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