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