1//===-- ABISysV_x86_64.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_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H
10#define LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H
11
12#include "Plugins/ABI/X86/ABIX86_64.h"
13
14class ABISysV_x86_64 : public ABIX86_64 {
15public:
16  ~ABISysV_x86_64() override = default;
17
18  size_t GetRedZoneSize() const override;
19
20  bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp,
21                          lldb::addr_t functionAddress,
22                          lldb::addr_t returnAddress,
23                          llvm::ArrayRef<lldb::addr_t> args) const override;
24
25  bool GetArgumentValues(lldb_private::Thread &thread,
26                         lldb_private::ValueList &values) const override;
27
28  lldb_private::Status
29  SetReturnValueObject(lldb::StackFrameSP &frame_sp,
30                       lldb::ValueObjectSP &new_value) override;
31
32  lldb::ValueObjectSP
33  GetReturnValueObjectImpl(lldb_private::Thread &thread,
34                           lldb_private::CompilerType &type) const override;
35
36  bool
37  CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
38
39  bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
40
41  bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override;
42
43  // The SysV x86_64 ABI requires that stack frames be 16 byte aligned.
44  // When there is a trap handler on the stack, e.g. _sigtramp in userland
45  // code, we've seen that the stack pointer is often not aligned properly
46  // before the handler is invoked.  This means that lldb will stop the unwind
47  // early -- before the function which caused the trap.
48  //
49  // To work around this, we relax that alignment to be just word-size
50  // (8-bytes).
51  // Allowing the trap handlers for user space would be easy (_sigtramp) but
52  // in other environments there can be a large number of different functions
53  // involved in async traps.
54  bool CallFrameAddressIsValid(lldb::addr_t cfa) override {
55    // Make sure the stack call frame addresses are 8 byte aligned
56    if (cfa & (8ull - 1ull))
57      return false; // Not 8 byte aligned
58    if (cfa == 0)
59      return false; // Zero is not a valid stack address
60    return true;
61  }
62
63  bool CodeAddressIsValid(lldb::addr_t pc) override {
64    // We have a 64 bit address space, so anything is valid as opcodes
65    // aren't fixed width...
66    return true;
67  }
68
69  bool GetPointerReturnRegister(const char *&name) override;
70
71  // Static Functions
72
73  static void Initialize();
74
75  static void Terminate();
76
77  static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);
78
79  static llvm::StringRef GetPluginNameStatic() { return "sysv-x86_64"; }
80
81  // PluginInterface protocol
82  llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
83
84protected:
85  void CreateRegisterMapIfNeeded();
86
87  lldb::ValueObjectSP
88  GetReturnValueObjectSimple(lldb_private::Thread &thread,
89                             lldb_private::CompilerType &ast_type) const;
90
91  bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info);
92  uint32_t GetGenericNum(llvm::StringRef reg) override;
93
94private:
95  using ABIX86_64::ABIX86_64; // Call CreateInstance instead.
96};
97
98#endif // LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H
99