1//===-- RegisterContext.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_REGISTERCONTEXT_H
10#define LLDB_TARGET_REGISTERCONTEXT_H
11
12#include "lldb/Target/ExecutionContextScope.h"
13#include "lldb/lldb-private.h"
14
15namespace lldb_private {
16
17class RegisterContext : public std::enable_shared_from_this<RegisterContext>,
18 public ExecutionContextScope {
19public:
20 // Constructors and Destructors
21 RegisterContext(Thread &thread, uint32_t concrete_frame_idx);
22
23 ~RegisterContext() override;
24
25 void InvalidateIfNeeded(bool force);
26
27 // Subclasses must override these functions
28 virtual void InvalidateAllRegisters() = 0;
29
30 virtual size_t GetRegisterCount() = 0;
31
32 virtual const RegisterInfo *GetRegisterInfoAtIndex(size_t reg) = 0;
33
34 // Detect the register size dynamically.
35 uint32_t UpdateDynamicRegisterSize(const lldb_private::ArchSpec &arch,
36 RegisterInfo *reg_info);
37
38 virtual size_t GetRegisterSetCount() = 0;
39
40 virtual const RegisterSet *GetRegisterSet(size_t reg_set) = 0;
41
42 virtual lldb::ByteOrder GetByteOrder();
43
44 virtual bool ReadRegister(const RegisterInfo *reg_info,
45 RegisterValue &reg_value) = 0;
46
47 virtual bool WriteRegister(const RegisterInfo *reg_info,
48 const RegisterValue &reg_value) = 0;
49
50 virtual bool ReadAllRegisterValues(lldb::DataBufferSP &data_sp) {
51 return false;
52 }
53
54 virtual bool WriteAllRegisterValues(const lldb::DataBufferSP &data_sp) {
55 return false;
56 }
57
58 // These two functions are used to implement "push" and "pop" of register
59 // states. They are used primarily for expression evaluation, where we need
60 // to push a new state (storing the old one in data_sp) and then restoring
61 // the original state by passing the data_sp we got from ReadAllRegisters to
62 // WriteAllRegisterValues. ReadAllRegisters will do what is necessary to
63 // return a coherent set of register values for this thread, which may mean
64 // e.g. interrupting a thread that is sitting in a kernel trap. That is a
65 // somewhat disruptive operation, so these API's should only be used when
66 // this behavior is needed.
67
68 virtual bool
69 ReadAllRegisterValues(lldb_private::RegisterCheckpoint &reg_checkpoint);
70
71 virtual bool WriteAllRegisterValues(
72 const lldb_private::RegisterCheckpoint &reg_checkpoint);
73
74 bool CopyFromRegisterContext(lldb::RegisterContextSP context);
75
76 /// Convert from a given register numbering scheme to the lldb register
77 /// numbering scheme
78 ///
79 /// There may be multiple ways to enumerate the registers for a given
80 /// architecture. ABI references will specify one to be used with
81 /// DWARF, the register numberings from process plugin, there may
82 /// be a variation used for eh_frame unwind instructions (e.g. on Darwin),
83 /// and so on. Register 5 by itself is meaningless - RegisterKind
84 /// enumeration tells you what context that number should be translated as.
85 ///
86 /// Inside lldb, register numbers are in the eRegisterKindLLDB scheme;
87 /// arguments which take a register number should take one in that
88 /// scheme.
89 ///
90 /// eRegisterKindGeneric is a special numbering scheme which gives us
91 /// constant values for the pc, frame register, stack register, etc., for
92 /// use within lldb. They may not be defined for all architectures but
93 /// it allows generic code to translate these common registers into the
94 /// lldb numbering scheme.
95 ///
96 /// This method translates a given register kind + register number into
97 /// the eRegisterKindLLDB register numbering.
98 ///
99 /// \param [in] kind
100 /// The register numbering scheme (RegisterKind) that the following
101 /// register number is in.
102 ///
103 /// \param [in] num
104 /// A register number in the 'kind' register numbering scheme.
105 ///
106 /// \return
107 /// The equivalent register number in the eRegisterKindLLDB
108 /// numbering scheme, if possible, else LLDB_INVALID_REGNUM.
109 virtual uint32_t ConvertRegisterKindToRegisterNumber(lldb::RegisterKind kind,
110 uint32_t num);
111
112 // Subclasses can override these functions if desired
113 virtual uint32_t NumSupportedHardwareBreakpoints();
114
115 virtual uint32_t SetHardwareBreakpoint(lldb::addr_t addr, size_t size);
116
117 virtual bool ClearHardwareBreakpoint(uint32_t hw_idx);
118
119 virtual uint32_t NumSupportedHardwareWatchpoints();
120
121 virtual uint32_t SetHardwareWatchpoint(lldb::addr_t addr, size_t size,
122 bool read, bool write);
123
124 virtual bool ClearHardwareWatchpoint(uint32_t hw_index);
125
126 virtual bool HardwareSingleStep(bool enable);
127
128 virtual Status
129 ReadRegisterValueFromMemory(const lldb_private::RegisterInfo *reg_info,
130 lldb::addr_t src_addr, uint32_t src_len,
131 RegisterValue &reg_value);
132
133 virtual Status
134 WriteRegisterValueToMemory(const lldb_private::RegisterInfo *reg_info,
135 lldb::addr_t dst_addr, uint32_t dst_len,
136 const RegisterValue &reg_value);
137
138 // Subclasses should not override these
139 virtual lldb::tid_t GetThreadID() const;
140
141 virtual Thread &GetThread() { return m_thread; }
142
143 const RegisterInfo *GetRegisterInfoByName(llvm::StringRef reg_name,
144 uint32_t start_idx = 0);
145
146 const RegisterInfo *GetRegisterInfo(lldb::RegisterKind reg_kind,
147 uint32_t reg_num);
148
149 uint64_t GetPC(uint64_t fail_value = LLDB_INVALID_ADDRESS);
150
151 /// Get an address suitable for symbolication.
152 /// When symbolicating -- computing line, block, function --
153 /// for a function in the middle of the stack, using the return
154 /// address can lead to unexpected results for the user.
155 /// A function that ends in a tail-call may have another function
156 /// as the "return" address, but it will never actually return.
157 /// Or a noreturn call in the middle of a function is the end of
158 /// a block of instructions, and a DWARF location list entry for
159 /// the return address may be a very different code path with
160 /// incorrect results when printing variables for this frame.
161 ///
162 /// At a source line view, the user expects the current-line indictation
163 /// to point to the function call they're under, not the next source line.
164 ///
165 /// The return address (GetPC()) should always be shown to the user,
166 /// but when computing context, keeping within the bounds of the
167 /// call instruction is what the user expects to see.
168 ///
169 /// \param [out] address
170 /// An Address object that will be filled in, if a PC can be retrieved.
171 ///
172 /// \return
173 /// Returns true if the Address param was filled in.
174 bool GetPCForSymbolication(Address &address);
175
176 bool SetPC(uint64_t pc);
177
178 bool SetPC(Address addr);
179
180 uint64_t GetSP(uint64_t fail_value = LLDB_INVALID_ADDRESS);
181
182 bool SetSP(uint64_t sp);
183
184 uint64_t GetFP(uint64_t fail_value = LLDB_INVALID_ADDRESS);
185
186 bool SetFP(uint64_t fp);
187
188 const char *GetRegisterName(uint32_t reg);
189
190 uint64_t GetReturnAddress(uint64_t fail_value = LLDB_INVALID_ADDRESS);
191
192 uint64_t GetFlags(uint64_t fail_value = 0);
193
194 uint64_t ReadRegisterAsUnsigned(uint32_t reg, uint64_t fail_value);
195
196 uint64_t ReadRegisterAsUnsigned(const RegisterInfo *reg_info,
197 uint64_t fail_value);
198
199 bool WriteRegisterFromUnsigned(uint32_t reg, uint64_t uval);
200
201 bool WriteRegisterFromUnsigned(const RegisterInfo *reg_info, uint64_t uval);
202
203 bool ConvertBetweenRegisterKinds(lldb::RegisterKind source_rk,
204 uint32_t source_regnum,
205 lldb::RegisterKind target_rk,
206 uint32_t &target_regnum);
207
208 // lldb::ExecutionContextScope pure virtual functions
209 lldb::TargetSP CalculateTarget() override;
210
211 lldb::ProcessSP CalculateProcess() override;
212
213 lldb::ThreadSP CalculateThread() override;
214
215 lldb::StackFrameSP CalculateStackFrame() override;
216
217 void CalculateExecutionContext(ExecutionContext &exe_ctx) override;
218
219 uint32_t GetStopID() const { return m_stop_id; }
220
221 void SetStopID(uint32_t stop_id) { m_stop_id = stop_id; }
222
223protected:
224 /// Indicates that this frame is currently executing code,
225 /// that the PC value is not a return-pc but an actual executing
226 /// instruction. Some places in lldb will treat a return-pc
227 /// value differently than the currently-executing-pc value,
228 /// and this method can indicate if that should be done.
229 /// The base class implementation only uses the frame index,
230 /// but subclasses may have additional information that they
231 /// can use to detect frames in this state, for instance a
232 /// frame above a trap handler (sigtramp etc)..
233 virtual bool BehavesLikeZerothFrame() const {
234 return m_concrete_frame_idx == 0;
235 }
236
237 // Classes that inherit from RegisterContext can see and modify these
238 Thread &m_thread; // The thread that this register context belongs to.
239 uint32_t m_concrete_frame_idx; // The concrete frame index for this register
240 // context
241 uint32_t m_stop_id; // The stop ID that any data in this context is valid for
242private:
243 // For RegisterContext only
244 RegisterContext(const RegisterContext &) = delete;
245 const RegisterContext &operator=(const RegisterContext &) = delete;
246};
247
248} // namespace lldb_private
249
250#endif // LLDB_TARGET_REGISTERCONTEXT_H
251