1From a71fda827da45c357d92d07ea491c208c1e044fe Mon Sep 17 00:00:00 2001
2From: Maksim Kita <maksim-kita@yandex-team.ru>
3Date: Sun, 23 May 2021 10:27:29 +0000
4Subject: [PATCH] libunwind: Added unw_backtrace method
5
6Source: https://github.com/ClickHouse-Extras/libunwind/commit/52f0f7861926cbfaef7e6c97d8a6d7ba2a1f6747#diff-a82fc885e2e4facf4b92d26171c13aa4aa5db296f77e1158ba2f8664e3bd1f5c
7Upstream-Status: Pending
8Signed-off-by: Khem Raj <raj.khem@gmail.com>
9---
10 libunwind/include/libunwind.h |  1 +
11 libunwind/src/libunwind.cpp   | 18 ++++++++++++++++++
12 2 files changed, 19 insertions(+)
13
14diff --git a/libunwind/include/libunwind.h b/libunwind/include/libunwind.h
15index 9a74faa48d6f..f7480c9cf27a 100644
16--- a/libunwind/include/libunwind.h
17+++ b/libunwind/include/libunwind.h
18@@ -127,6 +127,7 @@ extern int unw_is_fpreg(unw_cursor_t *, unw_regnum_t) LIBUNWIND_AVAIL;
19 extern int unw_is_signal_frame(unw_cursor_t *) LIBUNWIND_AVAIL;
20 extern int unw_get_proc_name(unw_cursor_t *, char *, size_t, unw_word_t *) LIBUNWIND_AVAIL;
21 //extern int       unw_get_save_loc(unw_cursor_t*, int, unw_save_loc_t*);
22+extern int unw_backtrace(void **, int) LIBUNWIND_AVAIL;
23
24 extern unw_addr_space_t unw_local_addr_space;
25
26diff --git a/libunwind/src/libunwind.cpp b/libunwind/src/libunwind.cpp
27index 03f8b75b5bba..730e2393a8f8 100644
28--- a/libunwind/src/libunwind.cpp
29+++ b/libunwind/src/libunwind.cpp
30@@ -326,7 +326,25 @@ void __unw_remove_dynamic_eh_frame_section(unw_word_t eh_frame_start) {
31 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
32 #endif // !defined(__USING_SJLJ_EXCEPTIONS__)
33
34+int unw_backtrace(void **buffer, int size) {
35+  unw_context_t context;
36+  unw_cursor_t cursor;
37+  if (unw_getcontext(&context) || unw_init_local(&cursor, &context)) {
38+    return 0;
39+  }
40+
41+  unw_word_t ip;
42+  int current = 0;
43+  while (unw_step(&cursor) > 0) {
44+    if (current >= size || unw_get_reg(&cursor, UNW_REG_IP, &ip)) {
45+      break;
46+    }
47
48+    buffer[current++] = reinterpret_cast<void *>(static_cast<uintptr_t>(ip));
49+  }
50+
51+  return current;
52+}
53
54 // Add logging hooks in Debug builds only
55 #ifndef NDEBUG
56