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[ceph.git] / ceph / src / boost / boost / stacktrace / detail / collect_unwind.ipp

diff --git a/ceph/src/boost/boost/stacktrace/detail/collect_unwind.ipp b/ceph/src/boost/boost/stacktrace/detail/collect_unwind.ipp
index 98d8fcb7f89d87c027c10650e81eb7f25e1a832d..f03aebf5bb109d83baf6e4cc12d55e6ff6b768a1 100644 (file)
--- a/ceph/src/boost/boost/stacktrace/detail/collect_unwind.ipp
+++ b/ceph/src/boost/boost/stacktrace/detail/collect_unwind.ipp
@@ -1,4 +1,4 @@
-// Copyright Antony Polukhin, 2016-2017.
+// Copyright Antony Polukhin, 2016-2019.
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -14,7 +14,19 @@
 
 #include <boost/stacktrace/safe_dump_to.hpp>
 
+// On iOS 32-bit ARM architecture _Unwind_Backtrace function doesn't exist, symbol is undefined.
+// Forcing libc backtrace() function usage.
+#include <boost/predef.h>
+#if defined(BOOST_OS_IOS_AVAILABLE) && defined(BOOST_ARCH_ARM_AVAILABLE) && BOOST_VERSION_NUMBER_MAJOR(BOOST_ARCH_ARM) < 8
+#define BOOST_STACKTRACE_USE_LIBC_BACKTRACE_FUNCTION
+#endif
+
+#if defined(BOOST_STACKTRACE_USE_LIBC_BACKTRACE_FUNCTION)
+#include <execinfo.h>
+#include <algorithm>
+#else
 #include <unwind.h>
+#endif
 #include <cstdio>
 
 #if !defined(_GNU_SOURCE) && !defined(BOOST_STACKTRACE_GNU_SOURCE_NOT_REQUIRED) && !defined(BOOST_WINDOWS)
@@ -23,6 +35,7 @@
 
 namespace boost { namespace stacktrace { namespace detail {
 
+#if !defined(BOOST_STACKTRACE_USE_LIBC_BACKTRACE_FUNCTION)
 struct unwind_state {
     std::size_t frames_to_skip;
     native_frame_ptr_t* current;
@@ -48,16 +61,35 @@ inline _Unwind_Reason_Code unwind_callback(::_Unwind_Context* context, void* arg
     }
     return ::_URC_NO_REASON;
 }
+#endif //!defined(BOOST_STACKTRACE_USE_LIBC_BACKTRACE_FUNCTION)
 
 std::size_t this_thread_frames::collect(native_frame_ptr_t* out_frames, std::size_t max_frames_count, std::size_t skip) BOOST_NOEXCEPT {
     std::size_t frames_count = 0;
     if (!max_frames_count) {
         return frames_count;
     }
-
-    boost::stacktrace::detail::unwind_state state = { skip + 1, out_frames, out_frames + max_frames_count };
+    skip += 1;
+
+#if defined(BOOST_STACKTRACE_USE_LIBC_BACKTRACE_FUNCTION)
+    // According to https://opensource.apple.com/source/Libc/Libc-1272.200.26/gen/backtrace.c.auto.html
+    // it looks like the `::backtrace` is async signal safe.
+    frames_count = static_cast<size_t>(::backtrace(const_cast<void **>(out_frames), static_cast<int>(max_frames_count)));
+
+    // NOTE: There is no way to pass "skip" count to backtrace function so we need to perform left shift operation.
+    // If number of elements in result backtrace is >= max_frames_count then "skip" elements are wasted.
+    if (frames_count && skip) {
+       if (skip >= frames_count) {
+               frames_count = 0;
+       } else {
+               std::copy(out_frames + skip, out_frames + frames_count, out_frames);
+               frames_count -= skip;
+       }
+    }
+#else
+    boost::stacktrace::detail::unwind_state state = { skip, out_frames, out_frames + max_frames_count };
     ::_Unwind_Backtrace(&boost::stacktrace::detail::unwind_callback, &state);
     frames_count = state.current - out_frames;
+#endif //defined(BOOST_STACKTRACE_USE_LIBC_BACKTRACE_FUNCTION)
 
     if (frames_count && out_frames[frames_count - 1] == 0) {
         -- frames_count;
@@ -69,4 +101,6 @@ std::size_t this_thread_frames::collect(native_frame_ptr_t* out_frames, std::siz
 
 }}} // namespace boost::stacktrace::detail
 
+#undef BOOST_STACKTRACE_USE_LIBC_BACKTRACE_FUNCTION
+
 #endif // BOOST_STACKTRACE_DETAIL_COLLECT_UNWIND_IPP