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