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/Debug.h"
16 #include "llvm/Support/Dwarf.h"
17 #include "llvm/Support/Format.h"
18 #include "llvm/Support/raw_ostream.h"
19 using namespace llvm;
20 using namespace dwarf;
21
dump(raw_ostream & OS,const DWARFCompileUnit * cu,unsigned recurseDepth,unsigned indent) const22 void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS,
23 const DWARFCompileUnit *cu,
24 unsigned recurseDepth,
25 unsigned indent) const {
26 DataExtractor debug_info_data = cu->getDebugInfoExtractor();
27 uint32_t offset = Offset;
28
29 if (debug_info_data.isValidOffset(offset)) {
30 uint32_t abbrCode = debug_info_data.getULEB128(&offset);
31
32 OS << format("\n0x%8.8x: ", Offset);
33 if (abbrCode) {
34 if (AbbrevDecl) {
35 const char *tagString = TagString(getTag());
36 if (tagString)
37 OS.indent(indent) << tagString;
38 else
39 OS.indent(indent) << format("DW_TAG_Unknown_%x", getTag());
40 OS << format(" [%u] %c\n", abbrCode,
41 AbbrevDecl->hasChildren() ? '*' : ' ');
42
43 // Dump all data in the DIE for the attributes.
44 const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
45 for (uint32_t i = 0; i != numAttributes; ++i) {
46 uint16_t attr = AbbrevDecl->getAttrByIndex(i);
47 uint16_t form = AbbrevDecl->getFormByIndex(i);
48 dumpAttribute(OS, cu, &offset, attr, form, indent);
49 }
50
51 const DWARFDebugInfoEntryMinimal *child = getFirstChild();
52 if (recurseDepth > 0 && child) {
53 while (child) {
54 child->dump(OS, cu, recurseDepth-1, indent+2);
55 child = child->getSibling();
56 }
57 }
58 } else {
59 OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
60 << abbrCode << '\n';
61 }
62 } else {
63 OS.indent(indent) << "NULL\n";
64 }
65 }
66 }
67
dumpAttribute(raw_ostream & OS,const DWARFCompileUnit * cu,uint32_t * offset_ptr,uint16_t attr,uint16_t form,unsigned indent) const68 void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
69 const DWARFCompileUnit *cu,
70 uint32_t* offset_ptr,
71 uint16_t attr,
72 uint16_t form,
73 unsigned indent) const {
74 OS << format("0x%8.8x: ", *offset_ptr);
75 OS.indent(indent+2);
76 const char *attrString = AttributeString(attr);
77 if (attrString)
78 OS << attrString;
79 else
80 OS << format("DW_AT_Unknown_%x", attr);
81 const char *formString = FormEncodingString(form);
82 if (formString)
83 OS << " [" << formString << ']';
84 else
85 OS << format(" [DW_FORM_Unknown_%x]", form);
86
87 DWARFFormValue formValue(form);
88
89 if (!formValue.extractValue(cu->getDebugInfoExtractor(), offset_ptr, cu))
90 return;
91
92 OS << "\t(";
93 formValue.dump(OS, cu);
94 OS << ")\n";
95 }
96
extractFast(const DWARFCompileUnit * cu,const uint8_t * fixed_form_sizes,uint32_t * offset_ptr)97 bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFCompileUnit *cu,
98 const uint8_t *fixed_form_sizes,
99 uint32_t *offset_ptr) {
100 Offset = *offset_ptr;
101
102 DataExtractor debug_info_data = cu->getDebugInfoExtractor();
103 uint64_t abbrCode = debug_info_data.getULEB128(offset_ptr);
104
105 assert(fixed_form_sizes); // For best performance this should be specified!
106
107 if (abbrCode) {
108 uint32_t offset = *offset_ptr;
109
110 AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
111
112 // Skip all data in the .debug_info for the attributes
113 const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
114 uint32_t i;
115 uint16_t form;
116 for (i=0; i<numAttributes; ++i) {
117
118 form = AbbrevDecl->getFormByIndex(i);
119
120 // FIXME: Currently we're checking if this is less than the last
121 // entry in the fixed_form_sizes table, but this should be changed
122 // to use dynamic dispatch.
123 const uint8_t fixed_skip_size = (form < DW_FORM_ref_sig8) ?
124 fixed_form_sizes[form] : 0;
125 if (fixed_skip_size)
126 offset += fixed_skip_size;
127 else {
128 bool form_is_indirect = false;
129 do {
130 form_is_indirect = false;
131 uint32_t form_size = 0;
132 switch (form) {
133 // Blocks if inlined data that have a length field and the data bytes
134 // inlined in the .debug_info.
135 case DW_FORM_exprloc:
136 case DW_FORM_block:
137 form_size = debug_info_data.getULEB128(&offset);
138 break;
139 case DW_FORM_block1:
140 form_size = debug_info_data.getU8(&offset);
141 break;
142 case DW_FORM_block2:
143 form_size = debug_info_data.getU16(&offset);
144 break;
145 case DW_FORM_block4:
146 form_size = debug_info_data.getU32(&offset);
147 break;
148
149 // Inlined NULL terminated C-strings
150 case DW_FORM_string:
151 debug_info_data.getCStr(&offset);
152 break;
153
154 // Compile unit address sized values
155 case DW_FORM_addr:
156 case DW_FORM_ref_addr:
157 form_size = cu->getAddressByteSize();
158 break;
159
160 // 0 sized form.
161 case DW_FORM_flag_present:
162 form_size = 0;
163 break;
164
165 // 1 byte values
166 case DW_FORM_data1:
167 case DW_FORM_flag:
168 case DW_FORM_ref1:
169 form_size = 1;
170 break;
171
172 // 2 byte values
173 case DW_FORM_data2:
174 case DW_FORM_ref2:
175 form_size = 2;
176 break;
177
178 // 4 byte values
179 case DW_FORM_strp:
180 case DW_FORM_data4:
181 case DW_FORM_ref4:
182 form_size = 4;
183 break;
184
185 // 8 byte values
186 case DW_FORM_data8:
187 case DW_FORM_ref8:
188 case DW_FORM_ref_sig8:
189 form_size = 8;
190 break;
191
192 // signed or unsigned LEB 128 values
193 case DW_FORM_sdata:
194 case DW_FORM_udata:
195 case DW_FORM_ref_udata:
196 case DW_FORM_GNU_str_index:
197 case DW_FORM_GNU_addr_index:
198 debug_info_data.getULEB128(&offset);
199 break;
200
201 case DW_FORM_indirect:
202 form_is_indirect = true;
203 form = debug_info_data.getULEB128(&offset);
204 break;
205
206 // FIXME: 64-bit for DWARF64
207 case DW_FORM_sec_offset:
208 debug_info_data.getU32(offset_ptr);
209 break;
210
211 default:
212 *offset_ptr = Offset;
213 return false;
214 }
215 offset += form_size;
216 } while (form_is_indirect);
217 }
218 }
219 *offset_ptr = offset;
220 return true;
221 } else {
222 AbbrevDecl = NULL;
223 return true; // NULL debug tag entry
224 }
225 }
226
227 bool
extract(const DWARFCompileUnit * cu,uint32_t * offset_ptr)228 DWARFDebugInfoEntryMinimal::extract(const DWARFCompileUnit *cu,
229 uint32_t *offset_ptr) {
230 DataExtractor debug_info_data = cu->getDebugInfoExtractor();
231 const uint32_t cu_end_offset = cu->getNextCompileUnitOffset();
232 const uint8_t cu_addr_size = cu->getAddressByteSize();
233 uint32_t offset = *offset_ptr;
234 if ((offset < cu_end_offset) && debug_info_data.isValidOffset(offset)) {
235 Offset = offset;
236
237 uint64_t abbrCode = debug_info_data.getULEB128(&offset);
238
239 if (abbrCode) {
240 AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
241
242 if (AbbrevDecl) {
243 uint16_t tag = AbbrevDecl->getTag();
244
245 bool isCompileUnitTag = tag == DW_TAG_compile_unit;
246 if(cu && isCompileUnitTag)
247 const_cast<DWARFCompileUnit*>(cu)->setBaseAddress(0);
248
249 // Skip all data in the .debug_info for the attributes
250 const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
251 for (uint32_t i = 0; i != numAttributes; ++i) {
252 uint16_t attr = AbbrevDecl->getAttrByIndex(i);
253 uint16_t form = AbbrevDecl->getFormByIndex(i);
254
255 if (isCompileUnitTag &&
256 ((attr == DW_AT_entry_pc) || (attr == DW_AT_low_pc))) {
257 DWARFFormValue form_value(form);
258 if (form_value.extractValue(debug_info_data, &offset, cu)) {
259 if (attr == DW_AT_low_pc || attr == DW_AT_entry_pc)
260 const_cast<DWARFCompileUnit*>(cu)
261 ->setBaseAddress(form_value.getUnsigned());
262 }
263 } else {
264 bool form_is_indirect = false;
265 do {
266 form_is_indirect = false;
267 register uint32_t form_size = 0;
268 switch (form) {
269 // Blocks if inlined data that have a length field and the data
270 // bytes // inlined in the .debug_info
271 case DW_FORM_exprloc:
272 case DW_FORM_block:
273 form_size = debug_info_data.getULEB128(&offset);
274 break;
275 case DW_FORM_block1:
276 form_size = debug_info_data.getU8(&offset);
277 break;
278 case DW_FORM_block2:
279 form_size = debug_info_data.getU16(&offset);
280 break;
281 case DW_FORM_block4:
282 form_size = debug_info_data.getU32(&offset);
283 break;
284
285 // Inlined NULL terminated C-strings
286 case DW_FORM_string:
287 debug_info_data.getCStr(&offset);
288 break;
289
290 // Compile unit address sized values
291 case DW_FORM_addr:
292 case DW_FORM_ref_addr:
293 form_size = cu_addr_size;
294 break;
295
296 // 0 byte value
297 case DW_FORM_flag_present:
298 form_size = 0;
299 break;
300
301 // 1 byte values
302 case DW_FORM_data1:
303 case DW_FORM_flag:
304 case DW_FORM_ref1:
305 form_size = 1;
306 break;
307
308 // 2 byte values
309 case DW_FORM_data2:
310 case DW_FORM_ref2:
311 form_size = 2;
312 break;
313
314 // 4 byte values
315 case DW_FORM_strp:
316 form_size = 4;
317 break;
318
319 case DW_FORM_data4:
320 case DW_FORM_ref4:
321 form_size = 4;
322 break;
323
324 // 8 byte values
325 case DW_FORM_data8:
326 case DW_FORM_ref8:
327 case DW_FORM_ref_sig8:
328 form_size = 8;
329 break;
330
331 // signed or unsigned LEB 128 values
332 case DW_FORM_sdata:
333 case DW_FORM_udata:
334 case DW_FORM_ref_udata:
335 case DW_FORM_GNU_str_index:
336 case DW_FORM_GNU_addr_index:
337 debug_info_data.getULEB128(&offset);
338 break;
339
340 case DW_FORM_indirect:
341 form = debug_info_data.getULEB128(&offset);
342 form_is_indirect = true;
343 break;
344
345 // FIXME: 64-bit for DWARF64.
346 case DW_FORM_sec_offset:
347 debug_info_data.getU32(offset_ptr);
348 break;
349
350 default:
351 *offset_ptr = offset;
352 return false;
353 }
354
355 offset += form_size;
356 } while (form_is_indirect);
357 }
358 }
359 *offset_ptr = offset;
360 return true;
361 }
362 } else {
363 AbbrevDecl = NULL;
364 *offset_ptr = offset;
365 return true; // NULL debug tag entry
366 }
367 }
368
369 return false;
370 }
371
isSubprogramDIE() const372 bool DWARFDebugInfoEntryMinimal::isSubprogramDIE() const {
373 return getTag() == DW_TAG_subprogram;
374 }
375
isSubroutineDIE() const376 bool DWARFDebugInfoEntryMinimal::isSubroutineDIE() const {
377 uint32_t Tag = getTag();
378 return Tag == DW_TAG_subprogram ||
379 Tag == DW_TAG_inlined_subroutine;
380 }
381
382 uint32_t
getAttributeValue(const DWARFCompileUnit * cu,const uint16_t attr,DWARFFormValue & form_value,uint32_t * end_attr_offset_ptr) const383 DWARFDebugInfoEntryMinimal::getAttributeValue(const DWARFCompileUnit *cu,
384 const uint16_t attr,
385 DWARFFormValue &form_value,
386 uint32_t *end_attr_offset_ptr)
387 const {
388 if (AbbrevDecl) {
389 uint32_t attr_idx = AbbrevDecl->findAttributeIndex(attr);
390
391 if (attr_idx != -1U) {
392 uint32_t offset = getOffset();
393
394 DataExtractor debug_info_data = cu->getDebugInfoExtractor();
395
396 // Skip the abbreviation code so we are at the data for the attributes
397 debug_info_data.getULEB128(&offset);
398
399 uint32_t idx = 0;
400 while (idx < attr_idx)
401 DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(idx++),
402 debug_info_data, &offset, cu);
403
404 const uint32_t attr_offset = offset;
405 form_value = DWARFFormValue(AbbrevDecl->getFormByIndex(idx));
406 if (form_value.extractValue(debug_info_data, &offset, cu)) {
407 if (end_attr_offset_ptr)
408 *end_attr_offset_ptr = offset;
409 return attr_offset;
410 }
411 }
412 }
413
414 return 0;
415 }
416
417 const char*
getAttributeValueAsString(const DWARFCompileUnit * cu,const uint16_t attr,const char * fail_value) const418 DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
419 const DWARFCompileUnit* cu,
420 const uint16_t attr,
421 const char* fail_value)
422 const {
423 DWARFFormValue form_value;
424 if (getAttributeValue(cu, attr, form_value)) {
425 DataExtractor stringExtractor(cu->getStringSection(), false, 0);
426 return form_value.getAsCString(&stringExtractor);
427 }
428 return fail_value;
429 }
430
431 uint64_t
getAttributeValueAsUnsigned(const DWARFCompileUnit * cu,const uint16_t attr,uint64_t fail_value) const432 DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsigned(
433 const DWARFCompileUnit* cu,
434 const uint16_t attr,
435 uint64_t fail_value) const {
436 DWARFFormValue form_value;
437 if (getAttributeValue(cu, attr, form_value))
438 return form_value.getUnsigned();
439 return fail_value;
440 }
441
442 int64_t
getAttributeValueAsSigned(const DWARFCompileUnit * cu,const uint16_t attr,int64_t fail_value) const443 DWARFDebugInfoEntryMinimal::getAttributeValueAsSigned(
444 const DWARFCompileUnit* cu,
445 const uint16_t attr,
446 int64_t fail_value) const {
447 DWARFFormValue form_value;
448 if (getAttributeValue(cu, attr, form_value))
449 return form_value.getSigned();
450 return fail_value;
451 }
452
453 uint64_t
getAttributeValueAsReference(const DWARFCompileUnit * cu,const uint16_t attr,uint64_t fail_value) const454 DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
455 const DWARFCompileUnit* cu,
456 const uint16_t attr,
457 uint64_t fail_value)
458 const {
459 DWARFFormValue form_value;
460 if (getAttributeValue(cu, attr, form_value))
461 return form_value.getReference(cu);
462 return fail_value;
463 }
464
getLowAndHighPC(const DWARFCompileUnit * CU,uint64_t & LowPC,uint64_t & HighPC) const465 bool DWARFDebugInfoEntryMinimal::getLowAndHighPC(const DWARFCompileUnit *CU,
466 uint64_t &LowPC,
467 uint64_t &HighPC) const {
468 HighPC = -1ULL;
469 LowPC = getAttributeValueAsUnsigned(CU, DW_AT_low_pc, -1ULL);
470 if (LowPC != -1ULL)
471 HighPC = getAttributeValueAsUnsigned(CU, DW_AT_high_pc, -1ULL);
472 return (HighPC != -1ULL);
473 }
474
475 void
buildAddressRangeTable(const DWARFCompileUnit * CU,DWARFDebugAranges * DebugAranges) const476 DWARFDebugInfoEntryMinimal::buildAddressRangeTable(const DWARFCompileUnit *CU,
477 DWARFDebugAranges *DebugAranges)
478 const {
479 if (AbbrevDecl) {
480 if (isSubprogramDIE()) {
481 uint64_t LowPC, HighPC;
482 if (getLowAndHighPC(CU, LowPC, HighPC)) {
483 DebugAranges->appendRange(CU->getOffset(), LowPC, HighPC);
484 }
485 // FIXME: try to append ranges from .debug_ranges section.
486 }
487
488 const DWARFDebugInfoEntryMinimal *child = getFirstChild();
489 while (child) {
490 child->buildAddressRangeTable(CU, DebugAranges);
491 child = child->getSibling();
492 }
493 }
494 }
495
496 bool
addressRangeContainsAddress(const DWARFCompileUnit * CU,const uint64_t Address) const497 DWARFDebugInfoEntryMinimal::addressRangeContainsAddress(
498 const DWARFCompileUnit *CU,
499 const uint64_t Address)
500 const {
501 if (isNULL())
502 return false;
503 uint64_t LowPC, HighPC;
504 if (getLowAndHighPC(CU, LowPC, HighPC))
505 return (LowPC <= Address && Address <= HighPC);
506 // Try to get address ranges from .debug_ranges section.
507 uint32_t RangesOffset = getAttributeValueAsReference(CU, DW_AT_ranges, -1U);
508 if (RangesOffset != -1U) {
509 DWARFDebugRangeList RangeList;
510 if (CU->extractRangeList(RangesOffset, RangeList))
511 return RangeList.containsAddress(CU->getBaseAddress(), Address);
512 }
513 return false;
514 }
515
516 const char*
getSubroutineName(const DWARFCompileUnit * CU) const517 DWARFDebugInfoEntryMinimal::getSubroutineName(const DWARFCompileUnit *CU)
518 const {
519 if (!isSubroutineDIE())
520 return 0;
521 // Try to get mangled name if possible.
522 if (const char *name =
523 getAttributeValueAsString(CU, DW_AT_MIPS_linkage_name, 0))
524 return name;
525 if (const char *name = getAttributeValueAsString(CU, DW_AT_linkage_name, 0))
526 return name;
527 if (const char *name = getAttributeValueAsString(CU, DW_AT_name, 0))
528 return name;
529 // Try to get name from specification DIE.
530 uint32_t spec_ref =
531 getAttributeValueAsReference(CU, DW_AT_specification, -1U);
532 if (spec_ref != -1U) {
533 DWARFDebugInfoEntryMinimal spec_die;
534 if (spec_die.extract(CU, &spec_ref)) {
535 if (const char *name = spec_die.getSubroutineName(CU))
536 return name;
537 }
538 }
539 // Try to get name from abstract origin DIE.
540 uint32_t abs_origin_ref =
541 getAttributeValueAsReference(CU, DW_AT_abstract_origin, -1U);
542 if (abs_origin_ref != -1U) {
543 DWARFDebugInfoEntryMinimal abs_origin_die;
544 if (abs_origin_die.extract(CU, &abs_origin_ref)) {
545 if (const char *name = abs_origin_die.getSubroutineName(CU))
546 return name;
547 }
548 }
549 return 0;
550 }
551
getCallerFrame(const DWARFCompileUnit * CU,uint32_t & CallFile,uint32_t & CallLine,uint32_t & CallColumn) const552 void DWARFDebugInfoEntryMinimal::getCallerFrame(const DWARFCompileUnit *CU,
553 uint32_t &CallFile,
554 uint32_t &CallLine,
555 uint32_t &CallColumn) const {
556 CallFile = getAttributeValueAsUnsigned(CU, DW_AT_call_file, 0);
557 CallLine = getAttributeValueAsUnsigned(CU, DW_AT_call_line, 0);
558 CallColumn = getAttributeValueAsUnsigned(CU, DW_AT_call_column, 0);
559 }
560
561 DWARFDebugInfoEntryMinimal::InlinedChain
getInlinedChainForAddress(const DWARFCompileUnit * CU,const uint64_t Address) const562 DWARFDebugInfoEntryMinimal::getInlinedChainForAddress(
563 const DWARFCompileUnit *CU,
564 const uint64_t Address)
565 const {
566 DWARFDebugInfoEntryMinimal::InlinedChain InlinedChain;
567 if (isNULL())
568 return InlinedChain;
569 for (const DWARFDebugInfoEntryMinimal *DIE = this; DIE; ) {
570 // Append current DIE to inlined chain only if it has correct tag
571 // (e.g. it is not a lexical block).
572 if (DIE->isSubroutineDIE()) {
573 InlinedChain.push_back(*DIE);
574 }
575 // Try to get child which also contains provided address.
576 const DWARFDebugInfoEntryMinimal *Child = DIE->getFirstChild();
577 while (Child) {
578 if (Child->addressRangeContainsAddress(CU, Address)) {
579 // Assume there is only one such child.
580 break;
581 }
582 Child = Child->getSibling();
583 }
584 DIE = Child;
585 }
586 // Reverse the obtained chain to make the root of inlined chain last.
587 std::reverse(InlinedChain.begin(), InlinedChain.end());
588 return InlinedChain;
589 }
590