1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 * Copyright (C) 2017 Yusuke Suzuki <utatane.tea@gmail.com>
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#pragma once
28
29#include <wtf/Optional.h>
30#include <wtf/SystemFree.h>
31
32namespace WTF {
33
34class PrintStream;
35
36class StackTrace {
37 WTF_MAKE_FAST_ALLOCATED;
38public:
39 WTF_EXPORT_PRIVATE static std::unique_ptr<StackTrace> captureStackTrace(int maxFrames, int framesToSkip = 0);
40
41 // Borrowed stack trace.
42 StackTrace(void** stack, int size)
43 : m_size(size)
44 , m_capacity(0)
45 , m_borrowedStack(stack)
46 { }
47
48 int size() const { return m_size; }
49 void* const * stack() const
50 {
51 if (!m_capacity)
52 return m_borrowedStack;
53 return m_stack;
54 }
55
56 class DemangleEntry {
57 public:
58 friend class StackTrace;
59 const char* mangledName() const { return m_mangledName; }
60 const char* demangledName() const { return m_demangledName.get(); }
61
62 private:
63 DemangleEntry(const char* mangledName, const char* demangledName)
64 : m_mangledName(mangledName)
65 , m_demangledName(demangledName)
66 { }
67
68 const char* m_mangledName { nullptr };
69 std::unique_ptr<const char[], SystemFree<const char[]>> m_demangledName;
70 };
71
72 WTF_EXPORT_PRIVATE static Optional<DemangleEntry> demangle(void*);
73
74 WTF_EXPORT_PRIVATE void dump(PrintStream&, const char* indentString = nullptr) const;
75
76private:
77 inline static size_t instanceSize(int capacity);
78
79 StackTrace()
80 : m_size(0)
81 { }
82
83 // We structure the top fields this way because the underlying stack capture
84 // facility will capture from the top of the stack, and we'll need to skip the
85 // top 2 frame which is of no interest. Setting up the fields layout this way
86 // allows us to capture the stack in place and minimize space wastage.
87 union {
88 struct {
89 int m_size;
90 int m_capacity;
91 };
92 struct {
93 void* m_skippedFrame0;
94 void* m_skippedFrame1;
95 };
96 };
97 union {
98 void** m_borrowedStack;
99 void* m_stack[1];
100 };
101};
102
103} // namespace WTF
104
105using WTF::StackTrace;
106