1 //===-- DWARFExpression.cpp -------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Expression/DWARFExpression.h"
11 
12 #include <vector>
13 
14 #include "lldb/Core/DataEncoder.h"
15 #include "lldb/Core/dwarf.h"
16 #include "lldb/Core/Log.h"
17 #include "lldb/Core/RegisterValue.h"
18 #include "lldb/Core/StreamString.h"
19 #include "lldb/Core/Scalar.h"
20 #include "lldb/Core/Value.h"
21 #include "lldb/Core/VMRange.h"
22 
23 #include "lldb/Expression/ClangExpressionDeclMap.h"
24 #include "lldb/Expression/ClangExpressionVariable.h"
25 
26 #include "lldb/Host/Endian.h"
27 #include "lldb/Host/Host.h"
28 
29 #include "lldb/lldb-private-log.h"
30 
31 #include "lldb/Symbol/ClangASTType.h"
32 #include "lldb/Symbol/ClangASTContext.h"
33 #include "lldb/Symbol/Type.h"
34 
35 #include "lldb/Target/ABI.h"
36 #include "lldb/Target/ExecutionContext.h"
37 #include "lldb/Target/Process.h"
38 #include "lldb/Target/RegisterContext.h"
39 #include "lldb/Target/StackFrame.h"
40 
41 using namespace lldb;
42 using namespace lldb_private;
43 
44 const char *
45 DW_OP_value_to_name (uint32_t val)
46 {
47   static char invalid[100];
48   switch (val) {
49     case 0x03: return "DW_OP_addr";
50     case 0x06: return "DW_OP_deref";
51     case 0x08: return "DW_OP_const1u";
52     case 0x09: return "DW_OP_const1s";
53     case 0x0a: return "DW_OP_const2u";
54     case 0x0b: return "DW_OP_const2s";
55     case 0x0c: return "DW_OP_const4u";
56     case 0x0d: return "DW_OP_const4s";
57     case 0x0e: return "DW_OP_const8u";
58     case 0x0f: return "DW_OP_const8s";
59     case 0x10: return "DW_OP_constu";
60     case 0x11: return "DW_OP_consts";
61     case 0x12: return "DW_OP_dup";
62     case 0x13: return "DW_OP_drop";
63     case 0x14: return "DW_OP_over";
64     case 0x15: return "DW_OP_pick";
65     case 0x16: return "DW_OP_swap";
66     case 0x17: return "DW_OP_rot";
67     case 0x18: return "DW_OP_xderef";
68     case 0x19: return "DW_OP_abs";
69     case 0x1a: return "DW_OP_and";
70     case 0x1b: return "DW_OP_div";
71     case 0x1c: return "DW_OP_minus";
72     case 0x1d: return "DW_OP_mod";
73     case 0x1e: return "DW_OP_mul";
74     case 0x1f: return "DW_OP_neg";
75     case 0x20: return "DW_OP_not";
76     case 0x21: return "DW_OP_or";
77     case 0x22: return "DW_OP_plus";
78     case 0x23: return "DW_OP_plus_uconst";
79     case 0x24: return "DW_OP_shl";
80     case 0x25: return "DW_OP_shr";
81     case 0x26: return "DW_OP_shra";
82     case 0x27: return "DW_OP_xor";
83     case 0x2f: return "DW_OP_skip";
84     case 0x28: return "DW_OP_bra";
85     case 0x29: return "DW_OP_eq";
86     case 0x2a: return "DW_OP_ge";
87     case 0x2b: return "DW_OP_gt";
88     case 0x2c: return "DW_OP_le";
89     case 0x2d: return "DW_OP_lt";
90     case 0x2e: return "DW_OP_ne";
91     case 0x30: return "DW_OP_lit0";
92     case 0x31: return "DW_OP_lit1";
93     case 0x32: return "DW_OP_lit2";
94     case 0x33: return "DW_OP_lit3";
95     case 0x34: return "DW_OP_lit4";
96     case 0x35: return "DW_OP_lit5";
97     case 0x36: return "DW_OP_lit6";
98     case 0x37: return "DW_OP_lit7";
99     case 0x38: return "DW_OP_lit8";
100     case 0x39: return "DW_OP_lit9";
101     case 0x3a: return "DW_OP_lit10";
102     case 0x3b: return "DW_OP_lit11";
103     case 0x3c: return "DW_OP_lit12";
104     case 0x3d: return "DW_OP_lit13";
105     case 0x3e: return "DW_OP_lit14";
106     case 0x3f: return "DW_OP_lit15";
107     case 0x40: return "DW_OP_lit16";
108     case 0x41: return "DW_OP_lit17";
109     case 0x42: return "DW_OP_lit18";
110     case 0x43: return "DW_OP_lit19";
111     case 0x44: return "DW_OP_lit20";
112     case 0x45: return "DW_OP_lit21";
113     case 0x46: return "DW_OP_lit22";
114     case 0x47: return "DW_OP_lit23";
115     case 0x48: return "DW_OP_lit24";
116     case 0x49: return "DW_OP_lit25";
117     case 0x4a: return "DW_OP_lit26";
118     case 0x4b: return "DW_OP_lit27";
119     case 0x4c: return "DW_OP_lit28";
120     case 0x4d: return "DW_OP_lit29";
121     case 0x4e: return "DW_OP_lit30";
122     case 0x4f: return "DW_OP_lit31";
123     case 0x50: return "DW_OP_reg0";
124     case 0x51: return "DW_OP_reg1";
125     case 0x52: return "DW_OP_reg2";
126     case 0x53: return "DW_OP_reg3";
127     case 0x54: return "DW_OP_reg4";
128     case 0x55: return "DW_OP_reg5";
129     case 0x56: return "DW_OP_reg6";
130     case 0x57: return "DW_OP_reg7";
131     case 0x58: return "DW_OP_reg8";
132     case 0x59: return "DW_OP_reg9";
133     case 0x5a: return "DW_OP_reg10";
134     case 0x5b: return "DW_OP_reg11";
135     case 0x5c: return "DW_OP_reg12";
136     case 0x5d: return "DW_OP_reg13";
137     case 0x5e: return "DW_OP_reg14";
138     case 0x5f: return "DW_OP_reg15";
139     case 0x60: return "DW_OP_reg16";
140     case 0x61: return "DW_OP_reg17";
141     case 0x62: return "DW_OP_reg18";
142     case 0x63: return "DW_OP_reg19";
143     case 0x64: return "DW_OP_reg20";
144     case 0x65: return "DW_OP_reg21";
145     case 0x66: return "DW_OP_reg22";
146     case 0x67: return "DW_OP_reg23";
147     case 0x68: return "DW_OP_reg24";
148     case 0x69: return "DW_OP_reg25";
149     case 0x6a: return "DW_OP_reg26";
150     case 0x6b: return "DW_OP_reg27";
151     case 0x6c: return "DW_OP_reg28";
152     case 0x6d: return "DW_OP_reg29";
153     case 0x6e: return "DW_OP_reg30";
154     case 0x6f: return "DW_OP_reg31";
155     case 0x70: return "DW_OP_breg0";
156     case 0x71: return "DW_OP_breg1";
157     case 0x72: return "DW_OP_breg2";
158     case 0x73: return "DW_OP_breg3";
159     case 0x74: return "DW_OP_breg4";
160     case 0x75: return "DW_OP_breg5";
161     case 0x76: return "DW_OP_breg6";
162     case 0x77: return "DW_OP_breg7";
163     case 0x78: return "DW_OP_breg8";
164     case 0x79: return "DW_OP_breg9";
165     case 0x7a: return "DW_OP_breg10";
166     case 0x7b: return "DW_OP_breg11";
167     case 0x7c: return "DW_OP_breg12";
168     case 0x7d: return "DW_OP_breg13";
169     case 0x7e: return "DW_OP_breg14";
170     case 0x7f: return "DW_OP_breg15";
171     case 0x80: return "DW_OP_breg16";
172     case 0x81: return "DW_OP_breg17";
173     case 0x82: return "DW_OP_breg18";
174     case 0x83: return "DW_OP_breg19";
175     case 0x84: return "DW_OP_breg20";
176     case 0x85: return "DW_OP_breg21";
177     case 0x86: return "DW_OP_breg22";
178     case 0x87: return "DW_OP_breg23";
179     case 0x88: return "DW_OP_breg24";
180     case 0x89: return "DW_OP_breg25";
181     case 0x8a: return "DW_OP_breg26";
182     case 0x8b: return "DW_OP_breg27";
183     case 0x8c: return "DW_OP_breg28";
184     case 0x8d: return "DW_OP_breg29";
185     case 0x8e: return "DW_OP_breg30";
186     case 0x8f: return "DW_OP_breg31";
187     case 0x90: return "DW_OP_regx";
188     case 0x91: return "DW_OP_fbreg";
189     case 0x92: return "DW_OP_bregx";
190     case 0x93: return "DW_OP_piece";
191     case 0x94: return "DW_OP_deref_size";
192     case 0x95: return "DW_OP_xderef_size";
193     case 0x96: return "DW_OP_nop";
194     case 0x97: return "DW_OP_push_object_address";
195     case 0x98: return "DW_OP_call2";
196     case 0x99: return "DW_OP_call4";
197     case 0x9a: return "DW_OP_call_ref";
198 //    case DW_OP_APPLE_array_ref: return "DW_OP_APPLE_array_ref";
199 //    case DW_OP_APPLE_extern: return "DW_OP_APPLE_extern";
200     case DW_OP_APPLE_uninit: return "DW_OP_APPLE_uninit";
201 //    case DW_OP_APPLE_assign: return "DW_OP_APPLE_assign";
202 //    case DW_OP_APPLE_address_of: return "DW_OP_APPLE_address_of";
203 //    case DW_OP_APPLE_value_of: return "DW_OP_APPLE_value_of";
204 //    case DW_OP_APPLE_deref_type: return "DW_OP_APPLE_deref_type";
205 //    case DW_OP_APPLE_expr_local: return "DW_OP_APPLE_expr_local";
206 //    case DW_OP_APPLE_constf: return "DW_OP_APPLE_constf";
207 //    case DW_OP_APPLE_scalar_cast: return "DW_OP_APPLE_scalar_cast";
208 //    case DW_OP_APPLE_clang_cast: return "DW_OP_APPLE_clang_cast";
209 //    case DW_OP_APPLE_clear: return "DW_OP_APPLE_clear";
210 //    case DW_OP_APPLE_error: return "DW_OP_APPLE_error";
211     default:
212        snprintf (invalid, sizeof(invalid), "Unknown DW_OP constant: 0x%x", val);
213        return invalid;
214   }
215 }
216 
217 
218 //----------------------------------------------------------------------
219 // DWARFExpression constructor
220 //----------------------------------------------------------------------
221 DWARFExpression::DWARFExpression() :
222     m_data(),
223     m_reg_kind (eRegisterKindDWARF),
224     m_loclist_slide (LLDB_INVALID_ADDRESS)
225 {
226 }
227 
228 DWARFExpression::DWARFExpression(const DWARFExpression& rhs) :
229     m_data(rhs.m_data),
230     m_reg_kind (rhs.m_reg_kind),
231     m_loclist_slide(rhs.m_loclist_slide)
232 {
233 }
234 
235 
236 DWARFExpression::DWARFExpression(const DataExtractor& data, uint32_t data_offset, uint32_t data_length) :
237     m_data(data, data_offset, data_length),
238     m_reg_kind (eRegisterKindDWARF),
239     m_loclist_slide(LLDB_INVALID_ADDRESS)
240 {
241 }
242 
243 //----------------------------------------------------------------------
244 // Destructor
245 //----------------------------------------------------------------------
246 DWARFExpression::~DWARFExpression()
247 {
248 }
249 
250 
251 bool
252 DWARFExpression::IsValid() const
253 {
254     return m_data.GetByteSize() > 0;
255 }
256 
257 void
258 DWARFExpression::SetOpcodeData (const DataExtractor& data)
259 {
260     m_data = data;
261 }
262 
263 void
264 DWARFExpression::CopyOpcodeData (const DataExtractor& data, uint32_t data_offset, uint32_t data_length)
265 {
266     const uint8_t *bytes = data.PeekData(data_offset, data_length);
267     if (bytes)
268     {
269         m_data.SetData(DataBufferSP(new DataBufferHeap(bytes, data_length)));
270         m_data.SetByteOrder(data.GetByteOrder());
271         m_data.SetAddressByteSize(data.GetAddressByteSize());
272     }
273 }
274 
275 void
276 DWARFExpression::SetOpcodeData (const DataExtractor& data, uint32_t data_offset, uint32_t data_length)
277 {
278     m_data.SetData(data, data_offset, data_length);
279 }
280 
281 void
282 DWARFExpression::DumpLocation (Stream *s, uint32_t offset, uint32_t length, lldb::DescriptionLevel level, ABI *abi) const
283 {
284     if (!m_data.ValidOffsetForDataOfSize(offset, length))
285         return;
286     const uint32_t start_offset = offset;
287     const uint32_t end_offset = offset + length;
288     while (m_data.ValidOffset(offset) && offset < end_offset)
289     {
290         const uint32_t op_offset = offset;
291         const uint8_t op = m_data.GetU8(&offset);
292 
293         switch (level)
294         {
295         default:
296             break;
297 
298         case lldb::eDescriptionLevelBrief:
299             if (offset > start_offset)
300                 s->PutChar(' ');
301             break;
302 
303         case lldb::eDescriptionLevelFull:
304         case lldb::eDescriptionLevelVerbose:
305             if (offset > start_offset)
306                 s->EOL();
307             s->Indent();
308             if (level == lldb::eDescriptionLevelFull)
309                 break;
310             // Fall through for verbose and print offset and DW_OP prefix..
311             s->Printf("0x%8.8x: %s", op_offset, op >= DW_OP_APPLE_uninit ? "DW_OP_APPLE_" : "DW_OP_");
312             break;
313         }
314 
315         switch (op)
316         {
317         case DW_OP_addr:    *s << "DW_OP_addr(" << m_data.GetAddress(&offset) << ") "; break;         // 0x03 1 address
318         case DW_OP_deref:   *s << "DW_OP_deref"; break;                                               // 0x06
319         case DW_OP_const1u: s->Printf("DW_OP_const1u(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x08 1 1-byte constant
320         case DW_OP_const1s: s->Printf("DW_OP_const1s(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x09 1 1-byte constant
321         case DW_OP_const2u: s->Printf("DW_OP_const2u(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0a 1 2-byte constant
322         case DW_OP_const2s: s->Printf("DW_OP_const2s(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0b 1 2-byte constant
323         case DW_OP_const4u: s->Printf("DW_OP_const4u(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0c 1 4-byte constant
324         case DW_OP_const4s: s->Printf("DW_OP_const4s(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0d 1 4-byte constant
325         case DW_OP_const8u: s->Printf("DW_OP_const8u(0x%16.16llx) ", m_data.GetU64(&offset)); break;  // 0x0e 1 8-byte constant
326         case DW_OP_const8s: s->Printf("DW_OP_const8s(0x%16.16llx) ", m_data.GetU64(&offset)); break;  // 0x0f 1 8-byte constant
327         case DW_OP_constu:  s->Printf("DW_OP_constu(0x%llx) ", m_data.GetULEB128(&offset)); break;    // 0x10 1 ULEB128 constant
328         case DW_OP_consts:  s->Printf("DW_OP_consts(0x%lld) ", m_data.GetSLEB128(&offset)); break;    // 0x11 1 SLEB128 constant
329         case DW_OP_dup:     s->PutCString("DW_OP_dup"); break;                                        // 0x12
330         case DW_OP_drop:    s->PutCString("DW_OP_drop"); break;                                       // 0x13
331         case DW_OP_over:    s->PutCString("DW_OP_over"); break;                                       // 0x14
332         case DW_OP_pick:    s->Printf("DW_OP_pick(0x%2.2x) ", m_data.GetU8(&offset)); break;          // 0x15 1 1-byte stack index
333         case DW_OP_swap:    s->PutCString("DW_OP_swap"); break;                                       // 0x16
334         case DW_OP_rot:     s->PutCString("DW_OP_rot"); break;                                        // 0x17
335         case DW_OP_xderef:  s->PutCString("DW_OP_xderef"); break;                                     // 0x18
336         case DW_OP_abs:     s->PutCString("DW_OP_abs"); break;                                        // 0x19
337         case DW_OP_and:     s->PutCString("DW_OP_and"); break;                                        // 0x1a
338         case DW_OP_div:     s->PutCString("DW_OP_div"); break;                                        // 0x1b
339         case DW_OP_minus:   s->PutCString("DW_OP_minus"); break;                                      // 0x1c
340         case DW_OP_mod:     s->PutCString("DW_OP_mod"); break;                                        // 0x1d
341         case DW_OP_mul:     s->PutCString("DW_OP_mul"); break;                                        // 0x1e
342         case DW_OP_neg:     s->PutCString("DW_OP_neg"); break;                                        // 0x1f
343         case DW_OP_not:     s->PutCString("DW_OP_not"); break;                                        // 0x20
344         case DW_OP_or:      s->PutCString("DW_OP_or"); break;                                         // 0x21
345         case DW_OP_plus:    s->PutCString("DW_OP_plus"); break;                                       // 0x22
346         case DW_OP_plus_uconst:                                                                 // 0x23 1 ULEB128 addend
347             s->Printf("DW_OP_plus_uconst(0x%llx) ", m_data.GetULEB128(&offset));
348             break;
349 
350         case DW_OP_shl:     s->PutCString("DW_OP_shl"); break;                                        // 0x24
351         case DW_OP_shr:     s->PutCString("DW_OP_shr"); break;                                        // 0x25
352         case DW_OP_shra:    s->PutCString("DW_OP_shra"); break;                                       // 0x26
353         case DW_OP_xor:     s->PutCString("DW_OP_xor"); break;                                        // 0x27
354         case DW_OP_skip:    s->Printf("DW_OP_skip(0x%4.4x)", m_data.GetU16(&offset)); break;          // 0x2f 1 signed 2-byte constant
355         case DW_OP_bra:     s->Printf("DW_OP_bra(0x%4.4x)", m_data.GetU16(&offset)); break;           // 0x28 1 signed 2-byte constant
356         case DW_OP_eq:      s->PutCString("DW_OP_eq"); break;                                         // 0x29
357         case DW_OP_ge:      s->PutCString("DW_OP_ge"); break;                                         // 0x2a
358         case DW_OP_gt:      s->PutCString("DW_OP_gt"); break;                                         // 0x2b
359         case DW_OP_le:      s->PutCString("DW_OP_le"); break;                                         // 0x2c
360         case DW_OP_lt:      s->PutCString("DW_OP_lt"); break;                                         // 0x2d
361         case DW_OP_ne:      s->PutCString("DW_OP_ne"); break;                                         // 0x2e
362 
363         case DW_OP_lit0:    // 0x30
364         case DW_OP_lit1:    // 0x31
365         case DW_OP_lit2:    // 0x32
366         case DW_OP_lit3:    // 0x33
367         case DW_OP_lit4:    // 0x34
368         case DW_OP_lit5:    // 0x35
369         case DW_OP_lit6:    // 0x36
370         case DW_OP_lit7:    // 0x37
371         case DW_OP_lit8:    // 0x38
372         case DW_OP_lit9:    // 0x39
373         case DW_OP_lit10:   // 0x3A
374         case DW_OP_lit11:   // 0x3B
375         case DW_OP_lit12:   // 0x3C
376         case DW_OP_lit13:   // 0x3D
377         case DW_OP_lit14:   // 0x3E
378         case DW_OP_lit15:   // 0x3F
379         case DW_OP_lit16:   // 0x40
380         case DW_OP_lit17:   // 0x41
381         case DW_OP_lit18:   // 0x42
382         case DW_OP_lit19:   // 0x43
383         case DW_OP_lit20:   // 0x44
384         case DW_OP_lit21:   // 0x45
385         case DW_OP_lit22:   // 0x46
386         case DW_OP_lit23:   // 0x47
387         case DW_OP_lit24:   // 0x48
388         case DW_OP_lit25:   // 0x49
389         case DW_OP_lit26:   // 0x4A
390         case DW_OP_lit27:   // 0x4B
391         case DW_OP_lit28:   // 0x4C
392         case DW_OP_lit29:   // 0x4D
393         case DW_OP_lit30:   // 0x4E
394         case DW_OP_lit31:   s->Printf("DW_OP_lit%i", op - DW_OP_lit0); break; // 0x4f
395 
396         case DW_OP_reg0:    // 0x50
397         case DW_OP_reg1:    // 0x51
398         case DW_OP_reg2:    // 0x52
399         case DW_OP_reg3:    // 0x53
400         case DW_OP_reg4:    // 0x54
401         case DW_OP_reg5:    // 0x55
402         case DW_OP_reg6:    // 0x56
403         case DW_OP_reg7:    // 0x57
404         case DW_OP_reg8:    // 0x58
405         case DW_OP_reg9:    // 0x59
406         case DW_OP_reg10:   // 0x5A
407         case DW_OP_reg11:   // 0x5B
408         case DW_OP_reg12:   // 0x5C
409         case DW_OP_reg13:   // 0x5D
410         case DW_OP_reg14:   // 0x5E
411         case DW_OP_reg15:   // 0x5F
412         case DW_OP_reg16:   // 0x60
413         case DW_OP_reg17:   // 0x61
414         case DW_OP_reg18:   // 0x62
415         case DW_OP_reg19:   // 0x63
416         case DW_OP_reg20:   // 0x64
417         case DW_OP_reg21:   // 0x65
418         case DW_OP_reg22:   // 0x66
419         case DW_OP_reg23:   // 0x67
420         case DW_OP_reg24:   // 0x68
421         case DW_OP_reg25:   // 0x69
422         case DW_OP_reg26:   // 0x6A
423         case DW_OP_reg27:   // 0x6B
424         case DW_OP_reg28:   // 0x6C
425         case DW_OP_reg29:   // 0x6D
426         case DW_OP_reg30:   // 0x6E
427         case DW_OP_reg31:   // 0x6F
428             {
429                 uint32_t reg_num = op - DW_OP_reg0;
430                 if (abi)
431                 {
432                     RegisterInfo reg_info;
433                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
434                     {
435                         if (reg_info.name)
436                         {
437                             s->PutCString (reg_info.name);
438                             break;
439                         }
440                         else if (reg_info.alt_name)
441                         {
442                             s->PutCString (reg_info.alt_name);
443                             break;
444                         }
445                     }
446                 }
447                 s->Printf("DW_OP_reg%u", reg_num); break;
448             }
449             break;
450 
451         case DW_OP_breg0:
452         case DW_OP_breg1:
453         case DW_OP_breg2:
454         case DW_OP_breg3:
455         case DW_OP_breg4:
456         case DW_OP_breg5:
457         case DW_OP_breg6:
458         case DW_OP_breg7:
459         case DW_OP_breg8:
460         case DW_OP_breg9:
461         case DW_OP_breg10:
462         case DW_OP_breg11:
463         case DW_OP_breg12:
464         case DW_OP_breg13:
465         case DW_OP_breg14:
466         case DW_OP_breg15:
467         case DW_OP_breg16:
468         case DW_OP_breg17:
469         case DW_OP_breg18:
470         case DW_OP_breg19:
471         case DW_OP_breg20:
472         case DW_OP_breg21:
473         case DW_OP_breg22:
474         case DW_OP_breg23:
475         case DW_OP_breg24:
476         case DW_OP_breg25:
477         case DW_OP_breg26:
478         case DW_OP_breg27:
479         case DW_OP_breg28:
480         case DW_OP_breg29:
481         case DW_OP_breg30:
482         case DW_OP_breg31:
483             {
484                 uint32_t reg_num = op - DW_OP_breg0;
485                 int64_t reg_offset = m_data.GetSLEB128(&offset);
486                 if (abi)
487                 {
488                     RegisterInfo reg_info;
489                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
490                     {
491                         if (reg_info.name)
492                         {
493                             s->Printf("[%s%+lli]", reg_info.name, reg_offset);
494                             break;
495                         }
496                         else if (reg_info.alt_name)
497                         {
498                             s->Printf("[%s%+lli]", reg_info.alt_name, reg_offset);
499                             break;
500                         }
501                     }
502                 }
503                 s->Printf("DW_OP_breg%i(0x%llx)", reg_num, reg_offset);
504             }
505             break;
506 
507         case DW_OP_regx:                                                    // 0x90 1 ULEB128 register
508             {
509                 uint64_t reg_num = m_data.GetULEB128(&offset);
510                 if (abi)
511                 {
512                     RegisterInfo reg_info;
513                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
514                     {
515                         if (reg_info.name)
516                         {
517                             s->PutCString (reg_info.name);
518                             break;
519                         }
520                         else if (reg_info.alt_name)
521                         {
522                             s->PutCString (reg_info.alt_name);
523                             break;
524                         }
525                     }
526                 }
527                 s->Printf("DW_OP_regx(%llu)", reg_num); break;
528             }
529             break;
530         case DW_OP_fbreg:                                                   // 0x91 1 SLEB128 offset
531             s->Printf("DW_OP_fbreg(%lli)",m_data.GetSLEB128(&offset));
532             break;
533         case DW_OP_bregx:                                                   // 0x92 2 ULEB128 register followed by SLEB128 offset
534             {
535                 uint32_t reg_num = m_data.GetULEB128(&offset);
536                 int64_t reg_offset = m_data.GetSLEB128(&offset);
537                 if (abi)
538                 {
539                     RegisterInfo reg_info;
540                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
541                     {
542                         if (reg_info.name)
543                         {
544                             s->Printf("[%s%+lli]", reg_info.name, reg_offset);
545                             break;
546                         }
547                         else if (reg_info.alt_name)
548                         {
549                             s->Printf("[%s%+lli]", reg_info.alt_name, reg_offset);
550                             break;
551                         }
552                     }
553                 }
554                 s->Printf("DW_OP_bregx(reg=%u,offset=%lli)", reg_num, reg_offset);
555             }
556             break;
557         case DW_OP_piece:                                                   // 0x93 1 ULEB128 size of piece addressed
558             s->Printf("DW_OP_piece(0x%llx)", m_data.GetULEB128(&offset));
559             break;
560         case DW_OP_deref_size:                                              // 0x94 1 1-byte size of data retrieved
561             s->Printf("DW_OP_deref_size(0x%2.2x)", m_data.GetU8(&offset));
562             break;
563         case DW_OP_xderef_size:                                             // 0x95 1 1-byte size of data retrieved
564             s->Printf("DW_OP_xderef_size(0x%2.2x)", m_data.GetU8(&offset));
565             break;
566         case DW_OP_nop: s->PutCString("DW_OP_nop"); break;                                    // 0x96
567         case DW_OP_push_object_address: s->PutCString("DW_OP_push_object_address"); break;    // 0x97 DWARF3
568         case DW_OP_call2:                                                   // 0x98 DWARF3 1 2-byte offset of DIE
569             s->Printf("DW_OP_call2(0x%4.4x)", m_data.GetU16(&offset));
570             break;
571         case DW_OP_call4:                                                   // 0x99 DWARF3 1 4-byte offset of DIE
572             s->Printf("DW_OP_call4(0x%8.8x)", m_data.GetU32(&offset));
573             break;
574         case DW_OP_call_ref:                                                // 0x9a DWARF3 1 4- or 8-byte offset of DIE
575             s->Printf("DW_OP_call_ref(0x%8.8llx)", m_data.GetAddress(&offset));
576             break;
577 //      case DW_OP_form_tls_address: s << "form_tls_address"; break;        // 0x9b DWARF3
578 //      case DW_OP_call_frame_cfa: s << "call_frame_cfa"; break;            // 0x9c DWARF3
579 //      case DW_OP_bit_piece:                                               // 0x9d DWARF3 2
580 //          s->Printf("DW_OP_bit_piece(0x%x, 0x%x)", m_data.GetULEB128(&offset), m_data.GetULEB128(&offset));
581 //          break;
582 //      case DW_OP_lo_user:     s->PutCString("DW_OP_lo_user"); break;                        // 0xe0
583 //      case DW_OP_hi_user:     s->PutCString("DW_OP_hi_user"); break;                        // 0xff
584 //        case DW_OP_APPLE_extern:
585 //            s->Printf("DW_OP_APPLE_extern(%llu)", m_data.GetULEB128(&offset));
586 //            break;
587 //        case DW_OP_APPLE_array_ref:
588 //            s->PutCString("DW_OP_APPLE_array_ref");
589 //            break;
590         case DW_OP_APPLE_uninit:
591             s->PutCString("DW_OP_APPLE_uninit");  // 0xF0
592             break;
593 //        case DW_OP_APPLE_assign:        // 0xF1 - pops value off and assigns it to second item on stack (2nd item must have assignable context)
594 //            s->PutCString("DW_OP_APPLE_assign");
595 //            break;
596 //        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)
597 //            s->PutCString("DW_OP_APPLE_address_of");
598 //            break;
599 //        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)
600 //            s->PutCString("DW_OP_APPLE_value_of");
601 //            break;
602 //        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)
603 //            s->PutCString("DW_OP_APPLE_deref_type");
604 //            break;
605 //        case DW_OP_APPLE_expr_local:    // 0xF5 - ULEB128 expression local index
606 //            s->Printf("DW_OP_APPLE_expr_local(%llu)", m_data.GetULEB128(&offset));
607 //            break;
608 //        case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
609 //            {
610 //                uint8_t float_length = m_data.GetU8(&offset);
611 //                s->Printf("DW_OP_APPLE_constf(<%u> ", float_length);
612 //                m_data.Dump(s, offset, eFormatHex, float_length, 1, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
613 //                s->PutChar(')');
614 //                // Consume the float data
615 //                m_data.GetData(&offset, float_length);
616 //            }
617 //            break;
618 //        case DW_OP_APPLE_scalar_cast:
619 //            s->Printf("DW_OP_APPLE_scalar_cast(%s)", Scalar::GetValueTypeAsCString ((Scalar::Type)m_data.GetU8(&offset)));
620 //            break;
621 //        case DW_OP_APPLE_clang_cast:
622 //            {
623 //                clang::Type *clang_type = (clang::Type *)m_data.GetMaxU64(&offset, sizeof(void*));
624 //                s->Printf("DW_OP_APPLE_clang_cast(%p)", clang_type);
625 //            }
626 //            break;
627 //        case DW_OP_APPLE_clear:
628 //            s->PutCString("DW_OP_APPLE_clear");
629 //            break;
630 //        case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
631 //            s->PutCString("DW_OP_APPLE_error");
632 //            break;
633         }
634     }
635 }
636 
637 void
638 DWARFExpression::SetLocationListSlide (addr_t slide)
639 {
640     m_loclist_slide = slide;
641 }
642 
643 int
644 DWARFExpression::GetRegisterKind ()
645 {
646     return m_reg_kind;
647 }
648 
649 void
650 DWARFExpression::SetRegisterKind (RegisterKind reg_kind)
651 {
652     m_reg_kind = reg_kind;
653 }
654 
655 bool
656 DWARFExpression::IsLocationList() const
657 {
658     return m_loclist_slide != LLDB_INVALID_ADDRESS;
659 }
660 
661 void
662 DWARFExpression::GetDescription (Stream *s, lldb::DescriptionLevel level, addr_t location_list_base_addr, ABI *abi) const
663 {
664     if (IsLocationList())
665     {
666         // We have a location list
667         uint32_t offset = 0;
668         uint32_t count = 0;
669         addr_t curr_base_addr = location_list_base_addr;
670         while (m_data.ValidOffset(offset))
671         {
672             lldb::addr_t begin_addr_offset = m_data.GetAddress(&offset);
673             lldb::addr_t end_addr_offset = m_data.GetAddress(&offset);
674             if (begin_addr_offset < end_addr_offset)
675             {
676                 if (count > 0)
677                     s->PutCString(", ");
678                 VMRange addr_range(curr_base_addr + begin_addr_offset, curr_base_addr + end_addr_offset);
679                 addr_range.Dump(s, 0, 8);
680                 s->PutChar('{');
681                 uint32_t location_length = m_data.GetU16(&offset);
682                 DumpLocation (s, offset, location_length, level, abi);
683                 s->PutChar('}');
684                 offset += location_length;
685             }
686             else if (begin_addr_offset == 0 && end_addr_offset == 0)
687             {
688                 // The end of the location list is marked by both the start and end offset being zero
689                 break;
690             }
691             else
692             {
693                 if ((m_data.GetAddressByteSize() == 4 && (begin_addr_offset == UINT32_MAX)) ||
694                     (m_data.GetAddressByteSize() == 8 && (begin_addr_offset == UINT64_MAX)))
695                 {
696                     curr_base_addr = end_addr_offset + location_list_base_addr;
697                     // We have a new base address
698                     if (count > 0)
699                         s->PutCString(", ");
700                     *s << "base_addr = " << end_addr_offset;
701                 }
702             }
703 
704             count++;
705         }
706     }
707     else
708     {
709         // We have a normal location that contains DW_OP location opcodes
710         DumpLocation (s, 0, m_data.GetByteSize(), level, abi);
711     }
712 }
713 
714 static bool
715 ReadRegisterValueAsScalar
716 (
717     RegisterContext *reg_ctx,
718     uint32_t reg_kind,
719     uint32_t reg_num,
720     Error *error_ptr,
721     Value &value
722 )
723 {
724     if (reg_ctx == NULL)
725     {
726         if (error_ptr)
727             error_ptr->SetErrorStringWithFormat("No register context in frame.\n");
728     }
729     else
730     {
731         uint32_t native_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
732         if (native_reg == LLDB_INVALID_REGNUM)
733         {
734             if (error_ptr)
735                 error_ptr->SetErrorStringWithFormat("Unable to convert register kind=%u reg_num=%u to a native register number.\n", reg_kind, reg_num);
736         }
737         else
738         {
739             const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(native_reg);
740             RegisterValue reg_value;
741             if (reg_ctx->ReadRegister (reg_info, reg_value))
742             {
743                 if (reg_value.GetScalarValue(value.GetScalar()))
744                 {
745                     value.SetValueType (Value::eValueTypeScalar);
746                     value.SetContext (Value::eContextTypeRegisterInfo,
747                                       const_cast<RegisterInfo *>(reg_info));
748                     if (error_ptr)
749                         error_ptr->Clear();
750                     return true;
751                 }
752                 else
753                 {
754                     // If we get this error, then we need to implement a value
755                     // buffer in the dwarf expression evaluation function...
756                     if (error_ptr)
757                         error_ptr->SetErrorStringWithFormat ("register %s can't be converted to a scalar value",
758                                                              reg_info->name);
759                 }
760             }
761             else
762             {
763                 if (error_ptr)
764                     error_ptr->SetErrorStringWithFormat("register %s is not available", reg_info->name);
765             }
766         }
767     }
768     return false;
769 }
770 
771 //bool
772 //DWARFExpression::LocationListContainsLoadAddress (Process* process, const Address &addr) const
773 //{
774 //    return LocationListContainsLoadAddress(process, addr.GetLoadAddress(process));
775 //}
776 //
777 //bool
778 //DWARFExpression::LocationListContainsLoadAddress (Process* process, addr_t load_addr) const
779 //{
780 //    if (load_addr == LLDB_INVALID_ADDRESS)
781 //        return false;
782 //
783 //    if (IsLocationList())
784 //    {
785 //        uint32_t offset = 0;
786 //
787 //        addr_t loc_list_base_addr = m_loclist_slide.GetLoadAddress(process);
788 //
789 //        if (loc_list_base_addr == LLDB_INVALID_ADDRESS)
790 //            return false;
791 //
792 //        while (m_data.ValidOffset(offset))
793 //        {
794 //            // We need to figure out what the value is for the location.
795 //            addr_t lo_pc = m_data.GetAddress(&offset);
796 //            addr_t hi_pc = m_data.GetAddress(&offset);
797 //            if (lo_pc == 0 && hi_pc == 0)
798 //                break;
799 //            else
800 //            {
801 //                lo_pc += loc_list_base_addr;
802 //                hi_pc += loc_list_base_addr;
803 //
804 //                if (lo_pc <= load_addr && load_addr < hi_pc)
805 //                    return true;
806 //
807 //                offset += m_data.GetU16(&offset);
808 //            }
809 //        }
810 //    }
811 //    return false;
812 //}
813 
814 static uint32_t
815 GetOpcodeDataSize (const DataExtractor &data, const uint32_t data_offset, const uint8_t op)
816 {
817     uint32_t offset = data_offset;
818     switch (op)
819     {
820         case DW_OP_addr:
821         case DW_OP_call_ref:    // 0x9a 1 address sized offset of DIE (DWARF3)
822             return data.GetAddressByteSize();
823 
824         // Opcodes with no arguments
825         case DW_OP_deref:   // 0x06
826         case DW_OP_dup:     // 0x12
827         case DW_OP_drop:    // 0x13
828         case DW_OP_over:    // 0x14
829         case DW_OP_swap:    // 0x16
830         case DW_OP_rot:     // 0x17
831         case DW_OP_xderef:  // 0x18
832         case DW_OP_abs:     // 0x19
833         case DW_OP_and:     // 0x1a
834         case DW_OP_div:     // 0x1b
835         case DW_OP_minus:   // 0x1c
836         case DW_OP_mod:     // 0x1d
837         case DW_OP_mul:     // 0x1e
838         case DW_OP_neg:     // 0x1f
839         case DW_OP_not:     // 0x20
840         case DW_OP_or:      // 0x21
841         case DW_OP_plus:    // 0x22
842         case DW_OP_shl:     // 0x24
843         case DW_OP_shr:     // 0x25
844         case DW_OP_shra:    // 0x26
845         case DW_OP_xor:     // 0x27
846         case DW_OP_eq:      // 0x29
847         case DW_OP_ge:      // 0x2a
848         case DW_OP_gt:      // 0x2b
849         case DW_OP_le:      // 0x2c
850         case DW_OP_lt:      // 0x2d
851         case DW_OP_ne:      // 0x2e
852         case DW_OP_lit0:    // 0x30
853         case DW_OP_lit1:    // 0x31
854         case DW_OP_lit2:    // 0x32
855         case DW_OP_lit3:    // 0x33
856         case DW_OP_lit4:    // 0x34
857         case DW_OP_lit5:    // 0x35
858         case DW_OP_lit6:    // 0x36
859         case DW_OP_lit7:    // 0x37
860         case DW_OP_lit8:    // 0x38
861         case DW_OP_lit9:    // 0x39
862         case DW_OP_lit10:   // 0x3A
863         case DW_OP_lit11:   // 0x3B
864         case DW_OP_lit12:   // 0x3C
865         case DW_OP_lit13:   // 0x3D
866         case DW_OP_lit14:   // 0x3E
867         case DW_OP_lit15:   // 0x3F
868         case DW_OP_lit16:   // 0x40
869         case DW_OP_lit17:   // 0x41
870         case DW_OP_lit18:   // 0x42
871         case DW_OP_lit19:   // 0x43
872         case DW_OP_lit20:   // 0x44
873         case DW_OP_lit21:   // 0x45
874         case DW_OP_lit22:   // 0x46
875         case DW_OP_lit23:   // 0x47
876         case DW_OP_lit24:   // 0x48
877         case DW_OP_lit25:   // 0x49
878         case DW_OP_lit26:   // 0x4A
879         case DW_OP_lit27:   // 0x4B
880         case DW_OP_lit28:   // 0x4C
881         case DW_OP_lit29:   // 0x4D
882         case DW_OP_lit30:   // 0x4E
883         case DW_OP_lit31:   // 0x4f
884         case DW_OP_reg0:    // 0x50
885         case DW_OP_reg1:    // 0x51
886         case DW_OP_reg2:    // 0x52
887         case DW_OP_reg3:    // 0x53
888         case DW_OP_reg4:    // 0x54
889         case DW_OP_reg5:    // 0x55
890         case DW_OP_reg6:    // 0x56
891         case DW_OP_reg7:    // 0x57
892         case DW_OP_reg8:    // 0x58
893         case DW_OP_reg9:    // 0x59
894         case DW_OP_reg10:   // 0x5A
895         case DW_OP_reg11:   // 0x5B
896         case DW_OP_reg12:   // 0x5C
897         case DW_OP_reg13:   // 0x5D
898         case DW_OP_reg14:   // 0x5E
899         case DW_OP_reg15:   // 0x5F
900         case DW_OP_reg16:   // 0x60
901         case DW_OP_reg17:   // 0x61
902         case DW_OP_reg18:   // 0x62
903         case DW_OP_reg19:   // 0x63
904         case DW_OP_reg20:   // 0x64
905         case DW_OP_reg21:   // 0x65
906         case DW_OP_reg22:   // 0x66
907         case DW_OP_reg23:   // 0x67
908         case DW_OP_reg24:   // 0x68
909         case DW_OP_reg25:   // 0x69
910         case DW_OP_reg26:   // 0x6A
911         case DW_OP_reg27:   // 0x6B
912         case DW_OP_reg28:   // 0x6C
913         case DW_OP_reg29:   // 0x6D
914         case DW_OP_reg30:   // 0x6E
915         case DW_OP_reg31:   // 0x6F
916         case DW_OP_nop:     // 0x96
917         case DW_OP_push_object_address: // 0x97 DWARF3
918         case DW_OP_form_tls_address:    // 0x9b DWARF3
919         case DW_OP_call_frame_cfa:      // 0x9c DWARF3
920         case DW_OP_stack_value: // 0x9f DWARF4
921             return 0;
922 
923         // Opcodes with a single 1 byte arguments
924         case DW_OP_const1u:     // 0x08 1 1-byte constant
925         case DW_OP_const1s:     // 0x09 1 1-byte constant
926         case DW_OP_pick:        // 0x15 1 1-byte stack index
927         case DW_OP_deref_size:  // 0x94 1 1-byte size of data retrieved
928         case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
929             return 1;
930 
931         // Opcodes with a single 2 byte arguments
932         case DW_OP_const2u:     // 0x0a 1 2-byte constant
933         case DW_OP_const2s:     // 0x0b 1 2-byte constant
934         case DW_OP_skip:        // 0x2f 1 signed 2-byte constant
935         case DW_OP_bra:         // 0x28 1 signed 2-byte constant
936         case DW_OP_call2:       // 0x98 1 2-byte offset of DIE (DWARF3)
937             return 2;
938 
939         // Opcodes with a single 4 byte arguments
940         case DW_OP_const4u:     // 0x0c 1 4-byte constant
941         case DW_OP_const4s:     // 0x0d 1 4-byte constant
942         case DW_OP_call4:       // 0x99 1 4-byte offset of DIE (DWARF3)
943             return 4;
944 
945         // Opcodes with a single 8 byte arguments
946         case DW_OP_const8u:     // 0x0e 1 8-byte constant
947         case DW_OP_const8s:     // 0x0f 1 8-byte constant
948              return 8;
949 
950         // All opcodes that have a single ULEB (signed or unsigned) argument
951         case DW_OP_constu:      // 0x10 1 ULEB128 constant
952         case DW_OP_consts:      // 0x11 1 SLEB128 constant
953         case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
954         case DW_OP_breg0:       // 0x70 1 ULEB128 register
955         case DW_OP_breg1:       // 0x71 1 ULEB128 register
956         case DW_OP_breg2:       // 0x72 1 ULEB128 register
957         case DW_OP_breg3:       // 0x73 1 ULEB128 register
958         case DW_OP_breg4:       // 0x74 1 ULEB128 register
959         case DW_OP_breg5:       // 0x75 1 ULEB128 register
960         case DW_OP_breg6:       // 0x76 1 ULEB128 register
961         case DW_OP_breg7:       // 0x77 1 ULEB128 register
962         case DW_OP_breg8:       // 0x78 1 ULEB128 register
963         case DW_OP_breg9:       // 0x79 1 ULEB128 register
964         case DW_OP_breg10:      // 0x7a 1 ULEB128 register
965         case DW_OP_breg11:      // 0x7b 1 ULEB128 register
966         case DW_OP_breg12:      // 0x7c 1 ULEB128 register
967         case DW_OP_breg13:      // 0x7d 1 ULEB128 register
968         case DW_OP_breg14:      // 0x7e 1 ULEB128 register
969         case DW_OP_breg15:      // 0x7f 1 ULEB128 register
970         case DW_OP_breg16:      // 0x80 1 ULEB128 register
971         case DW_OP_breg17:      // 0x81 1 ULEB128 register
972         case DW_OP_breg18:      // 0x82 1 ULEB128 register
973         case DW_OP_breg19:      // 0x83 1 ULEB128 register
974         case DW_OP_breg20:      // 0x84 1 ULEB128 register
975         case DW_OP_breg21:      // 0x85 1 ULEB128 register
976         case DW_OP_breg22:      // 0x86 1 ULEB128 register
977         case DW_OP_breg23:      // 0x87 1 ULEB128 register
978         case DW_OP_breg24:      // 0x88 1 ULEB128 register
979         case DW_OP_breg25:      // 0x89 1 ULEB128 register
980         case DW_OP_breg26:      // 0x8a 1 ULEB128 register
981         case DW_OP_breg27:      // 0x8b 1 ULEB128 register
982         case DW_OP_breg28:      // 0x8c 1 ULEB128 register
983         case DW_OP_breg29:      // 0x8d 1 ULEB128 register
984         case DW_OP_breg30:      // 0x8e 1 ULEB128 register
985         case DW_OP_breg31:      // 0x8f 1 ULEB128 register
986         case DW_OP_regx:        // 0x90 1 ULEB128 register
987         case DW_OP_fbreg:       // 0x91 1 SLEB128 offset
988         case DW_OP_piece:       // 0x93 1 ULEB128 size of piece addressed
989             data.Skip_LEB128(&offset);
990             return offset - data_offset;
991 
992             // All opcodes that have a 2 ULEB (signed or unsigned) arguments
993         case DW_OP_bregx:       // 0x92 2 ULEB128 register followed by SLEB128 offset
994         case DW_OP_bit_piece:   // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
995             data.Skip_LEB128(&offset);
996             data.Skip_LEB128(&offset);
997             return offset - data_offset;
998 
999         case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size (DWARF4)
1000             {
1001                 uint64_t block_len = data.Skip_LEB128(&offset);
1002                 offset += block_len;
1003                 return offset - data_offset;
1004             }
1005 
1006         default:
1007             break;
1008     }
1009     return UINT32_MAX;
1010 }
1011 
1012 bool
1013 DWARFExpression::LocationContains_DW_OP_addr (lldb::addr_t file_addr, bool &error) const
1014 {
1015     error = false;
1016     if (IsLocationList())
1017         return false;
1018     uint32_t offset = 0;
1019     while (m_data.ValidOffset(offset))
1020     {
1021         const uint8_t op = m_data.GetU8(&offset);
1022 
1023         if (op == DW_OP_addr)
1024         {
1025             if (file_addr == LLDB_INVALID_ADDRESS)
1026                 return true;
1027             addr_t op_file_addr = m_data.GetAddress(&offset);
1028             if (op_file_addr == file_addr)
1029                 return true;
1030         }
1031         else
1032         {
1033             const uint32_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1034             if (op_arg_size == UINT32_MAX)
1035             {
1036                 error = true;
1037                 break;
1038             }
1039             offset += op_arg_size;
1040         }
1041     }
1042     return false;
1043 }
1044 
1045 bool
1046 DWARFExpression::Update_DW_OP_addr (lldb::addr_t file_addr)
1047 {
1048     if (IsLocationList())
1049         return false;
1050     uint32_t offset = 0;
1051     while (m_data.ValidOffset(offset))
1052     {
1053         const uint8_t op = m_data.GetU8(&offset);
1054 
1055         if (op == DW_OP_addr)
1056         {
1057             const uint8_t addr_byte_size = m_data.GetAddressByteSize();
1058             // We have to make a copy of the data as we don't know if this
1059             // data is from a read only memory mapped buffer, so we duplicate
1060             // all of the data first, then modify it, and if all goes well,
1061             // we then replace the data for this expression
1062 
1063             // So first we copy the data into a heap buffer
1064             std::auto_ptr<DataBufferHeap> head_data_ap (new DataBufferHeap (m_data.GetDataStart(),
1065                                                                             m_data.GetByteSize()));
1066 
1067             // Make en encoder so we can write the address into the buffer using
1068             // the correct byte order (endianness)
1069             DataEncoder encoder (head_data_ap->GetBytes(),
1070                                  head_data_ap->GetByteSize(),
1071                                  m_data.GetByteOrder(),
1072                                  addr_byte_size);
1073 
1074             // Replace the address in the new buffer
1075             if (encoder.PutMaxU64 (offset, addr_byte_size, file_addr) == UINT32_MAX)
1076                 return false;
1077 
1078             // All went well, so now we can reset the data using a shared
1079             // pointer to the heap data so "m_data" will now correctly
1080             // manage the heap data.
1081             m_data.SetData (DataBufferSP (head_data_ap.release()));
1082             return true;
1083         }
1084         else
1085         {
1086             const uint32_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1087             if (op_arg_size == UINT32_MAX)
1088                 break;
1089             offset += op_arg_size;
1090         }
1091     }
1092     return false;
1093 }
1094 
1095 bool
1096 DWARFExpression::LocationListContainsAddress (lldb::addr_t loclist_base_addr, lldb::addr_t addr) const
1097 {
1098     if (addr == LLDB_INVALID_ADDRESS)
1099         return false;
1100 
1101     if (IsLocationList())
1102     {
1103         uint32_t offset = 0;
1104 
1105         if (loclist_base_addr == LLDB_INVALID_ADDRESS)
1106             return false;
1107 
1108         while (m_data.ValidOffset(offset))
1109         {
1110             // We need to figure out what the value is for the location.
1111             addr_t lo_pc = m_data.GetAddress(&offset);
1112             addr_t hi_pc = m_data.GetAddress(&offset);
1113             if (lo_pc == 0 && hi_pc == 0)
1114                 break;
1115             else
1116             {
1117                 lo_pc += loclist_base_addr - m_loclist_slide;
1118                 hi_pc += loclist_base_addr - m_loclist_slide;
1119 
1120                 if (lo_pc <= addr && addr < hi_pc)
1121                     return true;
1122 
1123                 offset += m_data.GetU16(&offset);
1124             }
1125         }
1126     }
1127     return false;
1128 }
1129 
1130 bool
1131 DWARFExpression::GetLocation (addr_t base_addr, addr_t pc, uint32_t &offset, uint32_t &length)
1132 {
1133     offset = 0;
1134     if (!IsLocationList())
1135     {
1136         length = m_data.GetByteSize();
1137         return true;
1138     }
1139 
1140     if (base_addr != LLDB_INVALID_ADDRESS && pc != LLDB_INVALID_ADDRESS)
1141     {
1142         addr_t curr_base_addr = base_addr;
1143 
1144         while (m_data.ValidOffset(offset))
1145         {
1146             // We need to figure out what the value is for the location.
1147             addr_t lo_pc = m_data.GetAddress(&offset);
1148             addr_t hi_pc = m_data.GetAddress(&offset);
1149             if (lo_pc == 0 && hi_pc == 0)
1150             {
1151                 break;
1152             }
1153             else
1154             {
1155                 lo_pc += curr_base_addr - m_loclist_slide;
1156                 hi_pc += curr_base_addr - m_loclist_slide;
1157 
1158                 length = m_data.GetU16(&offset);
1159 
1160                 if (length > 0 && lo_pc <= pc && pc < hi_pc)
1161                     return true;
1162 
1163                 offset += length;
1164             }
1165         }
1166     }
1167     offset = UINT32_MAX;
1168     length = 0;
1169     return false;
1170 }
1171 
1172 bool
1173 DWARFExpression::DumpLocationForAddress (Stream *s,
1174                                          lldb::DescriptionLevel level,
1175                                          addr_t base_addr,
1176                                          addr_t address,
1177                                          ABI *abi)
1178 {
1179     uint32_t offset = 0;
1180     uint32_t length = 0;
1181 
1182     if (GetLocation (base_addr, address, offset, length))
1183     {
1184         if (length > 0)
1185         {
1186             DumpLocation(s, offset, length, level, abi);
1187             return true;
1188         }
1189     }
1190     return false;
1191 }
1192 
1193 bool
1194 DWARFExpression::Evaluate
1195 (
1196     ExecutionContextScope *exe_scope,
1197     clang::ASTContext *ast_context,
1198     ClangExpressionVariableList *expr_locals,
1199     ClangExpressionDeclMap *decl_map,
1200     lldb::addr_t loclist_base_load_addr,
1201     const Value* initial_value_ptr,
1202     Value& result,
1203     Error *error_ptr
1204 ) const
1205 {
1206     ExecutionContext exe_ctx (exe_scope);
1207     return Evaluate(&exe_ctx, ast_context, expr_locals, decl_map, NULL, loclist_base_load_addr, initial_value_ptr, result, error_ptr);
1208 }
1209 
1210 bool
1211 DWARFExpression::Evaluate
1212 (
1213     ExecutionContext *exe_ctx,
1214     clang::ASTContext *ast_context,
1215     ClangExpressionVariableList *expr_locals,
1216     ClangExpressionDeclMap *decl_map,
1217     RegisterContext *reg_ctx,
1218     lldb::addr_t loclist_base_load_addr,
1219     const Value* initial_value_ptr,
1220     Value& result,
1221     Error *error_ptr
1222 ) const
1223 {
1224     if (IsLocationList())
1225     {
1226         uint32_t offset = 0;
1227         addr_t pc;
1228         StackFrame *frame = NULL;
1229         if (reg_ctx)
1230             pc = reg_ctx->GetPC();
1231         else
1232         {
1233             frame = exe_ctx->GetFramePtr();
1234             if (!frame)
1235                 return false;
1236             RegisterContextSP reg_ctx_sp = frame->GetRegisterContext();
1237             if (!reg_ctx_sp)
1238                 return false;
1239             pc = reg_ctx_sp->GetPC();
1240         }
1241 
1242         if (loclist_base_load_addr != LLDB_INVALID_ADDRESS)
1243         {
1244             if (pc == LLDB_INVALID_ADDRESS)
1245             {
1246                 if (error_ptr)
1247                     error_ptr->SetErrorString("Invalid PC in frame.");
1248                 return false;
1249             }
1250 
1251             addr_t curr_loclist_base_load_addr = loclist_base_load_addr;
1252 
1253             while (m_data.ValidOffset(offset))
1254             {
1255                 // We need to figure out what the value is for the location.
1256                 addr_t lo_pc = m_data.GetAddress(&offset);
1257                 addr_t hi_pc = m_data.GetAddress(&offset);
1258                 if (lo_pc == 0 && hi_pc == 0)
1259                 {
1260                     break;
1261                 }
1262                 else
1263                 {
1264                     lo_pc += curr_loclist_base_load_addr - m_loclist_slide;
1265                     hi_pc += curr_loclist_base_load_addr - m_loclist_slide;
1266 
1267                     uint16_t length = m_data.GetU16(&offset);
1268 
1269                     if (length > 0 && lo_pc <= pc && pc < hi_pc)
1270                     {
1271                         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);
1272                     }
1273                     offset += length;
1274                 }
1275             }
1276         }
1277         if (error_ptr)
1278             error_ptr->SetErrorString ("variable not available");
1279         return false;
1280     }
1281 
1282     // Not a location list, just a single expression.
1283     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);
1284 }
1285 
1286 
1287 
1288 bool
1289 DWARFExpression::Evaluate
1290 (
1291     ExecutionContext *exe_ctx,
1292     clang::ASTContext *ast_context,
1293     ClangExpressionVariableList *expr_locals,
1294     ClangExpressionDeclMap *decl_map,
1295     RegisterContext *reg_ctx,
1296     const DataExtractor& opcodes,
1297     const uint32_t opcodes_offset,
1298     const uint32_t opcodes_length,
1299     const uint32_t reg_kind,
1300     const Value* initial_value_ptr,
1301     Value& result,
1302     Error *error_ptr
1303 )
1304 {
1305     std::vector<Value> stack;
1306 
1307     Process *process = NULL;
1308     StackFrame *frame = NULL;
1309 
1310     if (exe_ctx)
1311     {
1312         process = exe_ctx->GetProcessPtr();
1313         frame = exe_ctx->GetFramePtr();
1314     }
1315     if (reg_ctx == NULL && frame)
1316         reg_ctx = frame->GetRegisterContext().get();
1317 
1318     if (initial_value_ptr)
1319         stack.push_back(*initial_value_ptr);
1320 
1321     uint32_t offset = opcodes_offset;
1322     const uint32_t end_offset = opcodes_offset + opcodes_length;
1323     Value tmp;
1324     uint32_t reg_num;
1325 
1326     // Make sure all of the data is available in opcodes.
1327     if (!opcodes.ValidOffsetForDataOfSize(opcodes_offset, opcodes_length))
1328     {
1329         if (error_ptr)
1330             error_ptr->SetErrorString ("Invalid offset and/or length for opcodes buffer.");
1331         return false;
1332     }
1333     LogSP log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1334 
1335 
1336     while (opcodes.ValidOffset(offset) && offset < end_offset)
1337     {
1338         const uint32_t op_offset = offset;
1339         const uint8_t op = opcodes.GetU8(&offset);
1340 
1341         if (log && log->GetVerbose())
1342         {
1343             size_t count = stack.size();
1344             log->Printf("Stack before operation has %lu values:", count);
1345             for (size_t i=0; i<count; ++i)
1346             {
1347                 StreamString new_value;
1348                 new_value.Printf("[%zu]", i);
1349                 stack[i].Dump(&new_value);
1350                 log->Printf("  %s", new_value.GetData());
1351             }
1352             log->Printf("0x%8.8x: %s", op_offset, DW_OP_value_to_name(op));
1353         }
1354         switch (op)
1355         {
1356         //----------------------------------------------------------------------
1357         // The DW_OP_addr operation has a single operand that encodes a machine
1358         // address and whose size is the size of an address on the target machine.
1359         //----------------------------------------------------------------------
1360         case DW_OP_addr:
1361             stack.push_back(Scalar(opcodes.GetAddress(&offset)));
1362             stack.back().SetValueType (Value::eValueTypeFileAddress);
1363             break;
1364 
1365         //----------------------------------------------------------------------
1366         // The DW_OP_addr_sect_offset4 is used for any location expressions in
1367         // shared libraries that have a location like:
1368         //  DW_OP_addr(0x1000)
1369         // If this address resides in a shared library, then this virtual
1370         // address won't make sense when it is evaluated in the context of a
1371         // running process where shared libraries have been slid. To account for
1372         // this, this new address type where we can store the section pointer
1373         // and a 4 byte offset.
1374         //----------------------------------------------------------------------
1375 //      case DW_OP_addr_sect_offset4:
1376 //          {
1377 //              result_type = eResultTypeFileAddress;
1378 //              lldb::Section *sect = (lldb::Section *)opcodes.GetMaxU64(&offset, sizeof(void *));
1379 //              lldb::addr_t sect_offset = opcodes.GetU32(&offset);
1380 //
1381 //              Address so_addr (sect, sect_offset);
1382 //              lldb::addr_t load_addr = so_addr.GetLoadAddress();
1383 //              if (load_addr != LLDB_INVALID_ADDRESS)
1384 //              {
1385 //                  // We successfully resolve a file address to a load
1386 //                  // address.
1387 //                  stack.push_back(load_addr);
1388 //                  break;
1389 //              }
1390 //              else
1391 //              {
1392 //                  // We were able
1393 //                  if (error_ptr)
1394 //                      error_ptr->SetErrorStringWithFormat ("Section %s in %s is not currently loaded.\n", sect->GetName().AsCString(), sect->GetModule()->GetFileSpec().GetFilename().AsCString());
1395 //                  return false;
1396 //              }
1397 //          }
1398 //          break;
1399 
1400         //----------------------------------------------------------------------
1401         // OPCODE: DW_OP_deref
1402         // OPERANDS: none
1403         // DESCRIPTION: Pops the top stack entry and treats it as an address.
1404         // The value retrieved from that address is pushed. The size of the
1405         // data retrieved from the dereferenced address is the size of an
1406         // address on the target machine.
1407         //----------------------------------------------------------------------
1408         case DW_OP_deref:
1409             {
1410                 Value::ValueType value_type = stack.back().GetValueType();
1411                 switch (value_type)
1412                 {
1413                 case Value::eValueTypeHostAddress:
1414                     {
1415                         void *src = (void *)stack.back().GetScalar().ULongLong();
1416                         intptr_t ptr;
1417                         ::memcpy (&ptr, src, sizeof(void *));
1418                         stack.back().GetScalar() = ptr;
1419                         stack.back().ClearContext();
1420                     }
1421                     break;
1422                 case Value::eValueTypeLoadAddress:
1423                     if (exe_ctx)
1424                     {
1425                         if (process)
1426                         {
1427                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1428                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1429                             uint32_t addr_size = process->GetAddressByteSize();
1430                             Error error;
1431                             if (process->ReadMemory(pointer_addr, &addr_bytes, addr_size, error) == addr_size)
1432                             {
1433                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), addr_size);
1434                                 uint32_t addr_data_offset = 0;
1435                                 stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1436                                 stack.back().ClearContext();
1437                             }
1438                             else
1439                             {
1440                                 if (error_ptr)
1441                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%llx for DW_OP_deref: %s\n",
1442                                                                          pointer_addr,
1443                                                                          error.AsCString());
1444                                 return false;
1445                             }
1446                         }
1447                         else
1448                         {
1449                             if (error_ptr)
1450                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1451                             return false;
1452                         }
1453                     }
1454                     else
1455                     {
1456                         if (error_ptr)
1457                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1458                         return false;
1459                     }
1460                     break;
1461 
1462                 default:
1463                     break;
1464                 }
1465 
1466             }
1467             break;
1468 
1469         //----------------------------------------------------------------------
1470         // OPCODE: DW_OP_deref_size
1471         // OPERANDS: 1
1472         //  1 - uint8_t that specifies the size of the data to dereference.
1473         // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
1474         // stack entry and treats it as an address. The value retrieved from that
1475         // address is pushed. In the DW_OP_deref_size operation, however, the
1476         // size in bytes of the data retrieved from the dereferenced address is
1477         // specified by the single operand. This operand is a 1-byte unsigned
1478         // integral constant whose value may not be larger than the size of an
1479         // address on the target machine. The data retrieved is zero extended
1480         // to the size of an address on the target machine before being pushed
1481         // on the expression stack.
1482         //----------------------------------------------------------------------
1483         case DW_OP_deref_size:
1484             {
1485                 uint8_t size = opcodes.GetU8(&offset);
1486                 Value::ValueType value_type = stack.back().GetValueType();
1487                 switch (value_type)
1488                 {
1489                 case Value::eValueTypeHostAddress:
1490                     {
1491                         void *src = (void *)stack.back().GetScalar().ULongLong();
1492                         intptr_t ptr;
1493                         ::memcpy (&ptr, src, sizeof(void *));
1494                         // I can't decide whether the size operand should apply to the bytes in their
1495                         // lldb-host endianness or the target endianness.. I doubt this'll ever come up
1496                         // but I'll opt for assuming big endian regardless.
1497                         switch (size)
1498                         {
1499                             case 1: ptr = ptr & 0xff; break;
1500                             case 2: ptr = ptr & 0xffff; break;
1501                             case 3: ptr = ptr & 0xffffff; break;
1502                             case 4: ptr = ptr & 0xffffffff; break;
1503                             // the casts are added to work around the case where intptr_t is a 32 bit quantity;
1504                             // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this program.
1505                             case 5: ptr = (intptr_t) ptr & 0xffffffffffULL; break;
1506                             case 6: ptr = (intptr_t) ptr & 0xffffffffffffULL; break;
1507                             case 7: ptr = (intptr_t) ptr & 0xffffffffffffffULL; break;
1508                             default: break;
1509                         }
1510                         stack.back().GetScalar() = ptr;
1511                         stack.back().ClearContext();
1512                     }
1513                     break;
1514                 case Value::eValueTypeLoadAddress:
1515                     if (exe_ctx)
1516                     {
1517                         if (process)
1518                         {
1519                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1520                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1521                             Error error;
1522                             if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) == size)
1523                             {
1524                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), size);
1525                                 uint32_t addr_data_offset = 0;
1526                                 switch (size)
1527                                 {
1528                                     case 1: stack.back().GetScalar() = addr_data.GetU8(&addr_data_offset); break;
1529                                     case 2: stack.back().GetScalar() = addr_data.GetU16(&addr_data_offset); break;
1530                                     case 4: stack.back().GetScalar() = addr_data.GetU32(&addr_data_offset); break;
1531                                     case 8: stack.back().GetScalar() = addr_data.GetU64(&addr_data_offset); break;
1532                                     default: stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1533                                 }
1534                                 stack.back().ClearContext();
1535                             }
1536                             else
1537                             {
1538                                 if (error_ptr)
1539                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%llx for DW_OP_deref: %s\n",
1540                                                                          pointer_addr,
1541                                                                          error.AsCString());
1542                                 return false;
1543                             }
1544                         }
1545                         else
1546                         {
1547                             if (error_ptr)
1548                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1549                             return false;
1550                         }
1551                     }
1552                     else
1553                     {
1554                         if (error_ptr)
1555                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1556                         return false;
1557                     }
1558                     break;
1559 
1560                 default:
1561                     break;
1562                 }
1563 
1564             }
1565             break;
1566 
1567         //----------------------------------------------------------------------
1568         // OPCODE: DW_OP_xderef_size
1569         // OPERANDS: 1
1570         //  1 - uint8_t that specifies the size of the data to dereference.
1571         // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
1572         // the top of the stack is treated as an address. The second stack
1573         // entry is treated as an "address space identifier" for those
1574         // architectures that support multiple address spaces. The top two
1575         // stack elements are popped, a data item is retrieved through an
1576         // implementation-defined address calculation and pushed as the new
1577         // stack top. In the DW_OP_xderef_size operation, however, the size in
1578         // bytes of the data retrieved from the dereferenced address is
1579         // specified by the single operand. This operand is a 1-byte unsigned
1580         // integral constant whose value may not be larger than the size of an
1581         // address on the target machine. The data retrieved is zero extended
1582         // to the size of an address on the target machine before being pushed
1583         // on the expression stack.
1584         //----------------------------------------------------------------------
1585         case DW_OP_xderef_size:
1586             if (error_ptr)
1587                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
1588             return false;
1589         //----------------------------------------------------------------------
1590         // OPCODE: DW_OP_xderef
1591         // OPERANDS: none
1592         // DESCRIPTION: Provides an extended dereference mechanism. The entry at
1593         // the top of the stack is treated as an address. The second stack entry
1594         // is treated as an "address space identifier" for those architectures
1595         // that support multiple address spaces. The top two stack elements are
1596         // popped, a data item is retrieved through an implementation-defined
1597         // address calculation and pushed as the new stack top. The size of the
1598         // data retrieved from the dereferenced address is the size of an address
1599         // on the target machine.
1600         //----------------------------------------------------------------------
1601         case DW_OP_xderef:
1602             if (error_ptr)
1603                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
1604             return false;
1605 
1606         //----------------------------------------------------------------------
1607         // All DW_OP_constXXX opcodes have a single operand as noted below:
1608         //
1609         // Opcode           Operand 1
1610         // ---------------  ----------------------------------------------------
1611         // DW_OP_const1u    1-byte unsigned integer constant
1612         // DW_OP_const1s    1-byte signed integer constant
1613         // DW_OP_const2u    2-byte unsigned integer constant
1614         // DW_OP_const2s    2-byte signed integer constant
1615         // DW_OP_const4u    4-byte unsigned integer constant
1616         // DW_OP_const4s    4-byte signed integer constant
1617         // DW_OP_const8u    8-byte unsigned integer constant
1618         // DW_OP_const8s    8-byte signed integer constant
1619         // DW_OP_constu     unsigned LEB128 integer constant
1620         // DW_OP_consts     signed LEB128 integer constant
1621         //----------------------------------------------------------------------
1622         case DW_OP_const1u             :    stack.push_back(Scalar(( uint8_t)opcodes.GetU8 (&offset))); break;
1623         case DW_OP_const1s             :    stack.push_back(Scalar((  int8_t)opcodes.GetU8 (&offset))); break;
1624         case DW_OP_const2u             :    stack.push_back(Scalar((uint16_t)opcodes.GetU16 (&offset))); break;
1625         case DW_OP_const2s             :    stack.push_back(Scalar(( int16_t)opcodes.GetU16 (&offset))); break;
1626         case DW_OP_const4u             :    stack.push_back(Scalar((uint32_t)opcodes.GetU32 (&offset))); break;
1627         case DW_OP_const4s             :    stack.push_back(Scalar(( int32_t)opcodes.GetU32 (&offset))); break;
1628         case DW_OP_const8u             :    stack.push_back(Scalar((uint64_t)opcodes.GetU64 (&offset))); break;
1629         case DW_OP_const8s             :    stack.push_back(Scalar(( int64_t)opcodes.GetU64 (&offset))); break;
1630         case DW_OP_constu              :    stack.push_back(Scalar(opcodes.GetULEB128 (&offset))); break;
1631         case DW_OP_consts              :    stack.push_back(Scalar(opcodes.GetSLEB128 (&offset))); break;
1632 
1633         //----------------------------------------------------------------------
1634         // OPCODE: DW_OP_dup
1635         // OPERANDS: none
1636         // DESCRIPTION: duplicates the value at the top of the stack
1637         //----------------------------------------------------------------------
1638         case DW_OP_dup:
1639             if (stack.empty())
1640             {
1641                 if (error_ptr)
1642                     error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
1643                 return false;
1644             }
1645             else
1646                 stack.push_back(stack.back());
1647             break;
1648 
1649         //----------------------------------------------------------------------
1650         // OPCODE: DW_OP_drop
1651         // OPERANDS: none
1652         // DESCRIPTION: pops the value at the top of the stack
1653         //----------------------------------------------------------------------
1654         case DW_OP_drop:
1655             if (stack.empty())
1656             {
1657                 if (error_ptr)
1658                     error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
1659                 return false;
1660             }
1661             else
1662                 stack.pop_back();
1663             break;
1664 
1665         //----------------------------------------------------------------------
1666         // OPCODE: DW_OP_over
1667         // OPERANDS: none
1668         // DESCRIPTION: Duplicates the entry currently second in the stack at
1669         // the top of the stack.
1670         //----------------------------------------------------------------------
1671         case DW_OP_over:
1672             if (stack.size() < 2)
1673             {
1674                 if (error_ptr)
1675                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_over.");
1676                 return false;
1677             }
1678             else
1679                 stack.push_back(stack[stack.size() - 2]);
1680             break;
1681 
1682 
1683         //----------------------------------------------------------------------
1684         // OPCODE: DW_OP_pick
1685         // OPERANDS: uint8_t index into the current stack
1686         // DESCRIPTION: The stack entry with the specified index (0 through 255,
1687         // inclusive) is pushed on the stack
1688         //----------------------------------------------------------------------
1689         case DW_OP_pick:
1690             {
1691                 uint8_t pick_idx = opcodes.GetU8(&offset);
1692                 if (pick_idx < stack.size())
1693                     stack.push_back(stack[pick_idx]);
1694                 else
1695                 {
1696                     if (error_ptr)
1697                         error_ptr->SetErrorStringWithFormat("Index %u out of range for DW_OP_pick.\n", pick_idx);
1698                     return false;
1699                 }
1700             }
1701             break;
1702 
1703         //----------------------------------------------------------------------
1704         // OPCODE: DW_OP_swap
1705         // OPERANDS: none
1706         // DESCRIPTION: swaps the top two stack entries. The entry at the top
1707         // of the stack becomes the second stack entry, and the second entry
1708         // becomes the top of the stack
1709         //----------------------------------------------------------------------
1710         case DW_OP_swap:
1711             if (stack.size() < 2)
1712             {
1713                 if (error_ptr)
1714                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_swap.");
1715                 return false;
1716             }
1717             else
1718             {
1719                 tmp = stack.back();
1720                 stack.back() = stack[stack.size() - 2];
1721                 stack[stack.size() - 2] = tmp;
1722             }
1723             break;
1724 
1725         //----------------------------------------------------------------------
1726         // OPCODE: DW_OP_rot
1727         // OPERANDS: none
1728         // DESCRIPTION: Rotates the first three stack entries. The entry at
1729         // the top of the stack becomes the third stack entry, the second
1730         // entry becomes the top of the stack, and the third entry becomes
1731         // the second entry.
1732         //----------------------------------------------------------------------
1733         case DW_OP_rot:
1734             if (stack.size() < 3)
1735             {
1736                 if (error_ptr)
1737                     error_ptr->SetErrorString("Expression stack needs at least 3 items for DW_OP_rot.");
1738                 return false;
1739             }
1740             else
1741             {
1742                 size_t last_idx = stack.size() - 1;
1743                 Value old_top = stack[last_idx];
1744                 stack[last_idx] = stack[last_idx - 1];
1745                 stack[last_idx - 1] = stack[last_idx - 2];
1746                 stack[last_idx - 2] = old_top;
1747             }
1748             break;
1749 
1750         //----------------------------------------------------------------------
1751         // OPCODE: DW_OP_abs
1752         // OPERANDS: none
1753         // DESCRIPTION: pops the top stack entry, interprets it as a signed
1754         // value and pushes its absolute value. If the absolute value can not be
1755         // represented, the result is undefined.
1756         //----------------------------------------------------------------------
1757         case DW_OP_abs:
1758             if (stack.empty())
1759             {
1760                 if (error_ptr)
1761                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_abs.");
1762                 return false;
1763             }
1764             else if (stack.back().ResolveValue(exe_ctx, ast_context).AbsoluteValue() == false)
1765             {
1766                 if (error_ptr)
1767                     error_ptr->SetErrorString("Failed to take the absolute value of the first stack item.");
1768                 return false;
1769             }
1770             break;
1771 
1772         //----------------------------------------------------------------------
1773         // OPCODE: DW_OP_and
1774         // OPERANDS: none
1775         // DESCRIPTION: pops the top two stack values, performs a bitwise and
1776         // operation on the two, and pushes the result.
1777         //----------------------------------------------------------------------
1778         case DW_OP_and:
1779             if (stack.size() < 2)
1780             {
1781                 if (error_ptr)
1782                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_and.");
1783                 return false;
1784             }
1785             else
1786             {
1787                 tmp = stack.back();
1788                 stack.pop_back();
1789                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) & tmp.ResolveValue(exe_ctx, ast_context);
1790             }
1791             break;
1792 
1793         //----------------------------------------------------------------------
1794         // OPCODE: DW_OP_div
1795         // OPERANDS: none
1796         // DESCRIPTION: pops the top two stack values, divides the former second
1797         // entry by the former top of the stack using signed division, and
1798         // pushes the result.
1799         //----------------------------------------------------------------------
1800         case DW_OP_div:
1801             if (stack.size() < 2)
1802             {
1803                 if (error_ptr)
1804                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_div.");
1805                 return false;
1806             }
1807             else
1808             {
1809                 tmp = stack.back();
1810                 if (tmp.ResolveValue(exe_ctx, ast_context).IsZero())
1811                 {
1812                     if (error_ptr)
1813                         error_ptr->SetErrorString("Divide by zero.");
1814                     return false;
1815                 }
1816                 else
1817                 {
1818                     stack.pop_back();
1819                     stack.back() = stack.back().ResolveValue(exe_ctx, ast_context) / tmp.ResolveValue(exe_ctx, ast_context);
1820                     if (!stack.back().ResolveValue(exe_ctx, ast_context).IsValid())
1821                     {
1822                         if (error_ptr)
1823                             error_ptr->SetErrorString("Divide failed.");
1824                         return false;
1825                     }
1826                 }
1827             }
1828             break;
1829 
1830         //----------------------------------------------------------------------
1831         // OPCODE: DW_OP_minus
1832         // OPERANDS: none
1833         // DESCRIPTION: pops the top two stack values, subtracts the former top
1834         // of the stack from the former second entry, and pushes the result.
1835         //----------------------------------------------------------------------
1836         case DW_OP_minus:
1837             if (stack.size() < 2)
1838             {
1839                 if (error_ptr)
1840                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_minus.");
1841                 return false;
1842             }
1843             else
1844             {
1845                 tmp = stack.back();
1846                 stack.pop_back();
1847                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) - tmp.ResolveValue(exe_ctx, ast_context);
1848             }
1849             break;
1850 
1851         //----------------------------------------------------------------------
1852         // OPCODE: DW_OP_mod
1853         // OPERANDS: none
1854         // DESCRIPTION: pops the top two stack values and pushes the result of
1855         // the calculation: former second stack entry modulo the former top of
1856         // the stack.
1857         //----------------------------------------------------------------------
1858         case DW_OP_mod:
1859             if (stack.size() < 2)
1860             {
1861                 if (error_ptr)
1862                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mod.");
1863                 return false;
1864             }
1865             else
1866             {
1867                 tmp = stack.back();
1868                 stack.pop_back();
1869                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) % tmp.ResolveValue(exe_ctx, ast_context);
1870             }
1871             break;
1872 
1873 
1874         //----------------------------------------------------------------------
1875         // OPCODE: DW_OP_mul
1876         // OPERANDS: none
1877         // DESCRIPTION: pops the top two stack entries, multiplies them
1878         // together, and pushes the result.
1879         //----------------------------------------------------------------------
1880         case DW_OP_mul:
1881             if (stack.size() < 2)
1882             {
1883                 if (error_ptr)
1884                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mul.");
1885                 return false;
1886             }
1887             else
1888             {
1889                 tmp = stack.back();
1890                 stack.pop_back();
1891                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) * tmp.ResolveValue(exe_ctx, ast_context);
1892             }
1893             break;
1894 
1895         //----------------------------------------------------------------------
1896         // OPCODE: DW_OP_neg
1897         // OPERANDS: none
1898         // DESCRIPTION: pops the top stack entry, and pushes its negation.
1899         //----------------------------------------------------------------------
1900         case DW_OP_neg:
1901             if (stack.empty())
1902             {
1903                 if (error_ptr)
1904                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_neg.");
1905                 return false;
1906             }
1907             else
1908             {
1909                 if (stack.back().ResolveValue(exe_ctx, ast_context).UnaryNegate() == false)
1910                 {
1911                     if (error_ptr)
1912                         error_ptr->SetErrorString("Unary negate failed.");
1913                     return false;
1914                 }
1915             }
1916             break;
1917 
1918         //----------------------------------------------------------------------
1919         // OPCODE: DW_OP_not
1920         // OPERANDS: none
1921         // DESCRIPTION: pops the top stack entry, and pushes its bitwise
1922         // complement
1923         //----------------------------------------------------------------------
1924         case DW_OP_not:
1925             if (stack.empty())
1926             {
1927                 if (error_ptr)
1928                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_not.");
1929                 return false;
1930             }
1931             else
1932             {
1933                 if (stack.back().ResolveValue(exe_ctx, ast_context).OnesComplement() == false)
1934                 {
1935                     if (error_ptr)
1936                         error_ptr->SetErrorString("Logical NOT failed.");
1937                     return false;
1938                 }
1939             }
1940             break;
1941 
1942         //----------------------------------------------------------------------
1943         // OPCODE: DW_OP_or
1944         // OPERANDS: none
1945         // DESCRIPTION: pops the top two stack entries, performs a bitwise or
1946         // operation on the two, and pushes the result.
1947         //----------------------------------------------------------------------
1948         case DW_OP_or:
1949             if (stack.size() < 2)
1950             {
1951                 if (error_ptr)
1952                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_or.");
1953                 return false;
1954             }
1955             else
1956             {
1957                 tmp = stack.back();
1958                 stack.pop_back();
1959                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) | tmp.ResolveValue(exe_ctx, ast_context);
1960             }
1961             break;
1962 
1963         //----------------------------------------------------------------------
1964         // OPCODE: DW_OP_plus
1965         // OPERANDS: none
1966         // DESCRIPTION: pops the top two stack entries, adds them together, and
1967         // pushes the result.
1968         //----------------------------------------------------------------------
1969         case DW_OP_plus:
1970             if (stack.size() < 2)
1971             {
1972                 if (error_ptr)
1973                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_plus.");
1974                 return false;
1975             }
1976             else
1977             {
1978                 tmp = stack.back();
1979                 stack.pop_back();
1980                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) + tmp.ResolveValue(exe_ctx, ast_context);
1981             }
1982             break;
1983 
1984         //----------------------------------------------------------------------
1985         // OPCODE: DW_OP_plus_uconst
1986         // OPERANDS: none
1987         // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
1988         // constant operand and pushes the result.
1989         //----------------------------------------------------------------------
1990         case DW_OP_plus_uconst:
1991             if (stack.empty())
1992             {
1993                 if (error_ptr)
1994                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_plus_uconst.");
1995                 return false;
1996             }
1997             else
1998             {
1999                 uint32_t uconst_value = opcodes.GetULEB128(&offset);
2000                 // Implicit conversion from a UINT to a Scalar...
2001                 stack.back().ResolveValue(exe_ctx, ast_context) += uconst_value;
2002                 if (!stack.back().ResolveValue(exe_ctx, ast_context).IsValid())
2003                 {
2004                     if (error_ptr)
2005                         error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
2006                     return false;
2007                 }
2008             }
2009             break;
2010 
2011         //----------------------------------------------------------------------
2012         // OPCODE: DW_OP_shl
2013         // OPERANDS: none
2014         // DESCRIPTION:  pops the top two stack entries, shifts the former
2015         // second entry left by the number of bits specified by the former top
2016         // of the stack, and pushes the result.
2017         //----------------------------------------------------------------------
2018         case DW_OP_shl:
2019             if (stack.size() < 2)
2020             {
2021                 if (error_ptr)
2022                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shl.");
2023                 return false;
2024             }
2025             else
2026             {
2027                 tmp = stack.back();
2028                 stack.pop_back();
2029                 stack.back().ResolveValue(exe_ctx, ast_context) <<= tmp.ResolveValue(exe_ctx, ast_context);
2030             }
2031             break;
2032 
2033         //----------------------------------------------------------------------
2034         // OPCODE: DW_OP_shr
2035         // OPERANDS: none
2036         // DESCRIPTION: pops the top two stack entries, shifts the former second
2037         // entry right logically (filling with zero bits) by the number of bits
2038         // specified by the former top of the stack, and pushes the result.
2039         //----------------------------------------------------------------------
2040         case DW_OP_shr:
2041             if (stack.size() < 2)
2042             {
2043                 if (error_ptr)
2044                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shr.");
2045                 return false;
2046             }
2047             else
2048             {
2049                 tmp = stack.back();
2050                 stack.pop_back();
2051                 if (stack.back().ResolveValue(exe_ctx, ast_context).ShiftRightLogical(tmp.ResolveValue(exe_ctx, ast_context)) == false)
2052                 {
2053                     if (error_ptr)
2054                         error_ptr->SetErrorString("DW_OP_shr failed.");
2055                     return false;
2056                 }
2057             }
2058             break;
2059 
2060         //----------------------------------------------------------------------
2061         // OPCODE: DW_OP_shra
2062         // OPERANDS: none
2063         // DESCRIPTION: pops the top two stack entries, shifts the former second
2064         // entry right arithmetically (divide the magnitude by 2, keep the same
2065         // sign for the result) by the number of bits specified by the former
2066         // top of the stack, and pushes the result.
2067         //----------------------------------------------------------------------
2068         case DW_OP_shra:
2069             if (stack.size() < 2)
2070             {
2071                 if (error_ptr)
2072                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shra.");
2073                 return false;
2074             }
2075             else
2076             {
2077                 tmp = stack.back();
2078                 stack.pop_back();
2079                 stack.back().ResolveValue(exe_ctx, ast_context) >>= tmp.ResolveValue(exe_ctx, ast_context);
2080             }
2081             break;
2082 
2083         //----------------------------------------------------------------------
2084         // OPCODE: DW_OP_xor
2085         // OPERANDS: none
2086         // DESCRIPTION: pops the top two stack entries, performs the bitwise
2087         // exclusive-or operation on the two, and pushes the result.
2088         //----------------------------------------------------------------------
2089         case DW_OP_xor:
2090             if (stack.size() < 2)
2091             {
2092                 if (error_ptr)
2093                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_xor.");
2094                 return false;
2095             }
2096             else
2097             {
2098                 tmp = stack.back();
2099                 stack.pop_back();
2100                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) ^ tmp.ResolveValue(exe_ctx, ast_context);
2101             }
2102             break;
2103 
2104 
2105         //----------------------------------------------------------------------
2106         // OPCODE: DW_OP_skip
2107         // OPERANDS: int16_t
2108         // DESCRIPTION:  An unconditional branch. Its single operand is a 2-byte
2109         // signed integer constant. The 2-byte constant is the number of bytes
2110         // of the DWARF expression to skip forward or backward from the current
2111         // operation, beginning after the 2-byte constant.
2112         //----------------------------------------------------------------------
2113         case DW_OP_skip:
2114             {
2115                 int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
2116                 uint32_t new_offset = offset + skip_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_skip.");
2123                     return false;
2124                 }
2125             }
2126             break;
2127 
2128         //----------------------------------------------------------------------
2129         // OPCODE: DW_OP_bra
2130         // OPERANDS: int16_t
2131         // DESCRIPTION: A conditional branch. Its single operand is a 2-byte
2132         // signed integer constant. This operation pops the top of stack. If
2133         // the value popped is not the constant 0, the 2-byte constant operand
2134         // is the number of bytes of the DWARF expression to skip forward or
2135         // backward from the current operation, beginning after the 2-byte
2136         // constant.
2137         //----------------------------------------------------------------------
2138         case DW_OP_bra:
2139             {
2140                 tmp = stack.back();
2141                 stack.pop_back();
2142                 int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
2143                 Scalar zero(0);
2144                 if (tmp.ResolveValue(exe_ctx, ast_context) != zero)
2145                 {
2146                     uint32_t new_offset = offset + bra_offset;
2147                     if (new_offset >= opcodes_offset && new_offset < end_offset)
2148                         offset = new_offset;
2149                     else
2150                     {
2151                         if (error_ptr)
2152                             error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
2153                         return false;
2154                     }
2155                 }
2156             }
2157             break;
2158 
2159         //----------------------------------------------------------------------
2160         // OPCODE: DW_OP_eq
2161         // OPERANDS: none
2162         // DESCRIPTION: pops the top two stack values, compares using the
2163         // equals (==) operator.
2164         // STACK RESULT: push the constant value 1 onto the stack if the result
2165         // of the operation is true or the constant value 0 if the result of the
2166         // operation is false.
2167         //----------------------------------------------------------------------
2168         case DW_OP_eq:
2169             if (stack.size() < 2)
2170             {
2171                 if (error_ptr)
2172                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_eq.");
2173                 return false;
2174             }
2175             else
2176             {
2177                 tmp = stack.back();
2178                 stack.pop_back();
2179                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) == tmp.ResolveValue(exe_ctx, ast_context);
2180             }
2181             break;
2182 
2183         //----------------------------------------------------------------------
2184         // OPCODE: DW_OP_ge
2185         // OPERANDS: none
2186         // DESCRIPTION: pops the top two stack values, compares using the
2187         // greater than or equal to (>=) operator.
2188         // STACK RESULT: push the constant value 1 onto the stack if the result
2189         // of the operation is true or the constant value 0 if the result of the
2190         // operation is false.
2191         //----------------------------------------------------------------------
2192         case DW_OP_ge:
2193             if (stack.size() < 2)
2194             {
2195                 if (error_ptr)
2196                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ge.");
2197                 return false;
2198             }
2199             else
2200             {
2201                 tmp = stack.back();
2202                 stack.pop_back();
2203                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) >= tmp.ResolveValue(exe_ctx, ast_context);
2204             }
2205             break;
2206 
2207         //----------------------------------------------------------------------
2208         // OPCODE: DW_OP_gt
2209         // OPERANDS: none
2210         // DESCRIPTION: pops the top two stack values, compares using the
2211         // greater than (>) operator.
2212         // STACK RESULT: push the constant value 1 onto the stack if the result
2213         // of the operation is true or the constant value 0 if the result of the
2214         // operation is false.
2215         //----------------------------------------------------------------------
2216         case DW_OP_gt:
2217             if (stack.size() < 2)
2218             {
2219                 if (error_ptr)
2220                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_gt.");
2221                 return false;
2222             }
2223             else
2224             {
2225                 tmp = stack.back();
2226                 stack.pop_back();
2227                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) > tmp.ResolveValue(exe_ctx, ast_context);
2228             }
2229             break;
2230 
2231         //----------------------------------------------------------------------
2232         // OPCODE: DW_OP_le
2233         // OPERANDS: none
2234         // DESCRIPTION: pops the top two stack values, compares using the
2235         // less than or equal to (<=) operator.
2236         // STACK RESULT: push the constant value 1 onto the stack if the result
2237         // of the operation is true or the constant value 0 if the result of the
2238         // operation is false.
2239         //----------------------------------------------------------------------
2240         case DW_OP_le:
2241             if (stack.size() < 2)
2242             {
2243                 if (error_ptr)
2244                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_le.");
2245                 return false;
2246             }
2247             else
2248             {
2249                 tmp = stack.back();
2250                 stack.pop_back();
2251                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) <= tmp.ResolveValue(exe_ctx, ast_context);
2252             }
2253             break;
2254 
2255         //----------------------------------------------------------------------
2256         // OPCODE: DW_OP_lt
2257         // OPERANDS: none
2258         // DESCRIPTION: pops the top two stack values, compares using the
2259         // less than (<) operator.
2260         // STACK RESULT: push the constant value 1 onto the stack if the result
2261         // of the operation is true or the constant value 0 if the result of the
2262         // operation is false.
2263         //----------------------------------------------------------------------
2264         case DW_OP_lt:
2265             if (stack.size() < 2)
2266             {
2267                 if (error_ptr)
2268                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_lt.");
2269                 return false;
2270             }
2271             else
2272             {
2273                 tmp = stack.back();
2274                 stack.pop_back();
2275                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) < tmp.ResolveValue(exe_ctx, ast_context);
2276             }
2277             break;
2278 
2279         //----------------------------------------------------------------------
2280         // OPCODE: DW_OP_ne
2281         // OPERANDS: none
2282         // DESCRIPTION: pops the top two stack values, compares using the
2283         // not equal (!=) operator.
2284         // STACK RESULT: push the constant value 1 onto the stack if the result
2285         // of the operation is true or the constant value 0 if the result of the
2286         // operation is false.
2287         //----------------------------------------------------------------------
2288         case DW_OP_ne:
2289             if (stack.size() < 2)
2290             {
2291                 if (error_ptr)
2292                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ne.");
2293                 return false;
2294             }
2295             else
2296             {
2297                 tmp = stack.back();
2298                 stack.pop_back();
2299                 stack.back().ResolveValue(exe_ctx, ast_context) = stack.back().ResolveValue(exe_ctx, ast_context) != tmp.ResolveValue(exe_ctx, ast_context);
2300             }
2301             break;
2302 
2303         //----------------------------------------------------------------------
2304         // OPCODE: DW_OP_litn
2305         // OPERANDS: none
2306         // DESCRIPTION: encode the unsigned literal values from 0 through 31.
2307         // STACK RESULT: push the unsigned literal constant value onto the top
2308         // of the stack.
2309         //----------------------------------------------------------------------
2310         case DW_OP_lit0:
2311         case DW_OP_lit1:
2312         case DW_OP_lit2:
2313         case DW_OP_lit3:
2314         case DW_OP_lit4:
2315         case DW_OP_lit5:
2316         case DW_OP_lit6:
2317         case DW_OP_lit7:
2318         case DW_OP_lit8:
2319         case DW_OP_lit9:
2320         case DW_OP_lit10:
2321         case DW_OP_lit11:
2322         case DW_OP_lit12:
2323         case DW_OP_lit13:
2324         case DW_OP_lit14:
2325         case DW_OP_lit15:
2326         case DW_OP_lit16:
2327         case DW_OP_lit17:
2328         case DW_OP_lit18:
2329         case DW_OP_lit19:
2330         case DW_OP_lit20:
2331         case DW_OP_lit21:
2332         case DW_OP_lit22:
2333         case DW_OP_lit23:
2334         case DW_OP_lit24:
2335         case DW_OP_lit25:
2336         case DW_OP_lit26:
2337         case DW_OP_lit27:
2338         case DW_OP_lit28:
2339         case DW_OP_lit29:
2340         case DW_OP_lit30:
2341         case DW_OP_lit31:
2342             stack.push_back(Scalar(op - DW_OP_lit0));
2343             break;
2344 
2345         //----------------------------------------------------------------------
2346         // OPCODE: DW_OP_regN
2347         // OPERANDS: none
2348         // DESCRIPTION: Push the value in register n on the top of the stack.
2349         //----------------------------------------------------------------------
2350         case DW_OP_reg0:
2351         case DW_OP_reg1:
2352         case DW_OP_reg2:
2353         case DW_OP_reg3:
2354         case DW_OP_reg4:
2355         case DW_OP_reg5:
2356         case DW_OP_reg6:
2357         case DW_OP_reg7:
2358         case DW_OP_reg8:
2359         case DW_OP_reg9:
2360         case DW_OP_reg10:
2361         case DW_OP_reg11:
2362         case DW_OP_reg12:
2363         case DW_OP_reg13:
2364         case DW_OP_reg14:
2365         case DW_OP_reg15:
2366         case DW_OP_reg16:
2367         case DW_OP_reg17:
2368         case DW_OP_reg18:
2369         case DW_OP_reg19:
2370         case DW_OP_reg20:
2371         case DW_OP_reg21:
2372         case DW_OP_reg22:
2373         case DW_OP_reg23:
2374         case DW_OP_reg24:
2375         case DW_OP_reg25:
2376         case DW_OP_reg26:
2377         case DW_OP_reg27:
2378         case DW_OP_reg28:
2379         case DW_OP_reg29:
2380         case DW_OP_reg30:
2381         case DW_OP_reg31:
2382             {
2383                 reg_num = op - DW_OP_reg0;
2384 
2385                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2386                     stack.push_back(tmp);
2387                 else
2388                     return false;
2389             }
2390             break;
2391         //----------------------------------------------------------------------
2392         // OPCODE: DW_OP_regx
2393         // OPERANDS:
2394         //      ULEB128 literal operand that encodes the register.
2395         // DESCRIPTION: Push the value in register on the top of the stack.
2396         //----------------------------------------------------------------------
2397         case DW_OP_regx:
2398             {
2399                 reg_num = opcodes.GetULEB128(&offset);
2400                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2401                     stack.push_back(tmp);
2402                 else
2403                     return false;
2404             }
2405             break;
2406 
2407         //----------------------------------------------------------------------
2408         // OPCODE: DW_OP_bregN
2409         // OPERANDS:
2410         //      SLEB128 offset from register N
2411         // DESCRIPTION: Value is in memory at the address specified by register
2412         // N plus an offset.
2413         //----------------------------------------------------------------------
2414         case DW_OP_breg0:
2415         case DW_OP_breg1:
2416         case DW_OP_breg2:
2417         case DW_OP_breg3:
2418         case DW_OP_breg4:
2419         case DW_OP_breg5:
2420         case DW_OP_breg6:
2421         case DW_OP_breg7:
2422         case DW_OP_breg8:
2423         case DW_OP_breg9:
2424         case DW_OP_breg10:
2425         case DW_OP_breg11:
2426         case DW_OP_breg12:
2427         case DW_OP_breg13:
2428         case DW_OP_breg14:
2429         case DW_OP_breg15:
2430         case DW_OP_breg16:
2431         case DW_OP_breg17:
2432         case DW_OP_breg18:
2433         case DW_OP_breg19:
2434         case DW_OP_breg20:
2435         case DW_OP_breg21:
2436         case DW_OP_breg22:
2437         case DW_OP_breg23:
2438         case DW_OP_breg24:
2439         case DW_OP_breg25:
2440         case DW_OP_breg26:
2441         case DW_OP_breg27:
2442         case DW_OP_breg28:
2443         case DW_OP_breg29:
2444         case DW_OP_breg30:
2445         case DW_OP_breg31:
2446             {
2447                 reg_num = op - DW_OP_breg0;
2448 
2449                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2450                 {
2451                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2452                     tmp.ResolveValue(exe_ctx, ast_context) += (uint64_t)breg_offset;
2453                     tmp.ClearContext();
2454                     stack.push_back(tmp);
2455                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2456                 }
2457                 else
2458                     return false;
2459             }
2460             break;
2461         //----------------------------------------------------------------------
2462         // OPCODE: DW_OP_bregx
2463         // OPERANDS: 2
2464         //      ULEB128 literal operand that encodes the register.
2465         //      SLEB128 offset from register N
2466         // DESCRIPTION: Value is in memory at the address specified by register
2467         // N plus an offset.
2468         //----------------------------------------------------------------------
2469         case DW_OP_bregx:
2470             {
2471                 reg_num = opcodes.GetULEB128(&offset);
2472 
2473                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2474                 {
2475                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2476                     tmp.ResolveValue(exe_ctx, ast_context) += (uint64_t)breg_offset;
2477                     tmp.ClearContext();
2478                     stack.push_back(tmp);
2479                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2480                 }
2481                 else
2482                     return false;
2483             }
2484             break;
2485 
2486         case DW_OP_fbreg:
2487             if (exe_ctx)
2488             {
2489                 if (frame)
2490                 {
2491                     Scalar value;
2492                     if (frame->GetFrameBaseValue(value, error_ptr))
2493                     {
2494                         int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
2495                         value += fbreg_offset;
2496                         stack.push_back(value);
2497                         stack.back().SetValueType (Value::eValueTypeLoadAddress);
2498                     }
2499                     else
2500                         return false;
2501                 }
2502                 else
2503                 {
2504                     if (error_ptr)
2505                         error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_fbreg opcode.");
2506                     return false;
2507                 }
2508             }
2509             else
2510             {
2511                 if (error_ptr)
2512                     error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_fbreg.\n");
2513                 return false;
2514             }
2515 
2516             break;
2517 
2518         //----------------------------------------------------------------------
2519         // OPCODE: DW_OP_nop
2520         // OPERANDS: none
2521         // DESCRIPTION: A place holder. It has no effect on the location stack
2522         // or any of its values.
2523         //----------------------------------------------------------------------
2524         case DW_OP_nop:
2525             break;
2526 
2527         //----------------------------------------------------------------------
2528         // OPCODE: DW_OP_piece
2529         // OPERANDS: 1
2530         //      ULEB128: byte size of the piece
2531         // DESCRIPTION: The operand describes the size in bytes of the piece of
2532         // the object referenced by the DWARF expression whose result is at the
2533         // top of the stack. If the piece is located in a register, but does not
2534         // occupy the entire register, the placement of the piece within that
2535         // register is defined by the ABI.
2536         //
2537         // Many compilers store a single variable in sets of registers, or store
2538         // a variable partially in memory and partially in registers.
2539         // DW_OP_piece provides a way of describing how large a part of a
2540         // variable a particular DWARF expression refers to.
2541         //----------------------------------------------------------------------
2542         case DW_OP_piece:
2543             if (error_ptr)
2544                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_piece.");
2545             return false;
2546 
2547         //----------------------------------------------------------------------
2548         // OPCODE: DW_OP_push_object_address
2549         // OPERANDS: none
2550         // DESCRIPTION: Pushes the address of the object currently being
2551         // evaluated as part of evaluation of a user presented expression.
2552         // This object may correspond to an independent variable described by
2553         // its own DIE or it may be a component of an array, structure, or class
2554         // whose address has been dynamically determined by an earlier step
2555         // during user expression evaluation.
2556         //----------------------------------------------------------------------
2557         case DW_OP_push_object_address:
2558             if (error_ptr)
2559                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_push_object_address.");
2560             return false;
2561 
2562         //----------------------------------------------------------------------
2563         // OPCODE: DW_OP_call2
2564         // OPERANDS:
2565         //      uint16_t compile unit relative offset of a DIE
2566         // DESCRIPTION: Performs subroutine calls during evaluation
2567         // of a DWARF expression. The operand is the 2-byte unsigned offset
2568         // of a debugging information entry in the current compilation unit.
2569         //
2570         // Operand interpretation is exactly like that for DW_FORM_ref2.
2571         //
2572         // This operation transfers control of DWARF expression evaluation
2573         // to the DW_AT_location attribute of the referenced DIE. If there is
2574         // no such attribute, then there is no effect. Execution of the DWARF
2575         // expression of a DW_AT_location attribute may add to and/or remove from
2576         // values on the stack. Execution returns to the point following the call
2577         // when the end of the attribute is reached. Values on the stack at the
2578         // time of the call may be used as parameters by the called expression
2579         // and values left on the stack by the called expression may be used as
2580         // return values by prior agreement between the calling and called
2581         // expressions.
2582         //----------------------------------------------------------------------
2583         case DW_OP_call2:
2584             if (error_ptr)
2585                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call2.");
2586             return false;
2587         //----------------------------------------------------------------------
2588         // OPCODE: DW_OP_call4
2589         // OPERANDS: 1
2590         //      uint32_t compile unit relative offset of a DIE
2591         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2592         // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset
2593         // of a debugging information entry in  the current compilation unit.
2594         //
2595         // Operand interpretation DW_OP_call4 is exactly like that for
2596         // DW_FORM_ref4.
2597         //
2598         // This operation transfers control of DWARF expression evaluation
2599         // to the DW_AT_location attribute of the referenced DIE. If there is
2600         // no such attribute, then there is no effect. Execution of the DWARF
2601         // expression of a DW_AT_location attribute may add to and/or remove from
2602         // values on the stack. Execution returns to the point following the call
2603         // when the end of the attribute is reached. Values on the stack at the
2604         // time of the call may be used as parameters by the called expression
2605         // and values left on the stack by the called expression may be used as
2606         // return values by prior agreement between the calling and called
2607         // expressions.
2608         //----------------------------------------------------------------------
2609         case DW_OP_call4:
2610             if (error_ptr)
2611                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call4.");
2612             return false;
2613 
2614 #if 0
2615         //----------------------------------------------------------------------
2616         // OPCODE: DW_OP_call_ref
2617         // OPERANDS:
2618         //      uint32_t absolute DIE offset for 32-bit DWARF or a uint64_t
2619         //               absolute DIE offset for 64 bit DWARF.
2620         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2621         // expression. Takes a single operand. In the 32-bit DWARF format, the
2622         // operand is a 4-byte unsigned value; in the 64-bit DWARF format, it
2623         // is an 8-byte unsigned value. The operand is used as the offset of a
2624         // debugging information entry in a .debug_info section which may be
2625         // contained in a shared object for executable other than that
2626         // containing the operator. For references from one shared object or
2627         // executable to another, the relocation must be performed by the
2628         // consumer.
2629         //
2630         // Operand interpretation of DW_OP_call_ref is exactly like that for
2631         // DW_FORM_ref_addr.
2632         //
2633         // This operation transfers control of DWARF expression evaluation
2634         // to the DW_AT_location attribute of the referenced DIE. If there is
2635         // no such attribute, then there is no effect. Execution of the DWARF
2636         // expression of a DW_AT_location attribute may add to and/or remove from
2637         // values on the stack. Execution returns to the point following the call
2638         // when the end of the attribute is reached. Values on the stack at the
2639         // time of the call may be used as parameters by the called expression
2640         // and values left on the stack by the called expression may be used as
2641         // return values by prior agreement between the calling and called
2642         // expressions.
2643         //----------------------------------------------------------------------
2644         case DW_OP_call_ref:
2645             if (error_ptr)
2646                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call_ref.");
2647             return false;
2648 
2649                 //----------------------------------------------------------------------
2650                 // OPCODE: DW_OP_APPLE_array_ref
2651                 // OPERANDS: none
2652                 // DESCRIPTION: Pops a value off the stack and uses it as the array
2653                 // index.  Pops a second value off the stack and uses it as the array
2654                 // itself.  Pushes a value onto the stack representing the element of
2655                 // the array specified by the index.
2656                 //----------------------------------------------------------------------
2657             case DW_OP_APPLE_array_ref:
2658             {
2659                 if (stack.size() < 2)
2660                 {
2661                     if (error_ptr)
2662                         error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_APPLE_array_ref.");
2663                     return false;
2664                 }
2665 
2666                 Value index_val = stack.back();
2667                 stack.pop_back();
2668                 Value array_val = stack.back();
2669                 stack.pop_back();
2670 
2671                 Scalar &index_scalar = index_val.ResolveValue(exe_ctx, ast_context);
2672                 int64_t index = index_scalar.SLongLong(LLONG_MAX);
2673 
2674                 if (index == LLONG_MAX)
2675                 {
2676                     if (error_ptr)
2677                         error_ptr->SetErrorString("Invalid array index.");
2678                     return false;
2679                 }
2680 
2681                 if (array_val.GetContextType() != Value::eContextTypeClangType)
2682                 {
2683                     if (error_ptr)
2684                         error_ptr->SetErrorString("Arrays without Clang types are unhandled at this time.");
2685                     return false;
2686                 }
2687 
2688                 if (array_val.GetValueType() != Value::eValueTypeLoadAddress &&
2689                     array_val.GetValueType() != Value::eValueTypeHostAddress)
2690                 {
2691                     if (error_ptr)
2692                         error_ptr->SetErrorString("Array must be stored in memory.");
2693                     return false;
2694                 }
2695 
2696                 void *array_type = array_val.GetClangType();
2697 
2698                 void *member_type;
2699                 uint64_t size = 0;
2700 
2701                 if ((!ClangASTContext::IsPointerType(array_type, &member_type)) &&
2702                     (!ClangASTContext::IsArrayType(array_type, &member_type, &size)))
2703                 {
2704                     if (error_ptr)
2705                         error_ptr->SetErrorString("Array reference from something that is neither a pointer nor an array.");
2706                     return false;
2707                 }
2708 
2709                 if (size && (index >= size || index < 0))
2710                 {
2711                     if (error_ptr)
2712                         error_ptr->SetErrorStringWithFormat("Out of bounds array access.  %lld is not in [0, %llu]", index, size);
2713                     return false;
2714                 }
2715 
2716                 uint64_t member_bit_size = ClangASTType::GetClangTypeBitWidth(ast_context, member_type);
2717                 uint64_t member_bit_align = ClangASTType::GetTypeBitAlign(ast_context, member_type);
2718                 uint64_t member_bit_incr = ((member_bit_size + member_bit_align - 1) / member_bit_align) * member_bit_align;
2719                 if (member_bit_incr % 8)
2720                 {
2721                     if (error_ptr)
2722                         error_ptr->SetErrorStringWithFormat("Array increment is not byte aligned");
2723                     return false;
2724                 }
2725                 int64_t member_offset = (int64_t)(member_bit_incr / 8) * index;
2726 
2727                 Value member;
2728 
2729                 member.SetContext(Value::eContextTypeClangType, member_type);
2730                 member.SetValueType(array_val.GetValueType());
2731 
2732                 addr_t array_base = (addr_t)array_val.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
2733                 addr_t member_loc = array_base + member_offset;
2734                 member.GetScalar() = (uint64_t)member_loc;
2735 
2736                 stack.push_back(member);
2737             }
2738                 break;
2739 
2740         //----------------------------------------------------------------------
2741         // OPCODE: DW_OP_APPLE_uninit
2742         // OPERANDS: none
2743         // DESCRIPTION: Lets us know that the value is currently not initialized
2744         //----------------------------------------------------------------------
2745         case DW_OP_APPLE_uninit:
2746             //return eResultTypeErrorUninitialized;
2747             break;  // Ignore this as we have seen cases where this value is incorrectly added
2748 
2749         //----------------------------------------------------------------------
2750         // OPCODE: DW_OP_APPLE_assign
2751         // OPERANDS: none
2752         // DESCRIPTION: Pops a value off of the stack and assigns it to the next
2753         // item on the stack which must be something assignable (inferior
2754         // Variable, inferior Type with address, inferior register, or
2755         // expression local variable.
2756         //----------------------------------------------------------------------
2757         case DW_OP_APPLE_assign:
2758             if (stack.size() < 2)
2759             {
2760                 if (error_ptr)
2761                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_APPLE_assign.");
2762                 return false;
2763             }
2764             else
2765             {
2766                 tmp = stack.back();
2767                 stack.pop_back();
2768                 Value::ContextType context_type = stack.back().GetContextType();
2769                 StreamString new_value(Stream::eBinary, 4, lldb::endian::InlHostByteOrder());
2770                 switch (context_type)
2771                 {
2772                 case Value::eContextTypeClangType:
2773                     {
2774                         void *clang_type = stack.back().GetClangType();
2775 
2776                         if (ClangASTContext::IsAggregateType (clang_type))
2777                         {
2778                             Value::ValueType source_value_type = tmp.GetValueType();
2779                             Value::ValueType target_value_type = stack.back().GetValueType();
2780 
2781                             addr_t source_addr = (addr_t)tmp.GetScalar().ULongLong();
2782                             addr_t target_addr = (addr_t)stack.back().GetScalar().ULongLong();
2783 
2784                             size_t byte_size = (ClangASTType::GetClangTypeBitWidth(ast_context, clang_type) + 7) / 8;
2785 
2786                             switch (source_value_type)
2787                             {
2788                             case Value::eValueTypeScalar:
2789                             case Value::eValueTypeFileAddress:
2790                                 break;
2791 
2792                             case Value::eValueTypeLoadAddress:
2793                                 switch (target_value_type)
2794                                 {
2795                                 case Value::eValueTypeLoadAddress:
2796                                     {
2797                                         DataBufferHeap data;
2798                                         data.SetByteSize(byte_size);
2799 
2800                                         Error error;
2801                                         if (process->ReadMemory (source_addr, data.GetBytes(), byte_size, error) != byte_size)
2802                                         {
2803                                             if (error_ptr)
2804                                                 error_ptr->SetErrorStringWithFormat ("Couldn't read a composite type from the target: %s", error.AsCString());
2805                                             return false;
2806                                         }
2807 
2808                                         if (process->WriteMemory (target_addr, data.GetBytes(), byte_size, error) != byte_size)
2809                                         {
2810                                             if (error_ptr)
2811                                                 error_ptr->SetErrorStringWithFormat ("Couldn't write a composite type to the target: %s", error.AsCString());
2812                                             return false;
2813                                         }
2814                                     }
2815                                     break;
2816                                 case Value::eValueTypeHostAddress:
2817                                     if (process->GetByteOrder() != lldb::endian::InlHostByteOrder())
2818                                     {
2819                                         if (error_ptr)
2820                                             error_ptr->SetErrorStringWithFormat ("Copy of composite types between incompatible byte orders is unimplemented");
2821                                         return false;
2822                                     }
2823                                     else
2824                                     {
2825                                         Error error;
2826                                         if (process->ReadMemory (source_addr, (uint8_t*)target_addr, byte_size, error) != byte_size)
2827                                         {
2828                                             if (error_ptr)
2829                                                 error_ptr->SetErrorStringWithFormat ("Couldn't read a composite type from the target: %s", error.AsCString());
2830                                             return false;
2831                                         }
2832                                     }
2833                                     break;
2834                                 default:
2835                                     return false;
2836                                 }
2837                                 break;
2838                             case Value::eValueTypeHostAddress:
2839                                 switch (target_value_type)
2840                                 {
2841                                 case Value::eValueTypeLoadAddress:
2842                                     if (process->GetByteOrder() != lldb::endian::InlHostByteOrder())
2843                                     {
2844                                         if (error_ptr)
2845                                             error_ptr->SetErrorStringWithFormat ("Copy of composite types between incompatible byte orders is unimplemented");
2846                                         return false;
2847                                     }
2848                                     else
2849                                     {
2850                                         Error error;
2851                                         if (process->WriteMemory (target_addr, (uint8_t*)source_addr, byte_size, error) != byte_size)
2852                                         {
2853                                             if (error_ptr)
2854                                                 error_ptr->SetErrorStringWithFormat ("Couldn't write a composite type to the target: %s", error.AsCString());
2855                                             return false;
2856                                         }
2857                                     }
2858                                 case Value::eValueTypeHostAddress:
2859                                     memcpy ((uint8_t*)target_addr, (uint8_t*)source_addr, byte_size);
2860                                     break;
2861                                 default:
2862                                     return false;
2863                                 }
2864                             }
2865                         }
2866                         else
2867                         {
2868                             if (!ClangASTType::SetValueFromScalar (ast_context,
2869                                                                   clang_type,
2870                                                                   tmp.ResolveValue(exe_ctx, ast_context),
2871                                                                   new_value))
2872                             {
2873                                 if (error_ptr)
2874                                     error_ptr->SetErrorStringWithFormat ("Couldn't extract a value from an integral type.\n");
2875                                 return false;
2876                             }
2877 
2878                             Value::ValueType value_type = stack.back().GetValueType();
2879 
2880                             switch (value_type)
2881                             {
2882                             case Value::eValueTypeLoadAddress:
2883                             case Value::eValueTypeHostAddress:
2884                                 {
2885                                     AddressType address_type = (value_type == Value::eValueTypeLoadAddress ? eAddressTypeLoad : eAddressTypeHost);
2886                                     lldb::addr_t addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
2887                                     if (!ClangASTType::WriteToMemory (ast_context,
2888                                                                           clang_type,
2889                                                                           exe_ctx,
2890                                                                           addr,
2891                                                                           address_type,
2892                                                                           new_value))
2893                                     {
2894                                         if (error_ptr)
2895                                             error_ptr->SetErrorStringWithFormat ("Failed to write value to memory at 0x%llx.\n", addr);
2896                                         return false;
2897                                     }
2898                                 }
2899                                 break;
2900 
2901                             default:
2902                                 break;
2903                             }
2904                         }
2905                     }
2906                     break;
2907 
2908                 default:
2909                     if (error_ptr)
2910                         error_ptr->SetErrorString ("Assign failed.");
2911                     return false;
2912                 }
2913             }
2914             break;
2915 
2916         //----------------------------------------------------------------------
2917         // OPCODE: DW_OP_APPLE_address_of
2918         // OPERANDS: none
2919         // DESCRIPTION: Pops a value off of the stack and pushed its address.
2920         // The top item on the stack must be a variable, or already be a memory
2921         // location.
2922         //----------------------------------------------------------------------
2923         case DW_OP_APPLE_address_of:
2924             if (stack.empty())
2925             {
2926                 if (error_ptr)
2927                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_APPLE_address_of.");
2928                 return false;
2929             }
2930             else
2931             {
2932                 Value::ValueType value_type = stack.back().GetValueType();
2933                 switch (value_type)
2934                 {
2935                 default:
2936                 case Value::eValueTypeScalar:      // raw scalar value
2937                     if (error_ptr)
2938                         error_ptr->SetErrorString("Top stack item isn't a memory based object.");
2939                     return false;
2940 
2941                 case Value::eValueTypeLoadAddress: // load address value
2942                 case Value::eValueTypeFileAddress: // file address value
2943                 case Value::eValueTypeHostAddress: // host address value (for memory in the process that is using liblldb)
2944                     // Taking the address of an object reduces it to the address
2945                     // of the value and removes any extra context it had.
2946                     //stack.back().SetValueType(Value::eValueTypeScalar);
2947                     stack.back().ClearContext();
2948                     break;
2949                 }
2950             }
2951             break;
2952 
2953         //----------------------------------------------------------------------
2954         // OPCODE: DW_OP_APPLE_value_of
2955         // OPERANDS: none
2956         // DESCRIPTION: Pops a value off of the stack and pushed its value.
2957         // The top item on the stack must be a variable, expression variable.
2958         //----------------------------------------------------------------------
2959         case DW_OP_APPLE_value_of:
2960             if (stack.empty())
2961             {
2962                 if (error_ptr)
2963                     error_ptr->SetErrorString("Expression stack needs at least 1 items for DW_OP_APPLE_value_of.");
2964                 return false;
2965             }
2966             else if (!stack.back().ValueOf(exe_ctx, ast_context))
2967             {
2968                 if (error_ptr)
2969                     error_ptr->SetErrorString ("Top stack item isn't a valid candidate for DW_OP_APPLE_value_of.");
2970                 return false;
2971             }
2972             break;
2973 
2974         //----------------------------------------------------------------------
2975         // OPCODE: DW_OP_APPLE_deref_type
2976         // OPERANDS: none
2977         // DESCRIPTION: gets the value pointed to by the top stack item
2978         //----------------------------------------------------------------------
2979         case DW_OP_APPLE_deref_type:
2980             {
2981                 if (stack.empty())
2982                 {
2983                     if (error_ptr)
2984                         error_ptr->SetErrorString("Expression stack needs at least 1 items for DW_OP_APPLE_deref_type.");
2985                     return false;
2986                 }
2987 
2988                 tmp = stack.back();
2989                 stack.pop_back();
2990 
2991                 if (tmp.GetContextType() != Value::eContextTypeClangType)
2992                 {
2993                     if (error_ptr)
2994                         error_ptr->SetErrorString("Item at top of expression stack must have a Clang type");
2995                     return false;
2996                 }
2997 
2998                 void *ptr_type = tmp.GetClangType();
2999                 void *target_type;
3000 
3001                 if (!ClangASTContext::IsPointerType(ptr_type, &target_type))
3002                 {
3003                     if (error_ptr)
3004                         error_ptr->SetErrorString("Dereferencing a non-pointer type");
3005                     return false;
3006                 }
3007 
3008                 // TODO do we want all pointers to be dereferenced as load addresses?
3009                 Value::ValueType value_type = tmp.GetValueType();
3010 
3011                 tmp.ResolveValue(exe_ctx, ast_context);
3012 
3013                 tmp.SetValueType(value_type);
3014                 tmp.SetContext(Value::eContextTypeClangType, target_type);
3015 
3016                 stack.push_back(tmp);
3017             }
3018             break;
3019 
3020         //----------------------------------------------------------------------
3021         // OPCODE: DW_OP_APPLE_expr_local
3022         // OPERANDS: ULEB128
3023         // DESCRIPTION: pushes the expression local variable index onto the
3024         // stack and set the appropriate context so we know the stack item is
3025         // an expression local variable index.
3026         //----------------------------------------------------------------------
3027         case DW_OP_APPLE_expr_local:
3028             {
3029                 /*
3030                 uint32_t idx = opcodes.GetULEB128(&offset);
3031                 if (expr_locals == NULL)
3032                 {
3033                     if (error_ptr)
3034                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_expr_local(%u) opcode encountered with no local variable list.\n", idx);
3035                     return false;
3036                 }
3037                 Value *expr_local_variable = expr_locals->GetVariableAtIndex(idx);
3038                 if (expr_local_variable == NULL)
3039                 {
3040                     if (error_ptr)
3041                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_expr_local(%u) with invalid index %u.\n", idx, idx);
3042                     return false;
3043                 }
3044                  // The proxy code has been removed. If it is ever re-added, please
3045                  // use shared pointers or return by value to avoid possible memory
3046                  // leak (there is no leak here, but in general, no returning pointers
3047                  // that must be manually freed please.
3048                 Value *proxy = expr_local_variable->CreateProxy();
3049                 stack.push_back(*proxy);
3050                 delete proxy;
3051                 //stack.back().SetContext (Value::eContextTypeClangType, expr_local_variable->GetClangType());
3052                 */
3053             }
3054             break;
3055 
3056         //----------------------------------------------------------------------
3057         // OPCODE: DW_OP_APPLE_extern
3058         // OPERANDS: ULEB128
3059         // DESCRIPTION: pushes a proxy for the extern object index onto the
3060         // stack.
3061         //----------------------------------------------------------------------
3062         case DW_OP_APPLE_extern:
3063             {
3064                 /*
3065                 uint32_t idx = opcodes.GetULEB128(&offset);
3066                 if (!decl_map)
3067                 {
3068                     if (error_ptr)
3069                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_extern(%u) opcode encountered with no decl map.\n", idx);
3070                     return false;
3071                 }
3072                 Value *extern_var = decl_map->GetValueForIndex(idx);
3073                 if (!extern_var)
3074                 {
3075                     if (error_ptr)
3076                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_extern(%u) with invalid index %u.\n", idx, idx);
3077                     return false;
3078                 }
3079                 // The proxy code has been removed. If it is ever re-added, please
3080                 // use shared pointers or return by value to avoid possible memory
3081                 // leak (there is no leak here, but in general, no returning pointers
3082                 // that must be manually freed please.
3083                 Value *proxy = extern_var->CreateProxy();
3084                 stack.push_back(*proxy);
3085                 delete proxy;
3086                 */
3087             }
3088             break;
3089 
3090         case DW_OP_APPLE_scalar_cast:
3091             if (stack.empty())
3092             {
3093                 if (error_ptr)
3094                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_APPLE_scalar_cast.");
3095                 return false;
3096             }
3097             else
3098             {
3099                 // Simple scalar cast
3100                 if (!stack.back().ResolveValue(exe_ctx, ast_context).Cast((Scalar::Type)opcodes.GetU8(&offset)))
3101                 {
3102                     if (error_ptr)
3103                         error_ptr->SetErrorString("Cast failed.");
3104                     return false;
3105                 }
3106             }
3107             break;
3108 
3109 
3110         case DW_OP_APPLE_clang_cast:
3111             if (stack.empty())
3112             {
3113                 if (error_ptr)
3114                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_APPLE_clang_cast.");
3115                 return false;
3116             }
3117             else
3118             {
3119                 void *clang_type = (void *)opcodes.GetMaxU64(&offset, sizeof(void*));
3120                 stack.back().SetContext (Value::eContextTypeClangType, clang_type);
3121             }
3122             break;
3123         //----------------------------------------------------------------------
3124         // OPCODE: DW_OP_APPLE_constf
3125         // OPERANDS: 1 byte float length, followed by that many bytes containing
3126         // the constant float data.
3127         // DESCRIPTION: Push a float value onto the expression stack.
3128         //----------------------------------------------------------------------
3129         case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
3130             {
3131                 uint8_t float_length = opcodes.GetU8(&offset);
3132                 if (sizeof(float) == float_length)
3133                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetFloat (&offset);
3134                 else if (sizeof(double) == float_length)
3135                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetDouble (&offset);
3136                 else if (sizeof(long double) == float_length)
3137                     tmp.ResolveValue(exe_ctx, ast_context) = opcodes.GetLongDouble (&offset);
3138                 else
3139                 {
3140                     StreamString new_value;
3141                     opcodes.Dump(&new_value, offset, eFormatBytes, 1, float_length, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
3142 
3143                      if (error_ptr)
3144                         error_ptr->SetErrorStringWithFormat ("DW_OP_APPLE_constf(<%u> %s) unsupported float size.\n", float_length, new_value.GetData());
3145                     return false;
3146                }
3147                tmp.SetValueType(Value::eValueTypeScalar);
3148                tmp.ClearContext();
3149                stack.push_back(tmp);
3150             }
3151             break;
3152         //----------------------------------------------------------------------
3153         // OPCODE: DW_OP_APPLE_clear
3154         // OPERANDS: none
3155         // DESCRIPTION: Clears the expression stack.
3156         //----------------------------------------------------------------------
3157         case DW_OP_APPLE_clear:
3158             stack.clear();
3159             break;
3160 
3161         //----------------------------------------------------------------------
3162         // OPCODE: DW_OP_APPLE_error
3163         // OPERANDS: none
3164         // DESCRIPTION: Pops a value off of the stack and pushed its value.
3165         // The top item on the stack must be a variable, expression variable.
3166         //----------------------------------------------------------------------
3167         case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
3168             if (error_ptr)
3169                 error_ptr->SetErrorString ("Generic error.");
3170             return false;
3171 #endif // #if 0
3172 
3173         }
3174     }
3175 
3176     if (stack.empty())
3177     {
3178         if (error_ptr)
3179             error_ptr->SetErrorString ("Stack empty after evaluation.");
3180         return false;
3181     }
3182     else if (log && log->GetVerbose())
3183     {
3184         size_t count = stack.size();
3185         log->Printf("Stack after operation has %lu values:", count);
3186         for (size_t i=0; i<count; ++i)
3187         {
3188             StreamString new_value;
3189             new_value.Printf("[%zu]", i);
3190             stack[i].Dump(&new_value);
3191             log->Printf("  %s", new_value.GetData());
3192         }
3193     }
3194 
3195     result = stack.back();
3196     return true;    // Return true on success
3197 }
3198 
3199