1 //===-- DWARFDebugInfoEntry.cpp -------------------------------------------===//
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 "DWARFDebugInfoEntry.h"
11 #include "DWARFCompileUnit.h"
12 #include "DWARFContext.h"
13 #include "DWARFDebugAbbrev.h"
14 #include "DWARFFormValue.h"
15 #include "llvm/Support/Dwarf.h"
16 #include "llvm/Support/Format.h"
17 #include "llvm/Support/raw_ostream.h"
18 using namespace llvm;
19 using namespace dwarf;
20
dump(raw_ostream & OS,const DWARFCompileUnit * cu,unsigned recurseDepth,unsigned indent) const21 void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS,
22 const DWARFCompileUnit *cu,
23 unsigned recurseDepth,
24 unsigned indent) const {
25 DataExtractor debug_info_data = cu->getDebugInfoExtractor();
26 uint32_t offset = Offset;
27
28 if (debug_info_data.isValidOffset(offset)) {
29 uint32_t abbrCode = debug_info_data.getULEB128(&offset);
30
31 OS << format("\n0x%8.8x: ", Offset);
32 if (abbrCode) {
33 if (AbbrevDecl) {
34 const char *tagString = TagString(getTag());
35 if (tagString)
36 OS.indent(indent) << tagString;
37 else
38 OS.indent(indent) << format("DW_TAG_Unknown_%x", getTag());
39 OS << format(" [%u] %c\n", abbrCode,
40 AbbrevDecl->hasChildren() ? '*' : ' ');
41
42 // Dump all data in the .debug_info for the attributes
43 const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
44 for (uint32_t i = 0; i != numAttributes; ++i) {
45 uint16_t attr = AbbrevDecl->getAttrByIndex(i);
46 uint16_t form = AbbrevDecl->getFormByIndex(i);
47 dumpAttribute(OS, cu, &offset, attr, form, indent);
48 }
49
50 const DWARFDebugInfoEntryMinimal *child = getFirstChild();
51 if (recurseDepth > 0 && child) {
52 while (child) {
53 child->dump(OS, cu, recurseDepth-1, indent+2);
54 child = child->getSibling();
55 }
56 }
57 } else {
58 OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
59 << abbrCode << '\n';
60 }
61 } else {
62 OS.indent(indent) << "NULL\n";
63 }
64 }
65 }
66
dumpAttribute(raw_ostream & OS,const DWARFCompileUnit * cu,uint32_t * offset_ptr,uint16_t attr,uint16_t form,unsigned indent) const67 void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
68 const DWARFCompileUnit *cu,
69 uint32_t* offset_ptr,
70 uint16_t attr,
71 uint16_t form,
72 unsigned indent) const {
73 OS << format("0x%8.8x: ", *offset_ptr);
74 OS.indent(indent+2);
75 const char *attrString = AttributeString(attr);
76 if (attrString)
77 OS << attrString;
78 else
79 OS << format("DW_AT_Unknown_%x", attr);
80 const char *formString = FormEncodingString(form);
81 if (formString)
82 OS << " [" << formString << ']';
83 else
84 OS << format(" [DW_FORM_Unknown_%x]", form);
85
86 DWARFFormValue formValue(form);
87
88 if (!formValue.extractValue(cu->getDebugInfoExtractor(), offset_ptr, cu))
89 return;
90
91 OS << "\t(";
92 formValue.dump(OS, cu);
93 OS << ")\n";
94 }
95
extractFast(const DWARFCompileUnit * cu,const uint8_t * fixed_form_sizes,uint32_t * offset_ptr)96 bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFCompileUnit *cu,
97 const uint8_t *fixed_form_sizes,
98 uint32_t *offset_ptr) {
99 Offset = *offset_ptr;
100
101 DataExtractor debug_info_data = cu->getDebugInfoExtractor();
102 uint64_t abbrCode = debug_info_data.getULEB128(offset_ptr);
103
104 assert(fixed_form_sizes); // For best performance this should be specified!
105
106 if (abbrCode) {
107 uint32_t offset = *offset_ptr;
108
109 AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
110
111 // Skip all data in the .debug_info for the attributes
112 const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
113 uint32_t i;
114 uint16_t form;
115 for (i=0; i<numAttributes; ++i) {
116 form = AbbrevDecl->getFormByIndex(i);
117
118 const uint8_t fixed_skip_size = fixed_form_sizes[form];
119 if (fixed_skip_size)
120 offset += fixed_skip_size;
121 else {
122 bool form_is_indirect = false;
123 do {
124 form_is_indirect = false;
125 uint32_t form_size = 0;
126 switch (form) {
127 // Blocks if inlined data that have a length field and the data bytes
128 // inlined in the .debug_info.
129 case DW_FORM_exprloc:
130 case DW_FORM_block:
131 form_size = debug_info_data.getULEB128(&offset);
132 break;
133 case DW_FORM_block1:
134 form_size = debug_info_data.getU8(&offset);
135 break;
136 case DW_FORM_block2:
137 form_size = debug_info_data.getU16(&offset);
138 break;
139 case DW_FORM_block4:
140 form_size = debug_info_data.getU32(&offset);
141 break;
142
143 // Inlined NULL terminated C-strings
144 case DW_FORM_string:
145 debug_info_data.getCStr(&offset);
146 break;
147
148 // Compile unit address sized values
149 case DW_FORM_addr:
150 case DW_FORM_ref_addr:
151 form_size = cu->getAddressByteSize();
152 break;
153
154 // 0 sized form.
155 case DW_FORM_flag_present:
156 form_size = 0;
157 break;
158
159 // 1 byte values
160 case DW_FORM_data1:
161 case DW_FORM_flag:
162 case DW_FORM_ref1:
163 form_size = 1;
164 break;
165
166 // 2 byte values
167 case DW_FORM_data2:
168 case DW_FORM_ref2:
169 form_size = 2;
170 break;
171
172 // 4 byte values
173 case DW_FORM_strp:
174 case DW_FORM_data4:
175 case DW_FORM_ref4:
176 form_size = 4;
177 break;
178
179 // 8 byte values
180 case DW_FORM_data8:
181 case DW_FORM_ref8:
182 case DW_FORM_ref_sig8:
183 form_size = 8;
184 break;
185
186 // signed or unsigned LEB 128 values
187 case DW_FORM_sdata:
188 case DW_FORM_udata:
189 case DW_FORM_ref_udata:
190 debug_info_data.getULEB128(&offset);
191 break;
192
193 case DW_FORM_indirect:
194 form_is_indirect = true;
195 form = debug_info_data.getULEB128(&offset);
196 break;
197
198 case DW_FORM_sec_offset:
199 if (cu->getAddressByteSize() == 4)
200 debug_info_data.getU32(offset_ptr);
201 else
202 debug_info_data.getU64(offset_ptr);
203 break;
204
205 default:
206 *offset_ptr = Offset;
207 return false;
208 }
209 offset += form_size;
210
211 } while (form_is_indirect);
212 }
213 }
214 *offset_ptr = offset;
215 return true;
216 } else {
217 AbbrevDecl = NULL;
218 return true; // NULL debug tag entry
219 }
220 }
221
222 bool
extract(const DWARFCompileUnit * cu,uint32_t * offset_ptr)223 DWARFDebugInfoEntryMinimal::extract(const DWARFCompileUnit *cu,
224 uint32_t *offset_ptr) {
225 DataExtractor debug_info_data = cu->getDebugInfoExtractor();
226 const uint32_t cu_end_offset = cu->getNextCompileUnitOffset();
227 const uint8_t cu_addr_size = cu->getAddressByteSize();
228 uint32_t offset = *offset_ptr;
229 if ((offset < cu_end_offset) && debug_info_data.isValidOffset(offset)) {
230 Offset = offset;
231
232 uint64_t abbrCode = debug_info_data.getULEB128(&offset);
233
234 if (abbrCode) {
235 AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
236
237 if (AbbrevDecl) {
238 uint16_t tag = AbbrevDecl->getTag();
239
240 bool isCompileUnitTag = tag == DW_TAG_compile_unit;
241 if(cu && isCompileUnitTag)
242 const_cast<DWARFCompileUnit*>(cu)->setBaseAddress(0);
243
244 // Skip all data in the .debug_info for the attributes
245 const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
246 for (uint32_t i = 0; i != numAttributes; ++i) {
247 uint16_t attr = AbbrevDecl->getAttrByIndex(i);
248 uint16_t form = AbbrevDecl->getFormByIndex(i);
249
250 if (isCompileUnitTag &&
251 ((attr == DW_AT_entry_pc) || (attr == DW_AT_low_pc))) {
252 DWARFFormValue form_value(form);
253 if (form_value.extractValue(debug_info_data, &offset, cu)) {
254 if (attr == DW_AT_low_pc || attr == DW_AT_entry_pc)
255 const_cast<DWARFCompileUnit*>(cu)
256 ->setBaseAddress(form_value.getUnsigned());
257 }
258 } else {
259 bool form_is_indirect = false;
260 do {
261 form_is_indirect = false;
262 register uint32_t form_size = 0;
263 switch (form) {
264 // Blocks if inlined data that have a length field and the data
265 // bytes // inlined in the .debug_info
266 case DW_FORM_exprloc:
267 case DW_FORM_block:
268 form_size = debug_info_data.getULEB128(&offset);
269 break;
270 case DW_FORM_block1:
271 form_size = debug_info_data.getU8(&offset);
272 break;
273 case DW_FORM_block2:
274 form_size = debug_info_data.getU16(&offset);
275 break;
276 case DW_FORM_block4:
277 form_size = debug_info_data.getU32(&offset);
278 break;
279
280 // Inlined NULL terminated C-strings
281 case DW_FORM_string:
282 debug_info_data.getCStr(&offset);
283 break;
284
285 // Compile unit address sized values
286 case DW_FORM_addr:
287 case DW_FORM_ref_addr:
288 form_size = cu_addr_size;
289 break;
290
291 // 0 byte value
292 case DW_FORM_flag_present:
293 form_size = 0;
294 break;
295
296 // 1 byte values
297 case DW_FORM_data1:
298 case DW_FORM_flag:
299 case DW_FORM_ref1:
300 form_size = 1;
301 break;
302
303 // 2 byte values
304 case DW_FORM_data2:
305 case DW_FORM_ref2:
306 form_size = 2;
307 break;
308
309 // 4 byte values
310 case DW_FORM_strp:
311 form_size = 4;
312 break;
313
314 case DW_FORM_data4:
315 case DW_FORM_ref4:
316 form_size = 4;
317 break;
318
319 // 8 byte values
320 case DW_FORM_data8:
321 case DW_FORM_ref8:
322 case DW_FORM_ref_sig8:
323 form_size = 8;
324 break;
325
326 // signed or unsigned LEB 128 values
327 case DW_FORM_sdata:
328 case DW_FORM_udata:
329 case DW_FORM_ref_udata:
330 debug_info_data.getULEB128(&offset);
331 break;
332
333 case DW_FORM_indirect:
334 form = debug_info_data.getULEB128(&offset);
335 form_is_indirect = true;
336 break;
337
338 case DW_FORM_sec_offset:
339 if (cu->getAddressByteSize() == 4)
340 debug_info_data.getU32(offset_ptr);
341 else
342 debug_info_data.getU64(offset_ptr);
343 break;
344
345 default:
346 *offset_ptr = offset;
347 return false;
348 }
349
350 offset += form_size;
351 } while (form_is_indirect);
352 }
353 }
354 *offset_ptr = offset;
355 return true;
356 }
357 } else {
358 AbbrevDecl = NULL;
359 *offset_ptr = offset;
360 return true; // NULL debug tag entry
361 }
362 }
363
364 return false;
365 }
366
isSubprogramDIE() const367 bool DWARFDebugInfoEntryMinimal::isSubprogramDIE() const {
368 return getTag() == DW_TAG_subprogram;
369 }
370
isSubroutineDIE() const371 bool DWARFDebugInfoEntryMinimal::isSubroutineDIE() const {
372 uint32_t Tag = getTag();
373 return Tag == DW_TAG_subprogram ||
374 Tag == DW_TAG_inlined_subroutine;
375 }
376
377 uint32_t
getAttributeValue(const DWARFCompileUnit * cu,const uint16_t attr,DWARFFormValue & form_value,uint32_t * end_attr_offset_ptr) const378 DWARFDebugInfoEntryMinimal::getAttributeValue(const DWARFCompileUnit *cu,
379 const uint16_t attr,
380 DWARFFormValue &form_value,
381 uint32_t *end_attr_offset_ptr)
382 const {
383 if (AbbrevDecl) {
384 uint32_t attr_idx = AbbrevDecl->findAttributeIndex(attr);
385
386 if (attr_idx != -1U) {
387 uint32_t offset = getOffset();
388
389 DataExtractor debug_info_data = cu->getDebugInfoExtractor();
390
391 // Skip the abbreviation code so we are at the data for the attributes
392 debug_info_data.getULEB128(&offset);
393
394 uint32_t idx = 0;
395 while (idx < attr_idx)
396 DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(idx++),
397 debug_info_data, &offset, cu);
398
399 const uint32_t attr_offset = offset;
400 form_value = DWARFFormValue(AbbrevDecl->getFormByIndex(idx));
401 if (form_value.extractValue(debug_info_data, &offset, cu)) {
402 if (end_attr_offset_ptr)
403 *end_attr_offset_ptr = offset;
404 return attr_offset;
405 }
406 }
407 }
408
409 return 0;
410 }
411
412 const char*
getAttributeValueAsString(const DWARFCompileUnit * cu,const uint16_t attr,const char * fail_value) const413 DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
414 const DWARFCompileUnit* cu,
415 const uint16_t attr,
416 const char* fail_value) const {
417 DWARFFormValue form_value;
418 if (getAttributeValue(cu, attr, form_value)) {
419 DataExtractor stringExtractor(cu->getContext().getStringSection(),
420 false, 0);
421 return form_value.getAsCString(&stringExtractor);
422 }
423 return fail_value;
424 }
425
426 uint64_t
getAttributeValueAsUnsigned(const DWARFCompileUnit * cu,const uint16_t attr,uint64_t fail_value) const427 DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsigned(
428 const DWARFCompileUnit* cu,
429 const uint16_t attr,
430 uint64_t fail_value) const {
431 DWARFFormValue form_value;
432 if (getAttributeValue(cu, attr, form_value))
433 return form_value.getUnsigned();
434 return fail_value;
435 }
436
437 int64_t
getAttributeValueAsSigned(const DWARFCompileUnit * cu,const uint16_t attr,int64_t fail_value) const438 DWARFDebugInfoEntryMinimal::getAttributeValueAsSigned(
439 const DWARFCompileUnit* cu,
440 const uint16_t attr,
441 int64_t fail_value) const {
442 DWARFFormValue form_value;
443 if (getAttributeValue(cu, attr, form_value))
444 return form_value.getSigned();
445 return fail_value;
446 }
447
448 uint64_t
getAttributeValueAsReference(const DWARFCompileUnit * cu,const uint16_t attr,uint64_t fail_value) const449 DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
450 const DWARFCompileUnit* cu,
451 const uint16_t attr,
452 uint64_t fail_value) const {
453 DWARFFormValue form_value;
454 if (getAttributeValue(cu, attr, form_value))
455 return form_value.getReference(cu);
456 return fail_value;
457 }
458
getLowAndHighPC(const DWARFCompileUnit * CU,uint64_t & LowPC,uint64_t & HighPC) const459 bool DWARFDebugInfoEntryMinimal::getLowAndHighPC(const DWARFCompileUnit *CU,
460 uint64_t &LowPC, uint64_t &HighPC) const {
461 HighPC = -1ULL;
462 LowPC = getAttributeValueAsUnsigned(CU, DW_AT_low_pc, -1ULL);
463 if (LowPC != -1ULL)
464 HighPC = getAttributeValueAsUnsigned(CU, DW_AT_high_pc, -1ULL);
465 return (HighPC != -1ULL);
466 }
467
468 void
buildAddressRangeTable(const DWARFCompileUnit * CU,DWARFDebugAranges * DebugAranges) const469 DWARFDebugInfoEntryMinimal::buildAddressRangeTable(const DWARFCompileUnit *CU,
470 DWARFDebugAranges *DebugAranges)
471 const {
472 if (AbbrevDecl) {
473 if (isSubprogramDIE()) {
474 uint64_t LowPC, HighPC;
475 if (getLowAndHighPC(CU, LowPC, HighPC)) {
476 DebugAranges->appendRange(CU->getOffset(), LowPC, HighPC);
477 }
478 // FIXME: try to append ranges from .debug_ranges section.
479 }
480
481 const DWARFDebugInfoEntryMinimal *child = getFirstChild();
482 while (child) {
483 child->buildAddressRangeTable(CU, DebugAranges);
484 child = child->getSibling();
485 }
486 }
487 }
488
489 bool
addressRangeContainsAddress(const DWARFCompileUnit * CU,const uint64_t Address) const490 DWARFDebugInfoEntryMinimal::addressRangeContainsAddress(
491 const DWARFCompileUnit *CU, const uint64_t Address) const {
492 if (isNULL())
493 return false;
494 uint64_t LowPC, HighPC;
495 if (getLowAndHighPC(CU, LowPC, HighPC))
496 return (LowPC <= Address && Address <= HighPC);
497 // Try to get address ranges from .debug_ranges section.
498 uint32_t RangesOffset = getAttributeValueAsReference(CU, DW_AT_ranges, -1U);
499 if (RangesOffset != -1U) {
500 DWARFDebugRangeList RangeList;
501 if (CU->extractRangeList(RangesOffset, RangeList))
502 return RangeList.containsAddress(CU->getBaseAddress(), Address);
503 }
504 return false;
505 }
506
507 const char*
getSubroutineName(const DWARFCompileUnit * CU) const508 DWARFDebugInfoEntryMinimal::getSubroutineName(
509 const DWARFCompileUnit *CU) const {
510 if (!isSubroutineDIE())
511 return 0;
512 // Try to get mangled name if possible.
513 if (const char *name =
514 getAttributeValueAsString(CU, DW_AT_MIPS_linkage_name, 0))
515 return name;
516 if (const char *name = getAttributeValueAsString(CU, DW_AT_linkage_name, 0))
517 return name;
518 if (const char *name = getAttributeValueAsString(CU, DW_AT_name, 0))
519 return name;
520 // Try to get name from specification DIE.
521 uint32_t spec_ref =
522 getAttributeValueAsReference(CU, DW_AT_specification, -1U);
523 if (spec_ref != -1U) {
524 DWARFDebugInfoEntryMinimal spec_die;
525 if (spec_die.extract(CU, &spec_ref)) {
526 if (const char *name = spec_die.getSubroutineName(CU))
527 return name;
528 }
529 }
530 // Try to get name from abstract origin DIE.
531 uint32_t abs_origin_ref =
532 getAttributeValueAsReference(CU, DW_AT_abstract_origin, -1U);
533 if (abs_origin_ref != -1U) {
534 DWARFDebugInfoEntryMinimal abs_origin_die;
535 if (abs_origin_die.extract(CU, &abs_origin_ref)) {
536 if (const char *name = abs_origin_die.getSubroutineName(CU))
537 return name;
538 }
539 }
540 return 0;
541 }
542
getCallerFrame(const DWARFCompileUnit * CU,uint32_t & CallFile,uint32_t & CallLine,uint32_t & CallColumn) const543 void DWARFDebugInfoEntryMinimal::getCallerFrame(
544 const DWARFCompileUnit *CU, uint32_t &CallFile, uint32_t &CallLine,
545 uint32_t &CallColumn) const {
546 CallFile = getAttributeValueAsUnsigned(CU, DW_AT_call_file, 0);
547 CallLine = getAttributeValueAsUnsigned(CU, DW_AT_call_line, 0);
548 CallColumn = getAttributeValueAsUnsigned(CU, DW_AT_call_column, 0);
549 }
550
551 DWARFDebugInfoEntryMinimal::InlinedChain
getInlinedChainForAddress(const DWARFCompileUnit * CU,const uint64_t Address) const552 DWARFDebugInfoEntryMinimal::getInlinedChainForAddress(
553 const DWARFCompileUnit *CU, const uint64_t Address) const {
554 DWARFDebugInfoEntryMinimal::InlinedChain InlinedChain;
555 if (isNULL())
556 return InlinedChain;
557 for (const DWARFDebugInfoEntryMinimal *DIE = this; DIE; ) {
558 // Append current DIE to inlined chain only if it has correct tag
559 // (e.g. it is not a lexical block).
560 if (DIE->isSubroutineDIE()) {
561 InlinedChain.push_back(*DIE);
562 }
563 // Try to get child which also contains provided address.
564 const DWARFDebugInfoEntryMinimal *Child = DIE->getFirstChild();
565 while (Child) {
566 if (Child->addressRangeContainsAddress(CU, Address)) {
567 // Assume there is only one such child.
568 break;
569 }
570 Child = Child->getSibling();
571 }
572 DIE = Child;
573 }
574 // Reverse the obtained chain to make the root of inlined chain last.
575 std::reverse(InlinedChain.begin(), InlinedChain.end());
576 return InlinedChain;
577 }
578