1 //===-- ABIMacOSX_arm64.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_AARCH64_ABIMACOSX_ARM64_H
10 #define LLDB_SOURCE_PLUGINS_ABI_AARCH64_ABIMACOSX_ARM64_H
11 
12 #include "Plugins/ABI/AArch64/ABIAArch64.h"
13 #include "lldb/Utility/ConstString.h"
14 #include "lldb/lldb-private.h"
15 
16 class ABIMacOSX_arm64 : public ABIAArch64 {
17 public:
18   ~ABIMacOSX_arm64() override = default;
19 
20   size_t GetRedZoneSize() const override;
21 
22   bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp,
23                           lldb::addr_t functionAddress,
24                           lldb::addr_t returnAddress,
25                           llvm::ArrayRef<lldb::addr_t> args) const override;
26 
27   bool GetArgumentValues(lldb_private::Thread &thread,
28                          lldb_private::ValueList &values) const override;
29 
30   bool
31   CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
32 
33   bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
34 
35   bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override;
36 
37   // The arm64 ABI requires that stack frames be 16 byte aligned.
38   // When there is a trap handler on the stack, e.g. _sigtramp in userland
39   // code, we've seen that the stack pointer is often not aligned properly
40   // before the handler is invoked.  This means that lldb will stop the unwind
41   // early -- before the function which caused the trap.
42   //
43   // To work around this, we relax that alignment to be just word-size
44   // (8-bytes).
45   // Allowing the trap handlers for user space would be easy (_sigtramp) but
46   // in other environments there can be a large number of different functions
47   // involved in async traps.
CallFrameAddressIsValid(lldb::addr_t cfa)48   bool CallFrameAddressIsValid(lldb::addr_t cfa) override {
49     // Make sure the stack call frame addresses are are 8 byte aligned
50     if (cfa & (8ull - 1ull))
51       return false; // Not 8 byte aligned
52     if (cfa == 0)
53       return false; // Zero is not a valid stack address
54     return true;
55   }
56 
CodeAddressIsValid(lldb::addr_t pc)57   bool CodeAddressIsValid(lldb::addr_t pc) override {
58     if (pc & (4ull - 1ull))
59       return false; // Not 4 byte aligned
60 
61     // Anything else if fair game..
62     return true;
63   }
64 
65   // Static Functions
66 
67   static void Initialize();
68 
69   static void Terminate();
70 
71   static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);
72 
73   // PluginInterface protocol
74 
75   static lldb_private::ConstString GetPluginNameStatic();
76 
GetPluginName()77   lldb_private::ConstString GetPluginName() override {
78     return GetPluginNameStatic();
79   }
80 
81   uint32_t GetPluginVersion() override;
82 
83   lldb_private::Status
84   SetReturnValueObject(lldb::StackFrameSP &frame_sp,
85                        lldb::ValueObjectSP &new_value) override;
86 
87 protected:
88   lldb::ValueObjectSP
89   GetReturnValueObjectImpl(lldb_private::Thread &thread,
90                            lldb_private::CompilerType &ast_type) const override;
91 
92 private:
93   using ABIAArch64::ABIAArch64; // Call CreateInstance instead.
94 };
95 
96 #endif // LLDB_SOURCE_PLUGINS_ABI_AARCH64_ABIMACOSX_ARM64_H
97