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 
28 #include "lldb/lldb-private-log.h"
29 
30 #include "lldb/Symbol/ClangASTType.h"
31 #include "lldb/Symbol/ClangASTContext.h"
32 #include "lldb/Symbol/Type.h"
33 
34 #include "lldb/Target/ABI.h"
35 #include "lldb/Target/ExecutionContext.h"
36 #include "lldb/Target/Process.h"
37 #include "lldb/Target/RegisterContext.h"
38 #include "lldb/Target/StackFrame.h"
39 
40 using namespace lldb;
41 using namespace lldb_private;
42 
43 const char *
44 DW_OP_value_to_name (uint32_t val)
45 {
46   static char invalid[100];
47   switch (val) {
48     case 0x03: return "DW_OP_addr";
49     case 0x06: return "DW_OP_deref";
50     case 0x08: return "DW_OP_const1u";
51     case 0x09: return "DW_OP_const1s";
52     case 0x0a: return "DW_OP_const2u";
53     case 0x0b: return "DW_OP_const2s";
54     case 0x0c: return "DW_OP_const4u";
55     case 0x0d: return "DW_OP_const4s";
56     case 0x0e: return "DW_OP_const8u";
57     case 0x0f: return "DW_OP_const8s";
58     case 0x10: return "DW_OP_constu";
59     case 0x11: return "DW_OP_consts";
60     case 0x12: return "DW_OP_dup";
61     case 0x13: return "DW_OP_drop";
62     case 0x14: return "DW_OP_over";
63     case 0x15: return "DW_OP_pick";
64     case 0x16: return "DW_OP_swap";
65     case 0x17: return "DW_OP_rot";
66     case 0x18: return "DW_OP_xderef";
67     case 0x19: return "DW_OP_abs";
68     case 0x1a: return "DW_OP_and";
69     case 0x1b: return "DW_OP_div";
70     case 0x1c: return "DW_OP_minus";
71     case 0x1d: return "DW_OP_mod";
72     case 0x1e: return "DW_OP_mul";
73     case 0x1f: return "DW_OP_neg";
74     case 0x20: return "DW_OP_not";
75     case 0x21: return "DW_OP_or";
76     case 0x22: return "DW_OP_plus";
77     case 0x23: return "DW_OP_plus_uconst";
78     case 0x24: return "DW_OP_shl";
79     case 0x25: return "DW_OP_shr";
80     case 0x26: return "DW_OP_shra";
81     case 0x27: return "DW_OP_xor";
82     case 0x2f: return "DW_OP_skip";
83     case 0x28: return "DW_OP_bra";
84     case 0x29: return "DW_OP_eq";
85     case 0x2a: return "DW_OP_ge";
86     case 0x2b: return "DW_OP_gt";
87     case 0x2c: return "DW_OP_le";
88     case 0x2d: return "DW_OP_lt";
89     case 0x2e: return "DW_OP_ne";
90     case 0x30: return "DW_OP_lit0";
91     case 0x31: return "DW_OP_lit1";
92     case 0x32: return "DW_OP_lit2";
93     case 0x33: return "DW_OP_lit3";
94     case 0x34: return "DW_OP_lit4";
95     case 0x35: return "DW_OP_lit5";
96     case 0x36: return "DW_OP_lit6";
97     case 0x37: return "DW_OP_lit7";
98     case 0x38: return "DW_OP_lit8";
99     case 0x39: return "DW_OP_lit9";
100     case 0x3a: return "DW_OP_lit10";
101     case 0x3b: return "DW_OP_lit11";
102     case 0x3c: return "DW_OP_lit12";
103     case 0x3d: return "DW_OP_lit13";
104     case 0x3e: return "DW_OP_lit14";
105     case 0x3f: return "DW_OP_lit15";
106     case 0x40: return "DW_OP_lit16";
107     case 0x41: return "DW_OP_lit17";
108     case 0x42: return "DW_OP_lit18";
109     case 0x43: return "DW_OP_lit19";
110     case 0x44: return "DW_OP_lit20";
111     case 0x45: return "DW_OP_lit21";
112     case 0x46: return "DW_OP_lit22";
113     case 0x47: return "DW_OP_lit23";
114     case 0x48: return "DW_OP_lit24";
115     case 0x49: return "DW_OP_lit25";
116     case 0x4a: return "DW_OP_lit26";
117     case 0x4b: return "DW_OP_lit27";
118     case 0x4c: return "DW_OP_lit28";
119     case 0x4d: return "DW_OP_lit29";
120     case 0x4e: return "DW_OP_lit30";
121     case 0x4f: return "DW_OP_lit31";
122     case 0x50: return "DW_OP_reg0";
123     case 0x51: return "DW_OP_reg1";
124     case 0x52: return "DW_OP_reg2";
125     case 0x53: return "DW_OP_reg3";
126     case 0x54: return "DW_OP_reg4";
127     case 0x55: return "DW_OP_reg5";
128     case 0x56: return "DW_OP_reg6";
129     case 0x57: return "DW_OP_reg7";
130     case 0x58: return "DW_OP_reg8";
131     case 0x59: return "DW_OP_reg9";
132     case 0x5a: return "DW_OP_reg10";
133     case 0x5b: return "DW_OP_reg11";
134     case 0x5c: return "DW_OP_reg12";
135     case 0x5d: return "DW_OP_reg13";
136     case 0x5e: return "DW_OP_reg14";
137     case 0x5f: return "DW_OP_reg15";
138     case 0x60: return "DW_OP_reg16";
139     case 0x61: return "DW_OP_reg17";
140     case 0x62: return "DW_OP_reg18";
141     case 0x63: return "DW_OP_reg19";
142     case 0x64: return "DW_OP_reg20";
143     case 0x65: return "DW_OP_reg21";
144     case 0x66: return "DW_OP_reg22";
145     case 0x67: return "DW_OP_reg23";
146     case 0x68: return "DW_OP_reg24";
147     case 0x69: return "DW_OP_reg25";
148     case 0x6a: return "DW_OP_reg26";
149     case 0x6b: return "DW_OP_reg27";
150     case 0x6c: return "DW_OP_reg28";
151     case 0x6d: return "DW_OP_reg29";
152     case 0x6e: return "DW_OP_reg30";
153     case 0x6f: return "DW_OP_reg31";
154     case 0x70: return "DW_OP_breg0";
155     case 0x71: return "DW_OP_breg1";
156     case 0x72: return "DW_OP_breg2";
157     case 0x73: return "DW_OP_breg3";
158     case 0x74: return "DW_OP_breg4";
159     case 0x75: return "DW_OP_breg5";
160     case 0x76: return "DW_OP_breg6";
161     case 0x77: return "DW_OP_breg7";
162     case 0x78: return "DW_OP_breg8";
163     case 0x79: return "DW_OP_breg9";
164     case 0x7a: return "DW_OP_breg10";
165     case 0x7b: return "DW_OP_breg11";
166     case 0x7c: return "DW_OP_breg12";
167     case 0x7d: return "DW_OP_breg13";
168     case 0x7e: return "DW_OP_breg14";
169     case 0x7f: return "DW_OP_breg15";
170     case 0x80: return "DW_OP_breg16";
171     case 0x81: return "DW_OP_breg17";
172     case 0x82: return "DW_OP_breg18";
173     case 0x83: return "DW_OP_breg19";
174     case 0x84: return "DW_OP_breg20";
175     case 0x85: return "DW_OP_breg21";
176     case 0x86: return "DW_OP_breg22";
177     case 0x87: return "DW_OP_breg23";
178     case 0x88: return "DW_OP_breg24";
179     case 0x89: return "DW_OP_breg25";
180     case 0x8a: return "DW_OP_breg26";
181     case 0x8b: return "DW_OP_breg27";
182     case 0x8c: return "DW_OP_breg28";
183     case 0x8d: return "DW_OP_breg29";
184     case 0x8e: return "DW_OP_breg30";
185     case 0x8f: return "DW_OP_breg31";
186     case 0x90: return "DW_OP_regx";
187     case 0x91: return "DW_OP_fbreg";
188     case 0x92: return "DW_OP_bregx";
189     case 0x93: return "DW_OP_piece";
190     case 0x94: return "DW_OP_deref_size";
191     case 0x95: return "DW_OP_xderef_size";
192     case 0x96: return "DW_OP_nop";
193     case 0x97: return "DW_OP_push_object_address";
194     case 0x98: return "DW_OP_call2";
195     case 0x99: return "DW_OP_call4";
196     case 0x9a: return "DW_OP_call_ref";
197 //    case DW_OP_APPLE_array_ref: return "DW_OP_APPLE_array_ref";
198 //    case DW_OP_APPLE_extern: return "DW_OP_APPLE_extern";
199     case DW_OP_APPLE_uninit: return "DW_OP_APPLE_uninit";
200 //    case DW_OP_APPLE_assign: return "DW_OP_APPLE_assign";
201 //    case DW_OP_APPLE_address_of: return "DW_OP_APPLE_address_of";
202 //    case DW_OP_APPLE_value_of: return "DW_OP_APPLE_value_of";
203 //    case DW_OP_APPLE_deref_type: return "DW_OP_APPLE_deref_type";
204 //    case DW_OP_APPLE_expr_local: return "DW_OP_APPLE_expr_local";
205 //    case DW_OP_APPLE_constf: return "DW_OP_APPLE_constf";
206 //    case DW_OP_APPLE_scalar_cast: return "DW_OP_APPLE_scalar_cast";
207 //    case DW_OP_APPLE_clang_cast: return "DW_OP_APPLE_clang_cast";
208 //    case DW_OP_APPLE_clear: return "DW_OP_APPLE_clear";
209 //    case DW_OP_APPLE_error: return "DW_OP_APPLE_error";
210     default:
211        snprintf (invalid, sizeof(invalid), "Unknown DW_OP constant: 0x%x", val);
212        return invalid;
213   }
214 }
215 
216 
217 //----------------------------------------------------------------------
218 // DWARFExpression constructor
219 //----------------------------------------------------------------------
220 DWARFExpression::DWARFExpression() :
221     m_data(),
222     m_reg_kind (eRegisterKindDWARF),
223     m_loclist_slide (LLDB_INVALID_ADDRESS)
224 {
225 }
226 
227 DWARFExpression::DWARFExpression(const DWARFExpression& rhs) :
228     m_data(rhs.m_data),
229     m_reg_kind (rhs.m_reg_kind),
230     m_loclist_slide(rhs.m_loclist_slide)
231 {
232 }
233 
234 
235 DWARFExpression::DWARFExpression(const DataExtractor& data, uint32_t data_offset, uint32_t data_length) :
236     m_data(data, data_offset, data_length),
237     m_reg_kind (eRegisterKindDWARF),
238     m_loclist_slide(LLDB_INVALID_ADDRESS)
239 {
240 }
241 
242 //----------------------------------------------------------------------
243 // Destructor
244 //----------------------------------------------------------------------
245 DWARFExpression::~DWARFExpression()
246 {
247 }
248 
249 
250 bool
251 DWARFExpression::IsValid() const
252 {
253     return m_data.GetByteSize() > 0;
254 }
255 
256 void
257 DWARFExpression::SetOpcodeData (const DataExtractor& data)
258 {
259     m_data = data;
260 }
261 
262 void
263 DWARFExpression::SetOpcodeData (const DataExtractor& data, uint32_t data_offset, uint32_t data_length)
264 {
265     m_data.SetData(data, data_offset, data_length);
266 }
267 
268 void
269 DWARFExpression::DumpLocation (Stream *s, uint32_t offset, uint32_t length, lldb::DescriptionLevel level, ABI *abi) const
270 {
271     if (!m_data.ValidOffsetForDataOfSize(offset, length))
272         return;
273     const uint32_t start_offset = offset;
274     const uint32_t end_offset = offset + length;
275     while (m_data.ValidOffset(offset) && offset < end_offset)
276     {
277         const uint32_t op_offset = offset;
278         const uint8_t op = m_data.GetU8(&offset);
279 
280         switch (level)
281         {
282         default:
283             break;
284 
285         case lldb::eDescriptionLevelBrief:
286             if (offset > start_offset)
287                 s->PutChar(' ');
288             break;
289 
290         case lldb::eDescriptionLevelFull:
291         case lldb::eDescriptionLevelVerbose:
292             if (offset > start_offset)
293                 s->EOL();
294             s->Indent();
295             if (level == lldb::eDescriptionLevelFull)
296                 break;
297             // Fall through for verbose and print offset and DW_OP prefix..
298             s->Printf("0x%8.8x: %s", op_offset, op >= DW_OP_APPLE_uninit ? "DW_OP_APPLE_" : "DW_OP_");
299             break;
300         }
301 
302         switch (op)
303         {
304         case DW_OP_addr:    *s << "DW_OP_addr(" << m_data.GetAddress(&offset) << ") "; break;         // 0x03 1 address
305         case DW_OP_deref:   *s << "DW_OP_deref"; break;                                               // 0x06
306         case DW_OP_const1u: s->Printf("DW_OP_const1u(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x08 1 1-byte constant
307         case DW_OP_const1s: s->Printf("DW_OP_const1s(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x09 1 1-byte constant
308         case DW_OP_const2u: s->Printf("DW_OP_const2u(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0a 1 2-byte constant
309         case DW_OP_const2s: s->Printf("DW_OP_const2s(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0b 1 2-byte constant
310         case DW_OP_const4u: s->Printf("DW_OP_const4u(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0c 1 4-byte constant
311         case DW_OP_const4s: s->Printf("DW_OP_const4s(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0d 1 4-byte constant
312         case DW_OP_const8u: s->Printf("DW_OP_const8u(0x%16.16llx) ", m_data.GetU64(&offset)); break;  // 0x0e 1 8-byte constant
313         case DW_OP_const8s: s->Printf("DW_OP_const8s(0x%16.16llx) ", m_data.GetU64(&offset)); break;  // 0x0f 1 8-byte constant
314         case DW_OP_constu:  s->Printf("DW_OP_constu(0x%llx) ", m_data.GetULEB128(&offset)); break;    // 0x10 1 ULEB128 constant
315         case DW_OP_consts:  s->Printf("DW_OP_consts(0x%lld) ", m_data.GetSLEB128(&offset)); break;    // 0x11 1 SLEB128 constant
316         case DW_OP_dup:     s->PutCString("DW_OP_dup"); break;                                        // 0x12
317         case DW_OP_drop:    s->PutCString("DW_OP_drop"); break;                                       // 0x13
318         case DW_OP_over:    s->PutCString("DW_OP_over"); break;                                       // 0x14
319         case DW_OP_pick:    s->Printf("DW_OP_pick(0x%2.2x) ", m_data.GetU8(&offset)); break;          // 0x15 1 1-byte stack index
320         case DW_OP_swap:    s->PutCString("DW_OP_swap"); break;                                       // 0x16
321         case DW_OP_rot:     s->PutCString("DW_OP_rot"); break;                                        // 0x17
322         case DW_OP_xderef:  s->PutCString("DW_OP_xderef"); break;                                     // 0x18
323         case DW_OP_abs:     s->PutCString("DW_OP_abs"); break;                                        // 0x19
324         case DW_OP_and:     s->PutCString("DW_OP_and"); break;                                        // 0x1a
325         case DW_OP_div:     s->PutCString("DW_OP_div"); break;                                        // 0x1b
326         case DW_OP_minus:   s->PutCString("DW_OP_minus"); break;                                      // 0x1c
327         case DW_OP_mod:     s->PutCString("DW_OP_mod"); break;                                        // 0x1d
328         case DW_OP_mul:     s->PutCString("DW_OP_mul"); break;                                        // 0x1e
329         case DW_OP_neg:     s->PutCString("DW_OP_neg"); break;                                        // 0x1f
330         case DW_OP_not:     s->PutCString("DW_OP_not"); break;                                        // 0x20
331         case DW_OP_or:      s->PutCString("DW_OP_or"); break;                                         // 0x21
332         case DW_OP_plus:    s->PutCString("DW_OP_plus"); break;                                       // 0x22
333         case DW_OP_plus_uconst:                                                                 // 0x23 1 ULEB128 addend
334             s->Printf("DW_OP_plus_uconst(0x%llx) ", m_data.GetULEB128(&offset));
335             break;
336 
337         case DW_OP_shl:     s->PutCString("DW_OP_shl"); break;                                        // 0x24
338         case DW_OP_shr:     s->PutCString("DW_OP_shr"); break;                                        // 0x25
339         case DW_OP_shra:    s->PutCString("DW_OP_shra"); break;                                       // 0x26
340         case DW_OP_xor:     s->PutCString("DW_OP_xor"); break;                                        // 0x27
341         case DW_OP_skip:    s->Printf("DW_OP_skip(0x%4.4x)", m_data.GetU16(&offset)); break;          // 0x2f 1 signed 2-byte constant
342         case DW_OP_bra:     s->Printf("DW_OP_bra(0x%4.4x)", m_data.GetU16(&offset)); break;           // 0x28 1 signed 2-byte constant
343         case DW_OP_eq:      s->PutCString("DW_OP_eq"); break;                                         // 0x29
344         case DW_OP_ge:      s->PutCString("DW_OP_ge"); break;                                         // 0x2a
345         case DW_OP_gt:      s->PutCString("DW_OP_gt"); break;                                         // 0x2b
346         case DW_OP_le:      s->PutCString("DW_OP_le"); break;                                         // 0x2c
347         case DW_OP_lt:      s->PutCString("DW_OP_lt"); break;                                         // 0x2d
348         case DW_OP_ne:      s->PutCString("DW_OP_ne"); break;                                         // 0x2e
349 
350         case DW_OP_lit0:    // 0x30
351         case DW_OP_lit1:    // 0x31
352         case DW_OP_lit2:    // 0x32
353         case DW_OP_lit3:    // 0x33
354         case DW_OP_lit4:    // 0x34
355         case DW_OP_lit5:    // 0x35
356         case DW_OP_lit6:    // 0x36
357         case DW_OP_lit7:    // 0x37
358         case DW_OP_lit8:    // 0x38
359         case DW_OP_lit9:    // 0x39
360         case DW_OP_lit10:   // 0x3A
361         case DW_OP_lit11:   // 0x3B
362         case DW_OP_lit12:   // 0x3C
363         case DW_OP_lit13:   // 0x3D
364         case DW_OP_lit14:   // 0x3E
365         case DW_OP_lit15:   // 0x3F
366         case DW_OP_lit16:   // 0x40
367         case DW_OP_lit17:   // 0x41
368         case DW_OP_lit18:   // 0x42
369         case DW_OP_lit19:   // 0x43
370         case DW_OP_lit20:   // 0x44
371         case DW_OP_lit21:   // 0x45
372         case DW_OP_lit22:   // 0x46
373         case DW_OP_lit23:   // 0x47
374         case DW_OP_lit24:   // 0x48
375         case DW_OP_lit25:   // 0x49
376         case DW_OP_lit26:   // 0x4A
377         case DW_OP_lit27:   // 0x4B
378         case DW_OP_lit28:   // 0x4C
379         case DW_OP_lit29:   // 0x4D
380         case DW_OP_lit30:   // 0x4E
381         case DW_OP_lit31:   s->Printf("DW_OP_lit%i", op - DW_OP_lit0); break; // 0x4f
382 
383         case DW_OP_reg0:    // 0x50
384         case DW_OP_reg1:    // 0x51
385         case DW_OP_reg2:    // 0x52
386         case DW_OP_reg3:    // 0x53
387         case DW_OP_reg4:    // 0x54
388         case DW_OP_reg5:    // 0x55
389         case DW_OP_reg6:    // 0x56
390         case DW_OP_reg7:    // 0x57
391         case DW_OP_reg8:    // 0x58
392         case DW_OP_reg9:    // 0x59
393         case DW_OP_reg10:   // 0x5A
394         case DW_OP_reg11:   // 0x5B
395         case DW_OP_reg12:   // 0x5C
396         case DW_OP_reg13:   // 0x5D
397         case DW_OP_reg14:   // 0x5E
398         case DW_OP_reg15:   // 0x5F
399         case DW_OP_reg16:   // 0x60
400         case DW_OP_reg17:   // 0x61
401         case DW_OP_reg18:   // 0x62
402         case DW_OP_reg19:   // 0x63
403         case DW_OP_reg20:   // 0x64
404         case DW_OP_reg21:   // 0x65
405         case DW_OP_reg22:   // 0x66
406         case DW_OP_reg23:   // 0x67
407         case DW_OP_reg24:   // 0x68
408         case DW_OP_reg25:   // 0x69
409         case DW_OP_reg26:   // 0x6A
410         case DW_OP_reg27:   // 0x6B
411         case DW_OP_reg28:   // 0x6C
412         case DW_OP_reg29:   // 0x6D
413         case DW_OP_reg30:   // 0x6E
414         case DW_OP_reg31:   // 0x6F
415             {
416                 uint32_t reg_num = op - DW_OP_reg0;
417                 if (abi)
418                 {
419                     RegisterInfo reg_info;
420                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
421                     {
422                         if (reg_info.name)
423                         {
424                             s->PutCString (reg_info.name);
425                             break;
426                         }
427                         else if (reg_info.alt_name)
428                         {
429                             s->PutCString (reg_info.alt_name);
430                             break;
431                         }
432                     }
433                 }
434                 s->Printf("DW_OP_reg%u", reg_num); break;
435             }
436             break;
437 
438         case DW_OP_breg0:
439         case DW_OP_breg1:
440         case DW_OP_breg2:
441         case DW_OP_breg3:
442         case DW_OP_breg4:
443         case DW_OP_breg5:
444         case DW_OP_breg6:
445         case DW_OP_breg7:
446         case DW_OP_breg8:
447         case DW_OP_breg9:
448         case DW_OP_breg10:
449         case DW_OP_breg11:
450         case DW_OP_breg12:
451         case DW_OP_breg13:
452         case DW_OP_breg14:
453         case DW_OP_breg15:
454         case DW_OP_breg16:
455         case DW_OP_breg17:
456         case DW_OP_breg18:
457         case DW_OP_breg19:
458         case DW_OP_breg20:
459         case DW_OP_breg21:
460         case DW_OP_breg22:
461         case DW_OP_breg23:
462         case DW_OP_breg24:
463         case DW_OP_breg25:
464         case DW_OP_breg26:
465         case DW_OP_breg27:
466         case DW_OP_breg28:
467         case DW_OP_breg29:
468         case DW_OP_breg30:
469         case DW_OP_breg31:
470             {
471                 uint32_t reg_num = op - DW_OP_breg0;
472                 int64_t reg_offset = m_data.GetSLEB128(&offset);
473                 if (abi)
474                 {
475                     RegisterInfo reg_info;
476                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
477                     {
478                         if (reg_info.name)
479                         {
480                             s->Printf("[%s%+lli]", reg_info.name, reg_offset);
481                             break;
482                         }
483                         else if (reg_info.alt_name)
484                         {
485                             s->Printf("[%s%+lli]", reg_info.alt_name, reg_offset);
486                             break;
487                         }
488                     }
489                 }
490                 s->Printf("DW_OP_breg%i(0x%llx)", reg_num, reg_offset);
491             }
492             break;
493 
494         case DW_OP_regx:                                                    // 0x90 1 ULEB128 register
495             {
496                 uint64_t reg_num = m_data.GetULEB128(&offset);
497                 if (abi)
498                 {
499                     RegisterInfo reg_info;
500                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
501                     {
502                         if (reg_info.name)
503                         {
504                             s->PutCString (reg_info.name);
505                             break;
506                         }
507                         else if (reg_info.alt_name)
508                         {
509                             s->PutCString (reg_info.alt_name);
510                             break;
511                         }
512                     }
513                 }
514                 s->Printf("DW_OP_regx(%llu)", reg_num); break;
515             }
516             break;
517         case DW_OP_fbreg:                                                   // 0x91 1 SLEB128 offset
518             s->Printf("DW_OP_fbreg(%lli)",m_data.GetSLEB128(&offset));
519             break;
520         case DW_OP_bregx:                                                   // 0x92 2 ULEB128 register followed by SLEB128 offset
521             {
522                 uint32_t reg_num = m_data.GetULEB128(&offset);
523                 int64_t reg_offset = m_data.GetSLEB128(&offset);
524                 if (abi)
525                 {
526                     RegisterInfo reg_info;
527                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
528                     {
529                         if (reg_info.name)
530                         {
531                             s->Printf("[%s%+lli]", reg_info.name, reg_offset);
532                             break;
533                         }
534                         else if (reg_info.alt_name)
535                         {
536                             s->Printf("[%s%+lli]", reg_info.alt_name, reg_offset);
537                             break;
538                         }
539                     }
540                 }
541                 s->Printf("DW_OP_bregx(reg=%u,offset=%lli)", reg_num, reg_offset);
542             }
543             break;
544         case DW_OP_piece:                                                   // 0x93 1 ULEB128 size of piece addressed
545             s->Printf("DW_OP_piece(0x%llx)", m_data.GetULEB128(&offset));
546             break;
547         case DW_OP_deref_size:                                              // 0x94 1 1-byte size of data retrieved
548             s->Printf("DW_OP_deref_size(0x%2.2x)", m_data.GetU8(&offset));
549             break;
550         case DW_OP_xderef_size:                                             // 0x95 1 1-byte size of data retrieved
551             s->Printf("DW_OP_xderef_size(0x%2.2x)", m_data.GetU8(&offset));
552             break;
553         case DW_OP_nop: s->PutCString("DW_OP_nop"); break;                                    // 0x96
554         case DW_OP_push_object_address: s->PutCString("DW_OP_push_object_address"); break;    // 0x97 DWARF3
555         case DW_OP_call2:                                                   // 0x98 DWARF3 1 2-byte offset of DIE
556             s->Printf("DW_OP_call2(0x%4.4x)", m_data.GetU16(&offset));
557             break;
558         case DW_OP_call4:                                                   // 0x99 DWARF3 1 4-byte offset of DIE
559             s->Printf("DW_OP_call4(0x%8.8x)", m_data.GetU32(&offset));
560             break;
561         case DW_OP_call_ref:                                                // 0x9a DWARF3 1 4- or 8-byte offset of DIE
562             s->Printf("DW_OP_call_ref(0x%8.8llx)", m_data.GetAddress(&offset));
563             break;
564 //      case DW_OP_form_tls_address: s << "form_tls_address"; break;        // 0x9b DWARF3
565 //      case DW_OP_call_frame_cfa: s << "call_frame_cfa"; break;            // 0x9c DWARF3
566 //      case DW_OP_bit_piece:                                               // 0x9d DWARF3 2
567 //          s->Printf("DW_OP_bit_piece(0x%x, 0x%x)", m_data.GetULEB128(&offset), m_data.GetULEB128(&offset));
568 //          break;
569 //      case DW_OP_lo_user:     s->PutCString("DW_OP_lo_user"); break;                        // 0xe0
570 //      case DW_OP_hi_user:     s->PutCString("DW_OP_hi_user"); break;                        // 0xff
571 //        case DW_OP_APPLE_extern:
572 //            s->Printf("DW_OP_APPLE_extern(%llu)", m_data.GetULEB128(&offset));
573 //            break;
574 //        case DW_OP_APPLE_array_ref:
575 //            s->PutCString("DW_OP_APPLE_array_ref");
576 //            break;
577         case DW_OP_APPLE_uninit:
578             s->PutCString("DW_OP_APPLE_uninit");  // 0xF0
579             break;
580 //        case DW_OP_APPLE_assign:        // 0xF1 - pops value off and assigns it to second item on stack (2nd item must have assignable context)
581 //            s->PutCString("DW_OP_APPLE_assign");
582 //            break;
583 //        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)
584 //            s->PutCString("DW_OP_APPLE_address_of");
585 //            break;
586 //        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)
587 //            s->PutCString("DW_OP_APPLE_value_of");
588 //            break;
589 //        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)
590 //            s->PutCString("DW_OP_APPLE_deref_type");
591 //            break;
592 //        case DW_OP_APPLE_expr_local:    // 0xF5 - ULEB128 expression local index
593 //            s->Printf("DW_OP_APPLE_expr_local(%llu)", m_data.GetULEB128(&offset));
594 //            break;
595 //        case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
596 //            {
597 //                uint8_t float_length = m_data.GetU8(&offset);
598 //                s->Printf("DW_OP_APPLE_constf(<%u> ", float_length);
599 //                m_data.Dump(s, offset, eFormatHex, float_length, 1, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
600 //                s->PutChar(')');
601 //                // Consume the float data
602 //                m_data.GetData(&offset, float_length);
603 //            }
604 //            break;
605 //        case DW_OP_APPLE_scalar_cast:
606 //            s->Printf("DW_OP_APPLE_scalar_cast(%s)", Scalar::GetValueTypeAsCString ((Scalar::Type)m_data.GetU8(&offset)));
607 //            break;
608 //        case DW_OP_APPLE_clang_cast:
609 //            {
610 //                clang::Type *clang_type = (clang::Type *)m_data.GetMaxU64(&offset, sizeof(void*));
611 //                s->Printf("DW_OP_APPLE_clang_cast(%p)", clang_type);
612 //            }
613 //            break;
614 //        case DW_OP_APPLE_clear:
615 //            s->PutCString("DW_OP_APPLE_clear");
616 //            break;
617 //        case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
618 //            s->PutCString("DW_OP_APPLE_error");
619 //            break;
620         }
621     }
622 }
623 
624 void
625 DWARFExpression::SetLocationListSlide (addr_t slide)
626 {
627     m_loclist_slide = slide;
628 }
629 
630 int
631 DWARFExpression::GetRegisterKind ()
632 {
633     return m_reg_kind;
634 }
635 
636 void
637 DWARFExpression::SetRegisterKind (RegisterKind reg_kind)
638 {
639     m_reg_kind = reg_kind;
640 }
641 
642 bool
643 DWARFExpression::IsLocationList() const
644 {
645     return m_loclist_slide != LLDB_INVALID_ADDRESS;
646 }
647 
648 void
649 DWARFExpression::GetDescription (Stream *s, lldb::DescriptionLevel level, addr_t location_list_base_addr, ABI *abi) const
650 {
651     if (IsLocationList())
652     {
653         // We have a location list
654         uint32_t offset = 0;
655         uint32_t count = 0;
656         addr_t curr_base_addr = location_list_base_addr;
657         while (m_data.ValidOffset(offset))
658         {
659             lldb::addr_t begin_addr_offset = m_data.GetAddress(&offset);
660             lldb::addr_t end_addr_offset = m_data.GetAddress(&offset);
661             if (begin_addr_offset < end_addr_offset)
662             {
663                 if (count > 0)
664                     s->PutCString(", ");
665                 VMRange addr_range(curr_base_addr + begin_addr_offset, curr_base_addr + end_addr_offset);
666                 addr_range.Dump(s, 0, 8);
667                 s->PutChar('{');
668                 uint32_t location_length = m_data.GetU16(&offset);
669                 DumpLocation (s, offset, location_length, level, abi);
670                 s->PutChar('}');
671                 offset += location_length;
672             }
673             else if (begin_addr_offset == 0 && end_addr_offset == 0)
674             {
675                 // The end of the location list is marked by both the start and end offset being zero
676                 break;
677             }
678             else
679             {
680                 if ((m_data.GetAddressByteSize() == 4 && (begin_addr_offset == UINT32_MAX)) ||
681                     (m_data.GetAddressByteSize() == 8 && (begin_addr_offset == UINT64_MAX)))
682                 {
683                     curr_base_addr = end_addr_offset + location_list_base_addr;
684                     // We have a new base address
685                     if (count > 0)
686                         s->PutCString(", ");
687                     *s << "base_addr = " << end_addr_offset;
688                 }
689             }
690 
691             count++;
692         }
693     }
694     else
695     {
696         // We have a normal location that contains DW_OP location opcodes
697         DumpLocation (s, 0, m_data.GetByteSize(), level, abi);
698     }
699 }
700 
701 static bool
702 ReadRegisterValueAsScalar
703 (
704     RegisterContext *reg_ctx,
705     uint32_t reg_kind,
706     uint32_t reg_num,
707     Error *error_ptr,
708     Value &value
709 )
710 {
711     if (reg_ctx == NULL)
712     {
713         if (error_ptr)
714             error_ptr->SetErrorStringWithFormat("No register context in frame.\n");
715     }
716     else
717     {
718         uint32_t native_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
719         if (native_reg == LLDB_INVALID_REGNUM)
720         {
721             if (error_ptr)
722                 error_ptr->SetErrorStringWithFormat("Unable to convert register kind=%u reg_num=%u to a native register number.\n", reg_kind, reg_num);
723         }
724         else
725         {
726             const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(native_reg);
727             RegisterValue reg_value;
728             if (reg_ctx->ReadRegister (reg_info, reg_value))
729             {
730                 if (reg_value.GetScalarValue(value.GetScalar()))
731                 {
732                     value.SetValueType (Value::eValueTypeScalar);
733                     value.SetContext (Value::eContextTypeRegisterInfo,
734                                       const_cast<RegisterInfo *>(reg_info));
735                     if (error_ptr)
736                         error_ptr->Clear();
737                     return true;
738                 }
739                 else
740                 {
741                     // If we get this error, then we need to implement a value
742                     // buffer in the dwarf expression evaluation function...
743                     if (error_ptr)
744                         error_ptr->SetErrorStringWithFormat ("register %s can't be converted to a scalar value",
745                                                              reg_info->name);
746                 }
747             }
748             else
749             {
750                 if (error_ptr)
751                     error_ptr->SetErrorStringWithFormat("register %s is not available", reg_info->name);
752             }
753         }
754     }
755     return false;
756 }
757 
758 //bool
759 //DWARFExpression::LocationListContainsLoadAddress (Process* process, const Address &addr) const
760 //{
761 //    return LocationListContainsLoadAddress(process, addr.GetLoadAddress(process));
762 //}
763 //
764 //bool
765 //DWARFExpression::LocationListContainsLoadAddress (Process* process, addr_t load_addr) const
766 //{
767 //    if (load_addr == LLDB_INVALID_ADDRESS)
768 //        return false;
769 //
770 //    if (IsLocationList())
771 //    {
772 //        uint32_t offset = 0;
773 //
774 //        addr_t loc_list_base_addr = m_loclist_slide.GetLoadAddress(process);
775 //
776 //        if (loc_list_base_addr == LLDB_INVALID_ADDRESS)
777 //            return false;
778 //
779 //        while (m_data.ValidOffset(offset))
780 //        {
781 //            // We need to figure out what the value is for the location.
782 //            addr_t lo_pc = m_data.GetAddress(&offset);
783 //            addr_t hi_pc = m_data.GetAddress(&offset);
784 //            if (lo_pc == 0 && hi_pc == 0)
785 //                break;
786 //            else
787 //            {
788 //                lo_pc += loc_list_base_addr;
789 //                hi_pc += loc_list_base_addr;
790 //
791 //                if (lo_pc <= load_addr && load_addr < hi_pc)
792 //                    return true;
793 //
794 //                offset += m_data.GetU16(&offset);
795 //            }
796 //        }
797 //    }
798 //    return false;
799 //}
800 
801 static uint32_t
802 GetOpcodeDataSize (const DataExtractor &data, const uint32_t data_offset, const uint8_t op)
803 {
804     uint32_t offset = data_offset;
805     switch (op)
806     {
807         case DW_OP_addr:
808         case DW_OP_call_ref:    // 0x9a 1 address sized offset of DIE (DWARF3)
809             return data.GetAddressByteSize();
810 
811         // Opcodes with no arguments
812         case DW_OP_deref:   // 0x06
813         case DW_OP_dup:     // 0x12
814         case DW_OP_drop:    // 0x13
815         case DW_OP_over:    // 0x14
816         case DW_OP_swap:    // 0x16
817         case DW_OP_rot:     // 0x17
818         case DW_OP_xderef:  // 0x18
819         case DW_OP_abs:     // 0x19
820         case DW_OP_and:     // 0x1a
821         case DW_OP_div:     // 0x1b
822         case DW_OP_minus:   // 0x1c
823         case DW_OP_mod:     // 0x1d
824         case DW_OP_mul:     // 0x1e
825         case DW_OP_neg:     // 0x1f
826         case DW_OP_not:     // 0x20
827         case DW_OP_or:      // 0x21
828         case DW_OP_plus:    // 0x22
829         case DW_OP_shl:     // 0x24
830         case DW_OP_shr:     // 0x25
831         case DW_OP_shra:    // 0x26
832         case DW_OP_xor:     // 0x27
833         case DW_OP_eq:      // 0x29
834         case DW_OP_ge:      // 0x2a
835         case DW_OP_gt:      // 0x2b
836         case DW_OP_le:      // 0x2c
837         case DW_OP_lt:      // 0x2d
838         case DW_OP_ne:      // 0x2e
839         case DW_OP_lit0:    // 0x30
840         case DW_OP_lit1:    // 0x31
841         case DW_OP_lit2:    // 0x32
842         case DW_OP_lit3:    // 0x33
843         case DW_OP_lit4:    // 0x34
844         case DW_OP_lit5:    // 0x35
845         case DW_OP_lit6:    // 0x36
846         case DW_OP_lit7:    // 0x37
847         case DW_OP_lit8:    // 0x38
848         case DW_OP_lit9:    // 0x39
849         case DW_OP_lit10:   // 0x3A
850         case DW_OP_lit11:   // 0x3B
851         case DW_OP_lit12:   // 0x3C
852         case DW_OP_lit13:   // 0x3D
853         case DW_OP_lit14:   // 0x3E
854         case DW_OP_lit15:   // 0x3F
855         case DW_OP_lit16:   // 0x40
856         case DW_OP_lit17:   // 0x41
857         case DW_OP_lit18:   // 0x42
858         case DW_OP_lit19:   // 0x43
859         case DW_OP_lit20:   // 0x44
860         case DW_OP_lit21:   // 0x45
861         case DW_OP_lit22:   // 0x46
862         case DW_OP_lit23:   // 0x47
863         case DW_OP_lit24:   // 0x48
864         case DW_OP_lit25:   // 0x49
865         case DW_OP_lit26:   // 0x4A
866         case DW_OP_lit27:   // 0x4B
867         case DW_OP_lit28:   // 0x4C
868         case DW_OP_lit29:   // 0x4D
869         case DW_OP_lit30:   // 0x4E
870         case DW_OP_lit31:   // 0x4f
871         case DW_OP_reg0:    // 0x50
872         case DW_OP_reg1:    // 0x51
873         case DW_OP_reg2:    // 0x52
874         case DW_OP_reg3:    // 0x53
875         case DW_OP_reg4:    // 0x54
876         case DW_OP_reg5:    // 0x55
877         case DW_OP_reg6:    // 0x56
878         case DW_OP_reg7:    // 0x57
879         case DW_OP_reg8:    // 0x58
880         case DW_OP_reg9:    // 0x59
881         case DW_OP_reg10:   // 0x5A
882         case DW_OP_reg11:   // 0x5B
883         case DW_OP_reg12:   // 0x5C
884         case DW_OP_reg13:   // 0x5D
885         case DW_OP_reg14:   // 0x5E
886         case DW_OP_reg15:   // 0x5F
887         case DW_OP_reg16:   // 0x60
888         case DW_OP_reg17:   // 0x61
889         case DW_OP_reg18:   // 0x62
890         case DW_OP_reg19:   // 0x63
891         case DW_OP_reg20:   // 0x64
892         case DW_OP_reg21:   // 0x65
893         case DW_OP_reg22:   // 0x66
894         case DW_OP_reg23:   // 0x67
895         case DW_OP_reg24:   // 0x68
896         case DW_OP_reg25:   // 0x69
897         case DW_OP_reg26:   // 0x6A
898         case DW_OP_reg27:   // 0x6B
899         case DW_OP_reg28:   // 0x6C
900         case DW_OP_reg29:   // 0x6D
901         case DW_OP_reg30:   // 0x6E
902         case DW_OP_reg31:   // 0x6F
903         case DW_OP_nop:     // 0x96
904         case DW_OP_push_object_address: // 0x97 DWARF3
905         case DW_OP_form_tls_address:    // 0x9b DWARF3
906         case DW_OP_call_frame_cfa:      // 0x9c DWARF3
907             return 0;
908 
909         // Opcodes with a single 1 byte arguments
910         case DW_OP_const1u:     // 0x08 1 1-byte constant
911         case DW_OP_const1s:     // 0x09 1 1-byte constant
912         case DW_OP_pick:        // 0x15 1 1-byte stack index
913         case DW_OP_deref_size:  // 0x94 1 1-byte size of data retrieved
914         case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
915             return 1;
916 
917         // Opcodes with a single 2 byte arguments
918         case DW_OP_const2u:     // 0x0a 1 2-byte constant
919         case DW_OP_const2s:     // 0x0b 1 2-byte constant
920         case DW_OP_skip:        // 0x2f 1 signed 2-byte constant
921         case DW_OP_bra:         // 0x28 1 signed 2-byte constant
922         case DW_OP_call2:       // 0x98 1 2-byte offset of DIE (DWARF3)
923             return 2;
924 
925         // Opcodes with a single 4 byte arguments
926         case DW_OP_const4u:     // 0x0c 1 4-byte constant
927         case DW_OP_const4s:     // 0x0d 1 4-byte constant
928         case DW_OP_call4:       // 0x99 1 4-byte offset of DIE (DWARF3)
929             return 4;
930 
931         // Opcodes with a single 8 byte arguments
932         case DW_OP_const8u:     // 0x0e 1 8-byte constant
933         case DW_OP_const8s:     // 0x0f 1 8-byte constant
934              return 8;
935 
936         // All opcodes that have a single ULEB (signed or unsigned) argument
937         case DW_OP_constu:      // 0x10 1 ULEB128 constant
938         case DW_OP_consts:      // 0x11 1 SLEB128 constant
939         case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
940         case DW_OP_breg0:       // 0x70 1 ULEB128 register
941         case DW_OP_breg1:       // 0x71 1 ULEB128 register
942         case DW_OP_breg2:       // 0x72 1 ULEB128 register
943         case DW_OP_breg3:       // 0x73 1 ULEB128 register
944         case DW_OP_breg4:       // 0x74 1 ULEB128 register
945         case DW_OP_breg5:       // 0x75 1 ULEB128 register
946         case DW_OP_breg6:       // 0x76 1 ULEB128 register
947         case DW_OP_breg7:       // 0x77 1 ULEB128 register
948         case DW_OP_breg8:       // 0x78 1 ULEB128 register
949         case DW_OP_breg9:       // 0x79 1 ULEB128 register
950         case DW_OP_breg10:      // 0x7a 1 ULEB128 register
951         case DW_OP_breg11:      // 0x7b 1 ULEB128 register
952         case DW_OP_breg12:      // 0x7c 1 ULEB128 register
953         case DW_OP_breg13:      // 0x7d 1 ULEB128 register
954         case DW_OP_breg14:      // 0x7e 1 ULEB128 register
955         case DW_OP_breg15:      // 0x7f 1 ULEB128 register
956         case DW_OP_breg16:      // 0x80 1 ULEB128 register
957         case DW_OP_breg17:      // 0x81 1 ULEB128 register
958         case DW_OP_breg18:      // 0x82 1 ULEB128 register
959         case DW_OP_breg19:      // 0x83 1 ULEB128 register
960         case DW_OP_breg20:      // 0x84 1 ULEB128 register
961         case DW_OP_breg21:      // 0x85 1 ULEB128 register
962         case DW_OP_breg22:      // 0x86 1 ULEB128 register
963         case DW_OP_breg23:      // 0x87 1 ULEB128 register
964         case DW_OP_breg24:      // 0x88 1 ULEB128 register
965         case DW_OP_breg25:      // 0x89 1 ULEB128 register
966         case DW_OP_breg26:      // 0x8a 1 ULEB128 register
967         case DW_OP_breg27:      // 0x8b 1 ULEB128 register
968         case DW_OP_breg28:      // 0x8c 1 ULEB128 register
969         case DW_OP_breg29:      // 0x8d 1 ULEB128 register
970         case DW_OP_breg30:      // 0x8e 1 ULEB128 register
971         case DW_OP_breg31:      // 0x8f 1 ULEB128 register
972         case DW_OP_regx:        // 0x90 1 ULEB128 register
973         case DW_OP_fbreg:       // 0x91 1 SLEB128 offset
974         case DW_OP_piece:       // 0x93 1 ULEB128 size of piece addressed
975             data.Skip_LEB128(&offset);
976             return offset - data_offset;
977 
978         // All opcodes that have a 2 ULEB (signed or unsigned) arguments
979         case DW_OP_bregx:       // 0x92 2 ULEB128 register followed by SLEB128 offset
980         case DW_OP_bit_piece:   // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
981             data.Skip_LEB128(&offset);
982             data.Skip_LEB128(&offset);
983             return offset - data_offset;
984         default:
985             assert (!"Unhandled DW_OP_XXX opcode, add support for it");
986             break;
987     }
988     return UINT32_MAX;
989 }
990 
991 bool
992 DWARFExpression::LocationContains_DW_OP_addr (lldb::addr_t file_addr) const
993 {
994     if (IsLocationList())
995         return false;
996     uint32_t offset = 0;
997     while (m_data.ValidOffset(offset))
998     {
999         const uint8_t op = m_data.GetU8(&offset);
1000 
1001         if (op == DW_OP_addr)
1002         {
1003             if (file_addr == LLDB_INVALID_ADDRESS)
1004                 return true;
1005             addr_t op_file_addr = m_data.GetAddress(&offset);
1006             if (op_file_addr == file_addr)
1007                 return true;
1008         }
1009         else
1010         {
1011             const uint32_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1012             if (op_arg_size == UINT32_MAX)
1013                 break;
1014             offset += op_arg_size;
1015         }
1016     }
1017     return false;
1018 }
1019 
1020 bool
1021 DWARFExpression::Update_DW_OP_addr (lldb::addr_t file_addr)
1022 {
1023     if (IsLocationList())
1024         return false;
1025     uint32_t offset = 0;
1026     while (m_data.ValidOffset(offset))
1027     {
1028         const uint8_t op = m_data.GetU8(&offset);
1029 
1030         if (op == DW_OP_addr)
1031         {
1032             const uint8_t addr_byte_size = m_data.GetAddressByteSize();
1033             // We have to make a copy of the data as we don't know if this
1034             // data is from a read only memory mapped buffer, so we duplicate
1035             // all of the data first, then modify it, and if all goes well,
1036             // we then replace the data for this expression
1037 
1038             // So first we copy the data into a heap buffer
1039             std::auto_ptr<DataBufferHeap> head_data_ap (new DataBufferHeap (m_data.GetDataStart(),
1040                                                                             m_data.GetByteSize()));
1041 
1042             // Make en encoder so we can write the address into the buffer using
1043             // the correct byte order (endianness)
1044             DataEncoder encoder (head_data_ap->GetBytes(),
1045                                  head_data_ap->GetByteSize(),
1046                                  m_data.GetByteOrder(),
1047                                  addr_byte_size);
1048 
1049             // Replace the address in the new buffer
1050             if (encoder.PutMaxU64 (offset, addr_byte_size, file_addr) == UINT32_MAX)
1051                 return false;
1052 
1053             // All went well, so now we can reset the data using a shared
1054             // pointer to the heap data so "m_data" will now correctly
1055             // manage the heap data.
1056             m_data.SetData (DataBufferSP (head_data_ap.release()));
1057             return true;
1058         }
1059         else
1060         {
1061             const uint32_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1062             if (op_arg_size == UINT32_MAX)
1063                 break;
1064             offset += op_arg_size;
1065         }
1066     }
1067     return false;
1068 }
1069 
1070 bool
1071 DWARFExpression::LocationListContainsAddress (lldb::addr_t loclist_base_addr, lldb::addr_t addr) const
1072 {
1073     if (addr == LLDB_INVALID_ADDRESS)
1074         return false;
1075 
1076     if (IsLocationList())
1077     {
1078         uint32_t offset = 0;
1079 
1080         if (loclist_base_addr == LLDB_INVALID_ADDRESS)
1081             return false;
1082 
1083         while (m_data.ValidOffset(offset))
1084         {
1085             // We need to figure out what the value is for the location.
1086             addr_t lo_pc = m_data.GetAddress(&offset);
1087             addr_t hi_pc = m_data.GetAddress(&offset);
1088             if (lo_pc == 0 && hi_pc == 0)
1089                 break;
1090             else
1091             {
1092                 lo_pc += loclist_base_addr - m_loclist_slide;
1093                 hi_pc += loclist_base_addr - m_loclist_slide;
1094 
1095                 if (lo_pc <= addr && addr < hi_pc)
1096                     return true;
1097 
1098                 offset += m_data.GetU16(&offset);
1099             }
1100         }
1101     }
1102     return false;
1103 }
1104 
1105 bool
1106 DWARFExpression::GetLocation (addr_t base_addr, addr_t pc, uint32_t &offset, uint32_t &length)
1107 {
1108     offset = 0;
1109     if (!IsLocationList())
1110     {
1111         length = m_data.GetByteSize();
1112         return true;
1113     }
1114 
1115     if (base_addr != LLDB_INVALID_ADDRESS && pc != LLDB_INVALID_ADDRESS)
1116     {
1117         addr_t curr_base_addr = base_addr;
1118 
1119         while (m_data.ValidOffset(offset))
1120         {
1121             // We need to figure out what the value is for the location.
1122             addr_t lo_pc = m_data.GetAddress(&offset);
1123             addr_t hi_pc = m_data.GetAddress(&offset);
1124             if (lo_pc == 0 && hi_pc == 0)
1125             {
1126                 break;
1127             }
1128             else
1129             {
1130                 lo_pc += curr_base_addr - m_loclist_slide;
1131                 hi_pc += curr_base_addr - m_loclist_slide;
1132 
1133                 length = m_data.GetU16(&offset);
1134 
1135                 if (length > 0 && lo_pc <= pc && pc < hi_pc)
1136                     return true;
1137 
1138                 offset += length;
1139             }
1140         }
1141     }
1142     offset = UINT32_MAX;
1143     length = 0;
1144     return false;
1145 }
1146 
1147 bool
1148 DWARFExpression::DumpLocationForAddress (Stream *s,
1149                                          lldb::DescriptionLevel level,
1150                                          addr_t base_addr,
1151                                          addr_t address,
1152                                          ABI *abi)
1153 {
1154     uint32_t offset = 0;
1155     uint32_t length = 0;
1156 
1157     if (GetLocation (base_addr, address, offset, length))
1158     {
1159         if (length > 0)
1160         {
1161             DumpLocation(s, offset, length, level, abi);
1162             return true;
1163         }
1164     }
1165     return false;
1166 }
1167 
1168 bool
1169 DWARFExpression::Evaluate
1170 (
1171     ExecutionContextScope *exe_scope,
1172     clang::ASTContext *ast_context,
1173     ClangExpressionVariableList *expr_locals,
1174     ClangExpressionDeclMap *decl_map,
1175     lldb::addr_t loclist_base_load_addr,
1176     const Value* initial_value_ptr,
1177     Value& result,
1178     Error *error_ptr
1179 ) const
1180 {
1181     ExecutionContext exe_ctx (exe_scope);
1182     return Evaluate(&exe_ctx, ast_context, expr_locals, decl_map, NULL, loclist_base_load_addr, initial_value_ptr, result, error_ptr);
1183 }
1184 
1185 bool
1186 DWARFExpression::Evaluate
1187 (
1188     ExecutionContext *exe_ctx,
1189     clang::ASTContext *ast_context,
1190     ClangExpressionVariableList *expr_locals,
1191     ClangExpressionDeclMap *decl_map,
1192     RegisterContext *reg_ctx,
1193     lldb::addr_t loclist_base_load_addr,
1194     const Value* initial_value_ptr,
1195     Value& result,
1196     Error *error_ptr
1197 ) const
1198 {
1199     if (IsLocationList())
1200     {
1201         uint32_t offset = 0;
1202         addr_t pc;
1203         StackFrame *frame = NULL;
1204         if (reg_ctx)
1205             pc = reg_ctx->GetPC();
1206         else
1207         {
1208             frame = exe_ctx->GetFramePtr();
1209             pc = frame->GetRegisterContext()->GetPC();
1210         }
1211 
1212         if (loclist_base_load_addr != LLDB_INVALID_ADDRESS)
1213         {
1214             if (pc == LLDB_INVALID_ADDRESS)
1215             {
1216                 if (error_ptr)
1217                     error_ptr->SetErrorString("Invalid PC in frame.");
1218                 return false;
1219             }
1220 
1221             addr_t curr_loclist_base_load_addr = loclist_base_load_addr;
1222 
1223             while (m_data.ValidOffset(offset))
1224             {
1225                 // We need to figure out what the value is for the location.
1226                 addr_t lo_pc = m_data.GetAddress(&offset);
1227                 addr_t hi_pc = m_data.GetAddress(&offset);
1228                 if (lo_pc == 0 && hi_pc == 0)
1229                 {
1230                     break;
1231                 }
1232                 else
1233                 {
1234                     lo_pc += curr_loclist_base_load_addr - m_loclist_slide;
1235                     hi_pc += curr_loclist_base_load_addr - m_loclist_slide;
1236 
1237                     uint16_t length = m_data.GetU16(&offset);
1238 
1239                     if (length > 0 && lo_pc <= pc && pc < hi_pc)
1240                     {
1241                         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);
1242                     }
1243                     offset += length;
1244                 }
1245             }
1246         }
1247         if (error_ptr)
1248             error_ptr->SetErrorString ("variable not available");
1249         return false;
1250     }
1251 
1252     // Not a location list, just a single expression.
1253     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);
1254 }
1255 
1256 
1257 
1258 bool
1259 DWARFExpression::Evaluate
1260 (
1261     ExecutionContext *exe_ctx,
1262     clang::ASTContext *ast_context,
1263     ClangExpressionVariableList *expr_locals,
1264     ClangExpressionDeclMap *decl_map,
1265     RegisterContext *reg_ctx,
1266     const DataExtractor& opcodes,
1267     const uint32_t opcodes_offset,
1268     const uint32_t opcodes_length,
1269     const uint32_t reg_kind,
1270     const Value* initial_value_ptr,
1271     Value& result,
1272     Error *error_ptr
1273 )
1274 {
1275     std::vector<Value> stack;
1276 
1277     Process *process = NULL;
1278     StackFrame *frame = NULL;
1279 
1280     if (exe_ctx)
1281     {
1282         process = exe_ctx->GetProcessPtr();
1283         frame = exe_ctx->GetFramePtr();
1284     }
1285     if (reg_ctx == NULL && frame)
1286         reg_ctx = frame->GetRegisterContext().get();
1287 
1288     if (initial_value_ptr)
1289         stack.push_back(*initial_value_ptr);
1290 
1291     uint32_t offset = opcodes_offset;
1292     const uint32_t end_offset = opcodes_offset + opcodes_length;
1293     Value tmp;
1294     uint32_t reg_num;
1295 
1296     // Make sure all of the data is available in opcodes.
1297     if (!opcodes.ValidOffsetForDataOfSize(opcodes_offset, opcodes_length))
1298     {
1299         if (error_ptr)
1300             error_ptr->SetErrorString ("Invalid offset and/or length for opcodes buffer.");
1301         return false;
1302     }
1303     LogSP log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1304 
1305 
1306     while (opcodes.ValidOffset(offset) && offset < end_offset)
1307     {
1308         const uint32_t op_offset = offset;
1309         const uint8_t op = opcodes.GetU8(&offset);
1310 
1311         if (log && log->GetVerbose())
1312         {
1313             size_t count = stack.size();
1314             log->Printf("Stack before operation has %lu values:", count);
1315             for (size_t i=0; i<count; ++i)
1316             {
1317                 StreamString new_value;
1318                 new_value.Printf("[%zu]", i);
1319                 stack[i].Dump(&new_value);
1320                 log->Printf("  %s", new_value.GetData());
1321             }
1322             log->Printf("0x%8.8x: %s", op_offset, DW_OP_value_to_name(op));
1323         }
1324         switch (op)
1325         {
1326         //----------------------------------------------------------------------
1327         // The DW_OP_addr operation has a single operand that encodes a machine
1328         // address and whose size is the size of an address on the target machine.
1329         //----------------------------------------------------------------------
1330         case DW_OP_addr:
1331             stack.push_back(Scalar(opcodes.GetAddress(&offset)));
1332             stack.back().SetValueType (Value::eValueTypeFileAddress);
1333             break;
1334 
1335         //----------------------------------------------------------------------
1336         // The DW_OP_addr_sect_offset4 is used for any location expressions in
1337         // shared libraries that have a location like:
1338         //  DW_OP_addr(0x1000)
1339         // If this address resides in a shared library, then this virtual
1340         // address won't make sense when it is evaluated in the context of a
1341         // running process where shared libraries have been slid. To account for
1342         // this, this new address type where we can store the section pointer
1343         // and a 4 byte offset.
1344         //----------------------------------------------------------------------
1345 //      case DW_OP_addr_sect_offset4:
1346 //          {
1347 //              result_type = eResultTypeFileAddress;
1348 //              lldb::Section *sect = (lldb::Section *)opcodes.GetMaxU64(&offset, sizeof(void *));
1349 //              lldb::addr_t sect_offset = opcodes.GetU32(&offset);
1350 //
1351 //              Address so_addr (sect, sect_offset);
1352 //              lldb::addr_t load_addr = so_addr.GetLoadAddress();
1353 //              if (load_addr != LLDB_INVALID_ADDRESS)
1354 //              {
1355 //                  // We successfully resolve a file address to a load
1356 //                  // address.
1357 //                  stack.push_back(load_addr);
1358 //                  break;
1359 //              }
1360 //              else
1361 //              {
1362 //                  // We were able
1363 //                  if (error_ptr)
1364 //                      error_ptr->SetErrorStringWithFormat ("Section %s in %s is not currently loaded.\n", sect->GetName().AsCString(), sect->GetModule()->GetFileSpec().GetFilename().AsCString());
1365 //                  return false;
1366 //              }
1367 //          }
1368 //          break;
1369 
1370         //----------------------------------------------------------------------
1371         // OPCODE: DW_OP_deref
1372         // OPERANDS: none
1373         // DESCRIPTION: Pops the top stack entry and treats it as an address.
1374         // The value retrieved from that address is pushed. The size of the
1375         // data retrieved from the dereferenced address is the size of an
1376         // address on the target machine.
1377         //----------------------------------------------------------------------
1378         case DW_OP_deref:
1379             {
1380                 Value::ValueType value_type = stack.back().GetValueType();
1381                 switch (value_type)
1382                 {
1383                 case Value::eValueTypeHostAddress:
1384                     {
1385                         void *src = (void *)stack.back().GetScalar().ULongLong();
1386                         intptr_t ptr;
1387                         ::memcpy (&ptr, src, sizeof(void *));
1388                         stack.back().GetScalar() = ptr;
1389                         stack.back().ClearContext();
1390                     }
1391                     break;
1392                 case Value::eValueTypeLoadAddress:
1393                     if (exe_ctx)
1394                     {
1395                         if (process)
1396                         {
1397                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1398                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1399                             uint32_t addr_size = process->GetAddressByteSize();
1400                             Error error;
1401                             if (process->ReadMemory(pointer_addr, &addr_bytes, addr_size, error) == addr_size)
1402                             {
1403                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), addr_size);
1404                                 uint32_t addr_data_offset = 0;
1405                                 stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1406                                 stack.back().ClearContext();
1407                             }
1408                             else
1409                             {
1410                                 if (error_ptr)
1411                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%llx for DW_OP_deref: %s\n",
1412                                                                          pointer_addr,
1413                                                                          error.AsCString());
1414                                 return false;
1415                             }
1416                         }
1417                         else
1418                         {
1419                             if (error_ptr)
1420                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1421                             return false;
1422                         }
1423                     }
1424                     else
1425                     {
1426                         if (error_ptr)
1427                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1428                         return false;
1429                     }
1430                     break;
1431 
1432                 default:
1433                     break;
1434                 }
1435 
1436             }
1437             break;
1438 
1439         //----------------------------------------------------------------------
1440         // OPCODE: DW_OP_deref_size
1441         // OPERANDS: 1
1442         //  1 - uint8_t that specifies the size of the data to dereference.
1443         // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
1444         // stack entry and treats it as an address. The value retrieved from that
1445         // address is pushed. In the DW_OP_deref_size operation, however, the
1446         // size in bytes of the data retrieved from the dereferenced address is
1447         // specified by the single operand. This operand is a 1-byte unsigned
1448         // integral constant whose value may not be larger than the size of an
1449         // address on the target machine. The data retrieved is zero extended
1450         // to the size of an address on the target machine before being pushed
1451         // on the expression stack.
1452         //----------------------------------------------------------------------
1453         case DW_OP_deref_size:
1454             {
1455                 uint8_t size = opcodes.GetU8(&offset);
1456                 Value::ValueType value_type = stack.back().GetValueType();
1457                 switch (value_type)
1458                 {
1459                 case Value::eValueTypeHostAddress:
1460                     {
1461                         void *src = (void *)stack.back().GetScalar().ULongLong();
1462                         intptr_t ptr;
1463                         ::memcpy (&ptr, src, sizeof(void *));
1464                         // I can't decide whether the size operand should apply to the bytes in their
1465                         // lldb-host endianness or the target endianness.. I doubt this'll ever come up
1466                         // but I'll opt for assuming big endian regardless.
1467                         switch (size)
1468                         {
1469                             case 1: ptr = ptr & 0xff; break;
1470                             case 2: ptr = ptr & 0xffff; break;
1471                             case 3: ptr = ptr & 0xffffff; break;
1472                             case 4: ptr = ptr & 0xffffffff; break;
1473                             // the casts are added to work around the case where intptr_t is a 32 bit quantity;
1474                             // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this program.
1475                             case 5: ptr = (intptr_t) ptr & 0xffffffffffULL; break;
1476                             case 6: ptr = (intptr_t) ptr & 0xffffffffffffULL; break;
1477                             case 7: ptr = (intptr_t) ptr & 0xffffffffffffffULL; break;
1478                             default: break;
1479                         }
1480                         stack.back().GetScalar() = ptr;
1481                         stack.back().ClearContext();
1482                     }
1483                     break;
1484                 case Value::eValueTypeLoadAddress:
1485                     if (exe_ctx)
1486                     {
1487                         if (process)
1488                         {
1489                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1490                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1491                             Error error;
1492                             if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) == size)
1493                             {
1494                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), size);
1495                                 uint32_t addr_data_offset = 0;
1496                                 switch (size)
1497                                 {
1498                                     case 1: stack.back().GetScalar() = addr_data.GetU8(&addr_data_offset); break;
1499                                     case 2: stack.back().GetScalar() = addr_data.GetU16(&addr_data_offset); break;
1500                                     case 4: stack.back().GetScalar() = addr_data.GetU32(&addr_data_offset); break;
1501                                     case 8: stack.back().GetScalar() = addr_data.GetU64(&addr_data_offset); break;
1502                                     default: stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1503                                 }
1504                                 stack.back().ClearContext();
1505                             }
1506                             else
1507                             {
1508                                 if (error_ptr)
1509                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%llx for DW_OP_deref: %s\n",
1510                                                                          pointer_addr,
1511                                                                          error.AsCString());
1512                                 return false;
1513                             }
1514                         }
1515                         else
1516                         {
1517                             if (error_ptr)
1518                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1519                             return false;
1520                         }
1521                     }
1522                     else
1523                     {
1524                         if (error_ptr)
1525                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1526                         return false;
1527                     }
1528                     break;
1529 
1530                 default:
1531                     break;
1532                 }
1533 
1534             }
1535             break;
1536 
1537         //----------------------------------------------------------------------
1538         // OPCODE: DW_OP_xderef_size
1539         // OPERANDS: 1
1540         //  1 - uint8_t that specifies the size of the data to dereference.
1541         // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
1542         // the top of the stack is treated as an address. The second stack
1543         // entry is treated as an "address space identifier" for those
1544         // architectures that support multiple address spaces. The top two
1545         // stack elements are popped, a data item is retrieved through an
1546         // implementation-defined address calculation and pushed as the new
1547         // stack top. In the DW_OP_xderef_size operation, however, the size in
1548         // bytes of the data retrieved from the dereferenced address is
1549         // specified by the single operand. This operand is a 1-byte unsigned
1550         // integral constant whose value may not be larger than the size of an
1551         // address on the target machine. The data retrieved is zero extended
1552         // to the size of an address on the target machine before being pushed
1553         // on the expression stack.
1554         //----------------------------------------------------------------------
1555         case DW_OP_xderef_size:
1556             if (error_ptr)
1557                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
1558             return false;
1559         //----------------------------------------------------------------------
1560         // OPCODE: DW_OP_xderef
1561         // OPERANDS: none
1562         // DESCRIPTION: Provides an extended dereference mechanism. The entry at
1563         // the top of the stack is treated as an address. The second stack entry
1564         // is treated as an "address space identifier" for those architectures
1565         // that support multiple address spaces. The top two stack elements are
1566         // popped, a data item is retrieved through an implementation-defined
1567         // address calculation and pushed as the new stack top. The size of the
1568         // data retrieved from the dereferenced address is the size of an address
1569         // on the target machine.
1570         //----------------------------------------------------------------------
1571         case DW_OP_xderef:
1572             if (error_ptr)
1573                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
1574             return false;
1575 
1576         //----------------------------------------------------------------------
1577         // All DW_OP_constXXX opcodes have a single operand as noted below:
1578         //
1579         // Opcode           Operand 1
1580         // ---------------  ----------------------------------------------------
1581         // DW_OP_const1u    1-byte unsigned integer constant
1582         // DW_OP_const1s    1-byte signed integer constant
1583         // DW_OP_const2u    2-byte unsigned integer constant
1584         // DW_OP_const2s    2-byte signed integer constant
1585         // DW_OP_const4u    4-byte unsigned integer constant
1586         // DW_OP_const4s    4-byte signed integer constant
1587         // DW_OP_const8u    8-byte unsigned integer constant
1588         // DW_OP_const8s    8-byte signed integer constant
1589         // DW_OP_constu     unsigned LEB128 integer constant
1590         // DW_OP_consts     signed LEB128 integer constant
1591         //----------------------------------------------------------------------
1592         case DW_OP_const1u             :    stack.push_back(Scalar(( uint8_t)opcodes.GetU8 (&offset))); break;
1593         case DW_OP_const1s             :    stack.push_back(Scalar((  int8_t)opcodes.GetU8 (&offset))); break;
1594         case DW_OP_const2u             :    stack.push_back(Scalar((uint16_t)opcodes.GetU16 (&offset))); break;
1595         case DW_OP_const2s             :    stack.push_back(Scalar(( int16_t)opcodes.GetU16 (&offset))); break;
1596         case DW_OP_const4u             :    stack.push_back(Scalar((uint32_t)opcodes.GetU32 (&offset))); break;
1597         case DW_OP_const4s             :    stack.push_back(Scalar(( int32_t)opcodes.GetU32 (&offset))); break;
1598         case DW_OP_const8u             :    stack.push_back(Scalar((uint64_t)opcodes.GetU64 (&offset))); break;
1599         case DW_OP_const8s             :    stack.push_back(Scalar(( int64_t)opcodes.GetU64 (&offset))); break;
1600         case DW_OP_constu              :    stack.push_back(Scalar(opcodes.GetULEB128 (&offset))); break;
1601         case DW_OP_consts              :    stack.push_back(Scalar(opcodes.GetSLEB128 (&offset))); break;
1602 
1603         //----------------------------------------------------------------------
1604         // OPCODE: DW_OP_dup
1605         // OPERANDS: none
1606         // DESCRIPTION: duplicates the value at the top of the stack
1607         //----------------------------------------------------------------------
1608         case DW_OP_dup:
1609             if (stack.empty())
1610             {
1611                 if (error_ptr)
1612                     error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
1613                 return false;
1614             }
1615             else
1616                 stack.push_back(stack.back());
1617             break;
1618 
1619         //----------------------------------------------------------------------
1620         // OPCODE: DW_OP_drop
1621         // OPERANDS: none
1622         // DESCRIPTION: pops the value at the top of the stack
1623         //----------------------------------------------------------------------
1624         case DW_OP_drop:
1625             if (stack.empty())
1626             {
1627                 if (error_ptr)
1628                     error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
1629                 return false;
1630             }
1631             else
1632                 stack.pop_back();
1633             break;
1634 
1635         //----------------------------------------------------------------------
1636         // OPCODE: DW_OP_over
1637         // OPERANDS: none
1638         // DESCRIPTION: Duplicates the entry currently second in the stack at
1639         // the top of the stack.
1640         //----------------------------------------------------------------------
1641         case DW_OP_over:
1642             if (stack.size() < 2)
1643             {
1644                 if (error_ptr)
1645                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_over.");
1646                 return false;
1647             }
1648             else
1649                 stack.push_back(stack[stack.size() - 2]);
1650             break;
1651 
1652 
1653         //----------------------------------------------------------------------
1654         // OPCODE: DW_OP_pick
1655         // OPERANDS: uint8_t index into the current stack
1656         // DESCRIPTION: The stack entry with the specified index (0 through 255,
1657         // inclusive) is pushed on the stack
1658         //----------------------------------------------------------------------
1659         case DW_OP_pick:
1660             {
1661                 uint8_t pick_idx = opcodes.GetU8(&offset);
1662                 if (pick_idx < stack.size())
1663                     stack.push_back(stack[pick_idx]);
1664                 else
1665                 {
1666                     if (error_ptr)
1667                         error_ptr->SetErrorStringWithFormat("Index %u out of range for DW_OP_pick.\n", pick_idx);
1668                     return false;
1669                 }
1670             }
1671             break;
1672 
1673         //----------------------------------------------------------------------
1674         // OPCODE: DW_OP_swap
1675         // OPERANDS: none
1676         // DESCRIPTION: swaps the top two stack entries. The entry at the top
1677         // of the stack becomes the second stack entry, and the second entry
1678         // becomes the top of the stack
1679         //----------------------------------------------------------------------
1680         case DW_OP_swap:
1681             if (stack.size() < 2)
1682             {
1683                 if (error_ptr)
1684                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_swap.");
1685                 return false;
1686             }
1687             else
1688             {
1689                 tmp = stack.back();
1690                 stack.back() = stack[stack.size() - 2];
1691                 stack[stack.size() - 2] = tmp;
1692             }
1693             break;
1694 
1695         //----------------------------------------------------------------------
1696         // OPCODE: DW_OP_rot
1697         // OPERANDS: none
1698         // DESCRIPTION: Rotates the first three stack entries. The entry at
1699         // the top of the stack becomes the third stack entry, the second
1700         // entry becomes the top of the stack, and the third entry becomes
1701         // the second entry.
1702         //----------------------------------------------------------------------
1703         case DW_OP_rot:
1704             if (stack.size() < 3)
1705             {
1706                 if (error_ptr)
1707                     error_ptr->SetErrorString("Expression stack needs at least 3 items for DW_OP_rot.");
1708                 return false;
1709             }
1710             else
1711             {
1712                 size_t last_idx = stack.size() - 1;
1713                 Value old_top = stack[last_idx];
1714                 stack[last_idx] = stack[last_idx - 1];
1715                 stack[last_idx - 1] = stack[last_idx - 2];
1716                 stack[last_idx - 2] = old_top;
1717             }
1718             break;
1719 
1720         //----------------------------------------------------------------------
1721         // OPCODE: DW_OP_abs
1722         // OPERANDS: none
1723         // DESCRIPTION: pops the top stack entry, interprets it as a signed
1724         // value and pushes its absolute value. If the absolute value can not be
1725         // represented, the result is undefined.
1726         //----------------------------------------------------------------------
1727         case DW_OP_abs:
1728             if (stack.empty())
1729             {
1730                 if (error_ptr)
1731                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_abs.");
1732                 return false;
1733             }
1734             else if (stack.back().ResolveValue(exe_ctx, ast_context).AbsoluteValue() == false)
1735             {
1736                 if (error_ptr)
1737                     error_ptr->SetErrorString("Failed to take the absolute value of the first stack item.");
1738                 return false;
1739             }
1740             break;
1741 
1742         //----------------------------------------------------------------------
1743         // OPCODE: DW_OP_and
1744         // OPERANDS: none
1745         // DESCRIPTION: pops the top two stack values, performs a bitwise and
1746         // operation on the two, and pushes the result.
1747         //----------------------------------------------------------------------
1748         case DW_OP_and:
1749             if (stack.size() < 2)
1750             {
1751                 if (error_ptr)
1752                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_and.");
1753                 return false;
1754             }
1755             else
1756             {
1757                 tmp = stack.back();
1758                 stack.pop_back();
1759                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) & tmp.ResolveValue(exe_ctx, ast_context);
1760             }
1761             break;
1762 
1763         //----------------------------------------------------------------------
1764         // OPCODE: DW_OP_div
1765         // OPERANDS: none
1766         // DESCRIPTION: pops the top two stack values, divides the former second
1767         // entry by the former top of the stack using signed division, and
1768         // pushes the result.
1769         //----------------------------------------------------------------------
1770         case DW_OP_div:
1771             if (stack.size() < 2)
1772             {
1773                 if (error_ptr)
1774                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_div.");
1775                 return false;
1776             }
1777             else
1778             {
1779                 tmp = stack.back();
1780                 if (tmp.ResolveValue(exe_ctx, ast_context).IsZero())
1781                 {
1782                     if (error_ptr)
1783                         error_ptr->SetErrorString("Divide by zero.");
1784                     return false;
1785                 }
1786                 else
1787                 {
1788                     stack.pop_back();
1789                     stack.back() = stack.back().ResolveValue(exe_ctx, ast_context) / tmp.ResolveValue(exe_ctx, ast_context);
1790                     if (!stack.back().ResolveValue(exe_ctx, ast_context).IsValid())
1791                     {
1792                         if (error_ptr)
1793                             error_ptr->SetErrorString("Divide failed.");
1794                         return false;
1795                     }
1796                 }
1797             }
1798             break;
1799 
1800         //----------------------------------------------------------------------
1801         // OPCODE: DW_OP_minus
1802         // OPERANDS: none
1803         // DESCRIPTION: pops the top two stack values, subtracts the former top
1804         // of the stack from the former second entry, and pushes the result.
1805         //----------------------------------------------------------------------
1806         case DW_OP_minus:
1807             if (stack.size() < 2)
1808             {
1809                 if (error_ptr)
1810                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_minus.");
1811                 return false;
1812             }
1813             else
1814             {
1815                 tmp = stack.back();
1816                 stack.pop_back();
1817                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) - tmp.ResolveValue(exe_ctx, ast_context);
1818             }
1819             break;
1820 
1821         //----------------------------------------------------------------------
1822         // OPCODE: DW_OP_mod
1823         // OPERANDS: none
1824         // DESCRIPTION: pops the top two stack values and pushes the result of
1825         // the calculation: former second stack entry modulo the former top of
1826         // the stack.
1827         //----------------------------------------------------------------------
1828         case DW_OP_mod:
1829             if (stack.size() < 2)
1830             {
1831                 if (error_ptr)
1832                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mod.");
1833                 return false;
1834             }
1835             else
1836             {
1837                 tmp = stack.back();
1838                 stack.pop_back();
1839                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) % tmp.ResolveValue(exe_ctx, ast_context);
1840             }
1841             break;
1842 
1843 
1844         //----------------------------------------------------------------------
1845         // OPCODE: DW_OP_mul
1846         // OPERANDS: none
1847         // DESCRIPTION: pops the top two stack entries, multiplies them
1848         // together, and pushes the result.
1849         //----------------------------------------------------------------------
1850         case DW_OP_mul:
1851             if (stack.size() < 2)
1852             {
1853                 if (error_ptr)
1854                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mul.");
1855                 return false;
1856             }
1857             else
1858             {
1859                 tmp = stack.back();
1860                 stack.pop_back();
1861                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) * tmp.ResolveValue(exe_ctx, ast_context);
1862             }
1863             break;
1864 
1865         //----------------------------------------------------------------------
1866         // OPCODE: DW_OP_neg
1867         // OPERANDS: none
1868         // DESCRIPTION: pops the top stack entry, and pushes its negation.
1869         //----------------------------------------------------------------------
1870         case DW_OP_neg:
1871             if (stack.empty())
1872             {
1873                 if (error_ptr)
1874                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_neg.");
1875                 return false;
1876             }
1877             else
1878             {
1879                 if (stack.back().ResolveValue(exe_ctx, ast_context).UnaryNegate() == false)
1880                 {
1881                     if (error_ptr)
1882                         error_ptr->SetErrorString("Unary negate failed.");
1883                     return false;
1884                 }
1885             }
1886             break;
1887 
1888         //----------------------------------------------------------------------
1889         // OPCODE: DW_OP_not
1890         // OPERANDS: none
1891         // DESCRIPTION: pops the top stack entry, and pushes its bitwise
1892         // complement
1893         //----------------------------------------------------------------------
1894         case DW_OP_not:
1895             if (stack.empty())
1896             {
1897                 if (error_ptr)
1898                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_not.");
1899                 return false;
1900             }
1901             else
1902             {
1903                 if (stack.back().ResolveValue(exe_ctx, ast_context).OnesComplement() == false)
1904                 {
1905                     if (error_ptr)
1906                         error_ptr->SetErrorString("Logical NOT failed.");
1907                     return false;
1908                 }
1909             }
1910             break;
1911 
1912         //----------------------------------------------------------------------
1913         // OPCODE: DW_OP_or
1914         // OPERANDS: none
1915         // DESCRIPTION: pops the top two stack entries, performs a bitwise or
1916         // operation on the two, and pushes the result.
1917         //----------------------------------------------------------------------
1918         case DW_OP_or:
1919             if (stack.size() < 2)
1920             {
1921                 if (error_ptr)
1922                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_or.");
1923                 return false;
1924             }
1925             else
1926             {
1927                 tmp = stack.back();
1928                 stack.pop_back();
1929                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) | tmp.ResolveValue(exe_ctx, ast_context);
1930             }
1931             break;
1932 
1933         //----------------------------------------------------------------------
1934         // OPCODE: DW_OP_plus
1935         // OPERANDS: none
1936         // DESCRIPTION: pops the top two stack entries, adds them together, and
1937         // pushes the result.
1938         //----------------------------------------------------------------------
1939         case DW_OP_plus:
1940             if (stack.size() < 2)
1941             {
1942                 if (error_ptr)
1943                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_plus.");
1944                 return false;
1945             }
1946             else
1947             {
1948                 tmp = stack.back();
1949                 stack.pop_back();
1950                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) + tmp.ResolveValue(exe_ctx, ast_context);
1951             }
1952             break;
1953 
1954         //----------------------------------------------------------------------
1955         // OPCODE: DW_OP_plus_uconst
1956         // OPERANDS: none
1957         // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
1958         // constant operand and pushes the result.
1959         //----------------------------------------------------------------------
1960         case DW_OP_plus_uconst:
1961             if (stack.empty())
1962             {
1963                 if (error_ptr)
1964                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_plus_uconst.");
1965                 return false;
1966             }
1967             else
1968             {
1969                 uint32_t uconst_value = opcodes.GetULEB128(&offset);
1970                 // Implicit conversion from a UINT to a Scalar...
1971                 stack.back().ResolveValue(exe_ctx, ast_context) += uconst_value;
1972                 if (!stack.back().ResolveValue(exe_ctx, ast_context).IsValid())
1973                 {
1974                     if (error_ptr)
1975                         error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
1976                     return false;
1977                 }
1978             }
1979             break;
1980 
1981         //----------------------------------------------------------------------
1982         // OPCODE: DW_OP_shl
1983         // OPERANDS: none
1984         // DESCRIPTION:  pops the top two stack entries, shifts the former
1985         // second entry left by the number of bits specified by the former top
1986         // of the stack, and pushes the result.
1987         //----------------------------------------------------------------------
1988         case DW_OP_shl:
1989             if (stack.size() < 2)
1990             {
1991                 if (error_ptr)
1992                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shl.");
1993                 return false;
1994             }
1995             else
1996             {
1997                 tmp = stack.back();
1998                 stack.pop_back();
1999                 stack.back().ResolveValue(exe_ctx, ast_context) <<= tmp.ResolveValue(exe_ctx, ast_context);
2000             }
2001             break;
2002 
2003         //----------------------------------------------------------------------
2004         // OPCODE: DW_OP_shr
2005         // OPERANDS: none
2006         // DESCRIPTION: pops the top two stack entries, shifts the former second
2007         // entry right logically (filling with zero bits) by the number of bits
2008         // specified by the former top of the stack, and pushes the result.
2009         //----------------------------------------------------------------------
2010         case DW_OP_shr:
2011             if (stack.size() < 2)
2012             {
2013                 if (error_ptr)
2014                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shr.");
2015                 return false;
2016             }
2017             else
2018             {
2019                 tmp = stack.back();
2020                 stack.pop_back();
2021                 if (stack.back().ResolveValue(exe_ctx, ast_context).ShiftRightLogical(tmp.ResolveValue(exe_ctx, ast_context)) == false)
2022                 {
2023                     if (error_ptr)
2024                         error_ptr->SetErrorString("DW_OP_shr failed.");
2025                     return false;
2026                 }
2027             }
2028             break;
2029 
2030         //----------------------------------------------------------------------
2031         // OPCODE: DW_OP_shra
2032         // OPERANDS: none
2033         // DESCRIPTION: pops the top two stack entries, shifts the former second
2034         // entry right arithmetically (divide the magnitude by 2, keep the same
2035         // sign for the result) by the number of bits specified by the former
2036         // top of the stack, and pushes the result.
2037         //----------------------------------------------------------------------
2038         case DW_OP_shra:
2039             if (stack.size() < 2)
2040             {
2041                 if (error_ptr)
2042                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shra.");
2043                 return false;
2044             }
2045             else
2046             {
2047                 tmp = stack.back();
2048                 stack.pop_back();
2049                 stack.back().ResolveValue(exe_ctx, ast_context) >>= tmp.ResolveValue(exe_ctx, ast_context);
2050             }
2051             break;
2052 
2053         //----------------------------------------------------------------------
2054         // OPCODE: DW_OP_xor
2055         // OPERANDS: none
2056         // DESCRIPTION: pops the top two stack entries, performs the bitwise
2057         // exclusive-or operation on the two, and pushes the result.
2058         //----------------------------------------------------------------------
2059         case DW_OP_xor:
2060             if (stack.size() < 2)
2061             {
2062                 if (error_ptr)
2063                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_xor.");
2064                 return false;
2065             }
2066             else
2067             {
2068                 tmp = stack.back();
2069                 stack.pop_back();
2070                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) ^ tmp.ResolveValue(exe_ctx, ast_context);
2071             }
2072             break;
2073 
2074 
2075         //----------------------------------------------------------------------
2076         // OPCODE: DW_OP_skip
2077         // OPERANDS: int16_t
2078         // DESCRIPTION:  An unconditional branch. Its single operand is a 2-byte
2079         // signed integer constant. The 2-byte constant is the number of bytes
2080         // of the DWARF expression to skip forward or backward from the current
2081         // operation, beginning after the 2-byte constant.
2082         //----------------------------------------------------------------------
2083         case DW_OP_skip:
2084             {
2085                 int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
2086                 uint32_t new_offset = offset + skip_offset;
2087                 if (new_offset >= opcodes_offset && new_offset < end_offset)
2088                     offset = new_offset;
2089                 else
2090                 {
2091                     if (error_ptr)
2092                         error_ptr->SetErrorString("Invalid opcode offset in DW_OP_skip.");
2093                     return false;
2094                 }
2095             }
2096             break;
2097 
2098         //----------------------------------------------------------------------
2099         // OPCODE: DW_OP_bra
2100         // OPERANDS: int16_t
2101         // DESCRIPTION: A conditional branch. Its single operand is a 2-byte
2102         // signed integer constant. This operation pops the top of stack. If
2103         // the value popped is not the constant 0, the 2-byte constant operand
2104         // is the number of bytes of the DWARF expression to skip forward or
2105         // backward from the current operation, beginning after the 2-byte
2106         // constant.
2107         //----------------------------------------------------------------------
2108         case DW_OP_bra:
2109             {
2110                 tmp = stack.back();
2111                 stack.pop_back();
2112                 int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
2113                 Scalar zero(0);
2114                 if (tmp.ResolveValue(exe_ctx, ast_context) != zero)
2115                 {
2116                     uint32_t new_offset = offset + bra_offset;
2117                     if (new_offset >= opcodes_offset && new_offset < end_offset)
2118                         offset = new_offset;
2119                     else
2120                     {
2121                         if (error_ptr)
2122                             error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
2123                         return false;
2124                     }
2125                 }
2126             }
2127             break;
2128 
2129         //----------------------------------------------------------------------
2130         // OPCODE: DW_OP_eq
2131         // OPERANDS: none
2132         // DESCRIPTION: pops the top two stack values, compares using the
2133         // equals (==) operator.
2134         // STACK RESULT: push the constant value 1 onto the stack if the result
2135         // of the operation is true or the constant value 0 if the result of the
2136         // operation is false.
2137         //----------------------------------------------------------------------
2138         case DW_OP_eq:
2139             if (stack.size() < 2)
2140             {
2141                 if (error_ptr)
2142                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_eq.");
2143                 return false;
2144             }
2145             else
2146             {
2147                 tmp = stack.back();
2148                 stack.pop_back();
2149                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) == tmp.ResolveValue(exe_ctx, ast_context);
2150             }
2151             break;
2152 
2153         //----------------------------------------------------------------------
2154         // OPCODE: DW_OP_ge
2155         // OPERANDS: none
2156         // DESCRIPTION: pops the top two stack values, compares using the
2157         // greater than or equal to (>=) operator.
2158         // STACK RESULT: push the constant value 1 onto the stack if the result
2159         // of the operation is true or the constant value 0 if the result of the
2160         // operation is false.
2161         //----------------------------------------------------------------------
2162         case DW_OP_ge:
2163             if (stack.size() < 2)
2164             {
2165                 if (error_ptr)
2166                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ge.");
2167                 return false;
2168             }
2169             else
2170             {
2171                 tmp = stack.back();
2172                 stack.pop_back();
2173                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) >= tmp.ResolveValue(exe_ctx, ast_context);
2174             }
2175             break;
2176 
2177         //----------------------------------------------------------------------
2178         // OPCODE: DW_OP_gt
2179         // OPERANDS: none
2180         // DESCRIPTION: pops the top two stack values, compares using the
2181         // greater than (>) operator.
2182         // STACK RESULT: push the constant value 1 onto the stack if the result
2183         // of the operation is true or the constant value 0 if the result of the
2184         // operation is false.
2185         //----------------------------------------------------------------------
2186         case DW_OP_gt:
2187             if (stack.size() < 2)
2188             {
2189                 if (error_ptr)
2190                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_gt.");
2191                 return false;
2192             }
2193             else
2194             {
2195                 tmp = stack.back();
2196                 stack.pop_back();
2197                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) > tmp.ResolveValue(exe_ctx, ast_context);
2198             }
2199             break;
2200 
2201         //----------------------------------------------------------------------
2202         // OPCODE: DW_OP_le
2203         // OPERANDS: none
2204         // DESCRIPTION: pops the top two stack values, compares using the
2205         // less than or equal to (<=) operator.
2206         // STACK RESULT: push the constant value 1 onto the stack if the result
2207         // of the operation is true or the constant value 0 if the result of the
2208         // operation is false.
2209         //----------------------------------------------------------------------
2210         case DW_OP_le:
2211             if (stack.size() < 2)
2212             {
2213                 if (error_ptr)
2214                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_le.");
2215                 return false;
2216             }
2217             else
2218             {
2219                 tmp = stack.back();
2220                 stack.pop_back();
2221                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) <= tmp.ResolveValue(exe_ctx, ast_context);
2222             }
2223             break;
2224 
2225         //----------------------------------------------------------------------
2226         // OPCODE: DW_OP_lt
2227         // OPERANDS: none
2228         // DESCRIPTION: pops the top two stack values, compares using the
2229         // less than (<) operator.
2230         // STACK RESULT: push the constant value 1 onto the stack if the result
2231         // of the operation is true or the constant value 0 if the result of the
2232         // operation is false.
2233         //----------------------------------------------------------------------
2234         case DW_OP_lt:
2235             if (stack.size() < 2)
2236             {
2237                 if (error_ptr)
2238                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_lt.");
2239                 return false;
2240             }
2241             else
2242             {
2243                 tmp = stack.back();
2244                 stack.pop_back();
2245                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) < tmp.ResolveValue(exe_ctx, ast_context);
2246             }
2247             break;
2248 
2249         //----------------------------------------------------------------------
2250         // OPCODE: DW_OP_ne
2251         // OPERANDS: none
2252         // DESCRIPTION: pops the top two stack values, compares using the
2253         // not equal (!=) operator.
2254         // STACK RESULT: push the constant value 1 onto the stack if the result
2255         // of the operation is true or the constant value 0 if the result of the
2256         // operation is false.
2257         //----------------------------------------------------------------------
2258         case DW_OP_ne:
2259             if (stack.size() < 2)
2260             {
2261                 if (error_ptr)
2262                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ne.");
2263                 return false;
2264             }
2265             else
2266             {
2267                 tmp = stack.back();
2268                 stack.pop_back();
2269                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) != tmp.ResolveValue(exe_ctx, ast_context);
2270             }
2271             break;
2272 
2273         //----------------------------------------------------------------------
2274         // OPCODE: DW_OP_litn
2275         // OPERANDS: none
2276         // DESCRIPTION: encode the unsigned literal values from 0 through 31.
2277         // STACK RESULT: push the unsigned literal constant value onto the top
2278         // of the stack.
2279         //----------------------------------------------------------------------
2280         case DW_OP_lit0:
2281         case DW_OP_lit1:
2282         case DW_OP_lit2:
2283         case DW_OP_lit3:
2284         case DW_OP_lit4:
2285         case DW_OP_lit5:
2286         case DW_OP_lit6:
2287         case DW_OP_lit7:
2288         case DW_OP_lit8:
2289         case DW_OP_lit9:
2290         case DW_OP_lit10:
2291         case DW_OP_lit11:
2292         case DW_OP_lit12:
2293         case DW_OP_lit13:
2294         case DW_OP_lit14:
2295         case DW_OP_lit15:
2296         case DW_OP_lit16:
2297         case DW_OP_lit17:
2298         case DW_OP_lit18:
2299         case DW_OP_lit19:
2300         case DW_OP_lit20:
2301         case DW_OP_lit21:
2302         case DW_OP_lit22:
2303         case DW_OP_lit23:
2304         case DW_OP_lit24:
2305         case DW_OP_lit25:
2306         case DW_OP_lit26:
2307         case DW_OP_lit27:
2308         case DW_OP_lit28:
2309         case DW_OP_lit29:
2310         case DW_OP_lit30:
2311         case DW_OP_lit31:
2312             stack.push_back(Scalar(op - DW_OP_lit0));
2313             break;
2314 
2315         //----------------------------------------------------------------------
2316         // OPCODE: DW_OP_regN
2317         // OPERANDS: none
2318         // DESCRIPTION: Push the value in register n on the top of the stack.
2319         //----------------------------------------------------------------------
2320         case DW_OP_reg0:
2321         case DW_OP_reg1:
2322         case DW_OP_reg2:
2323         case DW_OP_reg3:
2324         case DW_OP_reg4:
2325         case DW_OP_reg5:
2326         case DW_OP_reg6:
2327         case DW_OP_reg7:
2328         case DW_OP_reg8:
2329         case DW_OP_reg9:
2330         case DW_OP_reg10:
2331         case DW_OP_reg11:
2332         case DW_OP_reg12:
2333         case DW_OP_reg13:
2334         case DW_OP_reg14:
2335         case DW_OP_reg15:
2336         case DW_OP_reg16:
2337         case DW_OP_reg17:
2338         case DW_OP_reg18:
2339         case DW_OP_reg19:
2340         case DW_OP_reg20:
2341         case DW_OP_reg21:
2342         case DW_OP_reg22:
2343         case DW_OP_reg23:
2344         case DW_OP_reg24:
2345         case DW_OP_reg25:
2346         case DW_OP_reg26:
2347         case DW_OP_reg27:
2348         case DW_OP_reg28:
2349         case DW_OP_reg29:
2350         case DW_OP_reg30:
2351         case DW_OP_reg31:
2352             {
2353                 reg_num = op - DW_OP_reg0;
2354 
2355                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2356                     stack.push_back(tmp);
2357                 else
2358                     return false;
2359             }
2360             break;
2361         //----------------------------------------------------------------------
2362         // OPCODE: DW_OP_regx
2363         // OPERANDS:
2364         //      ULEB128 literal operand that encodes the register.
2365         // DESCRIPTION: Push the value in register on the top of the stack.
2366         //----------------------------------------------------------------------
2367         case DW_OP_regx:
2368             {
2369                 reg_num = opcodes.GetULEB128(&offset);
2370                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2371                     stack.push_back(tmp);
2372                 else
2373                     return false;
2374             }
2375             break;
2376 
2377         //----------------------------------------------------------------------
2378         // OPCODE: DW_OP_bregN
2379         // OPERANDS:
2380         //      SLEB128 offset from register N
2381         // DESCRIPTION: Value is in memory at the address specified by register
2382         // N plus an offset.
2383         //----------------------------------------------------------------------
2384         case DW_OP_breg0:
2385         case DW_OP_breg1:
2386         case DW_OP_breg2:
2387         case DW_OP_breg3:
2388         case DW_OP_breg4:
2389         case DW_OP_breg5:
2390         case DW_OP_breg6:
2391         case DW_OP_breg7:
2392         case DW_OP_breg8:
2393         case DW_OP_breg9:
2394         case DW_OP_breg10:
2395         case DW_OP_breg11:
2396         case DW_OP_breg12:
2397         case DW_OP_breg13:
2398         case DW_OP_breg14:
2399         case DW_OP_breg15:
2400         case DW_OP_breg16:
2401         case DW_OP_breg17:
2402         case DW_OP_breg18:
2403         case DW_OP_breg19:
2404         case DW_OP_breg20:
2405         case DW_OP_breg21:
2406         case DW_OP_breg22:
2407         case DW_OP_breg23:
2408         case DW_OP_breg24:
2409         case DW_OP_breg25:
2410         case DW_OP_breg26:
2411         case DW_OP_breg27:
2412         case DW_OP_breg28:
2413         case DW_OP_breg29:
2414         case DW_OP_breg30:
2415         case DW_OP_breg31:
2416             {
2417                 reg_num = op - DW_OP_breg0;
2418 
2419                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2420                 {
2421                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2422                     tmp.ResolveValue(exe_ctx, ast_context) += (uint64_t)breg_offset;
2423                     stack.push_back(tmp);
2424                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2425                 }
2426                 else
2427                     return false;
2428             }
2429             break;
2430         //----------------------------------------------------------------------
2431         // OPCODE: DW_OP_bregx
2432         // OPERANDS: 2
2433         //      ULEB128 literal operand that encodes the register.
2434         //      SLEB128 offset from register N
2435         // DESCRIPTION: Value is in memory at the address specified by register
2436         // N plus an offset.
2437         //----------------------------------------------------------------------
2438         case DW_OP_bregx:
2439             {
2440                 reg_num = opcodes.GetULEB128(&offset);
2441 
2442                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2443                 {
2444                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2445                     tmp.ResolveValue(exe_ctx, ast_context) += (uint64_t)breg_offset;
2446                     stack.push_back(tmp);
2447                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2448                 }
2449                 else
2450                     return false;
2451             }
2452             break;
2453 
2454         case DW_OP_fbreg:
2455             if (exe_ctx)
2456             {
2457                 if (frame)
2458                 {
2459                     Scalar value;
2460                     if (frame->GetFrameBaseValue(value, error_ptr))
2461                     {
2462                         int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
2463                         value += fbreg_offset;
2464                         stack.push_back(value);
2465                         stack.back().SetValueType (Value::eValueTypeLoadAddress);
2466                     }
2467                     else
2468                         return false;
2469                 }
2470                 else
2471                 {
2472                     if (error_ptr)
2473                         error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_fbreg opcode.");
2474                     return false;
2475                 }
2476             }
2477             else
2478             {
2479                 if (error_ptr)
2480                     error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_fbreg.\n");
2481                 return false;
2482             }
2483 
2484             break;
2485 
2486         //----------------------------------------------------------------------
2487         // OPCODE: DW_OP_nop
2488         // OPERANDS: none
2489         // DESCRIPTION: A place holder. It has no effect on the location stack
2490         // or any of its values.
2491         //----------------------------------------------------------------------
2492         case DW_OP_nop:
2493             break;
2494 
2495         //----------------------------------------------------------------------
2496         // OPCODE: DW_OP_piece
2497         // OPERANDS: 1
2498         //      ULEB128: byte size of the piece
2499         // DESCRIPTION: The operand describes the size in bytes of the piece of
2500         // the object referenced by the DWARF expression whose result is at the
2501         // top of the stack. If the piece is located in a register, but does not
2502         // occupy the entire register, the placement of the piece within that
2503         // register is defined by the ABI.
2504         //
2505         // Many compilers store a single variable in sets of registers, or store
2506         // a variable partially in memory and partially in registers.
2507         // DW_OP_piece provides a way of describing how large a part of a
2508         // variable a particular DWARF expression refers to.
2509         //----------------------------------------------------------------------
2510         case DW_OP_piece:
2511             if (error_ptr)
2512                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_piece.");
2513             return false;
2514 
2515         //----------------------------------------------------------------------
2516         // OPCODE: DW_OP_push_object_address
2517         // OPERANDS: none
2518         // DESCRIPTION: Pushes the address of the object currently being
2519         // evaluated as part of evaluation of a user presented expression.
2520         // This object may correspond to an independent variable described by
2521         // its own DIE or it may be a component of an array, structure, or class
2522         // whose address has been dynamically determined by an earlier step
2523         // during user expression evaluation.
2524         //----------------------------------------------------------------------
2525         case DW_OP_push_object_address:
2526             if (error_ptr)
2527                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_push_object_address.");
2528             return false;
2529 
2530         //----------------------------------------------------------------------
2531         // OPCODE: DW_OP_call2
2532         // OPERANDS:
2533         //      uint16_t compile unit relative offset of a DIE
2534         // DESCRIPTION: Performs subroutine calls during evaluation
2535         // of a DWARF expression. The operand is the 2-byte unsigned offset
2536         // of a debugging information entry in the current compilation unit.
2537         //
2538         // Operand interpretation is exactly like that for DW_FORM_ref2.
2539         //
2540         // This operation transfers control of DWARF expression evaluation
2541         // to the DW_AT_location attribute of the referenced DIE. If there is
2542         // no such attribute, then there is no effect. Execution of the DWARF
2543         // expression of a DW_AT_location attribute may add to and/or remove from
2544         // values on the stack. Execution returns to the point following the call
2545         // when the end of the attribute is reached. Values on the stack at the
2546         // time of the call may be used as parameters by the called expression
2547         // and values left on the stack by the called expression may be used as
2548         // return values by prior agreement between the calling and called
2549         // expressions.
2550         //----------------------------------------------------------------------
2551         case DW_OP_call2:
2552             if (error_ptr)
2553                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call2.");
2554             return false;
2555         //----------------------------------------------------------------------
2556         // OPCODE: DW_OP_call4
2557         // OPERANDS: 1
2558         //      uint32_t compile unit relative offset of a DIE
2559         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2560         // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset
2561         // of a debugging information entry in  the current compilation unit.
2562         //
2563         // Operand interpretation DW_OP_call4 is exactly like that for
2564         // DW_FORM_ref4.
2565         //
2566         // This operation transfers control of DWARF expression evaluation
2567         // to the DW_AT_location attribute of the referenced DIE. If there is
2568         // no such attribute, then there is no effect. Execution of the DWARF
2569         // expression of a DW_AT_location attribute may add to and/or remove from
2570         // values on the stack. Execution returns to the point following the call
2571         // when the end of the attribute is reached. Values on the stack at the
2572         // time of the call may be used as parameters by the called expression
2573         // and values left on the stack by the called expression may be used as
2574         // return values by prior agreement between the calling and called
2575         // expressions.
2576         //----------------------------------------------------------------------
2577         case DW_OP_call4:
2578             if (error_ptr)
2579                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call4.");
2580             return false;
2581 
2582 #if 0
2583         //----------------------------------------------------------------------
2584         // OPCODE: DW_OP_call_ref
2585         // OPERANDS:
2586         //      uint32_t absolute DIE offset for 32-bit DWARF or a uint64_t
2587         //               absolute DIE offset for 64 bit DWARF.
2588         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2589         // expression. Takes a single operand. In the 32-bit DWARF format, the
2590         // operand is a 4-byte unsigned value; in the 64-bit DWARF format, it
2591         // is an 8-byte unsigned value. The operand is used as the offset of a
2592         // debugging information entry in a .debug_info section which may be
2593         // contained in a shared object for executable other than that
2594         // containing the operator. For references from one shared object or
2595         // executable to another, the relocation must be performed by the
2596         // consumer.
2597         //
2598         // Operand interpretation of DW_OP_call_ref is exactly like that for
2599         // DW_FORM_ref_addr.
2600         //
2601         // This operation transfers control of DWARF expression evaluation
2602         // to the DW_AT_location attribute of the referenced DIE. If there is
2603         // no such attribute, then there is no effect. Execution of the DWARF
2604         // expression of a DW_AT_location attribute may add to and/or remove from
2605         // values on the stack. Execution returns to the point following the call
2606         // when the end of the attribute is reached. Values on the stack at the
2607         // time of the call may be used as parameters by the called expression
2608         // and values left on the stack by the called expression may be used as
2609         // return values by prior agreement between the calling and called
2610         // expressions.
2611         //----------------------------------------------------------------------
2612         case DW_OP_call_ref:
2613             if (error_ptr)
2614                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call_ref.");
2615             return false;
2616 
2617                 //----------------------------------------------------------------------
2618                 // OPCODE: DW_OP_APPLE_array_ref
2619                 // OPERANDS: none
2620                 // DESCRIPTION: Pops a value off the stack and uses it as the array
2621                 // index.  Pops a second value off the stack and uses it as the array
2622                 // itself.  Pushes a value onto the stack representing the element of
2623                 // the array specified by the index.
2624                 //----------------------------------------------------------------------
2625             case DW_OP_APPLE_array_ref:
2626             {
2627                 if (stack.size() < 2)
2628                 {
2629                     if (error_ptr)
2630                         error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_APPLE_array_ref.");
2631                     return false;
2632                 }
2633 
2634                 Value index_val = stack.back();
2635                 stack.pop_back();
2636                 Value array_val = stack.back();
2637                 stack.pop_back();
2638 
2639                 Scalar &index_scalar = index_val.ResolveValue(exe_ctx, ast_context);
2640                 int64_t index = index_scalar.SLongLong(LLONG_MAX);
2641 
2642                 if (index == LLONG_MAX)
2643                 {
2644                     if (error_ptr)
2645                         error_ptr->SetErrorString("Invalid array index.");
2646                     return false;
2647                 }
2648 
2649                 if (array_val.GetContextType() != Value::eContextTypeClangType)
2650                 {
2651                     if (error_ptr)
2652                         error_ptr->SetErrorString("Arrays without Clang types are unhandled at this time.");
2653                     return false;
2654                 }
2655 
2656                 if (array_val.GetValueType() != Value::eValueTypeLoadAddress &&
2657                     array_val.GetValueType() != Value::eValueTypeHostAddress)
2658                 {
2659                     if (error_ptr)
2660                         error_ptr->SetErrorString("Array must be stored in memory.");
2661                     return false;
2662                 }
2663 
2664                 void *array_type = array_val.GetClangType();
2665 
2666                 void *member_type;
2667                 uint64_t size = 0;
2668 
2669                 if ((!ClangASTContext::IsPointerType(array_type, &member_type)) &&
2670                     (!ClangASTContext::IsArrayType(array_type, &member_type, &size)))
2671                 {
2672                     if (error_ptr)
2673                         error_ptr->SetErrorString("Array reference from something that is neither a pointer nor an array.");
2674                     return false;
2675                 }
2676 
2677                 if (size && (index >= size || index < 0))
2678                 {
2679                     if (error_ptr)
2680                         error_ptr->SetErrorStringWithFormat("Out of bounds array access.  %lld is not in [0, %llu]", index, size);
2681                     return false;
2682                 }
2683 
2684                 uint64_t member_bit_size = ClangASTType::GetClangTypeBitWidth(ast_context, member_type);
2685                 uint64_t member_bit_align = ClangASTType::GetTypeBitAlign(ast_context, member_type);
2686                 uint64_t member_bit_incr = ((member_bit_size + member_bit_align - 1) / member_bit_align) * member_bit_align;
2687                 if (member_bit_incr % 8)
2688                 {
2689                     if (error_ptr)
2690                         error_ptr->SetErrorStringWithFormat("Array increment is not byte aligned");
2691                     return false;
2692                 }
2693                 int64_t member_offset = (int64_t)(member_bit_incr / 8) * index;
2694 
2695                 Value member;
2696 
2697                 member.SetContext(Value::eContextTypeClangType, member_type);
2698                 member.SetValueType(array_val.GetValueType());
2699 
2700                 addr_t array_base = (addr_t)array_val.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
2701                 addr_t member_loc = array_base + member_offset;
2702                 member.GetScalar() = (uint64_t)member_loc;
2703 
2704                 stack.push_back(member);
2705             }
2706                 break;
2707 
2708         //----------------------------------------------------------------------
2709         // OPCODE: DW_OP_APPLE_uninit
2710         // OPERANDS: none
2711         // DESCRIPTION: Lets us know that the value is currently not initialized
2712         //----------------------------------------------------------------------
2713         case DW_OP_APPLE_uninit:
2714             //return eResultTypeErrorUninitialized;
2715             break;  // Ignore this as we have seen cases where this value is incorrectly added
2716 
2717         //----------------------------------------------------------------------
2718         // OPCODE: DW_OP_APPLE_assign
2719         // OPERANDS: none
2720         // DESCRIPTION: Pops a value off of the stack and assigns it to the next
2721         // item on the stack which must be something assignable (inferior
2722         // Variable, inferior Type with address, inferior register, or
2723         // expression local variable.
2724         //----------------------------------------------------------------------
2725         case DW_OP_APPLE_assign:
2726             if (stack.size() < 2)
2727             {
2728                 if (error_ptr)
2729                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_APPLE_assign.");
2730                 return false;
2731             }
2732             else
2733             {
2734                 tmp = stack.back();
2735                 stack.pop_back();
2736                 Value::ContextType context_type = stack.back().GetContextType();
2737                 StreamString new_value(Stream::eBinary, 4, lldb::endian::InlHostByteOrder());
2738                 switch (context_type)
2739                 {
2740                 case Value::eContextTypeClangType:
2741                     {
2742                         void *clang_type = stack.back().GetClangType();
2743 
2744                         if (ClangASTContext::IsAggregateType (clang_type))
2745                         {
2746                             Value::ValueType source_value_type = tmp.GetValueType();
2747                             Value::ValueType target_value_type = stack.back().GetValueType();
2748 
2749                             addr_t source_addr = (addr_t)tmp.GetScalar().ULongLong();
2750                             addr_t target_addr = (addr_t)stack.back().GetScalar().ULongLong();
2751 
2752                             size_t byte_size = (ClangASTType::GetClangTypeBitWidth(ast_context, clang_type) + 7) / 8;
2753 
2754                             switch (source_value_type)
2755                             {
2756                             case Value::eValueTypeScalar:
2757                             case Value::eValueTypeFileAddress:
2758                                 break;
2759 
2760                             case Value::eValueTypeLoadAddress:
2761                                 switch (target_value_type)
2762                                 {
2763                                 case Value::eValueTypeLoadAddress:
2764                                     {
2765                                         DataBufferHeap data;
2766                                         data.SetByteSize(byte_size);
2767 
2768                                         Error error;
2769                                         if (process->ReadMemory (source_addr, data.GetBytes(), byte_size, error) != byte_size)
2770                                         {
2771                                             if (error_ptr)
2772                                                 error_ptr->SetErrorStringWithFormat ("Couldn't read a composite type from the target: %s", error.AsCString());
2773                                             return false;
2774                                         }
2775 
2776                                         if (process->WriteMemory (target_addr, data.GetBytes(), byte_size, error) != byte_size)
2777                                         {
2778                                             if (error_ptr)
2779                                                 error_ptr->SetErrorStringWithFormat ("Couldn't write a composite type to the target: %s", error.AsCString());
2780                                             return false;
2781                                         }
2782                                     }
2783                                     break;
2784                                 case Value::eValueTypeHostAddress:
2785                                     if (process->GetByteOrder() != lldb::endian::InlHostByteOrder())
2786                                     {
2787                                         if (error_ptr)
2788                                             error_ptr->SetErrorStringWithFormat ("Copy of composite types between incompatible byte orders is unimplemented");
2789                                         return false;
2790                                     }
2791                                     else
2792                                     {
2793                                         Error error;
2794                                         if (process->ReadMemory (source_addr, (uint8_t*)target_addr, byte_size, error) != byte_size)
2795                                         {
2796                                             if (error_ptr)
2797                                                 error_ptr->SetErrorStringWithFormat ("Couldn't read a composite type from the target: %s", error.AsCString());
2798                                             return false;
2799                                         }
2800                                     }
2801                                     break;
2802                                 default:
2803                                     return false;
2804                                 }
2805                                 break;
2806                             case Value::eValueTypeHostAddress:
2807                                 switch (target_value_type)
2808                                 {
2809                                 case Value::eValueTypeLoadAddress:
2810                                     if (process->GetByteOrder() != lldb::endian::InlHostByteOrder())
2811                                     {
2812                                         if (error_ptr)
2813                                             error_ptr->SetErrorStringWithFormat ("Copy of composite types between incompatible byte orders is unimplemented");
2814                                         return false;
2815                                     }
2816                                     else
2817                                     {
2818                                         Error error;
2819                                         if (process->WriteMemory (target_addr, (uint8_t*)source_addr, byte_size, error) != byte_size)
2820                                         {
2821                                             if (error_ptr)
2822                                                 error_ptr->SetErrorStringWithFormat ("Couldn't write a composite type to the target: %s", error.AsCString());
2823                                             return false;
2824                                         }
2825                                     }
2826                                 case Value::eValueTypeHostAddress:
2827                                     memcpy ((uint8_t*)target_addr, (uint8_t*)source_addr, byte_size);
2828                                     break;
2829                                 default:
2830                                     return false;
2831                                 }
2832                             }
2833                         }
2834                         else
2835                         {
2836                             if (!ClangASTType::SetValueFromScalar (ast_context,
2837                                                                   clang_type,
2838                                                                   tmp.ResolveValue(exe_ctx, ast_context),
2839                                                                   new_value))
2840                             {
2841                                 if (error_ptr)
2842                                     error_ptr->SetErrorStringWithFormat ("Couldn't extract a value from an integral type.\n");
2843                                 return false;
2844                             }
2845 
2846                             Value::ValueType value_type = stack.back().GetValueType();
2847 
2848                             switch (value_type)
2849                             {
2850                             case Value::eValueTypeLoadAddress:
2851                             case Value::eValueTypeHostAddress:
2852                                 {
2853                                     AddressType address_type = (value_type == Value::eValueTypeLoadAddress ? eAddressTypeLoad : eAddressTypeHost);
2854                                     lldb::addr_t addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
2855                                     if (!ClangASTType::WriteToMemory (ast_context,
2856                                                                           clang_type,
2857                                                                           exe_ctx,
2858                                                                           addr,
2859                                                                           address_type,
2860                                                                           new_value))
2861                                     {
2862                                         if (error_ptr)
2863                                             error_ptr->SetErrorStringWithFormat ("Failed to write value to memory at 0x%llx.\n", addr);
2864                                         return false;
2865                                     }
2866                                 }
2867                                 break;
2868 
2869                             default:
2870                                 break;
2871                             }
2872                         }
2873                     }
2874                     break;
2875 
2876                 default:
2877                     if (error_ptr)
2878                         error_ptr->SetErrorString ("Assign failed.");
2879                     return false;
2880                 }
2881             }
2882             break;
2883 
2884         //----------------------------------------------------------------------
2885         // OPCODE: DW_OP_APPLE_address_of
2886         // OPERANDS: none
2887         // DESCRIPTION: Pops a value off of the stack and pushed its address.
2888         // The top item on the stack must be a variable, or already be a memory
2889         // location.
2890         //----------------------------------------------------------------------
2891         case DW_OP_APPLE_address_of:
2892             if (stack.empty())
2893             {
2894                 if (error_ptr)
2895                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_APPLE_address_of.");
2896                 return false;
2897             }
2898             else
2899             {
2900                 Value::ValueType value_type = stack.back().GetValueType();
2901                 switch (value_type)
2902                 {
2903                 default:
2904                 case Value::eValueTypeScalar:      // raw scalar value
2905                     if (error_ptr)
2906                         error_ptr->SetErrorString("Top stack item isn't a memory based object.");
2907                     return false;
2908 
2909                 case Value::eValueTypeLoadAddress: // load address value
2910                 case Value::eValueTypeFileAddress: // file address value
2911                 case Value::eValueTypeHostAddress: // host address value (for memory in the process that is using liblldb)
2912                     // Taking the address of an object reduces it to the address
2913                     // of the value and removes any extra context it had.
2914                     //stack.back().SetValueType(Value::eValueTypeScalar);
2915                     stack.back().ClearContext();
2916                     break;
2917                 }
2918             }
2919             break;
2920 
2921         //----------------------------------------------------------------------
2922         // OPCODE: DW_OP_APPLE_value_of
2923         // OPERANDS: none
2924         // DESCRIPTION: Pops a value off of the stack and pushed its value.
2925         // The top item on the stack must be a variable, expression variable.
2926         //----------------------------------------------------------------------
2927         case DW_OP_APPLE_value_of:
2928             if (stack.empty())
2929             {
2930                 if (error_ptr)
2931                     error_ptr->SetErrorString("Expression stack needs at least 1 items for DW_OP_APPLE_value_of.");
2932                 return false;
2933             }
2934             else if (!stack.back().ValueOf(exe_ctx, ast_context))
2935             {
2936                 if (error_ptr)
2937                     error_ptr->SetErrorString ("Top stack item isn't a valid candidate for DW_OP_APPLE_value_of.");
2938                 return false;
2939             }
2940             break;
2941 
2942         //----------------------------------------------------------------------
2943         // OPCODE: DW_OP_APPLE_deref_type
2944         // OPERANDS: none
2945         // DESCRIPTION: gets the value pointed to by the top stack item
2946         //----------------------------------------------------------------------
2947         case DW_OP_APPLE_deref_type:
2948             {
2949                 if (stack.empty())
2950                 {
2951                     if (error_ptr)
2952                         error_ptr->SetErrorString("Expression stack needs at least 1 items for DW_OP_APPLE_deref_type.");
2953                     return false;
2954                 }
2955 
2956                 tmp = stack.back();
2957                 stack.pop_back();
2958 
2959                 if (tmp.GetContextType() != Value::eContextTypeClangType)
2960                 {
2961                     if (error_ptr)
2962                         error_ptr->SetErrorString("Item at top of expression stack must have a Clang type");
2963                     return false;
2964                 }
2965 
2966                 void *ptr_type = tmp.GetClangType();
2967                 void *target_type;
2968 
2969                 if (!ClangASTContext::IsPointerType(ptr_type, &target_type))
2970                 {
2971                     if (error_ptr)
2972                         error_ptr->SetErrorString("Dereferencing a non-pointer type");
2973                     return false;
2974                 }
2975 
2976                 // TODO do we want all pointers to be dereferenced as load addresses?
2977                 Value::ValueType value_type = tmp.GetValueType();
2978 
2979                 tmp.ResolveValue(exe_ctx, ast_context);
2980 
2981                 tmp.SetValueType(value_type);
2982                 tmp.SetContext(Value::eContextTypeClangType, target_type);
2983 
2984                 stack.push_back(tmp);
2985             }
2986             break;
2987 
2988         //----------------------------------------------------------------------
2989         // OPCODE: DW_OP_APPLE_expr_local
2990         // OPERANDS: ULEB128
2991         // DESCRIPTION: pushes the expression local variable index onto the
2992         // stack and set the appropriate context so we know the stack item is
2993         // an expression local variable index.
2994         //----------------------------------------------------------------------
2995         case DW_OP_APPLE_expr_local:
2996             {
2997                 /*
2998                 uint32_t idx = opcodes.GetULEB128(&offset);
2999                 if (expr_locals == NULL)
3000                 {
3001                     if (error_ptr)
3002                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_expr_local(%u) opcode encountered with no local variable list.\n", idx);
3003                     return false;
3004                 }
3005                 Value *expr_local_variable = expr_locals->GetVariableAtIndex(idx);
3006                 if (expr_local_variable == NULL)
3007                 {
3008                     if (error_ptr)
3009                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_expr_local(%u) with invalid index %u.\n", idx, idx);
3010                     return false;
3011                 }
3012                  // The proxy code has been removed. If it is ever re-added, please
3013                  // use shared pointers or return by value to avoid possible memory
3014                  // leak (there is no leak here, but in general, no returning pointers
3015                  // that must be manually freed please.
3016                 Value *proxy = expr_local_variable->CreateProxy();
3017                 stack.push_back(*proxy);
3018                 delete proxy;
3019                 //stack.back().SetContext (Value::eContextTypeClangType, expr_local_variable->GetClangType());
3020                 */
3021             }
3022             break;
3023 
3024         //----------------------------------------------------------------------
3025         // OPCODE: DW_OP_APPLE_extern
3026         // OPERANDS: ULEB128
3027         // DESCRIPTION: pushes a proxy for the extern object index onto the
3028         // stack.
3029         //----------------------------------------------------------------------
3030         case DW_OP_APPLE_extern:
3031             {
3032                 /*
3033                 uint32_t idx = opcodes.GetULEB128(&offset);
3034                 if (!decl_map)
3035                 {
3036                     if (error_ptr)
3037                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_extern(%u) opcode encountered with no decl map.\n", idx);
3038                     return false;
3039                 }
3040                 Value *extern_var = decl_map->GetValueForIndex(idx);
3041                 if (!extern_var)
3042                 {
3043                     if (error_ptr)
3044                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_extern(%u) with invalid index %u.\n", idx, idx);
3045                     return false;
3046                 }
3047                 // The proxy code has been removed. If it is ever re-added, please
3048                 // use shared pointers or return by value to avoid possible memory
3049                 // leak (there is no leak here, but in general, no returning pointers
3050                 // that must be manually freed please.
3051                 Value *proxy = extern_var->CreateProxy();
3052                 stack.push_back(*proxy);
3053                 delete proxy;
3054                 */
3055             }
3056             break;
3057 
3058         case DW_OP_APPLE_scalar_cast:
3059             if (stack.empty())
3060             {
3061                 if (error_ptr)
3062                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_APPLE_scalar_cast.");
3063                 return false;
3064             }
3065             else
3066             {
3067                 // Simple scalar cast
3068                 if (!stack.back().ResolveValue(exe_ctx, ast_context).Cast((Scalar::Type)opcodes.GetU8(&offset)))
3069                 {
3070                     if (error_ptr)
3071                         error_ptr->SetErrorString("Cast failed.");
3072                     return false;
3073                 }
3074             }
3075             break;
3076 
3077 
3078         case DW_OP_APPLE_clang_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_clang_cast.");
3083                 return false;
3084             }
3085             else
3086             {
3087                 void *clang_type = (void *)opcodes.GetMaxU64(&offset, sizeof(void*));
3088                 stack.back().SetContext (Value::eContextTypeClangType, clang_type);
3089             }
3090             break;
3091         //----------------------------------------------------------------------
3092         // OPCODE: DW_OP_APPLE_constf
3093         // OPERANDS: 1 byte float length, followed by that many bytes containing
3094         // the constant float data.
3095         // DESCRIPTION: Push a float value onto the expression stack.
3096         //----------------------------------------------------------------------
3097         case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
3098             {
3099                 uint8_t float_length = opcodes.GetU8(&offset);
3100                 if (sizeof(float) == float_length)
3101                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetFloat (&offset);
3102                 else if (sizeof(double) == float_length)
3103                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetDouble (&offset);
3104                 else if (sizeof(long double) == float_length)
3105                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetLongDouble (&offset);
3106                 else
3107                 {
3108                     StreamString new_value;
3109                     opcodes.Dump(&new_value, offset, eFormatBytes, 1, float_length, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
3110 
3111                      if (error_ptr)
3112                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_constf(<%u> %s) unsupported float size.\n", float_length, new_value.GetData());
3113                     return false;
3114                }
3115                tmp.SetValueType(Value::eValueTypeScalar);
3116                tmp.ClearContext();
3117                stack.push_back(tmp);
3118             }
3119             break;
3120         //----------------------------------------------------------------------
3121         // OPCODE: DW_OP_APPLE_clear
3122         // OPERANDS: none
3123         // DESCRIPTION: Clears the expression stack.
3124         //----------------------------------------------------------------------
3125         case DW_OP_APPLE_clear:
3126             stack.clear();
3127             break;
3128 
3129         //----------------------------------------------------------------------
3130         // OPCODE: DW_OP_APPLE_error
3131         // OPERANDS: none
3132         // DESCRIPTION: Pops a value off of the stack and pushed its value.
3133         // The top item on the stack must be a variable, expression variable.
3134         //----------------------------------------------------------------------
3135         case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
3136             if (error_ptr)
3137                 error_ptr->SetErrorString ("Generic error.");
3138             return false;
3139 #endif // #if 0
3140 
3141         }
3142     }
3143 
3144     if (stack.empty())
3145     {
3146         if (error_ptr)
3147             error_ptr->SetErrorString ("Stack empty after evaluation.");
3148         return false;
3149     }
3150     else if (log && log->GetVerbose())
3151     {
3152         size_t count = stack.size();
3153         log->Printf("Stack after operation has %lu values:", count);
3154         for (size_t i=0; i<count; ++i)
3155         {
3156             StreamString new_value;
3157             new_value.Printf("[%zu]", i);
3158             stack[i].Dump(&new_value);
3159             log->Printf("  %s", new_value.GetData());
3160         }
3161     }
3162 
3163     result = stack.back();
3164     return true;    // Return true on success
3165 }
3166 
3167