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 15 namespace lldb_private { 16 17 class RegisterContext : public std::enable_shared_from_this<RegisterContext>, 18 public ExecutionContextScope { 19 public: 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 ®_value) = 0; 46 47 virtual bool WriteRegister(const RegisterInfo *reg_info, 48 const RegisterValue ®_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 ®_checkpoint); 70 71 virtual bool WriteAllRegisterValues( 72 const lldb_private::RegisterCheckpoint ®_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 ®_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 ®_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; } 222 223 protected: 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 242 private: 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