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 liblldb_ABI_h_
10#define liblldb_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  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);
130
131  virtual bool GetPointerReturnRegister(const char *&name) { return false; }
132
133  static lldb::ABISP FindPlugin(lldb::ProcessSP process_sp, const ArchSpec &arch);
134
135protected:
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  bool GetRegisterInfoByName(ConstString name, RegisterInfo &info);
142
143  virtual const RegisterInfo *GetRegisterInfoArray(uint32_t &count) = 0;
144
145  /// Utility function to construct a MCRegisterInfo using the ArchSpec triple.
146  /// Plugins wishing to customize the construction can construct the
147  /// MCRegisterInfo themselves.
148  static std::unique_ptr<llvm::MCRegisterInfo>
149  MakeMCRegisterInfo(const ArchSpec &arch);
150
151  lldb::ProcessWP m_process_wp;
152  std::unique_ptr<llvm::MCRegisterInfo> m_mc_register_info_up;
153
154private:
155  DISALLOW_COPY_AND_ASSIGN(ABI);
156};
157
158} // namespace lldb_private
159
160#endif // liblldb_ABI_h_
161