libunwind: Implement unw_backtrace

Signed-off-by: Khem Raj <raj.khem@gmail.com>
(cherry picked from commit d45403baedd7ae7755a02cfe0205000b760167bd)

2 files changed, 56 insertions, 0 deletions

diff --git a/recipes-devtools/clang/clang/0033-libunwind-Added-unw_backtrace-method.patch b/recipes-devtools/clang/clang/0033-libunwind-Added-unw_backtrace-method.patch
new file mode 100644
index 0000000..53f816d
--- /dev/null
+++ b/recipes-devtools/clang/clang/0033-libunwind-Added-unw_backtrace-method.patch
@@ -0,0 +1,55 @@
+From 79195637cf6cde28baa23e41e7b417e98b036913 Mon Sep 17 00:00:00 2001
+From: Maksim Kita <maksim-kita@yandex-team.ru>
+Date: Sun, 23 May 2021 10:27:29 +0000
+Subject: [PATCH] libunwind: Added unw_backtrace method
+
+Source: https://github.com/ClickHouse-Extras/libunwind/commit/52f0f7861926cbfaef7e6c97d8a6d7ba2a1f6747#diff-a82fc885e2e4facf4b92d26171c13aa4aa5db296f77e1158ba2f8664e3bd1f5c
+Upstream-Status: Pending
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ libunwind/include/libunwind.h |  1 +
+ libunwind/src/libunwind.cpp   | 18 ++++++++++++++++++
+ 2 files changed, 19 insertions(+)
+
+diff --git a/libunwind/include/libunwind.h b/libunwind/include/libunwind.h
+index 0feecd7bd6fc..670cfa3ed71d 100644
+--- a/libunwind/include/libunwind.h
++++ b/libunwind/include/libunwind.h
+@@ -127,6 +127,7 @@ extern int unw_is_fpreg(unw_cursor_t *, unw_regnum_t) LIBUNWIND_AVAIL;
+ extern int unw_is_signal_frame(unw_cursor_t *) LIBUNWIND_AVAIL;
+ extern int unw_get_proc_name(unw_cursor_t *, char *, size_t, unw_word_t *) LIBUNWIND_AVAIL;
+ //extern int       unw_get_save_loc(unw_cursor_t*, int, unw_save_loc_t*);
++extern int unw_backtrace(void **, int) LIBUNWIND_AVAIL;
+ 
+ extern unw_addr_space_t unw_local_addr_space;
+ 
+diff --git a/libunwind/src/libunwind.cpp b/libunwind/src/libunwind.cpp
+index 9b3b92bdff09..986ef62f9231 100644
+--- a/libunwind/src/libunwind.cpp
++++ b/libunwind/src/libunwind.cpp
+@@ -289,7 +289,25 @@ void __unw_remove_dynamic_fde(unw_word_t fde) {
+ #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
+ #endif // !defined(__USING_SJLJ_EXCEPTIONS__)
+ 
++int unw_backtrace(void **buffer, int size) {
++  unw_context_t context;
++  unw_cursor_t cursor;
++  if (unw_getcontext(&context) || unw_init_local(&cursor, &context)) {
++    return 0;
++  }
++
++  unw_word_t ip;
++  int current = 0;
++  while (unw_step(&cursor) > 0) {
++    if (current >= size || unw_get_reg(&cursor, UNW_REG_IP, &ip)) {
++      break;
++    }
+ 
++    buffer[current++] = reinterpret_cast<void *>(static_cast<uintptr_t>(ip));
++  }
++
++  return current;
++}
+ 
+ // Add logging hooks in Debug builds only
+ #ifndef NDEBUG
diff --git a/recipes-devtools/clang/common.inc b/recipes-devtools/clang/common.inc
index d68d6f5..7f1a5f3 100644
--- a/recipes-devtools/clang/common.inc
+++ b/recipes-devtools/clang/common.inc
@@ -42,6 +42,7 @@ SRC_URI = "\
     file://0030-clang-Fix-x86-triple-for-non-debian-multiarch-linux-.patch \
     file://0031-compiler-rt-Link-scudo-with-SANITIZER_CXX_ABI_LIBRAR.patch \
     file://0032-compiler-rt-Link-scudo-standalone-with-libatomic-on-.patch \
+    file://0033-libunwind-Added-unw_backtrace-method.patch \
     file://0034-CMake-Installable-find-modules-for-terminfo-and-libf.patch \
     file://0035-llvm-Do-not-use-standard-search-paths-in-find_librar.patch \
 "