1 //===-- DWARFFormValue.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 <assert.h>
11
12 #include "lldb/Core/dwarf.h"
13 #include "lldb/Core/Stream.h"
14
15 #include "DWARFFormValue.h"
16 #include "DWARFCompileUnit.h"
17
18 class DWARFCompileUnit;
19
20 using namespace lldb_private;
21
22
23 static uint8_t g_form_sizes_addr4[] =
24 {
25 0, // 0x00 unused
26 4, // 0x01 DW_FORM_addr
27 0, // 0x02 unused
28 0, // 0x03 DW_FORM_block2
29 0, // 0x04 DW_FORM_block4
30 2, // 0x05 DW_FORM_data2
31 4, // 0x06 DW_FORM_data4
32 8, // 0x07 DW_FORM_data8
33 0, // 0x08 DW_FORM_string
34 0, // 0x09 DW_FORM_block
35 0, // 0x0a DW_FORM_block1
36 1, // 0x0b DW_FORM_data1
37 1, // 0x0c DW_FORM_flag
38 0, // 0x0d DW_FORM_sdata
39 4, // 0x0e DW_FORM_strp
40 0, // 0x0f DW_FORM_udata
41 0, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later
42 1, // 0x11 DW_FORM_ref1
43 2, // 0x12 DW_FORM_ref2
44 4, // 0x13 DW_FORM_ref4
45 8, // 0x14 DW_FORM_ref8
46 0, // 0x15 DW_FORM_ref_udata
47 0, // 0x16 DW_FORM_indirect
48 4, // 0x17 DW_FORM_sec_offset
49 0, // 0x18 DW_FORM_exprloc
50 0, // 0x19 DW_FORM_flag_present
51 0, // 0x1a
52 0, // 0x1b
53 0, // 0x1c
54 0, // 0x1d
55 0, // 0x1e
56 0, // 0x1f
57 8, // 0x20 DW_FORM_ref_sig8
58
59 };
60
61 static uint8_t
62 g_form_sizes_addr8[] =
63 {
64 0, // 0x00 unused
65 8, // 0x01 DW_FORM_addr
66 0, // 0x02 unused
67 0, // 0x03 DW_FORM_block2
68 0, // 0x04 DW_FORM_block4
69 2, // 0x05 DW_FORM_data2
70 4, // 0x06 DW_FORM_data4
71 8, // 0x07 DW_FORM_data8
72 0, // 0x08 DW_FORM_string
73 0, // 0x09 DW_FORM_block
74 0, // 0x0a DW_FORM_block1
75 1, // 0x0b DW_FORM_data1
76 1, // 0x0c DW_FORM_flag
77 0, // 0x0d DW_FORM_sdata
78 4, // 0x0e DW_FORM_strp
79 0, // 0x0f DW_FORM_udata
80 0, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later
81 1, // 0x11 DW_FORM_ref1
82 2, // 0x12 DW_FORM_ref2
83 4, // 0x13 DW_FORM_ref4
84 8, // 0x14 DW_FORM_ref8
85 0, // 0x15 DW_FORM_ref_udata
86 0, // 0x16 DW_FORM_indirect
87 4, // 0x17 DW_FORM_sec_offset
88 0, // 0x18 DW_FORM_exprloc
89 0, // 0x19 DW_FORM_flag_present
90 0, // 0x1a
91 0, // 0x1b
92 0, // 0x1c
93 0, // 0x1d
94 0, // 0x1e
95 0, // 0x1f
96 8, // 0x20 DW_FORM_ref_sig8
97 };
98
99 const uint8_t *
GetFixedFormSizesForAddressSize(uint8_t addr_size)100 DWARFFormValue::GetFixedFormSizesForAddressSize (uint8_t addr_size)
101 {
102 switch (addr_size)
103 {
104 case 4: return g_form_sizes_addr4;
105 case 8: return g_form_sizes_addr8;
106 }
107 return NULL;
108 }
109
DWARFFormValue(dw_form_t form)110 DWARFFormValue::DWARFFormValue(dw_form_t form) :
111 m_form(form),
112 m_value()
113 {
114 }
115
116 bool
ExtractValue(const DataExtractor & data,lldb::offset_t * offset_ptr,const DWARFCompileUnit * cu)117 DWARFFormValue::ExtractValue(const DataExtractor& data, lldb::offset_t* offset_ptr, const DWARFCompileUnit* cu)
118 {
119 bool indirect = false;
120 bool is_block = false;
121 m_value.data = NULL;
122 // Read the value for the form into value and follow and DW_FORM_indirect instances we run into
123 do
124 {
125 indirect = false;
126 switch (m_form)
127 {
128 case DW_FORM_addr: m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::GetAddressByteSize(cu)); break;
129 case DW_FORM_block2: m_value.value.uval = data.GetU16(offset_ptr); is_block = true; break;
130 case DW_FORM_block4: m_value.value.uval = data.GetU32(offset_ptr); is_block = true; break;
131 case DW_FORM_data2: m_value.value.uval = data.GetU16(offset_ptr); break;
132 case DW_FORM_data4: m_value.value.uval = data.GetU32(offset_ptr); break;
133 case DW_FORM_data8: m_value.value.uval = data.GetU64(offset_ptr); break;
134 case DW_FORM_string: m_value.value.cstr = data.GetCStr(offset_ptr);
135 // Set the string value to also be the data for inlined cstr form values only
136 // so we can tell the differnence between DW_FORM_string and DW_FORM_strp form
137 // values;
138 m_value.data = (uint8_t*)m_value.value.cstr; break;
139 case DW_FORM_exprloc:
140 case DW_FORM_block: m_value.value.uval = data.GetULEB128(offset_ptr); is_block = true; break;
141 case DW_FORM_block1: m_value.value.uval = data.GetU8(offset_ptr); is_block = true; break;
142 case DW_FORM_data1: m_value.value.uval = data.GetU8(offset_ptr); break;
143 case DW_FORM_flag: m_value.value.uval = data.GetU8(offset_ptr); break;
144 case DW_FORM_sdata: m_value.value.sval = data.GetSLEB128(offset_ptr); break;
145 case DW_FORM_strp: m_value.value.uval = data.GetU32(offset_ptr); break;
146 // case DW_FORM_APPLE_db_str:
147 case DW_FORM_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break;
148 case DW_FORM_ref_addr:
149 if (cu->GetVersion() <= 2)
150 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::GetAddressByteSize(cu));
151 else
152 m_value.value.uval = data.GetU32(offset_ptr); // 4 for DWARF32, 8 for DWARF64, but we don't support DWARF64 yet
153 break;
154 case DW_FORM_ref1: m_value.value.uval = data.GetU8(offset_ptr); break;
155 case DW_FORM_ref2: m_value.value.uval = data.GetU16(offset_ptr); break;
156 case DW_FORM_ref4: m_value.value.uval = data.GetU32(offset_ptr); break;
157 case DW_FORM_ref8: m_value.value.uval = data.GetU64(offset_ptr); break;
158 case DW_FORM_ref_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break;
159 case DW_FORM_indirect:
160 m_form = data.GetULEB128(offset_ptr);
161 indirect = true;
162 break;
163
164 case DW_FORM_sec_offset: m_value.value.uval = data.GetU32(offset_ptr); break;
165 case DW_FORM_flag_present: m_value.value.uval = 1; break;
166 case DW_FORM_ref_sig8: m_value.value.uval = data.GetU64(offset_ptr); break;
167 default:
168 return false;
169 break;
170 }
171 } while (indirect);
172
173 if (is_block)
174 {
175 m_value.data = data.PeekData(*offset_ptr, m_value.value.uval);
176 if (m_value.data != NULL)
177 {
178 *offset_ptr += m_value.value.uval;
179 }
180 }
181
182 return true;
183 }
184
185 bool
SkipValue(const DataExtractor & debug_info_data,lldb::offset_t * offset_ptr,const DWARFCompileUnit * cu) const186 DWARFFormValue::SkipValue(const DataExtractor& debug_info_data, lldb::offset_t *offset_ptr, const DWARFCompileUnit* cu) const
187 {
188 return DWARFFormValue::SkipValue(m_form, debug_info_data, offset_ptr, cu);
189 }
190
191 bool
SkipValue(dw_form_t form,const DataExtractor & debug_info_data,lldb::offset_t * offset_ptr,const DWARFCompileUnit * cu)192 DWARFFormValue::SkipValue(dw_form_t form, const DataExtractor& debug_info_data, lldb::offset_t *offset_ptr, const DWARFCompileUnit* cu)
193 {
194 switch (form)
195 {
196 // Blocks if inlined data that have a length field and the data bytes
197 // inlined in the .debug_info
198 case DW_FORM_exprloc:
199 case DW_FORM_block: { dw_uleb128_t size = debug_info_data.GetULEB128(offset_ptr); *offset_ptr += size; } return true;
200 case DW_FORM_block1: { dw_uleb128_t size = debug_info_data.GetU8(offset_ptr); *offset_ptr += size; } return true;
201 case DW_FORM_block2: { dw_uleb128_t size = debug_info_data.GetU16(offset_ptr); *offset_ptr += size; } return true;
202 case DW_FORM_block4: { dw_uleb128_t size = debug_info_data.GetU32(offset_ptr); *offset_ptr += size; } return true;
203
204 // Inlined NULL terminated C-strings
205 case DW_FORM_string:
206 debug_info_data.GetCStr(offset_ptr);
207 return true;
208
209 // Compile unit address sized values
210 case DW_FORM_addr:
211 *offset_ptr += DWARFCompileUnit::GetAddressByteSize(cu);
212 return true;
213
214 case DW_FORM_ref_addr:
215 if (cu->GetVersion() <= 2)
216 *offset_ptr += DWARFCompileUnit::GetAddressByteSize(cu);
217 else
218 *offset_ptr += 4;// 4 for DWARF32, 8 for DWARF64, but we don't support DWARF64 yet
219 return true;
220
221 // 0 bytes values (implied from DW_FORM)
222 case DW_FORM_flag_present:
223 return true;
224
225 // 1 byte values
226 case DW_FORM_data1:
227 case DW_FORM_flag:
228 case DW_FORM_ref1:
229 *offset_ptr += 1;
230 return true;
231
232 // 2 byte values
233 case DW_FORM_data2:
234 case DW_FORM_ref2:
235 *offset_ptr += 2;
236 return true;
237
238 // 32 bit for DWARF 32, 64 for DWARF 64
239 case DW_FORM_sec_offset:
240 *offset_ptr += 4;
241 return true;
242
243 // 4 byte values
244 case DW_FORM_strp:
245 case DW_FORM_data4:
246 case DW_FORM_ref4:
247 *offset_ptr += 4;
248 return true;
249
250 // 8 byte values
251 case DW_FORM_data8:
252 case DW_FORM_ref8:
253 case DW_FORM_ref_sig8:
254 *offset_ptr += 8;
255 return true;
256
257 // signed or unsigned LEB 128 values
258 case DW_FORM_sdata:
259 case DW_FORM_udata:
260 case DW_FORM_ref_udata:
261 debug_info_data.Skip_LEB128(offset_ptr);
262 return true;
263
264 case DW_FORM_indirect:
265 {
266 dw_form_t indirect_form = debug_info_data.GetULEB128(offset_ptr);
267 return DWARFFormValue::SkipValue (indirect_form,
268 debug_info_data,
269 offset_ptr,
270 cu);
271 }
272
273 default:
274 break;
275 }
276 return false;
277 }
278
279
280 void
Dump(Stream & s,const DataExtractor * debug_str_data,const DWARFCompileUnit * cu) const281 DWARFFormValue::Dump(Stream &s, const DataExtractor* debug_str_data, const DWARFCompileUnit* cu) const
282 {
283 uint64_t uvalue = Unsigned();
284 bool cu_relative_offset = false;
285
286 bool verbose = s.GetVerbose();
287
288 switch (m_form)
289 {
290 case DW_FORM_addr: s.Address(uvalue, sizeof (uint64_t)); break;
291 case DW_FORM_flag:
292 case DW_FORM_data1: s.PutHex8(uvalue); break;
293 case DW_FORM_data2: s.PutHex16(uvalue); break;
294 case DW_FORM_sec_offset:
295 case DW_FORM_data4: s.PutHex32(uvalue); break;
296 case DW_FORM_ref_sig8:
297 case DW_FORM_data8: s.PutHex64(uvalue); break;
298 case DW_FORM_string: s.QuotedCString(AsCString(NULL)); break;
299 case DW_FORM_exprloc:
300 case DW_FORM_block:
301 case DW_FORM_block1:
302 case DW_FORM_block2:
303 case DW_FORM_block4:
304 if (uvalue > 0)
305 {
306 switch (m_form)
307 {
308 case DW_FORM_exprloc:
309 case DW_FORM_block: s.Printf("<0x%" PRIx64 "> ", uvalue); break;
310 case DW_FORM_block1: s.Printf("<0x%2.2x> ", (uint8_t)uvalue); break;
311 case DW_FORM_block2: s.Printf("<0x%4.4x> ", (uint16_t)uvalue); break;
312 case DW_FORM_block4: s.Printf("<0x%8.8x> ", (uint32_t)uvalue); break;
313 default: break;
314 }
315
316 const uint8_t* data_ptr = m_value.data;
317 if (data_ptr)
318 {
319 const uint8_t* end_data_ptr = data_ptr + uvalue; // uvalue contains size of block
320 while (data_ptr < end_data_ptr)
321 {
322 s.Printf("%2.2x ", *data_ptr);
323 ++data_ptr;
324 }
325 }
326 else
327 s.PutCString("NULL");
328 }
329 break;
330
331 case DW_FORM_sdata: s.PutSLEB128(uvalue); break;
332 case DW_FORM_udata: s.PutULEB128(uvalue); break;
333 case DW_FORM_strp:
334 if (debug_str_data)
335 {
336 if (verbose)
337 s.Printf(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
338
339 const char* dbg_str = AsCString(debug_str_data);
340 if (dbg_str)
341 s.QuotedCString(dbg_str);
342 }
343 else
344 {
345 s.PutHex32(uvalue);
346 }
347 break;
348
349 case DW_FORM_ref_addr:
350 {
351 if (cu->GetVersion() <= 2)
352 s.Address(uvalue, sizeof (uint64_t) * 2);
353 else
354 s.Address(uvalue, 4 * 2);// 4 for DWARF32, 8 for DWARF64, but we don't support DWARF64 yet
355 break;
356 }
357 case DW_FORM_ref1: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%2.2x", (uint8_t)uvalue); break;
358 case DW_FORM_ref2: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%4.4x", (uint16_t)uvalue); break;
359 case DW_FORM_ref4: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%4.4x", (uint32_t)uvalue); break;
360 case DW_FORM_ref8: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%8.8" PRIx64, uvalue); break;
361 case DW_FORM_ref_udata: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%" PRIx64, uvalue); break;
362
363 // All DW_FORM_indirect attributes should be resolved prior to calling this function
364 case DW_FORM_indirect: s.PutCString("DW_FORM_indirect"); break;
365 case DW_FORM_flag_present: break;
366 default:
367 s.Printf("DW_FORM(0x%4.4x)", m_form);
368 break;
369 }
370
371 if (cu_relative_offset)
372 {
373 if (verbose)
374 s.PutCString(" => ");
375
376 s.Printf("{0x%8.8" PRIx64 "}", (uvalue + (cu ? cu->GetOffset() : 0)));
377 }
378 }
379
380 const char*
AsCString(const DataExtractor * debug_str_data_ptr) const381 DWARFFormValue::AsCString(const DataExtractor* debug_str_data_ptr) const
382 {
383 if (IsInlinedCStr())
384 return m_value.value.cstr;
385 else if (debug_str_data_ptr)
386 return debug_str_data_ptr->PeekCStr(m_value.value.uval);
387 return NULL;
388 }
389
390 uint64_t
Reference(const DWARFCompileUnit * cu) const391 DWARFFormValue::Reference(const DWARFCompileUnit* cu) const
392 {
393 uint64_t die_offset = m_value.value.uval;
394 switch (m_form)
395 {
396 case DW_FORM_ref1:
397 case DW_FORM_ref2:
398 case DW_FORM_ref4:
399 case DW_FORM_ref8:
400 case DW_FORM_ref_udata:
401 die_offset += (cu ? cu->GetOffset() : 0);
402 break;
403
404 default:
405 break;
406 }
407
408 return die_offset;
409 }
410
411 uint64_t
Reference(dw_offset_t base_offset) const412 DWARFFormValue::Reference (dw_offset_t base_offset) const
413 {
414 uint64_t die_offset = m_value.value.uval;
415 switch (m_form)
416 {
417 case DW_FORM_ref1:
418 case DW_FORM_ref2:
419 case DW_FORM_ref4:
420 case DW_FORM_ref8:
421 case DW_FORM_ref_udata:
422 die_offset += base_offset;
423 break;
424
425 default:
426 break;
427 }
428
429 return die_offset;
430 }
431
432 //----------------------------------------------------------------------
433 // Resolve any compile unit specific references so that we don't need
434 // the compile unit at a later time in order to work with the form
435 // value.
436 //----------------------------------------------------------------------
437 bool
ResolveCompileUnitReferences(const DWARFCompileUnit * cu)438 DWARFFormValue::ResolveCompileUnitReferences(const DWARFCompileUnit* cu)
439 {
440 switch (m_form)
441 {
442 case DW_FORM_ref1:
443 case DW_FORM_ref2:
444 case DW_FORM_ref4:
445 case DW_FORM_ref8:
446 case DW_FORM_ref_udata:
447 m_value.value.uval += cu->GetOffset();
448 m_form = DW_FORM_ref_addr;
449 return true;
450 break;
451
452 default:
453 break;
454 }
455
456 return false;
457 }
458
459 const uint8_t*
BlockData() const460 DWARFFormValue::BlockData() const
461 {
462 if (!IsInlinedCStr())
463 return m_value.data;
464 return NULL;
465 }
466
467
468 bool
IsBlockForm(const dw_form_t form)469 DWARFFormValue::IsBlockForm(const dw_form_t form)
470 {
471 switch (form)
472 {
473 case DW_FORM_block:
474 case DW_FORM_block1:
475 case DW_FORM_block2:
476 case DW_FORM_block4:
477 return true;
478 }
479 return false;
480 }
481
482 bool
IsDataForm(const dw_form_t form)483 DWARFFormValue::IsDataForm(const dw_form_t form)
484 {
485 switch (form)
486 {
487 case DW_FORM_sdata:
488 case DW_FORM_udata:
489 case DW_FORM_data1:
490 case DW_FORM_data2:
491 case DW_FORM_data4:
492 case DW_FORM_data8:
493 return true;
494 }
495 return false;
496 }
497
498 int
Compare(const DWARFFormValue & a_value,const DWARFFormValue & b_value,const DWARFCompileUnit * a_cu,const DWARFCompileUnit * b_cu,const DataExtractor * debug_str_data_ptr)499 DWARFFormValue::Compare (const DWARFFormValue& a_value, const DWARFFormValue& b_value, const DWARFCompileUnit* a_cu, const DWARFCompileUnit* b_cu, const DataExtractor* debug_str_data_ptr)
500 {
501 dw_form_t a_form = a_value.Form();
502 dw_form_t b_form = b_value.Form();
503 if (a_form < b_form)
504 return -1;
505 if (a_form > b_form)
506 return 1;
507 switch (a_form)
508 {
509 case DW_FORM_addr:
510 case DW_FORM_flag:
511 case DW_FORM_data1:
512 case DW_FORM_data2:
513 case DW_FORM_data4:
514 case DW_FORM_data8:
515 case DW_FORM_udata:
516 case DW_FORM_ref_addr:
517 case DW_FORM_sec_offset:
518 case DW_FORM_flag_present:
519 case DW_FORM_ref_sig8:
520 {
521 uint64_t a = a_value.Unsigned();
522 uint64_t b = b_value.Unsigned();
523 if (a < b)
524 return -1;
525 if (a > b)
526 return 1;
527 return 0;
528 }
529
530 case DW_FORM_sdata:
531 {
532 int64_t a = a_value.Signed();
533 int64_t b = b_value.Signed();
534 if (a < b)
535 return -1;
536 if (a > b)
537 return 1;
538 return 0;
539 }
540
541 case DW_FORM_string:
542 case DW_FORM_strp:
543 {
544 const char *a_string = a_value.AsCString(debug_str_data_ptr);
545 const char *b_string = b_value.AsCString(debug_str_data_ptr);
546 if (a_string == b_string)
547 return 0;
548 else if (a_string && b_string)
549 return strcmp(a_string, b_string);
550 else if (a_string == NULL)
551 return -1; // A string is NULL, and B is valid
552 else
553 return 1; // A string valid, and B is NULL
554 }
555
556
557 case DW_FORM_block:
558 case DW_FORM_block1:
559 case DW_FORM_block2:
560 case DW_FORM_block4:
561 case DW_FORM_exprloc:
562 {
563 uint64_t a_len = a_value.Unsigned();
564 uint64_t b_len = b_value.Unsigned();
565 if (a_len < b_len)
566 return -1;
567 if (a_len > b_len)
568 return 1;
569 // The block lengths are the same
570 return memcmp(a_value.BlockData(), b_value.BlockData(), a_value.Unsigned());
571 }
572 break;
573
574 case DW_FORM_ref1:
575 case DW_FORM_ref2:
576 case DW_FORM_ref4:
577 case DW_FORM_ref8:
578 case DW_FORM_ref_udata:
579 {
580 uint64_t a = a_value.Reference(a_cu);
581 uint64_t b = b_value.Reference(b_cu);
582 if (a < b)
583 return -1;
584 if (a > b)
585 return 1;
586 return 0;
587 }
588
589 case DW_FORM_indirect:
590 assert(!"This shouldn't happen after the form has been extracted...");
591 break;
592
593 default:
594 assert(!"Unhandled DW_FORM");
595 break;
596 }
597 return -1;
598 }
599
600