1 //===-- ABI.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_ABI_H 10 #define LLDB_TARGET_ABI_H 11 12 #include "lldb/Core/PluginInterface.h" 13 #include "lldb/Symbol/UnwindPlan.h" 14 #include "lldb/Target/DynamicRegisterInfo.h" 15 #include "lldb/Utility/Status.h" 16 #include "lldb/lldb-private.h" 17 18 #include "llvm/ADT/ArrayRef.h" 19 #include "llvm/MC/MCRegisterInfo.h" 20 21 namespace llvm { 22 class Type; 23 } 24 25 namespace lldb_private { 26 27 class ABI : public PluginInterface { 28 public: 29 struct CallArgument { 30 enum eType { 31 HostPointer = 0, /* pointer to host data */ 32 TargetValue, /* value is on the target or literal */ 33 }; 34 eType type; /* value of eType */ 35 size_t size; /* size in bytes of this argument */ 36 37 lldb::addr_t value; /* literal value */ 38 std::unique_ptr<uint8_t[]> data_up; /* host data pointer */ 39 }; 40 41 ~ABI() override; 42 43 virtual size_t GetRedZoneSize() const = 0; 44 45 virtual bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp, 46 lldb::addr_t functionAddress, 47 lldb::addr_t returnAddress, 48 llvm::ArrayRef<lldb::addr_t> args) const = 0; 49 50 // Prepare trivial call used from ThreadPlanFunctionCallUsingABI 51 // AD: 52 // . Because i don't want to change other ABI's this is not declared pure 53 // virtual. 54 // The dummy implementation will simply fail. Only HexagonABI will 55 // currently 56 // use this method. 57 // . Two PrepareTrivialCall's is not good design so perhaps this should be 58 // combined. 59 // 60 virtual bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp, 61 lldb::addr_t functionAddress, 62 lldb::addr_t returnAddress, 63 llvm::Type &prototype, 64 llvm::ArrayRef<CallArgument> args) const; 65 66 virtual bool GetArgumentValues(Thread &thread, ValueList &values) const = 0; 67 68 lldb::ValueObjectSP GetReturnValueObject(Thread &thread, CompilerType &type, 69 bool persistent = true) const; 70 71 // specialized to work with llvm IR types 72 lldb::ValueObjectSP GetReturnValueObject(Thread &thread, llvm::Type &type, 73 bool persistent = true) const; 74 75 // Set the Return value object in the current frame as though a function with 76 virtual Status SetReturnValueObject(lldb::StackFrameSP &frame_sp, 77 lldb::ValueObjectSP &new_value) = 0; 78 79 protected: 80 // This is the method the ABI will call to actually calculate the return 81 // value. Don't put it in a persistent value object, that will be done by the 82 // ABI::GetReturnValueObject. 83 virtual lldb::ValueObjectSP 84 GetReturnValueObjectImpl(Thread &thread, CompilerType &ast_type) const = 0; 85 86 // specialized to work with llvm IR types 87 virtual lldb::ValueObjectSP 88 GetReturnValueObjectImpl(Thread &thread, llvm::Type &ir_type) const; 89 90 /// Request to get a Process shared pointer. 91 /// 92 /// This ABI object may not have been created with a Process object, 93 /// or the Process object may no longer be alive. Be sure to handle 94 /// the case where the shared pointer returned does not have an 95 /// object inside it. GetProcessSP()96 lldb::ProcessSP GetProcessSP() const { return m_process_wp.lock(); } 97 98 public: 99 virtual bool CreateFunctionEntryUnwindPlan(UnwindPlan &unwind_plan) = 0; 100 101 virtual bool CreateDefaultUnwindPlan(UnwindPlan &unwind_plan) = 0; 102 103 virtual bool RegisterIsVolatile(const RegisterInfo *reg_info) = 0; 104 105 virtual bool 106 GetFallbackRegisterLocation(const RegisterInfo *reg_info, 107 UnwindPlan::Row::RegisterLocation &unwind_regloc); 108 109 // Should take a look at a call frame address (CFA) which is just the stack 110 // pointer value upon entry to a function. ABIs usually impose alignment 111 // restrictions (4, 8 or 16 byte aligned), and zero is usually not allowed. 112 // This function should return true if "cfa" is valid call frame address for 113 // the ABI, and false otherwise. This is used by the generic stack frame 114 // unwinding code to help determine when a stack ends. 115 virtual bool CallFrameAddressIsValid(lldb::addr_t cfa) = 0; 116 117 // Validates a possible PC value and returns true if an opcode can be at 118 // "pc". 119 virtual bool CodeAddressIsValid(lldb::addr_t pc) = 0; 120 121 /// Some targets might use bits in a code address to indicate a mode switch. 122 /// ARM uses bit zero to signify a code address is thumb, so any ARM ABI 123 /// plug-ins would strip those bits. 124 /// @{ 125 virtual lldb::addr_t FixCodeAddress(lldb::addr_t pc); 126 virtual lldb::addr_t FixDataAddress(lldb::addr_t pc); 127 /// @} 128 129 /// Use this method when you do not know, or do not care what kind of address 130 /// you are fixing. On platforms where there would be a difference between the 131 /// two types, it will pick the safest option. 132 /// 133 /// Its purpose is to signal that no specific choice was made and provide an 134 /// alternative to randomly picking FixCode/FixData address. Which could break 135 /// platforms where there is a difference (only Arm Thumb at this time). FixAnyAddress(lldb::addr_t pc)136 virtual lldb::addr_t FixAnyAddress(lldb::addr_t pc) { 137 // On Arm Thumb fixing a code address zeroes the bottom bit, so FixData is 138 // the safe choice. On any other platform (so far) code and data addresses 139 // are fixed in the same way. 140 return FixDataAddress(pc); 141 } 142 GetMCRegisterInfo()143 llvm::MCRegisterInfo &GetMCRegisterInfo() { return *m_mc_register_info_up; } 144 145 virtual void 146 AugmentRegisterInfo(std::vector<DynamicRegisterInfo::Register> ®s) = 0; 147 GetPointerReturnRegister(const char * & name)148 virtual bool GetPointerReturnRegister(const char *&name) { return false; } 149 GetStackFrameSize()150 virtual uint64_t GetStackFrameSize() { return 512 * 1024; } 151 152 static lldb::ABISP FindPlugin(lldb::ProcessSP process_sp, const ArchSpec &arch); 153 154 protected: ABI(lldb::ProcessSP process_sp,std::unique_ptr<llvm::MCRegisterInfo> info_up)155 ABI(lldb::ProcessSP process_sp, std::unique_ptr<llvm::MCRegisterInfo> info_up) 156 : m_process_wp(process_sp), m_mc_register_info_up(std::move(info_up)) { 157 assert(m_mc_register_info_up && "ABI must have MCRegisterInfo"); 158 } 159 160 /// Utility function to construct a MCRegisterInfo using the ArchSpec triple. 161 /// Plugins wishing to customize the construction can construct the 162 /// MCRegisterInfo themselves. 163 static std::unique_ptr<llvm::MCRegisterInfo> 164 MakeMCRegisterInfo(const ArchSpec &arch); 165 166 lldb::ProcessWP m_process_wp; 167 std::unique_ptr<llvm::MCRegisterInfo> m_mc_register_info_up; 168 169 private: 170 ABI(const ABI &) = delete; 171 const ABI &operator=(const ABI &) = delete; 172 }; 173 174 class RegInfoBasedABI : public ABI { 175 public: 176 void AugmentRegisterInfo( 177 std::vector<DynamicRegisterInfo::Register> ®s) override; 178 179 protected: 180 using ABI::ABI; 181 182 bool GetRegisterInfoByName(llvm::StringRef name, RegisterInfo &info); 183 184 virtual const RegisterInfo *GetRegisterInfoArray(uint32_t &count) = 0; 185 }; 186 187 class MCBasedABI : public ABI { 188 public: 189 void AugmentRegisterInfo( 190 std::vector<DynamicRegisterInfo::Register> ®s) override; 191 192 /// If the register name is of the form "<from_prefix>[<number>]" then change 193 /// the name to "<to_prefix>[<number>]". Otherwise, leave the name unchanged. 194 static void MapRegisterName(std::string ®, llvm::StringRef from_prefix, 195 llvm::StringRef to_prefix); 196 197 protected: 198 using ABI::ABI; 199 200 /// Return eh_frame and dwarf numbers for the given register. 201 virtual std::pair<uint32_t, uint32_t> GetEHAndDWARFNums(llvm::StringRef reg); 202 203 /// Return the generic number of the given register. 204 virtual uint32_t GetGenericNum(llvm::StringRef reg) = 0; 205 206 /// For the given (capitalized) lldb register name, return the name of this 207 /// register in the MCRegisterInfo struct. GetMCName(std::string reg)208 virtual std::string GetMCName(std::string reg) { return reg; } 209 }; 210 211 } // namespace lldb_private 212 213 #endif // LLDB_TARGET_ABI_H 214