instance, or null.
 *
 * Use:		Allocates storage for a new instance, initializes it, and
 *		returns a pointer to it.  If allocation fails, a null pointer
 *		is returned instead.
 *
 *		This function will allocate the storage using @malloc@, and
 *		then initialize it as for @sod_init@.
 *
 *		It's usually convenient to use the macro @SOD_MAKE@ rather
 *		than calling @sod_make@ directly.
 *
 *		(This function is not available in freestanding environments
 *		lacking @malloc@ and @free@.)
 */

void *sod_make(const SodClass *cls, ...)
{
  void *p;
  va_list ap;

  va_start(ap, cls);
  p = sod_makev(cls, ap);
  va_end(ap);
  return (p);
}

void *sod_makev(const SodClass *cls, va_list ap)
{
  void *p;

  p = malloc(cls->cls.initsz); if (!p) return (0);
  return (sod_initv(cls, p, ap));
}

/* --- @sod_destroy@ --- *
 *
 * Arguments:	@void *p@ = pointer to an instance to be torn down, or null
 *
 * Returns:	Zero if the object was freed; nonzero if it refused for some
 *		reason.
 *
 * Use:		Invokes the instance's `teardown' method to release any held
 *		resources, and then calls @free@ to release the instance's
 *		storage.  See @sod_teardown@ for details, especially
 *		regarding the return value's meaning.
 *
 *		If @p@ is null, then this function does nothing except
 *		returns zero.
 *
 *		(This function is not available in freestanding environments
 *		lacking @malloc@ and @free@.)
 */

int sod_destroy(void *p)
{
  int rc;

  if (!p) return (0);
  rc = sod_teardown(p);
  if (!rc) free(p);
  return (rc);
}

/*----- That's all, folks -------------------------------------------------*/