xref: /NextBSD/contrib/llvm/tools/lldb/source/Plugins/ABI/SysV-arm64/ABISysV_arm64.h (revision 84d351007654069f9643c8e4b4802a7f5f08ee42)
1 //===-- ABISysV_arm64.h ---------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef liblldb_ABISysV_arm64_h_
11 #define liblldb_ABISysV_arm64_h_
12 
13 // C Includes
14 // C++ Includes
15 // Other libraries and framework includes
16 // Project includes
17 #include "lldb/lldb-private.h"
18 #include "lldb/Target/ABI.h"
19 
20 class ABISysV_arm64 : public lldb_private::ABI
21 {
22 public:
~ABISysV_arm64()23     ~ABISysV_arm64() { }
24 
25     size_t
26     GetRedZoneSize () const override;
27 
28     bool
29     PrepareTrivialCall (lldb_private::Thread &thread,
30                         lldb::addr_t sp,
31                         lldb::addr_t functionAddress,
32                         lldb::addr_t returnAddress,
33                         llvm::ArrayRef<lldb::addr_t> args) const override;
34 
35     bool
36     GetArgumentValues (lldb_private::Thread &thread,
37                        lldb_private::ValueList &values) const override;
38 
39     lldb_private::Error
40     SetReturnValueObject(lldb::StackFrameSP &frame_sp, lldb::ValueObjectSP &new_value) override;
41 
42 protected:
43     lldb::ValueObjectSP
44     GetReturnValueObjectImpl (lldb_private::Thread &thread,
45                     lldb_private::ClangASTType &ast_type) const override;
46 
47 public:
48     bool
49     CreateFunctionEntryUnwindPlan (lldb_private::UnwindPlan &unwind_plan) override;
50 
51     bool
52     CreateDefaultUnwindPlan (lldb_private::UnwindPlan &unwind_plan) override;
53 
54     bool
55     RegisterIsVolatile (const lldb_private::RegisterInfo *reg_info) override;
56 
57     // The arm64 ABI requires that stack frames be 16 byte aligned.
58     // When there is a trap handler on the stack, e.g. _sigtramp in userland
59     // code, we've seen that the stack pointer is often not aligned properly
60     // before the handler is invoked.  This means that lldb will stop the unwind
61     // early -- before the function which caused the trap.
62     //
63     // To work around this, we relax that alignment to be just word-size (8-bytes).
64     // Whitelisting the trap handlers for user space would be easy (_sigtramp) but
65     // in other environments there can be a large number of different functions
66     // involved in async traps.
67 
68     bool
CallFrameAddressIsValid(lldb::addr_t cfa)69     CallFrameAddressIsValid (lldb::addr_t cfa) override
70     {
71         // Make sure the stack call frame addresses are are 8 byte aligned
72         if (cfa & (8ull - 1ull))
73             return false;   // Not 8 byte aligned
74         if (cfa == 0)
75             return false;   // Zero is not a valid stack address
76         return true;
77     }
78 
79     bool
CodeAddressIsValid(lldb::addr_t pc)80     CodeAddressIsValid (lldb::addr_t pc) override
81     {
82         if (pc & (4ull - 1ull))
83             return false;   // Not 4 byte aligned
84 
85         // Anything else if fair game..
86         return true;
87     }
88 
89     const lldb_private::RegisterInfo *
90     GetRegisterInfoArray (uint32_t &count) override;
91 
92     //------------------------------------------------------------------
93     // Static Functions
94     //------------------------------------------------------------------
95     static void
96     Initialize();
97 
98     static void
99     Terminate();
100 
101     static lldb::ABISP
102     CreateInstance (const lldb_private::ArchSpec &arch);
103 
104     static lldb_private::ConstString
105     GetPluginNameStatic();
106 
107     //------------------------------------------------------------------
108     // PluginInterface protocol
109     //------------------------------------------------------------------
110     lldb_private::ConstString
111     GetPluginName() override;
112 
113     uint32_t
114     GetPluginVersion() override;
115 
116 protected:
117 private:
ABISysV_arm64()118     ABISysV_arm64() :
119         lldb_private::ABI()
120     {
121          // Call CreateInstance instead.
122     }
123 };
124 
125 #endif  // liblldb_ABISysV_arm64_h_
126