1 //===-- ABISysV_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_ABISYSV_ARM64_H
10 #define LLDB_SOURCE_PLUGINS_ABI_AARCH64_ABISYSV_ARM64_H
11 
12 #include "Plugins/ABI/AArch64/ABIAArch64.h"
13 #include "lldb/lldb-private.h"
14 
15 class ABISysV_arm64 : public ABIAArch64 {
16 public:
17   ~ABISysV_arm64() override = default;
18 
19   size_t GetRedZoneSize() const override;
20 
21   bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp,
22                           lldb::addr_t functionAddress,
23                           lldb::addr_t returnAddress,
24                           llvm::ArrayRef<lldb::addr_t> args) const override;
25 
26   bool GetArgumentValues(lldb_private::Thread &thread,
27                          lldb_private::ValueList &values) const override;
28 
29   lldb_private::Status
30   SetReturnValueObject(lldb::StackFrameSP &frame_sp,
31                        lldb::ValueObjectSP &new_value) override;
32 
33   bool
34   CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
35 
36   bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
37 
38   bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override;
39 
40   // The arm64 ABI requires that stack frames be 16 byte aligned.
41   // When there is a trap handler on the stack, e.g. _sigtramp in userland
42   // code, we've seen that the stack pointer is often not aligned properly
43   // before the handler is invoked.  This means that lldb will stop the unwind
44   // early -- before the function which caused the trap.
45   //
46   // To work around this, we relax that alignment to be just word-size
47   // (8-bytes).
48   // Allowing the trap handlers for user space would be easy (_sigtramp) but
49   // in other environments there can be a large number of different functions
50   // involved in async traps.
CallFrameAddressIsValid(lldb::addr_t cfa)51   bool CallFrameAddressIsValid(lldb::addr_t cfa) override {
52     // Make sure the stack call frame addresses are are 8 byte aligned
53     if (cfa & (8ull - 1ull))
54       return false; // Not 8 byte aligned
55     if (cfa == 0)
56       return false; // Zero is not a valid stack address
57     return true;
58   }
59 
CodeAddressIsValid(lldb::addr_t pc)60   bool CodeAddressIsValid(lldb::addr_t pc) override {
61     if (pc & (4ull - 1ull))
62       return false; // Not 4 byte aligned
63 
64     // Anything else if fair game..
65     return true;
66   }
67 
68   bool GetPointerReturnRegister(const char *&name) override;
69 
70   // Static Functions
71 
72   static void Initialize();
73 
74   static void Terminate();
75 
76   static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);
77 
78   static lldb_private::ConstString GetPluginNameStatic();
79 
80   // PluginInterface protocol
81 
82   lldb_private::ConstString GetPluginName() override;
83 
84   uint32_t GetPluginVersion() override;
85 
86 protected:
87   lldb::ValueObjectSP
88   GetReturnValueObjectImpl(lldb_private::Thread &thread,
89                            lldb_private::CompilerType &ast_type) const override;
90 
91 private:
92   using ABIAArch64::ABIAArch64; // Call CreateInstance instead.
93 };
94 
95 #endif // LLDB_SOURCE_PLUGINS_ABI_AARCH64_ABISYSV_ARM64_H
96