summaryrefslogtreecommitdiffstats
path: root/lldb/source/Plugins/ABI/SysV-i386/ABISysV_i386.h
blob: 2d0f097c328e62eac27dd986b4726311e5fd353a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
//===------------------- ABISysV_i386.h -------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef liblldb_ABISysV_i386_h_
#define liblldb_ABISysV_i386_h_

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/lldb-private.h"
#include "lldb/Target/ABI.h"

class ABISysV_i386 :
    public lldb_private::ABI
{
public:
    ~ABISysV_i386() override = default;

    size_t
    GetRedZoneSize () const override
    {
        return 0; // There is no red zone for i386 Architecture
    }

    bool
    PrepareTrivialCall (lldb_private::Thread &thread,
                        lldb::addr_t sp,
                        lldb::addr_t functionAddress,
                        lldb::addr_t returnAddress,
                        llvm::ArrayRef<lldb::addr_t> args) const override;

    bool
    GetArgumentValues (lldb_private::Thread &thread,
                       lldb_private::ValueList &values) const override;

    lldb_private::Error
    SetReturnValueObject(lldb::StackFrameSP &frame_sp, lldb::ValueObjectSP &new_value) override;

    lldb::ValueObjectSP
    GetReturnValueObjectImpl (lldb_private::Thread &thread,
                          lldb_private::CompilerType &type) const override;

    bool
    CreateFunctionEntryUnwindPlan (lldb_private::UnwindPlan &unwind_plan) override;

    bool
    CreateDefaultUnwindPlan (lldb_private::UnwindPlan &unwind_plan) override;

    bool
    RegisterIsVolatile (const lldb_private::RegisterInfo *reg_info) override
    {
        return !RegisterIsCalleeSaved (reg_info);
    }

    // The SysV i386 ABI requires that stack frames be 16 byte aligned.
    // When there is a trap handler on the stack, e.g. _sigtramp in userland
    // code, we've seen that the stack pointer is often not aligned properly
    // before the handler is invoked.  This means that lldb will stop the unwind
    // early -- before the function which caused the trap.
    //
    // To work around this, we relax that alignment to be just word-size (4-bytes).
    // Whitelisting the trap handlers for user space would be easy (_sigtramp) but
    // in other environments there can be a large number of different functions
    // involved in async traps.

    // ToDo: When __m256 arguments are passed then stack frames should be
    // 32 byte aligned. Decide what to do for 32 byte alignment checking
    bool
    CallFrameAddressIsValid (lldb::addr_t cfa) override
    {
        // Make sure the stack call frame addresses are 4 byte aligned
        if (cfa & (4ull - 1ull))
            return false;   // Not 4 byte aligned
        if (cfa == 0)
            return false;   // Zero is not a valid stack address
        return true;
    }

    bool
    CodeAddressIsValid (lldb::addr_t pc) override
    {
        // Check whether the address is a valid 32 bit address
        return (pc <= UINT32_MAX);
    }

    const lldb_private::RegisterInfo *
    GetRegisterInfoArray (uint32_t &count) override;

    //------------------------------------------------------------------
    // Static Functions
    //------------------------------------------------------------------

    static void
    Initialize();

    static void
    Terminate();

    static lldb::ABISP
    CreateInstance (const lldb_private::ArchSpec &arch);

    //------------------------------------------------------------------
    // PluginInterface protocol
    //------------------------------------------------------------------

    static lldb_private::ConstString
    GetPluginNameStatic();

    lldb_private::ConstString
    GetPluginName() override;

    uint32_t
    GetPluginVersion() override
    {
        return 1;
    }

protected:
    lldb::ValueObjectSP
    GetReturnValueObjectSimple(lldb_private::Thread &thread,
                               lldb_private::CompilerType &ast_type) const;

    bool
    RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info);

private:
    ABISysV_i386() : 
        lldb_private::ABI() 
    {
         // Call CreateInstance instead.
    }
};

#endif // liblldb_ABISysV_i386_h_
OpenPOWER on IntegriCloud