1 //===- lib/MC/MCAssembler.cpp - Assembler Backend Implementation ----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #define DEBUG_TYPE "assembler"
11 #include "llvm/MC/MCAssembler.h"
12 #include "llvm/MC/MCSectionMachO.h"
13 #include "llvm/Target/TargetMachOWriterInfo.h"
14 #include "llvm/ADT/DenseMap.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/ADT/Statistic.h"
17 #include "llvm/ADT/StringMap.h"
18 #include "llvm/ADT/Twine.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/Support/raw_ostream.h"
24 class MachObjectWriter;
26 STATISTIC(EmittedFragments, "Number of emitted assembler fragments");
28 static void WriteFileData(raw_ostream &OS, const MCSectionData &SD,
29 MachObjectWriter &MOW);
31 class MachObjectWriter {
32 // See <mach-o/loader.h>.
34 Header_Magic32 = 0xFEEDFACE,
35 Header_Magic64 = 0xFEEDFACF
38 static const unsigned Header32Size = 28;
39 static const unsigned Header64Size = 32;
40 static const unsigned SegmentLoadCommand32Size = 56;
41 static const unsigned Section32Size = 68;
42 static const unsigned SymtabLoadCommandSize = 24;
43 static const unsigned DysymtabLoadCommandSize = 80;
44 static const unsigned Nlist32Size = 12;
50 enum LoadCommandType {
56 // See <mach-o/nlist.h>.
63 enum SymbolTypeFlags {
64 // If any of these bits are set, then the entry is a stab entry number (see
65 // <mach-o/stab.h>. Otherwise the other masks apply.
66 STF_StabsEntryMask = 0xe0,
70 STF_PrivateExtern = 0x10
73 /// IndirectSymbolFlags - Flags for encoding special values in the indirect
75 enum IndirectSymbolFlags {
76 ISF_Local = 0x80000000,
77 ISF_Absolute = 0x40000000
80 /// MachSymbolData - Helper struct for containing some precomputed information
82 struct MachSymbolData {
83 MCSymbolData *SymbolData;
87 // Support lexicographic sorting.
88 bool operator<(const MachSymbolData &RHS) const {
89 const std::string &Name = SymbolData->getSymbol().getName();
90 return Name < RHS.SymbolData->getSymbol().getName();
98 MachObjectWriter(raw_ostream &_OS, bool _IsLSB = true)
99 : OS(_OS), IsLSB(_IsLSB) {
102 /// @name Helper Methods
105 void Write8(uint8_t Value) {
109 void Write16(uint16_t Value) {
111 Write8(uint8_t(Value >> 0));
112 Write8(uint8_t(Value >> 8));
114 Write8(uint8_t(Value >> 8));
115 Write8(uint8_t(Value >> 0));
119 void Write32(uint32_t Value) {
121 Write16(uint16_t(Value >> 0));
122 Write16(uint16_t(Value >> 16));
124 Write16(uint16_t(Value >> 16));
125 Write16(uint16_t(Value >> 0));
129 void Write64(uint64_t Value) {
131 Write32(uint32_t(Value >> 0));
132 Write32(uint32_t(Value >> 32));
134 Write32(uint32_t(Value >> 32));
135 Write32(uint32_t(Value >> 0));
139 void WriteZeros(unsigned N) {
140 const char Zeros[16] = { 0 };
142 for (unsigned i = 0, e = N / 16; i != e; ++i)
143 OS << StringRef(Zeros, 16);
145 OS << StringRef(Zeros, N % 16);
148 void WriteString(const StringRef &Str, unsigned ZeroFillSize = 0) {
151 WriteZeros(ZeroFillSize - Str.size());
156 void WriteHeader32(unsigned NumLoadCommands, unsigned LoadCommandsSize) {
157 // struct mach_header (28 bytes)
159 uint64_t Start = OS.tell();
162 Write32(Header_Magic32);
164 // FIXME: Support cputype.
165 Write32(TargetMachOWriterInfo::HDR_CPU_TYPE_I386);
167 // FIXME: Support cpusubtype.
168 Write32(TargetMachOWriterInfo::HDR_CPU_SUBTYPE_I386_ALL);
172 // Object files have a single load command, the segment.
173 Write32(NumLoadCommands);
174 Write32(LoadCommandsSize);
177 assert(OS.tell() - Start == Header32Size);
180 /// WriteSegmentLoadCommand32 - Write a 32-bit segment load command.
182 /// \arg NumSections - The number of sections in this segment.
183 /// \arg SectionDataSize - The total size of the sections.
184 void WriteSegmentLoadCommand32(unsigned NumSections,
185 uint64_t SectionDataStartOffset,
186 uint64_t SectionDataSize) {
187 // struct segment_command (56 bytes)
189 uint64_t Start = OS.tell();
192 Write32(LCT_Segment);
193 Write32(SegmentLoadCommand32Size + NumSections * Section32Size);
196 Write32(0); // vmaddr
197 Write32(SectionDataSize); // vmsize
198 Write32(SectionDataStartOffset); // file offset
199 Write32(SectionDataSize); // file size
200 Write32(0x7); // maxprot
201 Write32(0x7); // initprot
202 Write32(NumSections);
205 assert(OS.tell() - Start == SegmentLoadCommand32Size);
208 void WriteSection32(const MCSectionData &SD, uint64_t FileOffset) {
209 // struct section (68 bytes)
211 uint64_t Start = OS.tell();
214 // FIXME: cast<> support!
215 const MCSectionMachO &Section =
216 static_cast<const MCSectionMachO&>(SD.getSection());
217 WriteString(Section.getSectionName(), 16);
218 WriteString(Section.getSegmentName(), 16);
219 Write32(0); // address
220 Write32(SD.getFileSize()); // size
223 assert(isPowerOf2_32(SD.getAlignment()) && "Invalid alignment!");
224 Write32(Log2_32(SD.getAlignment()));
225 Write32(0); // file offset of relocation entries
226 Write32(0); // number of relocation entrions
227 Write32(Section.getTypeAndAttributes());
228 Write32(0); // reserved1
229 Write32(Section.getStubSize()); // reserved2
231 assert(OS.tell() - Start == Section32Size);
234 void WriteSymtabLoadCommand(uint32_t SymbolOffset, uint32_t NumSymbols,
235 uint32_t StringTableOffset,
236 uint32_t StringTableSize) {
237 // struct symtab_command (24 bytes)
239 uint64_t Start = OS.tell();
243 Write32(SymtabLoadCommandSize);
244 Write32(SymbolOffset);
246 Write32(StringTableOffset);
247 Write32(StringTableSize);
249 assert(OS.tell() - Start == SymtabLoadCommandSize);
252 void WriteDysymtabLoadCommand(uint32_t FirstLocalSymbol,
253 uint32_t NumLocalSymbols,
254 uint32_t FirstExternalSymbol,
255 uint32_t NumExternalSymbols,
256 uint32_t FirstUndefinedSymbol,
257 uint32_t NumUndefinedSymbols,
258 uint32_t IndirectSymbolOffset,
259 uint32_t NumIndirectSymbols) {
260 // struct dysymtab_command (80 bytes)
262 uint64_t Start = OS.tell();
265 Write32(LCT_Dysymtab);
266 Write32(DysymtabLoadCommandSize);
267 Write32(FirstLocalSymbol);
268 Write32(NumLocalSymbols);
269 Write32(FirstExternalSymbol);
270 Write32(NumExternalSymbols);
271 Write32(FirstUndefinedSymbol);
272 Write32(NumUndefinedSymbols);
273 Write32(0); // tocoff
275 Write32(0); // modtaboff
276 Write32(0); // nmodtab
277 Write32(0); // extrefsymoff
278 Write32(0); // nextrefsyms
279 Write32(IndirectSymbolOffset);
280 Write32(NumIndirectSymbols);
281 Write32(0); // extreloff
282 Write32(0); // nextrel
283 Write32(0); // locreloff
284 Write32(0); // nlocrel
286 assert(OS.tell() - Start == DysymtabLoadCommandSize);
289 void WriteNlist32(MachSymbolData &MSD) {
290 MCSymbol &Symbol = MSD.SymbolData->getSymbol();
293 // Set the N_TYPE bits. See <mach-o/nlist.h>.
295 // FIXME: Are the prebound or indirect fields possible here?
296 if (Symbol.isUndefined())
297 Type = STT_Undefined;
298 else if (Symbol.isAbsolute())
303 // FIXME: Set STAB bits.
305 if (MSD.SymbolData->isPrivateExtern())
306 Type |= STF_PrivateExtern;
309 if (MSD.SymbolData->isExternal() || Symbol.isUndefined())
310 Type |= STF_External;
312 // struct nlist (12 bytes)
314 Write32(MSD.StringIndex);
316 Write8(MSD.SectionIndex);
318 // The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc'
320 Write16(MSD.SymbolData->getFlags() & 0xFFFF);
322 Write32(0); // FIXME: Value
325 void BindIndirectSymbols(MCAssembler &Asm,
326 DenseMap<MCSymbol*, MCSymbolData*> &SymbolMap) {
327 // This is the point where 'as' creates actual symbols for indirect symbols
328 // (in the following two passes). It would be easier for us to do this
329 // sooner when we see the attribute, but that makes getting the order in the
330 // symbol table much more complicated than it is worth.
332 // FIXME: Revisit this when the dust settles.
334 // Bind non lazy symbol pointers first.
335 for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
336 ie = Asm.indirect_symbol_end(); it != ie; ++it) {
337 // FIXME: cast<> support!
338 const MCSectionMachO &Section =
339 static_cast<const MCSectionMachO&>(it->SectionData->getSection());
342 Section.getTypeAndAttributes() & MCSectionMachO::SECTION_TYPE;
343 if (Type != MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS)
346 MCSymbolData *&Entry = SymbolMap[it->Symbol];
348 Entry = new MCSymbolData(*it->Symbol, 0, 0, &Asm);
351 // Then lazy symbol pointers and symbol stubs.
352 for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
353 ie = Asm.indirect_symbol_end(); it != ie; ++it) {
354 // FIXME: cast<> support!
355 const MCSectionMachO &Section =
356 static_cast<const MCSectionMachO&>(it->SectionData->getSection());
359 Section.getTypeAndAttributes() & MCSectionMachO::SECTION_TYPE;
360 if (Type != MCSectionMachO::S_LAZY_SYMBOL_POINTERS &&
361 Type != MCSectionMachO::S_SYMBOL_STUBS)
364 MCSymbolData *&Entry = SymbolMap[it->Symbol];
366 Entry = new MCSymbolData(*it->Symbol, 0, 0, &Asm);
368 // Set the symbol type to undefined lazy, but only on construction.
370 // FIXME: Do not hardcode.
371 Entry->setFlags(Entry->getFlags() | 0x0001);
376 /// ComputeSymbolTable - Compute the symbol table data
378 /// \param StringTable [out] - The string table data.
379 /// \param StringIndexMap [out] - Map from symbol names to offsets in the
381 void ComputeSymbolTable(MCAssembler &Asm, SmallString<256> &StringTable,
382 std::vector<MachSymbolData> &LocalSymbolData,
383 std::vector<MachSymbolData> &ExternalSymbolData,
384 std::vector<MachSymbolData> &UndefinedSymbolData) {
385 // Build section lookup table.
386 DenseMap<const MCSection*, uint8_t> SectionIndexMap;
388 for (MCAssembler::iterator it = Asm.begin(),
389 ie = Asm.end(); it != ie; ++it, ++Index)
390 SectionIndexMap[&it->getSection()] = Index;
391 assert(Index <= 256 && "Too many sections!");
393 // Index 0 is always the empty string.
394 StringMap<uint64_t> StringIndexMap;
395 StringTable += '\x00';
397 // Build the symbol arrays and the string table, but only for non-local
400 // The particular order that we collect the symbols and create the string
401 // table, then sort the symbols is chosen to match 'as'. Even though it
402 // doesn't matter for correctness, this is important for letting us diff .o
404 for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
405 ie = Asm.symbol_end(); it != ie; ++it) {
406 MCSymbol &Symbol = it->getSymbol();
408 if (!it->isExternal() && !Symbol.isUndefined())
411 uint64_t &Entry = StringIndexMap[Symbol.getName()];
413 Entry = StringTable.size();
414 StringTable += Symbol.getName();
415 StringTable += '\x00';
420 MSD.StringIndex = Entry;
422 if (Symbol.isUndefined()) {
423 MSD.SectionIndex = 0;
424 UndefinedSymbolData.push_back(MSD);
425 } else if (Symbol.isAbsolute()) {
426 MSD.SectionIndex = 0;
427 ExternalSymbolData.push_back(MSD);
429 MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
430 assert(MSD.SectionIndex && "Invalid section index!");
431 ExternalSymbolData.push_back(MSD);
435 // Now add the data for local symbols.
436 for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
437 ie = Asm.symbol_end(); it != ie; ++it) {
438 MCSymbol &Symbol = it->getSymbol();
440 if (it->isExternal() || Symbol.isUndefined())
443 uint64_t &Entry = StringIndexMap[Symbol.getName()];
445 Entry = StringTable.size();
446 StringTable += Symbol.getName();
447 StringTable += '\x00';
452 MSD.StringIndex = Entry;
454 if (Symbol.isAbsolute()) {
455 MSD.SectionIndex = 0;
456 LocalSymbolData.push_back(MSD);
458 MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
459 assert(MSD.SectionIndex && "Invalid section index!");
460 LocalSymbolData.push_back(MSD);
464 // External and undefined symbols are required to be in lexicographic order.
465 std::sort(ExternalSymbolData.begin(), ExternalSymbolData.end());
466 std::sort(UndefinedSymbolData.begin(), UndefinedSymbolData.end());
468 // The string table is padded to a multiple of 4.
470 // FIXME: Check to see if this varies per arch.
471 while (StringTable.size() % 4)
472 StringTable += '\x00';
475 void WriteObject(MCAssembler &Asm) {
476 unsigned NumSections = Asm.size();
478 // Compute the symbol -> symbol data map.
480 // FIXME: This should not be here.
481 DenseMap<MCSymbol*, MCSymbolData *> SymbolMap;
482 for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
483 ie = Asm.symbol_end(); it != ie; ++it)
484 SymbolMap[&it->getSymbol()] = it;
486 // Create symbol data for any indirect symbols.
487 BindIndirectSymbols(Asm, SymbolMap);
489 // Compute symbol table information.
490 SmallString<256> StringTable;
491 std::vector<MachSymbolData> LocalSymbolData;
492 std::vector<MachSymbolData> ExternalSymbolData;
493 std::vector<MachSymbolData> UndefinedSymbolData;
494 unsigned NumSymbols = Asm.symbol_size();
496 // No symbol table command is written if there are no symbols.
498 ComputeSymbolTable(Asm, StringTable, LocalSymbolData, ExternalSymbolData,
499 UndefinedSymbolData);
501 // Compute the file offsets for all the sections in advance, so that we can
502 // write things out in order.
503 SmallVector<uint64_t, 16> SectionFileOffsets;
504 SectionFileOffsets.resize(NumSections);
506 // The section data starts after the header, the segment load command (and
507 // section headers) and the symbol table.
508 unsigned NumLoadCommands = 1;
509 uint64_t LoadCommandsSize =
510 SegmentLoadCommand32Size + NumSections * Section32Size;
512 // Add the symbol table load command sizes, if used.
514 NumLoadCommands += 2;
515 LoadCommandsSize += SymtabLoadCommandSize + DysymtabLoadCommandSize;
518 uint64_t FileOffset = Header32Size + LoadCommandsSize;
519 uint64_t SectionDataStartOffset = FileOffset;
520 uint64_t SectionDataSize = 0;
522 for (MCAssembler::iterator it = Asm.begin(),
523 ie = Asm.end(); it != ie; ++it, ++Index) {
524 SectionFileOffsets[Index] = FileOffset;
525 FileOffset += it->getFileSize();
526 SectionDataSize += it->getFileSize();
529 // Write the prolog, starting with the header and load command...
530 WriteHeader32(NumLoadCommands, LoadCommandsSize);
531 WriteSegmentLoadCommand32(NumSections, SectionDataStartOffset,
534 // ... and then the section headers.
536 for (MCAssembler::iterator it = Asm.begin(),
537 ie = Asm.end(); it != ie; ++it, ++Index)
538 WriteSection32(*it, SectionFileOffsets[Index]);
540 // Write the symbol table load command, if used.
542 unsigned FirstLocalSymbol = 0;
543 unsigned NumLocalSymbols = LocalSymbolData.size();
544 unsigned FirstExternalSymbol = FirstLocalSymbol + NumLocalSymbols;
545 unsigned NumExternalSymbols = ExternalSymbolData.size();
546 unsigned FirstUndefinedSymbol = FirstExternalSymbol + NumExternalSymbols;
547 unsigned NumUndefinedSymbols = UndefinedSymbolData.size();
548 unsigned NumIndirectSymbols = Asm.indirect_symbol_size();
549 unsigned NumSymTabSymbols =
550 NumLocalSymbols + NumExternalSymbols + NumUndefinedSymbols;
551 uint64_t IndirectSymbolSize = NumIndirectSymbols * 4;
552 uint64_t IndirectSymbolOffset = 0;
554 // If used, the indirect symbols are written after the section data.
555 if (NumIndirectSymbols)
556 IndirectSymbolOffset = SectionDataStartOffset + SectionDataSize;
558 // The symbol table is written after the indirect symbol data.
559 uint64_t SymbolTableOffset =
560 SectionDataStartOffset + SectionDataSize + IndirectSymbolSize;
562 // The string table is written after symbol table.
563 uint64_t StringTableOffset =
564 SymbolTableOffset + NumSymTabSymbols * Nlist32Size;
565 WriteSymtabLoadCommand(SymbolTableOffset, NumSymTabSymbols,
566 StringTableOffset, StringTable.size());
568 WriteDysymtabLoadCommand(FirstLocalSymbol, NumLocalSymbols,
569 FirstExternalSymbol, NumExternalSymbols,
570 FirstUndefinedSymbol, NumUndefinedSymbols,
571 IndirectSymbolOffset, NumIndirectSymbols);
574 // Write the actual section data.
575 for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
576 WriteFileData(OS, *it, *this);
578 // Write the symbol table data, if used.
580 // FIXME: We shouldn't need this index table.
581 DenseMap<MCSymbol*, unsigned> SymbolIndexMap;
582 for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i) {
583 MCSymbol &Symbol = LocalSymbolData[i].SymbolData->getSymbol();
584 SymbolIndexMap.insert(std::make_pair(&Symbol, SymbolIndexMap.size()));
586 for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i) {
587 MCSymbol &Symbol = ExternalSymbolData[i].SymbolData->getSymbol();
588 SymbolIndexMap.insert(std::make_pair(&Symbol, SymbolIndexMap.size()));
590 for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i) {
591 MCSymbol &Symbol = UndefinedSymbolData[i].SymbolData->getSymbol();
592 SymbolIndexMap.insert(std::make_pair(&Symbol, SymbolIndexMap.size()));
595 // Write the indirect symbol entries.
597 // FIXME: We need the symbol index map for this.
598 for (MCAssembler::indirect_symbol_iterator
599 it = Asm.indirect_symbol_begin(),
600 ie = Asm.indirect_symbol_end(); it != ie; ++it) {
601 // Indirect symbols in the non lazy symbol pointer section have some
603 const MCSectionMachO &Section =
604 static_cast<const MCSectionMachO&>(it->SectionData->getSection());
606 Section.getTypeAndAttributes() & MCSectionMachO::SECTION_TYPE;
607 if (Type == MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS) {
608 // If this symbol is defined and internal, mark it as such.
609 if (it->Symbol->isDefined() &&
610 !SymbolMap.lookup(it->Symbol)->isExternal()) {
611 uint32_t Flags = ISF_Local;
612 if (it->Symbol->isAbsolute())
613 Flags |= ISF_Absolute;
619 Write32(SymbolIndexMap[it->Symbol]);
622 // FIXME: Check that offsets match computed ones.
624 // Write the symbol table entries.
625 for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i)
626 WriteNlist32(LocalSymbolData[i]);
627 for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
628 WriteNlist32(ExternalSymbolData[i]);
629 for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
630 WriteNlist32(UndefinedSymbolData[i]);
632 // Write the string table.
633 OS << StringTable.str();
640 MCFragment::MCFragment() : Kind(FragmentType(~0)) {
643 MCFragment::MCFragment(FragmentType _Kind, MCSectionData *SD)
645 FileSize(~UINT64_C(0))
648 SD->getFragmentList().push_back(this);
651 MCFragment::~MCFragment() {
656 MCSectionData::MCSectionData() : Section(*(MCSection*)0) {}
658 MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
661 FileSize(~UINT64_C(0))
664 A->getSectionList().push_back(this);
669 MCSymbolData::MCSymbolData() : Symbol(*(MCSymbol*)0) {}
671 MCSymbolData::MCSymbolData(MCSymbol &_Symbol, MCFragment *_Fragment,
672 uint64_t _Offset, MCAssembler *A)
673 : Symbol(_Symbol), Fragment(_Fragment), Offset(_Offset),
674 IsExternal(false), IsPrivateExtern(false), Flags(0)
677 A->getSymbolList().push_back(this);
682 MCAssembler::MCAssembler(raw_ostream &_OS) : OS(_OS) {}
684 MCAssembler::~MCAssembler() {
687 void MCAssembler::LayoutSection(MCSectionData &SD) {
690 for (MCSectionData::iterator it = SD.begin(), ie = SD.end(); it != ie; ++it) {
695 // Evaluate fragment size.
696 switch (F.getKind()) {
697 case MCFragment::FT_Align: {
698 MCAlignFragment &AF = cast<MCAlignFragment>(F);
700 uint64_t AlignedOffset = RoundUpToAlignment(Offset, AF.getAlignment());
701 uint64_t PaddingBytes = AlignedOffset - Offset;
703 if (PaddingBytes > AF.getMaxBytesToEmit())
706 AF.setFileSize(PaddingBytes);
710 case MCFragment::FT_Data:
711 case MCFragment::FT_Fill:
712 F.setFileSize(F.getMaxFileSize());
715 case MCFragment::FT_Org: {
716 MCOrgFragment &OF = cast<MCOrgFragment>(F);
718 if (!OF.getOffset().isAbsolute())
719 llvm_unreachable("FIXME: Not yet implemented!");
720 uint64_t OrgOffset = OF.getOffset().getConstant();
722 // FIXME: We need a way to communicate this error.
723 if (OrgOffset < Offset)
724 llvm_report_error("invalid .org offset '" + Twine(OrgOffset) +
725 "' (section offset '" + Twine(Offset) + "'");
727 F.setFileSize(OrgOffset - Offset);
732 Offset += F.getFileSize();
735 // FIXME: Pad section?
736 SD.setFileSize(Offset);
739 /// WriteFileData - Write the \arg F data to the output file.
740 static void WriteFileData(raw_ostream &OS, const MCFragment &F,
741 MachObjectWriter &MOW) {
742 uint64_t Start = OS.tell();
747 // FIXME: Embed in fragments instead?
748 switch (F.getKind()) {
749 case MCFragment::FT_Align: {
750 MCAlignFragment &AF = cast<MCAlignFragment>(F);
751 uint64_t Count = AF.getFileSize() / AF.getValueSize();
753 // FIXME: This error shouldn't actually occur (the front end should emit
754 // multiple .align directives to enforce the semantics it wants), but is
755 // severe enough that we want to report it. How to handle this?
756 if (Count * AF.getValueSize() != AF.getFileSize())
757 llvm_report_error("undefined .align directive, value size '" +
758 Twine(AF.getValueSize()) +
759 "' is not a divisor of padding size '" +
760 Twine(AF.getFileSize()) + "'");
762 for (uint64_t i = 0; i != Count; ++i) {
763 switch (AF.getValueSize()) {
765 assert(0 && "Invalid size!");
766 case 1: MOW.Write8 (uint8_t (AF.getValue())); break;
767 case 2: MOW.Write16(uint16_t(AF.getValue())); break;
768 case 4: MOW.Write32(uint32_t(AF.getValue())); break;
769 case 8: MOW.Write64(uint64_t(AF.getValue())); break;
775 case MCFragment::FT_Data:
776 OS << cast<MCDataFragment>(F).getContents().str();
779 case MCFragment::FT_Fill: {
780 MCFillFragment &FF = cast<MCFillFragment>(F);
782 if (!FF.getValue().isAbsolute())
783 llvm_unreachable("FIXME: Not yet implemented!");
784 int64_t Value = FF.getValue().getConstant();
786 for (uint64_t i = 0, e = FF.getCount(); i != e; ++i) {
787 switch (FF.getValueSize()) {
789 assert(0 && "Invalid size!");
790 case 1: MOW.Write8 (uint8_t (Value)); break;
791 case 2: MOW.Write16(uint16_t(Value)); break;
792 case 4: MOW.Write32(uint32_t(Value)); break;
793 case 8: MOW.Write64(uint64_t(Value)); break;
799 case MCFragment::FT_Org: {
800 MCOrgFragment &OF = cast<MCOrgFragment>(F);
802 for (uint64_t i = 0, e = OF.getFileSize(); i != e; ++i)
803 MOW.Write8(uint8_t(OF.getValue()));
809 assert(OS.tell() - Start == F.getFileSize());
812 /// WriteFileData - Write the \arg SD data to the output file.
813 static void WriteFileData(raw_ostream &OS, const MCSectionData &SD,
814 MachObjectWriter &MOW) {
815 uint64_t Start = OS.tell();
818 for (MCSectionData::const_iterator it = SD.begin(),
819 ie = SD.end(); it != ie; ++it)
820 WriteFileData(OS, *it, MOW);
822 assert(OS.tell() - Start == SD.getFileSize());
825 void MCAssembler::Finish() {
826 // Layout the sections and fragments.
827 for (iterator it = begin(), ie = end(); it != ie; ++it)
830 // Write the object file.
831 MachObjectWriter MOW(OS);
832 MOW.WriteObject(*this);