From 5647d5ee8e426edd18dbc5765a32951a6c7efdcf Mon Sep 17 00:00:00 2001
From: Kefu Chai <kchai@redhat.com>
Date: Thu, 19 Jan 2017 12:36:06 +0800
Subject: [PATCH] common/BackTrace: demangle on FreeBSD also

the output on FreeBSD/clang looks like:

1: 0x44bfb3 <_Z3foov+0x413> at /usr/srcs/Ceph/work/ceph/build/bin/unittest_back_trace
2: 0x44c23e <_ZN20BackTrace_Basic_Test8TestBodyEv+0x1e> at /usr/srcs/Ceph/work/ceph/build/bin/unittest_back_trace
3: 0x4d068a <_ZN7testing8internal38HandleSehExceptionsInMethodIfSupportedINS_4TestEvEET0_PT_MS4_FS3_vEPKc+0x7a> at /usr/srcs/Ceph/work/ceph/build/bin/unittest_back_trace
4: 0x4b5977 <_ZN7testing8internal35HandleExceptionsInMethodIfSupportedINS_4TestEvEET0_PT_MS4_FS3_vEPKc+0x77> at /usr/srcs/Ceph/work/ceph/build/bin/unittest_back_trace
...

and update the test accordingly, as FreeBSD/clang uses '<>' to enclose
the mangled function and offset.

also, only demangle the C++ mangled names. those names always start with
"_Z". on FreeBSD, after demangling, "main" is turned into "unsigned
long", which does not make sense.

Signed-off-by: Kefu Chai <kchai@redhat.com>
---
 src/common/BackTrace.cc            | 14 +++++++++++---
 src/rocksdb                        |  2 +-
 src/test/common/test_back_trace.cc |  7 ++++++-
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/common/BackTrace.cc b/src/common/BackTrace.cc
index 33408f33d448a..5fc6311d52892 100644
--- a/src/common/BackTrace.cc
+++ b/src/common/BackTrace.cc
@@ -27,8 +27,13 @@ void BackTrace::print(std::ostream& out) const
     char *begin = 0, *end = 0;
     
     // find the parentheses and address offset surrounding the mangled name
+#ifdef __FreeBSD__
+    static constexpr char OPEN = '<';
+#else
+    static constexpr char OPEN = '(';
+#endif
     for (char *j = strings[i]; *j; ++j) {
-      if (*j == '(')
+      if (*j == OPEN)
 	begin = j+1;
       else if (*j == '+')
 	end = j;
@@ -44,7 +49,10 @@ void BackTrace::print(std::ostream& out) const
       foo[len] = 0;
 
       int status;
-      char *ret = abi::__cxa_demangle(foo, function, &sz, &status);
+      char *ret = nullptr;
+      // only demangle a C++ mangled name
+      if (foo[0] == '_' && foo[1] == 'Z')
+	ret = abi::__cxa_demangle(foo, function, &sz, &status);
       if (ret) {
 	// return value may be a realloc() of the input
 	function = ret;
@@ -55,7 +63,7 @@ void BackTrace::print(std::ostream& out) const
 	strncat(function, "()", sz);
 	function[sz-1] = 0;
       }
-      out << " " << (i-skip+1) << ": (" << function << end << std::endl;
+      out << " " << (i-skip+1) << ": " << OPEN << function << end << std::endl;
       //fprintf(out, "    %s:%s\n", stack.strings[i], function);
       free(foo);
     } else {
diff --git a/src/rocksdb b/src/rocksdb
index a9b0a54f4925a..a0deec960f3a8 160000
--- a/src/rocksdb
+++ b/src/rocksdb
@@ -1 +1 @@
-Subproject commit a9b0a54f4925a5a48c70fc19257af988acebcea9
+Subproject commit a0deec960f3a8190831c673e5ba998fe6fb7ea90
diff --git a/src/test/common/test_back_trace.cc b/src/test/common/test_back_trace.cc
index 389f4e3de3af9..ff626f5a4c4fd 100644
--- a/src/test/common/test_back_trace.cc
+++ b/src/test/common/test_back_trace.cc
@@ -33,9 +33,14 @@ TEST(BackTrace, Basic) {
   boost::split(lines, bt, boost::is_any_of("\n"));
   const unsigned lineno = 1;
   ASSERT_GT(lines.size(), lineno);
-  ASSERT_EQ(lines[0].find(pretty_version_to_str()), 1);
+  ASSERT_EQ(lines[0].find(pretty_version_to_str()), 1U);
   boost::regex e{"^ 1: "
+#ifdef __FreeBSD__
+		 "<foo.*>\\s"
+		 "at\\s.*$"};
+#else
 		 "\\(foo.*\\)\\s"
 		 "\\[0x[[:xdigit:]]+\\]$"};
+#endif
   EXPECT_TRUE(boost::regex_match(lines[lineno], e));
 }
-- 
2.47.3