1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// Slightly adapted for inclusion in V8.
6// Copyright 2016 the V8 project authors. All rights reserved.
7
8#include "src/base/debug/stack_trace.h"
9
10#include <signal.h>
11#include <stddef.h>
12#include <string.h>
13#include <unwind.h>
14
15#include <src/base/platform/platform.h>
16
17#include <iomanip>
18#include <ostream>
19
20namespace {
21
22struct StackCrawlState {
23  StackCrawlState(uintptr_t* frames, size_t max_depth)
24      : frames(frames),
25        frame_count(0),
26        max_depth(max_depth),
27        have_skipped_self(false) {}
28
29  uintptr_t* frames;
30  size_t frame_count;
31  size_t max_depth;
32  bool have_skipped_self;
33};
34
35_Unwind_Reason_Code TraceStackFrame(_Unwind_Context* context, void* arg) {
36  StackCrawlState* state = static_cast<StackCrawlState*>(arg);
37  uintptr_t ip = _Unwind_GetIP(context);
38
39  // The first stack frame is this function itself.  Skip it.
40  if (ip != 0 && !state->have_skipped_self) {
41    state->have_skipped_self = true;
42    return _URC_NO_REASON;
43  }
44
45  state->frames[state->frame_count++] = ip;
46  if (state->frame_count >= state->max_depth)
47    return _URC_END_OF_STACK;
48  return _URC_NO_REASON;
49}
50
51}  // namespace
52
53namespace v8 {
54namespace base {
55namespace debug {
56
57bool EnableInProcessStackDumping() {
58  // When running in an application, our code typically expects SIGPIPE
59  // to be ignored.  Therefore, when testing that same code, it should run
60  // with SIGPIPE ignored as well.
61  // TODO(phajdan.jr): De-duplicate this SIGPIPE code.
62  struct sigaction action;
63  memset(&action, 0, sizeof(action));
64  action.sa_handler = SIG_IGN;
65  sigemptyset(&action.sa_mask);
66  return (sigaction(SIGPIPE, &action, NULL) == 0);
67}
68
69void DisableSignalStackDump() {
70}
71
72StackTrace::StackTrace() {
73  StackCrawlState state(reinterpret_cast<uintptr_t*>(trace_), kMaxTraces);
74  _Unwind_Backtrace(&TraceStackFrame, &state);
75  count_ = state.frame_count;
76}
77
78void StackTrace::Print() const {
79  std::string backtrace = ToString();
80  OS::Print("%s\n", backtrace.c_str());
81}
82
83void StackTrace::OutputToStream(std::ostream* os) const {
84  for (size_t i = 0; i < count_; ++i) {
85    *os << "#" << std::setw(2) << i << trace_[i] << "\n";
86  }
87}
88
89}  // namespace debug
90}  // namespace base
91}  // namespace v8
92