1 //===-- RegisterContextLLDB.h --------------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef lldb_RegisterContextLLDB_h_ 11 #define lldb_RegisterContextLLDB_h_ 12 13 #include <vector> 14 15 #include "lldb/lldb-private.h" 16 #include "lldb/Target/RegisterContext.h" 17 #include "lldb/Symbol/UnwindPlan.h" 18 #include "lldb/Symbol/SymbolContext.h" 19 #include "UnwindLLDB.h" 20 21 namespace lldb_private { 22 23 class UnwindLLDB; 24 25 class RegisterContextLLDB : public lldb_private::RegisterContext 26 { 27 public: 28 typedef std::shared_ptr<RegisterContextLLDB> SharedPtr; 29 30 RegisterContextLLDB (lldb_private::Thread &thread, 31 const SharedPtr& next_frame, 32 lldb_private::SymbolContext& sym_ctx, 33 uint32_t frame_number, lldb_private::UnwindLLDB& unwind_lldb); 34 35 /// 36 // pure virtual functions from the base class that we must implement 37 /// 38 39 virtual 40 ~RegisterContextLLDB () { } 41 42 virtual void 43 InvalidateAllRegisters (); 44 45 virtual size_t 46 GetRegisterCount (); 47 48 virtual const lldb_private::RegisterInfo * 49 GetRegisterInfoAtIndex (size_t reg); 50 51 virtual size_t 52 GetRegisterSetCount (); 53 54 virtual const lldb_private::RegisterSet * 55 GetRegisterSet (size_t reg_set); 56 57 virtual bool 58 ReadRegister (const lldb_private::RegisterInfo *reg_info, lldb_private::RegisterValue &value); 59 60 virtual bool 61 WriteRegister (const lldb_private::RegisterInfo *reg_info, const lldb_private::RegisterValue &value); 62 63 virtual bool 64 ReadAllRegisterValues (lldb::DataBufferSP &data_sp); 65 66 virtual bool 67 WriteAllRegisterValues (const lldb::DataBufferSP &data_sp); 68 69 virtual uint32_t 70 ConvertRegisterKindToRegisterNumber (uint32_t kind, uint32_t num); 71 72 bool 73 IsValid () const; 74 75 bool 76 GetCFA (lldb::addr_t& cfa); 77 78 bool 79 GetStartPC (lldb::addr_t& start_pc); 80 81 bool 82 ReadPC (lldb::addr_t& start_pc); 83 84 private: 85 86 enum FrameType 87 { 88 eNormalFrame, 89 eSigtrampFrame, 90 eDebuggerFrame, // a debugger inferior function call frame; we get caller's registers from debugger 91 eSkipFrame, // The unwind resulted in a bogus frame but may get back on track so we don't want to give up yet 92 eNotAValidFrame // this frame is invalid for some reason - most likely it is past the top (end) of the stack 93 }; 94 95 // UnwindLLDB needs to pass around references to RegisterLocations 96 friend class UnwindLLDB; 97 98 // Indicates whether this frame is frame zero -- the currently 99 // executing frame -- or not. 100 bool 101 IsFrameZero () const; 102 103 void 104 InitializeZerothFrame (); 105 106 void 107 InitializeNonZerothFrame(); 108 109 SharedPtr 110 GetNextFrame () const; 111 112 SharedPtr 113 GetPrevFrame () const; 114 115 // A SkipFrame occurs when the unwind out of frame 0 didn't go right -- we've got one bogus frame at frame #1. 116 // There is a good chance we'll get back on track if we follow the frame pointer chain (or whatever is appropriate 117 // on this ABI) so we allow one invalid frame to be in the stack. Ideally we'll mark this frame specially at some 118 // point and indicate to the user that the unwinder had a hiccup. Often when this happens we will miss a frame of 119 // the program's actual stack in the unwind and we want to flag that for the user somehow. 120 bool 121 IsSkipFrame () const; 122 123 // Provide a location for where THIS function saved the CALLER's register value 124 // Or a frame "below" this one saved it, i.e. a function called by this one, preserved a register that this 125 // function didn't modify/use. 126 // 127 // The RegisterLocation type may be set to eRegisterNotAvailable -- this will happen for a volatile register 128 // being queried mid-stack. Instead of floating frame 0's contents of that register up the stack (which may 129 // or may not be the value of that reg when the function was executing), we won't return any value. 130 // 131 // If a non-volatile register (a "preserved" register) is requested mid-stack and no frames "below" the requested 132 // stack have saved the register anywhere, it is safe to assume that frame 0's register values are still the same 133 // as the requesting frame's. 134 lldb_private::UnwindLLDB::RegisterSearchResult 135 SavedLocationForRegister (uint32_t lldb_regnum, lldb_private::UnwindLLDB::RegisterLocation ®loc); 136 137 bool 138 ReadRegisterValueFromRegisterLocation (lldb_private::UnwindLLDB::RegisterLocation regloc, 139 const lldb_private::RegisterInfo *reg_info, 140 lldb_private::RegisterValue &value); 141 142 bool 143 WriteRegisterValueToRegisterLocation (lldb_private::UnwindLLDB::RegisterLocation regloc, 144 const lldb_private::RegisterInfo *reg_info, 145 const lldb_private::RegisterValue &value); 146 147 void 148 InvalidateFullUnwindPlan (); 149 150 // Get the contents of a general purpose (address-size) register for this frame 151 // (usually retrieved from the next frame) 152 bool 153 ReadGPRValue (int register_kind, uint32_t regnum, lldb::addr_t &value); 154 155 lldb::UnwindPlanSP 156 GetFastUnwindPlanForFrame (); 157 158 lldb::UnwindPlanSP 159 GetFullUnwindPlanForFrame (); 160 161 void 162 UnwindLogMsg (const char *fmt, ...) __attribute__ ((format (printf, 2, 3))); 163 164 void 165 UnwindLogMsgVerbose (const char *fmt, ...) __attribute__ ((format (printf, 2, 3))); 166 167 lldb_private::Thread& m_thread; 168 169 /// 170 // The following tell us how to retrieve the CALLER's register values (ie the "previous" frame, aka the frame above) 171 // i.e. where THIS frame saved them 172 /// 173 174 lldb::UnwindPlanSP m_fast_unwind_plan_sp; // may be NULL 175 lldb::UnwindPlanSP m_full_unwind_plan_sp; 176 bool m_all_registers_available; // Can we retrieve all regs or just nonvolatile regs? 177 int m_frame_type; // enum FrameType 178 179 lldb::addr_t m_cfa; 180 lldb_private::Address m_start_pc; 181 lldb_private::Address m_current_pc; 182 183 int m_current_offset; // how far into the function we've executed; -1 if unknown 184 // 0 if no instructions have been executed yet. 185 186 int m_current_offset_backed_up_one; // how far into the function we've executed; -1 if unknown 187 // 0 if no instructions have been executed yet. 188 // On architectures where the return address on the stack points 189 // to the instruction after the CALL, this value will have 1 190 // subtracted from it. Else a function that ends in a CALL will 191 // have an offset pointing into the next function's address range. 192 // m_current_pc has the actual address of the "current" pc. 193 194 lldb_private::SymbolContext& m_sym_ctx; 195 bool m_sym_ctx_valid; // if ResolveSymbolContextForAddress fails, don't try to use m_sym_ctx 196 197 uint32_t m_frame_number; // What stack frame this RegisterContext is 198 199 std::map<uint32_t, lldb_private::UnwindLLDB::RegisterLocation> m_registers; // where to find reg values for this frame 200 201 lldb_private::UnwindLLDB& m_parent_unwind; // The UnwindLLDB that is creating this RegisterContextLLDB 202 203 //------------------------------------------------------------------ 204 // For RegisterContextLLDB only 205 //------------------------------------------------------------------ 206 207 DISALLOW_COPY_AND_ASSIGN (RegisterContextLLDB); 208 }; 209 210 } // namespace lldb_private 211 212 #endif // lldb_RegisterContextLLDB_h_ 213
