1 //===-- StackID.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 liblldb_StackID_h_
10 #define liblldb_StackID_h_
11 
12 #include "lldb/Core/AddressRange.h"
13 #include "lldb/lldb-private.h"
14 
15 namespace lldb_private {
16 
17 class StackID {
18 public:
19   // Constructors and Destructors
20   StackID()
21       : m_pc(LLDB_INVALID_ADDRESS), m_cfa(LLDB_INVALID_ADDRESS),
22         m_symbol_scope(nullptr) {}
23 
24   explicit StackID(lldb::addr_t pc, lldb::addr_t cfa,
25                    SymbolContextScope *symbol_scope)
26       : m_pc(pc), m_cfa(cfa), m_symbol_scope(symbol_scope) {}
27 
28   StackID(const StackID &rhs)
29       : m_pc(rhs.m_pc), m_cfa(rhs.m_cfa), m_symbol_scope(rhs.m_symbol_scope) {}
30 
31   ~StackID() = default;
32 
33   lldb::addr_t GetPC() const { return m_pc; }
34 
35   lldb::addr_t GetCallFrameAddress() const { return m_cfa; }
36 
37   SymbolContextScope *GetSymbolContextScope() const { return m_symbol_scope; }
38 
39   void SetSymbolContextScope(SymbolContextScope *symbol_scope) {
40     m_symbol_scope = symbol_scope;
41   }
42 
43   void Clear() {
44     m_pc = LLDB_INVALID_ADDRESS;
45     m_cfa = LLDB_INVALID_ADDRESS;
46     m_symbol_scope = nullptr;
47   }
48 
49   bool IsValid() const {
50     return m_pc != LLDB_INVALID_ADDRESS || m_cfa != LLDB_INVALID_ADDRESS;
51   }
52 
53   void Dump(Stream *s);
54 
55   // Operators
56   const StackID &operator=(const StackID &rhs) {
57     if (this != &rhs) {
58       m_pc = rhs.m_pc;
59       m_cfa = rhs.m_cfa;
60       m_symbol_scope = rhs.m_symbol_scope;
61     }
62     return *this;
63   }
64 
65 protected:
66   friend class StackFrame;
67 
68   void SetPC(lldb::addr_t pc) { m_pc = pc; }
69 
70   void SetCFA(lldb::addr_t cfa) { m_cfa = cfa; }
71 
72   lldb::addr_t
73       m_pc; // The pc value for the function/symbol for this frame. This will
74   // only get used if the symbol scope is nullptr (the code where we are
75   // stopped is not represented by any function or symbol in any shared
76   // library).
77   lldb::addr_t m_cfa; // The call frame address (stack pointer) value
78                       // at the beginning of the function that uniquely
79                       // identifies this frame (along with m_symbol_scope
80                       // below)
81   SymbolContextScope *
82       m_symbol_scope; // If nullptr, there is no block or symbol for this frame.
83                       // If not nullptr, this will either be the scope for the
84                       // lexical block for the frame, or the scope for the
85                       // symbol. Symbol context scopes are always be unique
86                       // pointers since the are part of the Block and Symbol
87                       // objects and can easily be used to tell if a stack ID
88                       // is the same as another.
89 };
90 
91 bool operator==(const StackID &lhs, const StackID &rhs);
92 bool operator!=(const StackID &lhs, const StackID &rhs);
93 
94 // frame_id_1 < frame_id_2 means "frame_id_1 is YOUNGER than frame_id_2"
95 bool operator<(const StackID &lhs, const StackID &rhs);
96 
97 } // namespace lldb_private
98 
99 #endif // liblldb_StackID_h_
100