1 //===-- UnwindLLDB.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_UnwindLLDB_h_ 11 #define lldb_UnwindLLDB_h_ 12 13 // C Includes 14 // C++ Includes 15 #include <vector> 16 17 // Other libraries and framework includes 18 // Project includes 19 #include "lldb/Symbol/FuncUnwinders.h" 20 #include "lldb/Symbol/UnwindPlan.h" 21 #include "lldb/Target/RegisterContext.h" 22 #include "lldb/Target/Unwind.h" 23 #include "lldb/Utility/ConstString.h" 24 #include "lldb/lldb-public.h" 25 26 namespace lldb_private { 27 28 class RegisterContextLLDB; 29 30 class UnwindLLDB : public lldb_private::Unwind { 31 public: 32 UnwindLLDB(lldb_private::Thread &thread); 33 34 ~UnwindLLDB() override = default; 35 36 enum RegisterSearchResult { 37 eRegisterFound = 0, 38 eRegisterNotFound, 39 eRegisterIsVolatile 40 }; 41 42 protected: 43 friend class lldb_private::RegisterContextLLDB; 44 45 struct RegisterLocation { 46 enum RegisterLocationTypes { 47 eRegisterNotSaved = 0, // register was not preserved by callee. If 48 // volatile reg, is unavailable 49 eRegisterSavedAtMemoryLocation, // register is saved at a specific word of 50 // target mem (target_memory_location) 51 eRegisterInRegister, // register is available in a (possible other) 52 // register (register_number) 53 eRegisterSavedAtHostMemoryLocation, // register is saved at a word in 54 // lldb's address space 55 eRegisterValueInferred, // register val was computed (and is in 56 // inferred_value) 57 eRegisterInLiveRegisterContext // register value is in a live (stack frame 58 // #0) register 59 }; 60 int type; 61 union { 62 lldb::addr_t target_memory_location; 63 uint32_t 64 register_number; // in eRegisterKindLLDB register numbering system 65 void *host_memory_location; 66 uint64_t inferred_value; // eRegisterValueInferred - e.g. stack pointer == 67 // cfa + offset 68 } location; 69 }; 70 71 void DoClear() override { 72 m_frames.clear(); 73 m_candidate_frame.reset(); 74 m_unwind_complete = false; 75 } 76 77 uint32_t DoGetFrameCount() override; 78 79 bool DoGetFrameInfoAtIndex(uint32_t frame_idx, lldb::addr_t &cfa, 80 lldb::addr_t &start_pc) override; 81 82 lldb::RegisterContextSP 83 DoCreateRegisterContextForFrame(lldb_private::StackFrame *frame) override; 84 85 typedef std::shared_ptr<RegisterContextLLDB> RegisterContextLLDBSP; 86 87 // Needed to retrieve the "next" frame (e.g. frame 2 needs to retrieve frame 88 // 1's RegisterContextLLDB) 89 // The RegisterContext for frame_num must already exist or this returns an 90 // empty shared pointer. 91 RegisterContextLLDBSP GetRegisterContextForFrameNum(uint32_t frame_num); 92 93 // Iterate over the RegisterContextLLDB's in our m_frames vector, look for the 94 // first one that 95 // has a saved location for this reg. 96 bool SearchForSavedLocationForRegister( 97 uint32_t lldb_regnum, lldb_private::UnwindLLDB::RegisterLocation ®loc, 98 uint32_t starting_frame_num, bool pc_register); 99 100 //------------------------------------------------------------------ 101 /// Provide the list of user-specified trap handler functions 102 /// 103 /// The Platform is one source of trap handler function names; that 104 /// may be augmented via a setting. The setting needs to be converted 105 /// into an array of ConstStrings before it can be used - we only want 106 /// to do that once per thread so it's here in the UnwindLLDB object. 107 /// 108 /// @return 109 /// Vector of ConstStrings of trap handler function names. May be 110 /// empty. 111 //------------------------------------------------------------------ 112 const std::vector<ConstString> &GetUserSpecifiedTrapHandlerFunctionNames() { 113 return m_user_supplied_trap_handler_functions; 114 } 115 116 private: 117 struct Cursor { 118 lldb::addr_t start_pc; // The start address of the function/symbol for this 119 // frame - current pc if unknown 120 lldb::addr_t cfa; // The canonical frame address for this stack frame 121 lldb_private::SymbolContext sctx; // A symbol context we'll contribute to & 122 // provide to the StackFrame creation 123 RegisterContextLLDBSP 124 reg_ctx_lldb_sp; // These are all RegisterContextLLDB's 125 126 Cursor() 127 : start_pc(LLDB_INVALID_ADDRESS), cfa(LLDB_INVALID_ADDRESS), sctx(), 128 reg_ctx_lldb_sp() {} 129 130 private: 131 DISALLOW_COPY_AND_ASSIGN(Cursor); 132 }; 133 134 typedef std::shared_ptr<Cursor> CursorSP; 135 std::vector<CursorSP> m_frames; 136 CursorSP m_candidate_frame; 137 bool m_unwind_complete; // If this is true, we've enumerated all the frames in 138 // the stack, and m_frames.size() is the 139 // number of frames, etc. Otherwise we've only gone as far as directly asked, 140 // and m_frames.size() 141 // is how far we've currently gone. 142 143 std::vector<ConstString> m_user_supplied_trap_handler_functions; 144 145 //----------------------------------------------------------------- 146 // Check if Full UnwindPlan of First frame is valid or not. 147 // If not then try Fallback UnwindPlan of the frame. If Fallback 148 // UnwindPlan succeeds then update the Full UnwindPlan with the 149 // Fallback UnwindPlan. 150 //----------------------------------------------------------------- 151 void UpdateUnwindPlanForFirstFrameIfInvalid(ABI *abi); 152 153 CursorSP GetOneMoreFrame(ABI *abi); 154 155 bool AddOneMoreFrame(ABI *abi); 156 157 bool AddFirstFrame(); 158 159 //------------------------------------------------------------------ 160 // For UnwindLLDB only 161 //------------------------------------------------------------------ 162 DISALLOW_COPY_AND_ASSIGN(UnwindLLDB); 163 }; 164 165 } // namespace lldb_private 166 167 #endif // lldb_UnwindLLDB_h_ 168