lib/libexecinfo/builtin.c

   1 /*      $NetBSD: builtin.c,v 1.1 2012/05/26 22:02:29 christos Exp $     */
   2
   3 /*-
   4  * Copyright (c) 2012 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Christos Zoulas.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 #include <sys/cdefs.h>
  32 #include <sys/param.h>
  33 #include <sys/types.h>
  34
  35 #include "execinfo.h"
  36
  37 #ifdef __MACHINE_STACK_GROWS_UP
  38 #define BELOW >
  39 #else
  40 #define BELOW <
  41 #endif
  42
  43 #ifdef __lint__
  44 #define __builtin_frame_address(a)      ((void *)a)
  45 #endif
  46
  47 struct frameinfo {
  48         struct frameinfo *next;
  49         void *return_address;
  50 };
  51
  52 size_t
  53 backtrace(void **trace, size_t len)
  54 {
  55         const struct frameinfo *frame = __builtin_frame_address(0);
  56         void *stack = &stack;
  57
  58         for (size_t i = 0; i < len; i++) {
  59                 if ((const void *)frame BELOW stack)
  60                         return i;
  61                 trace[i] = frame->return_address;
  62                 frame = frame->next;
  63         }
  64
  65         return len;
  66 }