1 //===-- RegisterContextWindows.cpp ------------------------------*- 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 #include "lldb/lldb-private-types.h"
11 #include "lldb/Core/DataBufferHeap.h"
12 #include "lldb/Core/Error.h"
13 #include "lldb/Host/windows/HostThreadWindows.h"
14 #include "lldb/Host/windows/windows.h"
15 
16 #include "ProcessWindowsLog.h"
17 #include "RegisterContextWindows.h"
18 #include "TargetThreadWindows.h"
19 
20 #include "llvm/ADT/STLExtras.h"
21 
22 using namespace lldb;
23 using namespace lldb_private;
24 
25 const DWORD kWinContextFlags = CONTEXT_CONTROL | CONTEXT_INTEGER;
26 
27 //------------------------------------------------------------------
28 // Constructors and Destructors
29 //------------------------------------------------------------------
30 RegisterContextWindows::RegisterContextWindows(Thread &thread, uint32_t concrete_frame_idx)
31     : RegisterContext(thread, concrete_frame_idx)
32     , m_context()
33     , m_context_stale(true)
34 {
35 }
36 
37 RegisterContextWindows::~RegisterContextWindows()
38 {
39 }
40 
41 void
42 RegisterContextWindows::InvalidateAllRegisters()
43 {
44     m_context_stale = true;
45 }
46 
47 bool
48 RegisterContextWindows::ReadAllRegisterValues(lldb::DataBufferSP &data_sp)
49 {
50     if (!CacheAllRegisterValues())
51         return false;
52     if (data_sp->GetByteSize() < sizeof(m_context))
53     {
54         data_sp.reset(new DataBufferHeap(sizeof(CONTEXT), 0));
55     }
56     memcpy(data_sp->GetBytes(), &m_context, sizeof(m_context));
57     return true;
58 }
59 
60 bool
61 RegisterContextWindows::WriteAllRegisterValues(const lldb::DataBufferSP &data_sp)
62 {
63     assert(data_sp->GetByteSize() >= sizeof(m_context));
64     memcpy(&m_context, data_sp->GetBytes(), sizeof(m_context));
65 
66     TargetThreadWindows &wthread = static_cast<TargetThreadWindows &>(m_thread);
67     if (!::SetThreadContext(wthread.GetHostThread().GetNativeThread().GetSystemHandle(), &m_context))
68         return false;
69 
70     return true;
71 }
72 
73 uint32_t
74 RegisterContextWindows::ConvertRegisterKindToRegisterNumber(lldb::RegisterKind kind, uint32_t num)
75 {
76     const uint32_t num_regs = GetRegisterCount();
77 
78     assert(kind < kNumRegisterKinds);
79     for (uint32_t reg_idx = 0; reg_idx < num_regs; ++reg_idx)
80     {
81         const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg_idx);
82 
83         if (reg_info->kinds[kind] == num)
84             return reg_idx;
85     }
86 
87     return LLDB_INVALID_REGNUM;
88 }
89 
90 //------------------------------------------------------------------
91 // Subclasses can these functions if desired
92 //------------------------------------------------------------------
93 uint32_t
94 RegisterContextWindows::NumSupportedHardwareBreakpoints()
95 {
96     // Support for hardware breakpoints not yet implemented.
97     return 0;
98 }
99 
100 uint32_t
101 RegisterContextWindows::SetHardwareBreakpoint(lldb::addr_t addr, size_t size)
102 {
103     return 0;
104 }
105 
106 bool
107 RegisterContextWindows::ClearHardwareBreakpoint(uint32_t hw_idx)
108 {
109     return false;
110 }
111 
112 uint32_t
113 RegisterContextWindows::NumSupportedHardwareWatchpoints()
114 {
115     // Support for hardware watchpoints not yet implemented.
116     return 0;
117 }
118 
119 uint32_t
120 RegisterContextWindows::SetHardwareWatchpoint(lldb::addr_t addr, size_t size, bool read, bool write)
121 {
122     return 0;
123 }
124 
125 bool
126 RegisterContextWindows::ClearHardwareWatchpoint(uint32_t hw_index)
127 {
128     return false;
129 }
130 
131 bool
132 RegisterContextWindows::HardwareSingleStep(bool enable)
133 {
134     return false;
135 }
136 
137 bool
138 RegisterContextWindows::CacheAllRegisterValues()
139 {
140     if (!m_context_stale)
141         return true;
142 
143     TargetThreadWindows &wthread = static_cast<TargetThreadWindows &>(m_thread);
144     memset(&m_context, 0, sizeof(m_context));
145     m_context.ContextFlags = kWinContextFlags;
146     if (!::GetThreadContext(wthread.GetHostThread().GetNativeThread().GetSystemHandle(), &m_context))
147     {
148         WINERR_IFALL(WINDOWS_LOG_REGISTERS, "GetThreadContext failed with error %u while caching register values.",
149                      ::GetLastError());
150         return false;
151     }
152     WINLOG_IFALL(WINDOWS_LOG_REGISTERS, "GetThreadContext successfully updated the register values.", ::GetLastError());
153     m_context_stale = false;
154     return true;
155 }
156