1 //===- DWARFFormValue.cpp -------------------------------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
10 #include "llvm/ADT/ArrayRef.h"
11 #include "llvm/ADT/None.h"
12 #include "llvm/ADT/Optional.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/BinaryFormat/Dwarf.h"
15 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
16 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
17 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
18 #include "llvm/Support/ErrorHandling.h"
19 #include "llvm/Support/Format.h"
20 #include "llvm/Support/WithColor.h"
21 #include "llvm/Support/raw_ostream.h"
27 using namespace dwarf;
29 static const DWARFFormValue::FormClass DWARF5FormClasses[] = {
30 DWARFFormValue::FC_Unknown, // 0x0
31 DWARFFormValue::FC_Address, // 0x01 DW_FORM_addr
32 DWARFFormValue::FC_Unknown, // 0x02 unused
33 DWARFFormValue::FC_Block, // 0x03 DW_FORM_block2
34 DWARFFormValue::FC_Block, // 0x04 DW_FORM_block4
35 DWARFFormValue::FC_Constant, // 0x05 DW_FORM_data2
36 // --- These can be FC_SectionOffset in DWARF3 and below:
37 DWARFFormValue::FC_Constant, // 0x06 DW_FORM_data4
38 DWARFFormValue::FC_Constant, // 0x07 DW_FORM_data8
40 DWARFFormValue::FC_String, // 0x08 DW_FORM_string
41 DWARFFormValue::FC_Block, // 0x09 DW_FORM_block
42 DWARFFormValue::FC_Block, // 0x0a DW_FORM_block1
43 DWARFFormValue::FC_Constant, // 0x0b DW_FORM_data1
44 DWARFFormValue::FC_Flag, // 0x0c DW_FORM_flag
45 DWARFFormValue::FC_Constant, // 0x0d DW_FORM_sdata
46 DWARFFormValue::FC_String, // 0x0e DW_FORM_strp
47 DWARFFormValue::FC_Constant, // 0x0f DW_FORM_udata
48 DWARFFormValue::FC_Reference, // 0x10 DW_FORM_ref_addr
49 DWARFFormValue::FC_Reference, // 0x11 DW_FORM_ref1
50 DWARFFormValue::FC_Reference, // 0x12 DW_FORM_ref2
51 DWARFFormValue::FC_Reference, // 0x13 DW_FORM_ref4
52 DWARFFormValue::FC_Reference, // 0x14 DW_FORM_ref8
53 DWARFFormValue::FC_Reference, // 0x15 DW_FORM_ref_udata
54 DWARFFormValue::FC_Indirect, // 0x16 DW_FORM_indirect
55 DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset
56 DWARFFormValue::FC_Exprloc, // 0x18 DW_FORM_exprloc
57 DWARFFormValue::FC_Flag, // 0x19 DW_FORM_flag_present
58 DWARFFormValue::FC_String, // 0x1a DW_FORM_strx
59 DWARFFormValue::FC_Address, // 0x1b DW_FORM_addrx
60 DWARFFormValue::FC_Reference, // 0x1c DW_FORM_ref_sup4
61 DWARFFormValue::FC_String, // 0x1d DW_FORM_strp_sup
62 DWARFFormValue::FC_Constant, // 0x1e DW_FORM_data16
63 DWARFFormValue::FC_String, // 0x1f DW_FORM_line_strp
64 DWARFFormValue::FC_Reference, // 0x20 DW_FORM_ref_sig8
65 DWARFFormValue::FC_Constant, // 0x21 DW_FORM_implicit_const
66 DWARFFormValue::FC_SectionOffset, // 0x22 DW_FORM_loclistx
67 DWARFFormValue::FC_SectionOffset, // 0x23 DW_FORM_rnglistx
68 DWARFFormValue::FC_Reference, // 0x24 DW_FORM_ref_sup8
69 DWARFFormValue::FC_String, // 0x25 DW_FORM_strx1
70 DWARFFormValue::FC_String, // 0x26 DW_FORM_strx2
71 DWARFFormValue::FC_String, // 0x27 DW_FORM_strx3
72 DWARFFormValue::FC_String, // 0x28 DW_FORM_strx4
73 DWARFFormValue::FC_Address, // 0x29 DW_FORM_addrx1
74 DWARFFormValue::FC_Address, // 0x2a DW_FORM_addrx2
75 DWARFFormValue::FC_Address, // 0x2b DW_FORM_addrx3
76 DWARFFormValue::FC_Address, // 0x2c DW_FORM_addrx4
80 DWARFFormValue DWARFFormValue::createFromSValue(dwarf::Form F, int64_t V) {
81 return DWARFFormValue(F, ValueType(V));
84 DWARFFormValue DWARFFormValue::createFromUValue(dwarf::Form F, uint64_t V) {
85 return DWARFFormValue(F, ValueType(V));
88 DWARFFormValue DWARFFormValue::createFromPValue(dwarf::Form F, const char *V) {
89 return DWARFFormValue(F, ValueType(V));
92 DWARFFormValue DWARFFormValue::createFromBlockValue(dwarf::Form F,
93 ArrayRef<uint8_t> D) {
97 return DWARFFormValue(F, V);
100 DWARFFormValue DWARFFormValue::createFromUnit(dwarf::Form F, const DWARFUnit *U,
101 uint32_t *OffsetPtr) {
102 DWARFFormValue FormValue(F);
103 FormValue.extractValue(U->getDebugInfoExtractor(), OffsetPtr,
104 U->getFormParams(), U);
108 bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData,
110 const dwarf::FormParams Params) {
111 bool Indirect = false;
114 // Blocks of inlined data that have a length field and the data bytes
115 // inlined in the .debug_info.
116 case DW_FORM_exprloc:
117 case DW_FORM_block: {
118 uint64_t size = DebugInfoData.getULEB128(OffsetPtr);
122 case DW_FORM_block1: {
123 uint8_t size = DebugInfoData.getU8(OffsetPtr);
127 case DW_FORM_block2: {
128 uint16_t size = DebugInfoData.getU16(OffsetPtr);
132 case DW_FORM_block4: {
133 uint32_t size = DebugInfoData.getU32(OffsetPtr);
138 // Inlined NULL terminated C-strings.
140 DebugInfoData.getCStr(OffsetPtr);
144 case DW_FORM_ref_addr:
145 case DW_FORM_flag_present:
156 case DW_FORM_ref_sig8:
157 case DW_FORM_ref_sup4:
158 case DW_FORM_ref_sup8:
165 case DW_FORM_sec_offset:
167 case DW_FORM_strp_sup:
168 case DW_FORM_line_strp:
169 case DW_FORM_GNU_ref_alt:
170 case DW_FORM_GNU_strp_alt:
171 if (Optional<uint8_t> FixedSize =
172 dwarf::getFixedFormByteSize(Form, Params)) {
173 *OffsetPtr += *FixedSize;
178 // signed or unsigned LEB 128 values.
180 DebugInfoData.getSLEB128(OffsetPtr);
184 case DW_FORM_ref_udata:
187 case DW_FORM_loclistx:
188 case DW_FORM_rnglistx:
189 case DW_FORM_GNU_addr_index:
190 case DW_FORM_GNU_str_index:
191 DebugInfoData.getULEB128(OffsetPtr);
194 case DW_FORM_indirect:
196 Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr));
206 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
207 // First, check DWARF5 form classes.
208 if (Form < makeArrayRef(DWARF5FormClasses).size() &&
209 DWARF5FormClasses[Form] == FC)
211 // Check more forms from extensions and proposals.
213 case DW_FORM_GNU_ref_alt:
214 return (FC == FC_Reference);
215 case DW_FORM_GNU_addr_index:
216 return (FC == FC_Address);
217 case DW_FORM_GNU_str_index:
218 case DW_FORM_GNU_strp_alt:
219 return (FC == FC_String);
224 if (FC == FC_SectionOffset) {
225 if (Form == DW_FORM_strp || Form == DW_FORM_line_strp)
227 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section
228 // offset. If we don't have a DWARFUnit, default to the old behavior.
229 if (Form == DW_FORM_data4 || Form == DW_FORM_data8)
230 return !U || U->getVersion() <= 3;
236 bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data,
237 uint32_t *OffsetPtr, dwarf::FormParams FP,
238 const DWARFContext *Ctx,
239 const DWARFUnit *CU) {
241 Ctx = &CU->getContext();
244 bool Indirect = false;
245 bool IsBlock = false;
246 Value.data = nullptr;
247 // Read the value for the form into value and follow and DW_FORM_indirect
248 // instances we run into
253 case DW_FORM_ref_addr: {
255 (Form == DW_FORM_addr) ? FP.AddrSize : FP.getRefAddrByteSize();
256 Value.uval = Data.getRelocatedValue(Size, OffsetPtr, &Value.SectionIndex);
259 case DW_FORM_exprloc:
261 Value.uval = Data.getULEB128(OffsetPtr);
265 Value.uval = Data.getU8(OffsetPtr);
269 Value.uval = Data.getU16(OffsetPtr);
273 Value.uval = Data.getU32(OffsetPtr);
281 Value.uval = Data.getU8(OffsetPtr);
287 Value.uval = Data.getU16(OffsetPtr);
290 Value.uval = Data.getU24(OffsetPtr);
294 case DW_FORM_ref_sup4:
297 Value.uval = Data.getRelocatedValue(4, OffsetPtr);
301 case DW_FORM_ref_sup8:
302 Value.uval = Data.getRelocatedValue(8, OffsetPtr);
305 // Treat this like a 16-byte block.
310 Value.sval = Data.getSLEB128(OffsetPtr);
313 case DW_FORM_ref_udata:
314 case DW_FORM_rnglistx:
315 Value.uval = Data.getULEB128(OffsetPtr);
318 Value.cstr = Data.getCStr(OffsetPtr);
320 case DW_FORM_indirect:
321 Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr));
325 case DW_FORM_sec_offset:
326 case DW_FORM_GNU_ref_alt:
327 case DW_FORM_GNU_strp_alt:
328 case DW_FORM_line_strp:
329 case DW_FORM_strp_sup: {
331 Data.getRelocatedValue(FP.getDwarfOffsetByteSize(), OffsetPtr);
334 case DW_FORM_flag_present:
337 case DW_FORM_ref_sig8:
338 Value.uval = Data.getU64(OffsetPtr);
340 case DW_FORM_GNU_addr_index:
341 case DW_FORM_GNU_str_index:
344 Value.uval = Data.getULEB128(OffsetPtr);
347 // DWARFFormValue::skipValue() will have caught this and caused all
348 // DWARF DIEs to fail to be parsed, so this code is not be reachable.
349 llvm_unreachable("unsupported form");
354 StringRef Str = Data.getData().substr(*OffsetPtr, Value.uval);
355 Value.data = nullptr;
357 Value.data = Str.bytes_begin();
358 *OffsetPtr += Value.uval;
365 void DWARFFormValue::dumpSectionedAddress(raw_ostream &OS,
366 DIDumpOptions DumpOpts,
367 object::SectionedAddress SA) const {
368 OS << format("0x%016" PRIx64, SA.Address);
369 dumpAddressSection(U->getContext().getDWARFObj(), OS, DumpOpts,
373 void DWARFFormValue::dumpAddressSection(const DWARFObject &Obj, raw_ostream &OS,
374 DIDumpOptions DumpOpts,
375 uint64_t SectionIndex) {
376 if (!DumpOpts.Verbose || SectionIndex == -1ULL)
378 ArrayRef<SectionName> SectionNames = Obj.getSectionNames();
379 const auto &SecRef = SectionNames[SectionIndex];
381 OS << " \"" << SecRef.Name << '\"';
383 // Print section index if name is not unique.
384 if (!SecRef.IsNameUnique)
385 OS << format(" [%" PRIu64 "]", SectionIndex);
388 void DWARFFormValue::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const {
389 uint64_t UValue = Value.uval;
390 bool CURelativeOffset = false;
391 raw_ostream &AddrOS = DumpOpts.ShowAddresses
392 ? WithColor(OS, HighlightColor::Address).get()
396 dumpSectionedAddress(AddrOS, DumpOpts, {Value.uval, Value.SectionIndex});
403 case DW_FORM_GNU_addr_index: {
405 OS << "<invalid dwarf unit>";
408 Optional<object::SectionedAddress> A = U->getAddrOffsetSectionItem(UValue);
409 if (!A || DumpOpts.Verbose)
410 AddrOS << format("indexed (%8.8x) address = ", (uint32_t)UValue);
412 dumpSectionedAddress(AddrOS, DumpOpts, *A);
414 OS << "<no .debug_addr section>";
417 case DW_FORM_flag_present:
422 OS << format("0x%02x", (uint8_t)UValue);
425 OS << format("0x%04x", (uint16_t)UValue);
428 OS << format("0x%08x", (uint32_t)UValue);
430 case DW_FORM_ref_sig8:
431 AddrOS << format("0x%016" PRIx64, UValue);
434 OS << format("0x%016" PRIx64, UValue);
437 OS << format_bytes(ArrayRef<uint8_t>(Value.data, 16), None, 16, 16);
441 OS.write_escaped(Value.cstr);
444 case DW_FORM_exprloc:
451 case DW_FORM_exprloc:
453 AddrOS << format("<0x%" PRIx64 "> ", UValue);
456 AddrOS << format("<0x%2.2x> ", (uint8_t)UValue);
459 AddrOS << format("<0x%4.4x> ", (uint16_t)UValue);
462 AddrOS << format("<0x%8.8x> ", (uint32_t)UValue);
468 const uint8_t *DataPtr = Value.data;
470 // UValue contains size of block
471 const uint8_t *EndDataPtr = DataPtr + UValue;
472 while (DataPtr < EndDataPtr) {
473 AddrOS << format("%2.2x ", *DataPtr);
488 if (DumpOpts.Verbose)
489 OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)UValue);
492 case DW_FORM_line_strp:
493 if (DumpOpts.Verbose)
494 OS << format(" .debug_line_str[0x%8.8x] = ", (uint32_t)UValue);
502 case DW_FORM_GNU_str_index:
503 if (DumpOpts.Verbose)
504 OS << format("indexed (%8.8x) string = ", (uint32_t)UValue);
507 case DW_FORM_GNU_strp_alt:
508 if (DumpOpts.Verbose)
509 OS << format("alt indirect string, offset: 0x%" PRIx64 "", UValue);
512 case DW_FORM_ref_addr:
513 AddrOS << format("0x%016" PRIx64, UValue);
516 CURelativeOffset = true;
517 if (DumpOpts.Verbose)
518 AddrOS << format("cu + 0x%2.2x", (uint8_t)UValue);
521 CURelativeOffset = true;
522 if (DumpOpts.Verbose)
523 AddrOS << format("cu + 0x%4.4x", (uint16_t)UValue);
526 CURelativeOffset = true;
527 if (DumpOpts.Verbose)
528 AddrOS << format("cu + 0x%4.4x", (uint32_t)UValue);
531 CURelativeOffset = true;
532 if (DumpOpts.Verbose)
533 AddrOS << format("cu + 0x%8.8" PRIx64, UValue);
535 case DW_FORM_ref_udata:
536 CURelativeOffset = true;
537 if (DumpOpts.Verbose)
538 AddrOS << format("cu + 0x%" PRIx64, UValue);
540 case DW_FORM_GNU_ref_alt:
541 AddrOS << format("<alt 0x%" PRIx64 ">", UValue);
544 // All DW_FORM_indirect attributes should be resolved prior to calling
546 case DW_FORM_indirect:
547 OS << "DW_FORM_indirect";
550 case DW_FORM_rnglistx:
551 OS << format("indexed (0x%x) rangelist = ", (uint32_t)UValue);
554 // Should be formatted to 64-bit for DWARF64.
555 case DW_FORM_sec_offset:
556 AddrOS << format("0x%08x", (uint32_t)UValue);
560 OS << format("DW_FORM(0x%4.4x)", Form);
564 if (CURelativeOffset) {
565 if (DumpOpts.Verbose)
567 if (DumpOpts.ShowAddresses)
568 WithColor(OS, HighlightColor::Address).get()
569 << format("0x%8.8" PRIx64, UValue + (U ? U->getOffset() : 0));
570 if (DumpOpts.Verbose)
575 void DWARFFormValue::dumpString(raw_ostream &OS) const {
576 Optional<const char *> DbgStr = getAsCString();
577 if (DbgStr.hasValue()) {
578 auto COS = WithColor(OS, HighlightColor::String);
580 COS.get().write_escaped(DbgStr.getValue());
585 Optional<const char *> DWARFFormValue::getAsCString() const {
586 if (!isFormClass(FC_String))
588 if (Form == DW_FORM_string)
590 // FIXME: Add support for DW_FORM_GNU_strp_alt
591 if (Form == DW_FORM_GNU_strp_alt || C == nullptr)
593 uint32_t Offset = Value.uval;
594 if (Form == DW_FORM_line_strp) {
595 // .debug_line_str is tracked in the Context.
596 if (const char *Str = C->getLineStringExtractor().getCStr(&Offset))
600 if (Form == DW_FORM_GNU_str_index || Form == DW_FORM_strx ||
601 Form == DW_FORM_strx1 || Form == DW_FORM_strx2 || Form == DW_FORM_strx3 ||
602 Form == DW_FORM_strx4) {
605 Optional<uint64_t> StrOffset = U->getStringOffsetSectionItem(Offset);
610 // Prefer the Unit's string extractor, because for .dwo it will point to
611 // .debug_str.dwo, while the Context's extractor always uses .debug_str.
613 if (const char *Str = U->getStringExtractor().getCStr(&Offset))
617 if (const char *Str = C->getStringExtractor().getCStr(&Offset))
622 Optional<uint64_t> DWARFFormValue::getAsAddress() const {
623 if (auto SA = getAsSectionedAddress())
627 Optional<object::SectionedAddress>
628 DWARFFormValue::getAsSectionedAddress() const {
629 if (!isFormClass(FC_Address))
631 if (Form == DW_FORM_GNU_addr_index || Form == DW_FORM_addrx) {
632 uint32_t Index = Value.uval;
635 Optional<object::SectionedAddress> SA = U->getAddrOffsetSectionItem(Index);
640 return {{Value.uval, Value.SectionIndex}};
643 Optional<uint64_t> DWARFFormValue::getAsReference() const {
644 if (auto R = getAsRelativeReference())
645 return R->Unit ? R->Unit->getOffset() + R->Offset : R->Offset;
649 Optional<DWARFFormValue::UnitOffset> DWARFFormValue::getAsRelativeReference() const {
650 if (!isFormClass(FC_Reference))
657 case DW_FORM_ref_udata:
660 return UnitOffset{const_cast<DWARFUnit*>(U), Value.uval};
661 case DW_FORM_ref_addr:
662 case DW_FORM_ref_sig8:
663 case DW_FORM_GNU_ref_alt:
664 return UnitOffset{nullptr, Value.uval};
670 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const {
671 if (!isFormClass(FC_SectionOffset))
676 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const {
677 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) ||
678 Form == DW_FORM_sdata)
683 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const {
684 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) ||
685 (Form == DW_FORM_udata &&
686 uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval))
690 return int32_t(Value.uval);
692 return int16_t(Value.uval);
694 return int8_t(Value.uval);
702 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const {
703 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc) &&
704 Form != DW_FORM_data16)
706 return makeArrayRef(Value.data, Value.uval);
709 Optional<uint64_t> DWARFFormValue::getAsCStringOffset() const {
710 if (!isFormClass(FC_String) && Form == DW_FORM_string)
715 Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const {
716 if (!isFormClass(FC_Reference))