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
20namespace llvm {
21class Type;
22}
23
24namespace lldb_private {
25
26class ABI : public PluginInterface {
27public:
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
78protected:
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
97public:
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 /// Some targets might use bits in a code address to indicate a mode switch.
121 /// ARM uses bit zero to signify a code address is thumb, so any ARM ABI
122 /// plug-ins would strip those bits.
123 /// @{
124 virtual lldb::addr_t FixCodeAddress(lldb::addr_t pc) { return pc; }
125 virtual lldb::addr_t FixDataAddress(lldb::addr_t pc) { return pc; }
126 /// @}
127
128 llvm::MCRegisterInfo &GetMCRegisterInfo() { return *m_mc_register_info_up; }
129
130 virtual void AugmentRegisterInfo(RegisterInfo &info) = 0;
131
132 virtual bool GetPointerReturnRegister(const char *&name) { return false; }
133
134 static lldb::ABISP FindPlugin(lldb::ProcessSP process_sp, const ArchSpec &arch);
135
136protected:
137 ABI(lldb::ProcessSP process_sp, std::unique_ptr<llvm::MCRegisterInfo> info_up)
138 : m_process_wp(process_sp), m_mc_register_info_up(std::move(info_up)) {
139 assert(m_mc_register_info_up && "ABI must have MCRegisterInfo");
140 }
141
142 /// Utility function to construct a MCRegisterInfo using the ArchSpec triple.
143 /// Plugins wishing to customize the construction can construct the
144 /// MCRegisterInfo themselves.
145 static std::unique_ptr<llvm::MCRegisterInfo>
146 MakeMCRegisterInfo(const ArchSpec &arch);
147
148 lldb::ProcessWP m_process_wp;
149 std::unique_ptr<llvm::MCRegisterInfo> m_mc_register_info_up;
150
151 virtual lldb::addr_t FixCodeAddress(lldb::addr_t pc, lldb::addr_t mask) {
152 return pc;
153 }
154
155private:
156 ABI(const ABI &) = delete;
157 const ABI &operator=(const ABI &) = delete;
158};
159
160class RegInfoBasedABI : public ABI {
161public:
162 void AugmentRegisterInfo(RegisterInfo &info) override;
163
164protected:
165 using ABI::ABI;
166
167 bool GetRegisterInfoByName(llvm::StringRef name, RegisterInfo &info);
168
169 virtual const RegisterInfo *GetRegisterInfoArray(uint32_t &count) = 0;
170};
171
172class MCBasedABI : public ABI {
173public:
174 void AugmentRegisterInfo(RegisterInfo &info) override;
175
176 /// If the register name is of the form "<from_prefix>[<number>]" then change
177 /// the name to "<to_prefix>[<number>]". Otherwise, leave the name unchanged.
178 static void MapRegisterName(std::string &reg, llvm::StringRef from_prefix,
179 llvm::StringRef to_prefix);
180protected:
181 using ABI::ABI;
182
183 /// Return eh_frame and dwarf numbers for the given register.
184 virtual std::pair<uint32_t, uint32_t> GetEHAndDWARFNums(llvm::StringRef reg);
185
186 /// Return the generic number of the given register.
187 virtual uint32_t GetGenericNum(llvm::StringRef reg) = 0;
188
189 /// For the given (capitalized) lldb register name, return the name of this
190 /// register in the MCRegisterInfo struct.
191 virtual std::string GetMCName(std::string reg) { return reg; }
192};
193
194} // namespace lldb_private
195
196#endif // LLDB_TARGET_ABI_H
197