1//===-- Watchpoint.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_BREAKPOINT_WATCHPOINT_H
10#define LLDB_BREAKPOINT_WATCHPOINT_H
11
12#include <memory>
13#include <string>
14
15#include "lldb/Breakpoint/StoppointSite.h"
16#include "lldb/Breakpoint/WatchpointOptions.h"
17#include "lldb/Symbol/CompilerType.h"
18#include "lldb/Target/Target.h"
19#include "lldb/Utility/UserID.h"
20#include "lldb/lldb-private.h"
21
22namespace lldb_private {
23
24class Watchpoint : public std::enable_shared_from_this<Watchpoint>,
25                   public StoppointSite {
26public:
27  class WatchpointEventData : public EventData {
28  public:
29    WatchpointEventData(lldb::WatchpointEventType sub_type,
30                        const lldb::WatchpointSP &new_watchpoint_sp);
31
32    ~WatchpointEventData() override;
33
34    static ConstString GetFlavorString();
35
36    ConstString GetFlavor() const override;
37
38    lldb::WatchpointEventType GetWatchpointEventType() const;
39
40    lldb::WatchpointSP &GetWatchpoint();
41
42    void Dump(Stream *s) const override;
43
44    static lldb::WatchpointEventType
45    GetWatchpointEventTypeFromEvent(const lldb::EventSP &event_sp);
46
47    static lldb::WatchpointSP
48    GetWatchpointFromEvent(const lldb::EventSP &event_sp);
49
50    static const WatchpointEventData *
51    GetEventDataFromEvent(const Event *event_sp);
52
53  private:
54    lldb::WatchpointEventType m_watchpoint_event;
55    lldb::WatchpointSP m_new_watchpoint_sp;
56
57    WatchpointEventData(const WatchpointEventData &) = delete;
58    const WatchpointEventData &operator=(const WatchpointEventData &) = delete;
59  };
60
61  Watchpoint(Target &target, lldb::addr_t addr, uint32_t size,
62             const CompilerType *type, bool hardware = true);
63
64  ~Watchpoint() override;
65
66  void IncrementFalseAlarmsAndReviseHitCount();
67
68  bool IsEnabled() const;
69
70  // This doesn't really enable/disable the watchpoint.   It is currently just
71  // for use in the Process plugin's {Enable,Disable}Watchpoint, which should
72  // be used instead.
73  void SetEnabled(bool enabled, bool notify = true);
74
75  bool IsHardware() const override;
76
77  bool ShouldStop(StoppointCallbackContext *context) override;
78
79  bool WatchpointRead() const;
80  bool WatchpointWrite() const;
81  uint32_t GetIgnoreCount() const;
82  void SetIgnoreCount(uint32_t n);
83  void SetWatchpointType(uint32_t type, bool notify = true);
84  void SetDeclInfo(const std::string &str);
85  std::string GetWatchSpec();
86  void SetWatchSpec(const std::string &str);
87
88  // Snapshot management interface.
89  bool IsWatchVariable() const;
90  void SetWatchVariable(bool val);
91  bool CaptureWatchedValue(const ExecutionContext &exe_ctx);
92
93  void GetDescription(Stream *s, lldb::DescriptionLevel level);
94  void Dump(Stream *s) const override;
95  void DumpSnapshots(Stream *s, const char *prefix = nullptr) const;
96  void DumpWithLevel(Stream *s, lldb::DescriptionLevel description_level) const;
97  Target &GetTarget() { return m_target; }
98  const Status &GetError() { return m_error; }
99
100  /// Returns the WatchpointOptions structure set for this watchpoint.
101  ///
102  /// \return
103  ///     A pointer to this watchpoint's WatchpointOptions.
104  WatchpointOptions *GetOptions() { return &m_options; }
105
106  /// Set the callback action invoked when the watchpoint is hit.
107  ///
108  /// \param[in] callback
109  ///    The method that will get called when the watchpoint is hit.
110  /// \param[in] callback_baton
111  ///    A void * pointer that will get passed back to the callback function.
112  /// \param[in] is_synchronous
113  ///    If \b true the callback will be run on the private event thread
114  ///    before the stop event gets reported.  If false, the callback will get
115  ///    handled on the public event thread after the stop has been posted.
116  void SetCallback(WatchpointHitCallback callback, void *callback_baton,
117                   bool is_synchronous = false);
118
119  void SetCallback(WatchpointHitCallback callback,
120                   const lldb::BatonSP &callback_baton_sp,
121                   bool is_synchronous = false);
122
123  void ClearCallback();
124
125  /// Invoke the callback action when the watchpoint is hit.
126  ///
127  /// \param[in] context
128  ///     Described the watchpoint event.
129  ///
130  /// \return
131  ///     \b true if the target should stop at this watchpoint and \b false not.
132  bool InvokeCallback(StoppointCallbackContext *context);
133
134  // Condition
135  /// Set the watchpoint's condition.
136  ///
137  /// \param[in] condition
138  ///    The condition expression to evaluate when the watchpoint is hit.
139  ///    Pass in nullptr to clear the condition.
140  void SetCondition(const char *condition);
141
142  /// Return a pointer to the text of the condition expression.
143  ///
144  /// \return
145  ///    A pointer to the condition expression text, or nullptr if no
146  //     condition has been set.
147  const char *GetConditionText() const;
148
149  void TurnOnEphemeralMode();
150
151  void TurnOffEphemeralMode();
152
153  bool IsDisabledDuringEphemeralMode();
154
155  const CompilerType &GetCompilerType() { return m_type; }
156
157private:
158  friend class Target;
159  friend class WatchpointList;
160  friend class StopInfoWatchpoint; // This needs to call UndoHitCount()
161
162  void ResetHistoricValues() {
163    m_old_value_sp.reset();
164    m_new_value_sp.reset();
165  }
166
167  void UndoHitCount() { m_hit_counter.Decrement(); }
168
169  Target &m_target;
170  bool m_enabled;           // Is this watchpoint enabled
171  bool m_is_hardware;       // Is this a hardware watchpoint
172  bool m_is_watch_variable; // True if set via 'watchpoint set variable'.
173  bool m_is_ephemeral;      // True if the watchpoint is in the ephemeral mode,
174                            // meaning that it is
175  // undergoing a pair of temporary disable/enable actions to avoid recursively
176  // triggering further watchpoint events.
177  uint32_t m_disabled_count; // Keep track of the count that the watchpoint is
178                             // disabled while in ephemeral mode.
179  // At the end of the ephemeral mode when the watchpoint is to be enabled
180  // again, we check the count, if it is more than 1, it means the user-
181  // supplied actions actually want the watchpoint to be disabled!
182  uint32_t m_watch_read : 1, // 1 if we stop when the watched data is read from
183      m_watch_write : 1,     // 1 if we stop when the watched data is written to
184      m_watch_was_read : 1, // Set to 1 when watchpoint is hit for a read access
185      m_watch_was_written : 1;  // Set to 1 when watchpoint is hit for a write
186                                // access
187  uint32_t m_ignore_count;      // Number of times to ignore this watchpoint
188  uint32_t m_false_alarms;      // Number of false alarms.
189  std::string m_decl_str;       // Declaration information, if any.
190  std::string m_watch_spec_str; // Spec for the watchpoint.
191  lldb::ValueObjectSP m_old_value_sp;
192  lldb::ValueObjectSP m_new_value_sp;
193  CompilerType m_type;
194  Status m_error; // An error object describing errors associated with this
195                  // watchpoint.
196  WatchpointOptions
197      m_options; // Settable watchpoint options, which is a delegate to handle
198                 // the callback machinery.
199  bool m_being_created;
200
201  std::unique_ptr<UserExpression> m_condition_up; // The condition to test.
202
203  void SetID(lldb::watch_id_t id) { m_id = id; }
204
205  void SendWatchpointChangedEvent(lldb::WatchpointEventType eventKind);
206
207  void SendWatchpointChangedEvent(WatchpointEventData *data);
208
209  Watchpoint(const Watchpoint &) = delete;
210  const Watchpoint &operator=(const Watchpoint &) = delete;
211};
212
213} // namespace lldb_private
214
215#endif // LLDB_BREAKPOINT_WATCHPOINT_H
216