LLVM 19.0.0git
MachObjectWriter.cpp
Go to the documentation of this file.
1//===- lib/MC/MachObjectWriter.cpp - Mach-O File Writer -------------------===//
2//
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
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/ADT/DenseMap.h"
10#include "llvm/ADT/Twine.h"
14#include "llvm/MC/MCAsmLayout.h"
15#include "llvm/MC/MCAssembler.h"
16#include "llvm/MC/MCContext.h"
18#include "llvm/MC/MCExpr.h"
20#include "llvm/MC/MCFragment.h"
24#include "llvm/MC/MCSection.h"
26#include "llvm/MC/MCSymbol.h"
28#include "llvm/MC/MCValue.h"
31#include "llvm/Support/Debug.h"
33#include "llvm/Support/LEB128.h"
36#include <algorithm>
37#include <cassert>
38#include <cstdint>
39#include <string>
40#include <utility>
41#include <vector>
42
43using namespace llvm;
44
45#define DEBUG_TYPE "mc"
46
48 Relocations.clear();
49 IndirectSymBase.clear();
50 StringTable.clear();
51 LocalSymbolData.clear();
52 ExternalSymbolData.clear();
53 UndefinedSymbolData.clear();
55}
56
58 // Undefined symbols are always extern.
59 if (S.isUndefined())
60 return true;
61
62 // References to weak definitions require external relocation entries; the
63 // definition may not always be the one in the same object file.
64 if (cast<MCSymbolMachO>(S).isWeakDefinition())
65 return true;
66
67 // Otherwise, we can use an internal relocation.
68 return false;
69}
70
71bool MachObjectWriter::
72MachSymbolData::operator<(const MachSymbolData &RHS) const {
73 return Symbol->getName() < RHS.Symbol->getName();
74}
75
76bool MachObjectWriter::isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
77 const MCFixupKindInfo &FKI = Asm.getBackend().getFixupKindInfo(
78 (MCFixupKind) Kind);
79
81}
82
84 const MCAsmLayout &Layout) const {
85 return getSectionAddress(Fragment->getParent()) +
86 Layout.getFragmentOffset(Fragment);
87}
88
90 const MCAsmLayout &Layout) const {
91 // If this is a variable, then recursively evaluate now.
92 if (S.isVariable()) {
93 if (const MCConstantExpr *C =
94 dyn_cast<const MCConstantExpr>(S.getVariableValue()))
95 return C->getValue();
96
98 if (!S.getVariableValue()->evaluateAsRelocatable(Target, &Layout, nullptr))
99 report_fatal_error("unable to evaluate offset for variable '" +
100 S.getName() + "'");
101
102 // Verify that any used symbols are defined.
103 if (Target.getSymA() && Target.getSymA()->getSymbol().isUndefined())
104 report_fatal_error("unable to evaluate offset to undefined symbol '" +
105 Target.getSymA()->getSymbol().getName() + "'");
106 if (Target.getSymB() && Target.getSymB()->getSymbol().isUndefined())
107 report_fatal_error("unable to evaluate offset to undefined symbol '" +
108 Target.getSymB()->getSymbol().getName() + "'");
109
110 uint64_t Address = Target.getConstant();
111 if (Target.getSymA())
112 Address += getSymbolAddress(Target.getSymA()->getSymbol(), Layout);
113 if (Target.getSymB())
114 Address += getSymbolAddress(Target.getSymB()->getSymbol(), Layout);
115 return Address;
116 }
117
119 Layout.getSymbolOffset(S);
120}
121
123 const MCAsmLayout &Layout) const {
124 uint64_t EndAddr = getSectionAddress(Sec) + Layout.getSectionAddressSize(Sec);
125 unsigned Next = Sec->getLayoutOrder() + 1;
126 if (Next >= Layout.getSectionOrder().size())
127 return 0;
128
129 const MCSection &NextSec = *Layout.getSectionOrder()[Next];
130 if (NextSec.isVirtualSection())
131 return 0;
132 return offsetToAlignment(EndAddr, NextSec.getAlign());
133}
134
136 unsigned NumLoadCommands,
137 unsigned LoadCommandsSize,
138 bool SubsectionsViaSymbols) {
139 uint32_t Flags = 0;
140
141 if (SubsectionsViaSymbols)
143
144 // struct mach_header (28 bytes) or
145 // struct mach_header_64 (32 bytes)
146
147 uint64_t Start = W.OS.tell();
148 (void) Start;
149
151
152 W.write<uint32_t>(TargetObjectWriter->getCPUType());
153 W.write<uint32_t>(TargetObjectWriter->getCPUSubtype());
154
156 W.write<uint32_t>(NumLoadCommands);
157 W.write<uint32_t>(LoadCommandsSize);
158 W.write<uint32_t>(Flags);
159 if (is64Bit())
160 W.write<uint32_t>(0); // reserved
161
162 assert(W.OS.tell() - Start == (is64Bit() ? sizeof(MachO::mach_header_64)
163 : sizeof(MachO::mach_header)));
164}
165
166void MachObjectWriter::writeWithPadding(StringRef Str, uint64_t Size) {
167 assert(Size >= Str.size());
168 W.OS << Str;
169 W.OS.write_zeros(Size - Str.size());
170}
171
172/// writeSegmentLoadCommand - Write a segment load command.
173///
174/// \param NumSections The number of sections in this segment.
175/// \param SectionDataSize The total size of the sections.
177 StringRef Name, unsigned NumSections, uint64_t VMAddr, uint64_t VMSize,
178 uint64_t SectionDataStartOffset, uint64_t SectionDataSize, uint32_t MaxProt,
179 uint32_t InitProt) {
180 // struct segment_command (56 bytes) or
181 // struct segment_command_64 (72 bytes)
182
183 uint64_t Start = W.OS.tell();
184 (void) Start;
185
186 unsigned SegmentLoadCommandSize =
189 W.write<uint32_t>(is64Bit() ? MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT);
190 W.write<uint32_t>(SegmentLoadCommandSize +
191 NumSections * (is64Bit() ? sizeof(MachO::section_64) :
192 sizeof(MachO::section)));
193
194 writeWithPadding(Name, 16);
195 if (is64Bit()) {
196 W.write<uint64_t>(VMAddr); // vmaddr
197 W.write<uint64_t>(VMSize); // vmsize
198 W.write<uint64_t>(SectionDataStartOffset); // file offset
199 W.write<uint64_t>(SectionDataSize); // file size
200 } else {
201 W.write<uint32_t>(VMAddr); // vmaddr
202 W.write<uint32_t>(VMSize); // vmsize
203 W.write<uint32_t>(SectionDataStartOffset); // file offset
204 W.write<uint32_t>(SectionDataSize); // file size
205 }
206 // maxprot
207 W.write<uint32_t>(MaxProt);
208 // initprot
209 W.write<uint32_t>(InitProt);
210 W.write<uint32_t>(NumSections);
211 W.write<uint32_t>(0); // flags
212
213 assert(W.OS.tell() - Start == SegmentLoadCommandSize);
214}
215
217 const MCSection &Sec, uint64_t VMAddr,
218 uint64_t FileOffset, unsigned Flags,
219 uint64_t RelocationsStart,
220 unsigned NumRelocations) {
221 uint64_t SectionSize = Layout.getSectionAddressSize(&Sec);
222 const MCSectionMachO &Section = cast<MCSectionMachO>(Sec);
223
224 // The offset is unused for virtual sections.
225 if (Section.isVirtualSection()) {
226 assert(Layout.getSectionFileSize(&Sec) == 0 && "Invalid file size!");
227 FileOffset = 0;
228 }
229
230 // struct section (68 bytes) or
231 // struct section_64 (80 bytes)
232
233 uint64_t Start = W.OS.tell();
234 (void) Start;
235
236 writeWithPadding(Section.getName(), 16);
237 writeWithPadding(Section.getSegmentName(), 16);
238 if (is64Bit()) {
239 W.write<uint64_t>(VMAddr); // address
240 W.write<uint64_t>(SectionSize); // size
241 } else {
242 W.write<uint32_t>(VMAddr); // address
243 W.write<uint32_t>(SectionSize); // size
244 }
245 W.write<uint32_t>(FileOffset);
246
247 W.write<uint32_t>(Log2(Section.getAlign()));
248 W.write<uint32_t>(NumRelocations ? RelocationsStart : 0);
249 W.write<uint32_t>(NumRelocations);
250 W.write<uint32_t>(Flags);
251 W.write<uint32_t>(IndirectSymBase.lookup(&Sec)); // reserved1
252 W.write<uint32_t>(Section.getStubSize()); // reserved2
253 if (is64Bit())
254 W.write<uint32_t>(0); // reserved3
255
256 assert(W.OS.tell() - Start ==
257 (is64Bit() ? sizeof(MachO::section_64) : sizeof(MachO::section)));
258}
259
261 uint32_t NumSymbols,
262 uint32_t StringTableOffset,
263 uint32_t StringTableSize) {
264 // struct symtab_command (24 bytes)
265
266 uint64_t Start = W.OS.tell();
267 (void) Start;
268
269 W.write<uint32_t>(MachO::LC_SYMTAB);
271 W.write<uint32_t>(SymbolOffset);
272 W.write<uint32_t>(NumSymbols);
273 W.write<uint32_t>(StringTableOffset);
274 W.write<uint32_t>(StringTableSize);
275
276 assert(W.OS.tell() - Start == sizeof(MachO::symtab_command));
277}
278
280 uint32_t NumLocalSymbols,
281 uint32_t FirstExternalSymbol,
282 uint32_t NumExternalSymbols,
283 uint32_t FirstUndefinedSymbol,
284 uint32_t NumUndefinedSymbols,
285 uint32_t IndirectSymbolOffset,
286 uint32_t NumIndirectSymbols) {
287 // struct dysymtab_command (80 bytes)
288
289 uint64_t Start = W.OS.tell();
290 (void) Start;
291
292 W.write<uint32_t>(MachO::LC_DYSYMTAB);
294 W.write<uint32_t>(FirstLocalSymbol);
295 W.write<uint32_t>(NumLocalSymbols);
296 W.write<uint32_t>(FirstExternalSymbol);
297 W.write<uint32_t>(NumExternalSymbols);
298 W.write<uint32_t>(FirstUndefinedSymbol);
299 W.write<uint32_t>(NumUndefinedSymbols);
300 W.write<uint32_t>(0); // tocoff
301 W.write<uint32_t>(0); // ntoc
302 W.write<uint32_t>(0); // modtaboff
303 W.write<uint32_t>(0); // nmodtab
304 W.write<uint32_t>(0); // extrefsymoff
305 W.write<uint32_t>(0); // nextrefsyms
306 W.write<uint32_t>(IndirectSymbolOffset);
307 W.write<uint32_t>(NumIndirectSymbols);
308 W.write<uint32_t>(0); // extreloff
309 W.write<uint32_t>(0); // nextrel
310 W.write<uint32_t>(0); // locreloff
311 W.write<uint32_t>(0); // nlocrel
312
313 assert(W.OS.tell() - Start == sizeof(MachO::dysymtab_command));
314}
315
316MachObjectWriter::MachSymbolData *
317MachObjectWriter::findSymbolData(const MCSymbol &Sym) {
318 for (auto *SymbolData :
319 {&LocalSymbolData, &ExternalSymbolData, &UndefinedSymbolData})
320 for (MachSymbolData &Entry : *SymbolData)
321 if (Entry.Symbol == &Sym)
322 return &Entry;
323
324 return nullptr;
325}
326
328 const MCSymbol *S = &Sym;
329 while (S->isVariable()) {
330 const MCExpr *Value = S->getVariableValue();
331 const auto *Ref = dyn_cast<MCSymbolRefExpr>(Value);
332 if (!Ref)
333 return *S;
334 S = &Ref->getSymbol();
335 }
336 return *S;
337}
338
339void MachObjectWriter::writeNlist(MachSymbolData &MSD,
340 const MCAsmLayout &Layout) {
341 const MCSymbol *Symbol = MSD.Symbol;
342 const MCSymbol &Data = *Symbol;
343 const MCSymbol *AliasedSymbol = &findAliasedSymbol(*Symbol);
344 uint8_t SectionIndex = MSD.SectionIndex;
345 uint8_t Type = 0;
346 uint64_t Address = 0;
347 bool IsAlias = Symbol != AliasedSymbol;
348
349 const MCSymbol &OrigSymbol = *Symbol;
350 MachSymbolData *AliaseeInfo;
351 if (IsAlias) {
352 AliaseeInfo = findSymbolData(*AliasedSymbol);
353 if (AliaseeInfo)
354 SectionIndex = AliaseeInfo->SectionIndex;
355 Symbol = AliasedSymbol;
356 // FIXME: Should this update Data as well?
357 }
358
359 // Set the N_TYPE bits. See <mach-o/nlist.h>.
360 //
361 // FIXME: Are the prebound or indirect fields possible here?
362 if (IsAlias && Symbol->isUndefined())
364 else if (Symbol->isUndefined())
366 else if (Symbol->isAbsolute())
368 else
370
371 // FIXME: Set STAB bits.
372
373 if (Data.isPrivateExtern())
375
376 // Set external bit.
377 if (Data.isExternal() || (!IsAlias && Symbol->isUndefined()))
379
380 // Compute the symbol address.
381 if (IsAlias && Symbol->isUndefined())
382 Address = AliaseeInfo->StringIndex;
383 else if (Symbol->isDefined())
384 Address = getSymbolAddress(OrigSymbol, Layout);
385 else if (Symbol->isCommon()) {
386 // Common symbols are encoded with the size in the address
387 // field, and their alignment in the flags.
388 Address = Symbol->getCommonSize();
389 }
390
391 // struct nlist (12 bytes)
392
393 W.write<uint32_t>(MSD.StringIndex);
394 W.OS << char(Type);
395 W.OS << char(SectionIndex);
396
397 // The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc'
398 // value.
399 bool EncodeAsAltEntry =
400 IsAlias && cast<MCSymbolMachO>(OrigSymbol).isAltEntry();
401 W.write<uint16_t>(cast<MCSymbolMachO>(Symbol)->getEncodedFlags(EncodeAsAltEntry));
402 if (is64Bit())
404 else
406}
407
409 uint32_t DataOffset,
410 uint32_t DataSize) {
411 uint64_t Start = W.OS.tell();
412 (void) Start;
413
416 W.write<uint32_t>(DataOffset);
417 W.write<uint32_t>(DataSize);
418
419 assert(W.OS.tell() - Start == sizeof(MachO::linkedit_data_command));
420}
421
423 const std::vector<std::string> &Options, bool is64Bit)
424{
425 unsigned Size = sizeof(MachO::linker_option_command);
426 for (const std::string &Option : Options)
427 Size += Option.size() + 1;
428 return alignTo(Size, is64Bit ? 8 : 4);
429}
430
432 const std::vector<std::string> &Options)
433{
435 uint64_t Start = W.OS.tell();
436 (void) Start;
437
438 W.write<uint32_t>(MachO::LC_LINKER_OPTION);
440 W.write<uint32_t>(Options.size());
441 uint64_t BytesWritten = sizeof(MachO::linker_option_command);
442 for (const std::string &Option : Options) {
443 // Write each string, including the null byte.
444 W.OS << Option << '\0';
445 BytesWritten += Option.size() + 1;
446 }
447
448 // Pad to a multiple of the pointer size.
450 offsetToAlignment(BytesWritten, is64Bit() ? Align(8) : Align(4)));
451
452 assert(W.OS.tell() - Start == Size);
453}
454
455static bool isFixupTargetValid(const MCValue &Target) {
456 // Target is (LHS - RHS + cst).
457 // We don't support the form where LHS is null: -RHS + cst
458 if (!Target.getSymA() && Target.getSymB())
459 return false;
460 return true;
461}
462
464 const MCAsmLayout &Layout,
465 const MCFragment *Fragment,
466 const MCFixup &Fixup, MCValue Target,
467 uint64_t &FixedValue) {
469 Asm.getContext().reportError(Fixup.getLoc(),
470 "unsupported relocation expression");
471 return;
472 }
473
474 TargetObjectWriter->recordRelocation(this, Asm, Layout, Fragment, Fixup,
475 Target, FixedValue);
476}
477
479 // This is the point where 'as' creates actual symbols for indirect symbols
480 // (in the following two passes). It would be easier for us to do this sooner
481 // when we see the attribute, but that makes getting the order in the symbol
482 // table much more complicated than it is worth.
483 //
484 // FIXME: Revisit this when the dust settles.
485
486 // Report errors for use of .indirect_symbol not in a symbol pointer section
487 // or stub section.
488 for (IndirectSymbolData &ISD : llvm::make_range(Asm.indirect_symbol_begin(),
489 Asm.indirect_symbol_end())) {
490 const MCSectionMachO &Section = cast<MCSectionMachO>(*ISD.Section);
491
492 if (Section.getType() != MachO::S_NON_LAZY_SYMBOL_POINTERS &&
493 Section.getType() != MachO::S_LAZY_SYMBOL_POINTERS &&
494 Section.getType() != MachO::S_THREAD_LOCAL_VARIABLE_POINTERS &&
495 Section.getType() != MachO::S_SYMBOL_STUBS) {
496 MCSymbol &Symbol = *ISD.Symbol;
497 report_fatal_error("indirect symbol '" + Symbol.getName() +
498 "' not in a symbol pointer or stub section");
499 }
500 }
501
502 // Bind non-lazy symbol pointers first.
503 unsigned IndirectIndex = 0;
504 for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
505 ie = Asm.indirect_symbol_end(); it != ie; ++it, ++IndirectIndex) {
506 const MCSectionMachO &Section = cast<MCSectionMachO>(*it->Section);
507
508 if (Section.getType() != MachO::S_NON_LAZY_SYMBOL_POINTERS &&
509 Section.getType() != MachO::S_THREAD_LOCAL_VARIABLE_POINTERS)
510 continue;
511
512 // Initialize the section indirect symbol base, if necessary.
513 IndirectSymBase.insert(std::make_pair(it->Section, IndirectIndex));
514
515 Asm.registerSymbol(*it->Symbol);
516 }
517
518 // Then lazy symbol pointers and symbol stubs.
519 IndirectIndex = 0;
520 for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
521 ie = Asm.indirect_symbol_end(); it != ie; ++it, ++IndirectIndex) {
522 const MCSectionMachO &Section = cast<MCSectionMachO>(*it->Section);
523
524 if (Section.getType() != MachO::S_LAZY_SYMBOL_POINTERS &&
525 Section.getType() != MachO::S_SYMBOL_STUBS)
526 continue;
527
528 // Initialize the section indirect symbol base, if necessary.
529 IndirectSymBase.insert(std::make_pair(it->Section, IndirectIndex));
530
531 // Set the symbol type to undefined lazy, but only on construction.
532 //
533 // FIXME: Do not hardcode.
534 if (Asm.registerSymbol(*it->Symbol))
535 cast<MCSymbolMachO>(it->Symbol)->setReferenceTypeUndefinedLazy(true);
536 }
537}
538
539/// computeSymbolTable - Compute the symbol table data
541 MCAssembler &Asm, std::vector<MachSymbolData> &LocalSymbolData,
542 std::vector<MachSymbolData> &ExternalSymbolData,
543 std::vector<MachSymbolData> &UndefinedSymbolData) {
544 // Build section lookup table.
546 unsigned Index = 1;
547 for (MCAssembler::iterator it = Asm.begin(),
548 ie = Asm.end(); it != ie; ++it, ++Index)
549 SectionIndexMap[&*it] = Index;
550 assert(Index <= 256 && "Too many sections!");
551
552 // Build the string table.
553 for (const MCSymbol &Symbol : Asm.symbols()) {
554 if (!Asm.isSymbolLinkerVisible(Symbol))
555 continue;
556
557 StringTable.add(Symbol.getName());
558 }
559 StringTable.finalize();
560
561 // Build the symbol arrays but only for non-local symbols.
562 //
563 // The particular order that we collect and then sort the symbols is chosen to
564 // match 'as'. Even though it doesn't matter for correctness, this is
565 // important for letting us diff .o files.
566 for (const MCSymbol &Symbol : Asm.symbols()) {
567 // Ignore non-linker visible symbols.
568 if (!Asm.isSymbolLinkerVisible(Symbol))
569 continue;
570
571 if (!Symbol.isExternal() && !Symbol.isUndefined())
572 continue;
573
574 MachSymbolData MSD;
575 MSD.Symbol = &Symbol;
576 MSD.StringIndex = StringTable.getOffset(Symbol.getName());
577
578 if (Symbol.isUndefined()) {
579 MSD.SectionIndex = 0;
580 UndefinedSymbolData.push_back(MSD);
581 } else if (Symbol.isAbsolute()) {
582 MSD.SectionIndex = 0;
583 ExternalSymbolData.push_back(MSD);
584 } else {
585 MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
586 assert(MSD.SectionIndex && "Invalid section index!");
587 ExternalSymbolData.push_back(MSD);
588 }
589 }
590
591 // Now add the data for local symbols.
592 for (const MCSymbol &Symbol : Asm.symbols()) {
593 // Ignore non-linker visible symbols.
594 if (!Asm.isSymbolLinkerVisible(Symbol))
595 continue;
596
597 if (Symbol.isExternal() || Symbol.isUndefined())
598 continue;
599
600 MachSymbolData MSD;
601 MSD.Symbol = &Symbol;
602 MSD.StringIndex = StringTable.getOffset(Symbol.getName());
603
604 if (Symbol.isAbsolute()) {
605 MSD.SectionIndex = 0;
606 LocalSymbolData.push_back(MSD);
607 } else {
608 MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
609 assert(MSD.SectionIndex && "Invalid section index!");
610 LocalSymbolData.push_back(MSD);
611 }
612 }
613
614 // External and undefined symbols are required to be in lexicographic order.
615 llvm::sort(ExternalSymbolData);
616 llvm::sort(UndefinedSymbolData);
617
618 // Set the symbol indices.
619 Index = 0;
620 for (auto *SymbolData :
621 {&LocalSymbolData, &ExternalSymbolData, &UndefinedSymbolData})
622 for (MachSymbolData &Entry : *SymbolData)
623 Entry.Symbol->setIndex(Index++);
624
625 for (const MCSection &Section : Asm) {
626 for (RelAndSymbol &Rel : Relocations[&Section]) {
627 if (!Rel.Sym)
628 continue;
629
630 // Set the Index and the IsExtern bit.
631 unsigned Index = Rel.Sym->getIndex();
632 assert(isInt<24>(Index));
634 Rel.MRE.r_word1 = (Rel.MRE.r_word1 & (~0U << 24)) | Index | (1 << 27);
635 else
636 Rel.MRE.r_word1 = (Rel.MRE.r_word1 & 0xff) | Index << 8 | (1 << 4);
637 }
638 }
639}
640
642 const MCAsmLayout &Layout) {
643 uint64_t StartAddress = 0;
644 for (const MCSection *Sec : Layout.getSectionOrder()) {
645 StartAddress = alignTo(StartAddress, Sec->getAlign());
646 SectionAddress[Sec] = StartAddress;
647 StartAddress += Layout.getSectionAddressSize(Sec);
648
649 // Explicitly pad the section to match the alignment requirements of the
650 // following one. This is for 'gas' compatibility, it shouldn't
651 /// strictly be necessary.
652 StartAddress += getPaddingSize(Sec, Layout);
653 }
654}
655
657 const MCAsmLayout &Layout) {
658 computeSectionAddresses(Asm, Layout);
659
660 // Create symbol data for any indirect symbols.
662}
663
665 const MCAssembler &Asm, const MCSymbol &A, const MCSymbol &B,
666 bool InSet) const {
667 // FIXME: We don't handle things like
668 // foo = .
669 // creating atoms.
670 if (A.isVariable() || B.isVariable())
671 return false;
673 InSet);
674}
675
677 const MCAssembler &Asm, const MCSymbol &SymA, const MCFragment &FB,
678 bool InSet, bool IsPCRel) const {
679 if (InSet)
680 return true;
681
682 // The effective address is
683 // addr(atom(A)) + offset(A)
684 // - addr(atom(B)) - offset(B)
685 // and the offsets are not relocatable, so the fixup is fully resolved when
686 // addr(atom(A)) - addr(atom(B)) == 0.
687 const MCSymbol &SA = findAliasedSymbol(SymA);
688 const MCSection &SecA = SA.getSection();
689 const MCSection &SecB = *FB.getParent();
690
691 if (IsPCRel) {
692 // The simple (Darwin, except on x86_64) way of dealing with this was to
693 // assume that any reference to a temporary symbol *must* be a temporary
694 // symbol in the same atom, unless the sections differ. Therefore, any PCrel
695 // relocation to a temporary symbol (in the same section) is fully
696 // resolved. This also works in conjunction with absolutized .set, which
697 // requires the compiler to use .set to absolutize the differences between
698 // symbols which the compiler knows to be assembly time constants, so we
699 // don't need to worry about considering symbol differences fully resolved.
700 //
701 // If the file isn't using sub-sections-via-symbols, we can make the
702 // same assumptions about any symbol that we normally make about
703 // assembler locals.
704
705 bool hasReliableSymbolDifference = isX86_64();
706 if (!hasReliableSymbolDifference) {
707 if (!SA.isInSection() || &SecA != &SecB ||
708 (!SA.isTemporary() && FB.getAtom() != SA.getFragment()->getAtom() &&
709 Asm.getSubsectionsViaSymbols()))
710 return false;
711 return true;
712 }
713 }
714
715 // If they are not in the same section, we can't compute the diff.
716 if (&SecA != &SecB)
717 return false;
718
719 const MCFragment *FA = SA.getFragment();
720
721 // Bail if the symbol has no fragment.
722 if (!FA)
723 return false;
724
725 // If the atoms are the same, they are guaranteed to have the same address.
726 if (FA->getAtom() == FB.getAtom())
727 return true;
728
729 // Otherwise, we can't prove this is fully resolved.
730 return false;
731}
732
734 switch (Type) {
735 case MCVM_OSXVersionMin: return MachO::LC_VERSION_MIN_MACOSX;
736 case MCVM_IOSVersionMin: return MachO::LC_VERSION_MIN_IPHONEOS;
737 case MCVM_TvOSVersionMin: return MachO::LC_VERSION_MIN_TVOS;
738 case MCVM_WatchOSVersionMin: return MachO::LC_VERSION_MIN_WATCHOS;
739 }
740 llvm_unreachable("Invalid mc version min type");
741}
742
744 MCSection *AddrSigSection =
745 Asm.getContext().getObjectFileInfo()->getAddrSigSection();
746 unsigned Log2Size = is64Bit() ? 3 : 2;
747 for (const MCSymbol *S : getAddrsigSyms()) {
748 if (!S->isRegistered())
749 continue;
751 MRE.r_word0 = 0;
752 MRE.r_word1 = (Log2Size << 25) | (MachO::GENERIC_RELOC_VANILLA << 28);
753 addRelocation(S, AddrSigSection, MRE);
754 }
755}
756
758 const MCAsmLayout &Layout) {
759 uint64_t StartOffset = W.OS.tell();
760
762
763 // Compute symbol table information and bind symbol indices.
764 computeSymbolTable(Asm, LocalSymbolData, ExternalSymbolData,
765 UndefinedSymbolData);
766
767 if (!Asm.CGProfile.empty()) {
768 MCSection *CGProfileSection = Asm.getContext().getMachOSection(
769 "__LLVM", "__cg_profile", 0, SectionKind::getMetadata());
770 MCDataFragment *Frag = dyn_cast_or_null<MCDataFragment>(
771 &*CGProfileSection->getFragmentList().begin());
772 assert(Frag && "call graph profile section not reserved");
773 Frag->getContents().clear();
775 for (const MCAssembler::CGProfileEntry &CGPE : Asm.CGProfile) {
776 uint32_t FromIndex = CGPE.From->getSymbol().getIndex();
777 uint32_t ToIndex = CGPE.To->getSymbol().getIndex();
778 support::endian::write(OS, FromIndex, W.Endian);
781 }
782 }
783
784 unsigned NumSections = Asm.size();
785 const MCAssembler::VersionInfoType &VersionInfo =
786 Layout.getAssembler().getVersionInfo();
787
788 // The section data starts after the header, the segment load command (and
789 // section headers) and the symbol table.
790 unsigned NumLoadCommands = 1;
791 uint64_t LoadCommandsSize = is64Bit() ?
792 sizeof(MachO::segment_command_64) + NumSections * sizeof(MachO::section_64):
793 sizeof(MachO::segment_command) + NumSections * sizeof(MachO::section);
794
795 // Add the deployment target version info load command size, if used.
796 if (VersionInfo.Major != 0) {
797 ++NumLoadCommands;
798 if (VersionInfo.EmitBuildVersion)
799 LoadCommandsSize += sizeof(MachO::build_version_command);
800 else
801 LoadCommandsSize += sizeof(MachO::version_min_command);
802 }
803
804 const MCAssembler::VersionInfoType &TargetVariantVersionInfo =
806
807 // Add the target variant version info load command size, if used.
808 if (TargetVariantVersionInfo.Major != 0) {
809 ++NumLoadCommands;
810 assert(TargetVariantVersionInfo.EmitBuildVersion &&
811 "target variant should use build version");
812 LoadCommandsSize += sizeof(MachO::build_version_command);
813 }
814
815 // Add the data-in-code load command size, if used.
816 unsigned NumDataRegions = Asm.getDataRegions().size();
817 if (NumDataRegions) {
818 ++NumLoadCommands;
819 LoadCommandsSize += sizeof(MachO::linkedit_data_command);
820 }
821
822 // Add the loh load command size, if used.
823 uint64_t LOHRawSize = Asm.getLOHContainer().getEmitSize(*this, Layout);
824 uint64_t LOHSize = alignTo(LOHRawSize, is64Bit() ? 8 : 4);
825 if (LOHSize) {
826 ++NumLoadCommands;
827 LoadCommandsSize += sizeof(MachO::linkedit_data_command);
828 }
829
830 // Add the symbol table load command sizes, if used.
831 unsigned NumSymbols = LocalSymbolData.size() + ExternalSymbolData.size() +
832 UndefinedSymbolData.size();
833 if (NumSymbols) {
834 NumLoadCommands += 2;
835 LoadCommandsSize += (sizeof(MachO::symtab_command) +
837 }
838
839 // Add the linker option load commands sizes.
840 for (const auto &Option : Asm.getLinkerOptions()) {
841 ++NumLoadCommands;
842 LoadCommandsSize += ComputeLinkerOptionsLoadCommandSize(Option, is64Bit());
843 }
844
845 // Compute the total size of the section data, as well as its file size and vm
846 // size.
847 uint64_t SectionDataStart = (is64Bit() ? sizeof(MachO::mach_header_64) :
848 sizeof(MachO::mach_header)) + LoadCommandsSize;
849 uint64_t SectionDataSize = 0;
850 uint64_t SectionDataFileSize = 0;
851 uint64_t VMSize = 0;
852 for (const MCSection &Sec : Asm) {
854 uint64_t Size = Layout.getSectionAddressSize(&Sec);
855 uint64_t FileSize = Layout.getSectionFileSize(&Sec);
856 FileSize += getPaddingSize(&Sec, Layout);
857
858 VMSize = std::max(VMSize, Address + Size);
859
860 if (Sec.isVirtualSection())
861 continue;
862
863 SectionDataSize = std::max(SectionDataSize, Address + Size);
864 SectionDataFileSize = std::max(SectionDataFileSize, Address + FileSize);
865 }
866
867 // The section data is padded to pointer size bytes.
868 //
869 // FIXME: Is this machine dependent?
870 unsigned SectionDataPadding =
871 offsetToAlignment(SectionDataFileSize, is64Bit() ? Align(8) : Align(4));
872 SectionDataFileSize += SectionDataPadding;
873
874 // Write the prolog, starting with the header and load command...
875 writeHeader(MachO::MH_OBJECT, NumLoadCommands, LoadCommandsSize,
876 Asm.getSubsectionsViaSymbols());
877 uint32_t Prot =
879 writeSegmentLoadCommand("", NumSections, 0, VMSize, SectionDataStart,
880 SectionDataSize, Prot, Prot);
881
882 // ... and then the section headers.
883 uint64_t RelocTableEnd = SectionDataStart + SectionDataFileSize;
884 for (const MCSection &Section : Asm) {
885 const auto &Sec = cast<MCSectionMachO>(Section);
886 std::vector<RelAndSymbol> &Relocs = Relocations[&Sec];
887 unsigned NumRelocs = Relocs.size();
888 uint64_t SectionStart = SectionDataStart + getSectionAddress(&Sec);
889 unsigned Flags = Sec.getTypeAndAttributes();
890 if (Sec.hasInstructions())
892 writeSection(Layout, Sec, getSectionAddress(&Sec), SectionStart, Flags,
893 RelocTableEnd, NumRelocs);
894 RelocTableEnd += NumRelocs * sizeof(MachO::any_relocation_info);
895 }
896
897 // Write out the deployment target information, if it's available.
898 auto EmitDeploymentTargetVersion =
899 [&](const MCAssembler::VersionInfoType &VersionInfo) {
900 auto EncodeVersion = [](VersionTuple V) -> uint32_t {
901 assert(!V.empty() && "empty version");
902 unsigned Update = V.getSubminor().value_or(0);
903 unsigned Minor = V.getMinor().value_or(0);
904 assert(Update < 256 && "unencodable update target version");
905 assert(Minor < 256 && "unencodable minor target version");
906 assert(V.getMajor() < 65536 && "unencodable major target version");
907 return Update | (Minor << 8) | (V.getMajor() << 16);
908 };
909 uint32_t EncodedVersion = EncodeVersion(VersionTuple(
910 VersionInfo.Major, VersionInfo.Minor, VersionInfo.Update));
911 uint32_t SDKVersion = !VersionInfo.SDKVersion.empty()
912 ? EncodeVersion(VersionInfo.SDKVersion)
913 : 0;
914 if (VersionInfo.EmitBuildVersion) {
915 // FIXME: Currently empty tools. Add clang version in the future.
916 W.write<uint32_t>(MachO::LC_BUILD_VERSION);
918 W.write<uint32_t>(VersionInfo.TypeOrPlatform.Platform);
919 W.write<uint32_t>(EncodedVersion);
920 W.write<uint32_t>(SDKVersion);
921 W.write<uint32_t>(0); // Empty tools list.
922 } else {
924 getLCFromMCVM(VersionInfo.TypeOrPlatform.Type);
925 W.write<uint32_t>(LCType);
927 W.write<uint32_t>(EncodedVersion);
928 W.write<uint32_t>(SDKVersion);
929 }
930 };
931 if (VersionInfo.Major != 0)
932 EmitDeploymentTargetVersion(VersionInfo);
933 if (TargetVariantVersionInfo.Major != 0)
934 EmitDeploymentTargetVersion(TargetVariantVersionInfo);
935
936 // Write the data-in-code load command, if used.
937 uint64_t DataInCodeTableEnd = RelocTableEnd + NumDataRegions * 8;
938 if (NumDataRegions) {
939 uint64_t DataRegionsOffset = RelocTableEnd;
940 uint64_t DataRegionsSize = NumDataRegions * 8;
941 writeLinkeditLoadCommand(MachO::LC_DATA_IN_CODE, DataRegionsOffset,
942 DataRegionsSize);
943 }
944
945 // Write the loh load command, if used.
946 uint64_t LOHTableEnd = DataInCodeTableEnd + LOHSize;
947 if (LOHSize)
948 writeLinkeditLoadCommand(MachO::LC_LINKER_OPTIMIZATION_HINT,
949 DataInCodeTableEnd, LOHSize);
950
951 // Write the symbol table load command, if used.
952 if (NumSymbols) {
953 unsigned FirstLocalSymbol = 0;
954 unsigned NumLocalSymbols = LocalSymbolData.size();
955 unsigned FirstExternalSymbol = FirstLocalSymbol + NumLocalSymbols;
956 unsigned NumExternalSymbols = ExternalSymbolData.size();
957 unsigned FirstUndefinedSymbol = FirstExternalSymbol + NumExternalSymbols;
958 unsigned NumUndefinedSymbols = UndefinedSymbolData.size();
959 unsigned NumIndirectSymbols = Asm.indirect_symbol_size();
960 unsigned NumSymTabSymbols =
961 NumLocalSymbols + NumExternalSymbols + NumUndefinedSymbols;
962 uint64_t IndirectSymbolSize = NumIndirectSymbols * 4;
963 uint64_t IndirectSymbolOffset = 0;
964
965 // If used, the indirect symbols are written after the section data.
966 if (NumIndirectSymbols)
967 IndirectSymbolOffset = LOHTableEnd;
968
969 // The symbol table is written after the indirect symbol data.
970 uint64_t SymbolTableOffset = LOHTableEnd + IndirectSymbolSize;
971
972 // The string table is written after symbol table.
973 uint64_t StringTableOffset =
974 SymbolTableOffset + NumSymTabSymbols * (is64Bit() ?
975 sizeof(MachO::nlist_64) :
976 sizeof(MachO::nlist));
977 writeSymtabLoadCommand(SymbolTableOffset, NumSymTabSymbols,
978 StringTableOffset, StringTable.getSize());
979
980 writeDysymtabLoadCommand(FirstLocalSymbol, NumLocalSymbols,
981 FirstExternalSymbol, NumExternalSymbols,
982 FirstUndefinedSymbol, NumUndefinedSymbols,
983 IndirectSymbolOffset, NumIndirectSymbols);
984 }
985
986 // Write the linker options load commands.
987 for (const auto &Option : Asm.getLinkerOptions())
989
990 // Write the actual section data.
991 for (const MCSection &Sec : Asm) {
992 Asm.writeSectionData(W.OS, &Sec, Layout);
993
994 uint64_t Pad = getPaddingSize(&Sec, Layout);
995 W.OS.write_zeros(Pad);
996 }
997
998 // Write the extra padding.
999 W.OS.write_zeros(SectionDataPadding);
1000
1001 // Write the relocation entries.
1002 for (const MCSection &Sec : Asm) {
1003 // Write the section relocation entries, in reverse order to match 'as'
1004 // (approximately, the exact algorithm is more complicated than this).
1005 std::vector<RelAndSymbol> &Relocs = Relocations[&Sec];
1006 for (const RelAndSymbol &Rel : llvm::reverse(Relocs)) {
1007 W.write<uint32_t>(Rel.MRE.r_word0);
1008 W.write<uint32_t>(Rel.MRE.r_word1);
1009 }
1010 }
1011
1012 // Write out the data-in-code region payload, if there is one.
1014 it = Asm.data_region_begin(), ie = Asm.data_region_end();
1015 it != ie; ++it) {
1016 const DataRegionData *Data = &(*it);
1017 uint64_t Start = getSymbolAddress(*Data->Start, Layout);
1018 uint64_t End;
1019 if (Data->End)
1020 End = getSymbolAddress(*Data->End, Layout);
1021 else
1022 report_fatal_error("Data region not terminated");
1023
1024 LLVM_DEBUG(dbgs() << "data in code region-- kind: " << Data->Kind
1025 << " start: " << Start << "(" << Data->Start->getName()
1026 << ")"
1027 << " end: " << End << "(" << Data->End->getName() << ")"
1028 << " size: " << End - Start << "\n");
1029 W.write<uint32_t>(Start);
1030 W.write<uint16_t>(End - Start);
1031 W.write<uint16_t>(Data->Kind);
1032 }
1033
1034 // Write out the loh commands, if there is one.
1035 if (LOHSize) {
1036#ifndef NDEBUG
1037 unsigned Start = W.OS.tell();
1038#endif
1039 Asm.getLOHContainer().emit(*this, Layout);
1040 // Pad to a multiple of the pointer size.
1042 offsetToAlignment(LOHRawSize, is64Bit() ? Align(8) : Align(4)));
1043 assert(W.OS.tell() - Start == LOHSize);
1044 }
1045
1046 // Write the symbol table data, if used.
1047 if (NumSymbols) {
1048 // Write the indirect symbol entries.
1050 it = Asm.indirect_symbol_begin(),
1051 ie = Asm.indirect_symbol_end(); it != ie; ++it) {
1052 // Indirect symbols in the non-lazy symbol pointer section have some
1053 // special handling.
1054 const MCSectionMachO &Section =
1055 static_cast<const MCSectionMachO &>(*it->Section);
1056 if (Section.getType() == MachO::S_NON_LAZY_SYMBOL_POINTERS) {
1057 // If this symbol is defined and internal, mark it as such.
1058 if (it->Symbol->isDefined() && !it->Symbol->isExternal()) {
1060 if (it->Symbol->isAbsolute())
1062 W.write<uint32_t>(Flags);
1063 continue;
1064 }
1065 }
1066
1067 W.write<uint32_t>(it->Symbol->getIndex());
1068 }
1069
1070 // FIXME: Check that offsets match computed ones.
1071
1072 // Write the symbol table entries.
1073 for (auto *SymbolData :
1074 {&LocalSymbolData, &ExternalSymbolData, &UndefinedSymbolData})
1075 for (MachSymbolData &Entry : *SymbolData)
1076 writeNlist(Entry, Layout);
1077
1078 // Write the string table.
1079 StringTable.write(W.OS);
1080 }
1081
1082 return W.OS.tell() - StartOffset;
1083}
1084
1085std::unique_ptr<MCObjectWriter>
1086llvm::createMachObjectWriter(std::unique_ptr<MCMachObjectTargetWriter> MOTW,
1087 raw_pwrite_stream &OS, bool IsLittleEndian) {
1088 return std::make_unique<MachObjectWriter>(std::move(MOTW), OS,
1089 IsLittleEndian);
1090}
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
static GCRegistry::Add< ErlangGC > A("erlang", "erlang-compatible garbage collector")
#define LLVM_DEBUG(X)
Definition: Debug.h:101
This file defines the DenseMap class.
std::string Name
uint64_t Size
bool End
Definition: ELF_riscv.cpp:480
Symbol * Sym
Definition: ELF_riscv.cpp:479
static LVOptions Options
Definition: LVOptions.cpp:25
static unsigned ComputeLinkerOptionsLoadCommandSize(const std::vector< std::string > &Options, bool is64Bit)
static bool isFixupTargetValid(const MCValue &Target)
static MachO::LoadCommandType getLCFromMCVM(MCVersionMinType Type)
PowerPC TLS Dynamic Call Fixup
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
raw_pwrite_stream & OS
static bool is64Bit(const char *name)
Value * RHS
ValueT lookup(const_arg_type_t< KeyT > Val) const
lookup - Return the entry for the specified key, or a default constructed value if no such entry exis...
Definition: DenseMap.h:202
Encapsulates the layout of an assembly file at a particular point in time.
Definition: MCAsmLayout.h:28
uint64_t getSectionAddressSize(const MCSection *Sec) const
Get the address space size of the given section, as it effects layout.
Definition: MCFragment.cpp:198
llvm::SmallVectorImpl< MCSection * > & getSectionOrder()
Definition: MCAsmLayout.h:69
uint64_t getSectionFileSize(const MCSection *Sec) const
Get the data size of the given section, as emitted to the object file.
Definition: MCFragment.cpp:204
bool getSymbolOffset(const MCSymbol &S, uint64_t &Val) const
Get the offset of the given symbol, as computed in the current layout.
Definition: MCFragment.cpp:152
uint64_t getFragmentOffset(const MCFragment *F) const
Get the offset of the given fragment inside its containing section.
Definition: MCFragment.cpp:96
MCAssembler & getAssembler() const
Get the assembler object this is a layout for.
Definition: MCAsmLayout.h:50
std::vector< IndirectSymbolData >::const_iterator const_indirect_symbol_iterator
Definition: MCAssembler.h:91
std::vector< DataRegionData >::const_iterator const_data_region_iterator
Definition: MCAssembler.h:95
const VersionInfoType & getVersionInfo() const
MachO deployment target version information.
Definition: MCAssembler.h:285
std::vector< IndirectSymbolData >::iterator indirect_symbol_iterator
Definition: MCAssembler.h:92
const VersionInfoType & getDarwinTargetVariantVersionInfo() const
Definition: MCAssembler.h:307
{ bool EmitBuildVersion VersionInfoType
MachO specific deployment target version info.
Definition: MCAssembler.h:102
Fragment for data and encoded instructions.
Definition: MCFragment.h:242
SmallVectorImpl< char > & getContents()
Definition: MCFragment.h:197
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:35
bool evaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout, const MCFixup *Fixup) const
Try to evaluate the expression to a relocatable value, i.e.
Definition: MCExpr.cpp:810
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:71
const MCSymbol * getAtom() const
Definition: MCFragment.h:99
MCSection * getParent() const
Definition: MCFragment.h:96
std::vector< const MCSymbol * > & getAddrsigSyms()
virtual void reset()
lifetime management
virtual bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, const MCSymbol &A, const MCSymbol &B, bool InSet) const
This represents a section on a Mach-O system (used by Mac OS X).
Instances of this class represent a uniqued identifier for a section in the current translation unit.
Definition: MCSection.h:39
unsigned getLayoutOrder() const
Definition: MCSection.h:152
MCSection::FragmentListType & getFragmentList()
Definition: MCSection.h:172
Align getAlign() const
Definition: MCSection.h:140
virtual bool isVirtualSection() const =0
Check whether this section is "virtual", that is has no actual object file contents.
const MCSymbol & getSymbol() const
Definition: MCExpr.h:408
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:40
const MCExpr * getVariableValue(bool SetUsed=true) const
getVariableValue - Get the value for variable symbols.
Definition: MCSymbol.h:305
bool isInSection() const
isInSection - Check if this symbol is defined in some section (i.e., it is defined but not absolute).
Definition: MCSymbol.h:254
StringRef getName() const
getName - Get the symbol name.
Definition: MCSymbol.h:205
bool isVariable() const
isVariable - Check if this is a variable symbol.
Definition: MCSymbol.h:300
bool isUndefined(bool SetUsed=true) const
isUndefined - Check if this symbol undefined (i.e., implicitly defined).
Definition: MCSymbol.h:259
uint32_t getIndex() const
Get the (implementation defined) index.
Definition: MCSymbol.h:316
MCSection & getSection() const
Get the section associated with a defined, non-absolute symbol.
Definition: MCSymbol.h:269
bool isTemporary() const
isTemporary - Check if this is an assembler temporary symbol.
Definition: MCSymbol.h:222
MCFragment * getFragment(bool SetUsed=true) const
Definition: MCSymbol.h:397
This represents an "assembler immediate".
Definition: MCValue.h:36
bool doesSymbolRequireExternRelocation(const MCSymbol &S)
uint64_t getSymbolAddress(const MCSymbol &S, const MCAsmLayout &Layout) const
void computeSymbolTable(MCAssembler &Asm, std::vector< MachSymbolData > &LocalSymbolData, std::vector< MachSymbolData > &ExternalSymbolData, std::vector< MachSymbolData > &UndefinedSymbolData)
Compute the symbol table data.
uint64_t getSectionAddress(const MCSection *Sec) const
void addRelocation(const MCSymbol *RelSymbol, const MCSection *Sec, MachO::any_relocation_info &MRE)
uint64_t writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override
Write the object file and returns the number of bytes written.
void populateAddrSigSection(MCAssembler &Asm)
bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind)
support::endian::Writer W
void executePostLayoutBinding(MCAssembler &Asm, const MCAsmLayout &Layout) override
Perform any late binding of symbols (for example, to assign symbol indices for use when generating re...
void writeLinkerOptionsLoadCommand(const std::vector< std::string > &Options)
void writeDysymtabLoadCommand(uint32_t FirstLocalSymbol, uint32_t NumLocalSymbols, uint32_t FirstExternalSymbol, uint32_t NumExternalSymbols, uint32_t FirstUndefinedSymbol, uint32_t NumUndefinedSymbols, uint32_t IndirectSymbolOffset, uint32_t NumIndirectSymbols)
void writeNlist(MachSymbolData &MSD, const MCAsmLayout &Layout)
const MCSymbol & findAliasedSymbol(const MCSymbol &Sym) const
bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, const MCSymbol &A, const MCSymbol &B, bool InSet) const override
void writeSection(const MCAsmLayout &Layout, const MCSection &Sec, uint64_t VMAddr, uint64_t FileOffset, unsigned Flags, uint64_t RelocationsStart, unsigned NumRelocations)
void writeSegmentLoadCommand(StringRef Name, unsigned NumSections, uint64_t VMAddr, uint64_t VMSize, uint64_t SectionDataStartOffset, uint64_t SectionDataSize, uint32_t MaxProt, uint32_t InitProt)
Write a segment load command.
void writeLinkeditLoadCommand(uint32_t Type, uint32_t DataOffset, uint32_t DataSize)
void writeHeader(MachO::HeaderFileType Type, unsigned NumLoadCommands, unsigned LoadCommandsSize, bool SubsectionsViaSymbols)
uint64_t getFragmentAddress(const MCFragment *Fragment, const MCAsmLayout &Layout) const
void reset() override
lifetime management
void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout, const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target, uint64_t &FixedValue) override
Record a relocation entry.
void computeSectionAddresses(const MCAssembler &Asm, const MCAsmLayout &Layout)
void writeSymtabLoadCommand(uint32_t SymbolOffset, uint32_t NumSymbols, uint32_t StringTableOffset, uint32_t StringTableSize)
void bindIndirectSymbols(MCAssembler &Asm)
uint64_t getPaddingSize(const MCSection *SD, const MCAsmLayout &Layout) const
static SectionKind getMetadata()
Definition: SectionKind.h:188
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
size_t getOffset(CachedHashStringRef S) const
Get the offest of a string in the string table.
void write(raw_ostream &OS) const
size_t add(CachedHashStringRef S)
Add a string to the builder.
void finalize()
Analyze the strings and build the final table.
Target - Wrapper for Target specific information.
const char * getName() const
getName - Get the target name.
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
LLVM Value Representation.
Definition: Value.h:74
StringRef getName() const
Return a constant reference to the value's name.
Definition: Value.cpp:309
Represents a version number in the form major[.minor[.subminor[.build]]].
Definition: VersionTuple.h:29
raw_ostream & write_zeros(unsigned NumZeros)
write_zeros - Insert 'NumZeros' nulls.
uint64_t tell() const
tell - Return the current offset with the file.
Definition: raw_ostream.h:150
An abstract base class for streams implementations that also support a pwrite operation.
Definition: raw_ostream.h:444
A raw_ostream that writes to an SmallVector or SmallString.
Definition: raw_ostream.h:690
This provides a very simple, boring adaptor for a begin and end iterator into a range type.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
@ C
The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
@ N_PEXT
Definition: MachO.h:308
HeaderFileType
Definition: MachO.h:40
@ MH_OBJECT
Definition: MachO.h:43
@ S_THREAD_LOCAL_VARIABLE_POINTERS
S_THREAD_LOCAL_VARIABLE_POINTERS - Section with pointers to thread local structures.
Definition: MachO.h:175
@ S_LAZY_SYMBOL_POINTERS
S_LAZY_SYMBOL_POINTERS - Section with lazy symbol pointers.
Definition: MachO.h:141
@ S_NON_LAZY_SYMBOL_POINTERS
S_NON_LAZY_SYMBOL_POINTERS - Section with non-lazy symbol pointers.
Definition: MachO.h:139
@ S_SYMBOL_STUBS
S_SYMBOL_STUBS - Section with symbol stubs, byte size of stub in the Reserved2 field.
Definition: MachO.h:144
@ MH_SUBSECTIONS_VIA_SYMBOLS
Definition: MachO.h:73
@ S_ATTR_SOME_INSTRUCTIONS
S_ATTR_SOME_INSTRUCTIONS - Section contains some machine instructions.
Definition: MachO.h:213
@ INDIRECT_SYMBOL_ABS
Definition: MachO.h:222
@ INDIRECT_SYMBOL_LOCAL
Definition: MachO.h:221
@ N_SECT
Definition: MachO.h:318
@ N_INDR
Definition: MachO.h:320
@ N_UNDF
Definition: MachO.h:316
@ GENERIC_RELOC_VANILLA
Definition: MachO.h:410
LoadCommandType
Definition: MachO.h:98
@ VM_PROT_EXECUTE
Definition: MachO.h:497
@ VM_PROT_READ
Definition: MachO.h:497
@ VM_PROT_WRITE
Definition: MachO.h:497
@ MH_MAGIC
Definition: MachO.h:30
@ MH_MAGIC_64
Definition: MachO.h:32
void write(void *memory, value_type value, endianness endian)
Write a value to memory with a particular endianness.
Definition: Endian.h:91
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
std::unique_ptr< MCObjectWriter > createMachObjectWriter(std::unique_ptr< MCMachObjectTargetWriter > MOTW, raw_pwrite_stream &OS, bool IsLittleEndian)
Construct a new Mach-O writer instance.
iterator_range< T > make_range(T x, T y)
Convenience function for iterating over sub-ranges.
auto reverse(ContainerTy &&C)
Definition: STLExtras.h:428
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:1656
MCVersionMinType
Definition: MCDirectives.h:69
@ MCVM_WatchOSVersionMin
.watchos_version_min
Definition: MCDirectives.h:73
@ MCVM_OSXVersionMin
.macosx_version_min
Definition: MCDirectives.h:71
@ MCVM_TvOSVersionMin
.tvos_version_min
Definition: MCDirectives.h:72
@ MCVM_IOSVersionMin
.ios_version_min
Definition: MCDirectives.h:70
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:163
void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:156
MCFixupKind
Extensible enumeration to represent the type of a fixup.
Definition: MCFixup.h:21
uint64_t offsetToAlignment(uint64_t Value, Align Alignment)
Returns the offset to the next integer (mod 2**64) that is greater than or equal to Value and is a mu...
Definition: Alignment.h:197
@ Ref
The access may reference the value stored in memory.
uint64_t alignTo(uint64_t Size, Align A)
Returns a multiple of A needed to store Size bytes.
Definition: Alignment.h:155
unsigned Log2(Align A)
Returns the log2 of the alignment.
Definition: Alignment.h:208
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
const MCSymbolRefExpr * From
Definition: MCAssembler.h:471
const MCSymbolRefExpr * To
Definition: MCAssembler.h:472
Target independent information on a fixup kind.
@ FKF_IsPCRel
Is this fixup kind PCrelative? This is used by the assembler backend to evaluate fixup values in a ta...
unsigned Flags
Flags describing additional information on this fixup kind.
An iterator type that allows iterating over the pointees via some other iterator.
Definition: iterator.h:324
void write(ArrayRef< value_type > Val)
Definition: EndianStream.h:71