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 "DWARFFormValue.h"
11 #include "DWARFCompileUnit.h"
12 #include "DWARFContext.h"
13 #include "llvm/Support/Debug.h"
14 #include "llvm/Support/Dwarf.h"
15 #include "llvm/Support/Format.h"
16 #include "llvm/Support/raw_ostream.h"
17 #include <cassert>
18 using namespace llvm;
19 using namespace dwarf;
20
21 static const uint8_t form_sizes_addr4[] = {
22 0, // 0x00 unused
23 4, // 0x01 DW_FORM_addr
24 0, // 0x02 unused
25 0, // 0x03 DW_FORM_block2
26 0, // 0x04 DW_FORM_block4
27 2, // 0x05 DW_FORM_data2
28 4, // 0x06 DW_FORM_data4
29 8, // 0x07 DW_FORM_data8
30 0, // 0x08 DW_FORM_string
31 0, // 0x09 DW_FORM_block
32 0, // 0x0a DW_FORM_block1
33 1, // 0x0b DW_FORM_data1
34 1, // 0x0c DW_FORM_flag
35 0, // 0x0d DW_FORM_sdata
36 4, // 0x0e DW_FORM_strp
37 0, // 0x0f DW_FORM_udata
38 4, // 0x10 DW_FORM_ref_addr
39 1, // 0x11 DW_FORM_ref1
40 2, // 0x12 DW_FORM_ref2
41 4, // 0x13 DW_FORM_ref4
42 8, // 0x14 DW_FORM_ref8
43 0, // 0x15 DW_FORM_ref_udata
44 0, // 0x16 DW_FORM_indirect
45 4, // 0x17 DW_FORM_sec_offset
46 0, // 0x18 DW_FORM_exprloc
47 0, // 0x19 DW_FORM_flag_present
48 8, // 0x20 DW_FORM_ref_sig8
49 };
50
51 static const uint8_t form_sizes_addr8[] = {
52 0, // 0x00 unused
53 8, // 0x01 DW_FORM_addr
54 0, // 0x02 unused
55 0, // 0x03 DW_FORM_block2
56 0, // 0x04 DW_FORM_block4
57 2, // 0x05 DW_FORM_data2
58 4, // 0x06 DW_FORM_data4
59 8, // 0x07 DW_FORM_data8
60 0, // 0x08 DW_FORM_string
61 0, // 0x09 DW_FORM_block
62 0, // 0x0a DW_FORM_block1
63 1, // 0x0b DW_FORM_data1
64 1, // 0x0c DW_FORM_flag
65 0, // 0x0d DW_FORM_sdata
66 4, // 0x0e DW_FORM_strp
67 0, // 0x0f DW_FORM_udata
68 8, // 0x10 DW_FORM_ref_addr
69 1, // 0x11 DW_FORM_ref1
70 2, // 0x12 DW_FORM_ref2
71 4, // 0x13 DW_FORM_ref4
72 8, // 0x14 DW_FORM_ref8
73 0, // 0x15 DW_FORM_ref_udata
74 0, // 0x16 DW_FORM_indirect
75 4, // 0x17 DW_FORM_sec_offset
76 0, // 0x18 DW_FORM_exprloc
77 0, // 0x19 DW_FORM_flag_present
78 8, // 0x20 DW_FORM_ref_sig8
79 };
80
81 const uint8_t *
getFixedFormSizesForAddressSize(uint8_t addr_size)82 DWARFFormValue::getFixedFormSizesForAddressSize(uint8_t addr_size) {
83 switch (addr_size) {
84 case 4: return form_sizes_addr4;
85 case 8: return form_sizes_addr8;
86 }
87 return NULL;
88 }
89
90 bool
extractValue(DataExtractor data,uint32_t * offset_ptr,const DWARFCompileUnit * cu)91 DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
92 const DWARFCompileUnit *cu) {
93 bool indirect = false;
94 bool is_block = false;
95 Value.data = NULL;
96 // Read the value for the form into value and follow and DW_FORM_indirect
97 // instances we run into
98 do {
99 indirect = false;
100 switch (Form) {
101 case DW_FORM_addr:
102 case DW_FORM_ref_addr: {
103 RelocAddrMap::const_iterator AI
104 = cu->getRelocMap()->find(*offset_ptr);
105 if (AI != cu->getRelocMap()->end()) {
106 const std::pair<uint8_t, int64_t> &R = AI->second;
107 Value.uval = data.getUnsigned(offset_ptr, cu->getAddressByteSize()) +
108 R.second;
109 } else
110 Value.uval = data.getUnsigned(offset_ptr, cu->getAddressByteSize());
111 break;
112 }
113 case DW_FORM_exprloc:
114 case DW_FORM_block:
115 Value.uval = data.getULEB128(offset_ptr);
116 is_block = true;
117 break;
118 case DW_FORM_block1:
119 Value.uval = data.getU8(offset_ptr);
120 is_block = true;
121 break;
122 case DW_FORM_block2:
123 Value.uval = data.getU16(offset_ptr);
124 is_block = true;
125 break;
126 case DW_FORM_block4:
127 Value.uval = data.getU32(offset_ptr);
128 is_block = true;
129 break;
130 case DW_FORM_data1:
131 case DW_FORM_ref1:
132 case DW_FORM_flag:
133 Value.uval = data.getU8(offset_ptr);
134 break;
135 case DW_FORM_data2:
136 case DW_FORM_ref2:
137 Value.uval = data.getU16(offset_ptr);
138 break;
139 case DW_FORM_data4:
140 case DW_FORM_ref4:
141 Value.uval = data.getU32(offset_ptr);
142 break;
143 case DW_FORM_data8:
144 case DW_FORM_ref8:
145 Value.uval = data.getU64(offset_ptr);
146 break;
147 case DW_FORM_sdata:
148 Value.sval = data.getSLEB128(offset_ptr);
149 break;
150 case DW_FORM_strp: {
151 RelocAddrMap::const_iterator AI
152 = 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.getU32(offset_ptr) + R.second;
156 } else
157 Value.uval = data.getU32(offset_ptr);
158 break;
159 }
160 case DW_FORM_udata:
161 case DW_FORM_ref_udata:
162 Value.uval = data.getULEB128(offset_ptr);
163 break;
164 case DW_FORM_string:
165 Value.cstr = data.getCStr(offset_ptr);
166 // Set the string value to also be the data for inlined cstr form
167 // values only so we can tell the differnence between DW_FORM_string
168 // and DW_FORM_strp form values
169 Value.data = (const uint8_t*)Value.cstr;
170 break;
171 case DW_FORM_indirect:
172 Form = data.getULEB128(offset_ptr);
173 indirect = true;
174 break;
175 case DW_FORM_sec_offset:
176 // FIXME: This is 64-bit for DWARF64.
177 Value.uval = data.getU32(offset_ptr);
178 break;
179 case DW_FORM_flag_present:
180 Value.uval = 1;
181 break;
182 case DW_FORM_ref_sig8:
183 Value.uval = data.getU64(offset_ptr);
184 break;
185 case DW_FORM_GNU_addr_index:
186 Value.uval = data.getULEB128(offset_ptr);
187 break;
188 case DW_FORM_GNU_str_index:
189 Value.uval = data.getULEB128(offset_ptr);
190 break;
191 default:
192 return false;
193 }
194 } while (indirect);
195
196 if (is_block) {
197 StringRef str = data.getData().substr(*offset_ptr, Value.uval);
198 Value.data = NULL;
199 if (!str.empty()) {
200 Value.data = reinterpret_cast<const uint8_t *>(str.data());
201 *offset_ptr += Value.uval;
202 }
203 }
204
205 return true;
206 }
207
208 bool
skipValue(DataExtractor debug_info_data,uint32_t * offset_ptr,const DWARFCompileUnit * cu) const209 DWARFFormValue::skipValue(DataExtractor debug_info_data, uint32_t* offset_ptr,
210 const DWARFCompileUnit *cu) const {
211 return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, cu);
212 }
213
214 bool
skipValue(uint16_t form,DataExtractor debug_info_data,uint32_t * offset_ptr,const DWARFCompileUnit * cu)215 DWARFFormValue::skipValue(uint16_t form, DataExtractor debug_info_data,
216 uint32_t *offset_ptr, const DWARFCompileUnit *cu) {
217 bool indirect = false;
218 do {
219 indirect = false;
220 switch (form) {
221 // Blocks if inlined data that have a length field and the data bytes
222 // inlined in the .debug_info
223 case DW_FORM_exprloc:
224 case DW_FORM_block: {
225 uint64_t size = debug_info_data.getULEB128(offset_ptr);
226 *offset_ptr += size;
227 return true;
228 }
229 case DW_FORM_block1: {
230 uint8_t size = debug_info_data.getU8(offset_ptr);
231 *offset_ptr += size;
232 return true;
233 }
234 case DW_FORM_block2: {
235 uint16_t size = debug_info_data.getU16(offset_ptr);
236 *offset_ptr += size;
237 return true;
238 }
239 case DW_FORM_block4: {
240 uint32_t size = debug_info_data.getU32(offset_ptr);
241 *offset_ptr += size;
242 return true;
243 }
244
245 // Inlined NULL terminated C-strings
246 case DW_FORM_string:
247 debug_info_data.getCStr(offset_ptr);
248 return true;
249
250 // Compile unit address sized values
251 case DW_FORM_addr:
252 case DW_FORM_ref_addr:
253 *offset_ptr += cu->getAddressByteSize();
254 return true;
255
256 // 0 byte values - implied from the form.
257 case DW_FORM_flag_present:
258 return true;
259
260 // 1 byte values
261 case DW_FORM_data1:
262 case DW_FORM_flag:
263 case DW_FORM_ref1:
264 *offset_ptr += 1;
265 return true;
266
267 // 2 byte values
268 case DW_FORM_data2:
269 case DW_FORM_ref2:
270 *offset_ptr += 2;
271 return true;
272
273 // 4 byte values
274 case DW_FORM_strp:
275 case DW_FORM_data4:
276 case DW_FORM_ref4:
277 *offset_ptr += 4;
278 return true;
279
280 // 8 byte values
281 case DW_FORM_data8:
282 case DW_FORM_ref8:
283 case DW_FORM_ref_sig8:
284 *offset_ptr += 8;
285 return true;
286
287 // signed or unsigned LEB 128 values
288 // case DW_FORM_APPLE_db_str:
289 case DW_FORM_sdata:
290 case DW_FORM_udata:
291 case DW_FORM_ref_udata:
292 case DW_FORM_GNU_str_index:
293 case DW_FORM_GNU_addr_index:
294 debug_info_data.getULEB128(offset_ptr);
295 return true;
296
297 case DW_FORM_indirect:
298 indirect = true;
299 form = debug_info_data.getULEB128(offset_ptr);
300 break;
301
302 // FIXME: 4 for DWARF32, 8 for DWARF64.
303 case DW_FORM_sec_offset:
304 *offset_ptr += 4;
305 return true;
306
307 default:
308 return false;
309 }
310 } while (indirect);
311 return true;
312 }
313
314 void
dump(raw_ostream & OS,const DWARFCompileUnit * cu) const315 DWARFFormValue::dump(raw_ostream &OS, const DWARFCompileUnit *cu) const {
316 DataExtractor debug_str_data(cu->getStringSection(), true, 0);
317 DataExtractor debug_str_offset_data(cu->getStringOffsetSection(), true, 0);
318 uint64_t uvalue = getUnsigned();
319 bool cu_relative_offset = false;
320
321 switch (Form) {
322 case DW_FORM_addr: OS << format("0x%016" PRIx64, uvalue); break;
323 case DW_FORM_GNU_addr_index: {
324 StringRef AddrOffsetSec = cu->getAddrOffsetSection();
325 OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
326 if (AddrOffsetSec.size() != 0) {
327 DataExtractor DA(AddrOffsetSec, true, cu->getAddressByteSize());
328 OS << format("0x%016" PRIx64, getIndirectAddress(&DA, cu));
329 } else
330 OS << "<no .debug_addr section>";
331 break;
332 }
333 case DW_FORM_flag_present: OS << "true"; break;
334 case DW_FORM_flag:
335 case DW_FORM_data1: OS << format("0x%02x", (uint8_t)uvalue); break;
336 case DW_FORM_data2: OS << format("0x%04x", (uint16_t)uvalue); break;
337 case DW_FORM_data4: OS << format("0x%08x", (uint32_t)uvalue); break;
338 case DW_FORM_ref_sig8:
339 case DW_FORM_data8: OS << format("0x%016" PRIx64, uvalue); break;
340 case DW_FORM_string:
341 OS << '"';
342 OS.write_escaped(getAsCString(NULL));
343 OS << '"';
344 break;
345 case DW_FORM_exprloc:
346 case DW_FORM_block:
347 case DW_FORM_block1:
348 case DW_FORM_block2:
349 case DW_FORM_block4:
350 if (uvalue > 0) {
351 switch (Form) {
352 case DW_FORM_exprloc:
353 case DW_FORM_block: OS << format("<0x%" PRIx64 "> ", uvalue); break;
354 case DW_FORM_block1: OS << format("<0x%2.2x> ", (uint8_t)uvalue); break;
355 case DW_FORM_block2: OS << format("<0x%4.4x> ", (uint16_t)uvalue); break;
356 case DW_FORM_block4: OS << format("<0x%8.8x> ", (uint32_t)uvalue); break;
357 default: break;
358 }
359
360 const uint8_t* data_ptr = Value.data;
361 if (data_ptr) {
362 // uvalue contains size of block
363 const uint8_t* end_data_ptr = data_ptr + uvalue;
364 while (data_ptr < end_data_ptr) {
365 OS << format("%2.2x ", *data_ptr);
366 ++data_ptr;
367 }
368 }
369 else
370 OS << "NULL";
371 }
372 break;
373
374 case DW_FORM_sdata: OS << getSigned(); break;
375 case DW_FORM_udata: OS << getUnsigned(); break;
376 case DW_FORM_strp: {
377 OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
378 const char* dbg_str = getAsCString(&debug_str_data);
379 if (dbg_str) {
380 OS << '"';
381 OS.write_escaped(dbg_str);
382 OS << '"';
383 }
384 break;
385 }
386 case DW_FORM_GNU_str_index: {
387 OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
388 const char *dbg_str = getIndirectCString(&debug_str_data,
389 &debug_str_offset_data);
390 if (dbg_str) {
391 OS << '"';
392 OS.write_escaped(dbg_str);
393 OS << '"';
394 }
395 break;
396 }
397 case DW_FORM_ref_addr:
398 OS << format("0x%016" PRIx64, uvalue);
399 break;
400 case DW_FORM_ref1:
401 cu_relative_offset = true;
402 OS << format("cu + 0x%2.2x", (uint8_t)uvalue);
403 break;
404 case DW_FORM_ref2:
405 cu_relative_offset = true;
406 OS << format("cu + 0x%4.4x", (uint16_t)uvalue);
407 break;
408 case DW_FORM_ref4:
409 cu_relative_offset = true;
410 OS << format("cu + 0x%4.4x", (uint32_t)uvalue);
411 break;
412 case DW_FORM_ref8:
413 cu_relative_offset = true;
414 OS << format("cu + 0x%8.8" PRIx64, uvalue);
415 break;
416 case DW_FORM_ref_udata:
417 cu_relative_offset = true;
418 OS << format("cu + 0x%" PRIx64, uvalue);
419 break;
420
421 // All DW_FORM_indirect attributes should be resolved prior to calling
422 // this function
423 case DW_FORM_indirect:
424 OS << "DW_FORM_indirect";
425 break;
426
427 // Should be formatted to 64-bit for DWARF64.
428 case DW_FORM_sec_offset:
429 OS << format("0x%08x", (uint32_t)uvalue);
430 break;
431
432 default:
433 OS << format("DW_FORM(0x%4.4x)", Form);
434 break;
435 }
436
437 if (cu_relative_offset)
438 OS << format(" => {0x%8.8" PRIx64 "}", uvalue + (cu ? cu->getOffset() : 0));
439 }
440
441 const char*
getAsCString(const DataExtractor * debug_str_data_ptr) const442 DWARFFormValue::getAsCString(const DataExtractor *debug_str_data_ptr) const {
443 if (isInlinedCStr()) {
444 return Value.cstr;
445 } else if (debug_str_data_ptr) {
446 uint32_t offset = Value.uval;
447 return debug_str_data_ptr->getCStr(&offset);
448 }
449 return NULL;
450 }
451
452 const char*
getIndirectCString(const DataExtractor * DS,const DataExtractor * DSO) const453 DWARFFormValue::getIndirectCString(const DataExtractor *DS,
454 const DataExtractor *DSO) const {
455 if (!DS || !DSO) return NULL;
456
457 uint32_t offset = Value.uval * 4;
458 uint32_t soffset = DSO->getU32(&offset);
459 return DS->getCStr(&soffset);
460 }
461
462 uint64_t
getIndirectAddress(const DataExtractor * DA,const DWARFCompileUnit * cu) const463 DWARFFormValue::getIndirectAddress(const DataExtractor *DA,
464 const DWARFCompileUnit *cu) const {
465 if (!DA) return 0;
466
467 uint32_t offset = Value.uval * cu->getAddressByteSize();
468 return DA->getAddress(&offset);
469 }
470
getReference(const DWARFCompileUnit * cu) const471 uint64_t DWARFFormValue::getReference(const DWARFCompileUnit *cu) const {
472 uint64_t die_offset = Value.uval;
473 switch (Form) {
474 case DW_FORM_ref1:
475 case DW_FORM_ref2:
476 case DW_FORM_ref4:
477 case DW_FORM_ref8:
478 case DW_FORM_ref_udata:
479 die_offset += (cu ? cu->getOffset() : 0);
480 break;
481 default:
482 break;
483 }
484
485 return die_offset;
486 }
487
488 bool
resolveCompileUnitReferences(const DWARFCompileUnit * cu)489 DWARFFormValue::resolveCompileUnitReferences(const DWARFCompileUnit *cu) {
490 switch (Form) {
491 case DW_FORM_ref1:
492 case DW_FORM_ref2:
493 case DW_FORM_ref4:
494 case DW_FORM_ref8:
495 case DW_FORM_ref_udata:
496 Value.uval += cu->getOffset();
497 Form = DW_FORM_ref_addr;
498 return true;
499 default:
500 break;
501 }
502 return false;
503 }
504
BlockData() const505 const uint8_t *DWARFFormValue::BlockData() const {
506 if (!isInlinedCStr())
507 return Value.data;
508 return NULL;
509 }
510
isBlockForm(uint16_t form)511 bool DWARFFormValue::isBlockForm(uint16_t form) {
512 switch (form) {
513 case DW_FORM_exprloc:
514 case DW_FORM_block:
515 case DW_FORM_block1:
516 case DW_FORM_block2:
517 case DW_FORM_block4:
518 return true;
519 }
520 return false;
521 }
522
isDataForm(uint16_t form)523 bool DWARFFormValue::isDataForm(uint16_t form) {
524 switch (form) {
525 case DW_FORM_sdata:
526 case DW_FORM_udata:
527 case DW_FORM_data1:
528 case DW_FORM_data2:
529 case DW_FORM_data4:
530 case DW_FORM_data8:
531 return true;
532 }
533 return false;
534 }
535