Import NetBSD libexecinfo 20130822 to contrib

1 files changed, 72 insertions, 0 deletions

diff --git a/contrib/libexecinfo/unwind.c b/contrib/libexecinfo/unwind.c
new file mode 100644
index 0000000..b9b785f
--- /dev/null
+++ b/contrib/libexecinfo/unwind.c
@@ -0,0 +1,72 @@
+/*	$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;
+}