1 //===- tools/dsymutil/DwarfStreamer.cpp - Dwarf Streamer ------------------===//
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 "DwarfStreamer.h"
10 #include "CompileUnit.h"
11 #include "LinkUtils.h"
12 #include "MachOUtils.h"
13 #include "llvm/ADT/Triple.h"
14 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
15 #include "llvm/MC/MCTargetOptions.h"
16 #include "llvm/MC/MCTargetOptionsCommandFlags.inc"
17 #include "llvm/Support/LEB128.h"
18 #include "llvm/Support/TargetRegistry.h"
19 #include "llvm/Target/TargetMachine.h"
20 #include "llvm/Target/TargetOptions.h"
25 /// Retrieve the section named \a SecName in \a Obj.
27 /// To accommodate for platform discrepancies, the name passed should be
28 /// (for example) 'debug_info' to match either '__debug_info' or '.debug_info'.
29 /// This function will strip the initial platform-specific characters.
30 static Optional
<object::SectionRef
>
31 getSectionByName(const object::ObjectFile
&Obj
, StringRef SecName
) {
32 for (const object::SectionRef
&Section
: Obj
.sections()) {
33 StringRef SectionName
;
34 if (Expected
<StringRef
> NameOrErr
= Section
.getName())
35 SectionName
= *NameOrErr
;
37 consumeError(NameOrErr
.takeError());
39 SectionName
= SectionName
.substr(SectionName
.find_first_not_of("._"));
40 if (SectionName
!= SecName
)
47 bool DwarfStreamer::init(Triple TheTriple
) {
49 std::string TripleName
;
50 StringRef Context
= "dwarf streamer init";
53 const Target
*TheTarget
=
54 TargetRegistry::lookupTarget(TripleName
, TheTriple
, ErrorStr
);
56 return error(ErrorStr
, Context
);
57 TripleName
= TheTriple
.getTriple();
59 // Create all the MC Objects.
60 MRI
.reset(TheTarget
->createMCRegInfo(TripleName
));
62 return error(Twine("no register info for target ") + TripleName
, Context
);
64 MAI
.reset(TheTarget
->createMCAsmInfo(*MRI
, TripleName
));
66 return error("no asm info for target " + TripleName
, Context
);
68 MOFI
.reset(new MCObjectFileInfo
);
69 MC
.reset(new MCContext(MAI
.get(), MRI
.get(), MOFI
.get()));
70 MOFI
->InitMCObjectFileInfo(TheTriple
, /*PIC*/ false, *MC
);
72 MSTI
.reset(TheTarget
->createMCSubtargetInfo(TripleName
, "", ""));
74 return error("no subtarget info for target " + TripleName
, Context
);
76 MCTargetOptions MCOptions
= InitMCTargetOptionsFromFlags();
77 MAB
= TheTarget
->createMCAsmBackend(*MSTI
, *MRI
, MCOptions
);
79 return error("no asm backend for target " + TripleName
, Context
);
81 MII
.reset(TheTarget
->createMCInstrInfo());
83 return error("no instr info info for target " + TripleName
, Context
);
85 MCE
= TheTarget
->createMCCodeEmitter(*MII
, *MRI
, *MC
);
87 return error("no code emitter for target " + TripleName
, Context
);
89 switch (Options
.FileType
) {
90 case OutputFileType::Assembly
: {
91 MIP
= TheTarget
->createMCInstPrinter(TheTriple
, MAI
->getAssemblerDialect(),
93 MS
= TheTarget
->createAsmStreamer(
94 *MC
, std::make_unique
<formatted_raw_ostream
>(OutFile
), true, true, MIP
,
95 std::unique_ptr
<MCCodeEmitter
>(MCE
), std::unique_ptr
<MCAsmBackend
>(MAB
),
99 case OutputFileType::Object
: {
100 MS
= TheTarget
->createMCObjectStreamer(
101 TheTriple
, *MC
, std::unique_ptr
<MCAsmBackend
>(MAB
),
102 MAB
->createObjectWriter(OutFile
), std::unique_ptr
<MCCodeEmitter
>(MCE
),
103 *MSTI
, MCOptions
.MCRelaxAll
, MCOptions
.MCIncrementalLinkerCompatible
,
104 /*DWARFMustBeAtTheEnd*/ false);
110 return error("no object streamer for target " + TripleName
, Context
);
112 // Finally create the AsmPrinter we'll use to emit the DIEs.
113 TM
.reset(TheTarget
->createTargetMachine(TripleName
, "", "", TargetOptions(),
116 return error("no target machine for target " + TripleName
, Context
);
118 Asm
.reset(TheTarget
->createAsmPrinter(*TM
, std::unique_ptr
<MCStreamer
>(MS
)));
120 return error("no asm printer for target " + TripleName
, Context
);
122 RangesSectionSize
= 0;
125 FrameSectionSize
= 0;
130 bool DwarfStreamer::finish(const DebugMap
&DM
, SymbolMapTranslator
&T
) {
132 if (DM
.getTriple().isOSDarwin() && !DM
.getBinaryPath().empty() &&
133 Options
.FileType
== OutputFileType::Object
)
134 Result
= MachOUtils::generateDsymCompanion(DM
, T
, *MS
, OutFile
);
140 void DwarfStreamer::switchToDebugInfoSection(unsigned DwarfVersion
) {
141 MS
->SwitchSection(MOFI
->getDwarfInfoSection());
142 MC
->setDwarfVersion(DwarfVersion
);
145 /// Emit the compilation unit header for \p Unit in the debug_info section.
147 /// A Dwarf section header is encoded as:
148 /// uint32_t Unit length (omitting this field)
150 /// uint32_t Abbreviation table offset
151 /// uint8_t Address size
153 /// Leading to a total of 11 bytes.
154 void DwarfStreamer::emitCompileUnitHeader(CompileUnit
&Unit
) {
155 unsigned Version
= Unit
.getOrigUnit().getVersion();
156 switchToDebugInfoSection(Version
);
158 /// The start of the unit within its section.
159 Unit
.setLabelBegin(Asm
->createTempSymbol("cu_begin"));
160 Asm
->OutStreamer
->EmitLabel(Unit
.getLabelBegin());
162 // Emit size of content not including length itself. The size has already
163 // been computed in CompileUnit::computeOffsets(). Subtract 4 to that size to
164 // account for the length field.
165 Asm
->emitInt32(Unit
.getNextUnitOffset() - Unit
.getStartOffset() - 4);
166 Asm
->emitInt16(Version
);
168 // We share one abbreviations table across all units so it's always at the
169 // start of the section.
171 Asm
->emitInt8(Unit
.getOrigUnit().getAddressByteSize());
174 EmittedUnits
.push_back({Unit
.getUniqueID(), Unit
.getLabelBegin()});
177 /// Emit the \p Abbrevs array as the shared abbreviation table
178 /// for the linked Dwarf file.
179 void DwarfStreamer::emitAbbrevs(
180 const std::vector
<std::unique_ptr
<DIEAbbrev
>> &Abbrevs
,
181 unsigned DwarfVersion
) {
182 MS
->SwitchSection(MOFI
->getDwarfAbbrevSection());
183 MC
->setDwarfVersion(DwarfVersion
);
184 Asm
->emitDwarfAbbrevs(Abbrevs
);
187 /// Recursively emit the DIE tree rooted at \p Die.
188 void DwarfStreamer::emitDIE(DIE
&Die
) {
189 MS
->SwitchSection(MOFI
->getDwarfInfoSection());
190 Asm
->emitDwarfDIE(Die
);
193 /// Emit the debug_str section stored in \p Pool.
194 void DwarfStreamer::emitStrings(const NonRelocatableStringpool
&Pool
) {
195 Asm
->OutStreamer
->SwitchSection(MOFI
->getDwarfStrSection());
196 std::vector
<DwarfStringPoolEntryRef
> Entries
= Pool
.getEntriesForEmission();
197 for (auto Entry
: Entries
) {
198 // Emit the string itself.
199 Asm
->OutStreamer
->EmitBytes(Entry
.getString());
200 // Emit a null terminator.
205 void DwarfStreamer::emitDebugNames(
206 AccelTable
<DWARF5AccelTableStaticData
> &Table
) {
207 if (EmittedUnits
.empty())
210 // Build up data structures needed to emit this section.
211 std::vector
<MCSymbol
*> CompUnits
;
212 DenseMap
<unsigned, size_t> UniqueIdToCuMap
;
214 for (auto &CU
: EmittedUnits
) {
215 CompUnits
.push_back(CU
.LabelBegin
);
216 // We might be omitting CUs, so we need to remap them.
217 UniqueIdToCuMap
[CU
.ID
] = Id
++;
220 Asm
->OutStreamer
->SwitchSection(MOFI
->getDwarfDebugNamesSection());
221 emitDWARF5AccelTable(
222 Asm
.get(), Table
, CompUnits
,
223 [&UniqueIdToCuMap
](const DWARF5AccelTableStaticData
&Entry
) {
224 return UniqueIdToCuMap
[Entry
.getCUIndex()];
228 void DwarfStreamer::emitAppleNamespaces(
229 AccelTable
<AppleAccelTableStaticOffsetData
> &Table
) {
230 Asm
->OutStreamer
->SwitchSection(MOFI
->getDwarfAccelNamespaceSection());
231 auto *SectionBegin
= Asm
->createTempSymbol("namespac_begin");
232 Asm
->OutStreamer
->EmitLabel(SectionBegin
);
233 emitAppleAccelTable(Asm
.get(), Table
, "namespac", SectionBegin
);
236 void DwarfStreamer::emitAppleNames(
237 AccelTable
<AppleAccelTableStaticOffsetData
> &Table
) {
238 Asm
->OutStreamer
->SwitchSection(MOFI
->getDwarfAccelNamesSection());
239 auto *SectionBegin
= Asm
->createTempSymbol("names_begin");
240 Asm
->OutStreamer
->EmitLabel(SectionBegin
);
241 emitAppleAccelTable(Asm
.get(), Table
, "names", SectionBegin
);
244 void DwarfStreamer::emitAppleObjc(
245 AccelTable
<AppleAccelTableStaticOffsetData
> &Table
) {
246 Asm
->OutStreamer
->SwitchSection(MOFI
->getDwarfAccelObjCSection());
247 auto *SectionBegin
= Asm
->createTempSymbol("objc_begin");
248 Asm
->OutStreamer
->EmitLabel(SectionBegin
);
249 emitAppleAccelTable(Asm
.get(), Table
, "objc", SectionBegin
);
252 void DwarfStreamer::emitAppleTypes(
253 AccelTable
<AppleAccelTableStaticTypeData
> &Table
) {
254 Asm
->OutStreamer
->SwitchSection(MOFI
->getDwarfAccelTypesSection());
255 auto *SectionBegin
= Asm
->createTempSymbol("types_begin");
256 Asm
->OutStreamer
->EmitLabel(SectionBegin
);
257 emitAppleAccelTable(Asm
.get(), Table
, "types", SectionBegin
);
260 /// Emit the swift_ast section stored in \p Buffers.
261 void DwarfStreamer::emitSwiftAST(StringRef Buffer
) {
262 MCSection
*SwiftASTSection
= MOFI
->getDwarfSwiftASTSection();
263 SwiftASTSection
->setAlignment(Align(32));
264 MS
->SwitchSection(SwiftASTSection
);
265 MS
->EmitBytes(Buffer
);
268 /// Emit the debug_range section contents for \p FuncRange by
269 /// translating the original \p Entries. The debug_range section
270 /// format is totally trivial, consisting just of pairs of address
271 /// sized addresses describing the ranges.
272 void DwarfStreamer::emitRangesEntries(
273 int64_t UnitPcOffset
, uint64_t OrigLowPc
,
274 const FunctionIntervals::const_iterator
&FuncRange
,
275 const std::vector
<DWARFDebugRangeList::RangeListEntry
> &Entries
,
276 unsigned AddressSize
) {
277 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfRangesSection());
279 // Offset each range by the right amount.
280 int64_t PcOffset
= Entries
.empty() ? 0 : FuncRange
.value() + UnitPcOffset
;
281 for (const auto &Range
: Entries
) {
282 if (Range
.isBaseAddressSelectionEntry(AddressSize
)) {
283 warn("unsupported base address selection operation",
284 "emitting debug_ranges");
287 // Do not emit empty ranges.
288 if (Range
.StartAddress
== Range
.EndAddress
)
291 // All range entries should lie in the function range.
292 if (!(Range
.StartAddress
+ OrigLowPc
>= FuncRange
.start() &&
293 Range
.EndAddress
+ OrigLowPc
<= FuncRange
.stop()))
294 warn("inconsistent range data.", "emitting debug_ranges");
295 MS
->EmitIntValue(Range
.StartAddress
+ PcOffset
, AddressSize
);
296 MS
->EmitIntValue(Range
.EndAddress
+ PcOffset
, AddressSize
);
297 RangesSectionSize
+= 2 * AddressSize
;
300 // Add the terminator entry.
301 MS
->EmitIntValue(0, AddressSize
);
302 MS
->EmitIntValue(0, AddressSize
);
303 RangesSectionSize
+= 2 * AddressSize
;
306 /// Emit the debug_aranges contribution of a unit and
307 /// if \p DoDebugRanges is true the debug_range contents for a
308 /// compile_unit level DW_AT_ranges attribute (Which are basically the
309 /// same thing with a different base address).
310 /// Just aggregate all the ranges gathered inside that unit.
311 void DwarfStreamer::emitUnitRangesEntries(CompileUnit
&Unit
,
312 bool DoDebugRanges
) {
313 unsigned AddressSize
= Unit
.getOrigUnit().getAddressByteSize();
314 // Gather the ranges in a vector, so that we can simplify them. The
315 // IntervalMap will have coalesced the non-linked ranges, but here
316 // we want to coalesce the linked addresses.
317 std::vector
<std::pair
<uint64_t, uint64_t>> Ranges
;
318 const auto &FunctionRanges
= Unit
.getFunctionRanges();
319 for (auto Range
= FunctionRanges
.begin(), End
= FunctionRanges
.end();
320 Range
!= End
; ++Range
)
321 Ranges
.push_back(std::make_pair(Range
.start() + Range
.value(),
322 Range
.stop() + Range
.value()));
324 // The object addresses where sorted, but again, the linked
325 // addresses might end up in a different order.
328 if (!Ranges
.empty()) {
329 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfARangesSection());
331 MCSymbol
*BeginLabel
= Asm
->createTempSymbol("Barange");
332 MCSymbol
*EndLabel
= Asm
->createTempSymbol("Earange");
334 unsigned HeaderSize
=
335 sizeof(int32_t) + // Size of contents (w/o this field
336 sizeof(int16_t) + // DWARF ARange version number
337 sizeof(int32_t) + // Offset of CU in the .debug_info section
338 sizeof(int8_t) + // Pointer Size (in bytes)
339 sizeof(int8_t); // Segment Size (in bytes)
341 unsigned TupleSize
= AddressSize
* 2;
342 unsigned Padding
= offsetToAlignment(HeaderSize
, Align(TupleSize
));
344 Asm
->EmitLabelDifference(EndLabel
, BeginLabel
, 4); // Arange length
345 Asm
->OutStreamer
->EmitLabel(BeginLabel
);
346 Asm
->emitInt16(dwarf::DW_ARANGES_VERSION
); // Version number
347 Asm
->emitInt32(Unit
.getStartOffset()); // Corresponding unit's offset
348 Asm
->emitInt8(AddressSize
); // Address size
349 Asm
->emitInt8(0); // Segment size
351 Asm
->OutStreamer
->emitFill(Padding
, 0x0);
353 for (auto Range
= Ranges
.begin(), End
= Ranges
.end(); Range
!= End
;
355 uint64_t RangeStart
= Range
->first
;
356 MS
->EmitIntValue(RangeStart
, AddressSize
);
357 while ((Range
+ 1) != End
&& Range
->second
== (Range
+ 1)->first
)
359 MS
->EmitIntValue(Range
->second
- RangeStart
, AddressSize
);
363 Asm
->OutStreamer
->EmitIntValue(0, AddressSize
);
364 Asm
->OutStreamer
->EmitIntValue(0, AddressSize
);
365 Asm
->OutStreamer
->EmitLabel(EndLabel
);
371 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfRangesSection());
372 // Offset each range by the right amount.
373 int64_t PcOffset
= -Unit
.getLowPc();
374 // Emit coalesced ranges.
375 for (auto Range
= Ranges
.begin(), End
= Ranges
.end(); Range
!= End
; ++Range
) {
376 MS
->EmitIntValue(Range
->first
+ PcOffset
, AddressSize
);
377 while (Range
+ 1 != End
&& Range
->second
== (Range
+ 1)->first
)
379 MS
->EmitIntValue(Range
->second
+ PcOffset
, AddressSize
);
380 RangesSectionSize
+= 2 * AddressSize
;
383 // Add the terminator entry.
384 MS
->EmitIntValue(0, AddressSize
);
385 MS
->EmitIntValue(0, AddressSize
);
386 RangesSectionSize
+= 2 * AddressSize
;
389 /// Emit location lists for \p Unit and update attributes to point to the new
391 void DwarfStreamer::emitLocationsForUnit(
392 const CompileUnit
&Unit
, DWARFContext
&Dwarf
,
393 std::function
<void(StringRef
, SmallVectorImpl
<uint8_t> &)> ProcessExpr
) {
394 const auto &Attributes
= Unit
.getLocationAttributes();
396 if (Attributes
.empty())
399 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfLocSection());
401 unsigned AddressSize
= Unit
.getOrigUnit().getAddressByteSize();
402 uint64_t BaseAddressMarker
= (AddressSize
== 8)
403 ? std::numeric_limits
<uint64_t>::max()
404 : std::numeric_limits
<uint32_t>::max();
405 const DWARFSection
&InputSec
= Dwarf
.getDWARFObj().getLocSection();
406 DataExtractor
Data(InputSec
.Data
, Dwarf
.isLittleEndian(), AddressSize
);
407 DWARFUnit
&OrigUnit
= Unit
.getOrigUnit();
408 auto OrigUnitDie
= OrigUnit
.getUnitDIE(false);
409 int64_t UnitPcOffset
= 0;
410 if (auto OrigLowPc
= dwarf::toAddress(OrigUnitDie
.find(dwarf::DW_AT_low_pc
)))
411 UnitPcOffset
= int64_t(*OrigLowPc
) - Unit
.getLowPc();
413 SmallVector
<uint8_t, 32> Buffer
;
414 for (const auto &Attr
: Attributes
) {
415 uint64_t Offset
= Attr
.first
.get();
416 Attr
.first
.set(LocSectionSize
);
417 // This is the quantity to add to the old location address to get
418 // the correct address for the new one.
419 int64_t LocPcOffset
= Attr
.second
+ UnitPcOffset
;
420 while (Data
.isValidOffset(Offset
)) {
421 uint64_t Low
= Data
.getUnsigned(&Offset
, AddressSize
);
422 uint64_t High
= Data
.getUnsigned(&Offset
, AddressSize
);
423 LocSectionSize
+= 2 * AddressSize
;
424 // End of list entry.
425 if (Low
== 0 && High
== 0) {
426 Asm
->OutStreamer
->EmitIntValue(0, AddressSize
);
427 Asm
->OutStreamer
->EmitIntValue(0, AddressSize
);
430 // Base address selection entry.
431 if (Low
== BaseAddressMarker
) {
432 Asm
->OutStreamer
->EmitIntValue(BaseAddressMarker
, AddressSize
);
433 Asm
->OutStreamer
->EmitIntValue(High
+ Attr
.second
, AddressSize
);
437 // Location list entry.
438 Asm
->OutStreamer
->EmitIntValue(Low
+ LocPcOffset
, AddressSize
);
439 Asm
->OutStreamer
->EmitIntValue(High
+ LocPcOffset
, AddressSize
);
440 uint64_t Length
= Data
.getU16(&Offset
);
441 Asm
->OutStreamer
->EmitIntValue(Length
, 2);
442 // Copy the bytes into to the buffer, process them, emit them.
443 Buffer
.reserve(Length
);
445 StringRef Input
= InputSec
.Data
.substr(Offset
, Length
);
446 ProcessExpr(Input
, Buffer
);
447 Asm
->OutStreamer
->EmitBytes(
448 StringRef((const char *)Buffer
.data(), Length
));
450 LocSectionSize
+= Length
+ 2;
455 void DwarfStreamer::emitLineTableForUnit(MCDwarfLineTableParams Params
,
456 StringRef PrologueBytes
,
457 unsigned MinInstLength
,
458 std::vector
<DWARFDebugLine::Row
> &Rows
,
459 unsigned PointerSize
) {
460 // Switch to the section where the table will be emitted into.
461 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfLineSection());
462 MCSymbol
*LineStartSym
= MC
->createTempSymbol();
463 MCSymbol
*LineEndSym
= MC
->createTempSymbol();
465 // The first 4 bytes is the total length of the information for this
466 // compilation unit (not including these 4 bytes for the length).
467 Asm
->EmitLabelDifference(LineEndSym
, LineStartSym
, 4);
468 Asm
->OutStreamer
->EmitLabel(LineStartSym
);
470 MS
->EmitBytes(PrologueBytes
);
471 LineSectionSize
+= PrologueBytes
.size() + 4;
473 SmallString
<128> EncodingBuffer
;
474 raw_svector_ostream
EncodingOS(EncodingBuffer
);
477 // We only have the dummy entry, dsymutil emits an entry with a 0
478 // address in that case.
479 MCDwarfLineAddr::Encode(*MC
, Params
, std::numeric_limits
<int64_t>::max(), 0,
481 MS
->EmitBytes(EncodingOS
.str());
482 LineSectionSize
+= EncodingBuffer
.size();
483 MS
->EmitLabel(LineEndSym
);
487 // Line table state machine fields
488 unsigned FileNum
= 1;
489 unsigned LastLine
= 1;
491 unsigned IsStatement
= 1;
493 uint64_t Address
= -1ULL;
495 unsigned RowsSinceLastSequence
= 0;
497 for (unsigned Idx
= 0; Idx
< Rows
.size(); ++Idx
) {
498 auto &Row
= Rows
[Idx
];
500 int64_t AddressDelta
;
501 if (Address
== -1ULL) {
502 MS
->EmitIntValue(dwarf::DW_LNS_extended_op
, 1);
503 MS
->EmitULEB128IntValue(PointerSize
+ 1);
504 MS
->EmitIntValue(dwarf::DW_LNE_set_address
, 1);
505 MS
->EmitIntValue(Row
.Address
.Address
, PointerSize
);
506 LineSectionSize
+= 2 + PointerSize
+ getULEB128Size(PointerSize
+ 1);
509 AddressDelta
= (Row
.Address
.Address
- Address
) / MinInstLength
;
512 // FIXME: code copied and transformed from MCDwarf.cpp::EmitDwarfLineTable.
513 // We should find a way to share this code, but the current compatibility
514 // requirement with classic dsymutil makes it hard. Revisit that once this
515 // requirement is dropped.
517 if (FileNum
!= Row
.File
) {
519 MS
->EmitIntValue(dwarf::DW_LNS_set_file
, 1);
520 MS
->EmitULEB128IntValue(FileNum
);
521 LineSectionSize
+= 1 + getULEB128Size(FileNum
);
523 if (Column
!= Row
.Column
) {
525 MS
->EmitIntValue(dwarf::DW_LNS_set_column
, 1);
526 MS
->EmitULEB128IntValue(Column
);
527 LineSectionSize
+= 1 + getULEB128Size(Column
);
530 // FIXME: We should handle the discriminator here, but dsymutil doesn't
531 // consider it, thus ignore it for now.
533 if (Isa
!= Row
.Isa
) {
535 MS
->EmitIntValue(dwarf::DW_LNS_set_isa
, 1);
536 MS
->EmitULEB128IntValue(Isa
);
537 LineSectionSize
+= 1 + getULEB128Size(Isa
);
539 if (IsStatement
!= Row
.IsStmt
) {
540 IsStatement
= Row
.IsStmt
;
541 MS
->EmitIntValue(dwarf::DW_LNS_negate_stmt
, 1);
542 LineSectionSize
+= 1;
544 if (Row
.BasicBlock
) {
545 MS
->EmitIntValue(dwarf::DW_LNS_set_basic_block
, 1);
546 LineSectionSize
+= 1;
549 if (Row
.PrologueEnd
) {
550 MS
->EmitIntValue(dwarf::DW_LNS_set_prologue_end
, 1);
551 LineSectionSize
+= 1;
554 if (Row
.EpilogueBegin
) {
555 MS
->EmitIntValue(dwarf::DW_LNS_set_epilogue_begin
, 1);
556 LineSectionSize
+= 1;
559 int64_t LineDelta
= int64_t(Row
.Line
) - LastLine
;
560 if (!Row
.EndSequence
) {
561 MCDwarfLineAddr::Encode(*MC
, Params
, LineDelta
, AddressDelta
, EncodingOS
);
562 MS
->EmitBytes(EncodingOS
.str());
563 LineSectionSize
+= EncodingBuffer
.size();
564 EncodingBuffer
.resize(0);
565 Address
= Row
.Address
.Address
;
567 RowsSinceLastSequence
++;
570 MS
->EmitIntValue(dwarf::DW_LNS_advance_line
, 1);
571 MS
->EmitSLEB128IntValue(LineDelta
);
572 LineSectionSize
+= 1 + getSLEB128Size(LineDelta
);
575 MS
->EmitIntValue(dwarf::DW_LNS_advance_pc
, 1);
576 MS
->EmitULEB128IntValue(AddressDelta
);
577 LineSectionSize
+= 1 + getULEB128Size(AddressDelta
);
579 MCDwarfLineAddr::Encode(*MC
, Params
, std::numeric_limits
<int64_t>::max(),
581 MS
->EmitBytes(EncodingOS
.str());
582 LineSectionSize
+= EncodingBuffer
.size();
583 EncodingBuffer
.resize(0);
585 LastLine
= FileNum
= IsStatement
= 1;
586 RowsSinceLastSequence
= Column
= Isa
= 0;
590 if (RowsSinceLastSequence
) {
591 MCDwarfLineAddr::Encode(*MC
, Params
, std::numeric_limits
<int64_t>::max(), 0,
593 MS
->EmitBytes(EncodingOS
.str());
594 LineSectionSize
+= EncodingBuffer
.size();
595 EncodingBuffer
.resize(0);
598 MS
->EmitLabel(LineEndSym
);
601 /// Copy the debug_line over to the updated binary while unobfuscating the file
602 /// names and directories.
603 void DwarfStreamer::translateLineTable(DataExtractor Data
, uint64_t Offset
) {
604 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfLineSection());
605 StringRef Contents
= Data
.getData();
607 // We have to deconstruct the line table header, because it contains to
608 // length fields that will need to be updated when we change the length of
609 // the files and directories in there.
610 unsigned UnitLength
= Data
.getU32(&Offset
);
611 uint64_t UnitEnd
= Offset
+ UnitLength
;
612 MCSymbol
*BeginLabel
= MC
->createTempSymbol();
613 MCSymbol
*EndLabel
= MC
->createTempSymbol();
614 unsigned Version
= Data
.getU16(&Offset
);
617 warn("Unsupported line table version: dropping contents and not "
618 "unobfsucating line table.");
622 Asm
->EmitLabelDifference(EndLabel
, BeginLabel
, 4);
623 Asm
->OutStreamer
->EmitLabel(BeginLabel
);
624 Asm
->emitInt16(Version
);
625 LineSectionSize
+= 6;
627 MCSymbol
*HeaderBeginLabel
= MC
->createTempSymbol();
628 MCSymbol
*HeaderEndLabel
= MC
->createTempSymbol();
629 Asm
->EmitLabelDifference(HeaderEndLabel
, HeaderBeginLabel
, 4);
630 Asm
->OutStreamer
->EmitLabel(HeaderBeginLabel
);
632 LineSectionSize
+= 4;
634 uint64_t AfterHeaderLengthOffset
= Offset
;
635 // Skip to the directories.
636 Offset
+= (Version
>= 4) ? 5 : 4;
637 unsigned OpcodeBase
= Data
.getU8(&Offset
);
638 Offset
+= OpcodeBase
- 1;
639 Asm
->OutStreamer
->EmitBytes(Contents
.slice(AfterHeaderLengthOffset
, Offset
));
640 LineSectionSize
+= Offset
- AfterHeaderLengthOffset
;
642 // Offset points to the first directory.
643 while (const char *Dir
= Data
.getCStr(&Offset
)) {
647 StringRef Translated
= Options
.Translator(Dir
);
648 Asm
->OutStreamer
->EmitBytes(Translated
);
650 LineSectionSize
+= Translated
.size() + 1;
653 LineSectionSize
+= 1;
655 while (const char *File
= Data
.getCStr(&Offset
)) {
659 StringRef Translated
= Options
.Translator(File
);
660 Asm
->OutStreamer
->EmitBytes(Translated
);
662 LineSectionSize
+= Translated
.size() + 1;
664 uint64_t OffsetBeforeLEBs
= Offset
;
665 Asm
->EmitULEB128(Data
.getULEB128(&Offset
));
666 Asm
->EmitULEB128(Data
.getULEB128(&Offset
));
667 Asm
->EmitULEB128(Data
.getULEB128(&Offset
));
668 LineSectionSize
+= Offset
- OffsetBeforeLEBs
;
671 LineSectionSize
+= 1;
673 Asm
->OutStreamer
->EmitLabel(HeaderEndLabel
);
675 // Copy the actual line table program over.
676 Asm
->OutStreamer
->EmitBytes(Contents
.slice(Offset
, UnitEnd
));
677 LineSectionSize
+= UnitEnd
- Offset
;
679 Asm
->OutStreamer
->EmitLabel(EndLabel
);
683 static void emitSectionContents(const object::ObjectFile
&Obj
,
684 StringRef SecName
, MCStreamer
*MS
) {
685 if (auto Sec
= getSectionByName(Obj
, SecName
)) {
686 if (Expected
<StringRef
> E
= Sec
->getContents())
689 consumeError(E
.takeError());
693 void DwarfStreamer::copyInvariantDebugSection(const object::ObjectFile
&Obj
) {
694 if (!Options
.Translator
) {
695 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfLineSection());
696 emitSectionContents(Obj
, "debug_line", MS
);
699 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfLocSection());
700 emitSectionContents(Obj
, "debug_loc", MS
);
702 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfRangesSection());
703 emitSectionContents(Obj
, "debug_ranges", MS
);
705 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfFrameSection());
706 emitSectionContents(Obj
, "debug_frame", MS
);
708 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfARangesSection());
709 emitSectionContents(Obj
, "debug_aranges", MS
);
712 /// Emit the pubnames or pubtypes section contribution for \p
713 /// Unit into \p Sec. The data is provided in \p Names.
714 void DwarfStreamer::emitPubSectionForUnit(
715 MCSection
*Sec
, StringRef SecName
, const CompileUnit
&Unit
,
716 const std::vector
<CompileUnit::AccelInfo
> &Names
) {
720 // Start the dwarf pubnames section.
721 Asm
->OutStreamer
->SwitchSection(Sec
);
722 MCSymbol
*BeginLabel
= Asm
->createTempSymbol("pub" + SecName
+ "_begin");
723 MCSymbol
*EndLabel
= Asm
->createTempSymbol("pub" + SecName
+ "_end");
725 bool HeaderEmitted
= false;
726 // Emit the pubnames for this compilation unit.
727 for (const auto &Name
: Names
) {
728 if (Name
.SkipPubSection
)
731 if (!HeaderEmitted
) {
733 Asm
->EmitLabelDifference(EndLabel
, BeginLabel
, 4); // Length
734 Asm
->OutStreamer
->EmitLabel(BeginLabel
);
735 Asm
->emitInt16(dwarf::DW_PUBNAMES_VERSION
); // Version
736 Asm
->emitInt32(Unit
.getStartOffset()); // Unit offset
737 Asm
->emitInt32(Unit
.getNextUnitOffset() - Unit
.getStartOffset()); // Size
738 HeaderEmitted
= true;
740 Asm
->emitInt32(Name
.Die
->getOffset());
742 // Emit the string itself.
743 Asm
->OutStreamer
->EmitBytes(Name
.Name
.getString());
744 // Emit a null terminator.
750 Asm
->emitInt32(0); // End marker.
751 Asm
->OutStreamer
->EmitLabel(EndLabel
);
754 /// Emit .debug_pubnames for \p Unit.
755 void DwarfStreamer::emitPubNamesForUnit(const CompileUnit
&Unit
) {
756 emitPubSectionForUnit(MC
->getObjectFileInfo()->getDwarfPubNamesSection(),
757 "names", Unit
, Unit
.getPubnames());
760 /// Emit .debug_pubtypes for \p Unit.
761 void DwarfStreamer::emitPubTypesForUnit(const CompileUnit
&Unit
) {
762 emitPubSectionForUnit(MC
->getObjectFileInfo()->getDwarfPubTypesSection(),
763 "types", Unit
, Unit
.getPubtypes());
766 /// Emit a CIE into the debug_frame section.
767 void DwarfStreamer::emitCIE(StringRef CIEBytes
) {
768 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfFrameSection());
770 MS
->EmitBytes(CIEBytes
);
771 FrameSectionSize
+= CIEBytes
.size();
774 /// Emit a FDE into the debug_frame section. \p FDEBytes
775 /// contains the FDE data without the length, CIE offset and address
776 /// which will be replaced with the parameter values.
777 void DwarfStreamer::emitFDE(uint32_t CIEOffset
, uint32_t AddrSize
,
778 uint32_t Address
, StringRef FDEBytes
) {
779 MS
->SwitchSection(MC
->getObjectFileInfo()->getDwarfFrameSection());
781 MS
->EmitIntValue(FDEBytes
.size() + 4 + AddrSize
, 4);
782 MS
->EmitIntValue(CIEOffset
, 4);
783 MS
->EmitIntValue(Address
, AddrSize
);
784 MS
->EmitBytes(FDEBytes
);
785 FrameSectionSize
+= FDEBytes
.size() + 8 + AddrSize
;
788 } // namespace dsymutil