1//===-- UnixSignals.h -------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLDB_TARGET_UNIXSIGNALS_H
10#define LLDB_TARGET_UNIXSIGNALS_H
11
12#include <map>
13#include <optional>
14#include <string>
15#include <vector>
16
17#include "lldb/lldb-private.h"
18#include "llvm/Support/JSON.h"
19
20namespace lldb_private {
21
22class UnixSignals {
23public:
24  static lldb::UnixSignalsSP Create(const ArchSpec &arch);
25  static lldb::UnixSignalsSP CreateForHost();
26
27  // Constructors and Destructors
28  UnixSignals();
29
30  virtual ~UnixSignals();
31
32  llvm::StringRef GetSignalAsStringRef(int32_t signo) const;
33
34  std::string
35  GetSignalDescription(int32_t signo,
36                       std::optional<int32_t> code = std::nullopt,
37                       std::optional<lldb::addr_t> addr = std::nullopt,
38                       std::optional<lldb::addr_t> lower = std::nullopt,
39                       std::optional<lldb::addr_t> upper = std::nullopt) const;
40
41  bool SignalIsValid(int32_t signo) const;
42
43  int32_t GetSignalNumberFromName(const char *name) const;
44
45  /// Gets the information for a particular signal
46  ///
47  /// GetSignalInfo takes a signal number and populates 3 out parameters
48  /// describing how lldb should react when a particular signal is received in
49  /// the inferior.
50  ///
51  /// \param[in] signo
52  ///   The signal number to get information about.
53  /// \param[out] should_suppress
54  ///   Should we suppress this signal?
55  /// \param[out] should_stop
56  ///   Should we stop if this signal is received?
57  /// \param[out] should_notify
58  ///   Should we notify the user if this signal is received?
59  ///
60  /// \return
61  ///   Returns a boolean value. Returns true if the out parameters were
62  ///   successfully populated, false otherwise.
63  bool GetSignalInfo(int32_t signo, bool &should_suppress, bool &should_stop,
64                     bool &should_notify) const;
65
66  bool GetShouldSuppress(int32_t signo) const;
67
68  bool SetShouldSuppress(int32_t signo, bool value);
69
70  bool SetShouldSuppress(const char *signal_name, bool value);
71
72  bool GetShouldStop(int32_t signo) const;
73
74  bool SetShouldStop(int32_t signo, bool value);
75  bool SetShouldStop(const char *signal_name, bool value);
76
77  bool GetShouldNotify(int32_t signo) const;
78
79  bool SetShouldNotify(int32_t signo, bool value);
80
81  bool SetShouldNotify(const char *signal_name, bool value);
82
83  bool ResetSignal(int32_t signo, bool reset_stop = true,
84                   bool reset_notify = true, bool reset_suppress = true);
85
86  // These provide an iterator through the signals available on this system.
87  // Call GetFirstSignalNumber to get the first entry, then iterate on
88  // GetNextSignalNumber till you get back LLDB_INVALID_SIGNAL_NUMBER.
89  int32_t GetFirstSignalNumber() const;
90
91  int32_t GetNextSignalNumber(int32_t current_signal) const;
92
93  int32_t GetNumSignals() const;
94
95  int32_t GetSignalAtIndex(int32_t index) const;
96
97  // We assume that the elements of this object are constant once it is
98  // constructed, since a process should never need to add or remove symbols as
99  // it runs.  So don't call these functions anywhere but the constructor of
100  // your subclass of UnixSignals or in your Process Plugin's GetUnixSignals
101  // method before you return the UnixSignal object.
102
103  void AddSignal(int signo, llvm::StringRef name, bool default_suppress,
104                 bool default_stop, bool default_notify,
105                 llvm::StringRef description,
106                 llvm::StringRef alias = llvm::StringRef());
107
108  enum SignalCodePrintOption { None, Address, Bounds };
109
110  // Instead of calling this directly, use a ADD_SIGCODE macro to get compile
111  // time checks when on the native platform.
112  void AddSignalCode(
113      int signo, int code, const llvm::StringLiteral description,
114      SignalCodePrintOption print_option = SignalCodePrintOption::None);
115
116  void RemoveSignal(int signo);
117
118  /// Track how many times signals are hit as stop reasons.
119  void IncrementSignalHitCount(int signo);
120
121  /// Get the hit count statistics for signals.
122  ///
123  /// Gettings statistics on the hit counts of signals can help explain why some
124  /// debug sessions are slow since each stop takes a few hundred ms and some
125  /// software use signals a lot and can cause slow debugging performance if
126  /// they are used too often. Even if a signal is not stopped at, it will auto
127  /// continue the process and a delay will happen.
128  llvm::json::Value GetHitCountStatistics() const;
129
130  // Returns a current version of the data stored in this class. Version gets
131  // incremented each time Set... method is called.
132  uint64_t GetVersion() const;
133
134  // Returns a vector of signals that meet criteria provided in arguments. Each
135  // should_[suppress|stop|notify] flag can be std::nullopt - no filtering by
136  // this flag true - only signals that have it set to true are returned false -
137  // only signals that have it set to true are returned
138  std::vector<int32_t> GetFilteredSignals(std::optional<bool> should_suppress,
139                                          std::optional<bool> should_stop,
140                                          std::optional<bool> should_notify);
141
142protected:
143  // Classes that inherit from UnixSignals can see and modify these
144
145  struct SignalCode {
146    const llvm::StringLiteral m_description;
147    const SignalCodePrintOption m_print_option;
148  };
149
150  // The StringRefs in Signal are either backed by string literals or reside in
151  // persistent storage (e.g. a StringSet).
152  struct Signal {
153    llvm::StringRef m_name;
154    llvm::StringRef m_alias;
155    llvm::StringRef m_description;
156    std::map<int32_t, SignalCode> m_codes;
157    uint32_t m_hit_count = 0;
158    bool m_suppress : 1, m_stop : 1, m_notify : 1;
159    bool m_default_suppress : 1, m_default_stop : 1, m_default_notify : 1;
160
161    Signal(llvm::StringRef name, bool default_suppress, bool default_stop,
162           bool default_notify, llvm::StringRef description,
163           llvm::StringRef alias);
164
165    ~Signal() = default;
166    void Reset(bool reset_stop, bool reset_notify, bool reset_suppress);
167  };
168
169  llvm::StringRef GetShortName(llvm::StringRef name) const;
170
171  virtual void Reset();
172
173  typedef std::map<int32_t, Signal> collection;
174
175  collection m_signals;
176
177  // This version gets incremented every time something is changing in this
178  // class, including when we call AddSignal from the constructor. So after the
179  // object is constructed m_version is going to be > 0 if it has at least one
180  // signal registered in it.
181  uint64_t m_version = 0;
182
183  // GDBRemote signals need to be copyable.
184  UnixSignals(const UnixSignals &rhs);
185
186  const UnixSignals &operator=(const UnixSignals &rhs) = delete;
187};
188
189} // Namespace lldb
190#endif // LLDB_TARGET_UNIXSIGNALS_H
191