1 //===-- RegisterContext.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 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 // Project includes
14 #include "lldb/Target/RegisterContext.h"
15 #include "lldb/Core/DataExtractor.h"
16 #include "lldb/Core/RegisterValue.h"
17 #include "lldb/Core/Scalar.h"
18 #include "lldb/Host/Endian.h"
19 #include "lldb/Target/ExecutionContext.h"
20 #include "lldb/Target/StackFrame.h"
21 #include "lldb/Target/Process.h"
22 #include "lldb/Target/Thread.h"
23 
24 using namespace lldb;
25 using namespace lldb_private;
26 
27 RegisterContext::RegisterContext (Thread &thread, uint32_t concrete_frame_idx) :
28     m_thread (thread),
29     m_concrete_frame_idx (concrete_frame_idx),
30     m_stop_id (thread.GetProcess()->GetStopID())
31 {
32 }
33 
34 //----------------------------------------------------------------------
35 // Destructor
36 //----------------------------------------------------------------------
37 RegisterContext::~RegisterContext()
38 {
39 }
40 
41 void
42 RegisterContext::InvalidateIfNeeded (bool force)
43 {
44     ProcessSP process_sp (m_thread.GetProcess());
45     bool invalidate = force;
46     uint32_t process_stop_id = UINT32_MAX;
47 
48     if (process_sp)
49         process_stop_id = process_sp->GetStopID();
50     else
51         invalidate = true;
52 
53     if (!invalidate)
54         invalidate = process_stop_id != GetStopID();
55 
56     if (invalidate)
57     {
58         InvalidateAllRegisters ();
59         SetStopID (process_stop_id);
60     }
61 }
62 
63 
64 const RegisterInfo *
65 RegisterContext::GetRegisterInfoByName (const char *reg_name, uint32_t start_idx)
66 {
67     if (reg_name && reg_name[0])
68     {
69         const uint32_t num_registers = GetRegisterCount();
70         for (uint32_t reg = start_idx; reg < num_registers; ++reg)
71         {
72             const RegisterInfo * reg_info = GetRegisterInfoAtIndex(reg);
73 
74             if ((reg_info->name != NULL && ::strcasecmp (reg_info->name, reg_name) == 0) ||
75                 (reg_info->alt_name != NULL && ::strcasecmp (reg_info->alt_name, reg_name) == 0))
76             {
77                 return reg_info;
78             }
79         }
80     }
81     return NULL;
82 }
83 
84 const char *
85 RegisterContext::GetRegisterName (uint32_t reg)
86 {
87     const RegisterInfo * reg_info = GetRegisterInfoAtIndex(reg);
88     if (reg_info)
89         return reg_info->name;
90     return NULL;
91 }
92 
93 uint64_t
94 RegisterContext::GetPC(uint64_t fail_value)
95 {
96     uint32_t reg = ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
97     return ReadRegisterAsUnsigned (reg, fail_value);
98 }
99 
100 bool
101 RegisterContext::SetPC(uint64_t pc)
102 {
103     uint32_t reg = ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
104     bool success = WriteRegisterFromUnsigned (reg, pc);
105     if (success)
106     {
107         StackFrameSP frame_sp(m_thread.GetFrameWithConcreteFrameIndex (m_concrete_frame_idx));
108         if (frame_sp)
109             frame_sp->ChangePC(pc);
110         else
111             m_thread.ClearStackFrames ();
112     }
113     return success;
114 }
115 
116 uint64_t
117 RegisterContext::GetSP(uint64_t fail_value)
118 {
119     uint32_t reg = ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
120     return ReadRegisterAsUnsigned (reg, fail_value);
121 }
122 
123 bool
124 RegisterContext::SetSP(uint64_t sp)
125 {
126     uint32_t reg = ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
127     return WriteRegisterFromUnsigned (reg, sp);
128 }
129 
130 uint64_t
131 RegisterContext::GetFP(uint64_t fail_value)
132 {
133     uint32_t reg = ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FP);
134     return ReadRegisterAsUnsigned (reg, fail_value);
135 }
136 
137 bool
138 RegisterContext::SetFP(uint64_t fp)
139 {
140     uint32_t reg = ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FP);
141     return WriteRegisterFromUnsigned (reg, fp);
142 }
143 
144 uint64_t
145 RegisterContext::GetReturnAddress (uint64_t fail_value)
146 {
147     uint32_t reg = ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA);
148     return ReadRegisterAsUnsigned (reg, fail_value);
149 }
150 
151 uint64_t
152 RegisterContext::GetFlags (uint64_t fail_value)
153 {
154     uint32_t reg = ConvertRegisterKindToRegisterNumber (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FLAGS);
155     return ReadRegisterAsUnsigned (reg, fail_value);
156 }
157 
158 
159 uint64_t
160 RegisterContext::ReadRegisterAsUnsigned (uint32_t reg, uint64_t fail_value)
161 {
162     if (reg != LLDB_INVALID_REGNUM)
163         return ReadRegisterAsUnsigned (GetRegisterInfoAtIndex (reg), fail_value);
164     return fail_value;
165 }
166 
167 uint64_t
168 RegisterContext::ReadRegisterAsUnsigned (const RegisterInfo *reg_info, uint64_t fail_value)
169 {
170     if (reg_info)
171     {
172         RegisterValue value;
173         if (ReadRegister (reg_info, value))
174             return value.GetAsUInt64();
175     }
176     return fail_value;
177 }
178 
179 bool
180 RegisterContext::WriteRegisterFromUnsigned (uint32_t reg, uint64_t uval)
181 {
182     if (reg == LLDB_INVALID_REGNUM)
183         return false;
184     return WriteRegisterFromUnsigned (GetRegisterInfoAtIndex (reg), uval);
185 }
186 
187 bool
188 RegisterContext::WriteRegisterFromUnsigned (const RegisterInfo *reg_info, uint64_t uval)
189 {
190     if (reg_info)
191     {
192         RegisterValue value;
193         if (value.SetUInt(uval, reg_info->byte_size))
194             return WriteRegister (reg_info, value);
195     }
196     return false;
197 }
198 
199 lldb::tid_t
200 RegisterContext::GetThreadID() const
201 {
202     return m_thread.GetID();
203 }
204 
205 uint32_t
206 RegisterContext::NumSupportedHardwareBreakpoints ()
207 {
208     return 0;
209 }
210 
211 uint32_t
212 RegisterContext::SetHardwareBreakpoint (lldb::addr_t addr, size_t size)
213 {
214     return LLDB_INVALID_INDEX32;
215 }
216 
217 bool
218 RegisterContext::ClearHardwareBreakpoint (uint32_t hw_idx)
219 {
220     return false;
221 }
222 
223 
224 uint32_t
225 RegisterContext::NumSupportedHardwareWatchpoints ()
226 {
227     return 0;
228 }
229 
230 uint32_t
231 RegisterContext::SetHardwareWatchpoint (lldb::addr_t addr, size_t size, bool read, bool write)
232 {
233     return LLDB_INVALID_INDEX32;
234 }
235 
236 bool
237 RegisterContext::ClearHardwareWatchpoint (uint32_t hw_index)
238 {
239     return false;
240 }
241 
242 bool
243 RegisterContext::HardwareSingleStep (bool enable)
244 {
245     return false;
246 }
247 
248 Error
249 RegisterContext::ReadRegisterValueFromMemory (const RegisterInfo *reg_info,
250                                               lldb::addr_t src_addr,
251                                               uint32_t src_len,
252                                               RegisterValue &reg_value)
253 {
254     Error error;
255     if (reg_info == NULL)
256     {
257         error.SetErrorString ("invalid register info argument.");
258         return error;
259     }
260 
261 
262     // Moving from addr into a register
263     //
264     // Case 1: src_len == dst_len
265     //
266     //   |AABBCCDD| Address contents
267     //   |AABBCCDD| Register contents
268     //
269     // Case 2: src_len > dst_len
270     //
271     //   Error!  (The register should always be big enough to hold the data)
272     //
273     // Case 3: src_len < dst_len
274     //
275     //   |AABB| Address contents
276     //   |AABB0000| Register contents [on little-endian hardware]
277     //   |0000AABB| Register contents [on big-endian hardware]
278     if (src_len > RegisterValue::kMaxRegisterByteSize)
279     {
280         error.SetErrorString ("register too small to receive memory data");
281         return error;
282     }
283 
284     const uint32_t dst_len = reg_info->byte_size;
285 
286     if (src_len > dst_len)
287     {
288         error.SetErrorStringWithFormat("%u bytes is too big to store in register %s (%u bytes)", src_len, reg_info->name, dst_len);
289         return error;
290     }
291 
292     ProcessSP process_sp (m_thread.GetProcess());
293     if (process_sp)
294     {
295         uint8_t src[RegisterValue::kMaxRegisterByteSize];
296 
297         // Read the memory
298         const uint32_t bytes_read = process_sp->ReadMemory (src_addr, src, src_len, error);
299 
300         // Make sure the memory read succeeded...
301         if (bytes_read != src_len)
302         {
303             if (error.Success())
304             {
305                 // This might happen if we read _some_ bytes but not all
306                 error.SetErrorStringWithFormat("read %u of %u bytes", bytes_read, src_len);
307             }
308             return error;
309         }
310 
311         // We now have a memory buffer that contains the part or all of the register
312         // value. Set the register value using this memory data.
313         // TODO: we might need to add a parameter to this function in case the byte
314         // order of the memory data doesn't match the process. For now we are assuming
315         // they are the same.
316         reg_value.SetFromMemoryData (reg_info,
317                                      src,
318                                      src_len,
319                                      process_sp->GetByteOrder(),
320                                      error);
321     }
322     else
323         error.SetErrorString("invalid process");
324 
325     return error;
326 }
327 
328 Error
329 RegisterContext::WriteRegisterValueToMemory (const RegisterInfo *reg_info,
330                                              lldb::addr_t dst_addr,
331                                              uint32_t dst_len,
332                                              const RegisterValue &reg_value)
333 {
334 
335     uint8_t dst[RegisterValue::kMaxRegisterByteSize];
336 
337     Error error;
338 
339     ProcessSP process_sp (m_thread.GetProcess());
340     if (process_sp)
341     {
342 
343         // TODO: we might need to add a parameter to this function in case the byte
344         // order of the memory data doesn't match the process. For now we are assuming
345         // they are the same.
346 
347         const uint32_t bytes_copied = reg_value.GetAsMemoryData (reg_info,
348                                                                  dst,
349                                                                  dst_len,
350                                                                  process_sp->GetByteOrder(),
351                                                                  error);
352 
353         if (error.Success())
354         {
355             if (bytes_copied == 0)
356             {
357                 error.SetErrorString("byte copy failed.");
358             }
359             else
360             {
361                 const uint32_t bytes_written = process_sp->WriteMemory (dst_addr, dst, bytes_copied, error);
362                 if (bytes_written != bytes_copied)
363                 {
364                     if (error.Success())
365                     {
366                         // This might happen if we read _some_ bytes but not all
367                         error.SetErrorStringWithFormat("only wrote %u of %u bytes", bytes_written, bytes_copied);
368                     }
369                 }
370             }
371         }
372     }
373     else
374         error.SetErrorString("invalid process");
375 
376     return error;
377 
378 }
379 
380 TargetSP
381 RegisterContext::CalculateTarget ()
382 {
383     return m_thread.CalculateTarget();
384 }
385 
386 
387 ProcessSP
388 RegisterContext::CalculateProcess ()
389 {
390     return m_thread.CalculateProcess ();
391 }
392 
393 ThreadSP
394 RegisterContext::CalculateThread ()
395 {
396     return m_thread.shared_from_this();
397 }
398 
399 StackFrameSP
400 RegisterContext::CalculateStackFrame ()
401 {
402     // Register contexts might belong to many frames if we have inlined
403     // functions inside a frame since all inlined functions share the
404     // same registers, so we can't definitively say which frame we come from...
405     return StackFrameSP();
406 }
407 
408 void
409 RegisterContext::CalculateExecutionContext (ExecutionContext &exe_ctx)
410 {
411     m_thread.CalculateExecutionContext (exe_ctx);
412 }
413 
414 
415 bool
416 RegisterContext::ConvertBetweenRegisterKinds (int source_rk, uint32_t source_regnum, int target_rk, uint32_t& target_regnum)
417 {
418     const uint32_t num_registers = GetRegisterCount();
419     for (uint32_t reg = 0; reg < num_registers; ++reg)
420     {
421         const RegisterInfo * reg_info = GetRegisterInfoAtIndex (reg);
422 
423         if (reg_info->kinds[source_rk] == source_regnum)
424         {
425             target_regnum = reg_info->kinds[target_rk];
426             if (target_regnum == LLDB_INVALID_REGNUM)
427             {
428                 return false;
429             }
430             else
431             {
432                 return true;
433             }
434         }
435     }
436     return false;
437 }
438 
439 //bool
440 //RegisterContext::ReadRegisterValue (uint32_t reg, Scalar &value)
441 //{
442 //    DataExtractor data;
443 //    if (!ReadRegisterBytes (reg, data))
444 //        return false;
445 //
446 //    const RegisterInfo *reg_info = GetRegisterInfoAtIndex (reg);
447 //    uint32_t offset = 0;
448 //    switch (reg_info->encoding)
449 //    {
450 //    case eEncodingInvalid:
451 //    case eEncodingVector:
452 //        break;
453 //
454 //    case eEncodingUint:
455 //        switch (reg_info->byte_size)
456 //        {
457 //        case 1:
458 //            {
459 //                value = data.GetU8 (&offset);
460 //                return true;
461 //            }
462 //        case 2:
463 //            {
464 //                value = data.GetU16 (&offset);
465 //                return true;
466 //            }
467 //        case 4:
468 //            {
469 //                value = data.GetU32 (&offset);
470 //                return true;
471 //            }
472 //        case 8:
473 //            {
474 //                value = data.GetU64 (&offset);
475 //                return true;
476 //            }
477 //        }
478 //        break;
479 //    case eEncodingSint:
480 //        switch (reg_info->byte_size)
481 //        {
482 //        case 1:
483 //            {
484 //                int8_t v;
485 //                if (data.ExtractBytes (0, sizeof (int8_t), lldb::endian::InlHostByteOrder(), &v) != sizeof (int8_t))
486 //                    return false;
487 //                value = v;
488 //                return true;
489 //            }
490 //        case 2:
491 //            {
492 //                int16_t v;
493 //                if (data.ExtractBytes (0, sizeof (int16_t), lldb::endian::InlHostByteOrder(), &v) != sizeof (int16_t))
494 //                    return false;
495 //                value = v;
496 //                return true;
497 //            }
498 //        case 4:
499 //            {
500 //                int32_t v;
501 //                if (data.ExtractBytes (0, sizeof (int32_t), lldb::endian::InlHostByteOrder(), &v) != sizeof (int32_t))
502 //                    return false;
503 //                value = v;
504 //                return true;
505 //            }
506 //        case 8:
507 //            {
508 //                int64_t v;
509 //                if (data.ExtractBytes (0, sizeof (int64_t), lldb::endian::InlHostByteOrder(), &v) != sizeof (int64_t))
510 //                    return false;
511 //                value = v;
512 //                return true;
513 //            }
514 //        }
515 //        break;
516 //    case eEncodingIEEE754:
517 //        switch (reg_info->byte_size)
518 //        {
519 //        case sizeof (float):
520 //            {
521 //                float v;
522 //                if (data.ExtractBytes (0, sizeof (float), lldb::endian::InlHostByteOrder(), &v) != sizeof (float))
523 //                    return false;
524 //                value = v;
525 //                return true;
526 //            }
527 //        case sizeof (double):
528 //            {
529 //                double v;
530 //                if (data.ExtractBytes (0, sizeof (double), lldb::endian::InlHostByteOrder(), &v) != sizeof (double))
531 //                    return false;
532 //                value = v;
533 //                return true;
534 //            }
535 //        case sizeof (long double):
536 //            {
537 //                double v;
538 //                if (data.ExtractBytes (0, sizeof (long double), lldb::endian::InlHostByteOrder(), &v) != sizeof (long double))
539 //                    return false;
540 //                value = v;
541 //                return true;
542 //            }
543 //        }
544 //        break;
545 //    }
546 //    return false;
547 //}
548 //
549 //bool
550 //RegisterContext::WriteRegisterValue (uint32_t reg, const Scalar &value)
551 //{
552 //    DataExtractor data;
553 //    if (!value.IsValid())
554 //        return false;
555 //    if (!value.GetData (data))
556 //        return false;
557 //
558 //    return WriteRegisterBytes (reg, data);
559 //}
560