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freebsd/contrib/libexecinfo/unwind.c

73 lines
2.2 KiB
C

/* $NetBSD: unwind.c,v 1.1 2012/05/26 22:02:29 christos Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <stdio.h>
#include "unwind.h"
#include "execinfo.h"
struct tracer_context {
void **arr;
size_t len;
size_t n;
};
static _Unwind_Reason_Code
tracer(struct _Unwind_Context *ctx, void *arg)
{
struct tracer_context *t = arg;
if (t->n == (size_t)~0) {
/* Skip backtrace frame */
t->n = 0;
return 0;
}
if (t->n < t->len)
t->arr[t->n++] = _Unwind_GetIP(ctx);
return 0;
}
size_t
backtrace(void **arr, size_t len)
{
struct tracer_context ctx;
ctx.arr = arr;
ctx.len = len;
ctx.n = (size_t)~0;
_Unwind_Backtrace(tracer, &ctx);
if (ctx.n != (size_t)~0 && ctx.n > 0)
ctx.arr[--ctx.n] = NULL; /* Skip frame below __start */
return ctx.n;
}