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 <limits>
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 < makeArrayRef(DWARF4FormClasses).size() &&
114 DWARF4FormClasses[Form] == FC)
115 return true;
116 // Check more forms from DWARF4 and DWARF5 proposals.
117 switch (Form) {
118 case DW_FORM_ref_sig8:
119 case DW_FORM_GNU_ref_alt:
120 return (FC == FC_Reference);
121 case DW_FORM_GNU_addr_index:
122 return (FC == FC_Address);
123 case DW_FORM_GNU_str_index:
124 case DW_FORM_GNU_strp_alt:
125 return (FC == FC_String);
126 }
127 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset.
128 // Don't check for DWARF version here, as some producers may still do this
129 // by mistake.
130 return (Form == DW_FORM_data4 || Form == DW_FORM_data8) &&
131 FC == FC_SectionOffset;
132 }
133
extractValue(DataExtractor data,uint32_t * offset_ptr,const DWARFUnit * cu)134 bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
135 const DWARFUnit *cu) {
136 bool indirect = false;
137 bool is_block = false;
138 Value.data = nullptr;
139 // Read the value for the form into value and follow and DW_FORM_indirect
140 // instances we run into
141 do {
142 indirect = false;
143 switch (Form) {
144 case DW_FORM_addr:
145 case DW_FORM_ref_addr: {
146 if (!cu)
147 return false;
148 uint16_t AddrSize =
149 (Form == DW_FORM_addr)
150 ? cu->getAddressByteSize()
151 : getRefAddrSize(cu->getAddressByteSize(), cu->getVersion());
152 RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr);
153 if (AI != cu->getRelocMap()->end()) {
154 const std::pair<uint8_t, int64_t> &R = AI->second;
155 Value.uval = data.getUnsigned(offset_ptr, AddrSize) + R.second;
156 } else
157 Value.uval = data.getUnsigned(offset_ptr, AddrSize);
158 break;
159 }
160 case DW_FORM_exprloc:
161 case DW_FORM_block:
162 Value.uval = data.getULEB128(offset_ptr);
163 is_block = true;
164 break;
165 case DW_FORM_block1:
166 Value.uval = data.getU8(offset_ptr);
167 is_block = true;
168 break;
169 case DW_FORM_block2:
170 Value.uval = data.getU16(offset_ptr);
171 is_block = true;
172 break;
173 case DW_FORM_block4:
174 Value.uval = data.getU32(offset_ptr);
175 is_block = true;
176 break;
177 case DW_FORM_data1:
178 case DW_FORM_ref1:
179 case DW_FORM_flag:
180 Value.uval = data.getU8(offset_ptr);
181 break;
182 case DW_FORM_data2:
183 case DW_FORM_ref2:
184 Value.uval = data.getU16(offset_ptr);
185 break;
186 case DW_FORM_data4:
187 case DW_FORM_ref4: {
188 Value.uval = data.getU32(offset_ptr);
189 if (!cu)
190 break;
191 RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
192 if (AI != cu->getRelocMap()->end())
193 Value.uval += AI->second.second;
194 break;
195 }
196 case DW_FORM_data8:
197 case DW_FORM_ref8:
198 Value.uval = data.getU64(offset_ptr);
199 break;
200 case DW_FORM_sdata:
201 Value.sval = data.getSLEB128(offset_ptr);
202 break;
203 case DW_FORM_udata:
204 case DW_FORM_ref_udata:
205 Value.uval = data.getULEB128(offset_ptr);
206 break;
207 case DW_FORM_string:
208 Value.cstr = data.getCStr(offset_ptr);
209 break;
210 case DW_FORM_indirect:
211 Form = data.getULEB128(offset_ptr);
212 indirect = true;
213 break;
214 case DW_FORM_sec_offset:
215 case DW_FORM_strp:
216 case DW_FORM_GNU_ref_alt:
217 case DW_FORM_GNU_strp_alt: {
218 // FIXME: This is 64-bit for DWARF64.
219 Value.uval = data.getU32(offset_ptr);
220 if (!cu)
221 break;
222 RelocAddrMap::const_iterator AI =
223 cu->getRelocMap()->find(*offset_ptr - 4);
224 if (AI != cu->getRelocMap()->end())
225 Value.uval += AI->second.second;
226 break;
227 }
228 case DW_FORM_flag_present:
229 Value.uval = 1;
230 break;
231 case DW_FORM_ref_sig8:
232 Value.uval = data.getU64(offset_ptr);
233 break;
234 case DW_FORM_GNU_addr_index:
235 case DW_FORM_GNU_str_index:
236 Value.uval = data.getULEB128(offset_ptr);
237 break;
238 default:
239 return false;
240 }
241 } while (indirect);
242
243 if (is_block) {
244 StringRef str = data.getData().substr(*offset_ptr, Value.uval);
245 Value.data = nullptr;
246 if (!str.empty()) {
247 Value.data = reinterpret_cast<const uint8_t *>(str.data());
248 *offset_ptr += Value.uval;
249 }
250 }
251
252 return true;
253 }
254
255 bool
skipValue(DataExtractor debug_info_data,uint32_t * offset_ptr,const DWARFUnit * cu) const256 DWARFFormValue::skipValue(DataExtractor debug_info_data, uint32_t* offset_ptr,
257 const DWARFUnit *cu) const {
258 return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, cu);
259 }
260
261 bool
skipValue(uint16_t form,DataExtractor debug_info_data,uint32_t * offset_ptr,const DWARFUnit * cu)262 DWARFFormValue::skipValue(uint16_t form, DataExtractor debug_info_data,
263 uint32_t *offset_ptr, const DWARFUnit *cu) {
264 return skipValue(form, debug_info_data, offset_ptr, cu->getVersion(),
265 cu->getAddressByteSize());
266 }
skipValue(uint16_t form,DataExtractor debug_info_data,uint32_t * offset_ptr,uint16_t Version,uint8_t AddrSize)267 bool DWARFFormValue::skipValue(uint16_t form, DataExtractor debug_info_data,
268 uint32_t *offset_ptr, uint16_t Version,
269 uint8_t AddrSize) {
270 bool indirect = false;
271 do {
272 switch (form) {
273 // Blocks if inlined data that have a length field and the data bytes
274 // inlined in the .debug_info
275 case DW_FORM_exprloc:
276 case DW_FORM_block: {
277 uint64_t size = debug_info_data.getULEB128(offset_ptr);
278 *offset_ptr += size;
279 return true;
280 }
281 case DW_FORM_block1: {
282 uint8_t size = debug_info_data.getU8(offset_ptr);
283 *offset_ptr += size;
284 return true;
285 }
286 case DW_FORM_block2: {
287 uint16_t size = debug_info_data.getU16(offset_ptr);
288 *offset_ptr += size;
289 return true;
290 }
291 case DW_FORM_block4: {
292 uint32_t size = debug_info_data.getU32(offset_ptr);
293 *offset_ptr += size;
294 return true;
295 }
296
297 // Inlined NULL terminated C-strings
298 case DW_FORM_string:
299 debug_info_data.getCStr(offset_ptr);
300 return true;
301
302 // Compile unit address sized values
303 case DW_FORM_addr:
304 *offset_ptr += AddrSize;
305 return true;
306 case DW_FORM_ref_addr:
307 *offset_ptr += getRefAddrSize(AddrSize, Version);
308 return true;
309
310 // 0 byte values - implied from the form.
311 case DW_FORM_flag_present:
312 return true;
313
314 // 1 byte values
315 case DW_FORM_data1:
316 case DW_FORM_flag:
317 case DW_FORM_ref1:
318 *offset_ptr += 1;
319 return true;
320
321 // 2 byte values
322 case DW_FORM_data2:
323 case DW_FORM_ref2:
324 *offset_ptr += 2;
325 return true;
326
327 // 4 byte values
328 case DW_FORM_data4:
329 case DW_FORM_ref4:
330 *offset_ptr += 4;
331 return true;
332
333 // 8 byte values
334 case DW_FORM_data8:
335 case DW_FORM_ref8:
336 case DW_FORM_ref_sig8:
337 *offset_ptr += 8;
338 return true;
339
340 // signed or unsigned LEB 128 values
341 // case DW_FORM_APPLE_db_str:
342 case DW_FORM_sdata:
343 case DW_FORM_udata:
344 case DW_FORM_ref_udata:
345 case DW_FORM_GNU_str_index:
346 case DW_FORM_GNU_addr_index:
347 debug_info_data.getULEB128(offset_ptr);
348 return true;
349
350 case DW_FORM_indirect:
351 indirect = true;
352 form = debug_info_data.getULEB128(offset_ptr);
353 break;
354
355 // FIXME: 4 for DWARF32, 8 for DWARF64.
356 case DW_FORM_sec_offset:
357 case DW_FORM_strp:
358 case DW_FORM_GNU_ref_alt:
359 case DW_FORM_GNU_strp_alt:
360 *offset_ptr += 4;
361 return true;
362
363 default:
364 return false;
365 }
366 } while (indirect);
367 return true;
368 }
369
370 void
dump(raw_ostream & OS,const DWARFUnit * cu) const371 DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
372 uint64_t uvalue = Value.uval;
373 bool cu_relative_offset = false;
374
375 switch (Form) {
376 case DW_FORM_addr: OS << format("0x%016" PRIx64, uvalue); break;
377 case DW_FORM_GNU_addr_index: {
378 OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
379 uint64_t Address;
380 if (cu->getAddrOffsetSectionItem(uvalue, Address))
381 OS << format("0x%016" PRIx64, Address);
382 else
383 OS << "<no .debug_addr section>";
384 break;
385 }
386 case DW_FORM_flag_present: OS << "true"; break;
387 case DW_FORM_flag:
388 case DW_FORM_data1: OS << format("0x%02x", (uint8_t)uvalue); break;
389 case DW_FORM_data2: OS << format("0x%04x", (uint16_t)uvalue); break;
390 case DW_FORM_data4: OS << format("0x%08x", (uint32_t)uvalue); break;
391 case DW_FORM_ref_sig8:
392 case DW_FORM_data8: OS << format("0x%016" PRIx64, uvalue); break;
393 case DW_FORM_string:
394 OS << '"';
395 OS.write_escaped(Value.cstr);
396 OS << '"';
397 break;
398 case DW_FORM_exprloc:
399 case DW_FORM_block:
400 case DW_FORM_block1:
401 case DW_FORM_block2:
402 case DW_FORM_block4:
403 if (uvalue > 0) {
404 switch (Form) {
405 case DW_FORM_exprloc:
406 case DW_FORM_block: OS << format("<0x%" PRIx64 "> ", uvalue); break;
407 case DW_FORM_block1: OS << format("<0x%2.2x> ", (uint8_t)uvalue); break;
408 case DW_FORM_block2: OS << format("<0x%4.4x> ", (uint16_t)uvalue); break;
409 case DW_FORM_block4: OS << format("<0x%8.8x> ", (uint32_t)uvalue); break;
410 default: break;
411 }
412
413 const uint8_t* data_ptr = Value.data;
414 if (data_ptr) {
415 // uvalue contains size of block
416 const uint8_t* end_data_ptr = data_ptr + uvalue;
417 while (data_ptr < end_data_ptr) {
418 OS << format("%2.2x ", *data_ptr);
419 ++data_ptr;
420 }
421 }
422 else
423 OS << "NULL";
424 }
425 break;
426
427 case DW_FORM_sdata: OS << Value.sval; break;
428 case DW_FORM_udata: OS << Value.uval; break;
429 case DW_FORM_strp: {
430 OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
431 dumpString(OS, cu);
432 break;
433 }
434 case DW_FORM_GNU_str_index: {
435 OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
436 dumpString(OS, cu);
437 break;
438 }
439 case DW_FORM_GNU_strp_alt: {
440 OS << format("alt indirect string, offset: 0x%" PRIx64 "", uvalue);
441 dumpString(OS, cu);
442 break;
443 }
444 case DW_FORM_ref_addr:
445 OS << format("0x%016" PRIx64, uvalue);
446 break;
447 case DW_FORM_ref1:
448 cu_relative_offset = true;
449 OS << format("cu + 0x%2.2x", (uint8_t)uvalue);
450 break;
451 case DW_FORM_ref2:
452 cu_relative_offset = true;
453 OS << format("cu + 0x%4.4x", (uint16_t)uvalue);
454 break;
455 case DW_FORM_ref4:
456 cu_relative_offset = true;
457 OS << format("cu + 0x%4.4x", (uint32_t)uvalue);
458 break;
459 case DW_FORM_ref8:
460 cu_relative_offset = true;
461 OS << format("cu + 0x%8.8" PRIx64, uvalue);
462 break;
463 case DW_FORM_ref_udata:
464 cu_relative_offset = true;
465 OS << format("cu + 0x%" PRIx64, uvalue);
466 break;
467 case DW_FORM_GNU_ref_alt:
468 OS << format("<alt 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
dumpString(raw_ostream & OS,const DWARFUnit * U) const495 void DWARFFormValue::dumpString(raw_ostream &OS, const DWARFUnit *U) const {
496 Optional<const char *> DbgStr = getAsCString(U);
497 if (DbgStr.hasValue()) {
498 raw_ostream &COS = WithColor(OS, syntax::String);
499 COS << '"';
500 COS.write_escaped(DbgStr.getValue());
501 COS << '"';
502 }
503 }
504
getAsCString(const DWARFUnit * U) const505 Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {
506 if (!isFormClass(FC_String))
507 return None;
508 if (Form == DW_FORM_string)
509 return Value.cstr;
510 // FIXME: Add support for DW_FORM_GNU_strp_alt
511 if (Form == DW_FORM_GNU_strp_alt || U == nullptr)
512 return None;
513 uint32_t Offset = Value.uval;
514 if (Form == DW_FORM_GNU_str_index) {
515 uint32_t StrOffset;
516 if (!U->getStringOffsetSectionItem(Offset, StrOffset))
517 return None;
518 Offset = StrOffset;
519 }
520 if (const char *Str = U->getStringExtractor().getCStr(&Offset)) {
521 return Str;
522 }
523 return None;
524 }
525
getAsAddress(const DWARFUnit * U) const526 Optional<uint64_t> DWARFFormValue::getAsAddress(const DWARFUnit *U) const {
527 if (!isFormClass(FC_Address))
528 return None;
529 if (Form == DW_FORM_GNU_addr_index) {
530 uint32_t Index = Value.uval;
531 uint64_t Result;
532 if (!U || !U->getAddrOffsetSectionItem(Index, Result))
533 return None;
534 return Result;
535 }
536 return Value.uval;
537 }
538
getAsReference(const DWARFUnit * U) const539 Optional<uint64_t> DWARFFormValue::getAsReference(const DWARFUnit *U) const {
540 if (!isFormClass(FC_Reference))
541 return None;
542 switch (Form) {
543 case DW_FORM_ref1:
544 case DW_FORM_ref2:
545 case DW_FORM_ref4:
546 case DW_FORM_ref8:
547 case DW_FORM_ref_udata:
548 if (!U)
549 return None;
550 return Value.uval + U->getOffset();
551 case DW_FORM_ref_addr:
552 return Value.uval;
553 // FIXME: Add proper support for DW_FORM_ref_sig8 and DW_FORM_GNU_ref_alt.
554 default:
555 return None;
556 }
557 }
558
getAsSectionOffset() const559 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const {
560 if (!isFormClass(FC_SectionOffset))
561 return None;
562 return Value.uval;
563 }
564
getAsUnsignedConstant() const565 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const {
566 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag))
567 || Form == DW_FORM_sdata)
568 return None;
569 return Value.uval;
570 }
571
getAsSignedConstant() const572 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const {
573 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) ||
574 (Form == DW_FORM_udata && uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval))
575 return None;
576 switch (Form) {
577 case DW_FORM_data4:
578 return int32_t(Value.uval);
579 case DW_FORM_data2:
580 return int16_t(Value.uval);
581 case DW_FORM_data1:
582 return int8_t(Value.uval);
583 case DW_FORM_sdata:
584 case DW_FORM_data8:
585 default:
586 return Value.sval;
587 }
588 }
589
getAsBlock() const590 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const {
591 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc))
592 return None;
593 return makeArrayRef(Value.data, Value.uval);
594 }
595
596