mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-24 06:30:19 +00:00
aeed4d81a8
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104793 91177308-0d34-0410-b5e6-96231b3b80d8
1181 lines
42 KiB
C++
1181 lines
42 KiB
C++
//===- lib/MC/MachObjectWriter.cpp - Mach-O File Writer -------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/MC/MachObjectWriter.h"
|
|
#include "llvm/ADT/StringMap.h"
|
|
#include "llvm/ADT/Twine.h"
|
|
#include "llvm/MC/MCAssembler.h"
|
|
#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/MCMachOSymbolFlags.h"
|
|
#include "llvm/MC/MCValue.h"
|
|
#include "llvm/Support/ErrorHandling.h"
|
|
#include "llvm/Support/MachO.h"
|
|
#include "llvm/Target/TargetAsmBackend.h"
|
|
|
|
// FIXME: Gross.
|
|
#include "../Target/X86/X86FixupKinds.h"
|
|
|
|
#include <vector>
|
|
using namespace llvm;
|
|
|
|
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 X86::reloc_riprel_4byte_movq_load:
|
|
case FK_Data_4: return 2;
|
|
case FK_Data_8: return 3;
|
|
}
|
|
}
|
|
|
|
static bool isFixupKindPCRel(unsigned Kind) {
|
|
switch (Kind) {
|
|
default:
|
|
return false;
|
|
case X86::reloc_pcrel_1byte:
|
|
case X86::reloc_pcrel_4byte:
|
|
case X86::reloc_riprel_4byte:
|
|
case X86::reloc_riprel_4byte_movq_load:
|
|
return true;
|
|
}
|
|
}
|
|
|
|
static bool isFixupKindRIPRel(unsigned Kind) {
|
|
return Kind == X86::reloc_riprel_4byte ||
|
|
Kind == X86::reloc_riprel_4byte_movq_load;
|
|
}
|
|
|
|
static bool doesSymbolRequireExternRelocation(MCSymbolData *SD) {
|
|
// Undefined symbols are always extern.
|
|
if (SD->Symbol->isUndefined())
|
|
return true;
|
|
|
|
// References to weak definitions require external relocation entries; the
|
|
// definition may not always be the one in the same object file.
|
|
if (SD->getFlags() & SF_WeakDefinition)
|
|
return true;
|
|
|
|
// Otherwise, we can use an internal relocation.
|
|
return false;
|
|
}
|
|
|
|
namespace {
|
|
|
|
class MachObjectWriterImpl {
|
|
// 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,
|
|
RIT_TLV = 5
|
|
};
|
|
|
|
/// X86_64 uses its own relocation types.
|
|
enum RelocationInfoTypeX86_64 {
|
|
RIT_X86_64_Unsigned = 0,
|
|
RIT_X86_64_Signed = 1,
|
|
RIT_X86_64_Branch = 2,
|
|
RIT_X86_64_GOTLoad = 3,
|
|
RIT_X86_64_GOT = 4,
|
|
RIT_X86_64_Subtractor = 5,
|
|
RIT_X86_64_Signed1 = 6,
|
|
RIT_X86_64_Signed2 = 7,
|
|
RIT_X86_64_Signed4 = 8,
|
|
RIT_X86_64_TLV = 9
|
|
};
|
|
|
|
/// 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 {
|
|
return SymbolData->getSymbol().getName() <
|
|
RHS.SymbolData->getSymbol().getName();
|
|
}
|
|
};
|
|
|
|
/// @name Relocation Data
|
|
/// @{
|
|
|
|
struct MachRelocationEntry {
|
|
uint32_t Word0;
|
|
uint32_t Word1;
|
|
};
|
|
|
|
llvm::DenseMap<const MCSectionData*,
|
|
std::vector<MachRelocationEntry> > Relocations;
|
|
llvm::DenseMap<const MCSectionData*, unsigned> IndirectSymBase;
|
|
|
|
/// @}
|
|
/// @name Symbol Table Data
|
|
/// @{
|
|
|
|
SmallString<256> StringTable;
|
|
std::vector<MachSymbolData> LocalSymbolData;
|
|
std::vector<MachSymbolData> ExternalSymbolData;
|
|
std::vector<MachSymbolData> UndefinedSymbolData;
|
|
|
|
/// @}
|
|
|
|
MachObjectWriter *Writer;
|
|
|
|
raw_ostream &OS;
|
|
|
|
unsigned Is64Bit : 1;
|
|
|
|
public:
|
|
MachObjectWriterImpl(MachObjectWriter *_Writer, bool _Is64Bit)
|
|
: Writer(_Writer), OS(Writer->getStream()), Is64Bit(_Is64Bit) {
|
|
}
|
|
|
|
void Write8(uint8_t Value) { Writer->Write8(Value); }
|
|
void Write16(uint16_t Value) { Writer->Write16(Value); }
|
|
void Write32(uint32_t Value) { Writer->Write32(Value); }
|
|
void Write64(uint64_t Value) { Writer->Write64(Value); }
|
|
void WriteZeros(unsigned N) { Writer->WriteZeros(N); }
|
|
void WriteBytes(StringRef Str, unsigned ZeroFillSize = 0) {
|
|
Writer->WriteBytes(Str, ZeroFillSize);
|
|
}
|
|
|
|
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 MCAsmLayout &Layout,
|
|
const MCSectionData &SD, uint64_t FileOffset,
|
|
uint64_t RelocationsStart, unsigned NumRelocations) {
|
|
uint64_t SectionSize = Layout.getSectionSize(&SD);
|
|
|
|
// The offset is unused for virtual sections.
|
|
if (Asm.getBackend().isVirtualSection(SD.getSection())) {
|
|
assert(Layout.getSectionFileSize(&SD) == 0 && "Invalid file size!");
|
|
FileOffset = 0;
|
|
}
|
|
|
|
// struct section (68 bytes) or
|
|
// struct section_64 (80 bytes)
|
|
|
|
uint64_t Start = OS.tell();
|
|
(void) Start;
|
|
|
|
const MCSectionMachO &Section = cast<MCSectionMachO>(SD.getSection());
|
|
WriteBytes(Section.getSectionName(), 16);
|
|
WriteBytes(Section.getSegmentName(), 16);
|
|
if (Is64Bit) {
|
|
Write64(Layout.getSectionAddress(&SD)); // address
|
|
Write64(SectionSize); // size
|
|
} else {
|
|
Write32(Layout.getSectionAddress(&SD)); // address
|
|
Write32(SectionSize); // 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(IndirectSymBase.lookup(&SD)); // 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, const MCAsmLayout &Layout) {
|
|
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()) {
|
|
Address = cast<MCConstantExpr>(Symbol.getVariableValue())->getValue();
|
|
} else {
|
|
Address = Layout.getSymbolAddress(&Data);
|
|
}
|
|
} 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)
|
|
report_fatal_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);
|
|
}
|
|
|
|
// FIXME: We really need to improve the relocation validation. Basically, we
|
|
// want to implement a separate computation which evaluates the relocation
|
|
// entry as the linker would, and verifies that the resultant fixup value is
|
|
// exactly what the encoder wanted. This will catch several classes of
|
|
// problems:
|
|
//
|
|
// - Relocation entry bugs, the two algorithms are unlikely to have the same
|
|
// exact bug.
|
|
//
|
|
// - Relaxation issues, where we forget to relax something.
|
|
//
|
|
// - Input errors, where something cannot be correctly encoded. 'as' allows
|
|
// these through in many cases.
|
|
|
|
void RecordX86_64Relocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
|
|
const MCFragment *Fragment,
|
|
const MCFixup &Fixup, MCValue Target,
|
|
uint64_t &FixedValue) {
|
|
unsigned IsPCRel = isFixupKindPCRel(Fixup.getKind());
|
|
unsigned IsRIPRel = isFixupKindRIPRel(Fixup.getKind());
|
|
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
|
|
|
|
// See <reloc.h>.
|
|
uint32_t FixupOffset =
|
|
Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
|
|
uint32_t FixupAddress =
|
|
Layout.getFragmentAddress(Fragment) + Fixup.getOffset();
|
|
int64_t Value = 0;
|
|
unsigned Index = 0;
|
|
unsigned IsExtern = 0;
|
|
unsigned Type = 0;
|
|
|
|
Value = Target.getConstant();
|
|
|
|
if (IsPCRel) {
|
|
// Compensate for the relocation offset, Darwin x86_64 relocations only
|
|
// have the addend and appear to have attempted to define it to be the
|
|
// actual expression addend without the PCrel bias. However, instructions
|
|
// with data following the relocation are not accomodated for (see comment
|
|
// below regarding SIGNED{1,2,4}), so it isn't exactly that either.
|
|
Value += 1LL << Log2Size;
|
|
}
|
|
|
|
if (Target.isAbsolute()) { // constant
|
|
// SymbolNum of 0 indicates the absolute section.
|
|
Type = RIT_X86_64_Unsigned;
|
|
Index = 0;
|
|
|
|
// FIXME: I believe this is broken, I don't think the linker can
|
|
// understand it. I think it would require a local relocation, but I'm not
|
|
// sure if that would work either. The official way to get an absolute
|
|
// PCrel relocation is to use an absolute symbol (which we don't support
|
|
// yet).
|
|
if (IsPCRel) {
|
|
IsExtern = 1;
|
|
Type = RIT_X86_64_Branch;
|
|
}
|
|
} else if (Target.getSymB()) { // A - B + constant
|
|
const MCSymbol *A = &Target.getSymA()->getSymbol();
|
|
MCSymbolData &A_SD = Asm.getSymbolData(*A);
|
|
const MCSymbolData *A_Base = Asm.getAtom(Layout, &A_SD);
|
|
|
|
const MCSymbol *B = &Target.getSymB()->getSymbol();
|
|
MCSymbolData &B_SD = Asm.getSymbolData(*B);
|
|
const MCSymbolData *B_Base = Asm.getAtom(Layout, &B_SD);
|
|
|
|
// Neither symbol can be modified.
|
|
if (Target.getSymA()->getKind() != MCSymbolRefExpr::VK_None ||
|
|
Target.getSymB()->getKind() != MCSymbolRefExpr::VK_None)
|
|
report_fatal_error("unsupported relocation of modified symbol");
|
|
|
|
// We don't support PCrel relocations of differences. Darwin 'as' doesn't
|
|
// implement most of these correctly.
|
|
if (IsPCRel)
|
|
report_fatal_error("unsupported pc-relative relocation of difference");
|
|
|
|
// We don't currently support any situation where one or both of the
|
|
// symbols would require a local relocation. This is almost certainly
|
|
// unused and may not be possible to encode correctly.
|
|
if (!A_Base || !B_Base)
|
|
report_fatal_error("unsupported local relocations in difference");
|
|
|
|
// Darwin 'as' doesn't emit correct relocations for this (it ends up with
|
|
// a single SIGNED relocation); reject it for now.
|
|
if (A_Base == B_Base)
|
|
report_fatal_error("unsupported relocation with identical base");
|
|
|
|
Value += Layout.getSymbolAddress(&A_SD) - Layout.getSymbolAddress(A_Base);
|
|
Value -= Layout.getSymbolAddress(&B_SD) - Layout.getSymbolAddress(B_Base);
|
|
|
|
Index = A_Base->getIndex();
|
|
IsExtern = 1;
|
|
Type = RIT_X86_64_Unsigned;
|
|
|
|
MachRelocationEntry MRE;
|
|
MRE.Word0 = FixupOffset;
|
|
MRE.Word1 = ((Index << 0) |
|
|
(IsPCRel << 24) |
|
|
(Log2Size << 25) |
|
|
(IsExtern << 27) |
|
|
(Type << 28));
|
|
Relocations[Fragment->getParent()].push_back(MRE);
|
|
|
|
Index = B_Base->getIndex();
|
|
IsExtern = 1;
|
|
Type = RIT_X86_64_Subtractor;
|
|
} else {
|
|
const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
|
|
MCSymbolData &SD = Asm.getSymbolData(*Symbol);
|
|
const MCSymbolData *Base = Asm.getAtom(Layout, &SD);
|
|
|
|
// Relocations inside debug sections always use local relocations when
|
|
// possible. This seems to be done because the debugger doesn't fully
|
|
// understand x86_64 relocation entries, and expects to find values that
|
|
// have already been fixed up.
|
|
if (Symbol->isInSection()) {
|
|
const MCSectionMachO &Section = static_cast<const MCSectionMachO&>(
|
|
Fragment->getParent()->getSection());
|
|
if (Section.hasAttribute(MCSectionMachO::S_ATTR_DEBUG))
|
|
Base = 0;
|
|
}
|
|
|
|
// x86_64 almost always uses external relocations, except when there is no
|
|
// symbol to use as a base address (a local symbol with no preceeding
|
|
// non-local symbol).
|
|
if (Base) {
|
|
Index = Base->getIndex();
|
|
IsExtern = 1;
|
|
|
|
// Add the local offset, if needed.
|
|
if (Base != &SD)
|
|
Value += Layout.getSymbolAddress(&SD) - Layout.getSymbolAddress(Base);
|
|
} else if (Symbol->isInSection()) {
|
|
// The index is the section ordinal (1-based).
|
|
Index = SD.getFragment()->getParent()->getOrdinal() + 1;
|
|
IsExtern = 0;
|
|
Value += Layout.getSymbolAddress(&SD);
|
|
|
|
if (IsPCRel)
|
|
Value -= FixupAddress + (1 << Log2Size);
|
|
} else {
|
|
report_fatal_error("unsupported relocation of undefined symbol '" +
|
|
Symbol->getName() + "'");
|
|
}
|
|
|
|
MCSymbolRefExpr::VariantKind Modifier = Target.getSymA()->getKind();
|
|
if (IsPCRel) {
|
|
if (IsRIPRel) {
|
|
if (Modifier == MCSymbolRefExpr::VK_GOTPCREL) {
|
|
// x86_64 distinguishes movq foo@GOTPCREL so that the linker can
|
|
// rewrite the movq to an leaq at link time if the symbol ends up in
|
|
// the same linkage unit.
|
|
if (unsigned(Fixup.getKind()) == X86::reloc_riprel_4byte_movq_load)
|
|
Type = RIT_X86_64_GOTLoad;
|
|
else
|
|
Type = RIT_X86_64_GOT;
|
|
} else if (Modifier == MCSymbolRefExpr::VK_TLVP) {
|
|
Type = RIT_X86_64_TLV;
|
|
} else if (Modifier != MCSymbolRefExpr::VK_None) {
|
|
report_fatal_error("unsupported symbol modifier in relocation");
|
|
} else {
|
|
Type = RIT_X86_64_Signed;
|
|
|
|
// The Darwin x86_64 relocation format has a problem where it cannot
|
|
// encode an address (L<foo> + <constant>) which is outside the atom
|
|
// containing L<foo>. Generally, this shouldn't occur but it does
|
|
// happen when we have a RIPrel instruction with data following the
|
|
// relocation entry (e.g., movb $012, L0(%rip)). Even with the PCrel
|
|
// adjustment Darwin x86_64 uses, the offset is still negative and
|
|
// the linker has no way to recognize this.
|
|
//
|
|
// To work around this, Darwin uses several special relocation types
|
|
// to indicate the offsets. However, the specification or
|
|
// implementation of these seems to also be incomplete; they should
|
|
// adjust the addend as well based on the actual encoded instruction
|
|
// (the additional bias), but instead appear to just look at the
|
|
// final offset.
|
|
switch (-(Target.getConstant() + (1LL << Log2Size))) {
|
|
case 1: Type = RIT_X86_64_Signed1; break;
|
|
case 2: Type = RIT_X86_64_Signed2; break;
|
|
case 4: Type = RIT_X86_64_Signed4; break;
|
|
}
|
|
}
|
|
} else {
|
|
if (Modifier != MCSymbolRefExpr::VK_None)
|
|
report_fatal_error("unsupported symbol modifier in branch "
|
|
"relocation");
|
|
|
|
Type = RIT_X86_64_Branch;
|
|
}
|
|
} else {
|
|
if (Modifier == MCSymbolRefExpr::VK_GOT) {
|
|
Type = RIT_X86_64_GOT;
|
|
} else if (Modifier == MCSymbolRefExpr::VK_GOTPCREL) {
|
|
// GOTPCREL is allowed as a modifier on non-PCrel instructions, in
|
|
// which case all we do is set the PCrel bit in the relocation entry;
|
|
// this is used with exception handling, for example. The source is
|
|
// required to include any necessary offset directly.
|
|
Type = RIT_X86_64_GOT;
|
|
IsPCRel = 1;
|
|
} else if (Modifier == MCSymbolRefExpr::VK_TLVP) {
|
|
report_fatal_error("TLVP symbol modifier should have been rip-rel");
|
|
} else if (Modifier != MCSymbolRefExpr::VK_None)
|
|
report_fatal_error("unsupported symbol modifier in relocation");
|
|
else
|
|
Type = RIT_X86_64_Unsigned;
|
|
}
|
|
}
|
|
|
|
// x86_64 always writes custom values into the fixups.
|
|
FixedValue = Value;
|
|
|
|
// struct relocation_info (8 bytes)
|
|
MachRelocationEntry MRE;
|
|
MRE.Word0 = FixupOffset;
|
|
MRE.Word1 = ((Index << 0) |
|
|
(IsPCRel << 24) |
|
|
(Log2Size << 25) |
|
|
(IsExtern << 27) |
|
|
(Type << 28));
|
|
Relocations[Fragment->getParent()].push_back(MRE);
|
|
}
|
|
|
|
void RecordScatteredRelocation(const MCAssembler &Asm,
|
|
const MCAsmLayout &Layout,
|
|
const MCFragment *Fragment,
|
|
const MCFixup &Fixup, MCValue Target,
|
|
uint64_t &FixedValue) {
|
|
uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
|
|
unsigned IsPCRel = isFixupKindPCRel(Fixup.getKind());
|
|
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
|
|
unsigned Type = RIT_Vanilla;
|
|
|
|
// See <reloc.h>.
|
|
const MCSymbol *A = &Target.getSymA()->getSymbol();
|
|
MCSymbolData *A_SD = &Asm.getSymbolData(*A);
|
|
|
|
if (!A_SD->getFragment())
|
|
report_fatal_error("symbol '" + A->getName() +
|
|
"' can not be undefined in a subtraction expression");
|
|
|
|
uint32_t Value = Layout.getSymbolAddress(A_SD);
|
|
uint32_t Value2 = 0;
|
|
|
|
if (const MCSymbolRefExpr *B = Target.getSymB()) {
|
|
MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
|
|
|
|
if (!B_SD->getFragment())
|
|
report_fatal_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 = Layout.getSymbolAddress(B_SD);
|
|
}
|
|
|
|
// 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 = ((FixupOffset << 0) |
|
|
(Type << 24) |
|
|
(Log2Size << 28) |
|
|
(IsPCRel << 30) |
|
|
RF_Scattered);
|
|
MRE.Word1 = Value;
|
|
Relocations[Fragment->getParent()].push_back(MRE);
|
|
}
|
|
|
|
void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
|
|
const MCFragment *Fragment, const MCFixup &Fixup,
|
|
MCValue Target, uint64_t &FixedValue) {
|
|
if (Is64Bit) {
|
|
RecordX86_64Relocation(Asm, Layout, Fragment, Fixup, Target, FixedValue);
|
|
return;
|
|
}
|
|
|
|
unsigned IsPCRel = isFixupKindPCRel(Fixup.getKind());
|
|
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
|
|
|
|
// If this is a difference or a defined symbol plus an offset, then we need
|
|
// a scattered relocation entry.
|
|
// Differences always require scattered relocations.
|
|
if (Target.getSymB())
|
|
return RecordScatteredRelocation(Asm, Layout, Fragment, Fixup,
|
|
Target, FixedValue);
|
|
|
|
// Get the symbol data, if any.
|
|
MCSymbolData *SD = 0;
|
|
if (Target.getSymA())
|
|
SD = &Asm.getSymbolData(Target.getSymA()->getSymbol());
|
|
|
|
// If this is an internal relocation with an offset, it also needs a
|
|
// scattered relocation entry.
|
|
uint32_t Offset = Target.getConstant();
|
|
if (IsPCRel)
|
|
Offset += 1 << Log2Size;
|
|
if (Offset && SD && !doesSymbolRequireExternRelocation(SD))
|
|
return RecordScatteredRelocation(Asm, Layout, Fragment, Fixup,
|
|
Target, FixedValue);
|
|
|
|
// See <reloc.h>.
|
|
uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
|
|
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 {
|
|
// Check whether we need an external or internal relocation.
|
|
if (doesSymbolRequireExternRelocation(SD)) {
|
|
IsExtern = 1;
|
|
Index = SD->getIndex();
|
|
// For external relocations, make sure to offset the fixup value to
|
|
// compensate for the addend of the symbol address, if it was
|
|
// undefined. This occurs with weak definitions, for example.
|
|
if (!SD->Symbol->isUndefined())
|
|
FixedValue -= Layout.getSymbolAddress(SD);
|
|
Value = 0;
|
|
} else {
|
|
// The index is the section ordinal (1-based).
|
|
Index = SD->getFragment()->getParent()->getOrdinal() + 1;
|
|
Value = Layout.getSymbolAddress(SD);
|
|
}
|
|
|
|
Type = RIT_Vanilla;
|
|
}
|
|
|
|
// struct relocation_info (8 bytes)
|
|
MachRelocationEntry MRE;
|
|
MRE.Word0 = FixupOffset;
|
|
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.
|
|
unsigned IndirectIndex = 0;
|
|
for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
|
|
ie = Asm.indirect_symbol_end(); it != ie; ++it, ++IndirectIndex) {
|
|
const MCSectionMachO &Section =
|
|
cast<MCSectionMachO>(it->SectionData->getSection());
|
|
|
|
if (Section.getType() != MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS)
|
|
continue;
|
|
|
|
// Initialize the section indirect symbol base, if necessary.
|
|
if (!IndirectSymBase.count(it->SectionData))
|
|
IndirectSymBase[it->SectionData] = IndirectIndex;
|
|
|
|
Asm.getOrCreateSymbolData(*it->Symbol);
|
|
}
|
|
|
|
// Then lazy symbol pointers and symbol stubs.
|
|
IndirectIndex = 0;
|
|
for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
|
|
ie = Asm.indirect_symbol_end(); it != ie; ++it, ++IndirectIndex) {
|
|
const MCSectionMachO &Section =
|
|
cast<MCSectionMachO>(it->SectionData->getSection());
|
|
|
|
if (Section.getType() != MCSectionMachO::S_LAZY_SYMBOL_POINTERS &&
|
|
Section.getType() != MCSectionMachO::S_SYMBOL_STUBS)
|
|
continue;
|
|
|
|
// Initialize the section indirect symbol base, if necessary.
|
|
if (!IndirectSymBase.count(it->SectionData))
|
|
IndirectSymBase[it->SectionData] = IndirectIndex;
|
|
|
|
// 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';
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
void WriteObject(const MCAssembler &Asm, const MCAsmLayout &Layout) {
|
|
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;
|
|
uint64_t Address = Layout.getSectionAddress(&SD);
|
|
uint64_t Size = Layout.getSectionSize(&SD);
|
|
uint64_t FileSize = Layout.getSectionFileSize(&SD);
|
|
|
|
VMSize = std::max(VMSize, Address + Size);
|
|
|
|
if (Asm.getBackend().isVirtualSection(SD.getSection()))
|
|
continue;
|
|
|
|
SectionDataSize = std::max(SectionDataSize, Address + Size);
|
|
SectionDataFileSize = std::max(SectionDataFileSize, Address + FileSize);
|
|
}
|
|
|
|
// 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 + Layout.getSectionAddress(it);
|
|
WriteSection(Asm, Layout, *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, Layout, Writer);
|
|
|
|
// 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], Layout);
|
|
for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
|
|
WriteNlist(ExternalSymbolData[i], Layout);
|
|
for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
|
|
WriteNlist(UndefinedSymbolData[i], Layout);
|
|
|
|
// Write the string table.
|
|
OS << StringTable.str();
|
|
}
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
MachObjectWriter::MachObjectWriter(raw_ostream &OS,
|
|
bool Is64Bit,
|
|
bool IsLittleEndian)
|
|
: MCObjectWriter(OS, IsLittleEndian)
|
|
{
|
|
Impl = new MachObjectWriterImpl(this, Is64Bit);
|
|
}
|
|
|
|
MachObjectWriter::~MachObjectWriter() {
|
|
delete (MachObjectWriterImpl*) Impl;
|
|
}
|
|
|
|
void MachObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm) {
|
|
((MachObjectWriterImpl*) Impl)->ExecutePostLayoutBinding(Asm);
|
|
}
|
|
|
|
void MachObjectWriter::RecordRelocation(const MCAssembler &Asm,
|
|
const MCAsmLayout &Layout,
|
|
const MCFragment *Fragment,
|
|
const MCFixup &Fixup, MCValue Target,
|
|
uint64_t &FixedValue) {
|
|
((MachObjectWriterImpl*) Impl)->RecordRelocation(Asm, Layout, Fragment, Fixup,
|
|
Target, FixedValue);
|
|
}
|
|
|
|
void MachObjectWriter::WriteObject(const MCAssembler &Asm,
|
|
const MCAsmLayout &Layout) {
|
|
((MachObjectWriterImpl*) Impl)->WriteObject(Asm, Layout);
|
|
}
|