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 #include "lldb/Target/StackID.h"
41 
42 using namespace lldb;
43 using namespace lldb_private;
44 
45 const char *
DW_OP_value_to_name(uint32_t val)46 DW_OP_value_to_name (uint32_t val)
47 {
48   static char invalid[100];
49   switch (val) {
50     case 0x03: return "DW_OP_addr";
51     case 0x06: return "DW_OP_deref";
52     case 0x08: return "DW_OP_const1u";
53     case 0x09: return "DW_OP_const1s";
54     case 0x0a: return "DW_OP_const2u";
55     case 0x0b: return "DW_OP_const2s";
56     case 0x0c: return "DW_OP_const4u";
57     case 0x0d: return "DW_OP_const4s";
58     case 0x0e: return "DW_OP_const8u";
59     case 0x0f: return "DW_OP_const8s";
60     case 0x10: return "DW_OP_constu";
61     case 0x11: return "DW_OP_consts";
62     case 0x12: return "DW_OP_dup";
63     case 0x13: return "DW_OP_drop";
64     case 0x14: return "DW_OP_over";
65     case 0x15: return "DW_OP_pick";
66     case 0x16: return "DW_OP_swap";
67     case 0x17: return "DW_OP_rot";
68     case 0x18: return "DW_OP_xderef";
69     case 0x19: return "DW_OP_abs";
70     case 0x1a: return "DW_OP_and";
71     case 0x1b: return "DW_OP_div";
72     case 0x1c: return "DW_OP_minus";
73     case 0x1d: return "DW_OP_mod";
74     case 0x1e: return "DW_OP_mul";
75     case 0x1f: return "DW_OP_neg";
76     case 0x20: return "DW_OP_not";
77     case 0x21: return "DW_OP_or";
78     case 0x22: return "DW_OP_plus";
79     case 0x23: return "DW_OP_plus_uconst";
80     case 0x24: return "DW_OP_shl";
81     case 0x25: return "DW_OP_shr";
82     case 0x26: return "DW_OP_shra";
83     case 0x27: return "DW_OP_xor";
84     case 0x2f: return "DW_OP_skip";
85     case 0x28: return "DW_OP_bra";
86     case 0x29: return "DW_OP_eq";
87     case 0x2a: return "DW_OP_ge";
88     case 0x2b: return "DW_OP_gt";
89     case 0x2c: return "DW_OP_le";
90     case 0x2d: return "DW_OP_lt";
91     case 0x2e: return "DW_OP_ne";
92     case 0x30: return "DW_OP_lit0";
93     case 0x31: return "DW_OP_lit1";
94     case 0x32: return "DW_OP_lit2";
95     case 0x33: return "DW_OP_lit3";
96     case 0x34: return "DW_OP_lit4";
97     case 0x35: return "DW_OP_lit5";
98     case 0x36: return "DW_OP_lit6";
99     case 0x37: return "DW_OP_lit7";
100     case 0x38: return "DW_OP_lit8";
101     case 0x39: return "DW_OP_lit9";
102     case 0x3a: return "DW_OP_lit10";
103     case 0x3b: return "DW_OP_lit11";
104     case 0x3c: return "DW_OP_lit12";
105     case 0x3d: return "DW_OP_lit13";
106     case 0x3e: return "DW_OP_lit14";
107     case 0x3f: return "DW_OP_lit15";
108     case 0x40: return "DW_OP_lit16";
109     case 0x41: return "DW_OP_lit17";
110     case 0x42: return "DW_OP_lit18";
111     case 0x43: return "DW_OP_lit19";
112     case 0x44: return "DW_OP_lit20";
113     case 0x45: return "DW_OP_lit21";
114     case 0x46: return "DW_OP_lit22";
115     case 0x47: return "DW_OP_lit23";
116     case 0x48: return "DW_OP_lit24";
117     case 0x49: return "DW_OP_lit25";
118     case 0x4a: return "DW_OP_lit26";
119     case 0x4b: return "DW_OP_lit27";
120     case 0x4c: return "DW_OP_lit28";
121     case 0x4d: return "DW_OP_lit29";
122     case 0x4e: return "DW_OP_lit30";
123     case 0x4f: return "DW_OP_lit31";
124     case 0x50: return "DW_OP_reg0";
125     case 0x51: return "DW_OP_reg1";
126     case 0x52: return "DW_OP_reg2";
127     case 0x53: return "DW_OP_reg3";
128     case 0x54: return "DW_OP_reg4";
129     case 0x55: return "DW_OP_reg5";
130     case 0x56: return "DW_OP_reg6";
131     case 0x57: return "DW_OP_reg7";
132     case 0x58: return "DW_OP_reg8";
133     case 0x59: return "DW_OP_reg9";
134     case 0x5a: return "DW_OP_reg10";
135     case 0x5b: return "DW_OP_reg11";
136     case 0x5c: return "DW_OP_reg12";
137     case 0x5d: return "DW_OP_reg13";
138     case 0x5e: return "DW_OP_reg14";
139     case 0x5f: return "DW_OP_reg15";
140     case 0x60: return "DW_OP_reg16";
141     case 0x61: return "DW_OP_reg17";
142     case 0x62: return "DW_OP_reg18";
143     case 0x63: return "DW_OP_reg19";
144     case 0x64: return "DW_OP_reg20";
145     case 0x65: return "DW_OP_reg21";
146     case 0x66: return "DW_OP_reg22";
147     case 0x67: return "DW_OP_reg23";
148     case 0x68: return "DW_OP_reg24";
149     case 0x69: return "DW_OP_reg25";
150     case 0x6a: return "DW_OP_reg26";
151     case 0x6b: return "DW_OP_reg27";
152     case 0x6c: return "DW_OP_reg28";
153     case 0x6d: return "DW_OP_reg29";
154     case 0x6e: return "DW_OP_reg30";
155     case 0x6f: return "DW_OP_reg31";
156     case 0x70: return "DW_OP_breg0";
157     case 0x71: return "DW_OP_breg1";
158     case 0x72: return "DW_OP_breg2";
159     case 0x73: return "DW_OP_breg3";
160     case 0x74: return "DW_OP_breg4";
161     case 0x75: return "DW_OP_breg5";
162     case 0x76: return "DW_OP_breg6";
163     case 0x77: return "DW_OP_breg7";
164     case 0x78: return "DW_OP_breg8";
165     case 0x79: return "DW_OP_breg9";
166     case 0x7a: return "DW_OP_breg10";
167     case 0x7b: return "DW_OP_breg11";
168     case 0x7c: return "DW_OP_breg12";
169     case 0x7d: return "DW_OP_breg13";
170     case 0x7e: return "DW_OP_breg14";
171     case 0x7f: return "DW_OP_breg15";
172     case 0x80: return "DW_OP_breg16";
173     case 0x81: return "DW_OP_breg17";
174     case 0x82: return "DW_OP_breg18";
175     case 0x83: return "DW_OP_breg19";
176     case 0x84: return "DW_OP_breg20";
177     case 0x85: return "DW_OP_breg21";
178     case 0x86: return "DW_OP_breg22";
179     case 0x87: return "DW_OP_breg23";
180     case 0x88: return "DW_OP_breg24";
181     case 0x89: return "DW_OP_breg25";
182     case 0x8a: return "DW_OP_breg26";
183     case 0x8b: return "DW_OP_breg27";
184     case 0x8c: return "DW_OP_breg28";
185     case 0x8d: return "DW_OP_breg29";
186     case 0x8e: return "DW_OP_breg30";
187     case 0x8f: return "DW_OP_breg31";
188     case 0x90: return "DW_OP_regx";
189     case 0x91: return "DW_OP_fbreg";
190     case 0x92: return "DW_OP_bregx";
191     case 0x93: return "DW_OP_piece";
192     case 0x94: return "DW_OP_deref_size";
193     case 0x95: return "DW_OP_xderef_size";
194     case 0x96: return "DW_OP_nop";
195     case 0x97: return "DW_OP_push_object_address";
196     case 0x98: return "DW_OP_call2";
197     case 0x99: return "DW_OP_call4";
198     case 0x9a: return "DW_OP_call_ref";
199 //    case DW_OP_APPLE_array_ref: return "DW_OP_APPLE_array_ref";
200 //    case DW_OP_APPLE_extern: return "DW_OP_APPLE_extern";
201     case DW_OP_APPLE_uninit: return "DW_OP_APPLE_uninit";
202 //    case DW_OP_APPLE_assign: return "DW_OP_APPLE_assign";
203 //    case DW_OP_APPLE_address_of: return "DW_OP_APPLE_address_of";
204 //    case DW_OP_APPLE_value_of: return "DW_OP_APPLE_value_of";
205 //    case DW_OP_APPLE_deref_type: return "DW_OP_APPLE_deref_type";
206 //    case DW_OP_APPLE_expr_local: return "DW_OP_APPLE_expr_local";
207 //    case DW_OP_APPLE_constf: return "DW_OP_APPLE_constf";
208 //    case DW_OP_APPLE_scalar_cast: return "DW_OP_APPLE_scalar_cast";
209 //    case DW_OP_APPLE_clang_cast: return "DW_OP_APPLE_clang_cast";
210 //    case DW_OP_APPLE_clear: return "DW_OP_APPLE_clear";
211 //    case DW_OP_APPLE_error: return "DW_OP_APPLE_error";
212     default:
213        snprintf (invalid, sizeof(invalid), "Unknown DW_OP constant: 0x%x", val);
214        return invalid;
215   }
216 }
217 
218 
219 //----------------------------------------------------------------------
220 // DWARFExpression constructor
221 //----------------------------------------------------------------------
DWARFExpression()222 DWARFExpression::DWARFExpression() :
223     m_data(),
224     m_reg_kind (eRegisterKindDWARF),
225     m_loclist_slide (LLDB_INVALID_ADDRESS)
226 {
227 }
228 
DWARFExpression(const DWARFExpression & rhs)229 DWARFExpression::DWARFExpression(const DWARFExpression& rhs) :
230     m_data(rhs.m_data),
231     m_reg_kind (rhs.m_reg_kind),
232     m_loclist_slide(rhs.m_loclist_slide)
233 {
234 }
235 
236 
DWARFExpression(const DataExtractor & data,lldb::offset_t data_offset,lldb::offset_t data_length)237 DWARFExpression::DWARFExpression(const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length) :
238     m_data(data, data_offset, data_length),
239     m_reg_kind (eRegisterKindDWARF),
240     m_loclist_slide(LLDB_INVALID_ADDRESS)
241 {
242 }
243 
244 //----------------------------------------------------------------------
245 // Destructor
246 //----------------------------------------------------------------------
~DWARFExpression()247 DWARFExpression::~DWARFExpression()
248 {
249 }
250 
251 
252 bool
IsValid() const253 DWARFExpression::IsValid() const
254 {
255     return m_data.GetByteSize() > 0;
256 }
257 
258 void
SetOpcodeData(const DataExtractor & data)259 DWARFExpression::SetOpcodeData (const DataExtractor& data)
260 {
261     m_data = data;
262 }
263 
264 void
CopyOpcodeData(const DataExtractor & data,lldb::offset_t data_offset,lldb::offset_t data_length)265 DWARFExpression::CopyOpcodeData (const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length)
266 {
267     const uint8_t *bytes = data.PeekData(data_offset, data_length);
268     if (bytes)
269     {
270         m_data.SetData(DataBufferSP(new DataBufferHeap(bytes, data_length)));
271         m_data.SetByteOrder(data.GetByteOrder());
272         m_data.SetAddressByteSize(data.GetAddressByteSize());
273     }
274 }
275 
276 void
SetOpcodeData(const DataExtractor & data,lldb::offset_t data_offset,lldb::offset_t data_length)277 DWARFExpression::SetOpcodeData (const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length)
278 {
279     m_data.SetData(data, data_offset, data_length);
280 }
281 
282 void
DumpLocation(Stream * s,lldb::offset_t offset,lldb::offset_t length,lldb::DescriptionLevel level,ABI * abi) const283 DWARFExpression::DumpLocation (Stream *s, lldb::offset_t offset, lldb::offset_t length, lldb::DescriptionLevel level, ABI *abi) const
284 {
285     if (!m_data.ValidOffsetForDataOfSize(offset, length))
286         return;
287     const lldb::offset_t start_offset = offset;
288     const lldb::offset_t end_offset = offset + length;
289     while (m_data.ValidOffset(offset) && offset < end_offset)
290     {
291         const lldb::offset_t op_offset = offset;
292         const uint8_t op = m_data.GetU8(&offset);
293 
294         switch (level)
295         {
296         default:
297             break;
298 
299         case lldb::eDescriptionLevelBrief:
300             if (offset > start_offset)
301                 s->PutChar(' ');
302             break;
303 
304         case lldb::eDescriptionLevelFull:
305         case lldb::eDescriptionLevelVerbose:
306             if (offset > start_offset)
307                 s->EOL();
308             s->Indent();
309             if (level == lldb::eDescriptionLevelFull)
310                 break;
311             // Fall through for verbose and print offset and DW_OP prefix..
312             s->Printf("0x%8.8" PRIx64 ": %s", op_offset, op >= DW_OP_APPLE_uninit ? "DW_OP_APPLE_" : "DW_OP_");
313             break;
314         }
315 
316         switch (op)
317         {
318         case DW_OP_addr:    *s << "DW_OP_addr(" << m_data.GetAddress(&offset) << ") "; break;         // 0x03 1 address
319         case DW_OP_deref:   *s << "DW_OP_deref"; break;                                               // 0x06
320         case DW_OP_const1u: s->Printf("DW_OP_const1u(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x08 1 1-byte constant
321         case DW_OP_const1s: s->Printf("DW_OP_const1s(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x09 1 1-byte constant
322         case DW_OP_const2u: s->Printf("DW_OP_const2u(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0a 1 2-byte constant
323         case DW_OP_const2s: s->Printf("DW_OP_const2s(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0b 1 2-byte constant
324         case DW_OP_const4u: s->Printf("DW_OP_const4u(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0c 1 4-byte constant
325         case DW_OP_const4s: s->Printf("DW_OP_const4s(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0d 1 4-byte constant
326         case DW_OP_const8u: s->Printf("DW_OP_const8u(0x%16.16" PRIx64 ") ", m_data.GetU64(&offset)); break;  // 0x0e 1 8-byte constant
327         case DW_OP_const8s: s->Printf("DW_OP_const8s(0x%16.16" PRIx64 ") ", m_data.GetU64(&offset)); break;  // 0x0f 1 8-byte constant
328         case DW_OP_constu:  s->Printf("DW_OP_constu(0x%" PRIx64 ") ", m_data.GetULEB128(&offset)); break;    // 0x10 1 ULEB128 constant
329         case DW_OP_consts:  s->Printf("DW_OP_consts(0x%" PRId64 ") ", m_data.GetSLEB128(&offset)); break;    // 0x11 1 SLEB128 constant
330         case DW_OP_dup:     s->PutCString("DW_OP_dup"); break;                                        // 0x12
331         case DW_OP_drop:    s->PutCString("DW_OP_drop"); break;                                       // 0x13
332         case DW_OP_over:    s->PutCString("DW_OP_over"); break;                                       // 0x14
333         case DW_OP_pick:    s->Printf("DW_OP_pick(0x%2.2x) ", m_data.GetU8(&offset)); break;          // 0x15 1 1-byte stack index
334         case DW_OP_swap:    s->PutCString("DW_OP_swap"); break;                                       // 0x16
335         case DW_OP_rot:     s->PutCString("DW_OP_rot"); break;                                        // 0x17
336         case DW_OP_xderef:  s->PutCString("DW_OP_xderef"); break;                                     // 0x18
337         case DW_OP_abs:     s->PutCString("DW_OP_abs"); break;                                        // 0x19
338         case DW_OP_and:     s->PutCString("DW_OP_and"); break;                                        // 0x1a
339         case DW_OP_div:     s->PutCString("DW_OP_div"); break;                                        // 0x1b
340         case DW_OP_minus:   s->PutCString("DW_OP_minus"); break;                                      // 0x1c
341         case DW_OP_mod:     s->PutCString("DW_OP_mod"); break;                                        // 0x1d
342         case DW_OP_mul:     s->PutCString("DW_OP_mul"); break;                                        // 0x1e
343         case DW_OP_neg:     s->PutCString("DW_OP_neg"); break;                                        // 0x1f
344         case DW_OP_not:     s->PutCString("DW_OP_not"); break;                                        // 0x20
345         case DW_OP_or:      s->PutCString("DW_OP_or"); break;                                         // 0x21
346         case DW_OP_plus:    s->PutCString("DW_OP_plus"); break;                                       // 0x22
347         case DW_OP_plus_uconst:                                                                 // 0x23 1 ULEB128 addend
348             s->Printf("DW_OP_plus_uconst(0x%" PRIx64 ") ", m_data.GetULEB128(&offset));
349             break;
350 
351         case DW_OP_shl:     s->PutCString("DW_OP_shl"); break;                                        // 0x24
352         case DW_OP_shr:     s->PutCString("DW_OP_shr"); break;                                        // 0x25
353         case DW_OP_shra:    s->PutCString("DW_OP_shra"); break;                                       // 0x26
354         case DW_OP_xor:     s->PutCString("DW_OP_xor"); break;                                        // 0x27
355         case DW_OP_skip:    s->Printf("DW_OP_skip(0x%4.4x)", m_data.GetU16(&offset)); break;          // 0x2f 1 signed 2-byte constant
356         case DW_OP_bra:     s->Printf("DW_OP_bra(0x%4.4x)", m_data.GetU16(&offset)); break;           // 0x28 1 signed 2-byte constant
357         case DW_OP_eq:      s->PutCString("DW_OP_eq"); break;                                         // 0x29
358         case DW_OP_ge:      s->PutCString("DW_OP_ge"); break;                                         // 0x2a
359         case DW_OP_gt:      s->PutCString("DW_OP_gt"); break;                                         // 0x2b
360         case DW_OP_le:      s->PutCString("DW_OP_le"); break;                                         // 0x2c
361         case DW_OP_lt:      s->PutCString("DW_OP_lt"); break;                                         // 0x2d
362         case DW_OP_ne:      s->PutCString("DW_OP_ne"); break;                                         // 0x2e
363 
364         case DW_OP_lit0:    // 0x30
365         case DW_OP_lit1:    // 0x31
366         case DW_OP_lit2:    // 0x32
367         case DW_OP_lit3:    // 0x33
368         case DW_OP_lit4:    // 0x34
369         case DW_OP_lit5:    // 0x35
370         case DW_OP_lit6:    // 0x36
371         case DW_OP_lit7:    // 0x37
372         case DW_OP_lit8:    // 0x38
373         case DW_OP_lit9:    // 0x39
374         case DW_OP_lit10:   // 0x3A
375         case DW_OP_lit11:   // 0x3B
376         case DW_OP_lit12:   // 0x3C
377         case DW_OP_lit13:   // 0x3D
378         case DW_OP_lit14:   // 0x3E
379         case DW_OP_lit15:   // 0x3F
380         case DW_OP_lit16:   // 0x40
381         case DW_OP_lit17:   // 0x41
382         case DW_OP_lit18:   // 0x42
383         case DW_OP_lit19:   // 0x43
384         case DW_OP_lit20:   // 0x44
385         case DW_OP_lit21:   // 0x45
386         case DW_OP_lit22:   // 0x46
387         case DW_OP_lit23:   // 0x47
388         case DW_OP_lit24:   // 0x48
389         case DW_OP_lit25:   // 0x49
390         case DW_OP_lit26:   // 0x4A
391         case DW_OP_lit27:   // 0x4B
392         case DW_OP_lit28:   // 0x4C
393         case DW_OP_lit29:   // 0x4D
394         case DW_OP_lit30:   // 0x4E
395         case DW_OP_lit31:   s->Printf("DW_OP_lit%i", op - DW_OP_lit0); break; // 0x4f
396 
397         case DW_OP_reg0:    // 0x50
398         case DW_OP_reg1:    // 0x51
399         case DW_OP_reg2:    // 0x52
400         case DW_OP_reg3:    // 0x53
401         case DW_OP_reg4:    // 0x54
402         case DW_OP_reg5:    // 0x55
403         case DW_OP_reg6:    // 0x56
404         case DW_OP_reg7:    // 0x57
405         case DW_OP_reg8:    // 0x58
406         case DW_OP_reg9:    // 0x59
407         case DW_OP_reg10:   // 0x5A
408         case DW_OP_reg11:   // 0x5B
409         case DW_OP_reg12:   // 0x5C
410         case DW_OP_reg13:   // 0x5D
411         case DW_OP_reg14:   // 0x5E
412         case DW_OP_reg15:   // 0x5F
413         case DW_OP_reg16:   // 0x60
414         case DW_OP_reg17:   // 0x61
415         case DW_OP_reg18:   // 0x62
416         case DW_OP_reg19:   // 0x63
417         case DW_OP_reg20:   // 0x64
418         case DW_OP_reg21:   // 0x65
419         case DW_OP_reg22:   // 0x66
420         case DW_OP_reg23:   // 0x67
421         case DW_OP_reg24:   // 0x68
422         case DW_OP_reg25:   // 0x69
423         case DW_OP_reg26:   // 0x6A
424         case DW_OP_reg27:   // 0x6B
425         case DW_OP_reg28:   // 0x6C
426         case DW_OP_reg29:   // 0x6D
427         case DW_OP_reg30:   // 0x6E
428         case DW_OP_reg31:   // 0x6F
429             {
430                 uint32_t reg_num = op - DW_OP_reg0;
431                 if (abi)
432                 {
433                     RegisterInfo reg_info;
434                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
435                     {
436                         if (reg_info.name)
437                         {
438                             s->PutCString (reg_info.name);
439                             break;
440                         }
441                         else if (reg_info.alt_name)
442                         {
443                             s->PutCString (reg_info.alt_name);
444                             break;
445                         }
446                     }
447                 }
448                 s->Printf("DW_OP_reg%u", reg_num); break;
449             }
450             break;
451 
452         case DW_OP_breg0:
453         case DW_OP_breg1:
454         case DW_OP_breg2:
455         case DW_OP_breg3:
456         case DW_OP_breg4:
457         case DW_OP_breg5:
458         case DW_OP_breg6:
459         case DW_OP_breg7:
460         case DW_OP_breg8:
461         case DW_OP_breg9:
462         case DW_OP_breg10:
463         case DW_OP_breg11:
464         case DW_OP_breg12:
465         case DW_OP_breg13:
466         case DW_OP_breg14:
467         case DW_OP_breg15:
468         case DW_OP_breg16:
469         case DW_OP_breg17:
470         case DW_OP_breg18:
471         case DW_OP_breg19:
472         case DW_OP_breg20:
473         case DW_OP_breg21:
474         case DW_OP_breg22:
475         case DW_OP_breg23:
476         case DW_OP_breg24:
477         case DW_OP_breg25:
478         case DW_OP_breg26:
479         case DW_OP_breg27:
480         case DW_OP_breg28:
481         case DW_OP_breg29:
482         case DW_OP_breg30:
483         case DW_OP_breg31:
484             {
485                 uint32_t reg_num = op - DW_OP_breg0;
486                 int64_t reg_offset = m_data.GetSLEB128(&offset);
487                 if (abi)
488                 {
489                     RegisterInfo reg_info;
490                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
491                     {
492                         if (reg_info.name)
493                         {
494                             s->Printf("[%s%+" PRIi64 "]", reg_info.name, reg_offset);
495                             break;
496                         }
497                         else if (reg_info.alt_name)
498                         {
499                             s->Printf("[%s%+" PRIi64 "]", reg_info.alt_name, reg_offset);
500                             break;
501                         }
502                     }
503                 }
504                 s->Printf("DW_OP_breg%i(0x%" PRIx64 ")", reg_num, reg_offset);
505             }
506             break;
507 
508         case DW_OP_regx:                                                    // 0x90 1 ULEB128 register
509             {
510                 uint32_t reg_num = m_data.GetULEB128(&offset);
511                 if (abi)
512                 {
513                     RegisterInfo reg_info;
514                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
515                     {
516                         if (reg_info.name)
517                         {
518                             s->PutCString (reg_info.name);
519                             break;
520                         }
521                         else if (reg_info.alt_name)
522                         {
523                             s->PutCString (reg_info.alt_name);
524                             break;
525                         }
526                     }
527                 }
528                 s->Printf("DW_OP_regx(%" PRIu32 ")", reg_num); break;
529             }
530             break;
531         case DW_OP_fbreg:                                                   // 0x91 1 SLEB128 offset
532             s->Printf("DW_OP_fbreg(%" PRIi64 ")",m_data.GetSLEB128(&offset));
533             break;
534         case DW_OP_bregx:                                                   // 0x92 2 ULEB128 register followed by SLEB128 offset
535             {
536                 uint32_t reg_num = m_data.GetULEB128(&offset);
537                 int64_t reg_offset = m_data.GetSLEB128(&offset);
538                 if (abi)
539                 {
540                     RegisterInfo reg_info;
541                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
542                     {
543                         if (reg_info.name)
544                         {
545                             s->Printf("[%s%+" PRIi64 "]", reg_info.name, reg_offset);
546                             break;
547                         }
548                         else if (reg_info.alt_name)
549                         {
550                             s->Printf("[%s%+" PRIi64 "]", reg_info.alt_name, reg_offset);
551                             break;
552                         }
553                     }
554                 }
555                 s->Printf("DW_OP_bregx(reg=%" PRIu32 ",offset=%" PRIi64 ")", reg_num, reg_offset);
556             }
557             break;
558         case DW_OP_piece:                                                   // 0x93 1 ULEB128 size of piece addressed
559             s->Printf("DW_OP_piece(0x%" PRIx64 ")", m_data.GetULEB128(&offset));
560             break;
561         case DW_OP_deref_size:                                              // 0x94 1 1-byte size of data retrieved
562             s->Printf("DW_OP_deref_size(0x%2.2x)", m_data.GetU8(&offset));
563             break;
564         case DW_OP_xderef_size:                                             // 0x95 1 1-byte size of data retrieved
565             s->Printf("DW_OP_xderef_size(0x%2.2x)", m_data.GetU8(&offset));
566             break;
567         case DW_OP_nop: s->PutCString("DW_OP_nop"); break;                                    // 0x96
568         case DW_OP_push_object_address: s->PutCString("DW_OP_push_object_address"); break;    // 0x97 DWARF3
569         case DW_OP_call2:                                                   // 0x98 DWARF3 1 2-byte offset of DIE
570             s->Printf("DW_OP_call2(0x%4.4x)", m_data.GetU16(&offset));
571             break;
572         case DW_OP_call4:                                                   // 0x99 DWARF3 1 4-byte offset of DIE
573             s->Printf("DW_OP_call4(0x%8.8x)", m_data.GetU32(&offset));
574             break;
575         case DW_OP_call_ref:                                                // 0x9a DWARF3 1 4- or 8-byte offset of DIE
576             s->Printf("DW_OP_call_ref(0x%8.8" PRIx64 ")", m_data.GetAddress(&offset));
577             break;
578 //      case DW_OP_form_tls_address: s << "form_tls_address"; break;        // 0x9b DWARF3
579 //      case DW_OP_call_frame_cfa: s << "call_frame_cfa"; break;            // 0x9c DWARF3
580 //      case DW_OP_bit_piece:                                               // 0x9d DWARF3 2
581 //          s->Printf("DW_OP_bit_piece(0x%x, 0x%x)", m_data.GetULEB128(&offset), m_data.GetULEB128(&offset));
582 //          break;
583 //      case DW_OP_lo_user:     s->PutCString("DW_OP_lo_user"); break;                        // 0xe0
584 //      case DW_OP_hi_user:     s->PutCString("DW_OP_hi_user"); break;                        // 0xff
585 //        case DW_OP_APPLE_extern:
586 //            s->Printf("DW_OP_APPLE_extern(%" PRIu64 ")", m_data.GetULEB128(&offset));
587 //            break;
588 //        case DW_OP_APPLE_array_ref:
589 //            s->PutCString("DW_OP_APPLE_array_ref");
590 //            break;
591         case DW_OP_APPLE_uninit:
592             s->PutCString("DW_OP_APPLE_uninit");  // 0xF0
593             break;
594 //        case DW_OP_APPLE_assign:        // 0xF1 - pops value off and assigns it to second item on stack (2nd item must have assignable context)
595 //            s->PutCString("DW_OP_APPLE_assign");
596 //            break;
597 //        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)
598 //            s->PutCString("DW_OP_APPLE_address_of");
599 //            break;
600 //        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)
601 //            s->PutCString("DW_OP_APPLE_value_of");
602 //            break;
603 //        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)
604 //            s->PutCString("DW_OP_APPLE_deref_type");
605 //            break;
606 //        case DW_OP_APPLE_expr_local:    // 0xF5 - ULEB128 expression local index
607 //            s->Printf("DW_OP_APPLE_expr_local(%" PRIu64 ")", m_data.GetULEB128(&offset));
608 //            break;
609 //        case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
610 //            {
611 //                uint8_t float_length = m_data.GetU8(&offset);
612 //                s->Printf("DW_OP_APPLE_constf(<%u> ", float_length);
613 //                m_data.Dump(s, offset, eFormatHex, float_length, 1, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
614 //                s->PutChar(')');
615 //                // Consume the float data
616 //                m_data.GetData(&offset, float_length);
617 //            }
618 //            break;
619 //        case DW_OP_APPLE_scalar_cast:
620 //            s->Printf("DW_OP_APPLE_scalar_cast(%s)", Scalar::GetValueTypeAsCString ((Scalar::Type)m_data.GetU8(&offset)));
621 //            break;
622 //        case DW_OP_APPLE_clang_cast:
623 //            {
624 //                clang::Type *clang_type = (clang::Type *)m_data.GetMaxU64(&offset, sizeof(void*));
625 //                s->Printf("DW_OP_APPLE_clang_cast(%p)", clang_type);
626 //            }
627 //            break;
628 //        case DW_OP_APPLE_clear:
629 //            s->PutCString("DW_OP_APPLE_clear");
630 //            break;
631 //        case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
632 //            s->PutCString("DW_OP_APPLE_error");
633 //            break;
634         }
635     }
636 }
637 
638 void
SetLocationListSlide(addr_t slide)639 DWARFExpression::SetLocationListSlide (addr_t slide)
640 {
641     m_loclist_slide = slide;
642 }
643 
644 int
GetRegisterKind()645 DWARFExpression::GetRegisterKind ()
646 {
647     return m_reg_kind;
648 }
649 
650 void
SetRegisterKind(RegisterKind reg_kind)651 DWARFExpression::SetRegisterKind (RegisterKind reg_kind)
652 {
653     m_reg_kind = reg_kind;
654 }
655 
656 bool
IsLocationList() const657 DWARFExpression::IsLocationList() const
658 {
659     return m_loclist_slide != LLDB_INVALID_ADDRESS;
660 }
661 
662 void
GetDescription(Stream * s,lldb::DescriptionLevel level,addr_t location_list_base_addr,ABI * abi) const663 DWARFExpression::GetDescription (Stream *s, lldb::DescriptionLevel level, addr_t location_list_base_addr, ABI *abi) const
664 {
665     if (IsLocationList())
666     {
667         // We have a location list
668         lldb::offset_t offset = 0;
669         uint32_t count = 0;
670         addr_t curr_base_addr = location_list_base_addr;
671         while (m_data.ValidOffset(offset))
672         {
673             lldb::addr_t begin_addr_offset = m_data.GetAddress(&offset);
674             lldb::addr_t end_addr_offset = m_data.GetAddress(&offset);
675             if (begin_addr_offset < end_addr_offset)
676             {
677                 if (count > 0)
678                     s->PutCString(", ");
679                 VMRange addr_range(curr_base_addr + begin_addr_offset, curr_base_addr + end_addr_offset);
680                 addr_range.Dump(s, 0, 8);
681                 s->PutChar('{');
682                 lldb::offset_t location_length = m_data.GetU16(&offset);
683                 DumpLocation (s, offset, location_length, level, abi);
684                 s->PutChar('}');
685                 offset += location_length;
686             }
687             else if (begin_addr_offset == 0 && end_addr_offset == 0)
688             {
689                 // The end of the location list is marked by both the start and end offset being zero
690                 break;
691             }
692             else
693             {
694                 if ((m_data.GetAddressByteSize() == 4 && (begin_addr_offset == UINT32_MAX)) ||
695                     (m_data.GetAddressByteSize() == 8 && (begin_addr_offset == UINT64_MAX)))
696                 {
697                     curr_base_addr = end_addr_offset + location_list_base_addr;
698                     // We have a new base address
699                     if (count > 0)
700                         s->PutCString(", ");
701                     *s << "base_addr = " << end_addr_offset;
702                 }
703             }
704 
705             count++;
706         }
707     }
708     else
709     {
710         // We have a normal location that contains DW_OP location opcodes
711         DumpLocation (s, 0, m_data.GetByteSize(), level, abi);
712     }
713 }
714 
715 static bool
ReadRegisterValueAsScalar(RegisterContext * reg_ctx,uint32_t reg_kind,uint32_t reg_num,Error * error_ptr,Value & value)716 ReadRegisterValueAsScalar
717 (
718     RegisterContext *reg_ctx,
719     uint32_t reg_kind,
720     uint32_t reg_num,
721     Error *error_ptr,
722     Value &value
723 )
724 {
725     if (reg_ctx == NULL)
726     {
727         if (error_ptr)
728             error_ptr->SetErrorStringWithFormat("No register context in frame.\n");
729     }
730     else
731     {
732         uint32_t native_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
733         if (native_reg == LLDB_INVALID_REGNUM)
734         {
735             if (error_ptr)
736                 error_ptr->SetErrorStringWithFormat("Unable to convert register kind=%u reg_num=%u to a native register number.\n", reg_kind, reg_num);
737         }
738         else
739         {
740             const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(native_reg);
741             RegisterValue reg_value;
742             if (reg_ctx->ReadRegister (reg_info, reg_value))
743             {
744                 if (reg_value.GetScalarValue(value.GetScalar()))
745                 {
746                     value.SetValueType (Value::eValueTypeScalar);
747                     value.SetContext (Value::eContextTypeRegisterInfo,
748                                       const_cast<RegisterInfo *>(reg_info));
749                     if (error_ptr)
750                         error_ptr->Clear();
751                     return true;
752                 }
753                 else
754                 {
755                     // If we get this error, then we need to implement a value
756                     // buffer in the dwarf expression evaluation function...
757                     if (error_ptr)
758                         error_ptr->SetErrorStringWithFormat ("register %s can't be converted to a scalar value",
759                                                              reg_info->name);
760                 }
761             }
762             else
763             {
764                 if (error_ptr)
765                     error_ptr->SetErrorStringWithFormat("register %s is not available", reg_info->name);
766             }
767         }
768     }
769     return false;
770 }
771 
772 //bool
773 //DWARFExpression::LocationListContainsLoadAddress (Process* process, const Address &addr) const
774 //{
775 //    return LocationListContainsLoadAddress(process, addr.GetLoadAddress(process));
776 //}
777 //
778 //bool
779 //DWARFExpression::LocationListContainsLoadAddress (Process* process, addr_t load_addr) const
780 //{
781 //    if (load_addr == LLDB_INVALID_ADDRESS)
782 //        return false;
783 //
784 //    if (IsLocationList())
785 //    {
786 //        lldb::offset_t offset = 0;
787 //
788 //        addr_t loc_list_base_addr = m_loclist_slide.GetLoadAddress(process);
789 //
790 //        if (loc_list_base_addr == LLDB_INVALID_ADDRESS)
791 //            return false;
792 //
793 //        while (m_data.ValidOffset(offset))
794 //        {
795 //            // We need to figure out what the value is for the location.
796 //            addr_t lo_pc = m_data.GetAddress(&offset);
797 //            addr_t hi_pc = m_data.GetAddress(&offset);
798 //            if (lo_pc == 0 && hi_pc == 0)
799 //                break;
800 //            else
801 //            {
802 //                lo_pc += loc_list_base_addr;
803 //                hi_pc += loc_list_base_addr;
804 //
805 //                if (lo_pc <= load_addr && load_addr < hi_pc)
806 //                    return true;
807 //
808 //                offset += m_data.GetU16(&offset);
809 //            }
810 //        }
811 //    }
812 //    return false;
813 //}
814 
815 static offset_t
GetOpcodeDataSize(const DataExtractor & data,const lldb::offset_t data_offset,const uint8_t op)816 GetOpcodeDataSize (const DataExtractor &data, const lldb::offset_t data_offset, const uint8_t op)
817 {
818     lldb::offset_t offset = data_offset;
819     switch (op)
820     {
821         case DW_OP_addr:
822         case DW_OP_call_ref:    // 0x9a 1 address sized offset of DIE (DWARF3)
823             return data.GetAddressByteSize();
824 
825         // Opcodes with no arguments
826         case DW_OP_deref:   // 0x06
827         case DW_OP_dup:     // 0x12
828         case DW_OP_drop:    // 0x13
829         case DW_OP_over:    // 0x14
830         case DW_OP_swap:    // 0x16
831         case DW_OP_rot:     // 0x17
832         case DW_OP_xderef:  // 0x18
833         case DW_OP_abs:     // 0x19
834         case DW_OP_and:     // 0x1a
835         case DW_OP_div:     // 0x1b
836         case DW_OP_minus:   // 0x1c
837         case DW_OP_mod:     // 0x1d
838         case DW_OP_mul:     // 0x1e
839         case DW_OP_neg:     // 0x1f
840         case DW_OP_not:     // 0x20
841         case DW_OP_or:      // 0x21
842         case DW_OP_plus:    // 0x22
843         case DW_OP_shl:     // 0x24
844         case DW_OP_shr:     // 0x25
845         case DW_OP_shra:    // 0x26
846         case DW_OP_xor:     // 0x27
847         case DW_OP_eq:      // 0x29
848         case DW_OP_ge:      // 0x2a
849         case DW_OP_gt:      // 0x2b
850         case DW_OP_le:      // 0x2c
851         case DW_OP_lt:      // 0x2d
852         case DW_OP_ne:      // 0x2e
853         case DW_OP_lit0:    // 0x30
854         case DW_OP_lit1:    // 0x31
855         case DW_OP_lit2:    // 0x32
856         case DW_OP_lit3:    // 0x33
857         case DW_OP_lit4:    // 0x34
858         case DW_OP_lit5:    // 0x35
859         case DW_OP_lit6:    // 0x36
860         case DW_OP_lit7:    // 0x37
861         case DW_OP_lit8:    // 0x38
862         case DW_OP_lit9:    // 0x39
863         case DW_OP_lit10:   // 0x3A
864         case DW_OP_lit11:   // 0x3B
865         case DW_OP_lit12:   // 0x3C
866         case DW_OP_lit13:   // 0x3D
867         case DW_OP_lit14:   // 0x3E
868         case DW_OP_lit15:   // 0x3F
869         case DW_OP_lit16:   // 0x40
870         case DW_OP_lit17:   // 0x41
871         case DW_OP_lit18:   // 0x42
872         case DW_OP_lit19:   // 0x43
873         case DW_OP_lit20:   // 0x44
874         case DW_OP_lit21:   // 0x45
875         case DW_OP_lit22:   // 0x46
876         case DW_OP_lit23:   // 0x47
877         case DW_OP_lit24:   // 0x48
878         case DW_OP_lit25:   // 0x49
879         case DW_OP_lit26:   // 0x4A
880         case DW_OP_lit27:   // 0x4B
881         case DW_OP_lit28:   // 0x4C
882         case DW_OP_lit29:   // 0x4D
883         case DW_OP_lit30:   // 0x4E
884         case DW_OP_lit31:   // 0x4f
885         case DW_OP_reg0:    // 0x50
886         case DW_OP_reg1:    // 0x51
887         case DW_OP_reg2:    // 0x52
888         case DW_OP_reg3:    // 0x53
889         case DW_OP_reg4:    // 0x54
890         case DW_OP_reg5:    // 0x55
891         case DW_OP_reg6:    // 0x56
892         case DW_OP_reg7:    // 0x57
893         case DW_OP_reg8:    // 0x58
894         case DW_OP_reg9:    // 0x59
895         case DW_OP_reg10:   // 0x5A
896         case DW_OP_reg11:   // 0x5B
897         case DW_OP_reg12:   // 0x5C
898         case DW_OP_reg13:   // 0x5D
899         case DW_OP_reg14:   // 0x5E
900         case DW_OP_reg15:   // 0x5F
901         case DW_OP_reg16:   // 0x60
902         case DW_OP_reg17:   // 0x61
903         case DW_OP_reg18:   // 0x62
904         case DW_OP_reg19:   // 0x63
905         case DW_OP_reg20:   // 0x64
906         case DW_OP_reg21:   // 0x65
907         case DW_OP_reg22:   // 0x66
908         case DW_OP_reg23:   // 0x67
909         case DW_OP_reg24:   // 0x68
910         case DW_OP_reg25:   // 0x69
911         case DW_OP_reg26:   // 0x6A
912         case DW_OP_reg27:   // 0x6B
913         case DW_OP_reg28:   // 0x6C
914         case DW_OP_reg29:   // 0x6D
915         case DW_OP_reg30:   // 0x6E
916         case DW_OP_reg31:   // 0x6F
917         case DW_OP_nop:     // 0x96
918         case DW_OP_push_object_address: // 0x97 DWARF3
919         case DW_OP_form_tls_address:    // 0x9b DWARF3
920         case DW_OP_call_frame_cfa:      // 0x9c DWARF3
921         case DW_OP_stack_value: // 0x9f DWARF4
922             return 0;
923 
924         // Opcodes with a single 1 byte arguments
925         case DW_OP_const1u:     // 0x08 1 1-byte constant
926         case DW_OP_const1s:     // 0x09 1 1-byte constant
927         case DW_OP_pick:        // 0x15 1 1-byte stack index
928         case DW_OP_deref_size:  // 0x94 1 1-byte size of data retrieved
929         case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
930             return 1;
931 
932         // Opcodes with a single 2 byte arguments
933         case DW_OP_const2u:     // 0x0a 1 2-byte constant
934         case DW_OP_const2s:     // 0x0b 1 2-byte constant
935         case DW_OP_skip:        // 0x2f 1 signed 2-byte constant
936         case DW_OP_bra:         // 0x28 1 signed 2-byte constant
937         case DW_OP_call2:       // 0x98 1 2-byte offset of DIE (DWARF3)
938             return 2;
939 
940         // Opcodes with a single 4 byte arguments
941         case DW_OP_const4u:     // 0x0c 1 4-byte constant
942         case DW_OP_const4s:     // 0x0d 1 4-byte constant
943         case DW_OP_call4:       // 0x99 1 4-byte offset of DIE (DWARF3)
944             return 4;
945 
946         // Opcodes with a single 8 byte arguments
947         case DW_OP_const8u:     // 0x0e 1 8-byte constant
948         case DW_OP_const8s:     // 0x0f 1 8-byte constant
949              return 8;
950 
951         // All opcodes that have a single ULEB (signed or unsigned) argument
952         case DW_OP_constu:      // 0x10 1 ULEB128 constant
953         case DW_OP_consts:      // 0x11 1 SLEB128 constant
954         case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
955         case DW_OP_breg0:       // 0x70 1 ULEB128 register
956         case DW_OP_breg1:       // 0x71 1 ULEB128 register
957         case DW_OP_breg2:       // 0x72 1 ULEB128 register
958         case DW_OP_breg3:       // 0x73 1 ULEB128 register
959         case DW_OP_breg4:       // 0x74 1 ULEB128 register
960         case DW_OP_breg5:       // 0x75 1 ULEB128 register
961         case DW_OP_breg6:       // 0x76 1 ULEB128 register
962         case DW_OP_breg7:       // 0x77 1 ULEB128 register
963         case DW_OP_breg8:       // 0x78 1 ULEB128 register
964         case DW_OP_breg9:       // 0x79 1 ULEB128 register
965         case DW_OP_breg10:      // 0x7a 1 ULEB128 register
966         case DW_OP_breg11:      // 0x7b 1 ULEB128 register
967         case DW_OP_breg12:      // 0x7c 1 ULEB128 register
968         case DW_OP_breg13:      // 0x7d 1 ULEB128 register
969         case DW_OP_breg14:      // 0x7e 1 ULEB128 register
970         case DW_OP_breg15:      // 0x7f 1 ULEB128 register
971         case DW_OP_breg16:      // 0x80 1 ULEB128 register
972         case DW_OP_breg17:      // 0x81 1 ULEB128 register
973         case DW_OP_breg18:      // 0x82 1 ULEB128 register
974         case DW_OP_breg19:      // 0x83 1 ULEB128 register
975         case DW_OP_breg20:      // 0x84 1 ULEB128 register
976         case DW_OP_breg21:      // 0x85 1 ULEB128 register
977         case DW_OP_breg22:      // 0x86 1 ULEB128 register
978         case DW_OP_breg23:      // 0x87 1 ULEB128 register
979         case DW_OP_breg24:      // 0x88 1 ULEB128 register
980         case DW_OP_breg25:      // 0x89 1 ULEB128 register
981         case DW_OP_breg26:      // 0x8a 1 ULEB128 register
982         case DW_OP_breg27:      // 0x8b 1 ULEB128 register
983         case DW_OP_breg28:      // 0x8c 1 ULEB128 register
984         case DW_OP_breg29:      // 0x8d 1 ULEB128 register
985         case DW_OP_breg30:      // 0x8e 1 ULEB128 register
986         case DW_OP_breg31:      // 0x8f 1 ULEB128 register
987         case DW_OP_regx:        // 0x90 1 ULEB128 register
988         case DW_OP_fbreg:       // 0x91 1 SLEB128 offset
989         case DW_OP_piece:       // 0x93 1 ULEB128 size of piece addressed
990             data.Skip_LEB128(&offset);
991             return offset - data_offset;
992 
993             // All opcodes that have a 2 ULEB (signed or unsigned) arguments
994         case DW_OP_bregx:       // 0x92 2 ULEB128 register followed by SLEB128 offset
995         case DW_OP_bit_piece:   // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
996             data.Skip_LEB128(&offset);
997             data.Skip_LEB128(&offset);
998             return offset - data_offset;
999 
1000         case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size (DWARF4)
1001             {
1002                 uint64_t block_len = data.Skip_LEB128(&offset);
1003                 offset += block_len;
1004                 return offset - data_offset;
1005             }
1006 
1007         default:
1008             break;
1009     }
1010     return LLDB_INVALID_OFFSET;
1011 }
1012 
1013 lldb::addr_t
GetLocation_DW_OP_addr(uint32_t op_addr_idx,bool & error) const1014 DWARFExpression::GetLocation_DW_OP_addr (uint32_t op_addr_idx, bool &error) const
1015 {
1016     error = false;
1017     if (IsLocationList())
1018         return LLDB_INVALID_ADDRESS;
1019     lldb::offset_t offset = 0;
1020     uint32_t curr_op_addr_idx = 0;
1021     while (m_data.ValidOffset(offset))
1022     {
1023         const uint8_t op = m_data.GetU8(&offset);
1024 
1025         if (op == DW_OP_addr)
1026         {
1027             const lldb::addr_t op_file_addr = m_data.GetAddress(&offset);
1028             if (curr_op_addr_idx == op_addr_idx)
1029                 return op_file_addr;
1030             else
1031                 ++curr_op_addr_idx;
1032         }
1033         else
1034         {
1035             const offset_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1036             if (op_arg_size == LLDB_INVALID_OFFSET)
1037             {
1038                 error = true;
1039                 break;
1040             }
1041             offset += op_arg_size;
1042         }
1043     }
1044     return LLDB_INVALID_ADDRESS;
1045 }
1046 
1047 bool
Update_DW_OP_addr(lldb::addr_t file_addr)1048 DWARFExpression::Update_DW_OP_addr (lldb::addr_t file_addr)
1049 {
1050     if (IsLocationList())
1051         return false;
1052     lldb::offset_t offset = 0;
1053     while (m_data.ValidOffset(offset))
1054     {
1055         const uint8_t op = m_data.GetU8(&offset);
1056 
1057         if (op == DW_OP_addr)
1058         {
1059             const uint32_t addr_byte_size = m_data.GetAddressByteSize();
1060             // We have to make a copy of the data as we don't know if this
1061             // data is from a read only memory mapped buffer, so we duplicate
1062             // all of the data first, then modify it, and if all goes well,
1063             // we then replace the data for this expression
1064 
1065             // So first we copy the data into a heap buffer
1066             std::unique_ptr<DataBufferHeap> head_data_ap (new DataBufferHeap (m_data.GetDataStart(),
1067                                                                              m_data.GetByteSize()));
1068 
1069             // Make en encoder so we can write the address into the buffer using
1070             // the correct byte order (endianness)
1071             DataEncoder encoder (head_data_ap->GetBytes(),
1072                                  head_data_ap->GetByteSize(),
1073                                  m_data.GetByteOrder(),
1074                                  addr_byte_size);
1075 
1076             // Replace the address in the new buffer
1077             if (encoder.PutMaxU64 (offset, addr_byte_size, file_addr) == UINT32_MAX)
1078                 return false;
1079 
1080             // All went well, so now we can reset the data using a shared
1081             // pointer to the heap data so "m_data" will now correctly
1082             // manage the heap data.
1083             m_data.SetData (DataBufferSP (head_data_ap.release()));
1084             return true;
1085         }
1086         else
1087         {
1088             const offset_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
1089             if (op_arg_size == LLDB_INVALID_OFFSET)
1090                 break;
1091             offset += op_arg_size;
1092         }
1093     }
1094     return false;
1095 }
1096 
1097 bool
LocationListContainsAddress(lldb::addr_t loclist_base_addr,lldb::addr_t addr) const1098 DWARFExpression::LocationListContainsAddress (lldb::addr_t loclist_base_addr, lldb::addr_t addr) const
1099 {
1100     if (addr == LLDB_INVALID_ADDRESS)
1101         return false;
1102 
1103     if (IsLocationList())
1104     {
1105         lldb::offset_t offset = 0;
1106 
1107         if (loclist_base_addr == LLDB_INVALID_ADDRESS)
1108             return false;
1109 
1110         while (m_data.ValidOffset(offset))
1111         {
1112             // We need to figure out what the value is for the location.
1113             addr_t lo_pc = m_data.GetAddress(&offset);
1114             addr_t hi_pc = m_data.GetAddress(&offset);
1115             if (lo_pc == 0 && hi_pc == 0)
1116                 break;
1117             else
1118             {
1119                 lo_pc += loclist_base_addr - m_loclist_slide;
1120                 hi_pc += loclist_base_addr - m_loclist_slide;
1121 
1122                 if (lo_pc <= addr && addr < hi_pc)
1123                     return true;
1124 
1125                 offset += m_data.GetU16(&offset);
1126             }
1127         }
1128     }
1129     return false;
1130 }
1131 
1132 bool
GetLocation(addr_t base_addr,addr_t pc,lldb::offset_t & offset,lldb::offset_t & length)1133 DWARFExpression::GetLocation (addr_t base_addr, addr_t pc, lldb::offset_t &offset, lldb::offset_t &length)
1134 {
1135     offset = 0;
1136     if (!IsLocationList())
1137     {
1138         length = m_data.GetByteSize();
1139         return true;
1140     }
1141 
1142     if (base_addr != LLDB_INVALID_ADDRESS && pc != LLDB_INVALID_ADDRESS)
1143     {
1144         addr_t curr_base_addr = base_addr;
1145 
1146         while (m_data.ValidOffset(offset))
1147         {
1148             // We need to figure out what the value is for the location.
1149             addr_t lo_pc = m_data.GetAddress(&offset);
1150             addr_t hi_pc = m_data.GetAddress(&offset);
1151             if (lo_pc == 0 && hi_pc == 0)
1152             {
1153                 break;
1154             }
1155             else
1156             {
1157                 lo_pc += curr_base_addr - m_loclist_slide;
1158                 hi_pc += curr_base_addr - m_loclist_slide;
1159 
1160                 length = m_data.GetU16(&offset);
1161 
1162                 if (length > 0 && lo_pc <= pc && pc < hi_pc)
1163                     return true;
1164 
1165                 offset += length;
1166             }
1167         }
1168     }
1169     offset = LLDB_INVALID_OFFSET;
1170     length = 0;
1171     return false;
1172 }
1173 
1174 bool
DumpLocationForAddress(Stream * s,lldb::DescriptionLevel level,addr_t base_addr,addr_t address,ABI * abi)1175 DWARFExpression::DumpLocationForAddress (Stream *s,
1176                                          lldb::DescriptionLevel level,
1177                                          addr_t base_addr,
1178                                          addr_t address,
1179                                          ABI *abi)
1180 {
1181     lldb::offset_t offset = 0;
1182     lldb::offset_t length = 0;
1183 
1184     if (GetLocation (base_addr, address, offset, length))
1185     {
1186         if (length > 0)
1187         {
1188             DumpLocation(s, offset, length, level, abi);
1189             return true;
1190         }
1191     }
1192     return false;
1193 }
1194 
1195 bool
Evaluate(ExecutionContextScope * exe_scope,ClangExpressionVariableList * expr_locals,ClangExpressionDeclMap * decl_map,lldb::addr_t loclist_base_load_addr,const Value * initial_value_ptr,Value & result,Error * error_ptr) const1196 DWARFExpression::Evaluate
1197 (
1198     ExecutionContextScope *exe_scope,
1199     ClangExpressionVariableList *expr_locals,
1200     ClangExpressionDeclMap *decl_map,
1201     lldb::addr_t loclist_base_load_addr,
1202     const Value* initial_value_ptr,
1203     Value& result,
1204     Error *error_ptr
1205 ) const
1206 {
1207     ExecutionContext exe_ctx (exe_scope);
1208     return Evaluate(&exe_ctx, expr_locals, decl_map, NULL, loclist_base_load_addr, initial_value_ptr, result, error_ptr);
1209 }
1210 
1211 bool
Evaluate(ExecutionContext * exe_ctx,ClangExpressionVariableList * expr_locals,ClangExpressionDeclMap * decl_map,RegisterContext * reg_ctx,lldb::addr_t loclist_base_load_addr,const Value * initial_value_ptr,Value & result,Error * error_ptr) const1212 DWARFExpression::Evaluate
1213 (
1214     ExecutionContext *exe_ctx,
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         lldb::offset_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, 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, 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
Evaluate(ExecutionContext * exe_ctx,ClangExpressionVariableList * expr_locals,ClangExpressionDeclMap * decl_map,RegisterContext * reg_ctx,const DataExtractor & opcodes,const lldb::offset_t opcodes_offset,const lldb::offset_t opcodes_length,const uint32_t reg_kind,const Value * initial_value_ptr,Value & result,Error * error_ptr)1289 DWARFExpression::Evaluate
1290 (
1291     ExecutionContext *exe_ctx,
1292     ClangExpressionVariableList *expr_locals,
1293     ClangExpressionDeclMap *decl_map,
1294     RegisterContext *reg_ctx,
1295     const DataExtractor& opcodes,
1296     const lldb::offset_t opcodes_offset,
1297     const lldb::offset_t opcodes_length,
1298     const uint32_t reg_kind,
1299     const Value* initial_value_ptr,
1300     Value& result,
1301     Error *error_ptr
1302 )
1303 {
1304 
1305     if (opcodes_length == 0)
1306     {
1307         if (error_ptr)
1308             error_ptr->SetErrorString ("no location, value may have been optimized out");
1309         return false;
1310     }
1311     std::vector<Value> stack;
1312 
1313     Process *process = NULL;
1314     StackFrame *frame = NULL;
1315 
1316     if (exe_ctx)
1317     {
1318         process = exe_ctx->GetProcessPtr();
1319         frame = exe_ctx->GetFramePtr();
1320     }
1321     if (reg_ctx == NULL && frame)
1322         reg_ctx = frame->GetRegisterContext().get();
1323 
1324     if (initial_value_ptr)
1325         stack.push_back(*initial_value_ptr);
1326 
1327     lldb::offset_t offset = opcodes_offset;
1328     const lldb::offset_t end_offset = opcodes_offset + opcodes_length;
1329     Value tmp;
1330     uint32_t reg_num;
1331 
1332     // Make sure all of the data is available in opcodes.
1333     if (!opcodes.ValidOffsetForDataOfSize(opcodes_offset, opcodes_length))
1334     {
1335         if (error_ptr)
1336             error_ptr->SetErrorString ("invalid offset and/or length for opcodes buffer.");
1337         return false;
1338     }
1339     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1340 
1341 
1342     while (opcodes.ValidOffset(offset) && offset < end_offset)
1343     {
1344         const lldb::offset_t op_offset = offset;
1345         const uint8_t op = opcodes.GetU8(&offset);
1346 
1347         if (log && log->GetVerbose())
1348         {
1349             size_t count = stack.size();
1350             log->Printf("Stack before operation has %lu values:", count);
1351             for (size_t i=0; i<count; ++i)
1352             {
1353                 StreamString new_value;
1354                 new_value.Printf("[%" PRIu64 "]", (uint64_t)i);
1355                 stack[i].Dump(&new_value);
1356                 log->Printf("  %s", new_value.GetData());
1357             }
1358             log->Printf("0x%8.8" PRIx64 ": %s", op_offset, DW_OP_value_to_name(op));
1359         }
1360         switch (op)
1361         {
1362         //----------------------------------------------------------------------
1363         // The DW_OP_addr operation has a single operand that encodes a machine
1364         // address and whose size is the size of an address on the target machine.
1365         //----------------------------------------------------------------------
1366         case DW_OP_addr:
1367             stack.push_back(Scalar(opcodes.GetAddress(&offset)));
1368             stack.back().SetValueType (Value::eValueTypeFileAddress);
1369             break;
1370 
1371         //----------------------------------------------------------------------
1372         // The DW_OP_addr_sect_offset4 is used for any location expressions in
1373         // shared libraries that have a location like:
1374         //  DW_OP_addr(0x1000)
1375         // If this address resides in a shared library, then this virtual
1376         // address won't make sense when it is evaluated in the context of a
1377         // running process where shared libraries have been slid. To account for
1378         // this, this new address type where we can store the section pointer
1379         // and a 4 byte offset.
1380         //----------------------------------------------------------------------
1381 //      case DW_OP_addr_sect_offset4:
1382 //          {
1383 //              result_type = eResultTypeFileAddress;
1384 //              lldb::Section *sect = (lldb::Section *)opcodes.GetMaxU64(&offset, sizeof(void *));
1385 //              lldb::addr_t sect_offset = opcodes.GetU32(&offset);
1386 //
1387 //              Address so_addr (sect, sect_offset);
1388 //              lldb::addr_t load_addr = so_addr.GetLoadAddress();
1389 //              if (load_addr != LLDB_INVALID_ADDRESS)
1390 //              {
1391 //                  // We successfully resolve a file address to a load
1392 //                  // address.
1393 //                  stack.push_back(load_addr);
1394 //                  break;
1395 //              }
1396 //              else
1397 //              {
1398 //                  // We were able
1399 //                  if (error_ptr)
1400 //                      error_ptr->SetErrorStringWithFormat ("Section %s in %s is not currently loaded.\n", sect->GetName().AsCString(), sect->GetModule()->GetFileSpec().GetFilename().AsCString());
1401 //                  return false;
1402 //              }
1403 //          }
1404 //          break;
1405 
1406         //----------------------------------------------------------------------
1407         // OPCODE: DW_OP_deref
1408         // OPERANDS: none
1409         // DESCRIPTION: Pops the top stack entry and treats it as an address.
1410         // The value retrieved from that address is pushed. The size of the
1411         // data retrieved from the dereferenced address is the size of an
1412         // address on the target machine.
1413         //----------------------------------------------------------------------
1414         case DW_OP_deref:
1415             {
1416                 Value::ValueType value_type = stack.back().GetValueType();
1417                 switch (value_type)
1418                 {
1419                 case Value::eValueTypeHostAddress:
1420                     {
1421                         void *src = (void *)stack.back().GetScalar().ULongLong();
1422                         intptr_t ptr;
1423                         ::memcpy (&ptr, src, sizeof(void *));
1424                         stack.back().GetScalar() = ptr;
1425                         stack.back().ClearContext();
1426                     }
1427                     break;
1428                 case Value::eValueTypeLoadAddress:
1429                     if (exe_ctx)
1430                     {
1431                         if (process)
1432                         {
1433                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1434                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1435                             uint32_t addr_size = process->GetAddressByteSize();
1436                             Error error;
1437                             if (process->ReadMemory(pointer_addr, &addr_bytes, addr_size, error) == addr_size)
1438                             {
1439                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), addr_size);
1440                                 lldb::offset_t addr_data_offset = 0;
1441                                 stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1442                                 stack.back().ClearContext();
1443                             }
1444                             else
1445                             {
1446                                 if (error_ptr)
1447                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%" PRIx64 " for DW_OP_deref: %s\n",
1448                                                                          pointer_addr,
1449                                                                          error.AsCString());
1450                                 return false;
1451                             }
1452                         }
1453                         else
1454                         {
1455                             if (error_ptr)
1456                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1457                             return false;
1458                         }
1459                     }
1460                     else
1461                     {
1462                         if (error_ptr)
1463                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1464                         return false;
1465                     }
1466                     break;
1467 
1468                 default:
1469                     break;
1470                 }
1471 
1472             }
1473             break;
1474 
1475         //----------------------------------------------------------------------
1476         // OPCODE: DW_OP_deref_size
1477         // OPERANDS: 1
1478         //  1 - uint8_t that specifies the size of the data to dereference.
1479         // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
1480         // stack entry and treats it as an address. The value retrieved from that
1481         // address is pushed. In the DW_OP_deref_size operation, however, the
1482         // size in bytes of the data retrieved from the dereferenced address is
1483         // specified by the single operand. This operand is a 1-byte unsigned
1484         // integral constant whose value may not be larger than the size of an
1485         // address on the target machine. The data retrieved is zero extended
1486         // to the size of an address on the target machine before being pushed
1487         // on the expression stack.
1488         //----------------------------------------------------------------------
1489         case DW_OP_deref_size:
1490             {
1491                 uint8_t size = opcodes.GetU8(&offset);
1492                 Value::ValueType value_type = stack.back().GetValueType();
1493                 switch (value_type)
1494                 {
1495                 case Value::eValueTypeHostAddress:
1496                     {
1497                         void *src = (void *)stack.back().GetScalar().ULongLong();
1498                         intptr_t ptr;
1499                         ::memcpy (&ptr, src, sizeof(void *));
1500                         // I can't decide whether the size operand should apply to the bytes in their
1501                         // lldb-host endianness or the target endianness.. I doubt this'll ever come up
1502                         // but I'll opt for assuming big endian regardless.
1503                         switch (size)
1504                         {
1505                             case 1: ptr = ptr & 0xff; break;
1506                             case 2: ptr = ptr & 0xffff; break;
1507                             case 3: ptr = ptr & 0xffffff; break;
1508                             case 4: ptr = ptr & 0xffffffff; break;
1509                             // the casts are added to work around the case where intptr_t is a 32 bit quantity;
1510                             // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this program.
1511                             case 5: ptr = (intptr_t) ptr & 0xffffffffffULL; break;
1512                             case 6: ptr = (intptr_t) ptr & 0xffffffffffffULL; break;
1513                             case 7: ptr = (intptr_t) ptr & 0xffffffffffffffULL; break;
1514                             default: break;
1515                         }
1516                         stack.back().GetScalar() = ptr;
1517                         stack.back().ClearContext();
1518                     }
1519                     break;
1520                 case Value::eValueTypeLoadAddress:
1521                     if (exe_ctx)
1522                     {
1523                         if (process)
1524                         {
1525                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
1526                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
1527                             Error error;
1528                             if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) == size)
1529                             {
1530                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), size);
1531                                 lldb::offset_t addr_data_offset = 0;
1532                                 switch (size)
1533                                 {
1534                                     case 1: stack.back().GetScalar() = addr_data.GetU8(&addr_data_offset); break;
1535                                     case 2: stack.back().GetScalar() = addr_data.GetU16(&addr_data_offset); break;
1536                                     case 4: stack.back().GetScalar() = addr_data.GetU32(&addr_data_offset); break;
1537                                     case 8: stack.back().GetScalar() = addr_data.GetU64(&addr_data_offset); break;
1538                                     default: stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
1539                                 }
1540                                 stack.back().ClearContext();
1541                             }
1542                             else
1543                             {
1544                                 if (error_ptr)
1545                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%" PRIx64 " for DW_OP_deref: %s\n",
1546                                                                          pointer_addr,
1547                                                                          error.AsCString());
1548                                 return false;
1549                             }
1550                         }
1551                         else
1552                         {
1553                             if (error_ptr)
1554                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
1555                             return false;
1556                         }
1557                     }
1558                     else
1559                     {
1560                         if (error_ptr)
1561                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
1562                         return false;
1563                     }
1564                     break;
1565 
1566                 default:
1567                     break;
1568                 }
1569 
1570             }
1571             break;
1572 
1573         //----------------------------------------------------------------------
1574         // OPCODE: DW_OP_xderef_size
1575         // OPERANDS: 1
1576         //  1 - uint8_t that specifies the size of the data to dereference.
1577         // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
1578         // the top of the stack is treated as an address. The second stack
1579         // entry is treated as an "address space identifier" for those
1580         // architectures that support multiple address spaces. The top two
1581         // stack elements are popped, a data item is retrieved through an
1582         // implementation-defined address calculation and pushed as the new
1583         // stack top. In the DW_OP_xderef_size operation, however, the size in
1584         // bytes of the data retrieved from the dereferenced address is
1585         // specified by the single operand. This operand is a 1-byte unsigned
1586         // integral constant whose value may not be larger than the size of an
1587         // address on the target machine. The data retrieved is zero extended
1588         // to the size of an address on the target machine before being pushed
1589         // on the expression stack.
1590         //----------------------------------------------------------------------
1591         case DW_OP_xderef_size:
1592             if (error_ptr)
1593                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
1594             return false;
1595         //----------------------------------------------------------------------
1596         // OPCODE: DW_OP_xderef
1597         // OPERANDS: none
1598         // DESCRIPTION: Provides an extended dereference mechanism. The entry at
1599         // the top of the stack is treated as an address. The second stack entry
1600         // is treated as an "address space identifier" for those architectures
1601         // that support multiple address spaces. The top two stack elements are
1602         // popped, a data item is retrieved through an implementation-defined
1603         // address calculation and pushed as the new stack top. The size of the
1604         // data retrieved from the dereferenced address is the size of an address
1605         // on the target machine.
1606         //----------------------------------------------------------------------
1607         case DW_OP_xderef:
1608             if (error_ptr)
1609                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
1610             return false;
1611 
1612         //----------------------------------------------------------------------
1613         // All DW_OP_constXXX opcodes have a single operand as noted below:
1614         //
1615         // Opcode           Operand 1
1616         // ---------------  ----------------------------------------------------
1617         // DW_OP_const1u    1-byte unsigned integer constant
1618         // DW_OP_const1s    1-byte signed integer constant
1619         // DW_OP_const2u    2-byte unsigned integer constant
1620         // DW_OP_const2s    2-byte signed integer constant
1621         // DW_OP_const4u    4-byte unsigned integer constant
1622         // DW_OP_const4s    4-byte signed integer constant
1623         // DW_OP_const8u    8-byte unsigned integer constant
1624         // DW_OP_const8s    8-byte signed integer constant
1625         // DW_OP_constu     unsigned LEB128 integer constant
1626         // DW_OP_consts     signed LEB128 integer constant
1627         //----------------------------------------------------------------------
1628         case DW_OP_const1u             :    stack.push_back(Scalar(( uint8_t)opcodes.GetU8 (&offset))); break;
1629         case DW_OP_const1s             :    stack.push_back(Scalar((  int8_t)opcodes.GetU8 (&offset))); break;
1630         case DW_OP_const2u             :    stack.push_back(Scalar((uint16_t)opcodes.GetU16 (&offset))); break;
1631         case DW_OP_const2s             :    stack.push_back(Scalar(( int16_t)opcodes.GetU16 (&offset))); break;
1632         case DW_OP_const4u             :    stack.push_back(Scalar((uint32_t)opcodes.GetU32 (&offset))); break;
1633         case DW_OP_const4s             :    stack.push_back(Scalar(( int32_t)opcodes.GetU32 (&offset))); break;
1634         case DW_OP_const8u             :    stack.push_back(Scalar((uint64_t)opcodes.GetU64 (&offset))); break;
1635         case DW_OP_const8s             :    stack.push_back(Scalar(( int64_t)opcodes.GetU64 (&offset))); break;
1636         case DW_OP_constu              :    stack.push_back(Scalar(opcodes.GetULEB128 (&offset))); break;
1637         case DW_OP_consts              :    stack.push_back(Scalar(opcodes.GetSLEB128 (&offset))); break;
1638 
1639         //----------------------------------------------------------------------
1640         // OPCODE: DW_OP_dup
1641         // OPERANDS: none
1642         // DESCRIPTION: duplicates the value at the top of the stack
1643         //----------------------------------------------------------------------
1644         case DW_OP_dup:
1645             if (stack.empty())
1646             {
1647                 if (error_ptr)
1648                     error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
1649                 return false;
1650             }
1651             else
1652                 stack.push_back(stack.back());
1653             break;
1654 
1655         //----------------------------------------------------------------------
1656         // OPCODE: DW_OP_drop
1657         // OPERANDS: none
1658         // DESCRIPTION: pops the value at the top of the stack
1659         //----------------------------------------------------------------------
1660         case DW_OP_drop:
1661             if (stack.empty())
1662             {
1663                 if (error_ptr)
1664                     error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
1665                 return false;
1666             }
1667             else
1668                 stack.pop_back();
1669             break;
1670 
1671         //----------------------------------------------------------------------
1672         // OPCODE: DW_OP_over
1673         // OPERANDS: none
1674         // DESCRIPTION: Duplicates the entry currently second in the stack at
1675         // the top of the stack.
1676         //----------------------------------------------------------------------
1677         case DW_OP_over:
1678             if (stack.size() < 2)
1679             {
1680                 if (error_ptr)
1681                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_over.");
1682                 return false;
1683             }
1684             else
1685                 stack.push_back(stack[stack.size() - 2]);
1686             break;
1687 
1688 
1689         //----------------------------------------------------------------------
1690         // OPCODE: DW_OP_pick
1691         // OPERANDS: uint8_t index into the current stack
1692         // DESCRIPTION: The stack entry with the specified index (0 through 255,
1693         // inclusive) is pushed on the stack
1694         //----------------------------------------------------------------------
1695         case DW_OP_pick:
1696             {
1697                 uint8_t pick_idx = opcodes.GetU8(&offset);
1698                 if (pick_idx < stack.size())
1699                     stack.push_back(stack[pick_idx]);
1700                 else
1701                 {
1702                     if (error_ptr)
1703                         error_ptr->SetErrorStringWithFormat("Index %u out of range for DW_OP_pick.\n", pick_idx);
1704                     return false;
1705                 }
1706             }
1707             break;
1708 
1709         //----------------------------------------------------------------------
1710         // OPCODE: DW_OP_swap
1711         // OPERANDS: none
1712         // DESCRIPTION: swaps the top two stack entries. The entry at the top
1713         // of the stack becomes the second stack entry, and the second entry
1714         // becomes the top of the stack
1715         //----------------------------------------------------------------------
1716         case DW_OP_swap:
1717             if (stack.size() < 2)
1718             {
1719                 if (error_ptr)
1720                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_swap.");
1721                 return false;
1722             }
1723             else
1724             {
1725                 tmp = stack.back();
1726                 stack.back() = stack[stack.size() - 2];
1727                 stack[stack.size() - 2] = tmp;
1728             }
1729             break;
1730 
1731         //----------------------------------------------------------------------
1732         // OPCODE: DW_OP_rot
1733         // OPERANDS: none
1734         // DESCRIPTION: Rotates the first three stack entries. The entry at
1735         // the top of the stack becomes the third stack entry, the second
1736         // entry becomes the top of the stack, and the third entry becomes
1737         // the second entry.
1738         //----------------------------------------------------------------------
1739         case DW_OP_rot:
1740             if (stack.size() < 3)
1741             {
1742                 if (error_ptr)
1743                     error_ptr->SetErrorString("Expression stack needs at least 3 items for DW_OP_rot.");
1744                 return false;
1745             }
1746             else
1747             {
1748                 size_t last_idx = stack.size() - 1;
1749                 Value old_top = stack[last_idx];
1750                 stack[last_idx] = stack[last_idx - 1];
1751                 stack[last_idx - 1] = stack[last_idx - 2];
1752                 stack[last_idx - 2] = old_top;
1753             }
1754             break;
1755 
1756         //----------------------------------------------------------------------
1757         // OPCODE: DW_OP_abs
1758         // OPERANDS: none
1759         // DESCRIPTION: pops the top stack entry, interprets it as a signed
1760         // value and pushes its absolute value. If the absolute value can not be
1761         // represented, the result is undefined.
1762         //----------------------------------------------------------------------
1763         case DW_OP_abs:
1764             if (stack.empty())
1765             {
1766                 if (error_ptr)
1767                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_abs.");
1768                 return false;
1769             }
1770             else if (stack.back().ResolveValue(exe_ctx).AbsoluteValue() == false)
1771             {
1772                 if (error_ptr)
1773                     error_ptr->SetErrorString("Failed to take the absolute value of the first stack item.");
1774                 return false;
1775             }
1776             break;
1777 
1778         //----------------------------------------------------------------------
1779         // OPCODE: DW_OP_and
1780         // OPERANDS: none
1781         // DESCRIPTION: pops the top two stack values, performs a bitwise and
1782         // operation on the two, and pushes the result.
1783         //----------------------------------------------------------------------
1784         case DW_OP_and:
1785             if (stack.size() < 2)
1786             {
1787                 if (error_ptr)
1788                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_and.");
1789                 return false;
1790             }
1791             else
1792             {
1793                 tmp = stack.back();
1794                 stack.pop_back();
1795                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx);
1796             }
1797             break;
1798 
1799         //----------------------------------------------------------------------
1800         // OPCODE: DW_OP_div
1801         // OPERANDS: none
1802         // DESCRIPTION: pops the top two stack values, divides the former second
1803         // entry by the former top of the stack using signed division, and
1804         // pushes the result.
1805         //----------------------------------------------------------------------
1806         case DW_OP_div:
1807             if (stack.size() < 2)
1808             {
1809                 if (error_ptr)
1810                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_div.");
1811                 return false;
1812             }
1813             else
1814             {
1815                 tmp = stack.back();
1816                 if (tmp.ResolveValue(exe_ctx).IsZero())
1817                 {
1818                     if (error_ptr)
1819                         error_ptr->SetErrorString("Divide by zero.");
1820                     return false;
1821                 }
1822                 else
1823                 {
1824                     stack.pop_back();
1825                     stack.back() = stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx);
1826                     if (!stack.back().ResolveValue(exe_ctx).IsValid())
1827                     {
1828                         if (error_ptr)
1829                             error_ptr->SetErrorString("Divide failed.");
1830                         return false;
1831                     }
1832                 }
1833             }
1834             break;
1835 
1836         //----------------------------------------------------------------------
1837         // OPCODE: DW_OP_minus
1838         // OPERANDS: none
1839         // DESCRIPTION: pops the top two stack values, subtracts the former top
1840         // of the stack from the former second entry, and pushes the result.
1841         //----------------------------------------------------------------------
1842         case DW_OP_minus:
1843             if (stack.size() < 2)
1844             {
1845                 if (error_ptr)
1846                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_minus.");
1847                 return false;
1848             }
1849             else
1850             {
1851                 tmp = stack.back();
1852                 stack.pop_back();
1853                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx);
1854             }
1855             break;
1856 
1857         //----------------------------------------------------------------------
1858         // OPCODE: DW_OP_mod
1859         // OPERANDS: none
1860         // DESCRIPTION: pops the top two stack values and pushes the result of
1861         // the calculation: former second stack entry modulo the former top of
1862         // the stack.
1863         //----------------------------------------------------------------------
1864         case DW_OP_mod:
1865             if (stack.size() < 2)
1866             {
1867                 if (error_ptr)
1868                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mod.");
1869                 return false;
1870             }
1871             else
1872             {
1873                 tmp = stack.back();
1874                 stack.pop_back();
1875                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx);
1876             }
1877             break;
1878 
1879 
1880         //----------------------------------------------------------------------
1881         // OPCODE: DW_OP_mul
1882         // OPERANDS: none
1883         // DESCRIPTION: pops the top two stack entries, multiplies them
1884         // together, and pushes the result.
1885         //----------------------------------------------------------------------
1886         case DW_OP_mul:
1887             if (stack.size() < 2)
1888             {
1889                 if (error_ptr)
1890                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mul.");
1891                 return false;
1892             }
1893             else
1894             {
1895                 tmp = stack.back();
1896                 stack.pop_back();
1897                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) * tmp.ResolveValue(exe_ctx);
1898             }
1899             break;
1900 
1901         //----------------------------------------------------------------------
1902         // OPCODE: DW_OP_neg
1903         // OPERANDS: none
1904         // DESCRIPTION: pops the top stack entry, and pushes its negation.
1905         //----------------------------------------------------------------------
1906         case DW_OP_neg:
1907             if (stack.empty())
1908             {
1909                 if (error_ptr)
1910                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_neg.");
1911                 return false;
1912             }
1913             else
1914             {
1915                 if (stack.back().ResolveValue(exe_ctx).UnaryNegate() == false)
1916                 {
1917                     if (error_ptr)
1918                         error_ptr->SetErrorString("Unary negate failed.");
1919                     return false;
1920                 }
1921             }
1922             break;
1923 
1924         //----------------------------------------------------------------------
1925         // OPCODE: DW_OP_not
1926         // OPERANDS: none
1927         // DESCRIPTION: pops the top stack entry, and pushes its bitwise
1928         // complement
1929         //----------------------------------------------------------------------
1930         case DW_OP_not:
1931             if (stack.empty())
1932             {
1933                 if (error_ptr)
1934                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_not.");
1935                 return false;
1936             }
1937             else
1938             {
1939                 if (stack.back().ResolveValue(exe_ctx).OnesComplement() == false)
1940                 {
1941                     if (error_ptr)
1942                         error_ptr->SetErrorString("Logical NOT failed.");
1943                     return false;
1944                 }
1945             }
1946             break;
1947 
1948         //----------------------------------------------------------------------
1949         // OPCODE: DW_OP_or
1950         // OPERANDS: none
1951         // DESCRIPTION: pops the top two stack entries, performs a bitwise or
1952         // operation on the two, and pushes the result.
1953         //----------------------------------------------------------------------
1954         case DW_OP_or:
1955             if (stack.size() < 2)
1956             {
1957                 if (error_ptr)
1958                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_or.");
1959                 return false;
1960             }
1961             else
1962             {
1963                 tmp = stack.back();
1964                 stack.pop_back();
1965                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx);
1966             }
1967             break;
1968 
1969         //----------------------------------------------------------------------
1970         // OPCODE: DW_OP_plus
1971         // OPERANDS: none
1972         // DESCRIPTION: pops the top two stack entries, adds them together, and
1973         // pushes the result.
1974         //----------------------------------------------------------------------
1975         case DW_OP_plus:
1976             if (stack.size() < 2)
1977             {
1978                 if (error_ptr)
1979                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_plus.");
1980                 return false;
1981             }
1982             else
1983             {
1984                 tmp = stack.back();
1985                 stack.pop_back();
1986                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) + tmp.ResolveValue(exe_ctx);
1987             }
1988             break;
1989 
1990         //----------------------------------------------------------------------
1991         // OPCODE: DW_OP_plus_uconst
1992         // OPERANDS: none
1993         // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
1994         // constant operand and pushes the result.
1995         //----------------------------------------------------------------------
1996         case DW_OP_plus_uconst:
1997             if (stack.empty())
1998             {
1999                 if (error_ptr)
2000                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_plus_uconst.");
2001                 return false;
2002             }
2003             else
2004             {
2005                 const uint64_t uconst_value = opcodes.GetULEB128(&offset);
2006                 // Implicit conversion from a UINT to a Scalar...
2007                 stack.back().ResolveValue(exe_ctx) += uconst_value;
2008                 if (!stack.back().ResolveValue(exe_ctx).IsValid())
2009                 {
2010                     if (error_ptr)
2011                         error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
2012                     return false;
2013                 }
2014             }
2015             break;
2016 
2017         //----------------------------------------------------------------------
2018         // OPCODE: DW_OP_shl
2019         // OPERANDS: none
2020         // DESCRIPTION:  pops the top two stack entries, shifts the former
2021         // second entry left by the number of bits specified by the former top
2022         // of the stack, and pushes the result.
2023         //----------------------------------------------------------------------
2024         case DW_OP_shl:
2025             if (stack.size() < 2)
2026             {
2027                 if (error_ptr)
2028                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shl.");
2029                 return false;
2030             }
2031             else
2032             {
2033                 tmp = stack.back();
2034                 stack.pop_back();
2035                 stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx);
2036             }
2037             break;
2038 
2039         //----------------------------------------------------------------------
2040         // OPCODE: DW_OP_shr
2041         // OPERANDS: none
2042         // DESCRIPTION: pops the top two stack entries, shifts the former second
2043         // entry right logically (filling with zero bits) by the number of bits
2044         // specified by the former top of the stack, and pushes the result.
2045         //----------------------------------------------------------------------
2046         case DW_OP_shr:
2047             if (stack.size() < 2)
2048             {
2049                 if (error_ptr)
2050                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shr.");
2051                 return false;
2052             }
2053             else
2054             {
2055                 tmp = stack.back();
2056                 stack.pop_back();
2057                 if (stack.back().ResolveValue(exe_ctx).ShiftRightLogical(tmp.ResolveValue(exe_ctx)) == false)
2058                 {
2059                     if (error_ptr)
2060                         error_ptr->SetErrorString("DW_OP_shr failed.");
2061                     return false;
2062                 }
2063             }
2064             break;
2065 
2066         //----------------------------------------------------------------------
2067         // OPCODE: DW_OP_shra
2068         // OPERANDS: none
2069         // DESCRIPTION: pops the top two stack entries, shifts the former second
2070         // entry right arithmetically (divide the magnitude by 2, keep the same
2071         // sign for the result) by the number of bits specified by the former
2072         // top of the stack, and pushes the result.
2073         //----------------------------------------------------------------------
2074         case DW_OP_shra:
2075             if (stack.size() < 2)
2076             {
2077                 if (error_ptr)
2078                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shra.");
2079                 return false;
2080             }
2081             else
2082             {
2083                 tmp = stack.back();
2084                 stack.pop_back();
2085                 stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx);
2086             }
2087             break;
2088 
2089         //----------------------------------------------------------------------
2090         // OPCODE: DW_OP_xor
2091         // OPERANDS: none
2092         // DESCRIPTION: pops the top two stack entries, performs the bitwise
2093         // exclusive-or operation on the two, and pushes the result.
2094         //----------------------------------------------------------------------
2095         case DW_OP_xor:
2096             if (stack.size() < 2)
2097             {
2098                 if (error_ptr)
2099                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_xor.");
2100                 return false;
2101             }
2102             else
2103             {
2104                 tmp = stack.back();
2105                 stack.pop_back();
2106                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx);
2107             }
2108             break;
2109 
2110 
2111         //----------------------------------------------------------------------
2112         // OPCODE: DW_OP_skip
2113         // OPERANDS: int16_t
2114         // DESCRIPTION:  An unconditional branch. Its single operand is a 2-byte
2115         // signed integer constant. The 2-byte constant is the number of bytes
2116         // of the DWARF expression to skip forward or backward from the current
2117         // operation, beginning after the 2-byte constant.
2118         //----------------------------------------------------------------------
2119         case DW_OP_skip:
2120             {
2121                 int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
2122                 lldb::offset_t new_offset = offset + skip_offset;
2123                 if (new_offset >= opcodes_offset && new_offset < end_offset)
2124                     offset = new_offset;
2125                 else
2126                 {
2127                     if (error_ptr)
2128                         error_ptr->SetErrorString("Invalid opcode offset in DW_OP_skip.");
2129                     return false;
2130                 }
2131             }
2132             break;
2133 
2134         //----------------------------------------------------------------------
2135         // OPCODE: DW_OP_bra
2136         // OPERANDS: int16_t
2137         // DESCRIPTION: A conditional branch. Its single operand is a 2-byte
2138         // signed integer constant. This operation pops the top of stack. If
2139         // the value popped is not the constant 0, the 2-byte constant operand
2140         // is the number of bytes of the DWARF expression to skip forward or
2141         // backward from the current operation, beginning after the 2-byte
2142         // constant.
2143         //----------------------------------------------------------------------
2144         case DW_OP_bra:
2145             {
2146                 tmp = stack.back();
2147                 stack.pop_back();
2148                 int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
2149                 Scalar zero(0);
2150                 if (tmp.ResolveValue(exe_ctx) != zero)
2151                 {
2152                     lldb::offset_t new_offset = offset + bra_offset;
2153                     if (new_offset >= opcodes_offset && new_offset < end_offset)
2154                         offset = new_offset;
2155                     else
2156                     {
2157                         if (error_ptr)
2158                             error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
2159                         return false;
2160                     }
2161                 }
2162             }
2163             break;
2164 
2165         //----------------------------------------------------------------------
2166         // OPCODE: DW_OP_eq
2167         // OPERANDS: none
2168         // DESCRIPTION: pops the top two stack values, compares using the
2169         // equals (==) operator.
2170         // STACK RESULT: push the constant value 1 onto the stack if the result
2171         // of the operation is true or the constant value 0 if the result of the
2172         // operation is false.
2173         //----------------------------------------------------------------------
2174         case DW_OP_eq:
2175             if (stack.size() < 2)
2176             {
2177                 if (error_ptr)
2178                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_eq.");
2179                 return false;
2180             }
2181             else
2182             {
2183                 tmp = stack.back();
2184                 stack.pop_back();
2185                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx);
2186             }
2187             break;
2188 
2189         //----------------------------------------------------------------------
2190         // OPCODE: DW_OP_ge
2191         // OPERANDS: none
2192         // DESCRIPTION: pops the top two stack values, compares using the
2193         // greater than or equal to (>=) operator.
2194         // STACK RESULT: push the constant value 1 onto the stack if the result
2195         // of the operation is true or the constant value 0 if the result of the
2196         // operation is false.
2197         //----------------------------------------------------------------------
2198         case DW_OP_ge:
2199             if (stack.size() < 2)
2200             {
2201                 if (error_ptr)
2202                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ge.");
2203                 return false;
2204             }
2205             else
2206             {
2207                 tmp = stack.back();
2208                 stack.pop_back();
2209                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx);
2210             }
2211             break;
2212 
2213         //----------------------------------------------------------------------
2214         // OPCODE: DW_OP_gt
2215         // OPERANDS: none
2216         // DESCRIPTION: pops the top two stack values, compares using the
2217         // greater than (>) operator.
2218         // STACK RESULT: push the constant value 1 onto the stack if the result
2219         // of the operation is true or the constant value 0 if the result of the
2220         // operation is false.
2221         //----------------------------------------------------------------------
2222         case DW_OP_gt:
2223             if (stack.size() < 2)
2224             {
2225                 if (error_ptr)
2226                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_gt.");
2227                 return false;
2228             }
2229             else
2230             {
2231                 tmp = stack.back();
2232                 stack.pop_back();
2233                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx);
2234             }
2235             break;
2236 
2237         //----------------------------------------------------------------------
2238         // OPCODE: DW_OP_le
2239         // OPERANDS: none
2240         // DESCRIPTION: pops the top two stack values, compares using the
2241         // less than or equal to (<=) operator.
2242         // STACK RESULT: push the constant value 1 onto the stack if the result
2243         // of the operation is true or the constant value 0 if the result of the
2244         // operation is false.
2245         //----------------------------------------------------------------------
2246         case DW_OP_le:
2247             if (stack.size() < 2)
2248             {
2249                 if (error_ptr)
2250                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_le.");
2251                 return false;
2252             }
2253             else
2254             {
2255                 tmp = stack.back();
2256                 stack.pop_back();
2257                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx);
2258             }
2259             break;
2260 
2261         //----------------------------------------------------------------------
2262         // OPCODE: DW_OP_lt
2263         // OPERANDS: none
2264         // DESCRIPTION: pops the top two stack values, compares using the
2265         // less than (<) operator.
2266         // STACK RESULT: push the constant value 1 onto the stack if the result
2267         // of the operation is true or the constant value 0 if the result of the
2268         // operation is false.
2269         //----------------------------------------------------------------------
2270         case DW_OP_lt:
2271             if (stack.size() < 2)
2272             {
2273                 if (error_ptr)
2274                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_lt.");
2275                 return false;
2276             }
2277             else
2278             {
2279                 tmp = stack.back();
2280                 stack.pop_back();
2281                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) < tmp.ResolveValue(exe_ctx);
2282             }
2283             break;
2284 
2285         //----------------------------------------------------------------------
2286         // OPCODE: DW_OP_ne
2287         // OPERANDS: none
2288         // DESCRIPTION: pops the top two stack values, compares using the
2289         // not equal (!=) operator.
2290         // STACK RESULT: push the constant value 1 onto the stack if the result
2291         // of the operation is true or the constant value 0 if the result of the
2292         // operation is false.
2293         //----------------------------------------------------------------------
2294         case DW_OP_ne:
2295             if (stack.size() < 2)
2296             {
2297                 if (error_ptr)
2298                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ne.");
2299                 return false;
2300             }
2301             else
2302             {
2303                 tmp = stack.back();
2304                 stack.pop_back();
2305                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) != tmp.ResolveValue(exe_ctx);
2306             }
2307             break;
2308 
2309         //----------------------------------------------------------------------
2310         // OPCODE: DW_OP_litn
2311         // OPERANDS: none
2312         // DESCRIPTION: encode the unsigned literal values from 0 through 31.
2313         // STACK RESULT: push the unsigned literal constant value onto the top
2314         // of the stack.
2315         //----------------------------------------------------------------------
2316         case DW_OP_lit0:
2317         case DW_OP_lit1:
2318         case DW_OP_lit2:
2319         case DW_OP_lit3:
2320         case DW_OP_lit4:
2321         case DW_OP_lit5:
2322         case DW_OP_lit6:
2323         case DW_OP_lit7:
2324         case DW_OP_lit8:
2325         case DW_OP_lit9:
2326         case DW_OP_lit10:
2327         case DW_OP_lit11:
2328         case DW_OP_lit12:
2329         case DW_OP_lit13:
2330         case DW_OP_lit14:
2331         case DW_OP_lit15:
2332         case DW_OP_lit16:
2333         case DW_OP_lit17:
2334         case DW_OP_lit18:
2335         case DW_OP_lit19:
2336         case DW_OP_lit20:
2337         case DW_OP_lit21:
2338         case DW_OP_lit22:
2339         case DW_OP_lit23:
2340         case DW_OP_lit24:
2341         case DW_OP_lit25:
2342         case DW_OP_lit26:
2343         case DW_OP_lit27:
2344         case DW_OP_lit28:
2345         case DW_OP_lit29:
2346         case DW_OP_lit30:
2347         case DW_OP_lit31:
2348             stack.push_back(Scalar(op - DW_OP_lit0));
2349             break;
2350 
2351         //----------------------------------------------------------------------
2352         // OPCODE: DW_OP_regN
2353         // OPERANDS: none
2354         // DESCRIPTION: Push the value in register n on the top of the stack.
2355         //----------------------------------------------------------------------
2356         case DW_OP_reg0:
2357         case DW_OP_reg1:
2358         case DW_OP_reg2:
2359         case DW_OP_reg3:
2360         case DW_OP_reg4:
2361         case DW_OP_reg5:
2362         case DW_OP_reg6:
2363         case DW_OP_reg7:
2364         case DW_OP_reg8:
2365         case DW_OP_reg9:
2366         case DW_OP_reg10:
2367         case DW_OP_reg11:
2368         case DW_OP_reg12:
2369         case DW_OP_reg13:
2370         case DW_OP_reg14:
2371         case DW_OP_reg15:
2372         case DW_OP_reg16:
2373         case DW_OP_reg17:
2374         case DW_OP_reg18:
2375         case DW_OP_reg19:
2376         case DW_OP_reg20:
2377         case DW_OP_reg21:
2378         case DW_OP_reg22:
2379         case DW_OP_reg23:
2380         case DW_OP_reg24:
2381         case DW_OP_reg25:
2382         case DW_OP_reg26:
2383         case DW_OP_reg27:
2384         case DW_OP_reg28:
2385         case DW_OP_reg29:
2386         case DW_OP_reg30:
2387         case DW_OP_reg31:
2388             {
2389                 reg_num = op - DW_OP_reg0;
2390 
2391                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2392                     stack.push_back(tmp);
2393                 else
2394                     return false;
2395             }
2396             break;
2397         //----------------------------------------------------------------------
2398         // OPCODE: DW_OP_regx
2399         // OPERANDS:
2400         //      ULEB128 literal operand that encodes the register.
2401         // DESCRIPTION: Push the value in register on the top of the stack.
2402         //----------------------------------------------------------------------
2403         case DW_OP_regx:
2404             {
2405                 reg_num = opcodes.GetULEB128(&offset);
2406                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2407                     stack.push_back(tmp);
2408                 else
2409                     return false;
2410             }
2411             break;
2412 
2413         //----------------------------------------------------------------------
2414         // OPCODE: DW_OP_bregN
2415         // OPERANDS:
2416         //      SLEB128 offset from register N
2417         // DESCRIPTION: Value is in memory at the address specified by register
2418         // N plus an offset.
2419         //----------------------------------------------------------------------
2420         case DW_OP_breg0:
2421         case DW_OP_breg1:
2422         case DW_OP_breg2:
2423         case DW_OP_breg3:
2424         case DW_OP_breg4:
2425         case DW_OP_breg5:
2426         case DW_OP_breg6:
2427         case DW_OP_breg7:
2428         case DW_OP_breg8:
2429         case DW_OP_breg9:
2430         case DW_OP_breg10:
2431         case DW_OP_breg11:
2432         case DW_OP_breg12:
2433         case DW_OP_breg13:
2434         case DW_OP_breg14:
2435         case DW_OP_breg15:
2436         case DW_OP_breg16:
2437         case DW_OP_breg17:
2438         case DW_OP_breg18:
2439         case DW_OP_breg19:
2440         case DW_OP_breg20:
2441         case DW_OP_breg21:
2442         case DW_OP_breg22:
2443         case DW_OP_breg23:
2444         case DW_OP_breg24:
2445         case DW_OP_breg25:
2446         case DW_OP_breg26:
2447         case DW_OP_breg27:
2448         case DW_OP_breg28:
2449         case DW_OP_breg29:
2450         case DW_OP_breg30:
2451         case DW_OP_breg31:
2452             {
2453                 reg_num = op - DW_OP_breg0;
2454 
2455                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2456                 {
2457                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2458                     tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
2459                     tmp.ClearContext();
2460                     stack.push_back(tmp);
2461                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2462                 }
2463                 else
2464                     return false;
2465             }
2466             break;
2467         //----------------------------------------------------------------------
2468         // OPCODE: DW_OP_bregx
2469         // OPERANDS: 2
2470         //      ULEB128 literal operand that encodes the register.
2471         //      SLEB128 offset from register N
2472         // DESCRIPTION: Value is in memory at the address specified by register
2473         // N plus an offset.
2474         //----------------------------------------------------------------------
2475         case DW_OP_bregx:
2476             {
2477                 reg_num = opcodes.GetULEB128(&offset);
2478 
2479                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
2480                 {
2481                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
2482                     tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
2483                     tmp.ClearContext();
2484                     stack.push_back(tmp);
2485                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
2486                 }
2487                 else
2488                     return false;
2489             }
2490             break;
2491 
2492         case DW_OP_fbreg:
2493             if (exe_ctx)
2494             {
2495                 if (frame)
2496                 {
2497                     Scalar value;
2498                     if (frame->GetFrameBaseValue(value, error_ptr))
2499                     {
2500                         int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
2501                         value += fbreg_offset;
2502                         stack.push_back(value);
2503                         stack.back().SetValueType (Value::eValueTypeLoadAddress);
2504                     }
2505                     else
2506                         return false;
2507                 }
2508                 else
2509                 {
2510                     if (error_ptr)
2511                         error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_fbreg opcode.");
2512                     return false;
2513                 }
2514             }
2515             else
2516             {
2517                 if (error_ptr)
2518                     error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_fbreg.\n");
2519                 return false;
2520             }
2521 
2522             break;
2523 
2524         //----------------------------------------------------------------------
2525         // OPCODE: DW_OP_nop
2526         // OPERANDS: none
2527         // DESCRIPTION: A place holder. It has no effect on the location stack
2528         // or any of its values.
2529         //----------------------------------------------------------------------
2530         case DW_OP_nop:
2531             break;
2532 
2533         //----------------------------------------------------------------------
2534         // OPCODE: DW_OP_piece
2535         // OPERANDS: 1
2536         //      ULEB128: byte size of the piece
2537         // DESCRIPTION: The operand describes the size in bytes of the piece of
2538         // the object referenced by the DWARF expression whose result is at the
2539         // top of the stack. If the piece is located in a register, but does not
2540         // occupy the entire register, the placement of the piece within that
2541         // register is defined by the ABI.
2542         //
2543         // Many compilers store a single variable in sets of registers, or store
2544         // a variable partially in memory and partially in registers.
2545         // DW_OP_piece provides a way of describing how large a part of a
2546         // variable a particular DWARF expression refers to.
2547         //----------------------------------------------------------------------
2548         case DW_OP_piece:
2549             if (error_ptr)
2550                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_piece.");
2551             return false;
2552 
2553         //----------------------------------------------------------------------
2554         // OPCODE: DW_OP_push_object_address
2555         // OPERANDS: none
2556         // DESCRIPTION: Pushes the address of the object currently being
2557         // evaluated as part of evaluation of a user presented expression.
2558         // This object may correspond to an independent variable described by
2559         // its own DIE or it may be a component of an array, structure, or class
2560         // whose address has been dynamically determined by an earlier step
2561         // during user expression evaluation.
2562         //----------------------------------------------------------------------
2563         case DW_OP_push_object_address:
2564             if (error_ptr)
2565                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_push_object_address.");
2566             return false;
2567 
2568         //----------------------------------------------------------------------
2569         // OPCODE: DW_OP_call2
2570         // OPERANDS:
2571         //      uint16_t compile unit relative offset of a DIE
2572         // DESCRIPTION: Performs subroutine calls during evaluation
2573         // of a DWARF expression. The operand is the 2-byte unsigned offset
2574         // of a debugging information entry in the current compilation unit.
2575         //
2576         // Operand interpretation is exactly like that for DW_FORM_ref2.
2577         //
2578         // This operation transfers control of DWARF expression evaluation
2579         // to the DW_AT_location attribute of the referenced DIE. If there is
2580         // no such attribute, then there is no effect. Execution of the DWARF
2581         // expression of a DW_AT_location attribute may add to and/or remove from
2582         // values on the stack. Execution returns to the point following the call
2583         // when the end of the attribute is reached. Values on the stack at the
2584         // time of the call may be used as parameters by the called expression
2585         // and values left on the stack by the called expression may be used as
2586         // return values by prior agreement between the calling and called
2587         // expressions.
2588         //----------------------------------------------------------------------
2589         case DW_OP_call2:
2590             if (error_ptr)
2591                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call2.");
2592             return false;
2593         //----------------------------------------------------------------------
2594         // OPCODE: DW_OP_call4
2595         // OPERANDS: 1
2596         //      uint32_t compile unit relative offset of a DIE
2597         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2598         // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset
2599         // of a debugging information entry in  the current compilation unit.
2600         //
2601         // Operand interpretation DW_OP_call4 is exactly like that for
2602         // DW_FORM_ref4.
2603         //
2604         // This operation transfers control of DWARF expression evaluation
2605         // to the DW_AT_location attribute of the referenced DIE. If there is
2606         // no such attribute, then there is no effect. Execution of the DWARF
2607         // expression of a DW_AT_location attribute may add to and/or remove from
2608         // values on the stack. Execution returns to the point following the call
2609         // when the end of the attribute is reached. Values on the stack at the
2610         // time of the call may be used as parameters by the called expression
2611         // and values left on the stack by the called expression may be used as
2612         // return values by prior agreement between the calling and called
2613         // expressions.
2614         //----------------------------------------------------------------------
2615         case DW_OP_call4:
2616             if (error_ptr)
2617                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call4.");
2618             return false;
2619 
2620         //----------------------------------------------------------------------
2621         // OPCODE: DW_OP_stack_value
2622         // OPERANDS: None
2623         // DESCRIPTION: Specifies that the object does not exist in memory but
2624         // rather is a constant value.  The value from the top of the stack is
2625         // the value to be used.  This is the actual object value and not the
2626         // location.
2627         //----------------------------------------------------------------------
2628         case DW_OP_stack_value:
2629             stack.back().SetValueType(Value::eValueTypeScalar);
2630             break;
2631 
2632         //----------------------------------------------------------------------
2633         // OPCODE: DW_OP_call_frame_cfa
2634         // OPERANDS: None
2635         // DESCRIPTION: Specifies a DWARF expression that pushes the value of
2636         // the canonical frame address consistent with the call frame information
2637         // located in .debug_frame (or in the FDEs of the eh_frame section).
2638         //----------------------------------------------------------------------
2639         case DW_OP_call_frame_cfa:
2640             if (frame)
2641             {
2642                 // Note that we don't have to parse FDEs because this DWARF expression
2643                 // is commonly evaluated with a valid stack frame.
2644                 StackID id = frame->GetStackID();
2645                 addr_t cfa = id.GetCallFrameAddress();
2646                 if (cfa != LLDB_INVALID_ADDRESS)
2647                 {
2648                     stack.push_back(Scalar(cfa));
2649                     stack.back().SetValueType (Value::eValueTypeHostAddress);
2650                 }
2651                 else
2652                     if (error_ptr)
2653                         error_ptr->SetErrorString ("Stack frame does not include a canonical frame address for DW_OP_call_frame_cfa opcode.");
2654             }
2655             else
2656             {
2657                 if (error_ptr)
2658                     error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_call_frame_cfa opcode.");
2659                 return false;
2660             }
2661             break;
2662         default:
2663             if (log)
2664                 log->Printf("Unhandled opcode %s in DWARFExpression.", DW_OP_value_to_name(op));
2665             break;
2666         }
2667     }
2668 
2669     if (stack.empty())
2670     {
2671         if (error_ptr)
2672             error_ptr->SetErrorString ("Stack empty after evaluation.");
2673         return false;
2674     }
2675     else if (log && log->GetVerbose())
2676     {
2677         size_t count = stack.size();
2678         log->Printf("Stack after operation has %lu values:", count);
2679         for (size_t i=0; i<count; ++i)
2680         {
2681             StreamString new_value;
2682             new_value.Printf("[%" PRIu64 "]", (uint64_t)i);
2683             stack[i].Dump(&new_value);
2684             log->Printf("  %s", new_value.GetData());
2685         }
2686     }
2687 
2688     result = stack.back();
2689     return true;    // Return true on success
2690 }
2691 
2692