1 //===-- DWARFFormValue.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 "SyntaxHighlighting.h"
11 #include "llvm/ADT/ArrayRef.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
14 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
15 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
16 #include "llvm/Support/Debug.h"
17 #include "llvm/Support/Dwarf.h"
18 #include "llvm/Support/Format.h"
19 #include "llvm/Support/raw_ostream.h"
20 #include <cassert>
21 #include <climits>
22 using namespace llvm;
23 using namespace dwarf;
24 using namespace syntax;
25
26 namespace {
getRefAddrSize(uint8_t AddrSize,uint16_t Version)27 uint8_t getRefAddrSize(uint8_t AddrSize, uint16_t Version) {
28 // FIXME: Support DWARF64.
29 return (Version == 2) ? AddrSize : 4;
30 }
31
32 template <uint8_t AddrSize, uint8_t RefAddrSize>
makeFixedFormSizesArrayRef()33 ArrayRef<uint8_t> makeFixedFormSizesArrayRef() {
34 static const uint8_t sizes[] = {
35 0, // 0x00 unused
36 AddrSize, // 0x01 DW_FORM_addr
37 0, // 0x02 unused
38 0, // 0x03 DW_FORM_block2
39 0, // 0x04 DW_FORM_block4
40 2, // 0x05 DW_FORM_data2
41 4, // 0x06 DW_FORM_data4
42 8, // 0x07 DW_FORM_data8
43 0, // 0x08 DW_FORM_string
44 0, // 0x09 DW_FORM_block
45 0, // 0x0a DW_FORM_block1
46 1, // 0x0b DW_FORM_data1
47 1, // 0x0c DW_FORM_flag
48 0, // 0x0d DW_FORM_sdata
49 4, // 0x0e DW_FORM_strp
50 0, // 0x0f DW_FORM_udata
51 RefAddrSize, // 0x10 DW_FORM_ref_addr
52 1, // 0x11 DW_FORM_ref1
53 2, // 0x12 DW_FORM_ref2
54 4, // 0x13 DW_FORM_ref4
55 8, // 0x14 DW_FORM_ref8
56 0, // 0x15 DW_FORM_ref_udata
57 0, // 0x16 DW_FORM_indirect
58 4, // 0x17 DW_FORM_sec_offset
59 0, // 0x18 DW_FORM_exprloc
60 0, // 0x19 DW_FORM_flag_present
61 };
62 return makeArrayRef(sizes);
63 }
64 }
65
getFixedFormSizes(uint8_t AddrSize,uint16_t Version)66 ArrayRef<uint8_t> DWARFFormValue::getFixedFormSizes(uint8_t AddrSize,
67 uint16_t Version) {
68 uint8_t RefAddrSize = getRefAddrSize(AddrSize, Version);
69 if (AddrSize == 4 && RefAddrSize == 4)
70 return makeFixedFormSizesArrayRef<4, 4>();
71 if (AddrSize == 4 && RefAddrSize == 8)
72 return makeFixedFormSizesArrayRef<4, 8>();
73 if (AddrSize == 8 && RefAddrSize == 4)
74 return makeFixedFormSizesArrayRef<8, 4>();
75 if (AddrSize == 8 && RefAddrSize == 8)
76 return makeFixedFormSizesArrayRef<8, 8>();
77 return None;
78 }
79
80 static const DWARFFormValue::FormClass DWARF4FormClasses[] = {
81 DWARFFormValue::FC_Unknown, // 0x0
82 DWARFFormValue::FC_Address, // 0x01 DW_FORM_addr
83 DWARFFormValue::FC_Unknown, // 0x02 unused
84 DWARFFormValue::FC_Block, // 0x03 DW_FORM_block2
85 DWARFFormValue::FC_Block, // 0x04 DW_FORM_block4
86 DWARFFormValue::FC_Constant, // 0x05 DW_FORM_data2
87 // --- These can be FC_SectionOffset in DWARF3 and below:
88 DWARFFormValue::FC_Constant, // 0x06 DW_FORM_data4
89 DWARFFormValue::FC_Constant, // 0x07 DW_FORM_data8
90 // ---
91 DWARFFormValue::FC_String, // 0x08 DW_FORM_string
92 DWARFFormValue::FC_Block, // 0x09 DW_FORM_block
93 DWARFFormValue::FC_Block, // 0x0a DW_FORM_block1
94 DWARFFormValue::FC_Constant, // 0x0b DW_FORM_data1
95 DWARFFormValue::FC_Flag, // 0x0c DW_FORM_flag
96 DWARFFormValue::FC_Constant, // 0x0d DW_FORM_sdata
97 DWARFFormValue::FC_String, // 0x0e DW_FORM_strp
98 DWARFFormValue::FC_Constant, // 0x0f DW_FORM_udata
99 DWARFFormValue::FC_Reference, // 0x10 DW_FORM_ref_addr
100 DWARFFormValue::FC_Reference, // 0x11 DW_FORM_ref1
101 DWARFFormValue::FC_Reference, // 0x12 DW_FORM_ref2
102 DWARFFormValue::FC_Reference, // 0x13 DW_FORM_ref4
103 DWARFFormValue::FC_Reference, // 0x14 DW_FORM_ref8
104 DWARFFormValue::FC_Reference, // 0x15 DW_FORM_ref_udata
105 DWARFFormValue::FC_Indirect, // 0x16 DW_FORM_indirect
106 DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset
107 DWARFFormValue::FC_Exprloc, // 0x18 DW_FORM_exprloc
108 DWARFFormValue::FC_Flag, // 0x19 DW_FORM_flag_present
109 };
110
isFormClass(DWARFFormValue::FormClass FC) const111 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
112 // First, check DWARF4 form classes.
113 if (Form < ArrayRef<FormClass>(DWARF4FormClasses).size() &&
114 DWARF4FormClasses[Form] == FC)
115 return true;
116 // Check DW_FORM_ref_sig8 from DWARF4.
117 if (Form == DW_FORM_ref_sig8)
118 return (FC == FC_Reference);
119 // Check for some DWARF5 forms.
120 if (Form == DW_FORM_GNU_addr_index)
121 return (FC == FC_Address);
122 if (Form == DW_FORM_GNU_str_index)
123 return (FC == FC_String);
124 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset.
125 // Don't check for DWARF version here, as some producers may still do this
126 // by mistake.
127 if ((Form == DW_FORM_data4 || Form == DW_FORM_data8) &&
128 FC == FC_SectionOffset)
129 return true;
130 return false;
131 }
132
extractValue(DataExtractor data,uint32_t * offset_ptr,const DWARFUnit * cu)133 bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
134 const DWARFUnit *cu) {
135 bool indirect = false;
136 bool is_block = false;
137 Value.data = nullptr;
138 // Read the value for the form into value and follow and DW_FORM_indirect
139 // instances we run into
140 do {
141 indirect = false;
142 switch (Form) {
143 case DW_FORM_addr:
144 case DW_FORM_ref_addr: {
145 if (!cu)
146 return false;
147 uint16_t AddrSize =
148 (Form == DW_FORM_addr)
149 ? cu->getAddressByteSize()
150 : getRefAddrSize(cu->getAddressByteSize(), cu->getVersion());
151 RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr);
152 if (AI != cu->getRelocMap()->end()) {
153 const std::pair<uint8_t, int64_t> &R = AI->second;
154 Value.uval = data.getUnsigned(offset_ptr, AddrSize) + R.second;
155 } else
156 Value.uval = data.getUnsigned(offset_ptr, AddrSize);
157 break;
158 }
159 case DW_FORM_exprloc:
160 case DW_FORM_block:
161 Value.uval = data.getULEB128(offset_ptr);
162 is_block = true;
163 break;
164 case DW_FORM_block1:
165 Value.uval = data.getU8(offset_ptr);
166 is_block = true;
167 break;
168 case DW_FORM_block2:
169 Value.uval = data.getU16(offset_ptr);
170 is_block = true;
171 break;
172 case DW_FORM_block4:
173 Value.uval = data.getU32(offset_ptr);
174 is_block = true;
175 break;
176 case DW_FORM_data1:
177 case DW_FORM_ref1:
178 case DW_FORM_flag:
179 Value.uval = data.getU8(offset_ptr);
180 break;
181 case DW_FORM_data2:
182 case DW_FORM_ref2:
183 Value.uval = data.getU16(offset_ptr);
184 break;
185 case DW_FORM_data4:
186 case DW_FORM_ref4: {
187 Value.uval = data.getU32(offset_ptr);
188 if (!cu)
189 break;
190 RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
191 if (AI != cu->getRelocMap()->end())
192 Value.uval += AI->second.second;
193 break;
194 }
195 case DW_FORM_data8:
196 case DW_FORM_ref8:
197 Value.uval = data.getU64(offset_ptr);
198 break;
199 case DW_FORM_sdata:
200 Value.sval = data.getSLEB128(offset_ptr);
201 break;
202 case DW_FORM_strp: {
203 Value.uval = data.getU32(offset_ptr);
204 if (!cu)
205 break;
206 RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
207 if (AI != cu->getRelocMap()->end())
208 Value.uval += AI->second.second;
209 break;
210 }
211 case DW_FORM_udata:
212 case DW_FORM_ref_udata:
213 Value.uval = data.getULEB128(offset_ptr);
214 break;
215 case DW_FORM_string:
216 Value.cstr = data.getCStr(offset_ptr);
217 break;
218 case DW_FORM_indirect:
219 Form = data.getULEB128(offset_ptr);
220 indirect = true;
221 break;
222 case DW_FORM_sec_offset: {
223 // FIXME: This is 64-bit for DWARF64.
224 Value.uval = data.getU32(offset_ptr);
225 if (!cu)
226 break;
227 RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
228 if (AI != cu->getRelocMap()->end())
229 Value.uval += AI->second.second;
230 break;
231 }
232 case DW_FORM_flag_present:
233 Value.uval = 1;
234 break;
235 case DW_FORM_ref_sig8:
236 Value.uval = data.getU64(offset_ptr);
237 break;
238 case DW_FORM_GNU_addr_index:
239 case DW_FORM_GNU_str_index:
240 Value.uval = data.getULEB128(offset_ptr);
241 break;
242 default:
243 return false;
244 }
245 } while (indirect);
246
247 if (is_block) {
248 StringRef str = data.getData().substr(*offset_ptr, Value.uval);
249 Value.data = nullptr;
250 if (!str.empty()) {
251 Value.data = reinterpret_cast<const uint8_t *>(str.data());
252 *offset_ptr += Value.uval;
253 }
254 }
255
256 return true;
257 }
258
259 bool
skipValue(DataExtractor debug_info_data,uint32_t * offset_ptr,const DWARFUnit * cu) const260 DWARFFormValue::skipValue(DataExtractor debug_info_data, uint32_t* offset_ptr,
261 const DWARFUnit *cu) const {
262 return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, cu);
263 }
264
265 bool
skipValue(uint16_t form,DataExtractor debug_info_data,uint32_t * offset_ptr,const DWARFUnit * cu)266 DWARFFormValue::skipValue(uint16_t form, DataExtractor debug_info_data,
267 uint32_t *offset_ptr, const DWARFUnit *cu) {
268 bool indirect = false;
269 do {
270 switch (form) {
271 // Blocks if inlined data that have a length field and the data bytes
272 // inlined in the .debug_info
273 case DW_FORM_exprloc:
274 case DW_FORM_block: {
275 uint64_t size = debug_info_data.getULEB128(offset_ptr);
276 *offset_ptr += size;
277 return true;
278 }
279 case DW_FORM_block1: {
280 uint8_t size = debug_info_data.getU8(offset_ptr);
281 *offset_ptr += size;
282 return true;
283 }
284 case DW_FORM_block2: {
285 uint16_t size = debug_info_data.getU16(offset_ptr);
286 *offset_ptr += size;
287 return true;
288 }
289 case DW_FORM_block4: {
290 uint32_t size = debug_info_data.getU32(offset_ptr);
291 *offset_ptr += size;
292 return true;
293 }
294
295 // Inlined NULL terminated C-strings
296 case DW_FORM_string:
297 debug_info_data.getCStr(offset_ptr);
298 return true;
299
300 // Compile unit address sized values
301 case DW_FORM_addr:
302 *offset_ptr += cu->getAddressByteSize();
303 return true;
304 case DW_FORM_ref_addr:
305 *offset_ptr += getRefAddrSize(cu->getAddressByteSize(), cu->getVersion());
306 return true;
307
308 // 0 byte values - implied from the form.
309 case DW_FORM_flag_present:
310 return true;
311
312 // 1 byte values
313 case DW_FORM_data1:
314 case DW_FORM_flag:
315 case DW_FORM_ref1:
316 *offset_ptr += 1;
317 return true;
318
319 // 2 byte values
320 case DW_FORM_data2:
321 case DW_FORM_ref2:
322 *offset_ptr += 2;
323 return true;
324
325 // 4 byte values
326 case DW_FORM_strp:
327 case DW_FORM_data4:
328 case DW_FORM_ref4:
329 *offset_ptr += 4;
330 return true;
331
332 // 8 byte values
333 case DW_FORM_data8:
334 case DW_FORM_ref8:
335 case DW_FORM_ref_sig8:
336 *offset_ptr += 8;
337 return true;
338
339 // signed or unsigned LEB 128 values
340 // case DW_FORM_APPLE_db_str:
341 case DW_FORM_sdata:
342 case DW_FORM_udata:
343 case DW_FORM_ref_udata:
344 case DW_FORM_GNU_str_index:
345 case DW_FORM_GNU_addr_index:
346 debug_info_data.getULEB128(offset_ptr);
347 return true;
348
349 case DW_FORM_indirect:
350 indirect = true;
351 form = debug_info_data.getULEB128(offset_ptr);
352 break;
353
354 // FIXME: 4 for DWARF32, 8 for DWARF64.
355 case DW_FORM_sec_offset:
356 *offset_ptr += 4;
357 return true;
358
359 default:
360 return false;
361 }
362 } while (indirect);
363 return true;
364 }
365
366 void
dump(raw_ostream & OS,const DWARFUnit * cu) const367 DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
368 uint64_t uvalue = Value.uval;
369 bool cu_relative_offset = false;
370
371 switch (Form) {
372 case DW_FORM_addr: OS << format("0x%016" PRIx64, uvalue); break;
373 case DW_FORM_GNU_addr_index: {
374 OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
375 uint64_t Address;
376 if (cu->getAddrOffsetSectionItem(uvalue, Address))
377 OS << format("0x%016" PRIx64, Address);
378 else
379 OS << "<no .debug_addr section>";
380 break;
381 }
382 case DW_FORM_flag_present: OS << "true"; break;
383 case DW_FORM_flag:
384 case DW_FORM_data1: OS << format("0x%02x", (uint8_t)uvalue); break;
385 case DW_FORM_data2: OS << format("0x%04x", (uint16_t)uvalue); break;
386 case DW_FORM_data4: OS << format("0x%08x", (uint32_t)uvalue); break;
387 case DW_FORM_ref_sig8:
388 case DW_FORM_data8: OS << format("0x%016" PRIx64, uvalue); break;
389 case DW_FORM_string:
390 OS << '"';
391 OS.write_escaped(Value.cstr);
392 OS << '"';
393 break;
394 case DW_FORM_exprloc:
395 case DW_FORM_block:
396 case DW_FORM_block1:
397 case DW_FORM_block2:
398 case DW_FORM_block4:
399 if (uvalue > 0) {
400 switch (Form) {
401 case DW_FORM_exprloc:
402 case DW_FORM_block: OS << format("<0x%" PRIx64 "> ", uvalue); break;
403 case DW_FORM_block1: OS << format("<0x%2.2x> ", (uint8_t)uvalue); break;
404 case DW_FORM_block2: OS << format("<0x%4.4x> ", (uint16_t)uvalue); break;
405 case DW_FORM_block4: OS << format("<0x%8.8x> ", (uint32_t)uvalue); break;
406 default: break;
407 }
408
409 const uint8_t* data_ptr = Value.data;
410 if (data_ptr) {
411 // uvalue contains size of block
412 const uint8_t* end_data_ptr = data_ptr + uvalue;
413 while (data_ptr < end_data_ptr) {
414 OS << format("%2.2x ", *data_ptr);
415 ++data_ptr;
416 }
417 }
418 else
419 OS << "NULL";
420 }
421 break;
422
423 case DW_FORM_sdata: OS << Value.sval; break;
424 case DW_FORM_udata: OS << Value.uval; break;
425 case DW_FORM_strp: {
426 OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
427 Optional<const char *> DbgStr = getAsCString(cu);
428 if (DbgStr.hasValue()) {
429 raw_ostream &COS = WithColor(OS, syntax::String);
430 COS << '"';
431 COS.write_escaped(DbgStr.getValue());
432 COS << '"';
433 }
434 break;
435 }
436 case DW_FORM_GNU_str_index: {
437 OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
438 Optional<const char *> DbgStr = getAsCString(cu);
439 if (DbgStr.hasValue()) {
440 raw_ostream &COS = WithColor(OS, syntax::String);
441 COS << '"';
442 COS.write_escaped(DbgStr.getValue());
443 COS << '"';
444 }
445 break;
446 }
447 case DW_FORM_ref_addr:
448 OS << format("0x%016" PRIx64, uvalue);
449 break;
450 case DW_FORM_ref1:
451 cu_relative_offset = true;
452 OS << format("cu + 0x%2.2x", (uint8_t)uvalue);
453 break;
454 case DW_FORM_ref2:
455 cu_relative_offset = true;
456 OS << format("cu + 0x%4.4x", (uint16_t)uvalue);
457 break;
458 case DW_FORM_ref4:
459 cu_relative_offset = true;
460 OS << format("cu + 0x%4.4x", (uint32_t)uvalue);
461 break;
462 case DW_FORM_ref8:
463 cu_relative_offset = true;
464 OS << format("cu + 0x%8.8" PRIx64, uvalue);
465 break;
466 case DW_FORM_ref_udata:
467 cu_relative_offset = true;
468 OS << format("cu + 0x%" PRIx64, uvalue);
469 break;
470
471 // All DW_FORM_indirect attributes should be resolved prior to calling
472 // this function
473 case DW_FORM_indirect:
474 OS << "DW_FORM_indirect";
475 break;
476
477 // Should be formatted to 64-bit for DWARF64.
478 case DW_FORM_sec_offset:
479 OS << format("0x%08x", (uint32_t)uvalue);
480 break;
481
482 default:
483 OS << format("DW_FORM(0x%4.4x)", Form);
484 break;
485 }
486
487 if (cu_relative_offset) {
488 OS << " => {";
489 WithColor(OS, syntax::Address).get()
490 << format("0x%8.8" PRIx64, uvalue + (cu ? cu->getOffset() : 0));
491 OS << "}";
492 }
493 }
494
getAsCString(const DWARFUnit * U) const495 Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {
496 if (!isFormClass(FC_String))
497 return None;
498 if (Form == DW_FORM_string)
499 return Value.cstr;
500 if (!U)
501 return None;
502 uint32_t Offset = Value.uval;
503 if (Form == DW_FORM_GNU_str_index) {
504 uint32_t StrOffset;
505 if (!U->getStringOffsetSectionItem(Offset, StrOffset))
506 return None;
507 Offset = StrOffset;
508 }
509 if (const char *Str = U->getStringExtractor().getCStr(&Offset)) {
510 return Str;
511 }
512 return None;
513 }
514
getAsAddress(const DWARFUnit * U) const515 Optional<uint64_t> DWARFFormValue::getAsAddress(const DWARFUnit *U) const {
516 if (!isFormClass(FC_Address))
517 return None;
518 if (Form == DW_FORM_GNU_addr_index) {
519 uint32_t Index = Value.uval;
520 uint64_t Result;
521 if (!U || !U->getAddrOffsetSectionItem(Index, Result))
522 return None;
523 return Result;
524 }
525 return Value.uval;
526 }
527
getAsReference(const DWARFUnit * U) const528 Optional<uint64_t> DWARFFormValue::getAsReference(const DWARFUnit *U) const {
529 if (!isFormClass(FC_Reference))
530 return None;
531 switch (Form) {
532 case DW_FORM_ref1:
533 case DW_FORM_ref2:
534 case DW_FORM_ref4:
535 case DW_FORM_ref8:
536 case DW_FORM_ref_udata:
537 if (!U)
538 return None;
539 return Value.uval + U->getOffset();
540 case DW_FORM_ref_addr:
541 return Value.uval;
542 // FIXME: Add proper support for DW_FORM_ref_sig8
543 default:
544 return Value.uval;
545 }
546 }
547
getAsSectionOffset() const548 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const {
549 if (!isFormClass(FC_SectionOffset))
550 return None;
551 return Value.uval;
552 }
553
getAsUnsignedConstant() const554 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const {
555 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag))
556 || Form == DW_FORM_sdata)
557 return None;
558 return Value.uval;
559 }
560
getAsSignedConstant() const561 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const {
562 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) ||
563 (Form == DW_FORM_udata && uint64_t(LLONG_MAX) < Value.uval))
564 return None;
565 switch (Form) {
566 case DW_FORM_data4:
567 return int32_t(Value.uval);
568 case DW_FORM_data2:
569 return int16_t(Value.uval);
570 case DW_FORM_data1:
571 return int8_t(Value.uval);
572 case DW_FORM_sdata:
573 case DW_FORM_data8:
574 default:
575 return Value.sval;
576 }
577 }
578
getAsBlock() const579 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const {
580 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc))
581 return None;
582 return ArrayRef<uint8_t>(Value.data, Value.uval);
583 }
584
585