MC/Mach-O: Move to MachObjectWriter.{h,cpp}.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98952 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index f1847df..6e5f73f 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -12,17 +12,13 @@
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
-#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/SmallString.h"
+#include "llvm/MC/MachObjectWriter.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
-#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/MachO.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetRegistry.h"
@@ -34,8 +30,6 @@
#include <vector>
using namespace llvm;
-class MachObjectWriter;
-
STATISTIC(EmittedFragments, "Number of emitted assembler fragments");
// FIXME FIXME FIXME: There are number of places in this file where we convert
@@ -43,19 +37,6 @@
// object file, which may truncate it. We should detect that truncation where
// invalid and report errors back.
-static unsigned getFixupKindLog2Size(unsigned Kind) {
- switch (Kind) {
- default: llvm_unreachable("invalid fixup kind!");
- case X86::reloc_pcrel_1byte:
- case FK_Data_1: return 0;
- case FK_Data_2: return 1;
- case X86::reloc_pcrel_4byte:
- case X86::reloc_riprel_4byte:
- case FK_Data_4: return 2;
- case FK_Data_8: return 3;
- }
-}
-
static bool isFixupKindPCRel(unsigned Kind) {
switch (Kind) {
default:
@@ -67,806 +48,6 @@
}
}
-class MachObjectWriter : public MCObjectWriter {
- // See <mach-o/loader.h>.
- enum {
- Header_Magic32 = 0xFEEDFACE,
- Header_Magic64 = 0xFEEDFACF
- };
-
- enum {
- Header32Size = 28,
- Header64Size = 32,
- SegmentLoadCommand32Size = 56,
- SegmentLoadCommand64Size = 72,
- Section32Size = 68,
- Section64Size = 80,
- SymtabLoadCommandSize = 24,
- DysymtabLoadCommandSize = 80,
- Nlist32Size = 12,
- Nlist64Size = 16,
- RelocationInfoSize = 8
- };
-
- enum HeaderFileType {
- HFT_Object = 0x1
- };
-
- enum HeaderFlags {
- HF_SubsectionsViaSymbols = 0x2000
- };
-
- enum LoadCommandType {
- LCT_Segment = 0x1,
- LCT_Symtab = 0x2,
- LCT_Dysymtab = 0xb,
- LCT_Segment64 = 0x19
- };
-
- // See <mach-o/nlist.h>.
- enum SymbolTypeType {
- STT_Undefined = 0x00,
- STT_Absolute = 0x02,
- STT_Section = 0x0e
- };
-
- enum SymbolTypeFlags {
- // If any of these bits are set, then the entry is a stab entry number (see
- // <mach-o/stab.h>. Otherwise the other masks apply.
- STF_StabsEntryMask = 0xe0,
-
- STF_TypeMask = 0x0e,
- STF_External = 0x01,
- STF_PrivateExtern = 0x10
- };
-
- /// IndirectSymbolFlags - Flags for encoding special values in the indirect
- /// symbol entry.
- enum IndirectSymbolFlags {
- ISF_Local = 0x80000000,
- ISF_Absolute = 0x40000000
- };
-
- /// RelocationFlags - Special flags for addresses.
- enum RelocationFlags {
- RF_Scattered = 0x80000000
- };
-
- enum RelocationInfoType {
- RIT_Vanilla = 0,
- RIT_Pair = 1,
- RIT_Difference = 2,
- RIT_PreboundLazyPointer = 3,
- RIT_LocalDifference = 4
- };
-
- /// MachSymbolData - Helper struct for containing some precomputed information
- /// on symbols.
- struct MachSymbolData {
- MCSymbolData *SymbolData;
- uint64_t StringIndex;
- uint8_t SectionIndex;
-
- // Support lexicographic sorting.
- bool operator<(const MachSymbolData &RHS) const {
- const std::string &Name = SymbolData->getSymbol().getName();
- return Name < RHS.SymbolData->getSymbol().getName();
- }
- };
-
- unsigned Is64Bit : 1;
-
- /// @name Relocation Data
- /// @{
-
- struct MachRelocationEntry {
- uint32_t Word0;
- uint32_t Word1;
- };
-
- llvm::DenseMap<const MCSectionData*,
- std::vector<MachRelocationEntry> > Relocations;
-
- /// @}
- /// @name Symbol Table Data
-
- SmallString<256> StringTable;
- std::vector<MachSymbolData> LocalSymbolData;
- std::vector<MachSymbolData> ExternalSymbolData;
- std::vector<MachSymbolData> UndefinedSymbolData;
-
- /// @}
-
-public:
- MachObjectWriter(raw_ostream &_OS, bool _Is64Bit, bool _IsLittleEndian = true)
- : MCObjectWriter(_OS, _IsLittleEndian), Is64Bit(_Is64Bit) {
- }
-
- void WriteHeader(unsigned NumLoadCommands, unsigned LoadCommandsSize,
- bool SubsectionsViaSymbols) {
- uint32_t Flags = 0;
-
- if (SubsectionsViaSymbols)
- Flags |= HF_SubsectionsViaSymbols;
-
- // struct mach_header (28 bytes) or
- // struct mach_header_64 (32 bytes)
-
- uint64_t Start = OS.tell();
- (void) Start;
-
- Write32(Is64Bit ? Header_Magic64 : Header_Magic32);
-
- // FIXME: Support cputype.
- Write32(Is64Bit ? MachO::CPUTypeX86_64 : MachO::CPUTypeI386);
- // FIXME: Support cpusubtype.
- Write32(MachO::CPUSubType_I386_ALL);
- Write32(HFT_Object);
- Write32(NumLoadCommands); // Object files have a single load command, the
- // segment.
- Write32(LoadCommandsSize);
- Write32(Flags);
- if (Is64Bit)
- Write32(0); // reserved
-
- assert(OS.tell() - Start == Is64Bit ? Header64Size : Header32Size);
- }
-
- /// WriteSegmentLoadCommand - Write a segment load command.
- ///
- /// \arg NumSections - The number of sections in this segment.
- /// \arg SectionDataSize - The total size of the sections.
- void WriteSegmentLoadCommand(unsigned NumSections,
- uint64_t VMSize,
- uint64_t SectionDataStartOffset,
- uint64_t SectionDataSize) {
- // struct segment_command (56 bytes) or
- // struct segment_command_64 (72 bytes)
-
- uint64_t Start = OS.tell();
- (void) Start;
-
- unsigned SegmentLoadCommandSize = Is64Bit ? SegmentLoadCommand64Size :
- SegmentLoadCommand32Size;
- Write32(Is64Bit ? LCT_Segment64 : LCT_Segment);
- Write32(SegmentLoadCommandSize +
- NumSections * (Is64Bit ? Section64Size : Section32Size));
-
- WriteBytes("", 16);
- if (Is64Bit) {
- Write64(0); // vmaddr
- Write64(VMSize); // vmsize
- Write64(SectionDataStartOffset); // file offset
- Write64(SectionDataSize); // file size
- } else {
- Write32(0); // vmaddr
- Write32(VMSize); // vmsize
- Write32(SectionDataStartOffset); // file offset
- Write32(SectionDataSize); // file size
- }
- Write32(0x7); // maxprot
- Write32(0x7); // initprot
- Write32(NumSections);
- Write32(0); // flags
-
- assert(OS.tell() - Start == SegmentLoadCommandSize);
- }
-
- void WriteSection(const MCAssembler &Asm, const MCSectionData &SD,
- uint64_t FileOffset, uint64_t RelocationsStart,
- unsigned NumRelocations) {
- // The offset is unused for virtual sections.
- if (Asm.getBackend().isVirtualSection(SD.getSection())) {
- assert(SD.getFileSize() == 0 && "Invalid file size!");
- FileOffset = 0;
- }
-
- // struct section (68 bytes) or
- // struct section_64 (80 bytes)
-
- uint64_t Start = OS.tell();
- (void) Start;
-
- // FIXME: cast<> support!
- const MCSectionMachO &Section =
- static_cast<const MCSectionMachO&>(SD.getSection());
- WriteBytes(Section.getSectionName(), 16);
- WriteBytes(Section.getSegmentName(), 16);
- if (Is64Bit) {
- Write64(SD.getAddress()); // address
- Write64(SD.getSize()); // size
- } else {
- Write32(SD.getAddress()); // address
- Write32(SD.getSize()); // size
- }
- Write32(FileOffset);
-
- unsigned Flags = Section.getTypeAndAttributes();
- if (SD.hasInstructions())
- Flags |= MCSectionMachO::S_ATTR_SOME_INSTRUCTIONS;
-
- assert(isPowerOf2_32(SD.getAlignment()) && "Invalid alignment!");
- Write32(Log2_32(SD.getAlignment()));
- Write32(NumRelocations ? RelocationsStart : 0);
- Write32(NumRelocations);
- Write32(Flags);
- Write32(0); // reserved1
- Write32(Section.getStubSize()); // reserved2
- if (Is64Bit)
- Write32(0); // reserved3
-
- assert(OS.tell() - Start == Is64Bit ? Section64Size : Section32Size);
- }
-
- void WriteSymtabLoadCommand(uint32_t SymbolOffset, uint32_t NumSymbols,
- uint32_t StringTableOffset,
- uint32_t StringTableSize) {
- // struct symtab_command (24 bytes)
-
- uint64_t Start = OS.tell();
- (void) Start;
-
- Write32(LCT_Symtab);
- Write32(SymtabLoadCommandSize);
- Write32(SymbolOffset);
- Write32(NumSymbols);
- Write32(StringTableOffset);
- Write32(StringTableSize);
-
- assert(OS.tell() - Start == SymtabLoadCommandSize);
- }
-
- 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) {
- // struct dysymtab_command (80 bytes)
-
- uint64_t Start = OS.tell();
- (void) Start;
-
- Write32(LCT_Dysymtab);
- Write32(DysymtabLoadCommandSize);
- Write32(FirstLocalSymbol);
- Write32(NumLocalSymbols);
- Write32(FirstExternalSymbol);
- Write32(NumExternalSymbols);
- Write32(FirstUndefinedSymbol);
- Write32(NumUndefinedSymbols);
- Write32(0); // tocoff
- Write32(0); // ntoc
- Write32(0); // modtaboff
- Write32(0); // nmodtab
- Write32(0); // extrefsymoff
- Write32(0); // nextrefsyms
- Write32(IndirectSymbolOffset);
- Write32(NumIndirectSymbols);
- Write32(0); // extreloff
- Write32(0); // nextrel
- Write32(0); // locreloff
- Write32(0); // nlocrel
-
- assert(OS.tell() - Start == DysymtabLoadCommandSize);
- }
-
- void WriteNlist(MachSymbolData &MSD) {
- MCSymbolData &Data = *MSD.SymbolData;
- const MCSymbol &Symbol = Data.getSymbol();
- uint8_t Type = 0;
- uint16_t Flags = Data.getFlags();
- uint32_t Address = 0;
-
- // Set the N_TYPE bits. See <mach-o/nlist.h>.
- //
- // FIXME: Are the prebound or indirect fields possible here?
- if (Symbol.isUndefined())
- Type = STT_Undefined;
- else if (Symbol.isAbsolute())
- Type = STT_Absolute;
- else
- Type = STT_Section;
-
- // FIXME: Set STAB bits.
-
- if (Data.isPrivateExtern())
- Type |= STF_PrivateExtern;
-
- // Set external bit.
- if (Data.isExternal() || Symbol.isUndefined())
- Type |= STF_External;
-
- // Compute the symbol address.
- if (Symbol.isDefined()) {
- if (Symbol.isAbsolute()) {
- llvm_unreachable("FIXME: Not yet implemented!");
- } else {
- Address = Data.getAddress();
- }
- } else if (Data.isCommon()) {
- // Common symbols are encoded with the size in the address
- // field, and their alignment in the flags.
- Address = Data.getCommonSize();
-
- // Common alignment is packed into the 'desc' bits.
- if (unsigned Align = Data.getCommonAlignment()) {
- unsigned Log2Size = Log2_32(Align);
- assert((1U << Log2Size) == Align && "Invalid 'common' alignment!");
- if (Log2Size > 15)
- llvm_report_error("invalid 'common' alignment '" +
- Twine(Align) + "'");
- // FIXME: Keep this mask with the SymbolFlags enumeration.
- Flags = (Flags & 0xF0FF) | (Log2Size << 8);
- }
- }
-
- // struct nlist (12 bytes)
-
- Write32(MSD.StringIndex);
- Write8(Type);
- Write8(MSD.SectionIndex);
-
- // The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc'
- // value.
- Write16(Flags);
- if (Is64Bit)
- Write64(Address);
- else
- Write32(Address);
- }
-
- void RecordScatteredRelocation(const MCAssembler &Asm,
- const MCFragment &Fragment,
- const MCAsmFixup &Fixup, MCValue Target,
- uint64_t &FixedValue) {
- uint32_t Address = Fragment.getOffset() + Fixup.Offset;
- unsigned IsPCRel = isFixupKindPCRel(Fixup.Kind);
- unsigned Log2Size = getFixupKindLog2Size(Fixup.Kind);
- unsigned Type = RIT_Vanilla;
-
- // See <reloc.h>.
- const MCSymbol *A = &Target.getSymA()->getSymbol();
- MCSymbolData *A_SD = &Asm.getSymbolData(*A);
-
- if (!A_SD->getFragment())
- llvm_report_error("symbol '" + A->getName() +
- "' can not be undefined in a subtraction expression");
-
- uint32_t Value = A_SD->getAddress();
- uint32_t Value2 = 0;
-
- if (const MCSymbolRefExpr *B = Target.getSymB()) {
- MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
-
- if (!B_SD->getFragment())
- llvm_report_error("symbol '" + B->getSymbol().getName() +
- "' can not be undefined in a subtraction expression");
-
- // Select the appropriate difference relocation type.
- //
- // Note that there is no longer any semantic difference between these two
- // relocation types from the linkers point of view, this is done solely
- // for pedantic compatibility with 'as'.
- Type = A_SD->isExternal() ? RIT_Difference : RIT_LocalDifference;
- Value2 = B_SD->getAddress();
- }
-
- // Relocations are written out in reverse order, so the PAIR comes first.
- if (Type == RIT_Difference || Type == RIT_LocalDifference) {
- MachRelocationEntry MRE;
- MRE.Word0 = ((0 << 0) |
- (RIT_Pair << 24) |
- (Log2Size << 28) |
- (IsPCRel << 30) |
- RF_Scattered);
- MRE.Word1 = Value2;
- Relocations[Fragment.getParent()].push_back(MRE);
- }
-
- MachRelocationEntry MRE;
- MRE.Word0 = ((Address << 0) |
- (Type << 24) |
- (Log2Size << 28) |
- (IsPCRel << 30) |
- RF_Scattered);
- MRE.Word1 = Value;
- Relocations[Fragment.getParent()].push_back(MRE);
- }
-
- virtual void RecordRelocation(const MCAssembler &Asm,
- const MCDataFragment &Fragment,
- const MCAsmFixup &Fixup, MCValue Target,
- uint64_t &FixedValue) {
- unsigned IsPCRel = isFixupKindPCRel(Fixup.Kind);
- unsigned Log2Size = getFixupKindLog2Size(Fixup.Kind);
-
- // If this is a difference or a defined symbol plus an offset, then we need
- // a scattered relocation entry.
- uint32_t Offset = Target.getConstant();
- if (IsPCRel)
- Offset += 1 << Log2Size;
- if (Target.getSymB() ||
- (Target.getSymA() && !Target.getSymA()->getSymbol().isUndefined() &&
- Offset)) {
- RecordScatteredRelocation(Asm, Fragment, Fixup, Target, FixedValue);
- return;
- }
-
- // See <reloc.h>.
- uint32_t Address = Fragment.getOffset() + Fixup.Offset;
- uint32_t Value = 0;
- unsigned Index = 0;
- unsigned IsExtern = 0;
- unsigned Type = 0;
-
- if (Target.isAbsolute()) { // constant
- // SymbolNum of 0 indicates the absolute section.
- //
- // FIXME: Currently, these are never generated (see code below). I cannot
- // find a case where they are actually emitted.
- Type = RIT_Vanilla;
- Value = 0;
- } else {
- const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
- MCSymbolData *SD = &Asm.getSymbolData(*Symbol);
-
- if (Symbol->isUndefined()) {
- IsExtern = 1;
- Index = SD->getIndex();
- Value = 0;
- } else {
- // The index is the section ordinal.
- //
- // FIXME: O(N)
- Index = 1;
- MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end();
- for (; it != ie; ++it, ++Index)
- if (&*it == SD->getFragment()->getParent())
- break;
- assert(it != ie && "Unable to find section index!");
- Value = SD->getAddress();
- }
-
- Type = RIT_Vanilla;
- }
-
- // struct relocation_info (8 bytes)
- MachRelocationEntry MRE;
- MRE.Word0 = Address;
- MRE.Word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (IsExtern << 27) |
- (Type << 28));
- Relocations[Fragment.getParent()].push_back(MRE);
- }
-
- void BindIndirectSymbols(MCAssembler &Asm) {
- // This is the point where 'as' creates actual symbols for indirect symbols
- // (in the following two passes). It would be easier for us to do this
- // sooner when we see the attribute, but that makes getting the order in the
- // symbol table much more complicated than it is worth.
- //
- // FIXME: Revisit this when the dust settles.
-
- // Bind non lazy symbol pointers first.
- for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
- ie = Asm.indirect_symbol_end(); it != ie; ++it) {
- // FIXME: cast<> support!
- const MCSectionMachO &Section =
- static_cast<const MCSectionMachO&>(it->SectionData->getSection());
-
- if (Section.getType() != MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS)
- continue;
-
- Asm.getOrCreateSymbolData(*it->Symbol);
- }
-
- // Then lazy symbol pointers and symbol stubs.
- for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
- ie = Asm.indirect_symbol_end(); it != ie; ++it) {
- // FIXME: cast<> support!
- const MCSectionMachO &Section =
- static_cast<const MCSectionMachO&>(it->SectionData->getSection());
-
- if (Section.getType() != MCSectionMachO::S_LAZY_SYMBOL_POINTERS &&
- Section.getType() != MCSectionMachO::S_SYMBOL_STUBS)
- continue;
-
- // Set the symbol type to undefined lazy, but only on construction.
- //
- // FIXME: Do not hardcode.
- bool Created;
- MCSymbolData &Entry = Asm.getOrCreateSymbolData(*it->Symbol, &Created);
- if (Created)
- Entry.setFlags(Entry.getFlags() | 0x0001);
- }
- }
-
- /// ComputeSymbolTable - Compute the symbol table data
- ///
- /// \param StringTable [out] - The string table data.
- /// \param StringIndexMap [out] - Map from symbol names to offsets in the
- /// string table.
- void ComputeSymbolTable(MCAssembler &Asm, SmallString<256> &StringTable,
- std::vector<MachSymbolData> &LocalSymbolData,
- std::vector<MachSymbolData> &ExternalSymbolData,
- std::vector<MachSymbolData> &UndefinedSymbolData) {
- // Build section lookup table.
- DenseMap<const MCSection*, uint8_t> SectionIndexMap;
- unsigned Index = 1;
- for (MCAssembler::iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it, ++Index)
- SectionIndexMap[&it->getSection()] = Index;
- assert(Index <= 256 && "Too many sections!");
-
- // Index 0 is always the empty string.
- StringMap<uint64_t> StringIndexMap;
- StringTable += '\x00';
-
- // Build the symbol arrays and the string table, but only for non-local
- // symbols.
- //
- // The particular order that we collect the symbols and create the string
- // table, then sort the symbols is chosen to match 'as'. Even though it
- // doesn't matter for correctness, this is important for letting us diff .o
- // files.
- for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
- ie = Asm.symbol_end(); it != ie; ++it) {
- const MCSymbol &Symbol = it->getSymbol();
-
- // Ignore non-linker visible symbols.
- if (!Asm.isSymbolLinkerVisible(it))
- continue;
-
- if (!it->isExternal() && !Symbol.isUndefined())
- continue;
-
- uint64_t &Entry = StringIndexMap[Symbol.getName()];
- if (!Entry) {
- Entry = StringTable.size();
- StringTable += Symbol.getName();
- StringTable += '\x00';
- }
-
- MachSymbolData MSD;
- MSD.SymbolData = it;
- MSD.StringIndex = Entry;
-
- if (Symbol.isUndefined()) {
- MSD.SectionIndex = 0;
- UndefinedSymbolData.push_back(MSD);
- } else if (Symbol.isAbsolute()) {
- MSD.SectionIndex = 0;
- ExternalSymbolData.push_back(MSD);
- } else {
- MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
- assert(MSD.SectionIndex && "Invalid section index!");
- ExternalSymbolData.push_back(MSD);
- }
- }
-
- // Now add the data for local symbols.
- for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
- ie = Asm.symbol_end(); it != ie; ++it) {
- const MCSymbol &Symbol = it->getSymbol();
-
- // Ignore non-linker visible symbols.
- if (!Asm.isSymbolLinkerVisible(it))
- continue;
-
- if (it->isExternal() || Symbol.isUndefined())
- continue;
-
- uint64_t &Entry = StringIndexMap[Symbol.getName()];
- if (!Entry) {
- Entry = StringTable.size();
- StringTable += Symbol.getName();
- StringTable += '\x00';
- }
-
- MachSymbolData MSD;
- MSD.SymbolData = it;
- MSD.StringIndex = Entry;
-
- if (Symbol.isAbsolute()) {
- MSD.SectionIndex = 0;
- LocalSymbolData.push_back(MSD);
- } else {
- MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
- assert(MSD.SectionIndex && "Invalid section index!");
- LocalSymbolData.push_back(MSD);
- }
- }
-
- // External and undefined symbols are required to be in lexicographic order.
- std::sort(ExternalSymbolData.begin(), ExternalSymbolData.end());
- std::sort(UndefinedSymbolData.begin(), UndefinedSymbolData.end());
-
- // Set the symbol indices.
- Index = 0;
- for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i)
- LocalSymbolData[i].SymbolData->setIndex(Index++);
- for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
- ExternalSymbolData[i].SymbolData->setIndex(Index++);
- for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
- UndefinedSymbolData[i].SymbolData->setIndex(Index++);
-
- // The string table is padded to a multiple of 4.
- while (StringTable.size() % 4)
- StringTable += '\x00';
- }
-
- virtual void ExecutePostLayoutBinding(MCAssembler &Asm) {
- // Create symbol data for any indirect symbols.
- BindIndirectSymbols(Asm);
-
- // Compute symbol table information and bind symbol indices.
- ComputeSymbolTable(Asm, StringTable, LocalSymbolData, ExternalSymbolData,
- UndefinedSymbolData);
- }
-
- virtual void WriteObject(const MCAssembler &Asm) {
- unsigned NumSections = Asm.size();
-
- // The section data starts after the header, the segment load command (and
- // section headers) and the symbol table.
- unsigned NumLoadCommands = 1;
- uint64_t LoadCommandsSize = Is64Bit ?
- SegmentLoadCommand64Size + NumSections * Section64Size :
- SegmentLoadCommand32Size + NumSections * Section32Size;
-
- // Add the symbol table load command sizes, if used.
- unsigned NumSymbols = LocalSymbolData.size() + ExternalSymbolData.size() +
- UndefinedSymbolData.size();
- if (NumSymbols) {
- NumLoadCommands += 2;
- LoadCommandsSize += SymtabLoadCommandSize + DysymtabLoadCommandSize;
- }
-
- // Compute the total size of the section data, as well as its file size and
- // vm size.
- uint64_t SectionDataStart = (Is64Bit ? Header64Size : Header32Size)
- + LoadCommandsSize;
- uint64_t SectionDataSize = 0;
- uint64_t SectionDataFileSize = 0;
- uint64_t VMSize = 0;
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- const MCSectionData &SD = *it;
-
- VMSize = std::max(VMSize, SD.getAddress() + SD.getSize());
-
- if (Asm.getBackend().isVirtualSection(SD.getSection()))
- continue;
-
- SectionDataSize = std::max(SectionDataSize,
- SD.getAddress() + SD.getSize());
- SectionDataFileSize = std::max(SectionDataFileSize,
- SD.getAddress() + SD.getFileSize());
- }
-
- // The section data is padded to 4 bytes.
- //
- // FIXME: Is this machine dependent?
- unsigned SectionDataPadding = OffsetToAlignment(SectionDataFileSize, 4);
- SectionDataFileSize += SectionDataPadding;
-
- // Write the prolog, starting with the header and load command...
- WriteHeader(NumLoadCommands, LoadCommandsSize,
- Asm.getSubsectionsViaSymbols());
- WriteSegmentLoadCommand(NumSections, VMSize,
- SectionDataStart, SectionDataSize);
-
- // ... and then the section headers.
- uint64_t RelocTableEnd = SectionDataStart + SectionDataFileSize;
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- std::vector<MachRelocationEntry> &Relocs = Relocations[it];
- unsigned NumRelocs = Relocs.size();
- uint64_t SectionStart = SectionDataStart + it->getAddress();
- WriteSection(Asm, *it, SectionStart, RelocTableEnd, NumRelocs);
- RelocTableEnd += NumRelocs * RelocationInfoSize;
- }
-
- // Write the symbol table load command, if used.
- if (NumSymbols) {
- unsigned FirstLocalSymbol = 0;
- unsigned NumLocalSymbols = LocalSymbolData.size();
- unsigned FirstExternalSymbol = FirstLocalSymbol + NumLocalSymbols;
- unsigned NumExternalSymbols = ExternalSymbolData.size();
- unsigned FirstUndefinedSymbol = FirstExternalSymbol + NumExternalSymbols;
- unsigned NumUndefinedSymbols = UndefinedSymbolData.size();
- unsigned NumIndirectSymbols = Asm.indirect_symbol_size();
- unsigned NumSymTabSymbols =
- NumLocalSymbols + NumExternalSymbols + NumUndefinedSymbols;
- uint64_t IndirectSymbolSize = NumIndirectSymbols * 4;
- uint64_t IndirectSymbolOffset = 0;
-
- // If used, the indirect symbols are written after the section data.
- if (NumIndirectSymbols)
- IndirectSymbolOffset = RelocTableEnd;
-
- // The symbol table is written after the indirect symbol data.
- uint64_t SymbolTableOffset = RelocTableEnd + IndirectSymbolSize;
-
- // The string table is written after symbol table.
- uint64_t StringTableOffset =
- SymbolTableOffset + NumSymTabSymbols * (Is64Bit ? Nlist64Size :
- Nlist32Size);
- WriteSymtabLoadCommand(SymbolTableOffset, NumSymTabSymbols,
- StringTableOffset, StringTable.size());
-
- WriteDysymtabLoadCommand(FirstLocalSymbol, NumLocalSymbols,
- FirstExternalSymbol, NumExternalSymbols,
- FirstUndefinedSymbol, NumUndefinedSymbols,
- IndirectSymbolOffset, NumIndirectSymbols);
- }
-
- // Write the actual section data.
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it)
- Asm.WriteSectionData(it, this);
-
- // Write the extra padding.
- WriteZeros(SectionDataPadding);
-
- // Write the relocation entries.
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- // Write the section relocation entries, in reverse order to match 'as'
- // (approximately, the exact algorithm is more complicated than this).
- std::vector<MachRelocationEntry> &Relocs = Relocations[it];
- for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
- Write32(Relocs[e - i - 1].Word0);
- Write32(Relocs[e - i - 1].Word1);
- }
- }
-
- // Write the symbol table data, if used.
- if (NumSymbols) {
- // Write the indirect symbol entries.
- for (MCAssembler::const_indirect_symbol_iterator
- it = Asm.indirect_symbol_begin(),
- ie = Asm.indirect_symbol_end(); it != ie; ++it) {
- // Indirect symbols in the non lazy symbol pointer section have some
- // special handling.
- const MCSectionMachO &Section =
- static_cast<const MCSectionMachO&>(it->SectionData->getSection());
- if (Section.getType() == MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS) {
- // If this symbol is defined and internal, mark it as such.
- if (it->Symbol->isDefined() &&
- !Asm.getSymbolData(*it->Symbol).isExternal()) {
- uint32_t Flags = ISF_Local;
- if (it->Symbol->isAbsolute())
- Flags |= ISF_Absolute;
- Write32(Flags);
- continue;
- }
- }
-
- Write32(Asm.getSymbolData(*it->Symbol).getIndex());
- }
-
- // FIXME: Check that offsets match computed ones.
-
- // Write the symbol table entries.
- for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i)
- WriteNlist(LocalSymbolData[i]);
- for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
- WriteNlist(ExternalSymbolData[i]);
- for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
- WriteNlist(UndefinedSymbolData[i]);
-
- // Write the string table.
- OS << StringTable.str();
- }
- }
-};
-
/* *** */
MCFragment::MCFragment() : Kind(FragmentType(~0)) {