1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 
  27 #ifndef _ALLOCA_H
  28 #define _ALLOCA_H
  29 
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31 
  32 #include <sys/types.h>
  33 
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37 
  38 /*
  39  * Many compilation systems depend upon the use of special functions
  40  * built into the the compilation system to handle variable argument
  41  * lists and stack allocations.  The method to obtain this in SunOS
  42  * is to define the feature test macro "__BUILTIN_VA_ARG_INCR" which
  43  * enables the following special built-in functions:
  44  *      __builtin_alloca
  45  *      __builtin_va_alist
  46  *      __builtin_va_arg_incr
  47  * It is intended that the compilation system define this feature test
  48  * macro, not the user of the system.
  49  *
  50  * The tests on the processor type are to provide a transitional period
  51  * for existing compilation systems, and may be removed in a future
  52  * release.
  53  */
  54 
  55 #if defined(__BUILTIN_VA_ARG_INCR) || \
  56         defined(__sparc) || defined(__i386) || defined(__amd64)
  57 #define alloca(x)       __builtin_alloca(x)
  58 
  59 #ifdef  __STDC__
  60 extern void *__builtin_alloca(size_t);
  61 #else
  62 extern void *__builtin_alloca();
  63 #endif
  64 
  65 #else
  66 
  67 #ifdef  __STDC__
  68 extern void *alloca(size_t);
  69 #else
  70 extern void *alloca();
  71 #endif
  72 
  73 #endif  /* defined(__BUILTIN_VA_ARG_INCR) || defined(__sparc) ... */
  74 
  75 #ifdef __cplusplus
  76 }
  77 #endif
  78 
  79 #endif  /* _ALLOCA_H */