1 //===-- DWARFExpression.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/Expression/DWARFExpression.h"
11 
12 // C Includes
13 #include <inttypes.h>
14 
15 // C++ Includes
16 #include <vector>
17 
18 #include "lldb/Core/DataEncoder.h"
19 #include "lldb/Core/dwarf.h"
20 #include "lldb/Core/Log.h"
21 #include "lldb/Core/RegisterValue.h"
22 #include "lldb/Core/StreamString.h"
23 #include "lldb/Core/Scalar.h"
24 #include "lldb/Core/Value.h"
25 #include "lldb/Core/VMRange.h"
26 
27 #include "lldb/Expression/ClangExpressionDeclMap.h"
28 #include "Plugins/ExpressionParser/Clang/ClangExpressionVariable.h"
29 
30 #include "lldb/Host/Endian.h"
31 #include "lldb/Host/Host.h"
32 
33 #include "lldb/Target/ABI.h"
34 #include "lldb/Target/ExecutionContext.h"
35 #include "lldb/Target/Process.h"
36 #include "lldb/Target/RegisterContext.h"
37 #include "lldb/Target/StackFrame.h"
38 #include "lldb/Target/StackID.h"
39 #include "lldb/Target/Thread.h"
40 
41 #include "Plugins/SymbolFile/DWARF/DWARFCompileUnit.h"
42 
43 using namespace lldb;
44 using namespace lldb_private;
45 
46 // TODO- why is this also defined (in a better way) in DWARFDefines.cpp?
47 const char *
48 DW_OP_value_to_name (uint32_t val)
49 {
50   static char invalid[100];
51   switch (val) {
52     case 0x03: return "DW_OP_addr";
53     case 0x06: return "DW_OP_deref";
54     case 0x08: return "DW_OP_const1u";
55     case 0x09: return "DW_OP_const1s";
56     case 0x0a: return "DW_OP_const2u";
57     case 0x0b: return "DW_OP_const2s";
58     case 0x0c: return "DW_OP_const4u";
59     case 0x0d: return "DW_OP_const4s";
60     case 0x0e: return "DW_OP_const8u";
61     case 0x0f: return "DW_OP_const8s";
62     case 0x10: return "DW_OP_constu";
63     case 0x11: return "DW_OP_consts";
64     case 0x12: return "DW_OP_dup";
65     case 0x13: return "DW_OP_drop";
66     case 0x14: return "DW_OP_over";
67     case 0x15: return "DW_OP_pick";
68     case 0x16: return "DW_OP_swap";
69     case 0x17: return "DW_OP_rot";
70     case 0x18: return "DW_OP_xderef";
71     case 0x19: return "DW_OP_abs";
72     case 0x1a: return "DW_OP_and";
73     case 0x1b: return "DW_OP_div";
74     case 0x1c: return "DW_OP_minus";
75     case 0x1d: return "DW_OP_mod";
76     case 0x1e: return "DW_OP_mul";
77     case 0x1f: return "DW_OP_neg";
78     case 0x20: return "DW_OP_not";
79     case 0x21: return "DW_OP_or";
80     case 0x22: return "DW_OP_plus";
81     case 0x23: return "DW_OP_plus_uconst";
82     case 0x24: return "DW_OP_shl";
83     case 0x25: return "DW_OP_shr";
84     case 0x26: return "DW_OP_shra";
85     case 0x27: return "DW_OP_xor";
86     case 0x2f: return "DW_OP_skip";
87     case 0x28: return "DW_OP_bra";
88     case 0x29: return "DW_OP_eq";
89     case 0x2a: return "DW_OP_ge";
90     case 0x2b: return "DW_OP_gt";
91     case 0x2c: return "DW_OP_le";
92     case 0x2d: return "DW_OP_lt";
93     case 0x2e: return "DW_OP_ne";
94     case 0x30: return "DW_OP_lit0";
95     case 0x31: return "DW_OP_lit1";
96     case 0x32: return "DW_OP_lit2";
97     case 0x33: return "DW_OP_lit3";
98     case 0x34: return "DW_OP_lit4";
99     case 0x35: return "DW_OP_lit5";
100     case 0x36: return "DW_OP_lit6";
101     case 0x37: return "DW_OP_lit7";
102     case 0x38: return "DW_OP_lit8";
103     case 0x39: return "DW_OP_lit9";
104     case 0x3a: return "DW_OP_lit10";
105     case 0x3b: return "DW_OP_lit11";
106     case 0x3c: return "DW_OP_lit12";
107     case 0x3d: return "DW_OP_lit13";
108     case 0x3e: return "DW_OP_lit14";
109     case 0x3f: return "DW_OP_lit15";
110     case 0x40: return "DW_OP_lit16";
111     case 0x41: return "DW_OP_lit17";
112     case 0x42: return "DW_OP_lit18";
113     case 0x43: return "DW_OP_lit19";
114     case 0x44: return "DW_OP_lit20";
115     case 0x45: return "DW_OP_lit21";
116     case 0x46: return "DW_OP_lit22";
117     case 0x47: return "DW_OP_lit23";
118     case 0x48: return "DW_OP_lit24";
119     case 0x49: return "DW_OP_lit25";
120     case 0x4a: return "DW_OP_lit26";
121     case 0x4b: return "DW_OP_lit27";
122     case 0x4c: return "DW_OP_lit28";
123     case 0x4d: return "DW_OP_lit29";
124     case 0x4e: return "DW_OP_lit30";
125     case 0x4f: return "DW_OP_lit31";
126     case 0x50: return "DW_OP_reg0";
127     case 0x51: return "DW_OP_reg1";
128     case 0x52: return "DW_OP_reg2";
129     case 0x53: return "DW_OP_reg3";
130     case 0x54: return "DW_OP_reg4";
131     case 0x55: return "DW_OP_reg5";
132     case 0x56: return "DW_OP_reg6";
133     case 0x57: return "DW_OP_reg7";
134     case 0x58: return "DW_OP_reg8";
135     case 0x59: return "DW_OP_reg9";
136     case 0x5a: return "DW_OP_reg10";
137     case 0x5b: return "DW_OP_reg11";
138     case 0x5c: return "DW_OP_reg12";
139     case 0x5d: return "DW_OP_reg13";
140     case 0x5e: return "DW_OP_reg14";
141     case 0x5f: return "DW_OP_reg15";
142     case 0x60: return "DW_OP_reg16";
143     case 0x61: return "DW_OP_reg17";
144     case 0x62: return "DW_OP_reg18";
145     case 0x63: return "DW_OP_reg19";
146     case 0x64: return "DW_OP_reg20";
147     case 0x65: return "DW_OP_reg21";
148     case 0x66: return "DW_OP_reg22";
149     case 0x67: return "DW_OP_reg23";
150     case 0x68: return "DW_OP_reg24";
151     case 0x69: return "DW_OP_reg25";
152     case 0x6a: return "DW_OP_reg26";
153     case 0x6b: return "DW_OP_reg27";
154     case 0x6c: return "DW_OP_reg28";
155     case 0x6d: return "DW_OP_reg29";
156     case 0x6e: return "DW_OP_reg30";
157     case 0x6f: return "DW_OP_reg31";
158     case 0x70: return "DW_OP_breg0";
159     case 0x71: return "DW_OP_breg1";
160     case 0x72: return "DW_OP_breg2";
161     case 0x73: return "DW_OP_breg3";
162     case 0x74: return "DW_OP_breg4";
163     case 0x75: return "DW_OP_breg5";
164     case 0x76: return "DW_OP_breg6";
165     case 0x77: return "DW_OP_breg7";
166     case 0x78: return "DW_OP_breg8";
167     case 0x79: return "DW_OP_breg9";
168     case 0x7a: return "DW_OP_breg10";
169     case 0x7b: return "DW_OP_breg11";
170     case 0x7c: return "DW_OP_breg12";
171     case 0x7d: return "DW_OP_breg13";
172     case 0x7e: return "DW_OP_breg14";
173     case 0x7f: return "DW_OP_breg15";
174     case 0x80: return "DW_OP_breg16";
175     case 0x81: return "DW_OP_breg17";
176     case 0x82: return "DW_OP_breg18";
177     case 0x83: return "DW_OP_breg19";
178     case 0x84: return "DW_OP_breg20";
179     case 0x85: return "DW_OP_breg21";
180     case 0x86: return "DW_OP_breg22";
181     case 0x87: return "DW_OP_breg23";
182     case 0x88: return "DW_OP_breg24";
183     case 0x89: return "DW_OP_breg25";
184     case 0x8a: return "DW_OP_breg26";
185     case 0x8b: return "DW_OP_breg27";
186     case 0x8c: return "DW_OP_breg28";
187     case 0x8d: return "DW_OP_breg29";
188     case 0x8e: return "DW_OP_breg30";
189     case 0x8f: return "DW_OP_breg31";
190     case 0x90: return "DW_OP_regx";
191     case 0x91: return "DW_OP_fbreg";
192     case 0x92: return "DW_OP_bregx";
193     case 0x93: return "DW_OP_piece";
194     case 0x94: return "DW_OP_deref_size";
195     case 0x95: return "DW_OP_xderef_size";
196     case 0x96: return "DW_OP_nop";
197     case 0x97: return "DW_OP_push_object_address";
198     case 0x98: return "DW_OP_call2";
199     case 0x99: return "DW_OP_call4";
200     case 0x9a: return "DW_OP_call_ref";
201     case 0xfb: return "DW_OP_GNU_addr_index";
202 //    case DW_OP_APPLE_array_ref: return "DW_OP_APPLE_array_ref";
203 //    case DW_OP_APPLE_extern: return "DW_OP_APPLE_extern";
204     case DW_OP_APPLE_uninit: return "DW_OP_APPLE_uninit";
205 //    case DW_OP_APPLE_assign: return "DW_OP_APPLE_assign";
206 //    case DW_OP_APPLE_address_of: return "DW_OP_APPLE_address_of";
207 //    case DW_OP_APPLE_value_of: return "DW_OP_APPLE_value_of";
208 //    case DW_OP_APPLE_deref_type: return "DW_OP_APPLE_deref_type";
209 //    case DW_OP_APPLE_expr_local: return "DW_OP_APPLE_expr_local";
210 //    case DW_OP_APPLE_constf: return "DW_OP_APPLE_constf";
211 //    case DW_OP_APPLE_scalar_cast: return "DW_OP_APPLE_scalar_cast";
212 //    case DW_OP_APPLE_clang_cast: return "DW_OP_APPLE_clang_cast";
213 //    case DW_OP_APPLE_clear: return "DW_OP_APPLE_clear";
214 //    case DW_OP_APPLE_error: return "DW_OP_APPLE_error";
215     default:
216        snprintf (invalid, sizeof(invalid), "Unknown DW_OP constant: 0x%x", val);
217        return invalid;
218   }
219 }
220 
221 
222 //----------------------------------------------------------------------
223 // DWARFExpression constructor
224 //----------------------------------------------------------------------
225 DWARFExpression::DWARFExpression(DWARFCompileUnit* dwarf_cu) :
226     m_module_wp(),
227     m_data(),
228     m_dwarf_cu(dwarf_cu),
229     m_reg_kind (eRegisterKindDWARF),
230     m_loclist_slide (LLDB_INVALID_ADDRESS)
231 {
232 }
233 
234 DWARFExpression::DWARFExpression(const DWARFExpression& rhs) :
235     m_module_wp(rhs.m_module_wp),
236     m_data(rhs.m_data),
237     m_dwarf_cu(rhs.m_dwarf_cu),
238     m_reg_kind (rhs.m_reg_kind),
239     m_loclist_slide(rhs.m_loclist_slide)
240 {
241 }
242 
243 
244 DWARFExpression::DWARFExpression(lldb::ModuleSP module_sp,
245                                  const DataExtractor& data,
246                                  DWARFCompileUnit* dwarf_cu,
247                                  lldb::offset_t data_offset,
248                                  lldb::offset_t data_length) :
249     m_module_wp(),
250     m_data(data, data_offset, data_length),
251     m_dwarf_cu(dwarf_cu),
252     m_reg_kind (eRegisterKindDWARF),
253     m_loclist_slide(LLDB_INVALID_ADDRESS)
254 {
255     if (module_sp)
256         m_module_wp = module_sp;
257 }
258 
259 //----------------------------------------------------------------------
260 // Destructor
261 //----------------------------------------------------------------------
262 DWARFExpression::~DWARFExpression()
263 {
264 }
265 
266 
267 bool
268 DWARFExpression::IsValid() const
269 {
270     return m_data.GetByteSize() > 0;
271 }
272 
273 void
274 DWARFExpression::SetOpcodeData (const DataExtractor& data)
275 {
276     m_data = data;
277 }
278 
279 void
280 DWARFExpression::CopyOpcodeData (lldb::ModuleSP module_sp, const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length)
281 {
282     const uint8_t *bytes = data.PeekData(data_offset, data_length);
283     if (bytes)
284     {
285         m_module_wp = module_sp;
286         m_data.SetData(DataBufferSP(new DataBufferHeap(bytes, data_length)));
287         m_data.SetByteOrder(data.GetByteOrder());
288         m_data.SetAddressByteSize(data.GetAddressByteSize());
289     }
290 }
291 
292 void
293 DWARFExpression::CopyOpcodeData (const void *data,
294                                  lldb::offset_t data_length,
295                                  ByteOrder byte_order,
296                                  uint8_t addr_byte_size)
297 {
298     if (data && data_length)
299     {
300         m_data.SetData(DataBufferSP(new DataBufferHeap(data, data_length)));
301         m_data.SetByteOrder(byte_order);
302         m_data.SetAddressByteSize(addr_byte_size);
303     }
304 }
305 
306 void
307 DWARFExpression::CopyOpcodeData (uint64_t const_value,
308                                  lldb::offset_t const_value_byte_size,
309                                  uint8_t addr_byte_size)
310 {
311     if (const_value_byte_size)
312     {
313         m_data.SetData(DataBufferSP(new DataBufferHeap(&const_value, const_value_byte_size)));
314         m_data.SetByteOrder(endian::InlHostByteOrder());
315         m_data.SetAddressByteSize(addr_byte_size);
316     }
317 }
318 
319 void
320 DWARFExpression::SetOpcodeData (lldb::ModuleSP module_sp, const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length)
321 {
322     m_module_wp = module_sp;
323     m_data.SetData(data, data_offset, data_length);
324 }
325 
326 void
327 DWARFExpression::DumpLocation (Stream *s, lldb::offset_t offset, lldb::offset_t length, lldb::DescriptionLevel level, ABI *abi) const
328 {
329     if (!m_data.ValidOffsetForDataOfSize(offset, length))
330         return;
331     const lldb::offset_t start_offset = offset;
332     const lldb::offset_t end_offset = offset + length;
333     while (m_data.ValidOffset(offset) && offset < end_offset)
334     {
335         const lldb::offset_t op_offset = offset;
336         const uint8_t op = m_data.GetU8(&offset);
337 
338         switch (level)
339         {
340         default:
341             break;
342 
343         case lldb::eDescriptionLevelBrief:
344             if (offset > start_offset)
345                 s->PutChar(' ');
346             break;
347 
348         case lldb::eDescriptionLevelFull:
349         case lldb::eDescriptionLevelVerbose:
350             if (offset > start_offset)
351                 s->EOL();
352             s->Indent();
353             if (level == lldb::eDescriptionLevelFull)
354                 break;
355             // Fall through for verbose and print offset and DW_OP prefix..
356             s->Printf("0x%8.8" PRIx64 ": %s", op_offset, op >= DW_OP_APPLE_uninit ? "DW_OP_APPLE_" : "DW_OP_");
357             break;
358         }
359 
360         switch (op)
361         {
362         case DW_OP_addr:    *s << "DW_OP_addr(" << m_data.GetAddress(&offset) << ") "; break;         // 0x03 1 address
363         case DW_OP_deref:   *s << "DW_OP_deref"; break;                                               // 0x06
364         case DW_OP_const1u: s->Printf("DW_OP_const1u(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x08 1 1-byte constant
365         case DW_OP_const1s: s->Printf("DW_OP_const1s(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x09 1 1-byte constant
366         case DW_OP_const2u: s->Printf("DW_OP_const2u(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0a 1 2-byte constant
367         case DW_OP_const2s: s->Printf("DW_OP_const2s(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0b 1 2-byte constant
368         case DW_OP_const4u: s->Printf("DW_OP_const4u(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0c 1 4-byte constant
369         case DW_OP_const4s: s->Printf("DW_OP_const4s(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0d 1 4-byte constant
370         case DW_OP_const8u: s->Printf("DW_OP_const8u(0x%16.16" PRIx64 ") ", m_data.GetU64(&offset)); break;  // 0x0e 1 8-byte constant
371         case DW_OP_const8s: s->Printf("DW_OP_const8s(0x%16.16" PRIx64 ") ", m_data.GetU64(&offset)); break;  // 0x0f 1 8-byte constant
372         case DW_OP_constu:  s->Printf("DW_OP_constu(0x%" PRIx64 ") ", m_data.GetULEB128(&offset)); break;    // 0x10 1 ULEB128 constant
373         case DW_OP_consts:  s->Printf("DW_OP_consts(0x%" PRId64 ") ", m_data.GetSLEB128(&offset)); break;    // 0x11 1 SLEB128 constant
374         case DW_OP_dup:     s->PutCString("DW_OP_dup"); break;                                        // 0x12
375         case DW_OP_drop:    s->PutCString("DW_OP_drop"); break;                                       // 0x13
376         case DW_OP_over:    s->PutCString("DW_OP_over"); break;                                       // 0x14
377         case DW_OP_pick:    s->Printf("DW_OP_pick(0x%2.2x) ", m_data.GetU8(&offset)); break;          // 0x15 1 1-byte stack index
378         case DW_OP_swap:    s->PutCString("DW_OP_swap"); break;                                       // 0x16
379         case DW_OP_rot:     s->PutCString("DW_OP_rot"); break;                                        // 0x17
380         case DW_OP_xderef:  s->PutCString("DW_OP_xderef"); break;                                     // 0x18
381         case DW_OP_abs:     s->PutCString("DW_OP_abs"); break;                                        // 0x19
382         case DW_OP_and:     s->PutCString("DW_OP_and"); break;                                        // 0x1a
383         case DW_OP_div:     s->PutCString("DW_OP_div"); break;                                        // 0x1b
384         case DW_OP_minus:   s->PutCString("DW_OP_minus"); break;                                      // 0x1c
385         case DW_OP_mod:     s->PutCString("DW_OP_mod"); break;                                        // 0x1d
386         case DW_OP_mul:     s->PutCString("DW_OP_mul"); break;                                        // 0x1e
387         case DW_OP_neg:     s->PutCString("DW_OP_neg"); break;                                        // 0x1f
388         case DW_OP_not:     s->PutCString("DW_OP_not"); break;                                        // 0x20
389         case DW_OP_or:      s->PutCString("DW_OP_or"); break;                                         // 0x21
390         case DW_OP_plus:    s->PutCString("DW_OP_plus"); break;                                       // 0x22
391         case DW_OP_plus_uconst:                                                                 // 0x23 1 ULEB128 addend
392             s->Printf("DW_OP_plus_uconst(0x%" PRIx64 ") ", m_data.GetULEB128(&offset));
393             break;
394 
395         case DW_OP_shl:     s->PutCString("DW_OP_shl"); break;                                        // 0x24
396         case DW_OP_shr:     s->PutCString("DW_OP_shr"); break;                                        // 0x25
397         case DW_OP_shra:    s->PutCString("DW_OP_shra"); break;                                       // 0x26
398         case DW_OP_xor:     s->PutCString("DW_OP_xor"); break;                                        // 0x27
399         case DW_OP_skip:    s->Printf("DW_OP_skip(0x%4.4x)", m_data.GetU16(&offset)); break;          // 0x2f 1 signed 2-byte constant
400         case DW_OP_bra:     s->Printf("DW_OP_bra(0x%4.4x)", m_data.GetU16(&offset)); break;           // 0x28 1 signed 2-byte constant
401         case DW_OP_eq:      s->PutCString("DW_OP_eq"); break;                                         // 0x29
402         case DW_OP_ge:      s->PutCString("DW_OP_ge"); break;                                         // 0x2a
403         case DW_OP_gt:      s->PutCString("DW_OP_gt"); break;                                         // 0x2b
404         case DW_OP_le:      s->PutCString("DW_OP_le"); break;                                         // 0x2c
405         case DW_OP_lt:      s->PutCString("DW_OP_lt"); break;                                         // 0x2d
406         case DW_OP_ne:      s->PutCString("DW_OP_ne"); break;                                         // 0x2e
407 
408         case DW_OP_lit0:    // 0x30
409         case DW_OP_lit1:    // 0x31
410         case DW_OP_lit2:    // 0x32
411         case DW_OP_lit3:    // 0x33
412         case DW_OP_lit4:    // 0x34
413         case DW_OP_lit5:    // 0x35
414         case DW_OP_lit6:    // 0x36
415         case DW_OP_lit7:    // 0x37
416         case DW_OP_lit8:    // 0x38
417         case DW_OP_lit9:    // 0x39
418         case DW_OP_lit10:   // 0x3A
419         case DW_OP_lit11:   // 0x3B
420         case DW_OP_lit12:   // 0x3C
421         case DW_OP_lit13:   // 0x3D
422         case DW_OP_lit14:   // 0x3E
423         case DW_OP_lit15:   // 0x3F
424         case DW_OP_lit16:   // 0x40
425         case DW_OP_lit17:   // 0x41
426         case DW_OP_lit18:   // 0x42
427         case DW_OP_lit19:   // 0x43
428         case DW_OP_lit20:   // 0x44
429         case DW_OP_lit21:   // 0x45
430         case DW_OP_lit22:   // 0x46
431         case DW_OP_lit23:   // 0x47
432         case DW_OP_lit24:   // 0x48
433         case DW_OP_lit25:   // 0x49
434         case DW_OP_lit26:   // 0x4A
435         case DW_OP_lit27:   // 0x4B
436         case DW_OP_lit28:   // 0x4C
437         case DW_OP_lit29:   // 0x4D
438         case DW_OP_lit30:   // 0x4E
439         case DW_OP_lit31:   s->Printf("DW_OP_lit%i", op - DW_OP_lit0); break; // 0x4f
440 
441         case DW_OP_reg0:    // 0x50
442         case DW_OP_reg1:    // 0x51
443         case DW_OP_reg2:    // 0x52
444         case DW_OP_reg3:    // 0x53
445         case DW_OP_reg4:    // 0x54
446         case DW_OP_reg5:    // 0x55
447         case DW_OP_reg6:    // 0x56
448         case DW_OP_reg7:    // 0x57
449         case DW_OP_reg8:    // 0x58
450         case DW_OP_reg9:    // 0x59
451         case DW_OP_reg10:   // 0x5A
452         case DW_OP_reg11:   // 0x5B
453         case DW_OP_reg12:   // 0x5C
454         case DW_OP_reg13:   // 0x5D
455         case DW_OP_reg14:   // 0x5E
456         case DW_OP_reg15:   // 0x5F
457         case DW_OP_reg16:   // 0x60
458         case DW_OP_reg17:   // 0x61
459         case DW_OP_reg18:   // 0x62
460         case DW_OP_reg19:   // 0x63
461         case DW_OP_reg20:   // 0x64
462         case DW_OP_reg21:   // 0x65
463         case DW_OP_reg22:   // 0x66
464         case DW_OP_reg23:   // 0x67
465         case DW_OP_reg24:   // 0x68
466         case DW_OP_reg25:   // 0x69
467         case DW_OP_reg26:   // 0x6A
468         case DW_OP_reg27:   // 0x6B
469         case DW_OP_reg28:   // 0x6C
470         case DW_OP_reg29:   // 0x6D
471         case DW_OP_reg30:   // 0x6E
472         case DW_OP_reg31:   // 0x6F
473             {
474                 uint32_t reg_num = op - DW_OP_reg0;
475                 if (abi)
476                 {
477                     RegisterInfo reg_info;
478                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
479                     {
480                         if (reg_info.name)
481                         {
482                             s->PutCString (reg_info.name);
483                             break;
484                         }
485                         else if (reg_info.alt_name)
486                         {
487                             s->PutCString (reg_info.alt_name);
488                             break;
489                         }
490                     }
491                 }
492                 s->Printf("DW_OP_reg%u", reg_num); break;
493             }
494             break;
495 
496         case DW_OP_breg0:
497         case DW_OP_breg1:
498         case DW_OP_breg2:
499         case DW_OP_breg3:
500         case DW_OP_breg4:
501         case DW_OP_breg5:
502         case DW_OP_breg6:
503         case DW_OP_breg7:
504         case DW_OP_breg8:
505         case DW_OP_breg9:
506         case DW_OP_breg10:
507         case DW_OP_breg11:
508         case DW_OP_breg12:
509         case DW_OP_breg13:
510         case DW_OP_breg14:
511         case DW_OP_breg15:
512         case DW_OP_breg16:
513         case DW_OP_breg17:
514         case DW_OP_breg18:
515         case DW_OP_breg19:
516         case DW_OP_breg20:
517         case DW_OP_breg21:
518         case DW_OP_breg22:
519         case DW_OP_breg23:
520         case DW_OP_breg24:
521         case DW_OP_breg25:
522         case DW_OP_breg26:
523         case DW_OP_breg27:
524         case DW_OP_breg28:
525         case DW_OP_breg29:
526         case DW_OP_breg30:
527         case DW_OP_breg31:
528             {
529                 uint32_t reg_num = op - DW_OP_breg0;
530                 int64_t reg_offset = m_data.GetSLEB128(&offset);
531                 if (abi)
532                 {
533                     RegisterInfo reg_info;
534                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
535                     {
536                         if (reg_info.name)
537                         {
538                             s->Printf("[%s%+" PRIi64 "]", reg_info.name, reg_offset);
539                             break;
540                         }
541                         else if (reg_info.alt_name)
542                         {
543                             s->Printf("[%s%+" PRIi64 "]", reg_info.alt_name, reg_offset);
544                             break;
545                         }
546                     }
547                 }
548                 s->Printf("DW_OP_breg%i(0x%" PRIx64 ")", reg_num, reg_offset);
549             }
550             break;
551 
552         case DW_OP_regx:                                                    // 0x90 1 ULEB128 register
553             {
554                 uint32_t reg_num = m_data.GetULEB128(&offset);
555                 if (abi)
556                 {
557                     RegisterInfo reg_info;
558                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
559                     {
560                         if (reg_info.name)
561                         {
562                             s->PutCString (reg_info.name);
563                             break;
564                         }
565                         else if (reg_info.alt_name)
566                         {
567                             s->PutCString (reg_info.alt_name);
568                             break;
569                         }
570                     }
571                 }
572                 s->Printf("DW_OP_regx(%" PRIu32 ")", reg_num); break;
573             }
574             break;
575         case DW_OP_fbreg:                                                   // 0x91 1 SLEB128 offset
576             s->Printf("DW_OP_fbreg(%" PRIi64 ")",m_data.GetSLEB128(&offset));
577             break;
578         case DW_OP_bregx:                                                   // 0x92 2 ULEB128 register followed by SLEB128 offset
579             {
580                 uint32_t reg_num = m_data.GetULEB128(&offset);
581                 int64_t reg_offset = m_data.GetSLEB128(&offset);
582                 if (abi)
583                 {
584                     RegisterInfo reg_info;
585                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
586                     {
587                         if (reg_info.name)
588                         {
589                             s->Printf("[%s%+" PRIi64 "]", reg_info.name, reg_offset);
590                             break;
591                         }
592                         else if (reg_info.alt_name)
593                         {
594                             s->Printf("[%s%+" PRIi64 "]", reg_info.alt_name, reg_offset);
595                             break;
596                         }
597                     }
598                 }
599                 s->Printf("DW_OP_bregx(reg=%" PRIu32 ",offset=%" PRIi64 ")", reg_num, reg_offset);
600             }
601             break;
602         case DW_OP_piece:                                                   // 0x93 1 ULEB128 size of piece addressed
603             s->Printf("DW_OP_piece(0x%" PRIx64 ")", m_data.GetULEB128(&offset));
604             break;
605         case DW_OP_deref_size:                                              // 0x94 1 1-byte size of data retrieved
606             s->Printf("DW_OP_deref_size(0x%2.2x)", m_data.GetU8(&offset));
607             break;
608         case DW_OP_xderef_size:                                             // 0x95 1 1-byte size of data retrieved
609             s->Printf("DW_OP_xderef_size(0x%2.2x)", m_data.GetU8(&offset));
610             break;
611         case DW_OP_nop: s->PutCString("DW_OP_nop"); break;                                    // 0x96
612         case DW_OP_push_object_address: s->PutCString("DW_OP_push_object_address"); break;    // 0x97 DWARF3
613         case DW_OP_call2:                                                   // 0x98 DWARF3 1 2-byte offset of DIE
614             s->Printf("DW_OP_call2(0x%4.4x)", m_data.GetU16(&offset));
615             break;
616         case DW_OP_call4:                                                   // 0x99 DWARF3 1 4-byte offset of DIE
617             s->Printf("DW_OP_call4(0x%8.8x)", m_data.GetU32(&offset));
618             break;
619         case DW_OP_call_ref:                                                // 0x9a DWARF3 1 4- or 8-byte offset of DIE
620             s->Printf("DW_OP_call_ref(0x%8.8" PRIx64 ")", m_data.GetAddress(&offset));
621             break;
622 //      case DW_OP_call_frame_cfa: s << "call_frame_cfa"; break;            // 0x9c DWARF3
623 //      case DW_OP_bit_piece:                                               // 0x9d DWARF3 2
624 //          s->Printf("DW_OP_bit_piece(0x%x, 0x%x)", m_data.GetULEB128(&offset), m_data.GetULEB128(&offset));
625 //          break;
626 //      case DW_OP_lo_user:     s->PutCString("DW_OP_lo_user"); break;                        // 0xe0
627 //      case DW_OP_hi_user:     s->PutCString("DW_OP_hi_user"); break;                        // 0xff
628 //        case DW_OP_APPLE_extern:
629 //            s->Printf("DW_OP_APPLE_extern(%" PRIu64 ")", m_data.GetULEB128(&offset));
630 //            break;
631 //        case DW_OP_APPLE_array_ref:
632 //            s->PutCString("DW_OP_APPLE_array_ref");
633 //            break;
634         case DW_OP_form_tls_address:
635             s->PutCString("DW_OP_form_tls_address");  // 0x9b
636             break;
637         case DW_OP_GNU_addr_index:                                          // 0xfb
638             s->Printf("DW_OP_GNU_addr_index(0x%" PRIx64 ")", m_data.GetULEB128(&offset));
639             break;
640         case DW_OP_GNU_push_tls_address:
641             s->PutCString("DW_OP_GNU_push_tls_address");  // 0xe0
642             break;
643         case DW_OP_APPLE_uninit:
644             s->PutCString("DW_OP_APPLE_uninit");  // 0xF0
645             break;
646 //        case DW_OP_APPLE_assign:        // 0xF1 - pops value off and assigns it to second item on stack (2nd item must have assignable context)
647 //            s->PutCString("DW_OP_APPLE_assign");
648 //            break;
649 //        case DW_OP_APPLE_address_of:    // 0xF2 - gets the address of the top stack item (top item must be a variable, or have value_type that is an address already)
650 //            s->PutCString("DW_OP_APPLE_address_of");
651 //            break;
652 //        case DW_OP_APPLE_value_of:      // 0xF3 - pops the value off the stack and pushes the value of that object (top item must be a variable, or expression local)
653 //            s->PutCString("DW_OP_APPLE_value_of");
654 //            break;
655 //        case DW_OP_APPLE_deref_type:    // 0xF4 - gets the address of the top stack item (top item must be a variable, or a clang type)
656 //            s->PutCString("DW_OP_APPLE_deref_type");
657 //            break;
658 //        case DW_OP_APPLE_expr_local:    // 0xF5 - ULEB128 expression local index
659 //            s->Printf("DW_OP_APPLE_expr_local(%" PRIu64 ")", m_data.GetULEB128(&offset));
660 //            break;
661 //        case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
662 //            {
663 //                uint8_t float_length = m_data.GetU8(&offset);
664 //                s->Printf("DW_OP_APPLE_constf(<%u> ", float_length);
665 //                m_data.Dump(s, offset, eFormatHex, float_length, 1, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
666 //                s->PutChar(')');
667 //                // Consume the float data
668 //                m_data.GetData(&offset, float_length);
669 //            }
670 //            break;
671 //        case DW_OP_APPLE_scalar_cast:
672 //            s->Printf("DW_OP_APPLE_scalar_cast(%s)", Scalar::GetValueTypeAsCString ((Scalar::Type)m_data.GetU8(&offset)));
673 //            break;
674 //        case DW_OP_APPLE_clang_cast:
675 //            {
676 //                clang::Type *clang_type = (clang::Type *)m_data.GetMaxU64(&offset, sizeof(void*));
677 //                s->Printf("DW_OP_APPLE_clang_cast(%p)", clang_type);
678 //            }
679 //            break;
680 //        case DW_OP_APPLE_clear:
681 //            s->PutCString("DW_OP_APPLE_clear");
682 //            break;
683 //        case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
684 //            s->PutCString("DW_OP_APPLE_error");
685 //            break;
686         }
687     }
688 }
689 
690 void
691 DWARFExpression::SetLocationListSlide (addr_t slide)
692 {
693     m_loclist_slide = slide;
694 }
695 
696 int
697 DWARFExpression::GetRegisterKind ()
698 {
699     return m_reg_kind;
700 }
701 
702 void
703 DWARFExpression::SetRegisterKind (RegisterKind reg_kind)
704 {
705     m_reg_kind = reg_kind;
706 }
707 
708 bool
709 DWARFExpression::IsLocationList() const
710 {
711     return m_loclist_slide != LLDB_INVALID_ADDRESS;
712 }
713 
714 void
715 DWARFExpression::GetDescription (Stream *s, lldb::DescriptionLevel level, addr_t location_list_base_addr, ABI *abi) const
716 {
717     if (IsLocationList())
718     {
719         // We have a location list
720         lldb::offset_t offset = 0;
721         uint32_t count = 0;
722         addr_t curr_base_addr = location_list_base_addr;
723         while (m_data.ValidOffset(offset))
724         {
725             lldb::addr_t begin_addr_offset = m_data.GetAddress(&offset);
726             lldb::addr_t end_addr_offset = m_data.GetAddress(&offset);
727             if (begin_addr_offset < end_addr_offset)
728             {
729                 if (count > 0)
730                     s->PutCString(", ");
731                 VMRange addr_range(curr_base_addr + begin_addr_offset, curr_base_addr + end_addr_offset);
732                 addr_range.Dump(s, 0, 8);
733                 s->PutChar('{');
734                 lldb::offset_t location_length = m_data.GetU16(&offset);
735                 DumpLocation (s, offset, location_length, level, abi);
736                 s->PutChar('}');
737                 offset += location_length;
738             }
739             else if (begin_addr_offset == 0 && end_addr_offset == 0)
740             {
741                 // The end of the location list is marked by both the start and end offset being zero
742                 break;
743             }
744             else
745             {
746                 if ((m_data.GetAddressByteSize() == 4 && (begin_addr_offset == UINT32_MAX)) ||
747                     (m_data.GetAddressByteSize() == 8 && (begin_addr_offset == UINT64_MAX)))
748                 {
749                     curr_base_addr = end_addr_offset + location_list_base_addr;
750                     // We have a new base address
751                     if (count > 0)
752                         s->PutCString(", ");
753                     *s << "base_addr = " << end_addr_offset;
754                 }
755             }
756 
757             count++;
758         }
759     }
760     else
761     {
762         // We have a normal location that contains DW_OP location opcodes
763         DumpLocation (s, 0, m_data.GetByteSize(), level, abi);
764     }
765 }
766 
767 static bool
768 ReadRegisterValueAsScalar
769 (
770     RegisterContext *reg_ctx,
771     lldb::RegisterKind reg_kind,
772     uint32_t reg_num,
773     Error *error_ptr,
774     Value &value
775 )
776 {
777     if (reg_ctx == NULL)
778     {
779         if (error_ptr)
780             error_ptr->SetErrorStringWithFormat("No register context in frame.\n");
781     }
782     else
783     {
784         uint32_t native_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
785         if (native_reg == LLDB_INVALID_REGNUM)
786         {
787             if (error_ptr)
788                 error_ptr->SetErrorStringWithFormat("Unable to convert register kind=%u reg_num=%u to a native register number.\n", reg_kind, reg_num);
789         }
790         else
791         {
792             const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(native_reg);
793             RegisterValue reg_value;
794             if (reg_ctx->ReadRegister (reg_info, reg_value))
795             {
796                 if (reg_value.GetScalarValue(value.GetScalar()))
797                 {
798                     value.SetValueType (Value::eValueTypeScalar);
799                     value.SetContext (Value::eContextTypeRegisterInfo,
800                                       const_cast<RegisterInfo *>(reg_info));
801                     if (error_ptr)
802                         error_ptr->Clear();
803                     return true;
804                 }
805                 else
806                 {
807                     // If we get this error, then we need to implement a value
808                     // buffer in the dwarf expression evaluation function...
809                     if (error_ptr)
810                         error_ptr->SetErrorStringWithFormat ("register %s can't be converted to a scalar value",
811                                                              reg_info->name);
812                 }
813             }
814             else
815             {
816                 if (error_ptr)
817                     error_ptr->SetErrorStringWithFormat("register %s is not available", reg_info->name);
818             }
819         }
820     }
821     return false;
822 }
823 
824 //bool
825 //DWARFExpression::LocationListContainsLoadAddress (Process* process, const Address &addr) const
826 //{
827 //    return LocationListContainsLoadAddress(process, addr.GetLoadAddress(process));
828 //}
829 //
830 //bool
831 //DWARFExpression::LocationListContainsLoadAddress (Process* process, addr_t load_addr) const
832 //{
833 //    if (load_addr == LLDB_INVALID_ADDRESS)
834 //        return false;
835 //
836 //    if (IsLocationList())
837 //    {
838 //        lldb::offset_t offset = 0;
839 //
840 //        addr_t loc_list_base_addr = m_loclist_slide.GetLoadAddress(process);
841 //
842 //        if (loc_list_base_addr == LLDB_INVALID_ADDRESS)
843 //            return false;
844 //
845 //        while (m_data.ValidOffset(offset))
846 //        {
847 //            // We need to figure out what the value is for the location.
848 //            addr_t lo_pc = m_data.GetAddress(&offset);
849 //            addr_t hi_pc = m_data.GetAddress(&offset);
850 //            if (lo_pc == 0 && hi_pc == 0)
851 //                break;
852 //            else
853 //            {
854 //                lo_pc += loc_list_base_addr;
855 //                hi_pc += loc_list_base_addr;
856 //
857 //                if (lo_pc <= load_addr && load_addr < hi_pc)
858 //                    return true;
859 //
860 //                offset += m_data.GetU16(&offset);
861 //            }
862 //        }
863 //    }
864 //    return false;
865 //}
866 
867 static offset_t
868 GetOpcodeDataSize (const DataExtractor &data, const lldb::offset_t data_offset, const uint8_t op)
869 {
870     lldb::offset_t offset = data_offset;
871     switch (op)
872     {
873         case DW_OP_addr:
874         case DW_OP_call_ref:    // 0x9a 1 address sized offset of DIE (DWARF3)
875             return data.GetAddressByteSize();
876 
877         // Opcodes with no arguments
878         case DW_OP_deref:   // 0x06
879         case DW_OP_dup:     // 0x12
880         case DW_OP_drop:    // 0x13
881         case DW_OP_over:    // 0x14
882         case DW_OP_swap:    // 0x16
883         case DW_OP_rot:     // 0x17
884         case DW_OP_xderef:  // 0x18
885         case DW_OP_abs:     // 0x19
886         case DW_OP_and:     // 0x1a
887         case DW_OP_div:     // 0x1b
888         case DW_OP_minus:   // 0x1c
889         case DW_OP_mod:     // 0x1d
890         case DW_OP_mul:     // 0x1e
891         case DW_OP_neg:     // 0x1f
892         case DW_OP_not:     // 0x20
893         case DW_OP_or:      // 0x21
894         case DW_OP_plus:    // 0x22
895         case DW_OP_shl:     // 0x24
896         case DW_OP_shr:     // 0x25
897         case DW_OP_shra:    // 0x26
898         case DW_OP_xor:     // 0x27
899         case DW_OP_eq:      // 0x29
900         case DW_OP_ge:      // 0x2a
901         case DW_OP_gt:      // 0x2b
902         case DW_OP_le:      // 0x2c
903         case DW_OP_lt:      // 0x2d
904         case DW_OP_ne:      // 0x2e
905         case DW_OP_lit0:    // 0x30
906         case DW_OP_lit1:    // 0x31
907         case DW_OP_lit2:    // 0x32
908         case DW_OP_lit3:    // 0x33
909         case DW_OP_lit4:    // 0x34
910         case DW_OP_lit5:    // 0x35
911         case DW_OP_lit6:    // 0x36
912         case DW_OP_lit7:    // 0x37
913         case DW_OP_lit8:    // 0x38
914         case DW_OP_lit9:    // 0x39
915         case DW_OP_lit10:   // 0x3A
916         case DW_OP_lit11:   // 0x3B
917         case DW_OP_lit12:   // 0x3C
918         case DW_OP_lit13:   // 0x3D
919         case DW_OP_lit14:   // 0x3E
920         case DW_OP_lit15:   // 0x3F
921         case DW_OP_lit16:   // 0x40
922         case DW_OP_lit17:   // 0x41
923         case DW_OP_lit18:   // 0x42
924         case DW_OP_lit19:   // 0x43
925         case DW_OP_lit20:   // 0x44
926         case DW_OP_lit21:   // 0x45
927         case DW_OP_lit22:   // 0x46
928         case DW_OP_lit23:   // 0x47
929         case DW_OP_lit24:   // 0x48
930         case DW_OP_lit25:   // 0x49
931         case DW_OP_lit26:   // 0x4A
932         case DW_OP_lit27:   // 0x4B
933         case DW_OP_lit28:   // 0x4C
934         case DW_OP_lit29:   // 0x4D
935         case DW_OP_lit30:   // 0x4E
936         case DW_OP_lit31:   // 0x4f
937         case DW_OP_reg0:    // 0x50
938         case DW_OP_reg1:    // 0x51
939         case DW_OP_reg2:    // 0x52
940         case DW_OP_reg3:    // 0x53
941         case DW_OP_reg4:    // 0x54
942         case DW_OP_reg5:    // 0x55
943         case DW_OP_reg6:    // 0x56
944         case DW_OP_reg7:    // 0x57
945         case DW_OP_reg8:    // 0x58
946         case DW_OP_reg9:    // 0x59
947         case DW_OP_reg10:   // 0x5A
948         case DW_OP_reg11:   // 0x5B
949         case DW_OP_reg12:   // 0x5C
950         case DW_OP_reg13:   // 0x5D
951         case DW_OP_reg14:   // 0x5E
952         case DW_OP_reg15:   // 0x5F
953         case DW_OP_reg16:   // 0x60
954         case DW_OP_reg17:   // 0x61
955         case DW_OP_reg18:   // 0x62
956         case DW_OP_reg19:   // 0x63
957         case DW_OP_reg20:   // 0x64
958         case DW_OP_reg21:   // 0x65
959         case DW_OP_reg22:   // 0x66
960         case DW_OP_reg23:   // 0x67
961         case DW_OP_reg24:   // 0x68
962         case DW_OP_reg25:   // 0x69
963         case DW_OP_reg26:   // 0x6A
964         case DW_OP_reg27:   // 0x6B
965         case DW_OP_reg28:   // 0x6C
966         case DW_OP_reg29:   // 0x6D
967         case DW_OP_reg30:   // 0x6E
968         case DW_OP_reg31:   // 0x6F
969         case DW_OP_nop:     // 0x96
970         case DW_OP_push_object_address: // 0x97 DWARF3
971         case DW_OP_form_tls_address:    // 0x9b DWARF3
972         case DW_OP_call_frame_cfa:      // 0x9c DWARF3
973         case DW_OP_stack_value: // 0x9f DWARF4
974         case DW_OP_GNU_push_tls_address: // 0xe0 GNU extension
975             return 0;
976 
977         // Opcodes with a single 1 byte arguments
978         case DW_OP_const1u:     // 0x08 1 1-byte constant
979         case DW_OP_const1s:     // 0x09 1 1-byte constant
980         case DW_OP_pick:        // 0x15 1 1-byte stack index
981         case DW_OP_deref_size:  // 0x94 1 1-byte size of data retrieved
982         case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
983             return 1;
984 
985         // Opcodes with a single 2 byte arguments
986         case DW_OP_const2u:     // 0x0a 1 2-byte constant
987         case DW_OP_const2s:     // 0x0b 1 2-byte constant
988         case DW_OP_skip:        // 0x2f 1 signed 2-byte constant
989         case DW_OP_bra:         // 0x28 1 signed 2-byte constant
990         case DW_OP_call2:       // 0x98 1 2-byte offset of DIE (DWARF3)
991             return 2;
992 
993         // Opcodes with a single 4 byte arguments
994         case DW_OP_const4u:     // 0x0c 1 4-byte constant
995         case DW_OP_const4s:     // 0x0d 1 4-byte constant
996         case DW_OP_call4:       // 0x99 1 4-byte offset of DIE (DWARF3)
997             return 4;
998 
999         // Opcodes with a single 8 byte arguments
1000         case DW_OP_const8u:     // 0x0e 1 8-byte constant
1001         case DW_OP_const8s:     // 0x0f 1 8-byte constant
1002              return 8;
1003 
1004         // All opcodes that have a single ULEB (signed or unsigned) argument
1005         case DW_OP_constu:      // 0x10 1 ULEB128 constant
1006         case DW_OP_consts:      // 0x11 1 SLEB128 constant
1007         case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
1008         case DW_OP_breg0:       // 0x70 1 ULEB128 register
1009         case DW_OP_breg1:       // 0x71 1 ULEB128 register
1010         case DW_OP_breg2:       // 0x72 1 ULEB128 register
1011         case DW_OP_breg3:       // 0x73 1 ULEB128 register
1012         case DW_OP_breg4:       // 0x74 1 ULEB128 register
1013         case DW_OP_breg5:       // 0x75 1 ULEB128 register
1014         case DW_OP_breg6:       // 0x76 1 ULEB128 register
1015         case DW_OP_breg7:       // 0x77 1 ULEB128 register
1016         case DW_OP_breg8:       // 0x78 1 ULEB128 register
1017         case DW_OP_breg9:       // 0x79 1 ULEB128 register
1018         case DW_OP_breg10:      // 0x7a 1 ULEB128 register
1019         case DW_OP_breg11:      // 0x7b 1 ULEB128 register
1020         case DW_OP_breg12:      // 0x7c 1 ULEB128 register
1021         case DW_OP_breg13:      // 0x7d 1 ULEB128 register
1022         case DW_OP_breg14:      // 0x7e 1 ULEB128 register
1023         case DW_OP_breg15:      // 0x7f 1 ULEB128 register
1024         case DW_OP_breg16:      // 0x80 1 ULEB128 register
1025         case DW_OP_breg17:      // 0x81 1 ULEB128 register
1026         case DW_OP_breg18:      // 0x82 1 ULEB128 register
1027         case DW_OP_breg19:      // 0x83 1 ULEB128 register
1028         case DW_OP_breg20:      // 0x84 1 ULEB128 register
1029         case DW_OP_breg21:      // 0x85 1 ULEB128 register
1030         case DW_OP_breg22:      // 0x86 1 ULEB128 register
1031         case DW_OP_breg23:      // 0x87 1 ULEB128 register
1032         case DW_OP_breg24:      // 0x88 1 ULEB128 register
1033         case DW_OP_breg25:      // 0x89 1 ULEB128 register
1034         case DW_OP_breg26:      // 0x8a 1 ULEB128 register
1035         case DW_OP_breg27:      // 0x8b 1 ULEB128 register
1036         case DW_OP_breg28:      // 0x8c 1 ULEB128 register
1037         case DW_OP_breg29:      // 0x8d 1 ULEB128 register
1038         case DW_OP_breg30:      // 0x8e 1 ULEB128 register
1039         case DW_OP_breg31:      // 0x8f 1 ULEB128 register
1040         case DW_OP_regx:        // 0x90 1 ULEB128 register
1041         case DW_OP_fbreg:       // 0x91 1 SLEB128 offset
1042         case DW_OP_piece:       // 0x93 1 ULEB128 size of piece addressed
1043         case DW_OP_GNU_addr_index: // 0xfb 1 ULEB128 index
1044             data.Skip_LEB128(&offset);
1045             return offset - data_offset;
1046 
1047             // All opcodes that have a 2 ULEB (signed or unsigned) arguments
1048         case DW_OP_bregx:       // 0x92 2 ULEB128 register followed by SLEB128 offset
1049         case DW_OP_bit_piece:   // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
1050             data.Skip_LEB128(&offset);
1051             data.Skip_LEB128(&offset);
1052             return offset - data_offset;
1053 
1054         case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size (DWARF4)
1055             {
1056                 uint64_t block_len = data.Skip_LEB128(&offset);
1057                 offset += block_len;
1058                 return offset - data_offset;
1059             }
1060 
1061         default:
1062             break;
1063     }
1064     return LLDB_INVALID_OFFSET;
1065 }
1066 
1067 lldb::addr_t
1068 DWARFExpression::GetLocation_DW_OP_addr (uint32_t op_addr_idx,
1069                                          bool &error) const
1070 {
1071     error = false;
1072     if (IsLocationList())
1073         return LLDB_INVALID_ADDRESS;
1074     lldb::offset_t offset = 0;
1075     uint32_t curr_op_addr_idx = 0;
1076     while (m_data.ValidOffset(offset))
1077     {
1078         const uint8_t op = m_data.GetU8(&offset);
1079 
1080         if (op == DW_OP_addr)
1081         {
1082             const lldb::addr_t op_file_addr = m_data.GetAddress(&offset);
1083             if (curr_op_addr_idx == op_addr_idx)
1084                 return op_file_addr;
1085             else
1086                 ++curr_op_addr_idx;
1087         }
1088         else if (op == DW_OP_GNU_addr_index)
1089         {
1090             uint64_t index = m_data.GetULEB128(&offset);
1091             if (curr_op_addr_idx == op_addr_idx)
1092             {
1093                 if (!m_dwarf_cu)
1094                 {
1095                     error = true;
1096                     break;
1097                 }
1098 
1099                 uint32_t index_size = m_dwarf_cu->GetAddressByteSize();
1100                 dw_offset_t addr_base = m_dwarf_cu->GetAddrBase();
1101                 lldb::offset_t offset = addr_base + index * index_size;
1102                 return m_dwarf_cu->GetSymbolFileDWARF()->get_debug_addr_data().GetMaxU64(&offset, index_size);
1103             }
1104             else
1105                 ++curr_op_addr_idx;
1106         }
1107         else
1108         {
1109             const offset_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1110             if (op_arg_size == LLDB_INVALID_OFFSET)
1111             {
1112                 error = true;
1113                 break;
1114             }
1115             offset += op_arg_size;
1116         }
1117     }
1118     return LLDB_INVALID_ADDRESS;
1119 }
1120 
1121 bool
1122 DWARFExpression::Update_DW_OP_addr (lldb::addr_t file_addr)
1123 {
1124     if (IsLocationList())
1125         return false;
1126     lldb::offset_t offset = 0;
1127     while (m_data.ValidOffset(offset))
1128     {
1129         const uint8_t op = m_data.GetU8(&offset);
1130 
1131         if (op == DW_OP_addr)
1132         {
1133             const uint32_t addr_byte_size = m_data.GetAddressByteSize();
1134             // We have to make a copy of the data as we don't know if this
1135             // data is from a read only memory mapped buffer, so we duplicate
1136             // all of the data first, then modify it, and if all goes well,
1137             // we then replace the data for this expression
1138 
1139             // So first we copy the data into a heap buffer
1140             std::unique_ptr<DataBufferHeap> head_data_ap (new DataBufferHeap (m_data.GetDataStart(),
1141                                                                               m_data.GetByteSize()));
1142 
1143             // Make en encoder so we can write the address into the buffer using
1144             // the correct byte order (endianness)
1145             DataEncoder encoder (head_data_ap->GetBytes(),
1146                                  head_data_ap->GetByteSize(),
1147                                  m_data.GetByteOrder(),
1148                                  addr_byte_size);
1149 
1150             // Replace the address in the new buffer
1151             if (encoder.PutMaxU64 (offset, addr_byte_size, file_addr) == UINT32_MAX)
1152                 return false;
1153 
1154             // All went well, so now we can reset the data using a shared
1155             // pointer to the heap data so "m_data" will now correctly
1156             // manage the heap data.
1157             m_data.SetData (DataBufferSP (head_data_ap.release()));
1158             return true;
1159         }
1160         else
1161         {
1162             const offset_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1163             if (op_arg_size == LLDB_INVALID_OFFSET)
1164                 break;
1165             offset += op_arg_size;
1166         }
1167     }
1168     return false;
1169 }
1170 
1171 bool
1172 DWARFExpression::LocationListContainsAddress (lldb::addr_t loclist_base_addr, lldb::addr_t addr) const
1173 {
1174     if (addr == LLDB_INVALID_ADDRESS)
1175         return false;
1176 
1177     if (IsLocationList())
1178     {
1179         lldb::offset_t offset = 0;
1180 
1181         if (loclist_base_addr == LLDB_INVALID_ADDRESS)
1182             return false;
1183 
1184         while (m_data.ValidOffset(offset))
1185         {
1186             // We need to figure out what the value is for the location.
1187             addr_t lo_pc = m_data.GetAddress(&offset);
1188             addr_t hi_pc = m_data.GetAddress(&offset);
1189             if (lo_pc == 0 && hi_pc == 0)
1190                 break;
1191             else
1192             {
1193                 lo_pc += loclist_base_addr - m_loclist_slide;
1194                 hi_pc += loclist_base_addr - m_loclist_slide;
1195 
1196                 if (lo_pc <= addr && addr < hi_pc)
1197                     return true;
1198 
1199                 offset += m_data.GetU16(&offset);
1200             }
1201         }
1202     }
1203     return false;
1204 }
1205 
1206 bool
1207 DWARFExpression::GetLocation (addr_t base_addr, addr_t pc, lldb::offset_t &offset, lldb::offset_t &length)
1208 {
1209     offset = 0;
1210     if (!IsLocationList())
1211     {
1212         length = m_data.GetByteSize();
1213         return true;
1214     }
1215 
1216     if (base_addr != LLDB_INVALID_ADDRESS && pc != LLDB_INVALID_ADDRESS)
1217     {
1218         addr_t curr_base_addr = base_addr;
1219 
1220         while (m_data.ValidOffset(offset))
1221         {
1222             // We need to figure out what the value is for the location.
1223             addr_t lo_pc = m_data.GetAddress(&offset);
1224             addr_t hi_pc = m_data.GetAddress(&offset);
1225             if (lo_pc == 0 && hi_pc == 0)
1226             {
1227                 break;
1228             }
1229             else
1230             {
1231                 lo_pc += curr_base_addr - m_loclist_slide;
1232                 hi_pc += curr_base_addr - m_loclist_slide;
1233 
1234                 length = m_data.GetU16(&offset);
1235 
1236                 if (length > 0 && lo_pc <= pc && pc < hi_pc)
1237                     return true;
1238 
1239                 offset += length;
1240             }
1241         }
1242     }
1243     offset = LLDB_INVALID_OFFSET;
1244     length = 0;
1245     return false;
1246 }
1247 
1248 bool
1249 DWARFExpression::DumpLocationForAddress (Stream *s,
1250                                          lldb::DescriptionLevel level,
1251                                          addr_t base_addr,
1252                                          addr_t address,
1253                                          ABI *abi)
1254 {
1255     lldb::offset_t offset = 0;
1256     lldb::offset_t length = 0;
1257 
1258     if (GetLocation (base_addr, address, offset, length))
1259     {
1260         if (length > 0)
1261         {
1262             DumpLocation(s, offset, length, level, abi);
1263             return true;
1264         }
1265     }
1266     return false;
1267 }
1268 
1269 bool
1270 DWARFExpression::Evaluate
1271 (
1272     ExecutionContextScope *exe_scope,
1273     ClangExpressionVariableList *expr_locals,
1274     ClangExpressionDeclMap *decl_map,
1275     lldb::addr_t loclist_base_load_addr,
1276     const Value* initial_value_ptr,
1277     Value& result,
1278     Error *error_ptr
1279 ) const
1280 {
1281     ExecutionContext exe_ctx (exe_scope);
1282     return Evaluate(&exe_ctx, expr_locals, decl_map, NULL, loclist_base_load_addr, initial_value_ptr, result, error_ptr);
1283 }
1284 
1285 bool
1286 DWARFExpression::Evaluate
1287 (
1288     ExecutionContext *exe_ctx,
1289     ClangExpressionVariableList *expr_locals,
1290     ClangExpressionDeclMap *decl_map,
1291     RegisterContext *reg_ctx,
1292     lldb::addr_t loclist_base_load_addr,
1293     const Value* initial_value_ptr,
1294     Value& result,
1295     Error *error_ptr
1296 ) const
1297 {
1298     ModuleSP module_sp = m_module_wp.lock();
1299 
1300     if (IsLocationList())
1301     {
1302         lldb::offset_t offset = 0;
1303         addr_t pc;
1304         StackFrame *frame = NULL;
1305         if (reg_ctx)
1306             pc = reg_ctx->GetPC();
1307         else
1308         {
1309             frame = exe_ctx->GetFramePtr();
1310             if (!frame)
1311                 return false;
1312             RegisterContextSP reg_ctx_sp = frame->GetRegisterContext();
1313             if (!reg_ctx_sp)
1314                 return false;
1315             pc = reg_ctx_sp->GetPC();
1316         }
1317 
1318         if (loclist_base_load_addr != LLDB_INVALID_ADDRESS)
1319         {
1320             if (pc == LLDB_INVALID_ADDRESS)
1321             {
1322                 if (error_ptr)
1323                     error_ptr->SetErrorString("Invalid PC in frame.");
1324                 return false;
1325             }
1326 
1327             addr_t curr_loclist_base_load_addr = loclist_base_load_addr;
1328 
1329             while (m_data.ValidOffset(offset))
1330             {
1331                 // We need to figure out what the value is for the location.
1332                 addr_t lo_pc = m_data.GetAddress(&offset);
1333                 addr_t hi_pc = m_data.GetAddress(&offset);
1334                 if (lo_pc == 0 && hi_pc == 0)
1335                 {
1336                     break;
1337                 }
1338                 else
1339                 {
1340                     lo_pc += curr_loclist_base_load_addr - m_loclist_slide;
1341                     hi_pc += curr_loclist_base_load_addr - m_loclist_slide;
1342 
1343                     uint16_t length = m_data.GetU16(&offset);
1344 
1345                     if (length > 0 && lo_pc <= pc && pc < hi_pc)
1346                     {
1347                         return DWARFExpression::Evaluate (exe_ctx,
1348                                                           expr_locals,
1349                                                           decl_map,
1350                                                           reg_ctx,
1351                                                           module_sp,
1352                                                           m_data,
1353                                                           m_dwarf_cu,
1354                                                           offset,
1355                                                           length,
1356                                                           m_reg_kind,
1357                                                           initial_value_ptr,
1358                                                           result,
1359                                                           error_ptr);
1360                     }
1361                     offset += length;
1362                 }
1363             }
1364         }
1365         if (error_ptr)
1366             error_ptr->SetErrorString ("variable not available");
1367         return false;
1368     }
1369 
1370     // Not a location list, just a single expression.
1371     return DWARFExpression::Evaluate (exe_ctx,
1372                                       expr_locals,
1373                                       decl_map,
1374                                       reg_ctx,
1375                                       module_sp,
1376                                       m_data,
1377                                       m_dwarf_cu,
1378                                       0,
1379                                       m_data.GetByteSize(),
1380                                       m_reg_kind,
1381                                       initial_value_ptr,
1382                                       result,
1383                                       error_ptr);
1384 }
1385 
1386 
1387 
1388 bool
1389 DWARFExpression::Evaluate
1390 (
1391     ExecutionContext *exe_ctx,
1392     ClangExpressionVariableList *expr_locals,
1393     ClangExpressionDeclMap *decl_map,
1394     RegisterContext *reg_ctx,
1395     lldb::ModuleSP module_sp,
1396     const DataExtractor& opcodes,
1397     DWARFCompileUnit* dwarf_cu,
1398     const lldb::offset_t opcodes_offset,
1399     const lldb::offset_t opcodes_length,
1400     const lldb::RegisterKind reg_kind,
1401     const Value* initial_value_ptr,
1402     Value& result,
1403     Error *error_ptr
1404 )
1405 {
1406 
1407     if (opcodes_length == 0)
1408     {
1409         if (error_ptr)
1410             error_ptr->SetErrorString ("no location, value may have been optimized out");
1411         return false;
1412     }
1413     std::vector<Value> stack;
1414 
1415     Process *process = NULL;
1416     StackFrame *frame = NULL;
1417 
1418     if (exe_ctx)
1419     {
1420         process = exe_ctx->GetProcessPtr();
1421         frame = exe_ctx->GetFramePtr();
1422     }
1423     if (reg_ctx == NULL && frame)
1424         reg_ctx = frame->GetRegisterContext().get();
1425 
1426     if (initial_value_ptr)
1427         stack.push_back(*initial_value_ptr);
1428 
1429     lldb::offset_t offset = opcodes_offset;
1430     const lldb::offset_t end_offset = opcodes_offset + opcodes_length;
1431     Value tmp;
1432     uint32_t reg_num;
1433 
1434     /// Insertion point for evaluating multi-piece expression.
1435     uint64_t op_piece_offset = 0;
1436     Value pieces; // Used for DW_OP_piece
1437 
1438     // Make sure all of the data is available in opcodes.
1439     if (!opcodes.ValidOffsetForDataOfSize(opcodes_offset, opcodes_length))
1440     {
1441         if (error_ptr)
1442             error_ptr->SetErrorString ("invalid offset and/or length for opcodes buffer.");
1443         return false;
1444     }
1445     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1446 
1447 
1448     while (opcodes.ValidOffset(offset) && offset < end_offset)
1449     {
1450         const lldb::offset_t op_offset = offset;
1451         const uint8_t op = opcodes.GetU8(&offset);
1452 
1453         if (log && log->GetVerbose())
1454         {
1455             size_t count = stack.size();
1456             log->Printf("Stack before operation has %" PRIu64 " values:", (uint64_t)count);
1457             for (size_t i=0; i<count; ++i)
1458             {
1459                 StreamString new_value;
1460                 new_value.Printf("[%" PRIu64 "]", (uint64_t)i);
1461                 stack[i].Dump(&new_value);
1462                 log->Printf("  %s", new_value.GetData());
1463             }
1464             log->Printf("0x%8.8" PRIx64 ": %s", op_offset, DW_OP_value_to_name(op));
1465         }
1466         switch (op)
1467         {
1468         //----------------------------------------------------------------------
1469         // The DW_OP_addr operation has a single operand that encodes a machine
1470         // address and whose size is the size of an address on the target machine.
1471         //----------------------------------------------------------------------
1472         case DW_OP_addr:
1473             stack.push_back(Scalar(opcodes.GetAddress(&offset)));
1474             stack.back().SetValueType (Value::eValueTypeFileAddress);
1475             break;
1476 
1477         //----------------------------------------------------------------------
1478         // The DW_OP_addr_sect_offset4 is used for any location expressions in
1479         // shared libraries that have a location like:
1480         //  DW_OP_addr(0x1000)
1481         // If this address resides in a shared library, then this virtual
1482         // address won't make sense when it is evaluated in the context of a
1483         // running process where shared libraries have been slid. To account for
1484         // this, this new address type where we can store the section pointer
1485         // and a 4 byte offset.
1486         //----------------------------------------------------------------------
1487 //      case DW_OP_addr_sect_offset4:
1488 //          {
1489 //              result_type = eResultTypeFileAddress;
1490 //              lldb::Section *sect = (lldb::Section *)opcodes.GetMaxU64(&offset, sizeof(void *));
1491 //              lldb::addr_t sect_offset = opcodes.GetU32(&offset);
1492 //
1493 //              Address so_addr (sect, sect_offset);
1494 //              lldb::addr_t load_addr = so_addr.GetLoadAddress();
1495 //              if (load_addr != LLDB_INVALID_ADDRESS)
1496 //              {
1497 //                  // We successfully resolve a file address to a load
1498 //                  // address.
1499 //                  stack.push_back(load_addr);
1500 //                  break;
1501 //              }
1502 //              else
1503 //              {
1504 //                  // We were able
1505 //                  if (error_ptr)
1506 //                      error_ptr->SetErrorStringWithFormat ("Section %s in %s is not currently loaded.\n", sect->GetName().AsCString(), sect->GetModule()->GetFileSpec().GetFilename().AsCString());
1507 //                  return false;
1508 //              }
1509 //          }
1510 //          break;
1511 
1512         //----------------------------------------------------------------------
1513         // OPCODE: DW_OP_deref
1514         // OPERANDS: none
1515         // DESCRIPTION: Pops the top stack entry and treats it as an address.
1516         // The value retrieved from that address is pushed. The size of the
1517         // data retrieved from the dereferenced address is the size of an
1518         // address on the target machine.
1519         //----------------------------------------------------------------------
1520         case DW_OP_deref:
1521             {
1522                 if (stack.empty())
1523                 {
1524                     if (error_ptr)
1525                         error_ptr->SetErrorString("Expression stack empty for DW_OP_deref.");
1526                     return false;
1527                 }
1528                 Value::ValueType value_type = stack.back().GetValueType();
1529                 switch (value_type)
1530                 {
1531                 case Value::eValueTypeHostAddress:
1532                     {
1533                         void *src = (void *)stack.back().GetScalar().ULongLong();
1534                         intptr_t ptr;
1535                         ::memcpy (&ptr, src, sizeof(void *));
1536                         stack.back().GetScalar() = ptr;
1537                         stack.back().ClearContext();
1538                     }
1539                     break;
1540                 case Value::eValueTypeLoadAddress:
1541                     if (exe_ctx)
1542                     {
1543                         if (process)
1544                         {
1545                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1546                             Error error;
1547                             lldb::addr_t pointer_value = process->ReadPointerFromMemory(pointer_addr, error);
1548                             if (pointer_value != LLDB_INVALID_ADDRESS)
1549                             {
1550                                 stack.back().GetScalar() = pointer_value;
1551                                 stack.back().ClearContext();
1552                             }
1553                             else
1554                             {
1555                                 if (error_ptr)
1556                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%" PRIx64 " for DW_OP_deref: %s\n",
1557                                                                          pointer_addr,
1558                                                                          error.AsCString());
1559                                 return false;
1560                             }
1561                         }
1562                         else
1563                         {
1564                             if (error_ptr)
1565                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1566                             return false;
1567                         }
1568                     }
1569                     else
1570                     {
1571                         if (error_ptr)
1572                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1573                         return false;
1574                     }
1575                     break;
1576 
1577                 default:
1578                     break;
1579                 }
1580 
1581             }
1582             break;
1583 
1584         //----------------------------------------------------------------------
1585         // OPCODE: DW_OP_deref_size
1586         // OPERANDS: 1
1587         //  1 - uint8_t that specifies the size of the data to dereference.
1588         // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
1589         // stack entry and treats it as an address. The value retrieved from that
1590         // address is pushed. In the DW_OP_deref_size operation, however, the
1591         // size in bytes of the data retrieved from the dereferenced address is
1592         // specified by the single operand. This operand is a 1-byte unsigned
1593         // integral constant whose value may not be larger than the size of an
1594         // address on the target machine. The data retrieved is zero extended
1595         // to the size of an address on the target machine before being pushed
1596         // on the expression stack.
1597         //----------------------------------------------------------------------
1598         case DW_OP_deref_size:
1599             {
1600                 if (stack.empty())
1601                 {
1602                     if (error_ptr)
1603                         error_ptr->SetErrorString("Expression stack empty for DW_OP_deref_size.");
1604                     return false;
1605                 }
1606                 uint8_t size = opcodes.GetU8(&offset);
1607                 Value::ValueType value_type = stack.back().GetValueType();
1608                 switch (value_type)
1609                 {
1610                 case Value::eValueTypeHostAddress:
1611                     {
1612                         void *src = (void *)stack.back().GetScalar().ULongLong();
1613                         intptr_t ptr;
1614                         ::memcpy (&ptr, src, sizeof(void *));
1615                         // I can't decide whether the size operand should apply to the bytes in their
1616                         // lldb-host endianness or the target endianness.. I doubt this'll ever come up
1617                         // but I'll opt for assuming big endian regardless.
1618                         switch (size)
1619                         {
1620                             case 1: ptr = ptr & 0xff; break;
1621                             case 2: ptr = ptr & 0xffff; break;
1622                             case 3: ptr = ptr & 0xffffff; break;
1623                             case 4: ptr = ptr & 0xffffffff; break;
1624                             // the casts are added to work around the case where intptr_t is a 32 bit quantity;
1625                             // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this program.
1626                             case 5: ptr = (intptr_t) ptr & 0xffffffffffULL; break;
1627                             case 6: ptr = (intptr_t) ptr & 0xffffffffffffULL; break;
1628                             case 7: ptr = (intptr_t) ptr & 0xffffffffffffffULL; break;
1629                             default: break;
1630                         }
1631                         stack.back().GetScalar() = ptr;
1632                         stack.back().ClearContext();
1633                     }
1634                     break;
1635                 case Value::eValueTypeLoadAddress:
1636                     if (exe_ctx)
1637                     {
1638                         if (process)
1639                         {
1640                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1641                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1642                             Error error;
1643                             if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) == size)
1644                             {
1645                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), size);
1646                                 lldb::offset_t addr_data_offset = 0;
1647                                 switch (size)
1648                                 {
1649                                     case 1: stack.back().GetScalar() = addr_data.GetU8(&addr_data_offset); break;
1650                                     case 2: stack.back().GetScalar() = addr_data.GetU16(&addr_data_offset); break;
1651                                     case 4: stack.back().GetScalar() = addr_data.GetU32(&addr_data_offset); break;
1652                                     case 8: stack.back().GetScalar() = addr_data.GetU64(&addr_data_offset); break;
1653                                     default: stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1654                                 }
1655                                 stack.back().ClearContext();
1656                             }
1657                             else
1658                             {
1659                                 if (error_ptr)
1660                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%" PRIx64 " for DW_OP_deref: %s\n",
1661                                                                          pointer_addr,
1662                                                                          error.AsCString());
1663                                 return false;
1664                             }
1665                         }
1666                         else
1667                         {
1668                             if (error_ptr)
1669                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1670                             return false;
1671                         }
1672                     }
1673                     else
1674                     {
1675                         if (error_ptr)
1676                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1677                         return false;
1678                     }
1679                     break;
1680 
1681                 default:
1682                     break;
1683                 }
1684 
1685             }
1686             break;
1687 
1688         //----------------------------------------------------------------------
1689         // OPCODE: DW_OP_xderef_size
1690         // OPERANDS: 1
1691         //  1 - uint8_t that specifies the size of the data to dereference.
1692         // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
1693         // the top of the stack is treated as an address. The second stack
1694         // entry is treated as an "address space identifier" for those
1695         // architectures that support multiple address spaces. The top two
1696         // stack elements are popped, a data item is retrieved through an
1697         // implementation-defined address calculation and pushed as the new
1698         // stack top. In the DW_OP_xderef_size operation, however, the size in
1699         // bytes of the data retrieved from the dereferenced address is
1700         // specified by the single operand. This operand is a 1-byte unsigned
1701         // integral constant whose value may not be larger than the size of an
1702         // address on the target machine. The data retrieved is zero extended
1703         // to the size of an address on the target machine before being pushed
1704         // on the expression stack.
1705         //----------------------------------------------------------------------
1706         case DW_OP_xderef_size:
1707             if (error_ptr)
1708                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
1709             return false;
1710         //----------------------------------------------------------------------
1711         // OPCODE: DW_OP_xderef
1712         // OPERANDS: none
1713         // DESCRIPTION: Provides an extended dereference mechanism. The entry at
1714         // the top of the stack is treated as an address. The second stack entry
1715         // is treated as an "address space identifier" for those architectures
1716         // that support multiple address spaces. The top two stack elements are
1717         // popped, a data item is retrieved through an implementation-defined
1718         // address calculation and pushed as the new stack top. The size of the
1719         // data retrieved from the dereferenced address is the size of an address
1720         // on the target machine.
1721         //----------------------------------------------------------------------
1722         case DW_OP_xderef:
1723             if (error_ptr)
1724                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
1725             return false;
1726 
1727         //----------------------------------------------------------------------
1728         // All DW_OP_constXXX opcodes have a single operand as noted below:
1729         //
1730         // Opcode           Operand 1
1731         // ---------------  ----------------------------------------------------
1732         // DW_OP_const1u    1-byte unsigned integer constant
1733         // DW_OP_const1s    1-byte signed integer constant
1734         // DW_OP_const2u    2-byte unsigned integer constant
1735         // DW_OP_const2s    2-byte signed integer constant
1736         // DW_OP_const4u    4-byte unsigned integer constant
1737         // DW_OP_const4s    4-byte signed integer constant
1738         // DW_OP_const8u    8-byte unsigned integer constant
1739         // DW_OP_const8s    8-byte signed integer constant
1740         // DW_OP_constu     unsigned LEB128 integer constant
1741         // DW_OP_consts     signed LEB128 integer constant
1742         //----------------------------------------------------------------------
1743         case DW_OP_const1u             :    stack.push_back(Scalar(( uint8_t)opcodes.GetU8 (&offset))); break;
1744         case DW_OP_const1s             :    stack.push_back(Scalar((  int8_t)opcodes.GetU8 (&offset))); break;
1745         case DW_OP_const2u             :    stack.push_back(Scalar((uint16_t)opcodes.GetU16 (&offset))); break;
1746         case DW_OP_const2s             :    stack.push_back(Scalar(( int16_t)opcodes.GetU16 (&offset))); break;
1747         case DW_OP_const4u             :    stack.push_back(Scalar((uint32_t)opcodes.GetU32 (&offset))); break;
1748         case DW_OP_const4s             :    stack.push_back(Scalar(( int32_t)opcodes.GetU32 (&offset))); break;
1749         case DW_OP_const8u             :    stack.push_back(Scalar((uint64_t)opcodes.GetU64 (&offset))); break;
1750         case DW_OP_const8s             :    stack.push_back(Scalar(( int64_t)opcodes.GetU64 (&offset))); break;
1751         case DW_OP_constu              :    stack.push_back(Scalar(opcodes.GetULEB128 (&offset))); break;
1752         case DW_OP_consts              :    stack.push_back(Scalar(opcodes.GetSLEB128 (&offset))); break;
1753 
1754         //----------------------------------------------------------------------
1755         // OPCODE: DW_OP_dup
1756         // OPERANDS: none
1757         // DESCRIPTION: duplicates the value at the top of the stack
1758         //----------------------------------------------------------------------
1759         case DW_OP_dup:
1760             if (stack.empty())
1761             {
1762                 if (error_ptr)
1763                     error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
1764                 return false;
1765             }
1766             else
1767                 stack.push_back(stack.back());
1768             break;
1769 
1770         //----------------------------------------------------------------------
1771         // OPCODE: DW_OP_drop
1772         // OPERANDS: none
1773         // DESCRIPTION: pops the value at the top of the stack
1774         //----------------------------------------------------------------------
1775         case DW_OP_drop:
1776             if (stack.empty())
1777             {
1778                 if (error_ptr)
1779                     error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
1780                 return false;
1781             }
1782             else
1783                 stack.pop_back();
1784             break;
1785 
1786         //----------------------------------------------------------------------
1787         // OPCODE: DW_OP_over
1788         // OPERANDS: none
1789         // DESCRIPTION: Duplicates the entry currently second in the stack at
1790         // the top of the stack.
1791         //----------------------------------------------------------------------
1792         case DW_OP_over:
1793             if (stack.size() < 2)
1794             {
1795                 if (error_ptr)
1796                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_over.");
1797                 return false;
1798             }
1799             else
1800                 stack.push_back(stack[stack.size() - 2]);
1801             break;
1802 
1803 
1804         //----------------------------------------------------------------------
1805         // OPCODE: DW_OP_pick
1806         // OPERANDS: uint8_t index into the current stack
1807         // DESCRIPTION: The stack entry with the specified index (0 through 255,
1808         // inclusive) is pushed on the stack
1809         //----------------------------------------------------------------------
1810         case DW_OP_pick:
1811             {
1812                 uint8_t pick_idx = opcodes.GetU8(&offset);
1813                 if (pick_idx < stack.size())
1814                     stack.push_back(stack[pick_idx]);
1815                 else
1816                 {
1817                     if (error_ptr)
1818                         error_ptr->SetErrorStringWithFormat("Index %u out of range for DW_OP_pick.\n", pick_idx);
1819                     return false;
1820                 }
1821             }
1822             break;
1823 
1824         //----------------------------------------------------------------------
1825         // OPCODE: DW_OP_swap
1826         // OPERANDS: none
1827         // DESCRIPTION: swaps the top two stack entries. The entry at the top
1828         // of the stack becomes the second stack entry, and the second entry
1829         // becomes the top of the stack
1830         //----------------------------------------------------------------------
1831         case DW_OP_swap:
1832             if (stack.size() < 2)
1833             {
1834                 if (error_ptr)
1835                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_swap.");
1836                 return false;
1837             }
1838             else
1839             {
1840                 tmp = stack.back();
1841                 stack.back() = stack[stack.size() - 2];
1842                 stack[stack.size() - 2] = tmp;
1843             }
1844             break;
1845 
1846         //----------------------------------------------------------------------
1847         // OPCODE: DW_OP_rot
1848         // OPERANDS: none
1849         // DESCRIPTION: Rotates the first three stack entries. The entry at
1850         // the top of the stack becomes the third stack entry, the second
1851         // entry becomes the top of the stack, and the third entry becomes
1852         // the second entry.
1853         //----------------------------------------------------------------------
1854         case DW_OP_rot:
1855             if (stack.size() < 3)
1856             {
1857                 if (error_ptr)
1858                     error_ptr->SetErrorString("Expression stack needs at least 3 items for DW_OP_rot.");
1859                 return false;
1860             }
1861             else
1862             {
1863                 size_t last_idx = stack.size() - 1;
1864                 Value old_top = stack[last_idx];
1865                 stack[last_idx] = stack[last_idx - 1];
1866                 stack[last_idx - 1] = stack[last_idx - 2];
1867                 stack[last_idx - 2] = old_top;
1868             }
1869             break;
1870 
1871         //----------------------------------------------------------------------
1872         // OPCODE: DW_OP_abs
1873         // OPERANDS: none
1874         // DESCRIPTION: pops the top stack entry, interprets it as a signed
1875         // value and pushes its absolute value. If the absolute value can not be
1876         // represented, the result is undefined.
1877         //----------------------------------------------------------------------
1878         case DW_OP_abs:
1879             if (stack.empty())
1880             {
1881                 if (error_ptr)
1882                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_abs.");
1883                 return false;
1884             }
1885             else if (stack.back().ResolveValue(exe_ctx).AbsoluteValue() == false)
1886             {
1887                 if (error_ptr)
1888                     error_ptr->SetErrorString("Failed to take the absolute value of the first stack item.");
1889                 return false;
1890             }
1891             break;
1892 
1893         //----------------------------------------------------------------------
1894         // OPCODE: DW_OP_and
1895         // OPERANDS: none
1896         // DESCRIPTION: pops the top two stack values, performs a bitwise and
1897         // operation on the two, and pushes the result.
1898         //----------------------------------------------------------------------
1899         case DW_OP_and:
1900             if (stack.size() < 2)
1901             {
1902                 if (error_ptr)
1903                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_and.");
1904                 return false;
1905             }
1906             else
1907             {
1908                 tmp = stack.back();
1909                 stack.pop_back();
1910                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx);
1911             }
1912             break;
1913 
1914         //----------------------------------------------------------------------
1915         // OPCODE: DW_OP_div
1916         // OPERANDS: none
1917         // DESCRIPTION: pops the top two stack values, divides the former second
1918         // entry by the former top of the stack using signed division, and
1919         // pushes the result.
1920         //----------------------------------------------------------------------
1921         case DW_OP_div:
1922             if (stack.size() < 2)
1923             {
1924                 if (error_ptr)
1925                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_div.");
1926                 return false;
1927             }
1928             else
1929             {
1930                 tmp = stack.back();
1931                 if (tmp.ResolveValue(exe_ctx).IsZero())
1932                 {
1933                     if (error_ptr)
1934                         error_ptr->SetErrorString("Divide by zero.");
1935                     return false;
1936                 }
1937                 else
1938                 {
1939                     stack.pop_back();
1940                     stack.back() = stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx);
1941                     if (!stack.back().ResolveValue(exe_ctx).IsValid())
1942                     {
1943                         if (error_ptr)
1944                             error_ptr->SetErrorString("Divide failed.");
1945                         return false;
1946                     }
1947                 }
1948             }
1949             break;
1950 
1951         //----------------------------------------------------------------------
1952         // OPCODE: DW_OP_minus
1953         // OPERANDS: none
1954         // DESCRIPTION: pops the top two stack values, subtracts the former top
1955         // of the stack from the former second entry, and pushes the result.
1956         //----------------------------------------------------------------------
1957         case DW_OP_minus:
1958             if (stack.size() < 2)
1959             {
1960                 if (error_ptr)
1961                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_minus.");
1962                 return false;
1963             }
1964             else
1965             {
1966                 tmp = stack.back();
1967                 stack.pop_back();
1968                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx);
1969             }
1970             break;
1971 
1972         //----------------------------------------------------------------------
1973         // OPCODE: DW_OP_mod
1974         // OPERANDS: none
1975         // DESCRIPTION: pops the top two stack values and pushes the result of
1976         // the calculation: former second stack entry modulo the former top of
1977         // the stack.
1978         //----------------------------------------------------------------------
1979         case DW_OP_mod:
1980             if (stack.size() < 2)
1981             {
1982                 if (error_ptr)
1983                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mod.");
1984                 return false;
1985             }
1986             else
1987             {
1988                 tmp = stack.back();
1989                 stack.pop_back();
1990                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx);
1991             }
1992             break;
1993 
1994 
1995         //----------------------------------------------------------------------
1996         // OPCODE: DW_OP_mul
1997         // OPERANDS: none
1998         // DESCRIPTION: pops the top two stack entries, multiplies them
1999         // together, and pushes the result.
2000         //----------------------------------------------------------------------
2001         case DW_OP_mul:
2002             if (stack.size() < 2)
2003             {
2004                 if (error_ptr)
2005                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mul.");
2006                 return false;
2007             }
2008             else
2009             {
2010                 tmp = stack.back();
2011                 stack.pop_back();
2012                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) * tmp.ResolveValue(exe_ctx);
2013             }
2014             break;
2015 
2016         //----------------------------------------------------------------------
2017         // OPCODE: DW_OP_neg
2018         // OPERANDS: none
2019         // DESCRIPTION: pops the top stack entry, and pushes its negation.
2020         //----------------------------------------------------------------------
2021         case DW_OP_neg:
2022             if (stack.empty())
2023             {
2024                 if (error_ptr)
2025                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_neg.");
2026                 return false;
2027             }
2028             else
2029             {
2030                 if (stack.back().ResolveValue(exe_ctx).UnaryNegate() == false)
2031                 {
2032                     if (error_ptr)
2033                         error_ptr->SetErrorString("Unary negate failed.");
2034                     return false;
2035                 }
2036             }
2037             break;
2038 
2039         //----------------------------------------------------------------------
2040         // OPCODE: DW_OP_not
2041         // OPERANDS: none
2042         // DESCRIPTION: pops the top stack entry, and pushes its bitwise
2043         // complement
2044         //----------------------------------------------------------------------
2045         case DW_OP_not:
2046             if (stack.empty())
2047             {
2048                 if (error_ptr)
2049                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_not.");
2050                 return false;
2051             }
2052             else
2053             {
2054                 if (stack.back().ResolveValue(exe_ctx).OnesComplement() == false)
2055                 {
2056                     if (error_ptr)
2057                         error_ptr->SetErrorString("Logical NOT failed.");
2058                     return false;
2059                 }
2060             }
2061             break;
2062 
2063         //----------------------------------------------------------------------
2064         // OPCODE: DW_OP_or
2065         // OPERANDS: none
2066         // DESCRIPTION: pops the top two stack entries, performs a bitwise or
2067         // operation on the two, and pushes the result.
2068         //----------------------------------------------------------------------
2069         case DW_OP_or:
2070             if (stack.size() < 2)
2071             {
2072                 if (error_ptr)
2073                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_or.");
2074                 return false;
2075             }
2076             else
2077             {
2078                 tmp = stack.back();
2079                 stack.pop_back();
2080                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx);
2081             }
2082             break;
2083 
2084         //----------------------------------------------------------------------
2085         // OPCODE: DW_OP_plus
2086         // OPERANDS: none
2087         // DESCRIPTION: pops the top two stack entries, adds them together, and
2088         // pushes the result.
2089         //----------------------------------------------------------------------
2090         case DW_OP_plus:
2091             if (stack.size() < 2)
2092             {
2093                 if (error_ptr)
2094                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_plus.");
2095                 return false;
2096             }
2097             else
2098             {
2099                 tmp = stack.back();
2100                 stack.pop_back();
2101                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) + tmp.ResolveValue(exe_ctx);
2102             }
2103             break;
2104 
2105         //----------------------------------------------------------------------
2106         // OPCODE: DW_OP_plus_uconst
2107         // OPERANDS: none
2108         // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
2109         // constant operand and pushes the result.
2110         //----------------------------------------------------------------------
2111         case DW_OP_plus_uconst:
2112             if (stack.empty())
2113             {
2114                 if (error_ptr)
2115                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_plus_uconst.");
2116                 return false;
2117             }
2118             else
2119             {
2120                 const uint64_t uconst_value = opcodes.GetULEB128(&offset);
2121                 // Implicit conversion from a UINT to a Scalar...
2122                 stack.back().ResolveValue(exe_ctx) += uconst_value;
2123                 if (!stack.back().ResolveValue(exe_ctx).IsValid())
2124                 {
2125                     if (error_ptr)
2126                         error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
2127                     return false;
2128                 }
2129             }
2130             break;
2131 
2132         //----------------------------------------------------------------------
2133         // OPCODE: DW_OP_shl
2134         // OPERANDS: none
2135         // DESCRIPTION:  pops the top two stack entries, shifts the former
2136         // second entry left by the number of bits specified by the former top
2137         // of the stack, and pushes the result.
2138         //----------------------------------------------------------------------
2139         case DW_OP_shl:
2140             if (stack.size() < 2)
2141             {
2142                 if (error_ptr)
2143                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shl.");
2144                 return false;
2145             }
2146             else
2147             {
2148                 tmp = stack.back();
2149                 stack.pop_back();
2150                 stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx);
2151             }
2152             break;
2153 
2154         //----------------------------------------------------------------------
2155         // OPCODE: DW_OP_shr
2156         // OPERANDS: none
2157         // DESCRIPTION: pops the top two stack entries, shifts the former second
2158         // entry right logically (filling with zero bits) by the number of bits
2159         // specified by the former top of the stack, and pushes the result.
2160         //----------------------------------------------------------------------
2161         case DW_OP_shr:
2162             if (stack.size() < 2)
2163             {
2164                 if (error_ptr)
2165                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shr.");
2166                 return false;
2167             }
2168             else
2169             {
2170                 tmp = stack.back();
2171                 stack.pop_back();
2172                 if (stack.back().ResolveValue(exe_ctx).ShiftRightLogical(tmp.ResolveValue(exe_ctx)) == false)
2173                 {
2174                     if (error_ptr)
2175                         error_ptr->SetErrorString("DW_OP_shr failed.");
2176                     return false;
2177                 }
2178             }
2179             break;
2180 
2181         //----------------------------------------------------------------------
2182         // OPCODE: DW_OP_shra
2183         // OPERANDS: none
2184         // DESCRIPTION: pops the top two stack entries, shifts the former second
2185         // entry right arithmetically (divide the magnitude by 2, keep the same
2186         // sign for the result) by the number of bits specified by the former
2187         // top of the stack, and pushes the result.
2188         //----------------------------------------------------------------------
2189         case DW_OP_shra:
2190             if (stack.size() < 2)
2191             {
2192                 if (error_ptr)
2193                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shra.");
2194                 return false;
2195             }
2196             else
2197             {
2198                 tmp = stack.back();
2199                 stack.pop_back();
2200                 stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx);
2201             }
2202             break;
2203 
2204         //----------------------------------------------------------------------
2205         // OPCODE: DW_OP_xor
2206         // OPERANDS: none
2207         // DESCRIPTION: pops the top two stack entries, performs the bitwise
2208         // exclusive-or operation on the two, and pushes the result.
2209         //----------------------------------------------------------------------
2210         case DW_OP_xor:
2211             if (stack.size() < 2)
2212             {
2213                 if (error_ptr)
2214                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_xor.");
2215                 return false;
2216             }
2217             else
2218             {
2219                 tmp = stack.back();
2220                 stack.pop_back();
2221                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx);
2222             }
2223             break;
2224 
2225 
2226         //----------------------------------------------------------------------
2227         // OPCODE: DW_OP_skip
2228         // OPERANDS: int16_t
2229         // DESCRIPTION:  An unconditional branch. Its single operand is a 2-byte
2230         // signed integer constant. The 2-byte constant is the number of bytes
2231         // of the DWARF expression to skip forward or backward from the current
2232         // operation, beginning after the 2-byte constant.
2233         //----------------------------------------------------------------------
2234         case DW_OP_skip:
2235             {
2236                 int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
2237                 lldb::offset_t new_offset = offset + skip_offset;
2238                 if (new_offset >= opcodes_offset && new_offset < end_offset)
2239                     offset = new_offset;
2240                 else
2241                 {
2242                     if (error_ptr)
2243                         error_ptr->SetErrorString("Invalid opcode offset in DW_OP_skip.");
2244                     return false;
2245                 }
2246             }
2247             break;
2248 
2249         //----------------------------------------------------------------------
2250         // OPCODE: DW_OP_bra
2251         // OPERANDS: int16_t
2252         // DESCRIPTION: A conditional branch. Its single operand is a 2-byte
2253         // signed integer constant. This operation pops the top of stack. If
2254         // the value popped is not the constant 0, the 2-byte constant operand
2255         // is the number of bytes of the DWARF expression to skip forward or
2256         // backward from the current operation, beginning after the 2-byte
2257         // constant.
2258         //----------------------------------------------------------------------
2259         case DW_OP_bra:
2260             if (stack.empty())
2261             {
2262                 if (error_ptr)
2263                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_bra.");
2264                 return false;
2265             }
2266             else
2267             {
2268                 tmp = stack.back();
2269                 stack.pop_back();
2270                 int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
2271                 Scalar zero(0);
2272                 if (tmp.ResolveValue(exe_ctx) != zero)
2273                 {
2274                     lldb::offset_t new_offset = offset + bra_offset;
2275                     if (new_offset >= opcodes_offset && new_offset < end_offset)
2276                         offset = new_offset;
2277                     else
2278                     {
2279                         if (error_ptr)
2280                             error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
2281                         return false;
2282                     }
2283                 }
2284             }
2285             break;
2286 
2287         //----------------------------------------------------------------------
2288         // OPCODE: DW_OP_eq
2289         // OPERANDS: none
2290         // DESCRIPTION: pops the top two stack values, compares using the
2291         // equals (==) operator.
2292         // STACK RESULT: push the constant value 1 onto the stack if the result
2293         // of the operation is true or the constant value 0 if the result of the
2294         // operation is false.
2295         //----------------------------------------------------------------------
2296         case DW_OP_eq:
2297             if (stack.size() < 2)
2298             {
2299                 if (error_ptr)
2300                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_eq.");
2301                 return false;
2302             }
2303             else
2304             {
2305                 tmp = stack.back();
2306                 stack.pop_back();
2307                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx);
2308             }
2309             break;
2310 
2311         //----------------------------------------------------------------------
2312         // OPCODE: DW_OP_ge
2313         // OPERANDS: none
2314         // DESCRIPTION: pops the top two stack values, compares using the
2315         // greater than or equal to (>=) operator.
2316         // STACK RESULT: push the constant value 1 onto the stack if the result
2317         // of the operation is true or the constant value 0 if the result of the
2318         // operation is false.
2319         //----------------------------------------------------------------------
2320         case DW_OP_ge:
2321             if (stack.size() < 2)
2322             {
2323                 if (error_ptr)
2324                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ge.");
2325                 return false;
2326             }
2327             else
2328             {
2329                 tmp = stack.back();
2330                 stack.pop_back();
2331                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx);
2332             }
2333             break;
2334 
2335         //----------------------------------------------------------------------
2336         // OPCODE: DW_OP_gt
2337         // OPERANDS: none
2338         // DESCRIPTION: pops the top two stack values, compares using the
2339         // greater than (>) operator.
2340         // STACK RESULT: push the constant value 1 onto the stack if the result
2341         // of the operation is true or the constant value 0 if the result of the
2342         // operation is false.
2343         //----------------------------------------------------------------------
2344         case DW_OP_gt:
2345             if (stack.size() < 2)
2346             {
2347                 if (error_ptr)
2348                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_gt.");
2349                 return false;
2350             }
2351             else
2352             {
2353                 tmp = stack.back();
2354                 stack.pop_back();
2355                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx);
2356             }
2357             break;
2358 
2359         //----------------------------------------------------------------------
2360         // OPCODE: DW_OP_le
2361         // OPERANDS: none
2362         // DESCRIPTION: pops the top two stack values, compares using the
2363         // less than or equal to (<=) operator.
2364         // STACK RESULT: push the constant value 1 onto the stack if the result
2365         // of the operation is true or the constant value 0 if the result of the
2366         // operation is false.
2367         //----------------------------------------------------------------------
2368         case DW_OP_le:
2369             if (stack.size() < 2)
2370             {
2371                 if (error_ptr)
2372                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_le.");
2373                 return false;
2374             }
2375             else
2376             {
2377                 tmp = stack.back();
2378                 stack.pop_back();
2379                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx);
2380             }
2381             break;
2382 
2383         //----------------------------------------------------------------------
2384         // OPCODE: DW_OP_lt
2385         // OPERANDS: none
2386         // DESCRIPTION: pops the top two stack values, compares using the
2387         // less than (<) operator.
2388         // STACK RESULT: push the constant value 1 onto the stack if the result
2389         // of the operation is true or the constant value 0 if the result of the
2390         // operation is false.
2391         //----------------------------------------------------------------------
2392         case DW_OP_lt:
2393             if (stack.size() < 2)
2394             {
2395                 if (error_ptr)
2396                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_lt.");
2397                 return false;
2398             }
2399             else
2400             {
2401                 tmp = stack.back();
2402                 stack.pop_back();
2403                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) < tmp.ResolveValue(exe_ctx);
2404             }
2405             break;
2406 
2407         //----------------------------------------------------------------------
2408         // OPCODE: DW_OP_ne
2409         // OPERANDS: none
2410         // DESCRIPTION: pops the top two stack values, compares using the
2411         // not equal (!=) operator.
2412         // STACK RESULT: push the constant value 1 onto the stack if the result
2413         // of the operation is true or the constant value 0 if the result of the
2414         // operation is false.
2415         //----------------------------------------------------------------------
2416         case DW_OP_ne:
2417             if (stack.size() < 2)
2418             {
2419                 if (error_ptr)
2420                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ne.");
2421                 return false;
2422             }
2423             else
2424             {
2425                 tmp = stack.back();
2426                 stack.pop_back();
2427                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) != tmp.ResolveValue(exe_ctx);
2428             }
2429             break;
2430 
2431         //----------------------------------------------------------------------
2432         // OPCODE: DW_OP_litn
2433         // OPERANDS: none
2434         // DESCRIPTION: encode the unsigned literal values from 0 through 31.
2435         // STACK RESULT: push the unsigned literal constant value onto the top
2436         // of the stack.
2437         //----------------------------------------------------------------------
2438         case DW_OP_lit0:
2439         case DW_OP_lit1:
2440         case DW_OP_lit2:
2441         case DW_OP_lit3:
2442         case DW_OP_lit4:
2443         case DW_OP_lit5:
2444         case DW_OP_lit6:
2445         case DW_OP_lit7:
2446         case DW_OP_lit8:
2447         case DW_OP_lit9:
2448         case DW_OP_lit10:
2449         case DW_OP_lit11:
2450         case DW_OP_lit12:
2451         case DW_OP_lit13:
2452         case DW_OP_lit14:
2453         case DW_OP_lit15:
2454         case DW_OP_lit16:
2455         case DW_OP_lit17:
2456         case DW_OP_lit18:
2457         case DW_OP_lit19:
2458         case DW_OP_lit20:
2459         case DW_OP_lit21:
2460         case DW_OP_lit22:
2461         case DW_OP_lit23:
2462         case DW_OP_lit24:
2463         case DW_OP_lit25:
2464         case DW_OP_lit26:
2465         case DW_OP_lit27:
2466         case DW_OP_lit28:
2467         case DW_OP_lit29:
2468         case DW_OP_lit30:
2469         case DW_OP_lit31:
2470             stack.push_back(Scalar(op - DW_OP_lit0));
2471             break;
2472 
2473         //----------------------------------------------------------------------
2474         // OPCODE: DW_OP_regN
2475         // OPERANDS: none
2476         // DESCRIPTION: Push the value in register n on the top of the stack.
2477         //----------------------------------------------------------------------
2478         case DW_OP_reg0:
2479         case DW_OP_reg1:
2480         case DW_OP_reg2:
2481         case DW_OP_reg3:
2482         case DW_OP_reg4:
2483         case DW_OP_reg5:
2484         case DW_OP_reg6:
2485         case DW_OP_reg7:
2486         case DW_OP_reg8:
2487         case DW_OP_reg9:
2488         case DW_OP_reg10:
2489         case DW_OP_reg11:
2490         case DW_OP_reg12:
2491         case DW_OP_reg13:
2492         case DW_OP_reg14:
2493         case DW_OP_reg15:
2494         case DW_OP_reg16:
2495         case DW_OP_reg17:
2496         case DW_OP_reg18:
2497         case DW_OP_reg19:
2498         case DW_OP_reg20:
2499         case DW_OP_reg21:
2500         case DW_OP_reg22:
2501         case DW_OP_reg23:
2502         case DW_OP_reg24:
2503         case DW_OP_reg25:
2504         case DW_OP_reg26:
2505         case DW_OP_reg27:
2506         case DW_OP_reg28:
2507         case DW_OP_reg29:
2508         case DW_OP_reg30:
2509         case DW_OP_reg31:
2510             {
2511                 reg_num = op - DW_OP_reg0;
2512 
2513                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2514                     stack.push_back(tmp);
2515                 else
2516                     return false;
2517             }
2518             break;
2519         //----------------------------------------------------------------------
2520         // OPCODE: DW_OP_regx
2521         // OPERANDS:
2522         //      ULEB128 literal operand that encodes the register.
2523         // DESCRIPTION: Push the value in register on the top of the stack.
2524         //----------------------------------------------------------------------
2525         case DW_OP_regx:
2526             {
2527                 reg_num = opcodes.GetULEB128(&offset);
2528                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2529                     stack.push_back(tmp);
2530                 else
2531                     return false;
2532             }
2533             break;
2534 
2535         //----------------------------------------------------------------------
2536         // OPCODE: DW_OP_bregN
2537         // OPERANDS:
2538         //      SLEB128 offset from register N
2539         // DESCRIPTION: Value is in memory at the address specified by register
2540         // N plus an offset.
2541         //----------------------------------------------------------------------
2542         case DW_OP_breg0:
2543         case DW_OP_breg1:
2544         case DW_OP_breg2:
2545         case DW_OP_breg3:
2546         case DW_OP_breg4:
2547         case DW_OP_breg5:
2548         case DW_OP_breg6:
2549         case DW_OP_breg7:
2550         case DW_OP_breg8:
2551         case DW_OP_breg9:
2552         case DW_OP_breg10:
2553         case DW_OP_breg11:
2554         case DW_OP_breg12:
2555         case DW_OP_breg13:
2556         case DW_OP_breg14:
2557         case DW_OP_breg15:
2558         case DW_OP_breg16:
2559         case DW_OP_breg17:
2560         case DW_OP_breg18:
2561         case DW_OP_breg19:
2562         case DW_OP_breg20:
2563         case DW_OP_breg21:
2564         case DW_OP_breg22:
2565         case DW_OP_breg23:
2566         case DW_OP_breg24:
2567         case DW_OP_breg25:
2568         case DW_OP_breg26:
2569         case DW_OP_breg27:
2570         case DW_OP_breg28:
2571         case DW_OP_breg29:
2572         case DW_OP_breg30:
2573         case DW_OP_breg31:
2574             {
2575                 reg_num = op - DW_OP_breg0;
2576 
2577                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2578                 {
2579                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2580                     tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
2581                     tmp.ClearContext();
2582                     stack.push_back(tmp);
2583                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2584                 }
2585                 else
2586                     return false;
2587             }
2588             break;
2589         //----------------------------------------------------------------------
2590         // OPCODE: DW_OP_bregx
2591         // OPERANDS: 2
2592         //      ULEB128 literal operand that encodes the register.
2593         //      SLEB128 offset from register N
2594         // DESCRIPTION: Value is in memory at the address specified by register
2595         // N plus an offset.
2596         //----------------------------------------------------------------------
2597         case DW_OP_bregx:
2598             {
2599                 reg_num = opcodes.GetULEB128(&offset);
2600 
2601                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2602                 {
2603                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2604                     tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
2605                     tmp.ClearContext();
2606                     stack.push_back(tmp);
2607                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2608                 }
2609                 else
2610                     return false;
2611             }
2612             break;
2613 
2614         case DW_OP_fbreg:
2615             if (exe_ctx)
2616             {
2617                 if (frame)
2618                 {
2619                     Scalar value;
2620                     if (frame->GetFrameBaseValue(value, error_ptr))
2621                     {
2622                         int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
2623                         value += fbreg_offset;
2624                         stack.push_back(value);
2625                         stack.back().SetValueType (Value::eValueTypeLoadAddress);
2626                     }
2627                     else
2628                         return false;
2629                 }
2630                 else
2631                 {
2632                     if (error_ptr)
2633                         error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_fbreg opcode.");
2634                     return false;
2635                 }
2636             }
2637             else
2638             {
2639                 if (error_ptr)
2640                     error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_fbreg.\n");
2641                 return false;
2642             }
2643 
2644             break;
2645 
2646         //----------------------------------------------------------------------
2647         // OPCODE: DW_OP_nop
2648         // OPERANDS: none
2649         // DESCRIPTION: A place holder. It has no effect on the location stack
2650         // or any of its values.
2651         //----------------------------------------------------------------------
2652         case DW_OP_nop:
2653             break;
2654 
2655         //----------------------------------------------------------------------
2656         // OPCODE: DW_OP_piece
2657         // OPERANDS: 1
2658         //      ULEB128: byte size of the piece
2659         // DESCRIPTION: The operand describes the size in bytes of the piece of
2660         // the object referenced by the DWARF expression whose result is at the
2661         // top of the stack. If the piece is located in a register, but does not
2662         // occupy the entire register, the placement of the piece within that
2663         // register is defined by the ABI.
2664         //
2665         // Many compilers store a single variable in sets of registers, or store
2666         // a variable partially in memory and partially in registers.
2667         // DW_OP_piece provides a way of describing how large a part of a
2668         // variable a particular DWARF expression refers to.
2669         //----------------------------------------------------------------------
2670         case DW_OP_piece:
2671             {
2672                 const uint64_t piece_byte_size = opcodes.GetULEB128(&offset);
2673 
2674                 if (piece_byte_size > 0)
2675                 {
2676                     Value curr_piece;
2677 
2678                     if (stack.empty())
2679                     {
2680                         // In a multi-piece expression, this means that the current piece is not available.
2681                         // Fill with zeros for now by resizing the data and appending it
2682                         curr_piece.ResizeData(piece_byte_size);
2683                         ::memset (curr_piece.GetBuffer().GetBytes(), 0, piece_byte_size);
2684                         pieces.AppendDataToHostBuffer(curr_piece);
2685                     }
2686                     else
2687                     {
2688                         Error error;
2689                         // Extract the current piece into "curr_piece"
2690                         Value curr_piece_source_value(stack.back());
2691                         stack.pop_back();
2692 
2693                         const Value::ValueType curr_piece_source_value_type = curr_piece_source_value.GetValueType();
2694                         switch (curr_piece_source_value_type)
2695                         {
2696                         case Value::eValueTypeLoadAddress:
2697                             if (process)
2698                             {
2699                                 if (curr_piece.ResizeData(piece_byte_size) == piece_byte_size)
2700                                 {
2701                                     lldb::addr_t load_addr = curr_piece_source_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
2702                                     if (process->ReadMemory(load_addr, curr_piece.GetBuffer().GetBytes(), piece_byte_size, error) != piece_byte_size)
2703                                     {
2704                                         if (error_ptr)
2705                                             error_ptr->SetErrorStringWithFormat ("failed to read memory DW_OP_piece(%" PRIu64 ") from 0x%" PRIx64,
2706                                                                                  piece_byte_size,
2707                                                                                  load_addr);
2708                                         return false;
2709                                     }
2710                                 }
2711                                 else
2712                                 {
2713                                     if (error_ptr)
2714                                         error_ptr->SetErrorStringWithFormat ("failed to resize the piece memory buffer for DW_OP_piece(%" PRIu64 ")", piece_byte_size);
2715                                     return false;
2716                                 }
2717                             }
2718                             break;
2719 
2720                         case Value::eValueTypeFileAddress:
2721                         case Value::eValueTypeHostAddress:
2722                             if (error_ptr)
2723                             {
2724                                 lldb::addr_t addr = curr_piece_source_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
2725                                 error_ptr->SetErrorStringWithFormat ("failed to read memory DW_OP_piece(%" PRIu64 ") from %s address 0x%" PRIx64,
2726                                                                      piece_byte_size,
2727                                                                      curr_piece_source_value.GetValueType() == Value::eValueTypeFileAddress ? "file" : "host",
2728                                                                      addr);
2729                             }
2730                             return false;
2731 
2732                         case Value::eValueTypeScalar:
2733                             {
2734                                 uint32_t bit_size = piece_byte_size * 8;
2735                                 uint32_t bit_offset = 0;
2736                                 if (!curr_piece_source_value.GetScalar().ExtractBitfield (bit_size, bit_offset))
2737                                 {
2738                                     if (error_ptr)
2739                                         error_ptr->SetErrorStringWithFormat("unable to extract %" PRIu64 " bytes from a %" PRIu64 " byte scalar value.", piece_byte_size, (uint64_t)curr_piece_source_value.GetScalar().GetByteSize());
2740                                     return false;
2741                                 }
2742                                 curr_piece = curr_piece_source_value;
2743                             }
2744                             break;
2745 
2746                         case Value::eValueTypeVector:
2747                             {
2748                                 if (curr_piece_source_value.GetVector().length >= piece_byte_size)
2749                                     curr_piece_source_value.GetVector().length = piece_byte_size;
2750                                 else
2751                                 {
2752                                     if (error_ptr)
2753                                         error_ptr->SetErrorStringWithFormat("unable to extract %" PRIu64 " bytes from a %" PRIu64 " byte vector value.", piece_byte_size, (uint64_t)curr_piece_source_value.GetVector().length);
2754                                     return false;
2755                                 }
2756                             }
2757                             break;
2758 
2759                         }
2760 
2761                         // Check if this is the first piece?
2762                         if (op_piece_offset == 0)
2763                         {
2764                             // This is the first piece, we should push it back onto the stack so subsequent
2765                             // pieces will be able to access this piece and add to it
2766                             if (pieces.AppendDataToHostBuffer(curr_piece) == 0)
2767                             {
2768                                 if (error_ptr)
2769                                     error_ptr->SetErrorString("failed to append piece data");
2770                                 return false;
2771                             }
2772                         }
2773                         else
2774                         {
2775                             // If this is the second or later piece there should be a value on the stack
2776                             if (pieces.GetBuffer().GetByteSize() != op_piece_offset)
2777                             {
2778                                 if (error_ptr)
2779                                     error_ptr->SetErrorStringWithFormat ("DW_OP_piece for offset %" PRIu64 " but top of stack is of size %" PRIu64,
2780                                                                          op_piece_offset,
2781                                                                          pieces.GetBuffer().GetByteSize());
2782                                 return false;
2783                             }
2784 
2785                             if (pieces.AppendDataToHostBuffer(curr_piece) == 0)
2786                             {
2787                                 if (error_ptr)
2788                                     error_ptr->SetErrorString("failed to append piece data");
2789                                 return false;
2790                             }
2791                         }
2792                         op_piece_offset += piece_byte_size;
2793                     }
2794                 }
2795             }
2796             break;
2797 
2798         case DW_OP_bit_piece:   // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
2799             if (stack.size() < 1)
2800             {
2801                 if (error_ptr)
2802                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_bit_piece.");
2803                 return false;
2804             }
2805             else
2806             {
2807                 const uint64_t piece_bit_size = opcodes.GetULEB128(&offset);
2808                 const uint64_t piece_bit_offset = opcodes.GetULEB128(&offset);
2809                 switch (stack.back().GetValueType())
2810                 {
2811                 case Value::eValueTypeScalar:
2812                     {
2813                         if (!stack.back().GetScalar().ExtractBitfield (piece_bit_size, piece_bit_offset))
2814                         {
2815                             if (error_ptr)
2816                                 error_ptr->SetErrorStringWithFormat("unable to extract %" PRIu64 " bit value with %" PRIu64 " bit offset from a %" PRIu64 " bit scalar value.",
2817                                                                     piece_bit_size,
2818                                                                     piece_bit_offset,
2819                                                                     (uint64_t)(stack.back().GetScalar().GetByteSize()*8));
2820                             return false;
2821                         }
2822                     }
2823                     break;
2824 
2825                 case Value::eValueTypeFileAddress:
2826                 case Value::eValueTypeLoadAddress:
2827                 case Value::eValueTypeHostAddress:
2828                     if (error_ptr)
2829                     {
2830                         error_ptr->SetErrorStringWithFormat ("unable to extract DW_OP_bit_piece(bit_size = %" PRIu64 ", bit_offset = %" PRIu64 ") from an addresss value.",
2831                                                              piece_bit_size,
2832                                                              piece_bit_offset);
2833                     }
2834                     return false;
2835 
2836                 case Value::eValueTypeVector:
2837                     if (error_ptr)
2838                     {
2839                         error_ptr->SetErrorStringWithFormat ("unable to extract DW_OP_bit_piece(bit_size = %" PRIu64 ", bit_offset = %" PRIu64 ") from a vector value.",
2840                                                              piece_bit_size,
2841                                                              piece_bit_offset);
2842                     }
2843                     return false;
2844                 }
2845             }
2846             break;
2847 
2848         //----------------------------------------------------------------------
2849         // OPCODE: DW_OP_push_object_address
2850         // OPERANDS: none
2851         // DESCRIPTION: Pushes the address of the object currently being
2852         // evaluated as part of evaluation of a user presented expression.
2853         // This object may correspond to an independent variable described by
2854         // its own DIE or it may be a component of an array, structure, or class
2855         // whose address has been dynamically determined by an earlier step
2856         // during user expression evaluation.
2857         //----------------------------------------------------------------------
2858         case DW_OP_push_object_address:
2859             if (error_ptr)
2860                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_push_object_address.");
2861             return false;
2862 
2863         //----------------------------------------------------------------------
2864         // OPCODE: DW_OP_call2
2865         // OPERANDS:
2866         //      uint16_t compile unit relative offset of a DIE
2867         // DESCRIPTION: Performs subroutine calls during evaluation
2868         // of a DWARF expression. The operand is the 2-byte unsigned offset
2869         // of a debugging information entry in the current compilation unit.
2870         //
2871         // Operand interpretation is exactly like that for DW_FORM_ref2.
2872         //
2873         // This operation transfers control of DWARF expression evaluation
2874         // to the DW_AT_location attribute of the referenced DIE. If there is
2875         // no such attribute, then there is no effect. Execution of the DWARF
2876         // expression of a DW_AT_location attribute may add to and/or remove from
2877         // values on the stack. Execution returns to the point following the call
2878         // when the end of the attribute is reached. Values on the stack at the
2879         // time of the call may be used as parameters by the called expression
2880         // and values left on the stack by the called expression may be used as
2881         // return values by prior agreement between the calling and called
2882         // expressions.
2883         //----------------------------------------------------------------------
2884         case DW_OP_call2:
2885             if (error_ptr)
2886                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call2.");
2887             return false;
2888         //----------------------------------------------------------------------
2889         // OPCODE: DW_OP_call4
2890         // OPERANDS: 1
2891         //      uint32_t compile unit relative offset of a DIE
2892         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2893         // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset
2894         // of a debugging information entry in  the current compilation unit.
2895         //
2896         // Operand interpretation DW_OP_call4 is exactly like that for
2897         // DW_FORM_ref4.
2898         //
2899         // This operation transfers control of DWARF expression evaluation
2900         // to the DW_AT_location attribute of the referenced DIE. If there is
2901         // no such attribute, then there is no effect. Execution of the DWARF
2902         // expression of a DW_AT_location attribute may add to and/or remove from
2903         // values on the stack. Execution returns to the point following the call
2904         // when the end of the attribute is reached. Values on the stack at the
2905         // time of the call may be used as parameters by the called expression
2906         // and values left on the stack by the called expression may be used as
2907         // return values by prior agreement between the calling and called
2908         // expressions.
2909         //----------------------------------------------------------------------
2910         case DW_OP_call4:
2911             if (error_ptr)
2912                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call4.");
2913             return false;
2914 
2915         //----------------------------------------------------------------------
2916         // OPCODE: DW_OP_stack_value
2917         // OPERANDS: None
2918         // DESCRIPTION: Specifies that the object does not exist in memory but
2919         // rather is a constant value.  The value from the top of the stack is
2920         // the value to be used.  This is the actual object value and not the
2921         // location.
2922         //----------------------------------------------------------------------
2923         case DW_OP_stack_value:
2924             stack.back().SetValueType(Value::eValueTypeScalar);
2925             break;
2926 
2927         //----------------------------------------------------------------------
2928         // OPCODE: DW_OP_call_frame_cfa
2929         // OPERANDS: None
2930         // DESCRIPTION: Specifies a DWARF expression that pushes the value of
2931         // the canonical frame address consistent with the call frame information
2932         // located in .debug_frame (or in the FDEs of the eh_frame section).
2933         //----------------------------------------------------------------------
2934         case DW_OP_call_frame_cfa:
2935             if (frame)
2936             {
2937                 // Note that we don't have to parse FDEs because this DWARF expression
2938                 // is commonly evaluated with a valid stack frame.
2939                 StackID id = frame->GetStackID();
2940                 addr_t cfa = id.GetCallFrameAddress();
2941                 if (cfa != LLDB_INVALID_ADDRESS)
2942                 {
2943                     stack.push_back(Scalar(cfa));
2944                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2945                 }
2946                 else
2947                     if (error_ptr)
2948                         error_ptr->SetErrorString ("Stack frame does not include a canonical frame address for DW_OP_call_frame_cfa opcode.");
2949             }
2950             else
2951             {
2952                 if (error_ptr)
2953                     error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_call_frame_cfa opcode.");
2954                 return false;
2955             }
2956             break;
2957 
2958         //----------------------------------------------------------------------
2959         // OPCODE: DW_OP_form_tls_address (or the old pre-DWARFv3 vendor extension opcode, DW_OP_GNU_push_tls_address)
2960         // OPERANDS: none
2961         // DESCRIPTION: Pops a TLS offset from the stack, converts it to
2962         // an address in the current thread's thread-local storage block,
2963         // and pushes it on the stack.
2964         //----------------------------------------------------------------------
2965         case DW_OP_form_tls_address:
2966         case DW_OP_GNU_push_tls_address:
2967             {
2968                 if (stack.size() < 1)
2969                 {
2970                     if (error_ptr)
2971                     {
2972                         if (op == DW_OP_form_tls_address)
2973                             error_ptr->SetErrorString("DW_OP_form_tls_address needs an argument.");
2974                         else
2975                             error_ptr->SetErrorString("DW_OP_GNU_push_tls_address needs an argument.");
2976                     }
2977                     return false;
2978                 }
2979 
2980                 if (!exe_ctx || !module_sp)
2981                 {
2982                     if (error_ptr)
2983                         error_ptr->SetErrorString("No context to evaluate TLS within.");
2984                     return false;
2985                 }
2986 
2987                 Thread *thread = exe_ctx->GetThreadPtr();
2988                 if (!thread)
2989                 {
2990                     if (error_ptr)
2991                         error_ptr->SetErrorString("No thread to evaluate TLS within.");
2992                     return false;
2993                 }
2994 
2995                 // Lookup the TLS block address for this thread and module.
2996                 addr_t tls_addr = thread->GetThreadLocalData (module_sp);
2997 
2998                 if (tls_addr == LLDB_INVALID_ADDRESS)
2999                 {
3000                     if (error_ptr)
3001                         error_ptr->SetErrorString ("No TLS data currently exists for this thread.");
3002                     return false;
3003                 }
3004 
3005                 // Convert the TLS offset into the absolute address.
3006                 Scalar tmp = stack.back().ResolveValue(exe_ctx);
3007                 stack.back() = tmp + tls_addr;
3008                 stack.back().SetValueType (Value::eValueTypeLoadAddress);
3009             }
3010             break;
3011 
3012         //----------------------------------------------------------------------
3013         // OPCODE: DW_OP_GNU_addr_index
3014         // OPERANDS: 1
3015         //      ULEB128: index to the .debug_addr section
3016         // DESCRIPTION: Pushes an address to the stack from the .debug_addr
3017         // section with the base address specified by the DW_AT_addr_base
3018         // attribute and the 0 based index is the ULEB128 encoded index.
3019         //----------------------------------------------------------------------
3020         case DW_OP_GNU_addr_index:
3021             {
3022                 if (!dwarf_cu)
3023                 {
3024                     if (error_ptr)
3025                         error_ptr->SetErrorString ("DW_OP_GNU_addr_index found without a compile being specified");
3026                     return false;
3027                 }
3028                 uint64_t index = opcodes.GetULEB128(&offset);
3029                 uint32_t index_size = dwarf_cu->GetAddressByteSize();
3030                 dw_offset_t addr_base = dwarf_cu->GetAddrBase();
3031                 lldb::offset_t offset = addr_base + index * index_size;
3032                 uint64_t value = dwarf_cu->GetSymbolFileDWARF()->get_debug_addr_data().GetMaxU64(&offset, index_size);
3033                 stack.push_back(Scalar(value));
3034                 stack.back().SetValueType(Value::eValueTypeFileAddress);
3035             }
3036             break;
3037 
3038         default:
3039             if (log)
3040                 log->Printf("Unhandled opcode %s in DWARFExpression.", DW_OP_value_to_name(op));
3041             break;
3042         }
3043     }
3044 
3045     if (stack.empty())
3046     {
3047         // Nothing on the stack, check if we created a piece value from DW_OP_piece or DW_OP_bit_piece opcodes
3048         if (pieces.GetBuffer().GetByteSize())
3049         {
3050             result = pieces;
3051         }
3052         else
3053         {
3054             if (error_ptr)
3055                 error_ptr->SetErrorString ("Stack empty after evaluation.");
3056             return false;
3057         }
3058     }
3059     else
3060     {
3061         if (log && log->GetVerbose())
3062         {
3063             size_t count = stack.size();
3064             log->Printf("Stack after operation has %" PRIu64 " values:", (uint64_t)count);
3065             for (size_t i=0; i<count; ++i)
3066             {
3067                 StreamString new_value;
3068                 new_value.Printf("[%" PRIu64 "]", (uint64_t)i);
3069                 stack[i].Dump(&new_value);
3070                 log->Printf("  %s", new_value.GetData());
3071             }
3072         }
3073         result = stack.back();
3074     }
3075     return true;    // Return true on success
3076 }
3077 
3078