1 /*
2  * Copyright (c) Facebook, Inc. and its affiliates.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 //
18 // Exception tracer library.
19 
20 #pragma once
21 
22 #include <cstdint>
23 #include <iosfwd>
24 #include <typeinfo>
25 #include <vector>
26 
27 #include <folly/portability/Config.h>
28 
29 #if FOLLY_HAVE_ELF && FOLLY_HAVE_DWARF
30 
31 namespace folly {
32 namespace exception_tracer {
33 
34 struct ExceptionInfo {
35   const std::type_info* type{nullptr};
36   // The values in frames are IP (instruction pointer) addresses.
37   // They are only filled if the low-level exception tracer library is
38   // linked in or LD_PRELOADed.
39   std::vector<uintptr_t> frames; // front() is top of stack
40 };
41 
42 void printExceptionInfo(
43     std::ostream& out, const ExceptionInfo& info, int options);
44 std::ostream& operator<<(std::ostream& out, const ExceptionInfo& info);
45 
46 /**
47  * Get current exceptions being handled.  front() is the most recent exception.
48  * There should be at most one unless rethrowing.
49  */
50 std::vector<ExceptionInfo> getCurrentExceptions();
51 
52 /**
53  * Install the terminate / unexpected handlers to dump exceptions.
54  */
55 void installHandlers();
56 
57 } // namespace exception_tracer
58 } // namespace folly
59 
60 #endif // FOLLY_HAVE_ELF && FOLLY_HAVE_DWARF
61