Import NetBSD libexecinfo 20130822 to contrib

1 files changed, 229 insertions, 0 deletions

diff --git a/contrib/libexecinfo/backtrace.c b/contrib/libexecinfo/backtrace.c
new file mode 100644
index 0000000..02ad148
--- /dev/null
+++ b/contrib/libexecinfo/backtrace.c
@@ -0,0 +1,229 @@
+/*	$NetBSD: backtrace.c,v 1.2 2012/07/09 03:11:59 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>
+__RCSID("$NetBSD: backtrace.c,v 1.2 2012/07/09 03:11:59 christos Exp $");
+
+#include <sys/param.h>
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <dlfcn.h>
+#include <elf.h>
+
+#include "execinfo.h"
+#include "symtab.h"
+
+#ifdef __linux__
+#define SELF	"/proc/self/exe"
+#else
+#define SELF	"/proc/curproc/file"
+#endif
+
+static int __printflike(4, 5)
+rasprintf(char **buf, size_t *bufsiz, size_t offs, const char *fmt, ...)
+{
+	for (;;) {
+		size_t nbufsiz;
+		char *nbuf;
+
+		if (*buf && offs < *bufsiz) {
+			va_list ap;
+			int len;
+
+			va_start(ap, fmt);
+			len = vsnprintf(*buf + offs, *bufsiz - offs, fmt, ap);
+			va_end(ap);
+
+			if (len < 0 || (size_t)len < *bufsiz - offs)
+				return len;
+			nbufsiz = MAX(*bufsiz + 512, (size_t)len + 1);
+		} else
+			nbufsiz = MAX(offs, *bufsiz) + 512;
+			
+		nbuf = realloc(*buf, nbufsiz);
+		if (nbuf == NULL)
+			return -1;
+		*buf = nbuf;
+		*bufsiz = nbufsiz;
+	}
+}
+
+/*
+ * format specifiers:
+ *	%a	= address
+ *	%n	= symbol_name
+ *	%d	= symbol_address - address
+ *	%D	= if symbol_address == address "" else +%d
+ *	%f	= filename
+ */
+static ssize_t
+format_string(char **buf, size_t *bufsiz, size_t offs, const char *fmt,
+    Dl_info *dli, const void *addr)
+{
+	ptrdiff_t diff = (const char *)addr - (const char *)dli->dli_saddr;
+	size_t o = offs;
+	int len;
+
+	for (; *fmt; fmt++) {
+		if (*fmt != '%')
+			goto printone;
+		switch (*++fmt) {
+		case 'a':
+			len = rasprintf(buf, bufsiz, o, "%p", addr);
+			break;
+		case 'n':
+			len = rasprintf(buf, bufsiz, o, "%s", dli->dli_sname);
+			break;
+		case 'D':
+			if (diff)
+				len = rasprintf(buf, bufsiz, o, "+0x%tx", diff);
+			else
+				len = 0;
+			break;
+		case 'd':
+			len = rasprintf(buf, bufsiz, o, "0x%tx", diff);
+			break;
+		case 'f':
+			len = rasprintf(buf, bufsiz, o, "%s", dli->dli_fname);
+			break;
+		default:
+		printone:
+			len = rasprintf(buf, bufsiz, o, "%c", *fmt);
+			break;
+		}
+		if (len == -1)
+			return -1;
+		o += len;
+	}
+	return o - offs;
+}
+
+static ssize_t
+format_address(symtab_t *st, char **buf, size_t *bufsiz, size_t offs,
+    const char *fmt, const void *addr)
+{
+	Dl_info dli;
+
+	memset(&dli, 0, sizeof(dli));
+	(void)dladdr(addr, &dli);
+	if (st)
+		symtab_find(st, addr, &dli);
+
+	if (dli.dli_sname == NULL)
+		dli.dli_sname = "???";
+	if (dli.dli_fname == NULL)
+		dli.dli_fname = "???";
+	if (dli.dli_saddr == NULL)
+		dli.dli_saddr = (void *)(intptr_t)addr;
+
+	return format_string(buf, bufsiz, offs, fmt, &dli, addr);
+}
+
+char **
+backtrace_symbols_fmt(void *const *trace, size_t len, const char *fmt)
+{
+
+	static const size_t slen = sizeof(char *) + 64;	/* estimate */
+	char *ptr;
+	symtab_t *st;
+	int fd;
+
+	if ((fd = open(SELF, O_RDONLY)) != -1)
+		st = symtab_create(fd, -1, STT_FUNC);
+	else
+		st = NULL;
+
+	if ((ptr = calloc(len, slen)) == NULL)
+		goto out;
+
+	size_t psize = len * slen;
+	size_t offs = len * sizeof(char *);
+
+	/* We store only offsets in the first pass because of realloc */
+	for (size_t i = 0; i < len; i++) {
+		ssize_t x;
+		((char **)(void *)ptr)[i] = (void *)offs;
+		x = format_address(st, &ptr, &psize, offs, fmt, trace[i]);
+		if (x == -1) {
+			free(ptr);
+			ptr = NULL;
+			goto out;
+		}
+		offs += x;
+		ptr[offs++] = '\0';
+		assert(offs < psize);
+	}
+
+	/* Change offsets to pointers */
+	for (size_t j = 0; j < len; j++)
+		((char **)(void *)ptr)[j] += (intptr_t)ptr;
+
+out:
+	symtab_destroy(st);
+	if (fd != -1)
+		(void)close(fd);
+
+	return (void *)ptr;
+}
+
+int
+backtrace_symbols_fd_fmt(void *const *trace, size_t len, int fd,
+    const char *fmt)
+{
+	char **s = backtrace_symbols_fmt(trace, len, fmt);
+	if (s == NULL)
+		return -1;
+	for (size_t i = 0; i < len; i++)
+		if (dprintf(fd, "%s\n", s[i]) < 0)
+			break;
+	free(s);
+	return 0;
+}
+
+static const char fmt[] = "%a <%n%D> at %f";
+
+char **
+backtrace_symbols(void *const *trace, size_t len)
+{
+	return backtrace_symbols_fmt(trace, len, fmt);
+}
+
+int
+backtrace_symbols_fd(void *const *trace, size_t len, int fd)
+{
+	return backtrace_symbols_fd_fmt(trace, len, fd, fmt);
+}