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 #include <vector>
13 
14 #include "lldb/Core/DataEncoder.h"
15 #include "lldb/Core/dwarf.h"
16 #include "lldb/Core/Log.h"
17 #include "lldb/Core/RegisterValue.h"
18 #include "lldb/Core/StreamString.h"
19 #include "lldb/Core/Scalar.h"
20 #include "lldb/Core/Value.h"
21 #include "lldb/Core/VMRange.h"
22 
23 #include "lldb/Expression/ClangExpressionDeclMap.h"
24 #include "lldb/Expression/ClangExpressionVariable.h"
25 
26 #include "lldb/Host/Endian.h"
27 #include "lldb/Host/Host.h"
28 
29 #include "lldb/lldb-private-log.h"
30 
31 #include "lldb/Symbol/ClangASTType.h"
32 #include "lldb/Symbol/ClangASTContext.h"
33 #include "lldb/Symbol/Type.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 
41 using namespace lldb;
42 using namespace lldb_private;
43 
44 const char *
45 DW_OP_value_to_name (uint32_t val)
46 {
47   static char invalid[100];
48   switch (val) {
49     case 0x03: return "DW_OP_addr";
50     case 0x06: return "DW_OP_deref";
51     case 0x08: return "DW_OP_const1u";
52     case 0x09: return "DW_OP_const1s";
53     case 0x0a: return "DW_OP_const2u";
54     case 0x0b: return "DW_OP_const2s";
55     case 0x0c: return "DW_OP_const4u";
56     case 0x0d: return "DW_OP_const4s";
57     case 0x0e: return "DW_OP_const8u";
58     case 0x0f: return "DW_OP_const8s";
59     case 0x10: return "DW_OP_constu";
60     case 0x11: return "DW_OP_consts";
61     case 0x12: return "DW_OP_dup";
62     case 0x13: return "DW_OP_drop";
63     case 0x14: return "DW_OP_over";
64     case 0x15: return "DW_OP_pick";
65     case 0x16: return "DW_OP_swap";
66     case 0x17: return "DW_OP_rot";
67     case 0x18: return "DW_OP_xderef";
68     case 0x19: return "DW_OP_abs";
69     case 0x1a: return "DW_OP_and";
70     case 0x1b: return "DW_OP_div";
71     case 0x1c: return "DW_OP_minus";
72     case 0x1d: return "DW_OP_mod";
73     case 0x1e: return "DW_OP_mul";
74     case 0x1f: return "DW_OP_neg";
75     case 0x20: return "DW_OP_not";
76     case 0x21: return "DW_OP_or";
77     case 0x22: return "DW_OP_plus";
78     case 0x23: return "DW_OP_plus_uconst";
79     case 0x24: return "DW_OP_shl";
80     case 0x25: return "DW_OP_shr";
81     case 0x26: return "DW_OP_shra";
82     case 0x27: return "DW_OP_xor";
83     case 0x2f: return "DW_OP_skip";
84     case 0x28: return "DW_OP_bra";
85     case 0x29: return "DW_OP_eq";
86     case 0x2a: return "DW_OP_ge";
87     case 0x2b: return "DW_OP_gt";
88     case 0x2c: return "DW_OP_le";
89     case 0x2d: return "DW_OP_lt";
90     case 0x2e: return "DW_OP_ne";
91     case 0x30: return "DW_OP_lit0";
92     case 0x31: return "DW_OP_lit1";
93     case 0x32: return "DW_OP_lit2";
94     case 0x33: return "DW_OP_lit3";
95     case 0x34: return "DW_OP_lit4";
96     case 0x35: return "DW_OP_lit5";
97     case 0x36: return "DW_OP_lit6";
98     case 0x37: return "DW_OP_lit7";
99     case 0x38: return "DW_OP_lit8";
100     case 0x39: return "DW_OP_lit9";
101     case 0x3a: return "DW_OP_lit10";
102     case 0x3b: return "DW_OP_lit11";
103     case 0x3c: return "DW_OP_lit12";
104     case 0x3d: return "DW_OP_lit13";
105     case 0x3e: return "DW_OP_lit14";
106     case 0x3f: return "DW_OP_lit15";
107     case 0x40: return "DW_OP_lit16";
108     case 0x41: return "DW_OP_lit17";
109     case 0x42: return "DW_OP_lit18";
110     case 0x43: return "DW_OP_lit19";
111     case 0x44: return "DW_OP_lit20";
112     case 0x45: return "DW_OP_lit21";
113     case 0x46: return "DW_OP_lit22";
114     case 0x47: return "DW_OP_lit23";
115     case 0x48: return "DW_OP_lit24";
116     case 0x49: return "DW_OP_lit25";
117     case 0x4a: return "DW_OP_lit26";
118     case 0x4b: return "DW_OP_lit27";
119     case 0x4c: return "DW_OP_lit28";
120     case 0x4d: return "DW_OP_lit29";
121     case 0x4e: return "DW_OP_lit30";
122     case 0x4f: return "DW_OP_lit31";
123     case 0x50: return "DW_OP_reg0";
124     case 0x51: return "DW_OP_reg1";
125     case 0x52: return "DW_OP_reg2";
126     case 0x53: return "DW_OP_reg3";
127     case 0x54: return "DW_OP_reg4";
128     case 0x55: return "DW_OP_reg5";
129     case 0x56: return "DW_OP_reg6";
130     case 0x57: return "DW_OP_reg7";
131     case 0x58: return "DW_OP_reg8";
132     case 0x59: return "DW_OP_reg9";
133     case 0x5a: return "DW_OP_reg10";
134     case 0x5b: return "DW_OP_reg11";
135     case 0x5c: return "DW_OP_reg12";
136     case 0x5d: return "DW_OP_reg13";
137     case 0x5e: return "DW_OP_reg14";
138     case 0x5f: return "DW_OP_reg15";
139     case 0x60: return "DW_OP_reg16";
140     case 0x61: return "DW_OP_reg17";
141     case 0x62: return "DW_OP_reg18";
142     case 0x63: return "DW_OP_reg19";
143     case 0x64: return "DW_OP_reg20";
144     case 0x65: return "DW_OP_reg21";
145     case 0x66: return "DW_OP_reg22";
146     case 0x67: return "DW_OP_reg23";
147     case 0x68: return "DW_OP_reg24";
148     case 0x69: return "DW_OP_reg25";
149     case 0x6a: return "DW_OP_reg26";
150     case 0x6b: return "DW_OP_reg27";
151     case 0x6c: return "DW_OP_reg28";
152     case 0x6d: return "DW_OP_reg29";
153     case 0x6e: return "DW_OP_reg30";
154     case 0x6f: return "DW_OP_reg31";
155     case 0x70: return "DW_OP_breg0";
156     case 0x71: return "DW_OP_breg1";
157     case 0x72: return "DW_OP_breg2";
158     case 0x73: return "DW_OP_breg3";
159     case 0x74: return "DW_OP_breg4";
160     case 0x75: return "DW_OP_breg5";
161     case 0x76: return "DW_OP_breg6";
162     case 0x77: return "DW_OP_breg7";
163     case 0x78: return "DW_OP_breg8";
164     case 0x79: return "DW_OP_breg9";
165     case 0x7a: return "DW_OP_breg10";
166     case 0x7b: return "DW_OP_breg11";
167     case 0x7c: return "DW_OP_breg12";
168     case 0x7d: return "DW_OP_breg13";
169     case 0x7e: return "DW_OP_breg14";
170     case 0x7f: return "DW_OP_breg15";
171     case 0x80: return "DW_OP_breg16";
172     case 0x81: return "DW_OP_breg17";
173     case 0x82: return "DW_OP_breg18";
174     case 0x83: return "DW_OP_breg19";
175     case 0x84: return "DW_OP_breg20";
176     case 0x85: return "DW_OP_breg21";
177     case 0x86: return "DW_OP_breg22";
178     case 0x87: return "DW_OP_breg23";
179     case 0x88: return "DW_OP_breg24";
180     case 0x89: return "DW_OP_breg25";
181     case 0x8a: return "DW_OP_breg26";
182     case 0x8b: return "DW_OP_breg27";
183     case 0x8c: return "DW_OP_breg28";
184     case 0x8d: return "DW_OP_breg29";
185     case 0x8e: return "DW_OP_breg30";
186     case 0x8f: return "DW_OP_breg31";
187     case 0x90: return "DW_OP_regx";
188     case 0x91: return "DW_OP_fbreg";
189     case 0x92: return "DW_OP_bregx";
190     case 0x93: return "DW_OP_piece";
191     case 0x94: return "DW_OP_deref_size";
192     case 0x95: return "DW_OP_xderef_size";
193     case 0x96: return "DW_OP_nop";
194     case 0x97: return "DW_OP_push_object_address";
195     case 0x98: return "DW_OP_call2";
196     case 0x99: return "DW_OP_call4";
197     case 0x9a: return "DW_OP_call_ref";
198 //    case DW_OP_APPLE_array_ref: return "DW_OP_APPLE_array_ref";
199 //    case DW_OP_APPLE_extern: return "DW_OP_APPLE_extern";
200     case DW_OP_APPLE_uninit: return "DW_OP_APPLE_uninit";
201 //    case DW_OP_APPLE_assign: return "DW_OP_APPLE_assign";
202 //    case DW_OP_APPLE_address_of: return "DW_OP_APPLE_address_of";
203 //    case DW_OP_APPLE_value_of: return "DW_OP_APPLE_value_of";
204 //    case DW_OP_APPLE_deref_type: return "DW_OP_APPLE_deref_type";
205 //    case DW_OP_APPLE_expr_local: return "DW_OP_APPLE_expr_local";
206 //    case DW_OP_APPLE_constf: return "DW_OP_APPLE_constf";
207 //    case DW_OP_APPLE_scalar_cast: return "DW_OP_APPLE_scalar_cast";
208 //    case DW_OP_APPLE_clang_cast: return "DW_OP_APPLE_clang_cast";
209 //    case DW_OP_APPLE_clear: return "DW_OP_APPLE_clear";
210 //    case DW_OP_APPLE_error: return "DW_OP_APPLE_error";
211     default:
212        snprintf (invalid, sizeof(invalid), "Unknown DW_OP constant: 0x%x", val);
213        return invalid;
214   }
215 }
216 
217 
218 //----------------------------------------------------------------------
219 // DWARFExpression constructor
220 //----------------------------------------------------------------------
221 DWARFExpression::DWARFExpression() :
222     m_data(),
223     m_reg_kind (eRegisterKindDWARF),
224     m_loclist_slide (LLDB_INVALID_ADDRESS)
225 {
226 }
227 
228 DWARFExpression::DWARFExpression(const DWARFExpression& rhs) :
229     m_data(rhs.m_data),
230     m_reg_kind (rhs.m_reg_kind),
231     m_loclist_slide(rhs.m_loclist_slide)
232 {
233 }
234 
235 
236 DWARFExpression::DWARFExpression(const DataExtractor& data, uint32_t data_offset, uint32_t data_length) :
237     m_data(data, data_offset, data_length),
238     m_reg_kind (eRegisterKindDWARF),
239     m_loclist_slide(LLDB_INVALID_ADDRESS)
240 {
241 }
242 
243 //----------------------------------------------------------------------
244 // Destructor
245 //----------------------------------------------------------------------
246 DWARFExpression::~DWARFExpression()
247 {
248 }
249 
250 
251 bool
252 DWARFExpression::IsValid() const
253 {
254     return m_data.GetByteSize() > 0;
255 }
256 
257 void
258 DWARFExpression::SetOpcodeData (const DataExtractor& data)
259 {
260     m_data = data;
261 }
262 
263 void
264 DWARFExpression::SetOpcodeData (const DataExtractor& data, uint32_t data_offset, uint32_t data_length)
265 {
266     m_data.SetData(data, data_offset, data_length);
267 }
268 
269 void
270 DWARFExpression::DumpLocation (Stream *s, uint32_t offset, uint32_t length, lldb::DescriptionLevel level, ABI *abi) const
271 {
272     if (!m_data.ValidOffsetForDataOfSize(offset, length))
273         return;
274     const uint32_t start_offset = offset;
275     const uint32_t end_offset = offset + length;
276     while (m_data.ValidOffset(offset) && offset < end_offset)
277     {
278         const uint32_t op_offset = offset;
279         const uint8_t op = m_data.GetU8(&offset);
280 
281         switch (level)
282         {
283         default:
284             break;
285 
286         case lldb::eDescriptionLevelBrief:
287             if (offset > start_offset)
288                 s->PutChar(' ');
289             break;
290 
291         case lldb::eDescriptionLevelFull:
292         case lldb::eDescriptionLevelVerbose:
293             if (offset > start_offset)
294                 s->EOL();
295             s->Indent();
296             if (level == lldb::eDescriptionLevelFull)
297                 break;
298             // Fall through for verbose and print offset and DW_OP prefix..
299             s->Printf("0x%8.8x: %s", op_offset, op >= DW_OP_APPLE_uninit ? "DW_OP_APPLE_" : "DW_OP_");
300             break;
301         }
302 
303         switch (op)
304         {
305         case DW_OP_addr:    *s << "DW_OP_addr(" << m_data.GetAddress(&offset) << ") "; break;         // 0x03 1 address
306         case DW_OP_deref:   *s << "DW_OP_deref"; break;                                               // 0x06
307         case DW_OP_const1u: s->Printf("DW_OP_const1u(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x08 1 1-byte constant
308         case DW_OP_const1s: s->Printf("DW_OP_const1s(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x09 1 1-byte constant
309         case DW_OP_const2u: s->Printf("DW_OP_const2u(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0a 1 2-byte constant
310         case DW_OP_const2s: s->Printf("DW_OP_const2s(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0b 1 2-byte constant
311         case DW_OP_const4u: s->Printf("DW_OP_const4u(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0c 1 4-byte constant
312         case DW_OP_const4s: s->Printf("DW_OP_const4s(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0d 1 4-byte constant
313         case DW_OP_const8u: s->Printf("DW_OP_const8u(0x%16.16llx) ", m_data.GetU64(&offset)); break;  // 0x0e 1 8-byte constant
314         case DW_OP_const8s: s->Printf("DW_OP_const8s(0x%16.16llx) ", m_data.GetU64(&offset)); break;  // 0x0f 1 8-byte constant
315         case DW_OP_constu:  s->Printf("DW_OP_constu(0x%llx) ", m_data.GetULEB128(&offset)); break;    // 0x10 1 ULEB128 constant
316         case DW_OP_consts:  s->Printf("DW_OP_consts(0x%lld) ", m_data.GetSLEB128(&offset)); break;    // 0x11 1 SLEB128 constant
317         case DW_OP_dup:     s->PutCString("DW_OP_dup"); break;                                        // 0x12
318         case DW_OP_drop:    s->PutCString("DW_OP_drop"); break;                                       // 0x13
319         case DW_OP_over:    s->PutCString("DW_OP_over"); break;                                       // 0x14
320         case DW_OP_pick:    s->Printf("DW_OP_pick(0x%2.2x) ", m_data.GetU8(&offset)); break;          // 0x15 1 1-byte stack index
321         case DW_OP_swap:    s->PutCString("DW_OP_swap"); break;                                       // 0x16
322         case DW_OP_rot:     s->PutCString("DW_OP_rot"); break;                                        // 0x17
323         case DW_OP_xderef:  s->PutCString("DW_OP_xderef"); break;                                     // 0x18
324         case DW_OP_abs:     s->PutCString("DW_OP_abs"); break;                                        // 0x19
325         case DW_OP_and:     s->PutCString("DW_OP_and"); break;                                        // 0x1a
326         case DW_OP_div:     s->PutCString("DW_OP_div"); break;                                        // 0x1b
327         case DW_OP_minus:   s->PutCString("DW_OP_minus"); break;                                      // 0x1c
328         case DW_OP_mod:     s->PutCString("DW_OP_mod"); break;                                        // 0x1d
329         case DW_OP_mul:     s->PutCString("DW_OP_mul"); break;                                        // 0x1e
330         case DW_OP_neg:     s->PutCString("DW_OP_neg"); break;                                        // 0x1f
331         case DW_OP_not:     s->PutCString("DW_OP_not"); break;                                        // 0x20
332         case DW_OP_or:      s->PutCString("DW_OP_or"); break;                                         // 0x21
333         case DW_OP_plus:    s->PutCString("DW_OP_plus"); break;                                       // 0x22
334         case DW_OP_plus_uconst:                                                                 // 0x23 1 ULEB128 addend
335             s->Printf("DW_OP_plus_uconst(0x%llx) ", m_data.GetULEB128(&offset));
336             break;
337 
338         case DW_OP_shl:     s->PutCString("DW_OP_shl"); break;                                        // 0x24
339         case DW_OP_shr:     s->PutCString("DW_OP_shr"); break;                                        // 0x25
340         case DW_OP_shra:    s->PutCString("DW_OP_shra"); break;                                       // 0x26
341         case DW_OP_xor:     s->PutCString("DW_OP_xor"); break;                                        // 0x27
342         case DW_OP_skip:    s->Printf("DW_OP_skip(0x%4.4x)", m_data.GetU16(&offset)); break;          // 0x2f 1 signed 2-byte constant
343         case DW_OP_bra:     s->Printf("DW_OP_bra(0x%4.4x)", m_data.GetU16(&offset)); break;           // 0x28 1 signed 2-byte constant
344         case DW_OP_eq:      s->PutCString("DW_OP_eq"); break;                                         // 0x29
345         case DW_OP_ge:      s->PutCString("DW_OP_ge"); break;                                         // 0x2a
346         case DW_OP_gt:      s->PutCString("DW_OP_gt"); break;                                         // 0x2b
347         case DW_OP_le:      s->PutCString("DW_OP_le"); break;                                         // 0x2c
348         case DW_OP_lt:      s->PutCString("DW_OP_lt"); break;                                         // 0x2d
349         case DW_OP_ne:      s->PutCString("DW_OP_ne"); break;                                         // 0x2e
350 
351         case DW_OP_lit0:    // 0x30
352         case DW_OP_lit1:    // 0x31
353         case DW_OP_lit2:    // 0x32
354         case DW_OP_lit3:    // 0x33
355         case DW_OP_lit4:    // 0x34
356         case DW_OP_lit5:    // 0x35
357         case DW_OP_lit6:    // 0x36
358         case DW_OP_lit7:    // 0x37
359         case DW_OP_lit8:    // 0x38
360         case DW_OP_lit9:    // 0x39
361         case DW_OP_lit10:   // 0x3A
362         case DW_OP_lit11:   // 0x3B
363         case DW_OP_lit12:   // 0x3C
364         case DW_OP_lit13:   // 0x3D
365         case DW_OP_lit14:   // 0x3E
366         case DW_OP_lit15:   // 0x3F
367         case DW_OP_lit16:   // 0x40
368         case DW_OP_lit17:   // 0x41
369         case DW_OP_lit18:   // 0x42
370         case DW_OP_lit19:   // 0x43
371         case DW_OP_lit20:   // 0x44
372         case DW_OP_lit21:   // 0x45
373         case DW_OP_lit22:   // 0x46
374         case DW_OP_lit23:   // 0x47
375         case DW_OP_lit24:   // 0x48
376         case DW_OP_lit25:   // 0x49
377         case DW_OP_lit26:   // 0x4A
378         case DW_OP_lit27:   // 0x4B
379         case DW_OP_lit28:   // 0x4C
380         case DW_OP_lit29:   // 0x4D
381         case DW_OP_lit30:   // 0x4E
382         case DW_OP_lit31:   s->Printf("DW_OP_lit%i", op - DW_OP_lit0); break; // 0x4f
383 
384         case DW_OP_reg0:    // 0x50
385         case DW_OP_reg1:    // 0x51
386         case DW_OP_reg2:    // 0x52
387         case DW_OP_reg3:    // 0x53
388         case DW_OP_reg4:    // 0x54
389         case DW_OP_reg5:    // 0x55
390         case DW_OP_reg6:    // 0x56
391         case DW_OP_reg7:    // 0x57
392         case DW_OP_reg8:    // 0x58
393         case DW_OP_reg9:    // 0x59
394         case DW_OP_reg10:   // 0x5A
395         case DW_OP_reg11:   // 0x5B
396         case DW_OP_reg12:   // 0x5C
397         case DW_OP_reg13:   // 0x5D
398         case DW_OP_reg14:   // 0x5E
399         case DW_OP_reg15:   // 0x5F
400         case DW_OP_reg16:   // 0x60
401         case DW_OP_reg17:   // 0x61
402         case DW_OP_reg18:   // 0x62
403         case DW_OP_reg19:   // 0x63
404         case DW_OP_reg20:   // 0x64
405         case DW_OP_reg21:   // 0x65
406         case DW_OP_reg22:   // 0x66
407         case DW_OP_reg23:   // 0x67
408         case DW_OP_reg24:   // 0x68
409         case DW_OP_reg25:   // 0x69
410         case DW_OP_reg26:   // 0x6A
411         case DW_OP_reg27:   // 0x6B
412         case DW_OP_reg28:   // 0x6C
413         case DW_OP_reg29:   // 0x6D
414         case DW_OP_reg30:   // 0x6E
415         case DW_OP_reg31:   // 0x6F
416             {
417                 uint32_t reg_num = op - DW_OP_reg0;
418                 if (abi)
419                 {
420                     RegisterInfo reg_info;
421                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
422                     {
423                         if (reg_info.name)
424                         {
425                             s->PutCString (reg_info.name);
426                             break;
427                         }
428                         else if (reg_info.alt_name)
429                         {
430                             s->PutCString (reg_info.alt_name);
431                             break;
432                         }
433                     }
434                 }
435                 s->Printf("DW_OP_reg%u", reg_num); break;
436             }
437             break;
438 
439         case DW_OP_breg0:
440         case DW_OP_breg1:
441         case DW_OP_breg2:
442         case DW_OP_breg3:
443         case DW_OP_breg4:
444         case DW_OP_breg5:
445         case DW_OP_breg6:
446         case DW_OP_breg7:
447         case DW_OP_breg8:
448         case DW_OP_breg9:
449         case DW_OP_breg10:
450         case DW_OP_breg11:
451         case DW_OP_breg12:
452         case DW_OP_breg13:
453         case DW_OP_breg14:
454         case DW_OP_breg15:
455         case DW_OP_breg16:
456         case DW_OP_breg17:
457         case DW_OP_breg18:
458         case DW_OP_breg19:
459         case DW_OP_breg20:
460         case DW_OP_breg21:
461         case DW_OP_breg22:
462         case DW_OP_breg23:
463         case DW_OP_breg24:
464         case DW_OP_breg25:
465         case DW_OP_breg26:
466         case DW_OP_breg27:
467         case DW_OP_breg28:
468         case DW_OP_breg29:
469         case DW_OP_breg30:
470         case DW_OP_breg31:
471             {
472                 uint32_t reg_num = op - DW_OP_breg0;
473                 int64_t reg_offset = m_data.GetSLEB128(&offset);
474                 if (abi)
475                 {
476                     RegisterInfo reg_info;
477                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
478                     {
479                         if (reg_info.name)
480                         {
481                             s->Printf("[%s%+lli]", reg_info.name, reg_offset);
482                             break;
483                         }
484                         else if (reg_info.alt_name)
485                         {
486                             s->Printf("[%s%+lli]", reg_info.alt_name, reg_offset);
487                             break;
488                         }
489                     }
490                 }
491                 s->Printf("DW_OP_breg%i(0x%llx)", reg_num, reg_offset);
492             }
493             break;
494 
495         case DW_OP_regx:                                                    // 0x90 1 ULEB128 register
496             {
497                 uint64_t reg_num = m_data.GetULEB128(&offset);
498                 if (abi)
499                 {
500                     RegisterInfo reg_info;
501                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
502                     {
503                         if (reg_info.name)
504                         {
505                             s->PutCString (reg_info.name);
506                             break;
507                         }
508                         else if (reg_info.alt_name)
509                         {
510                             s->PutCString (reg_info.alt_name);
511                             break;
512                         }
513                     }
514                 }
515                 s->Printf("DW_OP_regx(%llu)", reg_num); break;
516             }
517             break;
518         case DW_OP_fbreg:                                                   // 0x91 1 SLEB128 offset
519             s->Printf("DW_OP_fbreg(%lli)",m_data.GetSLEB128(&offset));
520             break;
521         case DW_OP_bregx:                                                   // 0x92 2 ULEB128 register followed by SLEB128 offset
522             {
523                 uint32_t reg_num = m_data.GetULEB128(&offset);
524                 int64_t reg_offset = m_data.GetSLEB128(&offset);
525                 if (abi)
526                 {
527                     RegisterInfo reg_info;
528                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
529                     {
530                         if (reg_info.name)
531                         {
532                             s->Printf("[%s%+lli]", reg_info.name, reg_offset);
533                             break;
534                         }
535                         else if (reg_info.alt_name)
536                         {
537                             s->Printf("[%s%+lli]", reg_info.alt_name, reg_offset);
538                             break;
539                         }
540                     }
541                 }
542                 s->Printf("DW_OP_bregx(reg=%u,offset=%lli)", reg_num, reg_offset);
543             }
544             break;
545         case DW_OP_piece:                                                   // 0x93 1 ULEB128 size of piece addressed
546             s->Printf("DW_OP_piece(0x%llx)", m_data.GetULEB128(&offset));
547             break;
548         case DW_OP_deref_size:                                              // 0x94 1 1-byte size of data retrieved
549             s->Printf("DW_OP_deref_size(0x%2.2x)", m_data.GetU8(&offset));
550             break;
551         case DW_OP_xderef_size:                                             // 0x95 1 1-byte size of data retrieved
552             s->Printf("DW_OP_xderef_size(0x%2.2x)", m_data.GetU8(&offset));
553             break;
554         case DW_OP_nop: s->PutCString("DW_OP_nop"); break;                                    // 0x96
555         case DW_OP_push_object_address: s->PutCString("DW_OP_push_object_address"); break;    // 0x97 DWARF3
556         case DW_OP_call2:                                                   // 0x98 DWARF3 1 2-byte offset of DIE
557             s->Printf("DW_OP_call2(0x%4.4x)", m_data.GetU16(&offset));
558             break;
559         case DW_OP_call4:                                                   // 0x99 DWARF3 1 4-byte offset of DIE
560             s->Printf("DW_OP_call4(0x%8.8x)", m_data.GetU32(&offset));
561             break;
562         case DW_OP_call_ref:                                                // 0x9a DWARF3 1 4- or 8-byte offset of DIE
563             s->Printf("DW_OP_call_ref(0x%8.8llx)", m_data.GetAddress(&offset));
564             break;
565 //      case DW_OP_form_tls_address: s << "form_tls_address"; break;        // 0x9b DWARF3
566 //      case DW_OP_call_frame_cfa: s << "call_frame_cfa"; break;            // 0x9c DWARF3
567 //      case DW_OP_bit_piece:                                               // 0x9d DWARF3 2
568 //          s->Printf("DW_OP_bit_piece(0x%x, 0x%x)", m_data.GetULEB128(&offset), m_data.GetULEB128(&offset));
569 //          break;
570 //      case DW_OP_lo_user:     s->PutCString("DW_OP_lo_user"); break;                        // 0xe0
571 //      case DW_OP_hi_user:     s->PutCString("DW_OP_hi_user"); break;                        // 0xff
572 //        case DW_OP_APPLE_extern:
573 //            s->Printf("DW_OP_APPLE_extern(%llu)", m_data.GetULEB128(&offset));
574 //            break;
575 //        case DW_OP_APPLE_array_ref:
576 //            s->PutCString("DW_OP_APPLE_array_ref");
577 //            break;
578         case DW_OP_APPLE_uninit:
579             s->PutCString("DW_OP_APPLE_uninit");  // 0xF0
580             break;
581 //        case DW_OP_APPLE_assign:        // 0xF1 - pops value off and assigns it to second item on stack (2nd item must have assignable context)
582 //            s->PutCString("DW_OP_APPLE_assign");
583 //            break;
584 //        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)
585 //            s->PutCString("DW_OP_APPLE_address_of");
586 //            break;
587 //        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)
588 //            s->PutCString("DW_OP_APPLE_value_of");
589 //            break;
590 //        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)
591 //            s->PutCString("DW_OP_APPLE_deref_type");
592 //            break;
593 //        case DW_OP_APPLE_expr_local:    // 0xF5 - ULEB128 expression local index
594 //            s->Printf("DW_OP_APPLE_expr_local(%llu)", m_data.GetULEB128(&offset));
595 //            break;
596 //        case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
597 //            {
598 //                uint8_t float_length = m_data.GetU8(&offset);
599 //                s->Printf("DW_OP_APPLE_constf(<%u> ", float_length);
600 //                m_data.Dump(s, offset, eFormatHex, float_length, 1, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
601 //                s->PutChar(')');
602 //                // Consume the float data
603 //                m_data.GetData(&offset, float_length);
604 //            }
605 //            break;
606 //        case DW_OP_APPLE_scalar_cast:
607 //            s->Printf("DW_OP_APPLE_scalar_cast(%s)", Scalar::GetValueTypeAsCString ((Scalar::Type)m_data.GetU8(&offset)));
608 //            break;
609 //        case DW_OP_APPLE_clang_cast:
610 //            {
611 //                clang::Type *clang_type = (clang::Type *)m_data.GetMaxU64(&offset, sizeof(void*));
612 //                s->Printf("DW_OP_APPLE_clang_cast(%p)", clang_type);
613 //            }
614 //            break;
615 //        case DW_OP_APPLE_clear:
616 //            s->PutCString("DW_OP_APPLE_clear");
617 //            break;
618 //        case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
619 //            s->PutCString("DW_OP_APPLE_error");
620 //            break;
621         }
622     }
623 }
624 
625 void
626 DWARFExpression::SetLocationListSlide (addr_t slide)
627 {
628     m_loclist_slide = slide;
629 }
630 
631 int
632 DWARFExpression::GetRegisterKind ()
633 {
634     return m_reg_kind;
635 }
636 
637 void
638 DWARFExpression::SetRegisterKind (RegisterKind reg_kind)
639 {
640     m_reg_kind = reg_kind;
641 }
642 
643 bool
644 DWARFExpression::IsLocationList() const
645 {
646     return m_loclist_slide != LLDB_INVALID_ADDRESS;
647 }
648 
649 void
650 DWARFExpression::GetDescription (Stream *s, lldb::DescriptionLevel level, addr_t location_list_base_addr, ABI *abi) const
651 {
652     if (IsLocationList())
653     {
654         // We have a location list
655         uint32_t offset = 0;
656         uint32_t count = 0;
657         addr_t curr_base_addr = location_list_base_addr;
658         while (m_data.ValidOffset(offset))
659         {
660             lldb::addr_t begin_addr_offset = m_data.GetAddress(&offset);
661             lldb::addr_t end_addr_offset = m_data.GetAddress(&offset);
662             if (begin_addr_offset < end_addr_offset)
663             {
664                 if (count > 0)
665                     s->PutCString(", ");
666                 VMRange addr_range(curr_base_addr + begin_addr_offset, curr_base_addr + end_addr_offset);
667                 addr_range.Dump(s, 0, 8);
668                 s->PutChar('{');
669                 uint32_t location_length = m_data.GetU16(&offset);
670                 DumpLocation (s, offset, location_length, level, abi);
671                 s->PutChar('}');
672                 offset += location_length;
673             }
674             else if (begin_addr_offset == 0 && end_addr_offset == 0)
675             {
676                 // The end of the location list is marked by both the start and end offset being zero
677                 break;
678             }
679             else
680             {
681                 if ((m_data.GetAddressByteSize() == 4 && (begin_addr_offset == UINT32_MAX)) ||
682                     (m_data.GetAddressByteSize() == 8 && (begin_addr_offset == UINT64_MAX)))
683                 {
684                     curr_base_addr = end_addr_offset + location_list_base_addr;
685                     // We have a new base address
686                     if (count > 0)
687                         s->PutCString(", ");
688                     *s << "base_addr = " << end_addr_offset;
689                 }
690             }
691 
692             count++;
693         }
694     }
695     else
696     {
697         // We have a normal location that contains DW_OP location opcodes
698         DumpLocation (s, 0, m_data.GetByteSize(), level, abi);
699     }
700 }
701 
702 static bool
703 ReadRegisterValueAsScalar
704 (
705     RegisterContext *reg_ctx,
706     uint32_t reg_kind,
707     uint32_t reg_num,
708     Error *error_ptr,
709     Value &value
710 )
711 {
712     if (reg_ctx == NULL)
713     {
714         if (error_ptr)
715             error_ptr->SetErrorStringWithFormat("No register context in frame.\n");
716     }
717     else
718     {
719         uint32_t native_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
720         if (native_reg == LLDB_INVALID_REGNUM)
721         {
722             if (error_ptr)
723                 error_ptr->SetErrorStringWithFormat("Unable to convert register kind=%u reg_num=%u to a native register number.\n", reg_kind, reg_num);
724         }
725         else
726         {
727             const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(native_reg);
728             RegisterValue reg_value;
729             if (reg_ctx->ReadRegister (reg_info, reg_value))
730             {
731                 if (reg_value.GetScalarValue(value.GetScalar()))
732                 {
733                     value.SetValueType (Value::eValueTypeScalar);
734                     value.SetContext (Value::eContextTypeRegisterInfo,
735                                       const_cast<RegisterInfo *>(reg_info));
736                     if (error_ptr)
737                         error_ptr->Clear();
738                     return true;
739                 }
740                 else
741                 {
742                     // If we get this error, then we need to implement a value
743                     // buffer in the dwarf expression evaluation function...
744                     if (error_ptr)
745                         error_ptr->SetErrorStringWithFormat ("register %s can't be converted to a scalar value",
746                                                              reg_info->name);
747                 }
748             }
749             else
750             {
751                 if (error_ptr)
752                     error_ptr->SetErrorStringWithFormat("register %s is not available", reg_info->name);
753             }
754         }
755     }
756     return false;
757 }
758 
759 //bool
760 //DWARFExpression::LocationListContainsLoadAddress (Process* process, const Address &addr) const
761 //{
762 //    return LocationListContainsLoadAddress(process, addr.GetLoadAddress(process));
763 //}
764 //
765 //bool
766 //DWARFExpression::LocationListContainsLoadAddress (Process* process, addr_t load_addr) const
767 //{
768 //    if (load_addr == LLDB_INVALID_ADDRESS)
769 //        return false;
770 //
771 //    if (IsLocationList())
772 //    {
773 //        uint32_t offset = 0;
774 //
775 //        addr_t loc_list_base_addr = m_loclist_slide.GetLoadAddress(process);
776 //
777 //        if (loc_list_base_addr == LLDB_INVALID_ADDRESS)
778 //            return false;
779 //
780 //        while (m_data.ValidOffset(offset))
781 //        {
782 //            // We need to figure out what the value is for the location.
783 //            addr_t lo_pc = m_data.GetAddress(&offset);
784 //            addr_t hi_pc = m_data.GetAddress(&offset);
785 //            if (lo_pc == 0 && hi_pc == 0)
786 //                break;
787 //            else
788 //            {
789 //                lo_pc += loc_list_base_addr;
790 //                hi_pc += loc_list_base_addr;
791 //
792 //                if (lo_pc <= load_addr && load_addr < hi_pc)
793 //                    return true;
794 //
795 //                offset += m_data.GetU16(&offset);
796 //            }
797 //        }
798 //    }
799 //    return false;
800 //}
801 
802 static uint32_t
803 GetOpcodeDataSize (const DataExtractor &data, const uint32_t data_offset, const uint8_t op)
804 {
805     uint32_t offset = data_offset;
806     switch (op)
807     {
808         case DW_OP_addr:
809         case DW_OP_call_ref:    // 0x9a 1 address sized offset of DIE (DWARF3)
810             return data.GetAddressByteSize();
811 
812         // Opcodes with no arguments
813         case DW_OP_deref:   // 0x06
814         case DW_OP_dup:     // 0x12
815         case DW_OP_drop:    // 0x13
816         case DW_OP_over:    // 0x14
817         case DW_OP_swap:    // 0x16
818         case DW_OP_rot:     // 0x17
819         case DW_OP_xderef:  // 0x18
820         case DW_OP_abs:     // 0x19
821         case DW_OP_and:     // 0x1a
822         case DW_OP_div:     // 0x1b
823         case DW_OP_minus:   // 0x1c
824         case DW_OP_mod:     // 0x1d
825         case DW_OP_mul:     // 0x1e
826         case DW_OP_neg:     // 0x1f
827         case DW_OP_not:     // 0x20
828         case DW_OP_or:      // 0x21
829         case DW_OP_plus:    // 0x22
830         case DW_OP_shl:     // 0x24
831         case DW_OP_shr:     // 0x25
832         case DW_OP_shra:    // 0x26
833         case DW_OP_xor:     // 0x27
834         case DW_OP_eq:      // 0x29
835         case DW_OP_ge:      // 0x2a
836         case DW_OP_gt:      // 0x2b
837         case DW_OP_le:      // 0x2c
838         case DW_OP_lt:      // 0x2d
839         case DW_OP_ne:      // 0x2e
840         case DW_OP_lit0:    // 0x30
841         case DW_OP_lit1:    // 0x31
842         case DW_OP_lit2:    // 0x32
843         case DW_OP_lit3:    // 0x33
844         case DW_OP_lit4:    // 0x34
845         case DW_OP_lit5:    // 0x35
846         case DW_OP_lit6:    // 0x36
847         case DW_OP_lit7:    // 0x37
848         case DW_OP_lit8:    // 0x38
849         case DW_OP_lit9:    // 0x39
850         case DW_OP_lit10:   // 0x3A
851         case DW_OP_lit11:   // 0x3B
852         case DW_OP_lit12:   // 0x3C
853         case DW_OP_lit13:   // 0x3D
854         case DW_OP_lit14:   // 0x3E
855         case DW_OP_lit15:   // 0x3F
856         case DW_OP_lit16:   // 0x40
857         case DW_OP_lit17:   // 0x41
858         case DW_OP_lit18:   // 0x42
859         case DW_OP_lit19:   // 0x43
860         case DW_OP_lit20:   // 0x44
861         case DW_OP_lit21:   // 0x45
862         case DW_OP_lit22:   // 0x46
863         case DW_OP_lit23:   // 0x47
864         case DW_OP_lit24:   // 0x48
865         case DW_OP_lit25:   // 0x49
866         case DW_OP_lit26:   // 0x4A
867         case DW_OP_lit27:   // 0x4B
868         case DW_OP_lit28:   // 0x4C
869         case DW_OP_lit29:   // 0x4D
870         case DW_OP_lit30:   // 0x4E
871         case DW_OP_lit31:   // 0x4f
872         case DW_OP_reg0:    // 0x50
873         case DW_OP_reg1:    // 0x51
874         case DW_OP_reg2:    // 0x52
875         case DW_OP_reg3:    // 0x53
876         case DW_OP_reg4:    // 0x54
877         case DW_OP_reg5:    // 0x55
878         case DW_OP_reg6:    // 0x56
879         case DW_OP_reg7:    // 0x57
880         case DW_OP_reg8:    // 0x58
881         case DW_OP_reg9:    // 0x59
882         case DW_OP_reg10:   // 0x5A
883         case DW_OP_reg11:   // 0x5B
884         case DW_OP_reg12:   // 0x5C
885         case DW_OP_reg13:   // 0x5D
886         case DW_OP_reg14:   // 0x5E
887         case DW_OP_reg15:   // 0x5F
888         case DW_OP_reg16:   // 0x60
889         case DW_OP_reg17:   // 0x61
890         case DW_OP_reg18:   // 0x62
891         case DW_OP_reg19:   // 0x63
892         case DW_OP_reg20:   // 0x64
893         case DW_OP_reg21:   // 0x65
894         case DW_OP_reg22:   // 0x66
895         case DW_OP_reg23:   // 0x67
896         case DW_OP_reg24:   // 0x68
897         case DW_OP_reg25:   // 0x69
898         case DW_OP_reg26:   // 0x6A
899         case DW_OP_reg27:   // 0x6B
900         case DW_OP_reg28:   // 0x6C
901         case DW_OP_reg29:   // 0x6D
902         case DW_OP_reg30:   // 0x6E
903         case DW_OP_reg31:   // 0x6F
904         case DW_OP_nop:     // 0x96
905         case DW_OP_push_object_address: // 0x97 DWARF3
906         case DW_OP_form_tls_address:    // 0x9b DWARF3
907         case DW_OP_call_frame_cfa:      // 0x9c DWARF3
908         case DW_OP_stack_value: // 0x9f DWARF4
909             return 0;
910 
911         // Opcodes with a single 1 byte arguments
912         case DW_OP_const1u:     // 0x08 1 1-byte constant
913         case DW_OP_const1s:     // 0x09 1 1-byte constant
914         case DW_OP_pick:        // 0x15 1 1-byte stack index
915         case DW_OP_deref_size:  // 0x94 1 1-byte size of data retrieved
916         case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
917             return 1;
918 
919         // Opcodes with a single 2 byte arguments
920         case DW_OP_const2u:     // 0x0a 1 2-byte constant
921         case DW_OP_const2s:     // 0x0b 1 2-byte constant
922         case DW_OP_skip:        // 0x2f 1 signed 2-byte constant
923         case DW_OP_bra:         // 0x28 1 signed 2-byte constant
924         case DW_OP_call2:       // 0x98 1 2-byte offset of DIE (DWARF3)
925             return 2;
926 
927         // Opcodes with a single 4 byte arguments
928         case DW_OP_const4u:     // 0x0c 1 4-byte constant
929         case DW_OP_const4s:     // 0x0d 1 4-byte constant
930         case DW_OP_call4:       // 0x99 1 4-byte offset of DIE (DWARF3)
931             return 4;
932 
933         // Opcodes with a single 8 byte arguments
934         case DW_OP_const8u:     // 0x0e 1 8-byte constant
935         case DW_OP_const8s:     // 0x0f 1 8-byte constant
936              return 8;
937 
938         // All opcodes that have a single ULEB (signed or unsigned) argument
939         case DW_OP_constu:      // 0x10 1 ULEB128 constant
940         case DW_OP_consts:      // 0x11 1 SLEB128 constant
941         case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
942         case DW_OP_breg0:       // 0x70 1 ULEB128 register
943         case DW_OP_breg1:       // 0x71 1 ULEB128 register
944         case DW_OP_breg2:       // 0x72 1 ULEB128 register
945         case DW_OP_breg3:       // 0x73 1 ULEB128 register
946         case DW_OP_breg4:       // 0x74 1 ULEB128 register
947         case DW_OP_breg5:       // 0x75 1 ULEB128 register
948         case DW_OP_breg6:       // 0x76 1 ULEB128 register
949         case DW_OP_breg7:       // 0x77 1 ULEB128 register
950         case DW_OP_breg8:       // 0x78 1 ULEB128 register
951         case DW_OP_breg9:       // 0x79 1 ULEB128 register
952         case DW_OP_breg10:      // 0x7a 1 ULEB128 register
953         case DW_OP_breg11:      // 0x7b 1 ULEB128 register
954         case DW_OP_breg12:      // 0x7c 1 ULEB128 register
955         case DW_OP_breg13:      // 0x7d 1 ULEB128 register
956         case DW_OP_breg14:      // 0x7e 1 ULEB128 register
957         case DW_OP_breg15:      // 0x7f 1 ULEB128 register
958         case DW_OP_breg16:      // 0x80 1 ULEB128 register
959         case DW_OP_breg17:      // 0x81 1 ULEB128 register
960         case DW_OP_breg18:      // 0x82 1 ULEB128 register
961         case DW_OP_breg19:      // 0x83 1 ULEB128 register
962         case DW_OP_breg20:      // 0x84 1 ULEB128 register
963         case DW_OP_breg21:      // 0x85 1 ULEB128 register
964         case DW_OP_breg22:      // 0x86 1 ULEB128 register
965         case DW_OP_breg23:      // 0x87 1 ULEB128 register
966         case DW_OP_breg24:      // 0x88 1 ULEB128 register
967         case DW_OP_breg25:      // 0x89 1 ULEB128 register
968         case DW_OP_breg26:      // 0x8a 1 ULEB128 register
969         case DW_OP_breg27:      // 0x8b 1 ULEB128 register
970         case DW_OP_breg28:      // 0x8c 1 ULEB128 register
971         case DW_OP_breg29:      // 0x8d 1 ULEB128 register
972         case DW_OP_breg30:      // 0x8e 1 ULEB128 register
973         case DW_OP_breg31:      // 0x8f 1 ULEB128 register
974         case DW_OP_regx:        // 0x90 1 ULEB128 register
975         case DW_OP_fbreg:       // 0x91 1 SLEB128 offset
976         case DW_OP_piece:       // 0x93 1 ULEB128 size of piece addressed
977             data.Skip_LEB128(&offset);
978             return offset - data_offset;
979 
980             // All opcodes that have a 2 ULEB (signed or unsigned) arguments
981         case DW_OP_bregx:       // 0x92 2 ULEB128 register followed by SLEB128 offset
982         case DW_OP_bit_piece:   // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
983             data.Skip_LEB128(&offset);
984             data.Skip_LEB128(&offset);
985             return offset - data_offset;
986 
987         case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size (DWARF4)
988             {
989                 uint64_t block_len = data.Skip_LEB128(&offset);
990                 offset += block_len;
991                 return offset - data_offset;
992             }
993 
994         default:
995             break;
996     }
997     return UINT32_MAX;
998 }
999 
1000 bool
1001 DWARFExpression::LocationContains_DW_OP_addr (lldb::addr_t file_addr, bool &error) const
1002 {
1003     error = false;
1004     if (IsLocationList())
1005         return false;
1006     uint32_t offset = 0;
1007     while (m_data.ValidOffset(offset))
1008     {
1009         const uint8_t op = m_data.GetU8(&offset);
1010 
1011         if (op == DW_OP_addr)
1012         {
1013             if (file_addr == LLDB_INVALID_ADDRESS)
1014                 return true;
1015             addr_t op_file_addr = m_data.GetAddress(&offset);
1016             if (op_file_addr == file_addr)
1017                 return true;
1018         }
1019         else
1020         {
1021             const uint32_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1022             if (op_arg_size == UINT32_MAX)
1023             {
1024                 error = true;
1025                 break;
1026             }
1027             offset += op_arg_size;
1028         }
1029     }
1030     return false;
1031 }
1032 
1033 bool
1034 DWARFExpression::Update_DW_OP_addr (lldb::addr_t file_addr)
1035 {
1036     if (IsLocationList())
1037         return false;
1038     uint32_t offset = 0;
1039     while (m_data.ValidOffset(offset))
1040     {
1041         const uint8_t op = m_data.GetU8(&offset);
1042 
1043         if (op == DW_OP_addr)
1044         {
1045             const uint8_t addr_byte_size = m_data.GetAddressByteSize();
1046             // We have to make a copy of the data as we don't know if this
1047             // data is from a read only memory mapped buffer, so we duplicate
1048             // all of the data first, then modify it, and if all goes well,
1049             // we then replace the data for this expression
1050 
1051             // So first we copy the data into a heap buffer
1052             std::auto_ptr<DataBufferHeap> head_data_ap (new DataBufferHeap (m_data.GetDataStart(),
1053                                                                             m_data.GetByteSize()));
1054 
1055             // Make en encoder so we can write the address into the buffer using
1056             // the correct byte order (endianness)
1057             DataEncoder encoder (head_data_ap->GetBytes(),
1058                                  head_data_ap->GetByteSize(),
1059                                  m_data.GetByteOrder(),
1060                                  addr_byte_size);
1061 
1062             // Replace the address in the new buffer
1063             if (encoder.PutMaxU64 (offset, addr_byte_size, file_addr) == UINT32_MAX)
1064                 return false;
1065 
1066             // All went well, so now we can reset the data using a shared
1067             // pointer to the heap data so "m_data" will now correctly
1068             // manage the heap data.
1069             m_data.SetData (DataBufferSP (head_data_ap.release()));
1070             return true;
1071         }
1072         else
1073         {
1074             const uint32_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1075             if (op_arg_size == UINT32_MAX)
1076                 break;
1077             offset += op_arg_size;
1078         }
1079     }
1080     return false;
1081 }
1082 
1083 bool
1084 DWARFExpression::LocationListContainsAddress (lldb::addr_t loclist_base_addr, lldb::addr_t addr) const
1085 {
1086     if (addr == LLDB_INVALID_ADDRESS)
1087         return false;
1088 
1089     if (IsLocationList())
1090     {
1091         uint32_t offset = 0;
1092 
1093         if (loclist_base_addr == LLDB_INVALID_ADDRESS)
1094             return false;
1095 
1096         while (m_data.ValidOffset(offset))
1097         {
1098             // We need to figure out what the value is for the location.
1099             addr_t lo_pc = m_data.GetAddress(&offset);
1100             addr_t hi_pc = m_data.GetAddress(&offset);
1101             if (lo_pc == 0 && hi_pc == 0)
1102                 break;
1103             else
1104             {
1105                 lo_pc += loclist_base_addr - m_loclist_slide;
1106                 hi_pc += loclist_base_addr - m_loclist_slide;
1107 
1108                 if (lo_pc <= addr && addr < hi_pc)
1109                     return true;
1110 
1111                 offset += m_data.GetU16(&offset);
1112             }
1113         }
1114     }
1115     return false;
1116 }
1117 
1118 bool
1119 DWARFExpression::GetLocation (addr_t base_addr, addr_t pc, uint32_t &offset, uint32_t &length)
1120 {
1121     offset = 0;
1122     if (!IsLocationList())
1123     {
1124         length = m_data.GetByteSize();
1125         return true;
1126     }
1127 
1128     if (base_addr != LLDB_INVALID_ADDRESS && pc != LLDB_INVALID_ADDRESS)
1129     {
1130         addr_t curr_base_addr = base_addr;
1131 
1132         while (m_data.ValidOffset(offset))
1133         {
1134             // We need to figure out what the value is for the location.
1135             addr_t lo_pc = m_data.GetAddress(&offset);
1136             addr_t hi_pc = m_data.GetAddress(&offset);
1137             if (lo_pc == 0 && hi_pc == 0)
1138             {
1139                 break;
1140             }
1141             else
1142             {
1143                 lo_pc += curr_base_addr - m_loclist_slide;
1144                 hi_pc += curr_base_addr - m_loclist_slide;
1145 
1146                 length = m_data.GetU16(&offset);
1147 
1148                 if (length > 0 && lo_pc <= pc && pc < hi_pc)
1149                     return true;
1150 
1151                 offset += length;
1152             }
1153         }
1154     }
1155     offset = UINT32_MAX;
1156     length = 0;
1157     return false;
1158 }
1159 
1160 bool
1161 DWARFExpression::DumpLocationForAddress (Stream *s,
1162                                          lldb::DescriptionLevel level,
1163                                          addr_t base_addr,
1164                                          addr_t address,
1165                                          ABI *abi)
1166 {
1167     uint32_t offset = 0;
1168     uint32_t length = 0;
1169 
1170     if (GetLocation (base_addr, address, offset, length))
1171     {
1172         if (length > 0)
1173         {
1174             DumpLocation(s, offset, length, level, abi);
1175             return true;
1176         }
1177     }
1178     return false;
1179 }
1180 
1181 bool
1182 DWARFExpression::Evaluate
1183 (
1184     ExecutionContextScope *exe_scope,
1185     clang::ASTContext *ast_context,
1186     ClangExpressionVariableList *expr_locals,
1187     ClangExpressionDeclMap *decl_map,
1188     lldb::addr_t loclist_base_load_addr,
1189     const Value* initial_value_ptr,
1190     Value& result,
1191     Error *error_ptr
1192 ) const
1193 {
1194     ExecutionContext exe_ctx (exe_scope);
1195     return Evaluate(&exe_ctx, ast_context, expr_locals, decl_map, NULL, loclist_base_load_addr, initial_value_ptr, result, error_ptr);
1196 }
1197 
1198 bool
1199 DWARFExpression::Evaluate
1200 (
1201     ExecutionContext *exe_ctx,
1202     clang::ASTContext *ast_context,
1203     ClangExpressionVariableList *expr_locals,
1204     ClangExpressionDeclMap *decl_map,
1205     RegisterContext *reg_ctx,
1206     lldb::addr_t loclist_base_load_addr,
1207     const Value* initial_value_ptr,
1208     Value& result,
1209     Error *error_ptr
1210 ) const
1211 {
1212     if (IsLocationList())
1213     {
1214         uint32_t offset = 0;
1215         addr_t pc;
1216         StackFrame *frame = NULL;
1217         if (reg_ctx)
1218             pc = reg_ctx->GetPC();
1219         else
1220         {
1221             frame = exe_ctx->GetFramePtr();
1222             if (!frame)
1223                 return false;
1224             RegisterContextSP reg_ctx_sp = frame->GetRegisterContext();
1225             if (!reg_ctx_sp)
1226                 return false;
1227             pc = reg_ctx_sp->GetPC();
1228         }
1229 
1230         if (loclist_base_load_addr != LLDB_INVALID_ADDRESS)
1231         {
1232             if (pc == LLDB_INVALID_ADDRESS)
1233             {
1234                 if (error_ptr)
1235                     error_ptr->SetErrorString("Invalid PC in frame.");
1236                 return false;
1237             }
1238 
1239             addr_t curr_loclist_base_load_addr = loclist_base_load_addr;
1240 
1241             while (m_data.ValidOffset(offset))
1242             {
1243                 // We need to figure out what the value is for the location.
1244                 addr_t lo_pc = m_data.GetAddress(&offset);
1245                 addr_t hi_pc = m_data.GetAddress(&offset);
1246                 if (lo_pc == 0 && hi_pc == 0)
1247                 {
1248                     break;
1249                 }
1250                 else
1251                 {
1252                     lo_pc += curr_loclist_base_load_addr - m_loclist_slide;
1253                     hi_pc += curr_loclist_base_load_addr - m_loclist_slide;
1254 
1255                     uint16_t length = m_data.GetU16(&offset);
1256 
1257                     if (length > 0 && lo_pc <= pc && pc < hi_pc)
1258                     {
1259                         return DWARFExpression::Evaluate (exe_ctx, ast_context, expr_locals, decl_map, reg_ctx, m_data, offset, length, m_reg_kind, initial_value_ptr, result, error_ptr);
1260                     }
1261                     offset += length;
1262                 }
1263             }
1264         }
1265         if (error_ptr)
1266             error_ptr->SetErrorString ("variable not available");
1267         return false;
1268     }
1269 
1270     // Not a location list, just a single expression.
1271     return DWARFExpression::Evaluate (exe_ctx, ast_context, expr_locals, decl_map, reg_ctx, m_data, 0, m_data.GetByteSize(), m_reg_kind, initial_value_ptr, result, error_ptr);
1272 }
1273 
1274 
1275 
1276 bool
1277 DWARFExpression::Evaluate
1278 (
1279     ExecutionContext *exe_ctx,
1280     clang::ASTContext *ast_context,
1281     ClangExpressionVariableList *expr_locals,
1282     ClangExpressionDeclMap *decl_map,
1283     RegisterContext *reg_ctx,
1284     const DataExtractor& opcodes,
1285     const uint32_t opcodes_offset,
1286     const uint32_t opcodes_length,
1287     const uint32_t reg_kind,
1288     const Value* initial_value_ptr,
1289     Value& result,
1290     Error *error_ptr
1291 )
1292 {
1293     std::vector<Value> stack;
1294 
1295     Process *process = NULL;
1296     StackFrame *frame = NULL;
1297 
1298     if (exe_ctx)
1299     {
1300         process = exe_ctx->GetProcessPtr();
1301         frame = exe_ctx->GetFramePtr();
1302     }
1303     if (reg_ctx == NULL && frame)
1304         reg_ctx = frame->GetRegisterContext().get();
1305 
1306     if (initial_value_ptr)
1307         stack.push_back(*initial_value_ptr);
1308 
1309     uint32_t offset = opcodes_offset;
1310     const uint32_t end_offset = opcodes_offset + opcodes_length;
1311     Value tmp;
1312     uint32_t reg_num;
1313 
1314     // Make sure all of the data is available in opcodes.
1315     if (!opcodes.ValidOffsetForDataOfSize(opcodes_offset, opcodes_length))
1316     {
1317         if (error_ptr)
1318             error_ptr->SetErrorString ("Invalid offset and/or length for opcodes buffer.");
1319         return false;
1320     }
1321     LogSP log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1322 
1323 
1324     while (opcodes.ValidOffset(offset) && offset < end_offset)
1325     {
1326         const uint32_t op_offset = offset;
1327         const uint8_t op = opcodes.GetU8(&offset);
1328 
1329         if (log && log->GetVerbose())
1330         {
1331             size_t count = stack.size();
1332             log->Printf("Stack before operation has %lu values:", count);
1333             for (size_t i=0; i<count; ++i)
1334             {
1335                 StreamString new_value;
1336                 new_value.Printf("[%zu]", i);
1337                 stack[i].Dump(&new_value);
1338                 log->Printf("  %s", new_value.GetData());
1339             }
1340             log->Printf("0x%8.8x: %s", op_offset, DW_OP_value_to_name(op));
1341         }
1342         switch (op)
1343         {
1344         //----------------------------------------------------------------------
1345         // The DW_OP_addr operation has a single operand that encodes a machine
1346         // address and whose size is the size of an address on the target machine.
1347         //----------------------------------------------------------------------
1348         case DW_OP_addr:
1349             stack.push_back(Scalar(opcodes.GetAddress(&offset)));
1350             stack.back().SetValueType (Value::eValueTypeFileAddress);
1351             break;
1352 
1353         //----------------------------------------------------------------------
1354         // The DW_OP_addr_sect_offset4 is used for any location expressions in
1355         // shared libraries that have a location like:
1356         //  DW_OP_addr(0x1000)
1357         // If this address resides in a shared library, then this virtual
1358         // address won't make sense when it is evaluated in the context of a
1359         // running process where shared libraries have been slid. To account for
1360         // this, this new address type where we can store the section pointer
1361         // and a 4 byte offset.
1362         //----------------------------------------------------------------------
1363 //      case DW_OP_addr_sect_offset4:
1364 //          {
1365 //              result_type = eResultTypeFileAddress;
1366 //              lldb::Section *sect = (lldb::Section *)opcodes.GetMaxU64(&offset, sizeof(void *));
1367 //              lldb::addr_t sect_offset = opcodes.GetU32(&offset);
1368 //
1369 //              Address so_addr (sect, sect_offset);
1370 //              lldb::addr_t load_addr = so_addr.GetLoadAddress();
1371 //              if (load_addr != LLDB_INVALID_ADDRESS)
1372 //              {
1373 //                  // We successfully resolve a file address to a load
1374 //                  // address.
1375 //                  stack.push_back(load_addr);
1376 //                  break;
1377 //              }
1378 //              else
1379 //              {
1380 //                  // We were able
1381 //                  if (error_ptr)
1382 //                      error_ptr->SetErrorStringWithFormat ("Section %s in %s is not currently loaded.\n", sect->GetName().AsCString(), sect->GetModule()->GetFileSpec().GetFilename().AsCString());
1383 //                  return false;
1384 //              }
1385 //          }
1386 //          break;
1387 
1388         //----------------------------------------------------------------------
1389         // OPCODE: DW_OP_deref
1390         // OPERANDS: none
1391         // DESCRIPTION: Pops the top stack entry and treats it as an address.
1392         // The value retrieved from that address is pushed. The size of the
1393         // data retrieved from the dereferenced address is the size of an
1394         // address on the target machine.
1395         //----------------------------------------------------------------------
1396         case DW_OP_deref:
1397             {
1398                 Value::ValueType value_type = stack.back().GetValueType();
1399                 switch (value_type)
1400                 {
1401                 case Value::eValueTypeHostAddress:
1402                     {
1403                         void *src = (void *)stack.back().GetScalar().ULongLong();
1404                         intptr_t ptr;
1405                         ::memcpy (&ptr, src, sizeof(void *));
1406                         stack.back().GetScalar() = ptr;
1407                         stack.back().ClearContext();
1408                     }
1409                     break;
1410                 case Value::eValueTypeLoadAddress:
1411                     if (exe_ctx)
1412                     {
1413                         if (process)
1414                         {
1415                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1416                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1417                             uint32_t addr_size = process->GetAddressByteSize();
1418                             Error error;
1419                             if (process->ReadMemory(pointer_addr, &addr_bytes, addr_size, error) == addr_size)
1420                             {
1421                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), addr_size);
1422                                 uint32_t addr_data_offset = 0;
1423                                 stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1424                                 stack.back().ClearContext();
1425                             }
1426                             else
1427                             {
1428                                 if (error_ptr)
1429                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%llx for DW_OP_deref: %s\n",
1430                                                                          pointer_addr,
1431                                                                          error.AsCString());
1432                                 return false;
1433                             }
1434                         }
1435                         else
1436                         {
1437                             if (error_ptr)
1438                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1439                             return false;
1440                         }
1441                     }
1442                     else
1443                     {
1444                         if (error_ptr)
1445                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1446                         return false;
1447                     }
1448                     break;
1449 
1450                 default:
1451                     break;
1452                 }
1453 
1454             }
1455             break;
1456 
1457         //----------------------------------------------------------------------
1458         // OPCODE: DW_OP_deref_size
1459         // OPERANDS: 1
1460         //  1 - uint8_t that specifies the size of the data to dereference.
1461         // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
1462         // stack entry and treats it as an address. The value retrieved from that
1463         // address is pushed. In the DW_OP_deref_size operation, however, the
1464         // size in bytes of the data retrieved from the dereferenced address is
1465         // specified by the single operand. This operand is a 1-byte unsigned
1466         // integral constant whose value may not be larger than the size of an
1467         // address on the target machine. The data retrieved is zero extended
1468         // to the size of an address on the target machine before being pushed
1469         // on the expression stack.
1470         //----------------------------------------------------------------------
1471         case DW_OP_deref_size:
1472             {
1473                 uint8_t size = opcodes.GetU8(&offset);
1474                 Value::ValueType value_type = stack.back().GetValueType();
1475                 switch (value_type)
1476                 {
1477                 case Value::eValueTypeHostAddress:
1478                     {
1479                         void *src = (void *)stack.back().GetScalar().ULongLong();
1480                         intptr_t ptr;
1481                         ::memcpy (&ptr, src, sizeof(void *));
1482                         // I can't decide whether the size operand should apply to the bytes in their
1483                         // lldb-host endianness or the target endianness.. I doubt this'll ever come up
1484                         // but I'll opt for assuming big endian regardless.
1485                         switch (size)
1486                         {
1487                             case 1: ptr = ptr & 0xff; break;
1488                             case 2: ptr = ptr & 0xffff; break;
1489                             case 3: ptr = ptr & 0xffffff; break;
1490                             case 4: ptr = ptr & 0xffffffff; break;
1491                             // the casts are added to work around the case where intptr_t is a 32 bit quantity;
1492                             // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this program.
1493                             case 5: ptr = (intptr_t) ptr & 0xffffffffffULL; break;
1494                             case 6: ptr = (intptr_t) ptr & 0xffffffffffffULL; break;
1495                             case 7: ptr = (intptr_t) ptr & 0xffffffffffffffULL; break;
1496                             default: break;
1497                         }
1498                         stack.back().GetScalar() = ptr;
1499                         stack.back().ClearContext();
1500                     }
1501                     break;
1502                 case Value::eValueTypeLoadAddress:
1503                     if (exe_ctx)
1504                     {
1505                         if (process)
1506                         {
1507                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1508                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1509                             Error error;
1510                             if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) == size)
1511                             {
1512                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), size);
1513                                 uint32_t addr_data_offset = 0;
1514                                 switch (size)
1515                                 {
1516                                     case 1: stack.back().GetScalar() = addr_data.GetU8(&addr_data_offset); break;
1517                                     case 2: stack.back().GetScalar() = addr_data.GetU16(&addr_data_offset); break;
1518                                     case 4: stack.back().GetScalar() = addr_data.GetU32(&addr_data_offset); break;
1519                                     case 8: stack.back().GetScalar() = addr_data.GetU64(&addr_data_offset); break;
1520                                     default: stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1521                                 }
1522                                 stack.back().ClearContext();
1523                             }
1524                             else
1525                             {
1526                                 if (error_ptr)
1527                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%llx for DW_OP_deref: %s\n",
1528                                                                          pointer_addr,
1529                                                                          error.AsCString());
1530                                 return false;
1531                             }
1532                         }
1533                         else
1534                         {
1535                             if (error_ptr)
1536                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1537                             return false;
1538                         }
1539                     }
1540                     else
1541                     {
1542                         if (error_ptr)
1543                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1544                         return false;
1545                     }
1546                     break;
1547 
1548                 default:
1549                     break;
1550                 }
1551 
1552             }
1553             break;
1554 
1555         //----------------------------------------------------------------------
1556         // OPCODE: DW_OP_xderef_size
1557         // OPERANDS: 1
1558         //  1 - uint8_t that specifies the size of the data to dereference.
1559         // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
1560         // the top of the stack is treated as an address. The second stack
1561         // entry is treated as an "address space identifier" for those
1562         // architectures that support multiple address spaces. The top two
1563         // stack elements are popped, a data item is retrieved through an
1564         // implementation-defined address calculation and pushed as the new
1565         // stack top. In the DW_OP_xderef_size operation, however, the size in
1566         // bytes of the data retrieved from the dereferenced address is
1567         // specified by the single operand. This operand is a 1-byte unsigned
1568         // integral constant whose value may not be larger than the size of an
1569         // address on the target machine. The data retrieved is zero extended
1570         // to the size of an address on the target machine before being pushed
1571         // on the expression stack.
1572         //----------------------------------------------------------------------
1573         case DW_OP_xderef_size:
1574             if (error_ptr)
1575                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
1576             return false;
1577         //----------------------------------------------------------------------
1578         // OPCODE: DW_OP_xderef
1579         // OPERANDS: none
1580         // DESCRIPTION: Provides an extended dereference mechanism. The entry at
1581         // the top of the stack is treated as an address. The second stack entry
1582         // is treated as an "address space identifier" for those architectures
1583         // that support multiple address spaces. The top two stack elements are
1584         // popped, a data item is retrieved through an implementation-defined
1585         // address calculation and pushed as the new stack top. The size of the
1586         // data retrieved from the dereferenced address is the size of an address
1587         // on the target machine.
1588         //----------------------------------------------------------------------
1589         case DW_OP_xderef:
1590             if (error_ptr)
1591                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
1592             return false;
1593 
1594         //----------------------------------------------------------------------
1595         // All DW_OP_constXXX opcodes have a single operand as noted below:
1596         //
1597         // Opcode           Operand 1
1598         // ---------------  ----------------------------------------------------
1599         // DW_OP_const1u    1-byte unsigned integer constant
1600         // DW_OP_const1s    1-byte signed integer constant
1601         // DW_OP_const2u    2-byte unsigned integer constant
1602         // DW_OP_const2s    2-byte signed integer constant
1603         // DW_OP_const4u    4-byte unsigned integer constant
1604         // DW_OP_const4s    4-byte signed integer constant
1605         // DW_OP_const8u    8-byte unsigned integer constant
1606         // DW_OP_const8s    8-byte signed integer constant
1607         // DW_OP_constu     unsigned LEB128 integer constant
1608         // DW_OP_consts     signed LEB128 integer constant
1609         //----------------------------------------------------------------------
1610         case DW_OP_const1u             :    stack.push_back(Scalar(( uint8_t)opcodes.GetU8 (&offset))); break;
1611         case DW_OP_const1s             :    stack.push_back(Scalar((  int8_t)opcodes.GetU8 (&offset))); break;
1612         case DW_OP_const2u             :    stack.push_back(Scalar((uint16_t)opcodes.GetU16 (&offset))); break;
1613         case DW_OP_const2s             :    stack.push_back(Scalar(( int16_t)opcodes.GetU16 (&offset))); break;
1614         case DW_OP_const4u             :    stack.push_back(Scalar((uint32_t)opcodes.GetU32 (&offset))); break;
1615         case DW_OP_const4s             :    stack.push_back(Scalar(( int32_t)opcodes.GetU32 (&offset))); break;
1616         case DW_OP_const8u             :    stack.push_back(Scalar((uint64_t)opcodes.GetU64 (&offset))); break;
1617         case DW_OP_const8s             :    stack.push_back(Scalar(( int64_t)opcodes.GetU64 (&offset))); break;
1618         case DW_OP_constu              :    stack.push_back(Scalar(opcodes.GetULEB128 (&offset))); break;
1619         case DW_OP_consts              :    stack.push_back(Scalar(opcodes.GetSLEB128 (&offset))); break;
1620 
1621         //----------------------------------------------------------------------
1622         // OPCODE: DW_OP_dup
1623         // OPERANDS: none
1624         // DESCRIPTION: duplicates the value at the top of the stack
1625         //----------------------------------------------------------------------
1626         case DW_OP_dup:
1627             if (stack.empty())
1628             {
1629                 if (error_ptr)
1630                     error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
1631                 return false;
1632             }
1633             else
1634                 stack.push_back(stack.back());
1635             break;
1636 
1637         //----------------------------------------------------------------------
1638         // OPCODE: DW_OP_drop
1639         // OPERANDS: none
1640         // DESCRIPTION: pops the value at the top of the stack
1641         //----------------------------------------------------------------------
1642         case DW_OP_drop:
1643             if (stack.empty())
1644             {
1645                 if (error_ptr)
1646                     error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
1647                 return false;
1648             }
1649             else
1650                 stack.pop_back();
1651             break;
1652 
1653         //----------------------------------------------------------------------
1654         // OPCODE: DW_OP_over
1655         // OPERANDS: none
1656         // DESCRIPTION: Duplicates the entry currently second in the stack at
1657         // the top of the stack.
1658         //----------------------------------------------------------------------
1659         case DW_OP_over:
1660             if (stack.size() < 2)
1661             {
1662                 if (error_ptr)
1663                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_over.");
1664                 return false;
1665             }
1666             else
1667                 stack.push_back(stack[stack.size() - 2]);
1668             break;
1669 
1670 
1671         //----------------------------------------------------------------------
1672         // OPCODE: DW_OP_pick
1673         // OPERANDS: uint8_t index into the current stack
1674         // DESCRIPTION: The stack entry with the specified index (0 through 255,
1675         // inclusive) is pushed on the stack
1676         //----------------------------------------------------------------------
1677         case DW_OP_pick:
1678             {
1679                 uint8_t pick_idx = opcodes.GetU8(&offset);
1680                 if (pick_idx < stack.size())
1681                     stack.push_back(stack[pick_idx]);
1682                 else
1683                 {
1684                     if (error_ptr)
1685                         error_ptr->SetErrorStringWithFormat("Index %u out of range for DW_OP_pick.\n", pick_idx);
1686                     return false;
1687                 }
1688             }
1689             break;
1690 
1691         //----------------------------------------------------------------------
1692         // OPCODE: DW_OP_swap
1693         // OPERANDS: none
1694         // DESCRIPTION: swaps the top two stack entries. The entry at the top
1695         // of the stack becomes the second stack entry, and the second entry
1696         // becomes the top of the stack
1697         //----------------------------------------------------------------------
1698         case DW_OP_swap:
1699             if (stack.size() < 2)
1700             {
1701                 if (error_ptr)
1702                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_swap.");
1703                 return false;
1704             }
1705             else
1706             {
1707                 tmp = stack.back();
1708                 stack.back() = stack[stack.size() - 2];
1709                 stack[stack.size() - 2] = tmp;
1710             }
1711             break;
1712 
1713         //----------------------------------------------------------------------
1714         // OPCODE: DW_OP_rot
1715         // OPERANDS: none
1716         // DESCRIPTION: Rotates the first three stack entries. The entry at
1717         // the top of the stack becomes the third stack entry, the second
1718         // entry becomes the top of the stack, and the third entry becomes
1719         // the second entry.
1720         //----------------------------------------------------------------------
1721         case DW_OP_rot:
1722             if (stack.size() < 3)
1723             {
1724                 if (error_ptr)
1725                     error_ptr->SetErrorString("Expression stack needs at least 3 items for DW_OP_rot.");
1726                 return false;
1727             }
1728             else
1729             {
1730                 size_t last_idx = stack.size() - 1;
1731                 Value old_top = stack[last_idx];
1732                 stack[last_idx] = stack[last_idx - 1];
1733                 stack[last_idx - 1] = stack[last_idx - 2];
1734                 stack[last_idx - 2] = old_top;
1735             }
1736             break;
1737 
1738         //----------------------------------------------------------------------
1739         // OPCODE: DW_OP_abs
1740         // OPERANDS: none
1741         // DESCRIPTION: pops the top stack entry, interprets it as a signed
1742         // value and pushes its absolute value. If the absolute value can not be
1743         // represented, the result is undefined.
1744         //----------------------------------------------------------------------
1745         case DW_OP_abs:
1746             if (stack.empty())
1747             {
1748                 if (error_ptr)
1749                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_abs.");
1750                 return false;
1751             }
1752             else if (stack.back().ResolveValue(exe_ctx, ast_context).AbsoluteValue() == false)
1753             {
1754                 if (error_ptr)
1755                     error_ptr->SetErrorString("Failed to take the absolute value of the first stack item.");
1756                 return false;
1757             }
1758             break;
1759 
1760         //----------------------------------------------------------------------
1761         // OPCODE: DW_OP_and
1762         // OPERANDS: none
1763         // DESCRIPTION: pops the top two stack values, performs a bitwise and
1764         // operation on the two, and pushes the result.
1765         //----------------------------------------------------------------------
1766         case DW_OP_and:
1767             if (stack.size() < 2)
1768             {
1769                 if (error_ptr)
1770                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_and.");
1771                 return false;
1772             }
1773             else
1774             {
1775                 tmp = stack.back();
1776                 stack.pop_back();
1777                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) & tmp.ResolveValue(exe_ctx, ast_context);
1778             }
1779             break;
1780 
1781         //----------------------------------------------------------------------
1782         // OPCODE: DW_OP_div
1783         // OPERANDS: none
1784         // DESCRIPTION: pops the top two stack values, divides the former second
1785         // entry by the former top of the stack using signed division, and
1786         // pushes the result.
1787         //----------------------------------------------------------------------
1788         case DW_OP_div:
1789             if (stack.size() < 2)
1790             {
1791                 if (error_ptr)
1792                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_div.");
1793                 return false;
1794             }
1795             else
1796             {
1797                 tmp = stack.back();
1798                 if (tmp.ResolveValue(exe_ctx, ast_context).IsZero())
1799                 {
1800                     if (error_ptr)
1801                         error_ptr->SetErrorString("Divide by zero.");
1802                     return false;
1803                 }
1804                 else
1805                 {
1806                     stack.pop_back();
1807                     stack.back() = stack.back().ResolveValue(exe_ctx, ast_context) / tmp.ResolveValue(exe_ctx, ast_context);
1808                     if (!stack.back().ResolveValue(exe_ctx, ast_context).IsValid())
1809                     {
1810                         if (error_ptr)
1811                             error_ptr->SetErrorString("Divide failed.");
1812                         return false;
1813                     }
1814                 }
1815             }
1816             break;
1817 
1818         //----------------------------------------------------------------------
1819         // OPCODE: DW_OP_minus
1820         // OPERANDS: none
1821         // DESCRIPTION: pops the top two stack values, subtracts the former top
1822         // of the stack from the former second entry, and pushes the result.
1823         //----------------------------------------------------------------------
1824         case DW_OP_minus:
1825             if (stack.size() < 2)
1826             {
1827                 if (error_ptr)
1828                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_minus.");
1829                 return false;
1830             }
1831             else
1832             {
1833                 tmp = stack.back();
1834                 stack.pop_back();
1835                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) - tmp.ResolveValue(exe_ctx, ast_context);
1836             }
1837             break;
1838 
1839         //----------------------------------------------------------------------
1840         // OPCODE: DW_OP_mod
1841         // OPERANDS: none
1842         // DESCRIPTION: pops the top two stack values and pushes the result of
1843         // the calculation: former second stack entry modulo the former top of
1844         // the stack.
1845         //----------------------------------------------------------------------
1846         case DW_OP_mod:
1847             if (stack.size() < 2)
1848             {
1849                 if (error_ptr)
1850                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mod.");
1851                 return false;
1852             }
1853             else
1854             {
1855                 tmp = stack.back();
1856                 stack.pop_back();
1857                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) % tmp.ResolveValue(exe_ctx, ast_context);
1858             }
1859             break;
1860 
1861 
1862         //----------------------------------------------------------------------
1863         // OPCODE: DW_OP_mul
1864         // OPERANDS: none
1865         // DESCRIPTION: pops the top two stack entries, multiplies them
1866         // together, and pushes the result.
1867         //----------------------------------------------------------------------
1868         case DW_OP_mul:
1869             if (stack.size() < 2)
1870             {
1871                 if (error_ptr)
1872                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mul.");
1873                 return false;
1874             }
1875             else
1876             {
1877                 tmp = stack.back();
1878                 stack.pop_back();
1879                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) * tmp.ResolveValue(exe_ctx, ast_context);
1880             }
1881             break;
1882 
1883         //----------------------------------------------------------------------
1884         // OPCODE: DW_OP_neg
1885         // OPERANDS: none
1886         // DESCRIPTION: pops the top stack entry, and pushes its negation.
1887         //----------------------------------------------------------------------
1888         case DW_OP_neg:
1889             if (stack.empty())
1890             {
1891                 if (error_ptr)
1892                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_neg.");
1893                 return false;
1894             }
1895             else
1896             {
1897                 if (stack.back().ResolveValue(exe_ctx, ast_context).UnaryNegate() == false)
1898                 {
1899                     if (error_ptr)
1900                         error_ptr->SetErrorString("Unary negate failed.");
1901                     return false;
1902                 }
1903             }
1904             break;
1905 
1906         //----------------------------------------------------------------------
1907         // OPCODE: DW_OP_not
1908         // OPERANDS: none
1909         // DESCRIPTION: pops the top stack entry, and pushes its bitwise
1910         // complement
1911         //----------------------------------------------------------------------
1912         case DW_OP_not:
1913             if (stack.empty())
1914             {
1915                 if (error_ptr)
1916                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_not.");
1917                 return false;
1918             }
1919             else
1920             {
1921                 if (stack.back().ResolveValue(exe_ctx, ast_context).OnesComplement() == false)
1922                 {
1923                     if (error_ptr)
1924                         error_ptr->SetErrorString("Logical NOT failed.");
1925                     return false;
1926                 }
1927             }
1928             break;
1929 
1930         //----------------------------------------------------------------------
1931         // OPCODE: DW_OP_or
1932         // OPERANDS: none
1933         // DESCRIPTION: pops the top two stack entries, performs a bitwise or
1934         // operation on the two, and pushes the result.
1935         //----------------------------------------------------------------------
1936         case DW_OP_or:
1937             if (stack.size() < 2)
1938             {
1939                 if (error_ptr)
1940                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_or.");
1941                 return false;
1942             }
1943             else
1944             {
1945                 tmp = stack.back();
1946                 stack.pop_back();
1947                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) | tmp.ResolveValue(exe_ctx, ast_context);
1948             }
1949             break;
1950 
1951         //----------------------------------------------------------------------
1952         // OPCODE: DW_OP_plus
1953         // OPERANDS: none
1954         // DESCRIPTION: pops the top two stack entries, adds them together, and
1955         // pushes the result.
1956         //----------------------------------------------------------------------
1957         case DW_OP_plus:
1958             if (stack.size() < 2)
1959             {
1960                 if (error_ptr)
1961                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_plus.");
1962                 return false;
1963             }
1964             else
1965             {
1966                 tmp = stack.back();
1967                 stack.pop_back();
1968                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) + tmp.ResolveValue(exe_ctx, ast_context);
1969             }
1970             break;
1971 
1972         //----------------------------------------------------------------------
1973         // OPCODE: DW_OP_plus_uconst
1974         // OPERANDS: none
1975         // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
1976         // constant operand and pushes the result.
1977         //----------------------------------------------------------------------
1978         case DW_OP_plus_uconst:
1979             if (stack.empty())
1980             {
1981                 if (error_ptr)
1982                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_plus_uconst.");
1983                 return false;
1984             }
1985             else
1986             {
1987                 uint32_t uconst_value = opcodes.GetULEB128(&offset);
1988                 // Implicit conversion from a UINT to a Scalar...
1989                 stack.back().ResolveValue(exe_ctx, ast_context) += uconst_value;
1990                 if (!stack.back().ResolveValue(exe_ctx, ast_context).IsValid())
1991                 {
1992                     if (error_ptr)
1993                         error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
1994                     return false;
1995                 }
1996             }
1997             break;
1998 
1999         //----------------------------------------------------------------------
2000         // OPCODE: DW_OP_shl
2001         // OPERANDS: none
2002         // DESCRIPTION:  pops the top two stack entries, shifts the former
2003         // second entry left by the number of bits specified by the former top
2004         // of the stack, and pushes the result.
2005         //----------------------------------------------------------------------
2006         case DW_OP_shl:
2007             if (stack.size() < 2)
2008             {
2009                 if (error_ptr)
2010                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shl.");
2011                 return false;
2012             }
2013             else
2014             {
2015                 tmp = stack.back();
2016                 stack.pop_back();
2017                 stack.back().ResolveValue(exe_ctx, ast_context) <<= tmp.ResolveValue(exe_ctx, ast_context);
2018             }
2019             break;
2020 
2021         //----------------------------------------------------------------------
2022         // OPCODE: DW_OP_shr
2023         // OPERANDS: none
2024         // DESCRIPTION: pops the top two stack entries, shifts the former second
2025         // entry right logically (filling with zero bits) by the number of bits
2026         // specified by the former top of the stack, and pushes the result.
2027         //----------------------------------------------------------------------
2028         case DW_OP_shr:
2029             if (stack.size() < 2)
2030             {
2031                 if (error_ptr)
2032                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shr.");
2033                 return false;
2034             }
2035             else
2036             {
2037                 tmp = stack.back();
2038                 stack.pop_back();
2039                 if (stack.back().ResolveValue(exe_ctx, ast_context).ShiftRightLogical(tmp.ResolveValue(exe_ctx, ast_context)) == false)
2040                 {
2041                     if (error_ptr)
2042                         error_ptr->SetErrorString("DW_OP_shr failed.");
2043                     return false;
2044                 }
2045             }
2046             break;
2047 
2048         //----------------------------------------------------------------------
2049         // OPCODE: DW_OP_shra
2050         // OPERANDS: none
2051         // DESCRIPTION: pops the top two stack entries, shifts the former second
2052         // entry right arithmetically (divide the magnitude by 2, keep the same
2053         // sign for the result) by the number of bits specified by the former
2054         // top of the stack, and pushes the result.
2055         //----------------------------------------------------------------------
2056         case DW_OP_shra:
2057             if (stack.size() < 2)
2058             {
2059                 if (error_ptr)
2060                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shra.");
2061                 return false;
2062             }
2063             else
2064             {
2065                 tmp = stack.back();
2066                 stack.pop_back();
2067                 stack.back().ResolveValue(exe_ctx, ast_context) >>= tmp.ResolveValue(exe_ctx, ast_context);
2068             }
2069             break;
2070 
2071         //----------------------------------------------------------------------
2072         // OPCODE: DW_OP_xor
2073         // OPERANDS: none
2074         // DESCRIPTION: pops the top two stack entries, performs the bitwise
2075         // exclusive-or operation on the two, and pushes the result.
2076         //----------------------------------------------------------------------
2077         case DW_OP_xor:
2078             if (stack.size() < 2)
2079             {
2080                 if (error_ptr)
2081                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_xor.");
2082                 return false;
2083             }
2084             else
2085             {
2086                 tmp = stack.back();
2087                 stack.pop_back();
2088                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) ^ tmp.ResolveValue(exe_ctx, ast_context);
2089             }
2090             break;
2091 
2092 
2093         //----------------------------------------------------------------------
2094         // OPCODE: DW_OP_skip
2095         // OPERANDS: int16_t
2096         // DESCRIPTION:  An unconditional branch. Its single operand is a 2-byte
2097         // signed integer constant. The 2-byte constant is the number of bytes
2098         // of the DWARF expression to skip forward or backward from the current
2099         // operation, beginning after the 2-byte constant.
2100         //----------------------------------------------------------------------
2101         case DW_OP_skip:
2102             {
2103                 int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
2104                 uint32_t new_offset = offset + skip_offset;
2105                 if (new_offset >= opcodes_offset && new_offset < end_offset)
2106                     offset = new_offset;
2107                 else
2108                 {
2109                     if (error_ptr)
2110                         error_ptr->SetErrorString("Invalid opcode offset in DW_OP_skip.");
2111                     return false;
2112                 }
2113             }
2114             break;
2115 
2116         //----------------------------------------------------------------------
2117         // OPCODE: DW_OP_bra
2118         // OPERANDS: int16_t
2119         // DESCRIPTION: A conditional branch. Its single operand is a 2-byte
2120         // signed integer constant. This operation pops the top of stack. If
2121         // the value popped is not the constant 0, the 2-byte constant operand
2122         // is the number of bytes of the DWARF expression to skip forward or
2123         // backward from the current operation, beginning after the 2-byte
2124         // constant.
2125         //----------------------------------------------------------------------
2126         case DW_OP_bra:
2127             {
2128                 tmp = stack.back();
2129                 stack.pop_back();
2130                 int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
2131                 Scalar zero(0);
2132                 if (tmp.ResolveValue(exe_ctx, ast_context) != zero)
2133                 {
2134                     uint32_t new_offset = offset + bra_offset;
2135                     if (new_offset >= opcodes_offset && new_offset < end_offset)
2136                         offset = new_offset;
2137                     else
2138                     {
2139                         if (error_ptr)
2140                             error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
2141                         return false;
2142                     }
2143                 }
2144             }
2145             break;
2146 
2147         //----------------------------------------------------------------------
2148         // OPCODE: DW_OP_eq
2149         // OPERANDS: none
2150         // DESCRIPTION: pops the top two stack values, compares using the
2151         // equals (==) operator.
2152         // STACK RESULT: push the constant value 1 onto the stack if the result
2153         // of the operation is true or the constant value 0 if the result of the
2154         // operation is false.
2155         //----------------------------------------------------------------------
2156         case DW_OP_eq:
2157             if (stack.size() < 2)
2158             {
2159                 if (error_ptr)
2160                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_eq.");
2161                 return false;
2162             }
2163             else
2164             {
2165                 tmp = stack.back();
2166                 stack.pop_back();
2167                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) == tmp.ResolveValue(exe_ctx, ast_context);
2168             }
2169             break;
2170 
2171         //----------------------------------------------------------------------
2172         // OPCODE: DW_OP_ge
2173         // OPERANDS: none
2174         // DESCRIPTION: pops the top two stack values, compares using the
2175         // greater than or equal to (>=) operator.
2176         // STACK RESULT: push the constant value 1 onto the stack if the result
2177         // of the operation is true or the constant value 0 if the result of the
2178         // operation is false.
2179         //----------------------------------------------------------------------
2180         case DW_OP_ge:
2181             if (stack.size() < 2)
2182             {
2183                 if (error_ptr)
2184                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ge.");
2185                 return false;
2186             }
2187             else
2188             {
2189                 tmp = stack.back();
2190                 stack.pop_back();
2191                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) >= tmp.ResolveValue(exe_ctx, ast_context);
2192             }
2193             break;
2194 
2195         //----------------------------------------------------------------------
2196         // OPCODE: DW_OP_gt
2197         // OPERANDS: none
2198         // DESCRIPTION: pops the top two stack values, compares using the
2199         // greater than (>) operator.
2200         // STACK RESULT: push the constant value 1 onto the stack if the result
2201         // of the operation is true or the constant value 0 if the result of the
2202         // operation is false.
2203         //----------------------------------------------------------------------
2204         case DW_OP_gt:
2205             if (stack.size() < 2)
2206             {
2207                 if (error_ptr)
2208                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_gt.");
2209                 return false;
2210             }
2211             else
2212             {
2213                 tmp = stack.back();
2214                 stack.pop_back();
2215                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) > tmp.ResolveValue(exe_ctx, ast_context);
2216             }
2217             break;
2218 
2219         //----------------------------------------------------------------------
2220         // OPCODE: DW_OP_le
2221         // OPERANDS: none
2222         // DESCRIPTION: pops the top two stack values, compares using the
2223         // less than or equal to (<=) operator.
2224         // STACK RESULT: push the constant value 1 onto the stack if the result
2225         // of the operation is true or the constant value 0 if the result of the
2226         // operation is false.
2227         //----------------------------------------------------------------------
2228         case DW_OP_le:
2229             if (stack.size() < 2)
2230             {
2231                 if (error_ptr)
2232                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_le.");
2233                 return false;
2234             }
2235             else
2236             {
2237                 tmp = stack.back();
2238                 stack.pop_back();
2239                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) <= tmp.ResolveValue(exe_ctx, ast_context);
2240             }
2241             break;
2242 
2243         //----------------------------------------------------------------------
2244         // OPCODE: DW_OP_lt
2245         // OPERANDS: none
2246         // DESCRIPTION: pops the top two stack values, compares using the
2247         // less than (<) operator.
2248         // STACK RESULT: push the constant value 1 onto the stack if the result
2249         // of the operation is true or the constant value 0 if the result of the
2250         // operation is false.
2251         //----------------------------------------------------------------------
2252         case DW_OP_lt:
2253             if (stack.size() < 2)
2254             {
2255                 if (error_ptr)
2256                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_lt.");
2257                 return false;
2258             }
2259             else
2260             {
2261                 tmp = stack.back();
2262                 stack.pop_back();
2263                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) < tmp.ResolveValue(exe_ctx, ast_context);
2264             }
2265             break;
2266 
2267         //----------------------------------------------------------------------
2268         // OPCODE: DW_OP_ne
2269         // OPERANDS: none
2270         // DESCRIPTION: pops the top two stack values, compares using the
2271         // not equal (!=) operator.
2272         // STACK RESULT: push the constant value 1 onto the stack if the result
2273         // of the operation is true or the constant value 0 if the result of the
2274         // operation is false.
2275         //----------------------------------------------------------------------
2276         case DW_OP_ne:
2277             if (stack.size() < 2)
2278             {
2279                 if (error_ptr)
2280                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ne.");
2281                 return false;
2282             }
2283             else
2284             {
2285                 tmp = stack.back();
2286                 stack.pop_back();
2287                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) != tmp.ResolveValue(exe_ctx, ast_context);
2288             }
2289             break;
2290 
2291         //----------------------------------------------------------------------
2292         // OPCODE: DW_OP_litn
2293         // OPERANDS: none
2294         // DESCRIPTION: encode the unsigned literal values from 0 through 31.
2295         // STACK RESULT: push the unsigned literal constant value onto the top
2296         // of the stack.
2297         //----------------------------------------------------------------------
2298         case DW_OP_lit0:
2299         case DW_OP_lit1:
2300         case DW_OP_lit2:
2301         case DW_OP_lit3:
2302         case DW_OP_lit4:
2303         case DW_OP_lit5:
2304         case DW_OP_lit6:
2305         case DW_OP_lit7:
2306         case DW_OP_lit8:
2307         case DW_OP_lit9:
2308         case DW_OP_lit10:
2309         case DW_OP_lit11:
2310         case DW_OP_lit12:
2311         case DW_OP_lit13:
2312         case DW_OP_lit14:
2313         case DW_OP_lit15:
2314         case DW_OP_lit16:
2315         case DW_OP_lit17:
2316         case DW_OP_lit18:
2317         case DW_OP_lit19:
2318         case DW_OP_lit20:
2319         case DW_OP_lit21:
2320         case DW_OP_lit22:
2321         case DW_OP_lit23:
2322         case DW_OP_lit24:
2323         case DW_OP_lit25:
2324         case DW_OP_lit26:
2325         case DW_OP_lit27:
2326         case DW_OP_lit28:
2327         case DW_OP_lit29:
2328         case DW_OP_lit30:
2329         case DW_OP_lit31:
2330             stack.push_back(Scalar(op - DW_OP_lit0));
2331             break;
2332 
2333         //----------------------------------------------------------------------
2334         // OPCODE: DW_OP_regN
2335         // OPERANDS: none
2336         // DESCRIPTION: Push the value in register n on the top of the stack.
2337         //----------------------------------------------------------------------
2338         case DW_OP_reg0:
2339         case DW_OP_reg1:
2340         case DW_OP_reg2:
2341         case DW_OP_reg3:
2342         case DW_OP_reg4:
2343         case DW_OP_reg5:
2344         case DW_OP_reg6:
2345         case DW_OP_reg7:
2346         case DW_OP_reg8:
2347         case DW_OP_reg9:
2348         case DW_OP_reg10:
2349         case DW_OP_reg11:
2350         case DW_OP_reg12:
2351         case DW_OP_reg13:
2352         case DW_OP_reg14:
2353         case DW_OP_reg15:
2354         case DW_OP_reg16:
2355         case DW_OP_reg17:
2356         case DW_OP_reg18:
2357         case DW_OP_reg19:
2358         case DW_OP_reg20:
2359         case DW_OP_reg21:
2360         case DW_OP_reg22:
2361         case DW_OP_reg23:
2362         case DW_OP_reg24:
2363         case DW_OP_reg25:
2364         case DW_OP_reg26:
2365         case DW_OP_reg27:
2366         case DW_OP_reg28:
2367         case DW_OP_reg29:
2368         case DW_OP_reg30:
2369         case DW_OP_reg31:
2370             {
2371                 reg_num = op - DW_OP_reg0;
2372 
2373                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2374                     stack.push_back(tmp);
2375                 else
2376                     return false;
2377             }
2378             break;
2379         //----------------------------------------------------------------------
2380         // OPCODE: DW_OP_regx
2381         // OPERANDS:
2382         //      ULEB128 literal operand that encodes the register.
2383         // DESCRIPTION: Push the value in register on the top of the stack.
2384         //----------------------------------------------------------------------
2385         case DW_OP_regx:
2386             {
2387                 reg_num = opcodes.GetULEB128(&offset);
2388                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2389                     stack.push_back(tmp);
2390                 else
2391                     return false;
2392             }
2393             break;
2394 
2395         //----------------------------------------------------------------------
2396         // OPCODE: DW_OP_bregN
2397         // OPERANDS:
2398         //      SLEB128 offset from register N
2399         // DESCRIPTION: Value is in memory at the address specified by register
2400         // N plus an offset.
2401         //----------------------------------------------------------------------
2402         case DW_OP_breg0:
2403         case DW_OP_breg1:
2404         case DW_OP_breg2:
2405         case DW_OP_breg3:
2406         case DW_OP_breg4:
2407         case DW_OP_breg5:
2408         case DW_OP_breg6:
2409         case DW_OP_breg7:
2410         case DW_OP_breg8:
2411         case DW_OP_breg9:
2412         case DW_OP_breg10:
2413         case DW_OP_breg11:
2414         case DW_OP_breg12:
2415         case DW_OP_breg13:
2416         case DW_OP_breg14:
2417         case DW_OP_breg15:
2418         case DW_OP_breg16:
2419         case DW_OP_breg17:
2420         case DW_OP_breg18:
2421         case DW_OP_breg19:
2422         case DW_OP_breg20:
2423         case DW_OP_breg21:
2424         case DW_OP_breg22:
2425         case DW_OP_breg23:
2426         case DW_OP_breg24:
2427         case DW_OP_breg25:
2428         case DW_OP_breg26:
2429         case DW_OP_breg27:
2430         case DW_OP_breg28:
2431         case DW_OP_breg29:
2432         case DW_OP_breg30:
2433         case DW_OP_breg31:
2434             {
2435                 reg_num = op - DW_OP_breg0;
2436 
2437                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2438                 {
2439                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2440                     tmp.ResolveValue(exe_ctx, ast_context) += (uint64_t)breg_offset;
2441                     tmp.ClearContext();
2442                     stack.push_back(tmp);
2443                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2444                 }
2445                 else
2446                     return false;
2447             }
2448             break;
2449         //----------------------------------------------------------------------
2450         // OPCODE: DW_OP_bregx
2451         // OPERANDS: 2
2452         //      ULEB128 literal operand that encodes the register.
2453         //      SLEB128 offset from register N
2454         // DESCRIPTION: Value is in memory at the address specified by register
2455         // N plus an offset.
2456         //----------------------------------------------------------------------
2457         case DW_OP_bregx:
2458             {
2459                 reg_num = opcodes.GetULEB128(&offset);
2460 
2461                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2462                 {
2463                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2464                     tmp.ResolveValue(exe_ctx, ast_context) += (uint64_t)breg_offset;
2465                     tmp.ClearContext();
2466                     stack.push_back(tmp);
2467                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2468                 }
2469                 else
2470                     return false;
2471             }
2472             break;
2473 
2474         case DW_OP_fbreg:
2475             if (exe_ctx)
2476             {
2477                 if (frame)
2478                 {
2479                     Scalar value;
2480                     if (frame->GetFrameBaseValue(value, error_ptr))
2481                     {
2482                         int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
2483                         value += fbreg_offset;
2484                         stack.push_back(value);
2485                         stack.back().SetValueType (Value::eValueTypeLoadAddress);
2486                     }
2487                     else
2488                         return false;
2489                 }
2490                 else
2491                 {
2492                     if (error_ptr)
2493                         error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_fbreg opcode.");
2494                     return false;
2495                 }
2496             }
2497             else
2498             {
2499                 if (error_ptr)
2500                     error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_fbreg.\n");
2501                 return false;
2502             }
2503 
2504             break;
2505 
2506         //----------------------------------------------------------------------
2507         // OPCODE: DW_OP_nop
2508         // OPERANDS: none
2509         // DESCRIPTION: A place holder. It has no effect on the location stack
2510         // or any of its values.
2511         //----------------------------------------------------------------------
2512         case DW_OP_nop:
2513             break;
2514 
2515         //----------------------------------------------------------------------
2516         // OPCODE: DW_OP_piece
2517         // OPERANDS: 1
2518         //      ULEB128: byte size of the piece
2519         // DESCRIPTION: The operand describes the size in bytes of the piece of
2520         // the object referenced by the DWARF expression whose result is at the
2521         // top of the stack. If the piece is located in a register, but does not
2522         // occupy the entire register, the placement of the piece within that
2523         // register is defined by the ABI.
2524         //
2525         // Many compilers store a single variable in sets of registers, or store
2526         // a variable partially in memory and partially in registers.
2527         // DW_OP_piece provides a way of describing how large a part of a
2528         // variable a particular DWARF expression refers to.
2529         //----------------------------------------------------------------------
2530         case DW_OP_piece:
2531             if (error_ptr)
2532                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_piece.");
2533             return false;
2534 
2535         //----------------------------------------------------------------------
2536         // OPCODE: DW_OP_push_object_address
2537         // OPERANDS: none
2538         // DESCRIPTION: Pushes the address of the object currently being
2539         // evaluated as part of evaluation of a user presented expression.
2540         // This object may correspond to an independent variable described by
2541         // its own DIE or it may be a component of an array, structure, or class
2542         // whose address has been dynamically determined by an earlier step
2543         // during user expression evaluation.
2544         //----------------------------------------------------------------------
2545         case DW_OP_push_object_address:
2546             if (error_ptr)
2547                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_push_object_address.");
2548             return false;
2549 
2550         //----------------------------------------------------------------------
2551         // OPCODE: DW_OP_call2
2552         // OPERANDS:
2553         //      uint16_t compile unit relative offset of a DIE
2554         // DESCRIPTION: Performs subroutine calls during evaluation
2555         // of a DWARF expression. The operand is the 2-byte unsigned offset
2556         // of a debugging information entry in the current compilation unit.
2557         //
2558         // Operand interpretation is exactly like that for DW_FORM_ref2.
2559         //
2560         // This operation transfers control of DWARF expression evaluation
2561         // to the DW_AT_location attribute of the referenced DIE. If there is
2562         // no such attribute, then there is no effect. Execution of the DWARF
2563         // expression of a DW_AT_location attribute may add to and/or remove from
2564         // values on the stack. Execution returns to the point following the call
2565         // when the end of the attribute is reached. Values on the stack at the
2566         // time of the call may be used as parameters by the called expression
2567         // and values left on the stack by the called expression may be used as
2568         // return values by prior agreement between the calling and called
2569         // expressions.
2570         //----------------------------------------------------------------------
2571         case DW_OP_call2:
2572             if (error_ptr)
2573                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call2.");
2574             return false;
2575         //----------------------------------------------------------------------
2576         // OPCODE: DW_OP_call4
2577         // OPERANDS: 1
2578         //      uint32_t compile unit relative offset of a DIE
2579         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2580         // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset
2581         // of a debugging information entry in  the current compilation unit.
2582         //
2583         // Operand interpretation DW_OP_call4 is exactly like that for
2584         // DW_FORM_ref4.
2585         //
2586         // This operation transfers control of DWARF expression evaluation
2587         // to the DW_AT_location attribute of the referenced DIE. If there is
2588         // no such attribute, then there is no effect. Execution of the DWARF
2589         // expression of a DW_AT_location attribute may add to and/or remove from
2590         // values on the stack. Execution returns to the point following the call
2591         // when the end of the attribute is reached. Values on the stack at the
2592         // time of the call may be used as parameters by the called expression
2593         // and values left on the stack by the called expression may be used as
2594         // return values by prior agreement between the calling and called
2595         // expressions.
2596         //----------------------------------------------------------------------
2597         case DW_OP_call4:
2598             if (error_ptr)
2599                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call4.");
2600             return false;
2601 
2602 #if 0
2603         //----------------------------------------------------------------------
2604         // OPCODE: DW_OP_call_ref
2605         // OPERANDS:
2606         //      uint32_t absolute DIE offset for 32-bit DWARF or a uint64_t
2607         //               absolute DIE offset for 64 bit DWARF.
2608         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2609         // expression. Takes a single operand. In the 32-bit DWARF format, the
2610         // operand is a 4-byte unsigned value; in the 64-bit DWARF format, it
2611         // is an 8-byte unsigned value. The operand is used as the offset of a
2612         // debugging information entry in a .debug_info section which may be
2613         // contained in a shared object for executable other than that
2614         // containing the operator. For references from one shared object or
2615         // executable to another, the relocation must be performed by the
2616         // consumer.
2617         //
2618         // Operand interpretation of DW_OP_call_ref is exactly like that for
2619         // DW_FORM_ref_addr.
2620         //
2621         // This operation transfers control of DWARF expression evaluation
2622         // to the DW_AT_location attribute of the referenced DIE. If there is
2623         // no such attribute, then there is no effect. Execution of the DWARF
2624         // expression of a DW_AT_location attribute may add to and/or remove from
2625         // values on the stack. Execution returns to the point following the call
2626         // when the end of the attribute is reached. Values on the stack at the
2627         // time of the call may be used as parameters by the called expression
2628         // and values left on the stack by the called expression may be used as
2629         // return values by prior agreement between the calling and called
2630         // expressions.
2631         //----------------------------------------------------------------------
2632         case DW_OP_call_ref:
2633             if (error_ptr)
2634                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call_ref.");
2635             return false;
2636 
2637                 //----------------------------------------------------------------------
2638                 // OPCODE: DW_OP_APPLE_array_ref
2639                 // OPERANDS: none
2640                 // DESCRIPTION: Pops a value off the stack and uses it as the array
2641                 // index.  Pops a second value off the stack and uses it as the array
2642                 // itself.  Pushes a value onto the stack representing the element of
2643                 // the array specified by the index.
2644                 //----------------------------------------------------------------------
2645             case DW_OP_APPLE_array_ref:
2646             {
2647                 if (stack.size() < 2)
2648                 {
2649                     if (error_ptr)
2650                         error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_APPLE_array_ref.");
2651                     return false;
2652                 }
2653 
2654                 Value index_val = stack.back();
2655                 stack.pop_back();
2656                 Value array_val = stack.back();
2657                 stack.pop_back();
2658 
2659                 Scalar &index_scalar = index_val.ResolveValue(exe_ctx, ast_context);
2660                 int64_t index = index_scalar.SLongLong(LLONG_MAX);
2661 
2662                 if (index == LLONG_MAX)
2663                 {
2664                     if (error_ptr)
2665                         error_ptr->SetErrorString("Invalid array index.");
2666                     return false;
2667                 }
2668 
2669                 if (array_val.GetContextType() != Value::eContextTypeClangType)
2670                 {
2671                     if (error_ptr)
2672                         error_ptr->SetErrorString("Arrays without Clang types are unhandled at this time.");
2673                     return false;
2674                 }
2675 
2676                 if (array_val.GetValueType() != Value::eValueTypeLoadAddress &&
2677                     array_val.GetValueType() != Value::eValueTypeHostAddress)
2678                 {
2679                     if (error_ptr)
2680                         error_ptr->SetErrorString("Array must be stored in memory.");
2681                     return false;
2682                 }
2683 
2684                 void *array_type = array_val.GetClangType();
2685 
2686                 void *member_type;
2687                 uint64_t size = 0;
2688 
2689                 if ((!ClangASTContext::IsPointerType(array_type, &member_type)) &&
2690                     (!ClangASTContext::IsArrayType(array_type, &member_type, &size)))
2691                 {
2692                     if (error_ptr)
2693                         error_ptr->SetErrorString("Array reference from something that is neither a pointer nor an array.");
2694                     return false;
2695                 }
2696 
2697                 if (size && (index >= size || index < 0))
2698                 {
2699                     if (error_ptr)
2700                         error_ptr->SetErrorStringWithFormat("Out of bounds array access.  %lld is not in [0, %llu]", index, size);
2701                     return false;
2702                 }
2703 
2704                 uint64_t member_bit_size = ClangASTType::GetClangTypeBitWidth(ast_context, member_type);
2705                 uint64_t member_bit_align = ClangASTType::GetTypeBitAlign(ast_context, member_type);
2706                 uint64_t member_bit_incr = ((member_bit_size + member_bit_align - 1) / member_bit_align) * member_bit_align;
2707                 if (member_bit_incr % 8)
2708                 {
2709                     if (error_ptr)
2710                         error_ptr->SetErrorStringWithFormat("Array increment is not byte aligned");
2711                     return false;
2712                 }
2713                 int64_t member_offset = (int64_t)(member_bit_incr / 8) * index;
2714 
2715                 Value member;
2716 
2717                 member.SetContext(Value::eContextTypeClangType, member_type);
2718                 member.SetValueType(array_val.GetValueType());
2719 
2720                 addr_t array_base = (addr_t)array_val.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
2721                 addr_t member_loc = array_base + member_offset;
2722                 member.GetScalar() = (uint64_t)member_loc;
2723 
2724                 stack.push_back(member);
2725             }
2726                 break;
2727 
2728         //----------------------------------------------------------------------
2729         // OPCODE: DW_OP_APPLE_uninit
2730         // OPERANDS: none
2731         // DESCRIPTION: Lets us know that the value is currently not initialized
2732         //----------------------------------------------------------------------
2733         case DW_OP_APPLE_uninit:
2734             //return eResultTypeErrorUninitialized;
2735             break;  // Ignore this as we have seen cases where this value is incorrectly added
2736 
2737         //----------------------------------------------------------------------
2738         // OPCODE: DW_OP_APPLE_assign
2739         // OPERANDS: none
2740         // DESCRIPTION: Pops a value off of the stack and assigns it to the next
2741         // item on the stack which must be something assignable (inferior
2742         // Variable, inferior Type with address, inferior register, or
2743         // expression local variable.
2744         //----------------------------------------------------------------------
2745         case DW_OP_APPLE_assign:
2746             if (stack.size() < 2)
2747             {
2748                 if (error_ptr)
2749                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_APPLE_assign.");
2750                 return false;
2751             }
2752             else
2753             {
2754                 tmp = stack.back();
2755                 stack.pop_back();
2756                 Value::ContextType context_type = stack.back().GetContextType();
2757                 StreamString new_value(Stream::eBinary, 4, lldb::endian::InlHostByteOrder());
2758                 switch (context_type)
2759                 {
2760                 case Value::eContextTypeClangType:
2761                     {
2762                         void *clang_type = stack.back().GetClangType();
2763 
2764                         if (ClangASTContext::IsAggregateType (clang_type))
2765                         {
2766                             Value::ValueType source_value_type = tmp.GetValueType();
2767                             Value::ValueType target_value_type = stack.back().GetValueType();
2768 
2769                             addr_t source_addr = (addr_t)tmp.GetScalar().ULongLong();
2770                             addr_t target_addr = (addr_t)stack.back().GetScalar().ULongLong();
2771 
2772                             size_t byte_size = (ClangASTType::GetClangTypeBitWidth(ast_context, clang_type) + 7) / 8;
2773 
2774                             switch (source_value_type)
2775                             {
2776                             case Value::eValueTypeScalar:
2777                             case Value::eValueTypeFileAddress:
2778                                 break;
2779 
2780                             case Value::eValueTypeLoadAddress:
2781                                 switch (target_value_type)
2782                                 {
2783                                 case Value::eValueTypeLoadAddress:
2784                                     {
2785                                         DataBufferHeap data;
2786                                         data.SetByteSize(byte_size);
2787 
2788                                         Error error;
2789                                         if (process->ReadMemory (source_addr, data.GetBytes(), byte_size, error) != byte_size)
2790                                         {
2791                                             if (error_ptr)
2792                                                 error_ptr->SetErrorStringWithFormat ("Couldn't read a composite type from the target: %s", error.AsCString());
2793                                             return false;
2794                                         }
2795 
2796                                         if (process->WriteMemory (target_addr, data.GetBytes(), byte_size, error) != byte_size)
2797                                         {
2798                                             if (error_ptr)
2799                                                 error_ptr->SetErrorStringWithFormat ("Couldn't write a composite type to the target: %s", error.AsCString());
2800                                             return false;
2801                                         }
2802                                     }
2803                                     break;
2804                                 case Value::eValueTypeHostAddress:
2805                                     if (process->GetByteOrder() != lldb::endian::InlHostByteOrder())
2806                                     {
2807                                         if (error_ptr)
2808                                             error_ptr->SetErrorStringWithFormat ("Copy of composite types between incompatible byte orders is unimplemented");
2809                                         return false;
2810                                     }
2811                                     else
2812                                     {
2813                                         Error error;
2814                                         if (process->ReadMemory (source_addr, (uint8_t*)target_addr, byte_size, error) != byte_size)
2815                                         {
2816                                             if (error_ptr)
2817                                                 error_ptr->SetErrorStringWithFormat ("Couldn't read a composite type from the target: %s", error.AsCString());
2818                                             return false;
2819                                         }
2820                                     }
2821                                     break;
2822                                 default:
2823                                     return false;
2824                                 }
2825                                 break;
2826                             case Value::eValueTypeHostAddress:
2827                                 switch (target_value_type)
2828                                 {
2829                                 case Value::eValueTypeLoadAddress:
2830                                     if (process->GetByteOrder() != lldb::endian::InlHostByteOrder())
2831                                     {
2832                                         if (error_ptr)
2833                                             error_ptr->SetErrorStringWithFormat ("Copy of composite types between incompatible byte orders is unimplemented");
2834                                         return false;
2835                                     }
2836                                     else
2837                                     {
2838                                         Error error;
2839                                         if (process->WriteMemory (target_addr, (uint8_t*)source_addr, byte_size, error) != byte_size)
2840                                         {
2841                                             if (error_ptr)
2842                                                 error_ptr->SetErrorStringWithFormat ("Couldn't write a composite type to the target: %s", error.AsCString());
2843                                             return false;
2844                                         }
2845                                     }
2846                                 case Value::eValueTypeHostAddress:
2847                                     memcpy ((uint8_t*)target_addr, (uint8_t*)source_addr, byte_size);
2848                                     break;
2849                                 default:
2850                                     return false;
2851                                 }
2852                             }
2853                         }
2854                         else
2855                         {
2856                             if (!ClangASTType::SetValueFromScalar (ast_context,
2857                                                                   clang_type,
2858                                                                   tmp.ResolveValue(exe_ctx, ast_context),
2859                                                                   new_value))
2860                             {
2861                                 if (error_ptr)
2862                                     error_ptr->SetErrorStringWithFormat ("Couldn't extract a value from an integral type.\n");
2863                                 return false;
2864                             }
2865 
2866                             Value::ValueType value_type = stack.back().GetValueType();
2867 
2868                             switch (value_type)
2869                             {
2870                             case Value::eValueTypeLoadAddress:
2871                             case Value::eValueTypeHostAddress:
2872                                 {
2873                                     AddressType address_type = (value_type == Value::eValueTypeLoadAddress ? eAddressTypeLoad : eAddressTypeHost);
2874                                     lldb::addr_t addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
2875                                     if (!ClangASTType::WriteToMemory (ast_context,
2876                                                                           clang_type,
2877                                                                           exe_ctx,
2878                                                                           addr,
2879                                                                           address_type,
2880                                                                           new_value))
2881                                     {
2882                                         if (error_ptr)
2883                                             error_ptr->SetErrorStringWithFormat ("Failed to write value to memory at 0x%llx.\n", addr);
2884                                         return false;
2885                                     }
2886                                 }
2887                                 break;
2888 
2889                             default:
2890                                 break;
2891                             }
2892                         }
2893                     }
2894                     break;
2895 
2896                 default:
2897                     if (error_ptr)
2898                         error_ptr->SetErrorString ("Assign failed.");
2899                     return false;
2900                 }
2901             }
2902             break;
2903 
2904         //----------------------------------------------------------------------
2905         // OPCODE: DW_OP_APPLE_address_of
2906         // OPERANDS: none
2907         // DESCRIPTION: Pops a value off of the stack and pushed its address.
2908         // The top item on the stack must be a variable, or already be a memory
2909         // location.
2910         //----------------------------------------------------------------------
2911         case DW_OP_APPLE_address_of:
2912             if (stack.empty())
2913             {
2914                 if (error_ptr)
2915                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_APPLE_address_of.");
2916                 return false;
2917             }
2918             else
2919             {
2920                 Value::ValueType value_type = stack.back().GetValueType();
2921                 switch (value_type)
2922                 {
2923                 default:
2924                 case Value::eValueTypeScalar:      // raw scalar value
2925                     if (error_ptr)
2926                         error_ptr->SetErrorString("Top stack item isn't a memory based object.");
2927                     return false;
2928 
2929                 case Value::eValueTypeLoadAddress: // load address value
2930                 case Value::eValueTypeFileAddress: // file address value
2931                 case Value::eValueTypeHostAddress: // host address value (for memory in the process that is using liblldb)
2932                     // Taking the address of an object reduces it to the address
2933                     // of the value and removes any extra context it had.
2934                     //stack.back().SetValueType(Value::eValueTypeScalar);
2935                     stack.back().ClearContext();
2936                     break;
2937                 }
2938             }
2939             break;
2940 
2941         //----------------------------------------------------------------------
2942         // OPCODE: DW_OP_APPLE_value_of
2943         // OPERANDS: none
2944         // DESCRIPTION: Pops a value off of the stack and pushed its value.
2945         // The top item on the stack must be a variable, expression variable.
2946         //----------------------------------------------------------------------
2947         case DW_OP_APPLE_value_of:
2948             if (stack.empty())
2949             {
2950                 if (error_ptr)
2951                     error_ptr->SetErrorString("Expression stack needs at least 1 items for DW_OP_APPLE_value_of.");
2952                 return false;
2953             }
2954             else if (!stack.back().ValueOf(exe_ctx, ast_context))
2955             {
2956                 if (error_ptr)
2957                     error_ptr->SetErrorString ("Top stack item isn't a valid candidate for DW_OP_APPLE_value_of.");
2958                 return false;
2959             }
2960             break;
2961 
2962         //----------------------------------------------------------------------
2963         // OPCODE: DW_OP_APPLE_deref_type
2964         // OPERANDS: none
2965         // DESCRIPTION: gets the value pointed to by the top stack item
2966         //----------------------------------------------------------------------
2967         case DW_OP_APPLE_deref_type:
2968             {
2969                 if (stack.empty())
2970                 {
2971                     if (error_ptr)
2972                         error_ptr->SetErrorString("Expression stack needs at least 1 items for DW_OP_APPLE_deref_type.");
2973                     return false;
2974                 }
2975 
2976                 tmp = stack.back();
2977                 stack.pop_back();
2978 
2979                 if (tmp.GetContextType() != Value::eContextTypeClangType)
2980                 {
2981                     if (error_ptr)
2982                         error_ptr->SetErrorString("Item at top of expression stack must have a Clang type");
2983                     return false;
2984                 }
2985 
2986                 void *ptr_type = tmp.GetClangType();
2987                 void *target_type;
2988 
2989                 if (!ClangASTContext::IsPointerType(ptr_type, &target_type))
2990                 {
2991                     if (error_ptr)
2992                         error_ptr->SetErrorString("Dereferencing a non-pointer type");
2993                     return false;
2994                 }
2995 
2996                 // TODO do we want all pointers to be dereferenced as load addresses?
2997                 Value::ValueType value_type = tmp.GetValueType();
2998 
2999                 tmp.ResolveValue(exe_ctx, ast_context);
3000 
3001                 tmp.SetValueType(value_type);
3002                 tmp.SetContext(Value::eContextTypeClangType, target_type);
3003 
3004                 stack.push_back(tmp);
3005             }
3006             break;
3007 
3008         //----------------------------------------------------------------------
3009         // OPCODE: DW_OP_APPLE_expr_local
3010         // OPERANDS: ULEB128
3011         // DESCRIPTION: pushes the expression local variable index onto the
3012         // stack and set the appropriate context so we know the stack item is
3013         // an expression local variable index.
3014         //----------------------------------------------------------------------
3015         case DW_OP_APPLE_expr_local:
3016             {
3017                 /*
3018                 uint32_t idx = opcodes.GetULEB128(&offset);
3019                 if (expr_locals == NULL)
3020                 {
3021                     if (error_ptr)
3022                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_expr_local(%u) opcode encountered with no local variable list.\n", idx);
3023                     return false;
3024                 }
3025                 Value *expr_local_variable = expr_locals->GetVariableAtIndex(idx);
3026                 if (expr_local_variable == NULL)
3027                 {
3028                     if (error_ptr)
3029                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_expr_local(%u) with invalid index %u.\n", idx, idx);
3030                     return false;
3031                 }
3032                  // The proxy code has been removed. If it is ever re-added, please
3033                  // use shared pointers or return by value to avoid possible memory
3034                  // leak (there is no leak here, but in general, no returning pointers
3035                  // that must be manually freed please.
3036                 Value *proxy = expr_local_variable->CreateProxy();
3037                 stack.push_back(*proxy);
3038                 delete proxy;
3039                 //stack.back().SetContext (Value::eContextTypeClangType, expr_local_variable->GetClangType());
3040                 */
3041             }
3042             break;
3043 
3044         //----------------------------------------------------------------------
3045         // OPCODE: DW_OP_APPLE_extern
3046         // OPERANDS: ULEB128
3047         // DESCRIPTION: pushes a proxy for the extern object index onto the
3048         // stack.
3049         //----------------------------------------------------------------------
3050         case DW_OP_APPLE_extern:
3051             {
3052                 /*
3053                 uint32_t idx = opcodes.GetULEB128(&offset);
3054                 if (!decl_map)
3055                 {
3056                     if (error_ptr)
3057                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_extern(%u) opcode encountered with no decl map.\n", idx);
3058                     return false;
3059                 }
3060                 Value *extern_var = decl_map->GetValueForIndex(idx);
3061                 if (!extern_var)
3062                 {
3063                     if (error_ptr)
3064                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_extern(%u) with invalid index %u.\n", idx, idx);
3065                     return false;
3066                 }
3067                 // The proxy code has been removed. If it is ever re-added, please
3068                 // use shared pointers or return by value to avoid possible memory
3069                 // leak (there is no leak here, but in general, no returning pointers
3070                 // that must be manually freed please.
3071                 Value *proxy = extern_var->CreateProxy();
3072                 stack.push_back(*proxy);
3073                 delete proxy;
3074                 */
3075             }
3076             break;
3077 
3078         case DW_OP_APPLE_scalar_cast:
3079             if (stack.empty())
3080             {
3081                 if (error_ptr)
3082                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_APPLE_scalar_cast.");
3083                 return false;
3084             }
3085             else
3086             {
3087                 // Simple scalar cast
3088                 if (!stack.back().ResolveValue(exe_ctx, ast_context).Cast((Scalar::Type)opcodes.GetU8(&offset)))
3089                 {
3090                     if (error_ptr)
3091                         error_ptr->SetErrorString("Cast failed.");
3092                     return false;
3093                 }
3094             }
3095             break;
3096 
3097 
3098         case DW_OP_APPLE_clang_cast:
3099             if (stack.empty())
3100             {
3101                 if (error_ptr)
3102                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_APPLE_clang_cast.");
3103                 return false;
3104             }
3105             else
3106             {
3107                 void *clang_type = (void *)opcodes.GetMaxU64(&offset, sizeof(void*));
3108                 stack.back().SetContext (Value::eContextTypeClangType, clang_type);
3109             }
3110             break;
3111         //----------------------------------------------------------------------
3112         // OPCODE: DW_OP_APPLE_constf
3113         // OPERANDS: 1 byte float length, followed by that many bytes containing
3114         // the constant float data.
3115         // DESCRIPTION: Push a float value onto the expression stack.
3116         //----------------------------------------------------------------------
3117         case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
3118             {
3119                 uint8_t float_length = opcodes.GetU8(&offset);
3120                 if (sizeof(float) == float_length)
3121                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetFloat (&offset);
3122                 else if (sizeof(double) == float_length)
3123                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetDouble (&offset);
3124                 else if (sizeof(long double) == float_length)
3125                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetLongDouble (&offset);
3126                 else
3127                 {
3128                     StreamString new_value;
3129                     opcodes.Dump(&new_value, offset, eFormatBytes, 1, float_length, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
3130 
3131                      if (error_ptr)
3132                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_constf(<%u> %s) unsupported float size.\n", float_length, new_value.GetData());
3133                     return false;
3134                }
3135                tmp.SetValueType(Value::eValueTypeScalar);
3136                tmp.ClearContext();
3137                stack.push_back(tmp);
3138             }
3139             break;
3140         //----------------------------------------------------------------------
3141         // OPCODE: DW_OP_APPLE_clear
3142         // OPERANDS: none
3143         // DESCRIPTION: Clears the expression stack.
3144         //----------------------------------------------------------------------
3145         case DW_OP_APPLE_clear:
3146             stack.clear();
3147             break;
3148 
3149         //----------------------------------------------------------------------
3150         // OPCODE: DW_OP_APPLE_error
3151         // OPERANDS: none
3152         // DESCRIPTION: Pops a value off of the stack and pushed its value.
3153         // The top item on the stack must be a variable, expression variable.
3154         //----------------------------------------------------------------------
3155         case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
3156             if (error_ptr)
3157                 error_ptr->SetErrorString ("Generic error.");
3158             return false;
3159 #endif // #if 0
3160 
3161         }
3162     }
3163 
3164     if (stack.empty())
3165     {
3166         if (error_ptr)
3167             error_ptr->SetErrorString ("Stack empty after evaluation.");
3168         return false;
3169     }
3170     else if (log && log->GetVerbose())
3171     {
3172         size_t count = stack.size();
3173         log->Printf("Stack after operation has %lu values:", count);
3174         for (size_t i=0; i<count; ++i)
3175         {
3176             StreamString new_value;
3177             new_value.Printf("[%zu]", i);
3178             stack[i].Dump(&new_value);
3179             log->Printf("  %s", new_value.GetData());
3180         }
3181     }
3182 
3183     result = stack.back();
3184     return true;    // Return true on success
3185 }
3186 
3187