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 virtual size_t GetRegisterSetCount() = 0;
35
36 virtual const RegisterSet *GetRegisterSet(size_t reg_set) = 0;
37
38 virtual lldb::ByteOrder GetByteOrder();
39
40 virtual bool ReadRegister(const RegisterInfo *reg_info,
41 RegisterValue &reg_value) = 0;
42
43 virtual bool WriteRegister(const RegisterInfo *reg_info,
44 const RegisterValue &reg_value) = 0;
45
46 virtual bool ReadAllRegisterValues(lldb::WritableDataBufferSP &data_sp) {
47 return false;
48 }
49
50 virtual bool WriteAllRegisterValues(const lldb::DataBufferSP &data_sp) {
51 return false;
52 }
53
54 virtual bool RegisterWriteCausesReconfigure(const llvm::StringRef name) {
55 return false;
56 }
57
58 virtual bool ReconfigureRegisterInfo() { return false; }
59
60 // These two functions are used to implement "push" and "pop" of register
61 // states. They are used primarily for expression evaluation, where we need
62 // to push a new state (storing the old one in data_sp) and then restoring
63 // the original state by passing the data_sp we got from ReadAllRegisters to
64 // WriteAllRegisterValues. ReadAllRegisters will do what is necessary to
65 // return a coherent set of register values for this thread, which may mean
66 // e.g. interrupting a thread that is sitting in a kernel trap. That is a
67 // somewhat disruptive operation, so these API's should only be used when
68 // this behavior is needed.
69
70 virtual bool
71 ReadAllRegisterValues(lldb_private::RegisterCheckpoint &reg_checkpoint);
72
73 virtual bool WriteAllRegisterValues(
74 const lldb_private::RegisterCheckpoint &reg_checkpoint);
75
76 bool CopyFromRegisterContext(lldb::RegisterContextSP context);
77
78 /// Convert from a given register numbering scheme to the lldb register
79 /// numbering scheme
80 ///
81 /// There may be multiple ways to enumerate the registers for a given
82 /// architecture. ABI references will specify one to be used with
83 /// DWARF, the register numberings from process plugin, there may
84 /// be a variation used for eh_frame unwind instructions (e.g. on Darwin),
85 /// and so on. Register 5 by itself is meaningless - RegisterKind
86 /// enumeration tells you what context that number should be translated as.
87 ///
88 /// Inside lldb, register numbers are in the eRegisterKindLLDB scheme;
89 /// arguments which take a register number should take one in that
90 /// scheme.
91 ///
92 /// eRegisterKindGeneric is a special numbering scheme which gives us
93 /// constant values for the pc, frame register, stack register, etc., for
94 /// use within lldb. They may not be defined for all architectures but
95 /// it allows generic code to translate these common registers into the
96 /// lldb numbering scheme.
97 ///
98 /// This method translates a given register kind + register number into
99 /// the eRegisterKindLLDB register numbering.
100 ///
101 /// \param [in] kind
102 /// The register numbering scheme (RegisterKind) that the following
103 /// register number is in.
104 ///
105 /// \param [in] num
106 /// A register number in the 'kind' register numbering scheme.
107 ///
108 /// \return
109 /// The equivalent register number in the eRegisterKindLLDB
110 /// numbering scheme, if possible, else LLDB_INVALID_REGNUM.
111 virtual uint32_t ConvertRegisterKindToRegisterNumber(lldb::RegisterKind kind,
112 uint32_t num);
113
114 // Subclasses can override these functions if desired
115 virtual uint32_t NumSupportedHardwareBreakpoints();
116
117 virtual uint32_t SetHardwareBreakpoint(lldb::addr_t addr, size_t size);
118
119 virtual bool ClearHardwareBreakpoint(uint32_t hw_idx);
120
121 virtual uint32_t NumSupportedHardwareWatchpoints();
122
123 virtual uint32_t SetHardwareWatchpoint(lldb::addr_t addr, size_t size,
124 bool read, bool write);
125
126 virtual bool ClearHardwareWatchpoint(uint32_t hw_index);
127
128 virtual bool HardwareSingleStep(bool enable);
129
130 virtual Status
131 ReadRegisterValueFromMemory(const lldb_private::RegisterInfo *reg_info,
132 lldb::addr_t src_addr, uint32_t src_len,
133 RegisterValue &reg_value);
134
135 virtual Status
136 WriteRegisterValueToMemory(const lldb_private::RegisterInfo *reg_info,
137 lldb::addr_t dst_addr, uint32_t dst_len,
138 const RegisterValue &reg_value);
139
140 // Subclasses should not override these
141 virtual lldb::tid_t GetThreadID() const;
142
143 virtual Thread &GetThread() { return m_thread; }
144
145 const RegisterInfo *GetRegisterInfoByName(llvm::StringRef reg_name,
146 uint32_t start_idx = 0);
147
148 const RegisterInfo *GetRegisterInfo(lldb::RegisterKind reg_kind,
149 uint32_t reg_num);
150
151 uint64_t GetPC(uint64_t fail_value = LLDB_INVALID_ADDRESS);
152
153 // Returns the register value containing thread specific data, like TLS data
154 // and other thread specific stuff.
155 uint64_t GetThreadPointer(uint64_t fail_value = LLDB_INVALID_ADDRESS);
156
157 /// Get an address suitable for symbolication.
158 /// When symbolicating -- computing line, block, function --
159 /// for a function in the middle of the stack, using the return
160 /// address can lead to unexpected results for the user.
161 /// A function that ends in a tail-call may have another function
162 /// as the "return" address, but it will never actually return.
163 /// Or a noreturn call in the middle of a function is the end of
164 /// a block of instructions, and a DWARF location list entry for
165 /// the return address may be a very different code path with
166 /// incorrect results when printing variables for this frame.
167 ///
168 /// At a source line view, the user expects the current-line indictation
169 /// to point to the function call they're under, not the next source line.
170 ///
171 /// The return address (GetPC()) should always be shown to the user,
172 /// but when computing context, keeping within the bounds of the
173 /// call instruction is what the user expects to see.
174 ///
175 /// \param [out] address
176 /// An Address object that will be filled in, if a PC can be retrieved.
177 ///
178 /// \return
179 /// Returns true if the Address param was filled in.
180 bool GetPCForSymbolication(Address &address);
181
182 bool SetPC(uint64_t pc);
183
184 bool SetPC(Address addr);
185
186 uint64_t GetSP(uint64_t fail_value = LLDB_INVALID_ADDRESS);
187
188 bool SetSP(uint64_t sp);
189
190 uint64_t GetFP(uint64_t fail_value = LLDB_INVALID_ADDRESS);
191
192 bool SetFP(uint64_t fp);
193
194 const char *GetRegisterName(uint32_t reg);
195
196 uint64_t GetReturnAddress(uint64_t fail_value = LLDB_INVALID_ADDRESS);
197
198 uint64_t GetFlags(uint64_t fail_value = 0);
199
200 uint64_t ReadRegisterAsUnsigned(uint32_t reg, uint64_t fail_value);
201
202 uint64_t ReadRegisterAsUnsigned(const RegisterInfo *reg_info,
203 uint64_t fail_value);
204
205 bool WriteRegisterFromUnsigned(uint32_t reg, uint64_t uval);
206
207 bool WriteRegisterFromUnsigned(const RegisterInfo *reg_info, uint64_t uval);
208
209 bool ConvertBetweenRegisterKinds(lldb::RegisterKind source_rk,
210 uint32_t source_regnum,
211 lldb::RegisterKind target_rk,
212 uint32_t &target_regnum);
213
214 // lldb::ExecutionContextScope pure virtual functions
215 lldb::TargetSP CalculateTarget() override;
216
217 lldb::ProcessSP CalculateProcess() override;
218
219 lldb::ThreadSP CalculateThread() override;
220
221 lldb::StackFrameSP CalculateStackFrame() override;
222
223 void CalculateExecutionContext(ExecutionContext &exe_ctx) override;
224
225 uint32_t GetStopID() const { return m_stop_id; }
226
227 void SetStopID(uint32_t stop_id) { m_stop_id = stop_id; }
228
229protected:
230 /// Indicates that this frame is currently executing code,
231 /// that the PC value is not a return-pc but an actual executing
232 /// instruction. Some places in lldb will treat a return-pc
233 /// value differently than the currently-executing-pc value,
234 /// and this method can indicate if that should be done.
235 /// The base class implementation only uses the frame index,
236 /// but subclasses may have additional information that they
237 /// can use to detect frames in this state, for instance a
238 /// frame above a trap handler (sigtramp etc)..
239 virtual bool BehavesLikeZerothFrame() const {
240 return m_concrete_frame_idx == 0;
241 }
242
243 // Classes that inherit from RegisterContext can see and modify these
244 Thread &m_thread; // The thread that this register context belongs to.
245 uint32_t m_concrete_frame_idx; // The concrete frame index for this register
246 // context
247 uint32_t m_stop_id; // The stop ID that any data in this context is valid for
248private:
249 // For RegisterContext only
250 RegisterContext(const RegisterContext &) = delete;
251 const RegisterContext &operator=(const RegisterContext &) = delete;
252};
253
254} // namespace lldb_private
255
256#endif // LLDB_TARGET_REGISTERCONTEXT_H
257

source code of lldb/include/lldb/Target/RegisterContext.h