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 LLDB_TARGET_STACKID_H
10 #define LLDB_TARGET_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() = default;
21 
22   explicit StackID(lldb::addr_t pc, lldb::addr_t cfa,
23                    SymbolContextScope *symbol_scope)
24       : m_pc(pc), m_cfa(cfa), m_symbol_scope(symbol_scope) {}
25 
26   StackID(const StackID &rhs)
27       : m_pc(rhs.m_pc), m_cfa(rhs.m_cfa), m_symbol_scope(rhs.m_symbol_scope) {}
28 
29   ~StackID() = default;
30 
31   lldb::addr_t GetPC() const { return m_pc; }
32 
33   lldb::addr_t GetCallFrameAddress() const { return m_cfa; }
34 
35   SymbolContextScope *GetSymbolContextScope() const { return m_symbol_scope; }
36 
37   void SetSymbolContextScope(SymbolContextScope *symbol_scope) {
38     m_symbol_scope = symbol_scope;
39   }
40 
41   void Clear() {
42     m_pc = LLDB_INVALID_ADDRESS;
43     m_cfa = LLDB_INVALID_ADDRESS;
44     m_symbol_scope = nullptr;
45   }
46 
47   bool IsValid() const {
48     return m_pc != LLDB_INVALID_ADDRESS || m_cfa != LLDB_INVALID_ADDRESS;
49   }
50 
51   void Dump(Stream *s);
52 
53   // Operators
54   const StackID &operator=(const StackID &rhs) {
55     if (this != &rhs) {
56       m_pc = rhs.m_pc;
57       m_cfa = rhs.m_cfa;
58       m_symbol_scope = rhs.m_symbol_scope;
59     }
60     return *this;
61   }
62 
63 protected:
64   friend class StackFrame;
65 
66   void SetPC(lldb::addr_t pc) { m_pc = pc; }
67 
68   void SetCFA(lldb::addr_t cfa) { m_cfa = cfa; }
69 
70   lldb::addr_t m_pc =
71       LLDB_INVALID_ADDRESS; // The pc value for the function/symbol for this
72                             // frame. This will
73   // only get used if the symbol scope is nullptr (the code where we are
74   // stopped is not represented by any function or symbol in any shared
75   // library).
76   lldb::addr_t m_cfa =
77       LLDB_INVALID_ADDRESS; // 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 *m_symbol_scope =
82       nullptr; // 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 // LLDB_TARGET_STACKID_H
100