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Daniel Dunbar79e0e5a2010-03-19 10:43:15 +00001//===- lib/MC/MachObjectWriter.cpp - Mach-O File Writer -------------------===//
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
Daniel Dunbar8888a962010-12-16 16:09:19 +000010#include "llvm/MC/MCMachObjectWriter.h"
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +000011#include "llvm/ADT/StringMap.h"
12#include "llvm/ADT/Twine.h"
Evan Cheng5928e692011-07-25 23:24:55 +000013#include "llvm/MC/MCAsmBackend.h"
Daniel Dunbar7c969552010-03-24 03:43:40 +000014#include "llvm/MC/MCAsmLayout.h"
Chandler Carruthed0881b2012-12-03 16:50:05 +000015#include "llvm/MC/MCAssembler.h"
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +000016#include "llvm/MC/MCExpr.h"
Craig Topper6e80c282012-03-26 06:58:25 +000017#include "llvm/MC/MCFixupKindInfo.h"
Chandler Carruthed0881b2012-12-03 16:50:05 +000018#include "llvm/MC/MCMachOSymbolFlags.h"
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +000019#include "llvm/MC/MCObjectWriter.h"
20#include "llvm/MC/MCSectionMachO.h"
21#include "llvm/MC/MCSymbol.h"
22#include "llvm/MC/MCValue.h"
Jim Grosbach4b63d2a2012-05-18 19:12:01 +000023#include "llvm/Support/Debug.h"
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +000024#include "llvm/Support/ErrorHandling.h"
Charles Davis8bdfafd2013-09-01 04:28:48 +000025#include "llvm/Support/MachO.h"
Benjamin Kramer799003b2015-03-23 19:32:43 +000026#include "llvm/Support/raw_ostream.h"
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +000027#include <vector>
28using namespace llvm;
29
Chandler Carruthe96dd892014-04-21 22:55:11 +000030#define DEBUG_TYPE "mc"
31
Pedro Artigasb95c53e2012-12-14 18:52:11 +000032void MachObjectWriter::reset() {
33 Relocations.clear();
34 IndirectSymBase.clear();
35 StringTable.clear();
36 LocalSymbolData.clear();
37 ExternalSymbolData.clear();
38 UndefinedSymbolData.clear();
39 MCObjectWriter::reset();
40}
41
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +000042bool MachObjectWriter::doesSymbolRequireExternRelocation(const MCSymbol &S) {
Daniel Dunbar7de31062010-05-10 23:15:13 +000043 // Undefined symbols are always extern.
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +000044 if (S.isUndefined())
Daniel Dunbar7de31062010-05-10 23:15:13 +000045 return true;
46
47 // References to weak definitions require external relocation entries; the
48 // definition may not always be the one in the same object file.
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +000049 if (S.getData().getFlags() & SF_WeakDefinition)
Daniel Dunbar7de31062010-05-10 23:15:13 +000050 return true;
51
52 // Otherwise, we can use an internal relocation.
53 return false;
54}
55
Jim Grosbach28fcafb2011-06-24 23:44:37 +000056bool MachObjectWriter::
57MachSymbolData::operator<(const MachSymbolData &RHS) const {
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +000058 return Symbol->getName() < RHS.Symbol->getName();
Jim Grosbach28fcafb2011-06-24 23:44:37 +000059}
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +000060
Jim Grosbach28fcafb2011-06-24 23:44:37 +000061bool MachObjectWriter::isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
62 const MCFixupKindInfo &FKI = Asm.getBackend().getFixupKindInfo(
63 (MCFixupKind) Kind);
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +000064
Jim Grosbach28fcafb2011-06-24 23:44:37 +000065 return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel;
66}
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +000067
Jim Grosbach28fcafb2011-06-24 23:44:37 +000068uint64_t MachObjectWriter::getFragmentAddress(const MCFragment *Fragment,
69 const MCAsmLayout &Layout) const {
Rafael Espindola079027e2015-05-26 00:52:18 +000070 return getSectionAddress(Fragment->getParent()) +
Rafael Espindola7549f872015-05-26 00:36:57 +000071 Layout.getFragmentOffset(Fragment);
Jim Grosbach28fcafb2011-06-24 23:44:37 +000072}
Bill Wendlingeb872e02011-06-22 21:07:27 +000073
Duncan P. N. Exon Smith99d8a8e2015-05-20 00:02:39 +000074uint64_t MachObjectWriter::getSymbolAddress(const MCSymbol &S,
Bill Wendlingeb872e02011-06-22 21:07:27 +000075 const MCAsmLayout &Layout) const {
Bill Wendlingeb872e02011-06-22 21:07:27 +000076 // If this is a variable, then recursively evaluate now.
77 if (S.isVariable()) {
Jim Grosbachd96ef192012-09-13 23:11:25 +000078 if (const MCConstantExpr *C =
79 dyn_cast<const MCConstantExpr>(S.getVariableValue()))
80 return C->getValue();
81
82
Bill Wendlingeb872e02011-06-22 21:07:27 +000083 MCValue Target;
Joerg Sonnenberger752b91b2014-08-10 11:35:12 +000084 if (!S.getVariableValue()->EvaluateAsRelocatable(Target, &Layout, nullptr))
Bill Wendlingeb872e02011-06-22 21:07:27 +000085 report_fatal_error("unable to evaluate offset for variable '" +
86 S.getName() + "'");
87
88 // Verify that any used symbols are defined.
89 if (Target.getSymA() && Target.getSymA()->getSymbol().isUndefined())
90 report_fatal_error("unable to evaluate offset to undefined symbol '" +
91 Target.getSymA()->getSymbol().getName() + "'");
92 if (Target.getSymB() && Target.getSymB()->getSymbol().isUndefined())
93 report_fatal_error("unable to evaluate offset to undefined symbol '" +
94 Target.getSymB()->getSymbol().getName() + "'");
95
96 uint64_t Address = Target.getConstant();
97 if (Target.getSymA())
Duncan P. N. Exon Smith99d8a8e2015-05-20 00:02:39 +000098 Address += getSymbolAddress(Target.getSymA()->getSymbol(), Layout);
Bill Wendlingeb872e02011-06-22 21:07:27 +000099 if (Target.getSymB())
Duncan P. N. Exon Smith99d8a8e2015-05-20 00:02:39 +0000100 Address += getSymbolAddress(Target.getSymB()->getSymbol(), Layout);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000101 return Address;
102 }
103
Rafael Espindola079027e2015-05-26 00:52:18 +0000104 return getSectionAddress(S.getData().getFragment()->getParent()) +
Duncan P. N. Exon Smith2a404832015-05-19 23:53:20 +0000105 Layout.getSymbolOffset(S);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000106}
107
Rafael Espindola61e724a2015-05-26 01:15:30 +0000108uint64_t MachObjectWriter::getPaddingSize(const MCSection *Sec,
Bill Wendlingeb872e02011-06-22 21:07:27 +0000109 const MCAsmLayout &Layout) const {
Rafael Espindola61e724a2015-05-26 01:15:30 +0000110 uint64_t EndAddr = getSectionAddress(Sec) +
111 Layout.getSectionAddressSize(&Sec->getSectionData());
112 unsigned Next = Sec->getLayoutOrder() + 1;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000113 if (Next >= Layout.getSectionOrder().size())
114 return 0;
115
116 const MCSectionData &NextSD = *Layout.getSectionOrder()[Next];
117 if (NextSD.getSection().isVirtualSection())
118 return 0;
Rafael Espindola967d6a62015-05-21 21:02:35 +0000119 return OffsetToAlignment(EndAddr, NextSD.getSection().getAlignment());
Bill Wendlingeb872e02011-06-22 21:07:27 +0000120}
121
122void MachObjectWriter::WriteHeader(unsigned NumLoadCommands,
123 unsigned LoadCommandsSize,
124 bool SubsectionsViaSymbols) {
125 uint32_t Flags = 0;
126
127 if (SubsectionsViaSymbols)
Charles Davis8bdfafd2013-09-01 04:28:48 +0000128 Flags |= MachO::MH_SUBSECTIONS_VIA_SYMBOLS;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000129
130 // struct mach_header (28 bytes) or
131 // struct mach_header_64 (32 bytes)
132
133 uint64_t Start = OS.tell();
134 (void) Start;
135
Charles Davis8bdfafd2013-09-01 04:28:48 +0000136 Write32(is64Bit() ? MachO::MH_MAGIC_64 : MachO::MH_MAGIC);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000137
138 Write32(TargetObjectWriter->getCPUType());
139 Write32(TargetObjectWriter->getCPUSubtype());
140
Charles Davis8bdfafd2013-09-01 04:28:48 +0000141 Write32(MachO::MH_OBJECT);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000142 Write32(NumLoadCommands);
143 Write32(LoadCommandsSize);
144 Write32(Flags);
145 if (is64Bit())
146 Write32(0); // reserved
147
148 assert(OS.tell() - Start ==
Charles Davis8bdfafd2013-09-01 04:28:48 +0000149 (is64Bit()?sizeof(MachO::mach_header_64): sizeof(MachO::mach_header)));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000150}
151
152/// WriteSegmentLoadCommand - Write a segment load command.
153///
Dmitri Gribenko5485acd2012-09-14 14:57:36 +0000154/// \param NumSections The number of sections in this segment.
155/// \param SectionDataSize The total size of the sections.
Bill Wendlingeb872e02011-06-22 21:07:27 +0000156void MachObjectWriter::WriteSegmentLoadCommand(unsigned NumSections,
157 uint64_t VMSize,
158 uint64_t SectionDataStartOffset,
159 uint64_t SectionDataSize) {
160 // struct segment_command (56 bytes) or
161 // struct segment_command_64 (72 bytes)
162
163 uint64_t Start = OS.tell();
164 (void) Start;
165
166 unsigned SegmentLoadCommandSize =
Charles Davis8bdfafd2013-09-01 04:28:48 +0000167 is64Bit() ? sizeof(MachO::segment_command_64):
168 sizeof(MachO::segment_command);
169 Write32(is64Bit() ? MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000170 Write32(SegmentLoadCommandSize +
Charles Davis8bdfafd2013-09-01 04:28:48 +0000171 NumSections * (is64Bit() ? sizeof(MachO::section_64) :
172 sizeof(MachO::section)));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000173
174 WriteBytes("", 16);
175 if (is64Bit()) {
176 Write64(0); // vmaddr
177 Write64(VMSize); // vmsize
178 Write64(SectionDataStartOffset); // file offset
179 Write64(SectionDataSize); // file size
180 } else {
181 Write32(0); // vmaddr
182 Write32(VMSize); // vmsize
183 Write32(SectionDataStartOffset); // file offset
184 Write32(SectionDataSize); // file size
185 }
Nick Kledzikfe6813f2013-09-04 23:53:44 +0000186 // maxprot
187 Write32(MachO::VM_PROT_READ | MachO::VM_PROT_WRITE | MachO::VM_PROT_EXECUTE);
188 // initprot
189 Write32(MachO::VM_PROT_READ | MachO::VM_PROT_WRITE | MachO::VM_PROT_EXECUTE);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000190 Write32(NumSections);
191 Write32(0); // flags
192
193 assert(OS.tell() - Start == SegmentLoadCommandSize);
194}
195
196void MachObjectWriter::WriteSection(const MCAssembler &Asm,
197 const MCAsmLayout &Layout,
Rafael Espindola61e724a2015-05-26 01:15:30 +0000198 const MCSection &Sec, uint64_t FileOffset,
Bill Wendlingeb872e02011-06-22 21:07:27 +0000199 uint64_t RelocationsStart,
200 unsigned NumRelocations) {
Rafael Espindola61e724a2015-05-26 01:15:30 +0000201 const MCSectionData &SD = Sec.getSectionData();
Bill Wendlingeb872e02011-06-22 21:07:27 +0000202 uint64_t SectionSize = Layout.getSectionAddressSize(&SD);
Rafael Espindola61e724a2015-05-26 01:15:30 +0000203 const MCSectionMachO &Section = cast<MCSectionMachO>(Sec);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000204
205 // The offset is unused for virtual sections.
Rafael Espindola967d6a62015-05-21 21:02:35 +0000206 if (Section.isVirtualSection()) {
Bill Wendlingeb872e02011-06-22 21:07:27 +0000207 assert(Layout.getSectionFileSize(&SD) == 0 && "Invalid file size!");
208 FileOffset = 0;
209 }
210
211 // struct section (68 bytes) or
212 // struct section_64 (80 bytes)
213
214 uint64_t Start = OS.tell();
215 (void) Start;
216
Bill Wendlingeb872e02011-06-22 21:07:27 +0000217 WriteBytes(Section.getSectionName(), 16);
218 WriteBytes(Section.getSegmentName(), 16);
219 if (is64Bit()) {
Rafael Espindola079027e2015-05-26 00:52:18 +0000220 Write64(getSectionAddress(&SD.getSection())); // address
Bill Wendlingeb872e02011-06-22 21:07:27 +0000221 Write64(SectionSize); // size
222 } else {
Rafael Espindola079027e2015-05-26 00:52:18 +0000223 Write32(getSectionAddress(&SD.getSection())); // address
Bill Wendlingeb872e02011-06-22 21:07:27 +0000224 Write32(SectionSize); // size
225 }
226 Write32(FileOffset);
227
228 unsigned Flags = Section.getTypeAndAttributes();
Rafael Espindolacd625182015-05-25 18:34:26 +0000229 if (Section.hasInstructions())
David Majnemer7b583052014-03-07 07:36:05 +0000230 Flags |= MachO::S_ATTR_SOME_INSTRUCTIONS;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000231
Rafael Espindola967d6a62015-05-21 21:02:35 +0000232 assert(isPowerOf2_32(Section.getAlignment()) && "Invalid alignment!");
233 Write32(Log2_32(Section.getAlignment()));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000234 Write32(NumRelocations ? RelocationsStart : 0);
235 Write32(NumRelocations);
236 Write32(Flags);
Rafael Espindola61e724a2015-05-26 01:15:30 +0000237 Write32(IndirectSymBase.lookup(&SD.getSection())); // reserved1
Bill Wendlingeb872e02011-06-22 21:07:27 +0000238 Write32(Section.getStubSize()); // reserved2
239 if (is64Bit())
240 Write32(0); // reserved3
241
Charles Davis8bdfafd2013-09-01 04:28:48 +0000242 assert(OS.tell() - Start == (is64Bit() ? sizeof(MachO::section_64) :
243 sizeof(MachO::section)));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000244}
245
246void MachObjectWriter::WriteSymtabLoadCommand(uint32_t SymbolOffset,
247 uint32_t NumSymbols,
248 uint32_t StringTableOffset,
249 uint32_t StringTableSize) {
250 // struct symtab_command (24 bytes)
251
252 uint64_t Start = OS.tell();
253 (void) Start;
254
Charles Davis8bdfafd2013-09-01 04:28:48 +0000255 Write32(MachO::LC_SYMTAB);
256 Write32(sizeof(MachO::symtab_command));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000257 Write32(SymbolOffset);
258 Write32(NumSymbols);
259 Write32(StringTableOffset);
260 Write32(StringTableSize);
261
Charles Davis8bdfafd2013-09-01 04:28:48 +0000262 assert(OS.tell() - Start == sizeof(MachO::symtab_command));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000263}
264
265void MachObjectWriter::WriteDysymtabLoadCommand(uint32_t FirstLocalSymbol,
266 uint32_t NumLocalSymbols,
267 uint32_t FirstExternalSymbol,
268 uint32_t NumExternalSymbols,
269 uint32_t FirstUndefinedSymbol,
270 uint32_t NumUndefinedSymbols,
271 uint32_t IndirectSymbolOffset,
272 uint32_t NumIndirectSymbols) {
273 // struct dysymtab_command (80 bytes)
274
275 uint64_t Start = OS.tell();
276 (void) Start;
277
Charles Davis8bdfafd2013-09-01 04:28:48 +0000278 Write32(MachO::LC_DYSYMTAB);
279 Write32(sizeof(MachO::dysymtab_command));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000280 Write32(FirstLocalSymbol);
281 Write32(NumLocalSymbols);
282 Write32(FirstExternalSymbol);
283 Write32(NumExternalSymbols);
284 Write32(FirstUndefinedSymbol);
285 Write32(NumUndefinedSymbols);
286 Write32(0); // tocoff
287 Write32(0); // ntoc
288 Write32(0); // modtaboff
289 Write32(0); // nmodtab
290 Write32(0); // extrefsymoff
291 Write32(0); // nextrefsyms
292 Write32(IndirectSymbolOffset);
293 Write32(NumIndirectSymbols);
294 Write32(0); // extreloff
295 Write32(0); // nextrel
296 Write32(0); // locreloff
297 Write32(0); // nlocrel
298
Charles Davis8bdfafd2013-09-01 04:28:48 +0000299 assert(OS.tell() - Start == sizeof(MachO::dysymtab_command));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000300}
301
Tim Northovereaef0742014-05-30 13:22:59 +0000302MachObjectWriter::MachSymbolData *
303MachObjectWriter::findSymbolData(const MCSymbol &Sym) {
304 for (auto &Entry : LocalSymbolData)
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +0000305 if (Entry.Symbol == &Sym)
Tim Northovereaef0742014-05-30 13:22:59 +0000306 return &Entry;
307
308 for (auto &Entry : ExternalSymbolData)
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +0000309 if (Entry.Symbol == &Sym)
Tim Northovereaef0742014-05-30 13:22:59 +0000310 return &Entry;
311
312 for (auto &Entry : UndefinedSymbolData)
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +0000313 if (Entry.Symbol == &Sym)
Tim Northovereaef0742014-05-30 13:22:59 +0000314 return &Entry;
315
316 return nullptr;
317}
318
Rafael Espindola7f4e07b2015-04-17 12:28:43 +0000319const MCSymbol &MachObjectWriter::findAliasedSymbol(const MCSymbol &Sym) const {
320 const MCSymbol *S = &Sym;
321 while (S->isVariable()) {
322 const MCExpr *Value = S->getVariableValue();
323 const auto *Ref = dyn_cast<MCSymbolRefExpr>(Value);
324 if (!Ref)
325 return *S;
326 S = &Ref->getSymbol();
327 }
328 return *S;
329}
330
Bill Wendling21162212011-06-23 00:09:43 +0000331void MachObjectWriter::WriteNlist(MachSymbolData &MSD,
332 const MCAsmLayout &Layout) {
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +0000333 const MCSymbol *Symbol = MSD.Symbol;
334 MCSymbolData &Data = Symbol->getData();
Rafael Espindola7f4e07b2015-04-17 12:28:43 +0000335 const MCSymbol *AliasedSymbol = &findAliasedSymbol(*Symbol);
Tim Northovereaef0742014-05-30 13:22:59 +0000336 uint8_t SectionIndex = MSD.SectionIndex;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000337 uint8_t Type = 0;
338 uint16_t Flags = Data.getFlags();
Jim Grosbacha3171602011-08-09 22:12:37 +0000339 uint64_t Address = 0;
Tim Northovereaef0742014-05-30 13:22:59 +0000340 bool IsAlias = Symbol != AliasedSymbol;
341
Duncan P. N. Exon Smith24f47752015-05-21 00:39:24 +0000342 const MCSymbol &OrigSymbol = *Symbol;
Tim Northovereaef0742014-05-30 13:22:59 +0000343 MachSymbolData *AliaseeInfo;
344 if (IsAlias) {
345 AliaseeInfo = findSymbolData(*AliasedSymbol);
346 if (AliaseeInfo)
347 SectionIndex = AliaseeInfo->SectionIndex;
348 Symbol = AliasedSymbol;
Duncan P. N. Exon Smith24f47752015-05-21 00:39:24 +0000349 // FIXME: Should this update Data as well? Do we need OrigSymbol at all?
Tim Northovereaef0742014-05-30 13:22:59 +0000350 }
Bill Wendlingeb872e02011-06-22 21:07:27 +0000351
352 // Set the N_TYPE bits. See <mach-o/nlist.h>.
353 //
354 // FIXME: Are the prebound or indirect fields possible here?
Tim Northovereaef0742014-05-30 13:22:59 +0000355 if (IsAlias && Symbol->isUndefined())
356 Type = MachO::N_INDR;
357 else if (Symbol->isUndefined())
Charles Davis8bdfafd2013-09-01 04:28:48 +0000358 Type = MachO::N_UNDF;
Tim Northovereaef0742014-05-30 13:22:59 +0000359 else if (Symbol->isAbsolute())
Charles Davis8bdfafd2013-09-01 04:28:48 +0000360 Type = MachO::N_ABS;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000361 else
Charles Davis8bdfafd2013-09-01 04:28:48 +0000362 Type = MachO::N_SECT;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000363
364 // FIXME: Set STAB bits.
365
366 if (Data.isPrivateExtern())
Charles Davis8bdfafd2013-09-01 04:28:48 +0000367 Type |= MachO::N_PEXT;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000368
369 // Set external bit.
Tim Northovereaef0742014-05-30 13:22:59 +0000370 if (Data.isExternal() || (!IsAlias && Symbol->isUndefined()))
Charles Davis8bdfafd2013-09-01 04:28:48 +0000371 Type |= MachO::N_EXT;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000372
373 // Compute the symbol address.
Tim Northovereaef0742014-05-30 13:22:59 +0000374 if (IsAlias && Symbol->isUndefined())
375 Address = AliaseeInfo->StringIndex;
376 else if (Symbol->isDefined())
Duncan P. N. Exon Smith24f47752015-05-21 00:39:24 +0000377 Address = getSymbolAddress(OrigSymbol, Layout);
Tim Northovereaef0742014-05-30 13:22:59 +0000378 else if (Data.isCommon()) {
Bill Wendlingeb872e02011-06-22 21:07:27 +0000379 // Common symbols are encoded with the size in the address
380 // field, and their alignment in the flags.
381 Address = Data.getCommonSize();
382
383 // Common alignment is packed into the 'desc' bits.
384 if (unsigned Align = Data.getCommonAlignment()) {
385 unsigned Log2Size = Log2_32(Align);
386 assert((1U << Log2Size) == Align && "Invalid 'common' alignment!");
387 if (Log2Size > 15)
388 report_fatal_error("invalid 'common' alignment '" +
Tim Northovereaef0742014-05-30 13:22:59 +0000389 Twine(Align) + "' for '" + Symbol->getName() + "'",
Jim Grosbachaff6a0c2013-09-24 23:56:31 +0000390 false);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000391 // FIXME: Keep this mask with the SymbolFlags enumeration.
392 Flags = (Flags & 0xF0FF) | (Log2Size << 8);
393 }
394 }
395
Tim Northovereaef0742014-05-30 13:22:59 +0000396 if (Layout.getAssembler().isThumbFunc(Symbol))
Rafael Espindolab60c8292014-04-29 12:46:50 +0000397 Flags |= SF_ThumbFunc;
398
Bill Wendlingeb872e02011-06-22 21:07:27 +0000399 // struct nlist (12 bytes)
400
401 Write32(MSD.StringIndex);
402 Write8(Type);
Tim Northovereaef0742014-05-30 13:22:59 +0000403 Write8(SectionIndex);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000404
405 // The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc'
406 // value.
407 Write16(Flags);
408 if (is64Bit())
409 Write64(Address);
410 else
411 Write32(Address);
412}
413
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000414void MachObjectWriter::WriteLinkeditLoadCommand(uint32_t Type,
415 uint32_t DataOffset,
416 uint32_t DataSize) {
417 uint64_t Start = OS.tell();
418 (void) Start;
419
420 Write32(Type);
Charles Davis8bdfafd2013-09-01 04:28:48 +0000421 Write32(sizeof(MachO::linkedit_data_command));
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000422 Write32(DataOffset);
423 Write32(DataSize);
424
Charles Davis8bdfafd2013-09-01 04:28:48 +0000425 assert(OS.tell() - Start == sizeof(MachO::linkedit_data_command));
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000426}
427
Daniel Dunbareec0f322013-01-18 01:26:07 +0000428static unsigned ComputeLinkerOptionsLoadCommandSize(
Daniel Dunbar34ea79f2013-01-22 03:42:49 +0000429 const std::vector<std::string> &Options, bool is64Bit)
Daniel Dunbareec0f322013-01-18 01:26:07 +0000430{
Kevin Enderbyd0b6b7f2014-12-18 00:53:40 +0000431 unsigned Size = sizeof(MachO::linker_option_command);
Daniel Dunbareec0f322013-01-18 01:26:07 +0000432 for (unsigned i = 0, e = Options.size(); i != e; ++i)
433 Size += Options[i].size() + 1;
Daniel Dunbar34ea79f2013-01-22 03:42:49 +0000434 return RoundUpToAlignment(Size, is64Bit ? 8 : 4);
Daniel Dunbareec0f322013-01-18 01:26:07 +0000435}
436
437void MachObjectWriter::WriteLinkerOptionsLoadCommand(
438 const std::vector<std::string> &Options)
439{
Daniel Dunbar34ea79f2013-01-22 03:42:49 +0000440 unsigned Size = ComputeLinkerOptionsLoadCommandSize(Options, is64Bit());
Daniel Dunbareec0f322013-01-18 01:26:07 +0000441 uint64_t Start = OS.tell();
442 (void) Start;
443
Kevin Enderbyd0b6b7f2014-12-18 00:53:40 +0000444 Write32(MachO::LC_LINKER_OPTION);
Daniel Dunbareec0f322013-01-18 01:26:07 +0000445 Write32(Size);
446 Write32(Options.size());
Kevin Enderbyd0b6b7f2014-12-18 00:53:40 +0000447 uint64_t BytesWritten = sizeof(MachO::linker_option_command);
Daniel Dunbareec0f322013-01-18 01:26:07 +0000448 for (unsigned i = 0, e = Options.size(); i != e; ++i) {
449 // Write each string, including the null byte.
450 const std::string &Option = Options[i];
451 WriteBytes(Option.c_str(), Option.size() + 1);
452 BytesWritten += Option.size() + 1;
453 }
454
Daniel Dunbar34ea79f2013-01-22 03:42:49 +0000455 // Pad to a multiple of the pointer size.
456 WriteBytes("", OffsetToAlignment(BytesWritten, is64Bit() ? 8 : 4));
Daniel Dunbareec0f322013-01-18 01:26:07 +0000457
458 assert(OS.tell() - Start == Size);
459}
460
Rafael Espindola26585542015-01-19 21:11:14 +0000461void MachObjectWriter::RecordRelocation(MCAssembler &Asm,
Bill Wendlingeb872e02011-06-22 21:07:27 +0000462 const MCAsmLayout &Layout,
463 const MCFragment *Fragment,
Rafael Espindola26585542015-01-19 21:11:14 +0000464 const MCFixup &Fixup, MCValue Target,
465 bool &IsPCRel, uint64_t &FixedValue) {
Jim Grosbach28fcafb2011-06-24 23:44:37 +0000466 TargetObjectWriter->RecordRelocation(this, Asm, Layout, Fragment, Fixup,
467 Target, FixedValue);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000468}
469
470void MachObjectWriter::BindIndirectSymbols(MCAssembler &Asm) {
471 // This is the point where 'as' creates actual symbols for indirect symbols
472 // (in the following two passes). It would be easier for us to do this sooner
473 // when we see the attribute, but that makes getting the order in the symbol
474 // table much more complicated than it is worth.
475 //
476 // FIXME: Revisit this when the dust settles.
477
Kevin Enderby3aeada22013-08-28 17:50:59 +0000478 // Report errors for use of .indirect_symbol not in a symbol pointer section
479 // or stub section.
480 for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
481 ie = Asm.indirect_symbol_end(); it != ie; ++it) {
482 const MCSectionMachO &Section =
483 cast<MCSectionMachO>(it->SectionData->getSection());
484
David Majnemer7b583052014-03-07 07:36:05 +0000485 if (Section.getType() != MachO::S_NON_LAZY_SYMBOL_POINTERS &&
486 Section.getType() != MachO::S_LAZY_SYMBOL_POINTERS &&
487 Section.getType() != MachO::S_SYMBOL_STUBS) {
Kevin Enderby3aeada22013-08-28 17:50:59 +0000488 MCSymbol &Symbol = *it->Symbol;
489 report_fatal_error("indirect symbol '" + Symbol.getName() +
490 "' not in a symbol pointer or stub section");
491 }
492 }
493
Alp Tokerf907b892013-12-05 05:44:44 +0000494 // Bind non-lazy symbol pointers first.
Bill Wendlingeb872e02011-06-22 21:07:27 +0000495 unsigned IndirectIndex = 0;
496 for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
497 ie = Asm.indirect_symbol_end(); it != ie; ++it, ++IndirectIndex) {
498 const MCSectionMachO &Section =
499 cast<MCSectionMachO>(it->SectionData->getSection());
500
David Majnemer7b583052014-03-07 07:36:05 +0000501 if (Section.getType() != MachO::S_NON_LAZY_SYMBOL_POINTERS)
Bill Wendlingeb872e02011-06-22 21:07:27 +0000502 continue;
503
504 // Initialize the section indirect symbol base, if necessary.
Rafael Espindola61e724a2015-05-26 01:15:30 +0000505 IndirectSymBase.insert(
506 std::make_pair(&it->SectionData->getSection(), IndirectIndex));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000507
508 Asm.getOrCreateSymbolData(*it->Symbol);
509 }
510
511 // Then lazy symbol pointers and symbol stubs.
512 IndirectIndex = 0;
513 for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
514 ie = Asm.indirect_symbol_end(); it != ie; ++it, ++IndirectIndex) {
515 const MCSectionMachO &Section =
516 cast<MCSectionMachO>(it->SectionData->getSection());
517
David Majnemer7b583052014-03-07 07:36:05 +0000518 if (Section.getType() != MachO::S_LAZY_SYMBOL_POINTERS &&
519 Section.getType() != MachO::S_SYMBOL_STUBS)
Bill Wendlingeb872e02011-06-22 21:07:27 +0000520 continue;
521
522 // Initialize the section indirect symbol base, if necessary.
Rafael Espindola61e724a2015-05-26 01:15:30 +0000523 IndirectSymBase.insert(
524 std::make_pair(&it->SectionData->getSection(), IndirectIndex));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000525
526 // Set the symbol type to undefined lazy, but only on construction.
527 //
528 // FIXME: Do not hardcode.
529 bool Created;
530 MCSymbolData &Entry = Asm.getOrCreateSymbolData(*it->Symbol, &Created);
531 if (Created)
532 Entry.setFlags(Entry.getFlags() | 0x0001);
533 }
534}
535
536/// ComputeSymbolTable - Compute the symbol table data
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000537void MachObjectWriter::ComputeSymbolTable(
538 MCAssembler &Asm, std::vector<MachSymbolData> &LocalSymbolData,
539 std::vector<MachSymbolData> &ExternalSymbolData,
540 std::vector<MachSymbolData> &UndefinedSymbolData) {
Bill Wendlingeb872e02011-06-22 21:07:27 +0000541 // Build section lookup table.
542 DenseMap<const MCSection*, uint8_t> SectionIndexMap;
543 unsigned Index = 1;
544 for (MCAssembler::iterator it = Asm.begin(),
545 ie = Asm.end(); it != ie; ++it, ++Index)
Rafael Espindolaa554c052015-05-25 23:14:17 +0000546 SectionIndexMap[&*it] = Index;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000547 assert(Index <= 256 && "Too many sections!");
548
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000549 // Build the string table.
Duncan P. N. Exon Smithf48de1c2015-05-16 00:35:24 +0000550 for (const MCSymbol &Symbol : Asm.symbols()) {
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000551 if (!Asm.isSymbolLinkerVisible(Symbol))
552 continue;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000553
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000554 StringTable.add(Symbol.getName());
555 }
556 StringTable.finalize(StringTableBuilder::MachO);
557
558 // Build the symbol arrays but only for non-local symbols.
Bill Wendlingeb872e02011-06-22 21:07:27 +0000559 //
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000560 // The particular order that we collect and then sort the symbols is chosen to
561 // match 'as'. Even though it doesn't matter for correctness, this is
562 // important for letting us diff .o files.
Duncan P. N. Exon Smithf48de1c2015-05-16 00:35:24 +0000563 for (const MCSymbol &Symbol : Asm.symbols()) {
564 MCSymbolData &SD = Symbol.getData();
Bill Wendlingeb872e02011-06-22 21:07:27 +0000565
566 // Ignore non-linker visible symbols.
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000567 if (!Asm.isSymbolLinkerVisible(Symbol))
Bill Wendlingeb872e02011-06-22 21:07:27 +0000568 continue;
569
David Blaikie583a31c2014-04-18 18:24:25 +0000570 if (!SD.isExternal() && !Symbol.isUndefined())
Bill Wendlingeb872e02011-06-22 21:07:27 +0000571 continue;
572
Bill Wendlingeb872e02011-06-22 21:07:27 +0000573 MachSymbolData MSD;
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +0000574 MSD.Symbol = &Symbol;
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000575 MSD.StringIndex = StringTable.getOffset(Symbol.getName());
Bill Wendlingeb872e02011-06-22 21:07:27 +0000576
577 if (Symbol.isUndefined()) {
578 MSD.SectionIndex = 0;
579 UndefinedSymbolData.push_back(MSD);
580 } else if (Symbol.isAbsolute()) {
581 MSD.SectionIndex = 0;
582 ExternalSymbolData.push_back(MSD);
583 } else {
584 MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
585 assert(MSD.SectionIndex && "Invalid section index!");
586 ExternalSymbolData.push_back(MSD);
587 }
588 }
589
590 // Now add the data for local symbols.
Duncan P. N. Exon Smithf48de1c2015-05-16 00:35:24 +0000591 for (const MCSymbol &Symbol : Asm.symbols()) {
592 MCSymbolData &SD = Symbol.getData();
Bill Wendlingeb872e02011-06-22 21:07:27 +0000593
594 // Ignore non-linker visible symbols.
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000595 if (!Asm.isSymbolLinkerVisible(Symbol))
Bill Wendlingeb872e02011-06-22 21:07:27 +0000596 continue;
597
David Blaikie583a31c2014-04-18 18:24:25 +0000598 if (SD.isExternal() || Symbol.isUndefined())
Bill Wendlingeb872e02011-06-22 21:07:27 +0000599 continue;
600
Bill Wendlingeb872e02011-06-22 21:07:27 +0000601 MachSymbolData MSD;
Duncan P. N. Exon Smith08b87262015-05-20 15:16:14 +0000602 MSD.Symbol = &Symbol;
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000603 MSD.StringIndex = StringTable.getOffset(Symbol.getName());
Bill Wendlingeb872e02011-06-22 21:07:27 +0000604
605 if (Symbol.isAbsolute()) {
606 MSD.SectionIndex = 0;
607 LocalSymbolData.push_back(MSD);
608 } else {
609 MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
610 assert(MSD.SectionIndex && "Invalid section index!");
611 LocalSymbolData.push_back(MSD);
612 }
613 }
614
615 // External and undefined symbols are required to be in lexicographic order.
616 std::sort(ExternalSymbolData.begin(), ExternalSymbolData.end());
617 std::sort(UndefinedSymbolData.begin(), UndefinedSymbolData.end());
618
619 // Set the symbol indices.
620 Index = 0;
621 for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i)
Duncan P. N. Exon Smith1247bbd2015-05-22 05:54:01 +0000622 LocalSymbolData[i].Symbol->setIndex(Index++);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000623 for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
Duncan P. N. Exon Smith1247bbd2015-05-22 05:54:01 +0000624 ExternalSymbolData[i].Symbol->setIndex(Index++);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000625 for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
Duncan P. N. Exon Smith1247bbd2015-05-22 05:54:01 +0000626 UndefinedSymbolData[i].Symbol->setIndex(Index++);
Rafael Espindola26585542015-01-19 21:11:14 +0000627
Rafael Espindolaa554c052015-05-25 23:14:17 +0000628 for (const MCSection &Section : Asm) {
Rafael Espindola61e724a2015-05-26 01:15:30 +0000629 std::vector<RelAndSymbol> &Relocs = Relocations[&Section];
Rafael Espindola26585542015-01-19 21:11:14 +0000630 for (RelAndSymbol &Rel : Relocs) {
631 if (!Rel.Sym)
632 continue;
633
634 // Set the Index and the IsExtern bit.
Duncan P. N. Exon Smith1247bbd2015-05-22 05:54:01 +0000635 unsigned Index = Rel.Sym->getIndex();
Rafael Espindola26585542015-01-19 21:11:14 +0000636 assert(isInt<24>(Index));
637 if (IsLittleEndian)
Justin Bognerd4e08a02015-05-14 23:54:49 +0000638 Rel.MRE.r_word1 = (Rel.MRE.r_word1 & (~0U << 24)) | Index | (1 << 27);
Rafael Espindola26585542015-01-19 21:11:14 +0000639 else
640 Rel.MRE.r_word1 = (Rel.MRE.r_word1 & 0xff) | Index << 8 | (1 << 4);
641 }
642 }
Bill Wendlingeb872e02011-06-22 21:07:27 +0000643}
644
645void MachObjectWriter::computeSectionAddresses(const MCAssembler &Asm,
646 const MCAsmLayout &Layout) {
647 uint64_t StartAddress = 0;
648 const SmallVectorImpl<MCSectionData*> &Order = Layout.getSectionOrder();
649 for (int i = 0, n = Order.size(); i != n ; ++i) {
650 const MCSectionData *SD = Order[i];
Rafael Espindola967d6a62015-05-21 21:02:35 +0000651 StartAddress =
652 RoundUpToAlignment(StartAddress, SD->getSection().getAlignment());
Rafael Espindola079027e2015-05-26 00:52:18 +0000653 SectionAddress[&SD->getSection()] = StartAddress;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000654 StartAddress += Layout.getSectionAddressSize(SD);
655
656 // Explicitly pad the section to match the alignment requirements of the
657 // following one. This is for 'gas' compatibility, it shouldn't
658 /// strictly be necessary.
Rafael Espindola61e724a2015-05-26 01:15:30 +0000659 StartAddress += getPaddingSize(&SD->getSection(), Layout);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000660 }
661}
662
Bill Wendling21162212011-06-23 00:09:43 +0000663void MachObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
664 const MCAsmLayout &Layout) {
Bill Wendlingeb872e02011-06-22 21:07:27 +0000665 computeSectionAddresses(Asm, Layout);
666
667 // Create symbol data for any indirect symbols.
668 BindIndirectSymbols(Asm);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000669}
670
Rafael Espindola35d61892015-04-17 21:15:17 +0000671bool MachObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
Duncan P. N. Exon Smithd81ba532015-05-16 01:01:55 +0000672 const MCAssembler &Asm, const MCSymbol &SymA, const MCFragment &FB,
Rafael Espindola35d61892015-04-17 21:15:17 +0000673 bool InSet, bool IsPCRel) const {
Bill Wendlingeb872e02011-06-22 21:07:27 +0000674 if (InSet)
675 return true;
676
677 // The effective address is
678 // addr(atom(A)) + offset(A)
679 // - addr(atom(B)) - offset(B)
680 // and the offsets are not relocatable, so the fixup is fully resolved when
681 // addr(atom(A)) - addr(atom(B)) == 0.
Duncan P. N. Exon Smithd81ba532015-05-16 01:01:55 +0000682 const MCSymbol &SA = findAliasedSymbol(SymA);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000683 const MCSection &SecA = SA.getSection();
Rafael Espindola7549f872015-05-26 00:36:57 +0000684 const MCSection &SecB = *FB.getParent();
Bill Wendlingeb872e02011-06-22 21:07:27 +0000685
686 if (IsPCRel) {
687 // The simple (Darwin, except on x86_64) way of dealing with this was to
688 // assume that any reference to a temporary symbol *must* be a temporary
689 // symbol in the same atom, unless the sections differ. Therefore, any PCrel
690 // relocation to a temporary symbol (in the same section) is fully
691 // resolved. This also works in conjunction with absolutized .set, which
692 // requires the compiler to use .set to absolutize the differences between
693 // symbols which the compiler knows to be assembly time constants, so we
694 // don't need to worry about considering symbol differences fully resolved.
Jim Grosbachd6ae4ba2011-12-07 19:46:59 +0000695 //
696 // If the file isn't using sub-sections-via-symbols, we can make the
697 // same assumptions about any symbol that we normally make about
698 // assembler locals.
Bill Wendlingeb872e02011-06-22 21:07:27 +0000699
Rafael Espindolaa063bdd2014-03-11 21:22:57 +0000700 bool hasReliableSymbolDifference = isX86_64();
701 if (!hasReliableSymbolDifference) {
Jim Grosbach40455072012-01-17 22:14:39 +0000702 if (!SA.isInSection() || &SecA != &SecB ||
Jim Grosbachd4dbd092012-01-18 21:54:12 +0000703 (!SA.isTemporary() &&
Jim Grosbach35bc8f92012-01-24 21:45:25 +0000704 FB.getAtom() != Asm.getSymbolData(SA).getFragment()->getAtom() &&
705 Asm.getSubsectionsViaSymbols()))
Bill Wendlingeb872e02011-06-22 21:07:27 +0000706 return false;
707 return true;
708 }
Kevin Enderby7b46bb82011-09-08 20:53:44 +0000709 // For Darwin x86_64, there is one special case when the reference IsPCRel.
710 // If the fragment with the reference does not have a base symbol but meets
711 // the simple way of dealing with this, in that it is a temporary symbol in
712 // the same atom then it is assumed to be fully resolved. This is needed so
Eric Christopher460be992011-09-08 22:17:40 +0000713 // a relocation entry is not created and so the static linker does not
Kevin Enderby7b46bb82011-09-08 20:53:44 +0000714 // mess up the reference later.
715 else if(!FB.getAtom() &&
716 SA.isTemporary() && SA.isInSection() && &SecA == &SecB){
717 return true;
718 }
Bill Wendlingeb872e02011-06-22 21:07:27 +0000719 } else {
720 if (!TargetObjectWriter->useAggressiveSymbolFolding())
721 return false;
722 }
723
Rafael Espindolabfd0f012014-11-04 22:10:33 +0000724 // If they are not in the same section, we can't compute the diff.
725 if (&SecA != &SecB)
726 return false;
727
Benjamin Kramer91ea5112011-08-12 01:51:29 +0000728 const MCFragment *FA = Asm.getSymbolData(SA).getFragment();
Bill Wendlingeb872e02011-06-22 21:07:27 +0000729
Benjamin Kramer91ea5112011-08-12 01:51:29 +0000730 // Bail if the symbol has no fragment.
731 if (!FA)
732 return false;
733
Bill Wendlingeb872e02011-06-22 21:07:27 +0000734 // If the atoms are the same, they are guaranteed to have the same address.
Duncan P. N. Exon Smith09bfa582015-05-16 00:48:58 +0000735 if (FA->getAtom() == FB.getAtom())
Bill Wendlingeb872e02011-06-22 21:07:27 +0000736 return true;
737
738 // Otherwise, we can't prove this is fully resolved.
739 return false;
740}
741
Eric Christopher460be992011-09-08 22:17:40 +0000742void MachObjectWriter::WriteObject(MCAssembler &Asm,
Jim Grosbach46be3012011-12-06 00:13:09 +0000743 const MCAsmLayout &Layout) {
Rafael Espindola26585542015-01-19 21:11:14 +0000744 // Compute symbol table information and bind symbol indices.
745 ComputeSymbolTable(Asm, LocalSymbolData, ExternalSymbolData,
746 UndefinedSymbolData);
747
Bill Wendlingeb872e02011-06-22 21:07:27 +0000748 unsigned NumSections = Asm.size();
Jim Grosbach448334a2014-03-18 22:09:05 +0000749 const MCAssembler::VersionMinInfoType &VersionInfo =
750 Layout.getAssembler().getVersionMinInfo();
Bill Wendlingeb872e02011-06-22 21:07:27 +0000751
752 // The section data starts after the header, the segment load command (and
753 // section headers) and the symbol table.
754 unsigned NumLoadCommands = 1;
755 uint64_t LoadCommandsSize = is64Bit() ?
Charles Davis8bdfafd2013-09-01 04:28:48 +0000756 sizeof(MachO::segment_command_64) + NumSections * sizeof(MachO::section_64):
757 sizeof(MachO::segment_command) + NumSections * sizeof(MachO::section);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000758
Jim Grosbach448334a2014-03-18 22:09:05 +0000759 // Add the deployment target version info load command size, if used.
760 if (VersionInfo.Major != 0) {
761 ++NumLoadCommands;
762 LoadCommandsSize += sizeof(MachO::version_min_command);
763 }
764
Daniel Dunbareec0f322013-01-18 01:26:07 +0000765 // Add the data-in-code load command size, if used.
766 unsigned NumDataRegions = Asm.getDataRegions().size();
767 if (NumDataRegions) {
768 ++NumLoadCommands;
Charles Davis8bdfafd2013-09-01 04:28:48 +0000769 LoadCommandsSize += sizeof(MachO::linkedit_data_command);
Daniel Dunbareec0f322013-01-18 01:26:07 +0000770 }
771
Tim Northover53d32512014-03-29 07:34:53 +0000772 // Add the loh load command size, if used.
773 uint64_t LOHRawSize = Asm.getLOHContainer().getEmitSize(*this, Layout);
774 uint64_t LOHSize = RoundUpToAlignment(LOHRawSize, is64Bit() ? 8 : 4);
775 if (LOHSize) {
776 ++NumLoadCommands;
777 LoadCommandsSize += sizeof(MachO::linkedit_data_command);
778 }
779
Bill Wendlingeb872e02011-06-22 21:07:27 +0000780 // Add the symbol table load command sizes, if used.
781 unsigned NumSymbols = LocalSymbolData.size() + ExternalSymbolData.size() +
782 UndefinedSymbolData.size();
783 if (NumSymbols) {
784 NumLoadCommands += 2;
Charles Davis8bdfafd2013-09-01 04:28:48 +0000785 LoadCommandsSize += (sizeof(MachO::symtab_command) +
786 sizeof(MachO::dysymtab_command));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000787 }
788
Daniel Dunbareec0f322013-01-18 01:26:07 +0000789 // Add the linker option load commands sizes.
790 const std::vector<std::vector<std::string> > &LinkerOptions =
791 Asm.getLinkerOptions();
792 for (unsigned i = 0, e = LinkerOptions.size(); i != e; ++i) {
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000793 ++NumLoadCommands;
Daniel Dunbar34ea79f2013-01-22 03:42:49 +0000794 LoadCommandsSize += ComputeLinkerOptionsLoadCommandSize(LinkerOptions[i],
795 is64Bit());
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000796 }
Daniel Dunbareec0f322013-01-18 01:26:07 +0000797
Bill Wendlingeb872e02011-06-22 21:07:27 +0000798 // Compute the total size of the section data, as well as its file size and vm
799 // size.
Charles Davis8bdfafd2013-09-01 04:28:48 +0000800 uint64_t SectionDataStart = (is64Bit() ? sizeof(MachO::mach_header_64) :
801 sizeof(MachO::mach_header)) + LoadCommandsSize;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000802 uint64_t SectionDataSize = 0;
803 uint64_t SectionDataFileSize = 0;
804 uint64_t VMSize = 0;
805 for (MCAssembler::const_iterator it = Asm.begin(),
806 ie = Asm.end(); it != ie; ++it) {
Rafael Espindolaa554c052015-05-25 23:14:17 +0000807 const MCSectionData &SD = it->getSectionData();
Rafael Espindola079027e2015-05-26 00:52:18 +0000808 uint64_t Address = getSectionAddress(&*it);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000809 uint64_t Size = Layout.getSectionAddressSize(&SD);
810 uint64_t FileSize = Layout.getSectionFileSize(&SD);
Rafael Espindola61e724a2015-05-26 01:15:30 +0000811 FileSize += getPaddingSize(&*it, Layout);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000812
813 VMSize = std::max(VMSize, Address + Size);
814
815 if (SD.getSection().isVirtualSection())
816 continue;
817
818 SectionDataSize = std::max(SectionDataSize, Address + Size);
819 SectionDataFileSize = std::max(SectionDataFileSize, Address + FileSize);
820 }
821
822 // The section data is padded to 4 bytes.
823 //
824 // FIXME: Is this machine dependent?
825 unsigned SectionDataPadding = OffsetToAlignment(SectionDataFileSize, 4);
826 SectionDataFileSize += SectionDataPadding;
827
828 // Write the prolog, starting with the header and load command...
829 WriteHeader(NumLoadCommands, LoadCommandsSize,
830 Asm.getSubsectionsViaSymbols());
831 WriteSegmentLoadCommand(NumSections, VMSize,
832 SectionDataStart, SectionDataSize);
833
834 // ... and then the section headers.
835 uint64_t RelocTableEnd = SectionDataStart + SectionDataFileSize;
836 for (MCAssembler::const_iterator it = Asm.begin(),
837 ie = Asm.end(); it != ie; ++it) {
Rafael Espindola61e724a2015-05-26 01:15:30 +0000838 std::vector<RelAndSymbol> &Relocs = Relocations[&*it];
Bill Wendlingeb872e02011-06-22 21:07:27 +0000839 unsigned NumRelocs = Relocs.size();
Rafael Espindola079027e2015-05-26 00:52:18 +0000840 uint64_t SectionStart = SectionDataStart + getSectionAddress(&*it);
Rafael Espindola61e724a2015-05-26 01:15:30 +0000841 WriteSection(Asm, Layout, *it, SectionStart, RelocTableEnd, NumRelocs);
Charles Davis8bdfafd2013-09-01 04:28:48 +0000842 RelocTableEnd += NumRelocs * sizeof(MachO::any_relocation_info);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000843 }
844
Jim Grosbach448334a2014-03-18 22:09:05 +0000845 // Write out the deployment target information, if it's available.
846 if (VersionInfo.Major != 0) {
847 assert(VersionInfo.Update < 256 && "unencodable update target version");
848 assert(VersionInfo.Minor < 256 && "unencodable minor target version");
849 assert(VersionInfo.Major < 65536 && "unencodable major target version");
850 uint32_t EncodedVersion = VersionInfo.Update | (VersionInfo.Minor << 8) |
851 (VersionInfo.Major << 16);
852 Write32(VersionInfo.Kind == MCVM_OSXVersionMin ? MachO::LC_VERSION_MIN_MACOSX :
853 MachO::LC_VERSION_MIN_IPHONEOS);
854 Write32(sizeof(MachO::version_min_command));
855 Write32(EncodedVersion);
856 Write32(0); // reserved.
857 }
858
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000859 // Write the data-in-code load command, if used.
860 uint64_t DataInCodeTableEnd = RelocTableEnd + NumDataRegions * 8;
861 if (NumDataRegions) {
862 uint64_t DataRegionsOffset = RelocTableEnd;
863 uint64_t DataRegionsSize = NumDataRegions * 8;
Charles Davis8bdfafd2013-09-01 04:28:48 +0000864 WriteLinkeditLoadCommand(MachO::LC_DATA_IN_CODE, DataRegionsOffset,
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000865 DataRegionsSize);
866 }
867
Tim Northover53d32512014-03-29 07:34:53 +0000868 // Write the loh load command, if used.
869 uint64_t LOHTableEnd = DataInCodeTableEnd + LOHSize;
870 if (LOHSize)
871 WriteLinkeditLoadCommand(MachO::LC_LINKER_OPTIMIZATION_HINT,
872 DataInCodeTableEnd, LOHSize);
873
Bill Wendlingeb872e02011-06-22 21:07:27 +0000874 // Write the symbol table load command, if used.
875 if (NumSymbols) {
876 unsigned FirstLocalSymbol = 0;
877 unsigned NumLocalSymbols = LocalSymbolData.size();
878 unsigned FirstExternalSymbol = FirstLocalSymbol + NumLocalSymbols;
879 unsigned NumExternalSymbols = ExternalSymbolData.size();
880 unsigned FirstUndefinedSymbol = FirstExternalSymbol + NumExternalSymbols;
881 unsigned NumUndefinedSymbols = UndefinedSymbolData.size();
882 unsigned NumIndirectSymbols = Asm.indirect_symbol_size();
883 unsigned NumSymTabSymbols =
884 NumLocalSymbols + NumExternalSymbols + NumUndefinedSymbols;
885 uint64_t IndirectSymbolSize = NumIndirectSymbols * 4;
886 uint64_t IndirectSymbolOffset = 0;
887
888 // If used, the indirect symbols are written after the section data.
889 if (NumIndirectSymbols)
Tim Northover53d32512014-03-29 07:34:53 +0000890 IndirectSymbolOffset = LOHTableEnd;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000891
892 // The symbol table is written after the indirect symbol data.
Tim Northover53d32512014-03-29 07:34:53 +0000893 uint64_t SymbolTableOffset = LOHTableEnd + IndirectSymbolSize;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000894
895 // The string table is written after symbol table.
896 uint64_t StringTableOffset =
Charles Davis8bdfafd2013-09-01 04:28:48 +0000897 SymbolTableOffset + NumSymTabSymbols * (is64Bit() ?
898 sizeof(MachO::nlist_64) :
899 sizeof(MachO::nlist));
Bill Wendlingeb872e02011-06-22 21:07:27 +0000900 WriteSymtabLoadCommand(SymbolTableOffset, NumSymTabSymbols,
Hans Wennborg1b1a3992014-10-06 17:05:19 +0000901 StringTableOffset, StringTable.data().size());
Bill Wendlingeb872e02011-06-22 21:07:27 +0000902
903 WriteDysymtabLoadCommand(FirstLocalSymbol, NumLocalSymbols,
904 FirstExternalSymbol, NumExternalSymbols,
905 FirstUndefinedSymbol, NumUndefinedSymbols,
906 IndirectSymbolOffset, NumIndirectSymbols);
907 }
908
Daniel Dunbareec0f322013-01-18 01:26:07 +0000909 // Write the linker options load commands.
910 for (unsigned i = 0, e = LinkerOptions.size(); i != e; ++i) {
911 WriteLinkerOptionsLoadCommand(LinkerOptions[i]);
912 }
913
Bill Wendlingeb872e02011-06-22 21:07:27 +0000914 // Write the actual section data.
915 for (MCAssembler::const_iterator it = Asm.begin(),
916 ie = Asm.end(); it != ie; ++it) {
Rafael Espindolaa554c052015-05-25 23:14:17 +0000917 const MCSectionData &SD = it->getSectionData();
918 Asm.writeSectionData(&SD, Layout);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000919
Rafael Espindola61e724a2015-05-26 01:15:30 +0000920 uint64_t Pad = getPaddingSize(&*it, Layout);
Benjamin Kramer97fbdd52015-04-17 11:12:43 +0000921 WriteZeros(Pad);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000922 }
923
924 // Write the extra padding.
925 WriteZeros(SectionDataPadding);
926
927 // Write the relocation entries.
928 for (MCAssembler::const_iterator it = Asm.begin(),
929 ie = Asm.end(); it != ie; ++it) {
930 // Write the section relocation entries, in reverse order to match 'as'
931 // (approximately, the exact algorithm is more complicated than this).
Rafael Espindola61e724a2015-05-26 01:15:30 +0000932 std::vector<RelAndSymbol> &Relocs = Relocations[&*it];
Bill Wendlingeb872e02011-06-22 21:07:27 +0000933 for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
Rafael Espindola26585542015-01-19 21:11:14 +0000934 Write32(Relocs[e - i - 1].MRE.r_word0);
935 Write32(Relocs[e - i - 1].MRE.r_word1);
Bill Wendlingeb872e02011-06-22 21:07:27 +0000936 }
937 }
938
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000939 // Write out the data-in-code region payload, if there is one.
940 for (MCAssembler::const_data_region_iterator
941 it = Asm.data_region_begin(), ie = Asm.data_region_end();
942 it != ie; ++it) {
943 const DataRegionData *Data = &(*it);
Duncan P. N. Exon Smith99d8a8e2015-05-20 00:02:39 +0000944 uint64_t Start = getSymbolAddress(*Data->Start, Layout);
945 uint64_t End = getSymbolAddress(*Data->End, Layout);
Jim Grosbach4b63d2a2012-05-18 19:12:01 +0000946 DEBUG(dbgs() << "data in code region-- kind: " << Data->Kind
947 << " start: " << Start << "(" << Data->Start->getName() << ")"
948 << " end: " << End << "(" << Data->End->getName() << ")"
949 << " size: " << End - Start
950 << "\n");
951 Write32(Start);
952 Write16(End - Start);
953 Write16(Data->Kind);
954 }
955
Tim Northover53d32512014-03-29 07:34:53 +0000956 // Write out the loh commands, if there is one.
957 if (LOHSize) {
958#ifndef NDEBUG
959 unsigned Start = OS.tell();
960#endif
961 Asm.getLOHContainer().Emit(*this, Layout);
962 // Pad to a multiple of the pointer size.
963 WriteBytes("", OffsetToAlignment(LOHRawSize, is64Bit() ? 8 : 4));
964 assert(OS.tell() - Start == LOHSize);
965 }
966
Bill Wendlingeb872e02011-06-22 21:07:27 +0000967 // Write the symbol table data, if used.
968 if (NumSymbols) {
969 // Write the indirect symbol entries.
970 for (MCAssembler::const_indirect_symbol_iterator
971 it = Asm.indirect_symbol_begin(),
972 ie = Asm.indirect_symbol_end(); it != ie; ++it) {
Alp Tokerf907b892013-12-05 05:44:44 +0000973 // Indirect symbols in the non-lazy symbol pointer section have some
Bill Wendlingeb872e02011-06-22 21:07:27 +0000974 // special handling.
975 const MCSectionMachO &Section =
976 static_cast<const MCSectionMachO&>(it->SectionData->getSection());
David Majnemer7b583052014-03-07 07:36:05 +0000977 if (Section.getType() == MachO::S_NON_LAZY_SYMBOL_POINTERS) {
Bill Wendlingeb872e02011-06-22 21:07:27 +0000978 // If this symbol is defined and internal, mark it as such.
979 if (it->Symbol->isDefined() &&
980 !Asm.getSymbolData(*it->Symbol).isExternal()) {
Charles Davis8bdfafd2013-09-01 04:28:48 +0000981 uint32_t Flags = MachO::INDIRECT_SYMBOL_LOCAL;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000982 if (it->Symbol->isAbsolute())
Charles Davis8bdfafd2013-09-01 04:28:48 +0000983 Flags |= MachO::INDIRECT_SYMBOL_ABS;
Bill Wendlingeb872e02011-06-22 21:07:27 +0000984 Write32(Flags);
985 continue;
986 }
987 }
988
Duncan P. N. Exon Smith1247bbd2015-05-22 05:54:01 +0000989 Write32(it->Symbol->getIndex());
Bill Wendlingeb872e02011-06-22 21:07:27 +0000990 }
991
992 // FIXME: Check that offsets match computed ones.
993
994 // Write the symbol table entries.
995 for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i)
996 WriteNlist(LocalSymbolData[i], Layout);
997 for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
998 WriteNlist(ExternalSymbolData[i], Layout);
999 for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
1000 WriteNlist(UndefinedSymbolData[i], Layout);
1001
1002 // Write the string table.
Hans Wennborg1b1a3992014-10-06 17:05:19 +00001003 OS << StringTable.data();
Bill Wendlingeb872e02011-06-22 21:07:27 +00001004 }
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +00001005}
1006
Daniel Dunbar8888a962010-12-16 16:09:19 +00001007MCObjectWriter *llvm::createMachObjectWriter(MCMachObjectTargetWriter *MOTW,
Rafael Espindola5560a4c2015-04-14 22:14:34 +00001008 raw_pwrite_stream &OS,
Daniel Dunbarfe0c28f2010-11-13 07:33:40 +00001009 bool IsLittleEndian) {
Daniel Dunbar03fcccb2010-12-16 17:21:02 +00001010 return new MachObjectWriter(MOTW, OS, IsLittleEndian);
Daniel Dunbar79e0e5a2010-03-19 10:43:15 +00001011}