//
//===----------------------------------------------------------------------===//
-#include "llvm/MC/MachObjectWriter.h"
+#include "llvm/MC/MCMachObjectWriter.h"
+#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCMachOSymbolFlags.h"
#include "llvm/MC/MCValue.h"
+#include "llvm/Object/MachOFormat.h"
#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/MachO.h"
#include "llvm/Target/TargetAsmBackend.h"
// FIXME: Gross.
#include <vector>
using namespace llvm;
+using namespace llvm::object;
+// FIXME: this has been copied from (or to) X86AsmBackend.cpp
static unsigned getFixupKindLog2Size(unsigned Kind) {
switch (Kind) {
- default: llvm_unreachable("invalid fixup kind!");
- case X86::reloc_pcrel_1byte:
+ // FIXME: Until ARM has it's own relocation stuff spun off, it comes
+ // through here and we don't want it to puke all over. Any reasonable
+ // values will only come when ARM relocation support gets added, at which
+ // point this will be X86 only again and the llvm_unreachable can be
+ // re-enabled.
+ default: return 0;// llvm_unreachable("invalid fixup kind!");
+ case FK_PCRel_1:
case FK_Data_1: return 0;
+ case FK_PCRel_2:
case FK_Data_2: return 1;
- case X86::reloc_pcrel_4byte:
+ case FK_PCRel_4:
case X86::reloc_riprel_4byte:
case X86::reloc_riprel_4byte_movq_load:
+ case X86::reloc_signed_4byte:
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 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
- };
+static bool isScatteredFixupFullyResolved(const MCAssembler &Asm,
+ const MCValue Target,
+ const MCSymbolData *BaseSymbol) {
+ // The effective fixup address is
+ // addr(atom(A)) + offset(A)
+ // - addr(atom(B)) - offset(B)
+ // - addr(BaseSymbol) + <fixup offset from base symbol>
+ // and the offsets are not relocatable, so the fixup is fully resolved when
+ // addr(atom(A)) - addr(atom(B)) - addr(BaseSymbol) == 0.
+ //
+ // Note that "false" is almost always conservatively correct (it means we emit
+ // a relocation which is unnecessary), except when it would force us to emit a
+ // relocation which the target cannot encode.
+
+ const MCSymbolData *A_Base = 0, *B_Base = 0;
+ if (const MCSymbolRefExpr *A = Target.getSymA()) {
+ // Modified symbol references cannot be resolved.
+ if (A->getKind() != MCSymbolRefExpr::VK_None)
+ return false;
+
+ A_Base = Asm.getAtom(&Asm.getSymbolData(A->getSymbol()));
+ if (!A_Base)
+ return false;
+ }
- enum LoadCommandType {
- LCT_Segment = 0x1,
- LCT_Symtab = 0x2,
- LCT_Dysymtab = 0xb,
- LCT_Segment64 = 0x19
- };
+ if (const MCSymbolRefExpr *B = Target.getSymB()) {
+ // Modified symbol references cannot be resolved.
+ if (B->getKind() != MCSymbolRefExpr::VK_None)
+ return false;
- // See <mach-o/nlist.h>.
- enum SymbolTypeType {
- STT_Undefined = 0x00,
- STT_Absolute = 0x02,
- STT_Section = 0x0e
- };
+ B_Base = Asm.getAtom(&Asm.getSymbolData(B->getSymbol()));
+ if (!B_Base)
+ return false;
+ }
- 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,
+ // If there is no base, A and B have to be the same atom for this fixup to be
+ // fully resolved.
+ if (!BaseSymbol)
+ return A_Base == B_Base;
- STF_TypeMask = 0x0e,
- STF_External = 0x01,
- STF_PrivateExtern = 0x10
- };
+ // Otherwise, B must be missing and A must be the base.
+ return !B_Base && BaseSymbol == A_Base;
+}
- /// IndirectSymbolFlags - Flags for encoding special values in the indirect
- /// symbol entry.
- enum IndirectSymbolFlags {
- ISF_Local = 0x80000000,
- ISF_Absolute = 0x40000000
- };
+static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm,
+ const MCValue Target,
+ const MCSection *BaseSection) {
+ // The effective fixup address is
+ // addr(atom(A)) + offset(A)
+ // - addr(atom(B)) - offset(B)
+ // - addr(<base symbol>) + <fixup offset from base symbol>
+ // and the offsets are not relocatable, so the fixup is fully resolved when
+ // addr(atom(A)) - addr(atom(B)) - addr(<base symbol>)) == 0.
+ //
+ // The simple (Darwin, except on x86_64) way of dealing with this was to
+ // assume that any reference to a temporary symbol *must* be a temporary
+ // symbol in the same atom, unless the sections differ. Therefore, any PCrel
+ // relocation to a temporary symbol (in the same section) is fully
+ // resolved. This also works in conjunction with absolutized .set, which
+ // requires the compiler to use .set to absolutize the differences between
+ // symbols which the compiler knows to be assembly time constants, so we don't
+ // need to worry about considering symbol differences fully resolved.
+
+ // Non-relative fixups are only resolved if constant.
+ if (!BaseSection)
+ return Target.isAbsolute();
+
+ // Otherwise, relative fixups are only resolved if not a difference and the
+ // target is a temporary in the same section.
+ if (Target.isAbsolute() || Target.getSymB())
+ return false;
- /// RelocationFlags - Special flags for addresses.
- enum RelocationFlags {
- RF_Scattered = 0x80000000
- };
+ const MCSymbol *A = &Target.getSymA()->getSymbol();
+ if (!A->isTemporary() || !A->isInSection() ||
+ &A->getSection() != BaseSection)
+ return false;
- enum RelocationInfoType {
- RIT_Vanilla = 0,
- RIT_Pair = 1,
- RIT_Difference = 2,
- RIT_PreboundLazyPointer = 3,
- RIT_LocalDifference = 4,
- RIT_TLV = 5
- };
+ return true;
+}
- /// 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
- };
+namespace {
+class MachObjectWriter : public MCObjectWriter {
/// MachSymbolData - Helper struct for containing some precomputed information
/// on symbols.
struct MachSymbolData {
}
};
+ /// The target specific Mach-O writer instance.
+ llvm::OwningPtr<MCMachObjectTargetWriter> TargetObjectWriter;
+
/// @name Relocation Data
/// @{
- struct MachRelocationEntry {
- uint32_t Word0;
- uint32_t Word1;
- };
-
llvm::DenseMap<const MCSectionData*,
- std::vector<MachRelocationEntry> > Relocations;
+ std::vector<macho::RelocationEntry> > Relocations;
llvm::DenseMap<const MCSectionData*, unsigned> IndirectSymBase;
/// @}
/// @}
- MachObjectWriter *Writer;
+private:
+ /// @name Utility Methods
+ /// @{
- raw_ostream &OS;
+ bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
+ const MCFixupKindInfo &FKI = Asm.getBackend().getFixupKindInfo(
+ (MCFixupKind) Kind);
- unsigned Is64Bit : 1;
+ return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel;
+ }
+
+ /// @}
+
+ SectionAddrMap SectionAddress;
+ uint64_t getSectionAddress(const MCSectionData* SD) const {
+ return SectionAddress.lookup(SD);
+ }
+ uint64_t getSymbolAddress(const MCSymbolData* SD,
+ const MCAsmLayout &Layout) const {
+ return getSectionAddress(SD->getFragment()->getParent()) +
+ Layout.getSymbolOffset(SD);
+ }
+ uint64_t getFragmentAddress(const MCFragment *Fragment,
+ const MCAsmLayout &Layout) const {
+ return getSectionAddress(Fragment->getParent()) +
+ Layout.getFragmentOffset(Fragment);
+ }
+
+ uint64_t getPaddingSize(const MCSectionData *SD,
+ const MCAsmLayout &Layout) const {
+ uint64_t EndAddr = getSectionAddress(SD) + Layout.getSectionAddressSize(SD);
+ unsigned Next = SD->getLayoutOrder() + 1;
+ if (Next >= Layout.getSectionOrder().size())
+ return 0;
+
+ const MCSectionData &NextSD = *Layout.getSectionOrder()[Next];
+ if (NextSD.getSection().isVirtualSection())
+ return 0;
+ return OffsetToAlignment(EndAddr, NextSD.getAlignment());
+ }
public:
- MachObjectWriterImpl(MachObjectWriter *_Writer, bool _Is64Bit)
- : Writer(_Writer), OS(Writer->getStream()), Is64Bit(_Is64Bit) {
+ MachObjectWriter(MCMachObjectTargetWriter *MOTW, raw_ostream &_OS,
+ bool _IsLittleEndian)
+ : MCObjectWriter(_OS, _IsLittleEndian), TargetObjectWriter(MOTW) {
}
- 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);
+ /// @name Target Writer Proxy Accessors
+ /// @{
+
+ bool is64Bit() const { return TargetObjectWriter->is64Bit(); }
+ bool isARM() const {
+ uint32_t CPUType = TargetObjectWriter->getCPUType() & mach::CTFM_ArchMask;
+ return CPUType == mach::CTM_ARM;
}
+ /// @}
+
void WriteHeader(unsigned NumLoadCommands, unsigned LoadCommandsSize,
bool SubsectionsViaSymbols) {
uint32_t Flags = 0;
if (SubsectionsViaSymbols)
- Flags |= HF_SubsectionsViaSymbols;
+ Flags |= macho::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);
+ Write32(is64Bit() ? macho::HM_Object64 : macho::HM_Object32);
- // 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(TargetObjectWriter->getCPUType());
+ Write32(TargetObjectWriter->getCPUSubtype());
+
+ Write32(macho::HFT_Object);
+ Write32(NumLoadCommands);
Write32(LoadCommandsSize);
Write32(Flags);
- if (Is64Bit)
+ if (is64Bit())
Write32(0); // reserved
- assert(OS.tell() - Start == Is64Bit ? Header64Size : Header32Size);
+ assert(OS.tell() - Start == is64Bit() ?
+ macho::Header64Size : macho::Header32Size);
}
/// WriteSegmentLoadCommand - Write a segment load command.
uint64_t Start = OS.tell();
(void) Start;
- unsigned SegmentLoadCommandSize = Is64Bit ? SegmentLoadCommand64Size :
- SegmentLoadCommand32Size;
- Write32(Is64Bit ? LCT_Segment64 : LCT_Segment);
+ unsigned SegmentLoadCommandSize =
+ is64Bit() ? macho::SegmentLoadCommand64Size:
+ macho::SegmentLoadCommand32Size;
+ Write32(is64Bit() ? macho::LCT_Segment64 : macho::LCT_Segment);
Write32(SegmentLoadCommandSize +
- NumSections * (Is64Bit ? Section64Size : Section32Size));
+ NumSections * (is64Bit() ? macho::Section64Size :
+ macho::Section32Size));
WriteBytes("", 16);
- if (Is64Bit) {
+ if (is64Bit()) {
Write64(0); // vmaddr
Write64(VMSize); // vmsize
Write64(SectionDataStartOffset); // file offset
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);
+ uint64_t SectionSize = Layout.getSectionAddressSize(&SD);
// The offset is unused for virtual sections.
- if (Asm.getBackend().isVirtualSection(SD.getSection())) {
+ if (SD.getSection().isVirtualSection()) {
assert(Layout.getSectionFileSize(&SD) == 0 && "Invalid file size!");
FileOffset = 0;
}
const MCSectionMachO &Section = cast<MCSectionMachO>(SD.getSection());
WriteBytes(Section.getSectionName(), 16);
WriteBytes(Section.getSegmentName(), 16);
- if (Is64Bit) {
- Write64(Layout.getSectionAddress(&SD)); // address
+ if (is64Bit()) {
+ Write64(getSectionAddress(&SD)); // address
Write64(SectionSize); // size
} else {
- Write32(Layout.getSectionAddress(&SD)); // address
+ Write32(getSectionAddress(&SD)); // address
Write32(SectionSize); // size
}
Write32(FileOffset);
Write32(Flags);
Write32(IndirectSymBase.lookup(&SD)); // reserved1
Write32(Section.getStubSize()); // reserved2
- if (Is64Bit)
+ if (is64Bit())
Write32(0); // reserved3
- assert(OS.tell() - Start == Is64Bit ? Section64Size : Section32Size);
+ assert(OS.tell() - Start == is64Bit() ? macho::Section64Size :
+ macho::Section32Size);
}
void WriteSymtabLoadCommand(uint32_t SymbolOffset, uint32_t NumSymbols,
uint64_t Start = OS.tell();
(void) Start;
- Write32(LCT_Symtab);
- Write32(SymtabLoadCommandSize);
+ Write32(macho::LCT_Symtab);
+ Write32(macho::SymtabLoadCommandSize);
Write32(SymbolOffset);
Write32(NumSymbols);
Write32(StringTableOffset);
Write32(StringTableSize);
- assert(OS.tell() - Start == SymtabLoadCommandSize);
+ assert(OS.tell() - Start == macho::SymtabLoadCommandSize);
}
void WriteDysymtabLoadCommand(uint32_t FirstLocalSymbol,
uint64_t Start = OS.tell();
(void) Start;
- Write32(LCT_Dysymtab);
- Write32(DysymtabLoadCommandSize);
+ Write32(macho::LCT_Dysymtab);
+ Write32(macho::DysymtabLoadCommandSize);
Write32(FirstLocalSymbol);
Write32(NumLocalSymbols);
Write32(FirstExternalSymbol);
Write32(0); // locreloff
Write32(0); // nlocrel
- assert(OS.tell() - Start == DysymtabLoadCommandSize);
+ assert(OS.tell() - Start == macho::DysymtabLoadCommandSize);
}
void WriteNlist(MachSymbolData &MSD, const MCAsmLayout &Layout) {
//
// FIXME: Are the prebound or indirect fields possible here?
if (Symbol.isUndefined())
- Type = STT_Undefined;
+ Type = macho::STT_Undefined;
else if (Symbol.isAbsolute())
- Type = STT_Absolute;
+ Type = macho::STT_Absolute;
else
- Type = STT_Section;
+ Type = macho::STT_Section;
// FIXME: Set STAB bits.
if (Data.isPrivateExtern())
- Type |= STF_PrivateExtern;
+ Type |= macho::STF_PrivateExtern;
// Set external bit.
if (Data.isExternal() || Symbol.isUndefined())
- Type |= STF_External;
+ Type |= macho::STF_External;
// Compute the symbol address.
if (Symbol.isDefined()) {
if (Symbol.isAbsolute()) {
Address = cast<MCConstantExpr>(Symbol.getVariableValue())->getValue();
} else {
- Address = Layout.getSymbolAddress(&Data);
+ Address = getSymbolAddress(&Data, Layout);
}
} else if (Data.isCommon()) {
// Common symbols are encoded with the size in the address
// The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc'
// value.
Write16(Flags);
- if (Is64Bit)
+ if (is64Bit())
Write64(Address);
else
Write32(Address);
// - Input errors, where something cannot be correctly encoded. 'as' allows
// these through in many cases.
+ static bool isFixupKindRIPRel(unsigned Kind) {
+ return Kind == X86::reloc_riprel_4byte ||
+ Kind == X86::reloc_riprel_4byte_movq_load;
+ }
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 IsPCRel = isFixupKindPCRel(Asm, Fixup.getKind());
unsigned IsRIPRel = isFixupKindRIPRel(Fixup.getKind());
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
uint32_t FixupOffset =
Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
uint32_t FixupAddress =
- Layout.getFragmentAddress(Fragment) + Fixup.getOffset();
+ getFragmentAddress(Fragment, Layout) + Fixup.getOffset();
int64_t Value = 0;
unsigned Index = 0;
unsigned IsExtern = 0;
if (Target.isAbsolute()) { // constant
// SymbolNum of 0 indicates the absolute section.
- Type = RIT_X86_64_Unsigned;
+ Type = macho::RIT_X86_64_Unsigned;
Index = 0;
// FIXME: I believe this is broken, I don't think the linker can
// yet).
if (IsPCRel) {
IsExtern = 1;
- Type = RIT_X86_64_Branch;
+ Type = macho::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 MCSymbolData *A_Base = Asm.getAtom(&A_SD);
const MCSymbol *B = &Target.getSymB()->getSymbol();
MCSymbolData &B_SD = Asm.getSymbolData(*B);
- const MCSymbolData *B_Base = Asm.getAtom(Layout, &B_SD);
+ const MCSymbolData *B_Base = Asm.getAtom(&B_SD);
// Neither symbol can be modified.
if (Target.getSymA()->getKind() != MCSymbolRefExpr::VK_None ||
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");
+ // The support for the situation where one or both of the symbols would
+ // require a local relocation is handled just like if the symbols were
+ // external. This is certainly used in the case of debug sections where
+ // the section has only temporary symbols and thus the symbols don't have
+ // base symbols. This is encoded using the section ordinal and
+ // non-extern relocation entries.
// 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)
+ // a single SIGNED relocation); reject it for now. Except the case where
+ // both symbols don't have a base, equal but both NULL.
+ if (A_Base == B_Base && A_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);
+ Value += getSymbolAddress(&A_SD, Layout) -
+ (A_Base == NULL ? 0 : getSymbolAddress(A_Base, Layout));
+ Value -= getSymbolAddress(&B_SD, Layout) -
+ (B_Base == NULL ? 0 : getSymbolAddress(B_Base, Layout));
- Index = A_Base->getIndex();
- IsExtern = 1;
- Type = RIT_X86_64_Unsigned;
+ if (A_Base) {
+ Index = A_Base->getIndex();
+ IsExtern = 1;
+ }
+ else {
+ Index = A_SD.getFragment()->getParent()->getOrdinal() + 1;
+ IsExtern = 0;
+ }
+ Type = macho::RIT_X86_64_Unsigned;
- MachRelocationEntry MRE;
+ macho::RelocationEntry MRE;
MRE.Word0 = FixupOffset;
MRE.Word1 = ((Index << 0) |
(IsPCRel << 24) |
(Type << 28));
Relocations[Fragment->getParent()].push_back(MRE);
- Index = B_Base->getIndex();
- IsExtern = 1;
- Type = RIT_X86_64_Subtractor;
+ if (B_Base) {
+ Index = B_Base->getIndex();
+ IsExtern = 1;
+ }
+ else {
+ Index = B_SD.getFragment()->getParent()->getOrdinal() + 1;
+ IsExtern = 0;
+ }
+ Type = macho::RIT_X86_64_Subtractor;
} else {
const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
MCSymbolData &SD = Asm.getSymbolData(*Symbol);
- const MCSymbolData *Base = Asm.getAtom(Layout, &SD);
+ const MCSymbolData *Base = Asm.getAtom(&SD);
// Relocations inside debug sections always use local relocations when
// possible. This seems to be done because the debugger doesn't fully
// Add the local offset, if needed.
if (Base != &SD)
- Value += Layout.getSymbolAddress(&SD) - Layout.getSymbolAddress(Base);
+ Value += Layout.getSymbolOffset(&SD) - Layout.getSymbolOffset(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);
+ Value += getSymbolAddress(&SD, Layout);
if (IsPCRel)
Value -= FixupAddress + (1 << Log2Size);
+ } else if (Symbol->isVariable()) {
+ const MCExpr *Value = Symbol->getVariableValue();
+ int64_t Res;
+ bool isAbs = Value->EvaluateAsAbsolute(Res, Layout, SectionAddress);
+ if (isAbs) {
+ FixedValue = Res;
+ return;
+ } else {
+ report_fatal_error("unsupported relocation of variable '" +
+ Symbol->getName() + "'");
+ }
} else {
report_fatal_error("unsupported relocation of undefined symbol '" +
Symbol->getName() + "'");
// 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;
+ Type = macho::RIT_X86_64_GOTLoad;
else
- Type = RIT_X86_64_GOT;
+ Type = macho::RIT_X86_64_GOT;
} else if (Modifier == MCSymbolRefExpr::VK_TLVP) {
- Type = RIT_X86_64_TLV;
+ Type = macho::RIT_X86_64_TLV;
} else if (Modifier != MCSymbolRefExpr::VK_None) {
report_fatal_error("unsupported symbol modifier in relocation");
} else {
- Type = RIT_X86_64_Signed;
+ Type = macho::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
// (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;
+ case 1: Type = macho::RIT_X86_64_Signed1; break;
+ case 2: Type = macho::RIT_X86_64_Signed2; break;
+ case 4: Type = macho::RIT_X86_64_Signed4; break;
}
}
} else {
report_fatal_error("unsupported symbol modifier in branch "
"relocation");
- Type = RIT_X86_64_Branch;
+ Type = macho::RIT_X86_64_Branch;
}
} else {
if (Modifier == MCSymbolRefExpr::VK_GOT) {
- Type = RIT_X86_64_GOT;
+ Type = macho::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;
+ Type = macho::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;
+ Type = macho::RIT_X86_64_Unsigned;
}
}
FixedValue = Value;
// struct relocation_info (8 bytes)
- MachRelocationEntry MRE;
+ macho::RelocationEntry MRE;
MRE.Word0 = FixupOffset;
MRE.Word1 = ((Index << 0) |
(IsPCRel << 24) |
const MCFixup &Fixup, MCValue Target,
uint64_t &FixedValue) {
uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
- unsigned IsPCRel = isFixupKindPCRel(Fixup.getKind());
+ unsigned IsPCRel = isFixupKindPCRel(Asm, Fixup.getKind());
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
- unsigned Type = RIT_Vanilla;
+ unsigned Type = macho::RIT_Vanilla;
// See <reloc.h>.
const MCSymbol *A = &Target.getSymA()->getSymbol();
report_fatal_error("symbol '" + A->getName() +
"' can not be undefined in a subtraction expression");
- uint32_t Value = Layout.getSymbolAddress(A_SD);
+ uint32_t Value = getSymbolAddress(A_SD, Layout);
+ uint64_t SecAddr = getSectionAddress(A_SD->getFragment()->getParent());
+ FixedValue += SecAddr;
uint32_t Value2 = 0;
if (const MCSymbolRefExpr *B = Target.getSymB()) {
// 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);
+ Type = A_SD->isExternal() ? (unsigned)macho::RIT_Difference :
+ (unsigned)macho::RIT_Generic_LocalDifference;
+ Value2 = getSymbolAddress(B_SD, Layout);
+ FixedValue -= getSectionAddress(B_SD->getFragment()->getParent());
}
// Relocations are written out in reverse order, so the PAIR comes first.
- if (Type == RIT_Difference || Type == RIT_LocalDifference) {
- MachRelocationEntry MRE;
+ if (Type == macho::RIT_Difference ||
+ Type == macho::RIT_Generic_LocalDifference) {
+ macho::RelocationEntry MRE;
MRE.Word0 = ((0 << 0) |
- (RIT_Pair << 24) |
+ (macho::RIT_Pair << 24) |
(Log2Size << 28) |
(IsPCRel << 30) |
- RF_Scattered);
+ macho::RF_Scattered);
MRE.Word1 = Value2;
Relocations[Fragment->getParent()].push_back(MRE);
}
- MachRelocationEntry MRE;
+ macho::RelocationEntry MRE;
MRE.Word0 = ((FixupOffset << 0) |
(Type << 24) |
(Log2Size << 28) |
(IsPCRel << 30) |
- RF_Scattered);
+ macho::RF_Scattered);
MRE.Word1 = Value;
Relocations[Fragment->getParent()].push_back(MRE);
}
const MCFixup &Fixup, MCValue Target,
uint64_t &FixedValue) {
assert(Target.getSymA()->getKind() == MCSymbolRefExpr::VK_TLVP &&
- !Is64Bit &&
+ !is64Bit() &&
"Should only be called with a 32-bit TLVP relocation!");
- // If this is a subtraction then we're pcrel.
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
uint32_t Value = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
unsigned IsPCRel = 0;
MCSymbolData *SD_A = &Asm.getSymbolData(Target.getSymA()->getSymbol());
unsigned Index = SD_A->getIndex();
- if (Target.getSymB())
+ // We're only going to have a second symbol in pic mode and it'll be a
+ // subtraction from the picbase. For 32-bit pic the addend is the difference
+ // between the picbase and the next address. For 32-bit static the addend
+ // is zero.
+ if (Target.getSymB()) {
+ // If this is a subtraction then we're pcrel.
+ uint32_t FixupAddress =
+ getFragmentAddress(Fragment, Layout) + Fixup.getOffset();
+ MCSymbolData *SD_B = &Asm.getSymbolData(Target.getSymB()->getSymbol());
IsPCRel = 1;
-
+ FixedValue = (FixupAddress - getSymbolAddress(SD_B, Layout) +
+ Target.getConstant());
+ FixedValue += 1ULL << Log2Size;
+ } else {
+ FixedValue = 0;
+ }
+
// struct relocation_info (8 bytes)
- MachRelocationEntry MRE;
+ macho::RelocationEntry MRE;
MRE.Word0 = Value;
- MRE.Word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (1 << 27) | // Extern
- (RIT_TLV << 28)); // Type
+ MRE.Word1 = ((Index << 0) |
+ (IsPCRel << 24) |
+ (Log2Size << 25) |
+ (1 << 27) | // Extern
+ (macho::RIT_Generic_TLV << 28)); // Type
Relocations[Fragment->getParent()].push_back(MRE);
}
-
+
+ void RecordARMRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
+ const MCFragment *Fragment, const MCFixup &Fixup,
+ MCValue Target, uint64_t &FixedValue) {
+ // FIXME!
+ }
+
void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment *Fragment, const MCFixup &Fixup,
MCValue Target, uint64_t &FixedValue) {
- if (Is64Bit) {
+ // FIXME: These needs to be factored into the target Mach-O writer.
+ if (isARM()) {
+ RecordARMRelocation(Asm, Layout, Fragment, Fixup, Target, FixedValue);
+ return;
+ }
+ if (is64Bit()) {
RecordX86_64Relocation(Asm, Layout, Fragment, Fixup, Target, FixedValue);
return;
}
- unsigned IsPCRel = isFixupKindPCRel(Fixup.getKind());
+ unsigned IsPCRel = isFixupKindPCRel(Asm, Fixup.getKind());
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
// If this is a 32-bit TLVP reloc it's handled a bit differently.
- if (Target.getSymA()->getKind() == MCSymbolRefExpr::VK_TLVP) {
+ if (Target.getSymA() &&
+ Target.getSymA()->getKind() == MCSymbolRefExpr::VK_TLVP) {
RecordTLVPRelocation(Asm, Layout, Fragment, Fixup, Target, FixedValue);
return;
}
-
+
// If this is a difference or a defined symbol plus an offset, then we need
// a scattered relocation entry.
// Differences always require scattered relocations.
// See <reloc.h>.
uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
- uint32_t Value = 0;
unsigned Index = 0;
unsigned IsExtern = 0;
unsigned Type = 0;
//
// FIXME: Currently, these are never generated (see code below). I cannot
// find a case where they are actually emitted.
- Type = RIT_Vanilla;
- Value = 0;
+ Type = macho::RIT_Vanilla;
+ } else if (SD->getSymbol().isVariable()) {
+ const MCExpr *Value = SD->getSymbol().getVariableValue();
+ int64_t Res;
+ bool isAbs = Value->EvaluateAsAbsolute(Res, Layout, SectionAddress);
+ if (isAbs) {
+ FixedValue = Res;
+ return;
+ } else {
+ report_fatal_error("unsupported relocation of variable '" +
+ SD->getSymbol().getName() + "'");
+ }
} else {
// Check whether we need an external or internal relocation.
if (doesSymbolRequireExternRelocation(SD)) {
// 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;
+ FixedValue -= Layout.getSymbolOffset(SD);
} else {
// The index is the section ordinal (1-based).
Index = SD->getFragment()->getParent()->getOrdinal() + 1;
- Value = Layout.getSymbolAddress(SD);
+ FixedValue += getSectionAddress(SD->getFragment()->getParent());
}
+ if (IsPCRel)
+ FixedValue -= getSectionAddress(Fragment->getParent());
- Type = RIT_Vanilla;
+ Type = macho::RIT_Vanilla;
}
// struct relocation_info (8 bytes)
- MachRelocationEntry MRE;
+ macho::RelocationEntry MRE;
MRE.Word0 = FixupOffset;
MRE.Word1 = ((Index << 0) |
(IsPCRel << 24) |
// Initialize the section indirect symbol base, if necessary.
if (!IndirectSymBase.count(it->SectionData))
IndirectSymBase[it->SectionData] = IndirectIndex;
-
+
Asm.getOrCreateSymbolData(*it->Symbol);
}
StringTable += '\x00';
}
- void ExecutePostLayoutBinding(MCAssembler &Asm) {
+ void computeSectionAddresses(const MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
+ uint64_t StartAddress = 0;
+ const SmallVectorImpl<MCSectionData*> &Order = Layout.getSectionOrder();
+ for (int i = 0, n = Order.size(); i != n ; ++i) {
+ const MCSectionData *SD = Order[i];
+ StartAddress = RoundUpToAlignment(StartAddress, SD->getAlignment());
+ SectionAddress[SD] = StartAddress;
+ StartAddress += Layout.getSectionAddressSize(SD);
+ // Explicitly pad the section to match the alignment requirements of the
+ // following one. This is for 'gas' compatibility, it shouldn't
+ /// strictly be necessary.
+ StartAddress += getPaddingSize(SD, Layout);
+ }
+ }
+
+ void ExecutePostLayoutBinding(MCAssembler &Asm, const MCAsmLayout &Layout) {
+ computeSectionAddresses(Asm, Layout);
+
// Create symbol data for any indirect symbols.
BindIndirectSymbols(Asm);
UndefinedSymbolData);
}
- void WriteObject(const MCAssembler &Asm, const MCAsmLayout &Layout) {
+ bool IsSymbolRefDifferenceFullyResolved(const MCAssembler &Asm,
+ const MCSymbolRefExpr *A,
+ const MCSymbolRefExpr *B,
+ bool InSet) const {
+ if (InSet)
+ return true;
+
+ if (!TargetObjectWriter->useAggressiveSymbolFolding())
+ return false;
+
+ // The effective address is
+ // addr(atom(A)) + offset(A)
+ // - addr(atom(B)) - offset(B)
+ // and the offsets are not relocatable, so the fixup is fully resolved when
+ // addr(atom(A)) - addr(atom(B)) == 0.
+ const MCSymbolData *A_Base = 0, *B_Base = 0;
+
+ // Modified symbol references cannot be resolved.
+ if (A->getKind() != MCSymbolRefExpr::VK_None ||
+ B->getKind() != MCSymbolRefExpr::VK_None)
+ return false;
+
+ A_Base = Asm.getAtom(&Asm.getSymbolData(A->getSymbol()));
+ if (!A_Base)
+ return false;
+
+ B_Base = Asm.getAtom(&Asm.getSymbolData(B->getSymbol()));
+ if (!B_Base)
+ return false;
+
+ // If the atoms are the same, they are guaranteed to have the same address.
+ if (A_Base == B_Base)
+ return true;
+
+ // Otherwise, we can't prove this is fully resolved.
+ return false;
+ }
+
+ bool IsFixupFullyResolved(const MCAssembler &Asm,
+ const MCValue Target,
+ bool IsPCRel,
+ const MCFragment *DF) const {
+ // Otherwise, determine whether this value is actually resolved; scattering
+ // may cause atoms to move.
+
+ // Check if we are using the "simple" resolution algorithm (e.g.,
+ // i386).
+ if (!Asm.getBackend().hasReliableSymbolDifference()) {
+ const MCSection *BaseSection = 0;
+ if (IsPCRel)
+ BaseSection = &DF->getParent()->getSection();
+
+ return isScatteredFixupFullyResolvedSimple(Asm, Target, BaseSection);
+ }
+
+ // Otherwise, compute the proper answer as reliably as possible.
+
+ // If this is a PCrel relocation, find the base atom (identified by its
+ // symbol) that the fixup value is relative to.
+ const MCSymbolData *BaseSymbol = 0;
+ if (IsPCRel) {
+ BaseSymbol = DF->getAtom();
+ if (!BaseSymbol)
+ return false;
+ }
+
+ return isScatteredFixupFullyResolved(Asm, Target, BaseSymbol);
+ }
+
+ void WriteObject(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;
+ uint64_t LoadCommandsSize = is64Bit() ?
+ macho::SegmentLoadCommand64Size + NumSections * macho::Section64Size :
+ macho::SegmentLoadCommand32Size + NumSections * macho::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;
+ LoadCommandsSize += (macho::SymtabLoadCommandSize +
+ macho::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 SectionDataStart = (is64Bit() ? macho::Header64Size :
+ macho::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 Address = getSectionAddress(&SD);
+ uint64_t Size = Layout.getSectionAddressSize(&SD);
uint64_t FileSize = Layout.getSectionFileSize(&SD);
+ FileSize += getPaddingSize(&SD, Layout);
VMSize = std::max(VMSize, Address + Size);
- if (Asm.getBackend().isVirtualSection(SD.getSection()))
+ if (SD.getSection().isVirtualSection())
continue;
SectionDataSize = std::max(SectionDataSize, Address + Size);
uint64_t RelocTableEnd = SectionDataStart + SectionDataFileSize;
for (MCAssembler::const_iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
- std::vector<MachRelocationEntry> &Relocs = Relocations[it];
+ std::vector<macho::RelocationEntry> &Relocs = Relocations[it];
unsigned NumRelocs = Relocs.size();
- uint64_t SectionStart = SectionDataStart + Layout.getSectionAddress(it);
+ uint64_t SectionStart = SectionDataStart + getSectionAddress(it);
WriteSection(Asm, Layout, *it, SectionStart, RelocTableEnd, NumRelocs);
- RelocTableEnd += NumRelocs * RelocationInfoSize;
+ RelocTableEnd += NumRelocs * macho::RelocationInfoSize;
}
// Write the symbol table load command, if used.
// The string table is written after symbol table.
uint64_t StringTableOffset =
- SymbolTableOffset + NumSymTabSymbols * (Is64Bit ? Nlist64Size :
- Nlist32Size);
+ SymbolTableOffset + NumSymTabSymbols * (is64Bit() ? macho::Nlist64Size :
+ macho::Nlist32Size);
WriteSymtabLoadCommand(SymbolTableOffset, NumSymTabSymbols,
StringTableOffset, StringTable.size());
// Write the actual section data.
for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it)
- Asm.WriteSectionData(it, Layout, Writer);
+ ie = Asm.end(); it != ie; ++it) {
+ Asm.WriteSectionData(it, Layout);
+
+ uint64_t Pad = getPaddingSize(it, Layout);
+ for (unsigned int i = 0; i < Pad; ++i)
+ Write8(0);
+ }
// Write the extra padding.
WriteZeros(SectionDataPadding);
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];
+ std::vector<macho::RelocationEntry> &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);
// 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;
+ uint32_t Flags = macho::ISF_Local;
if (it->Symbol->isAbsolute())
- Flags |= ISF_Absolute;
+ Flags |= macho::ISF_Absolute;
Write32(Flags);
continue;
}
}
-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);
+MCObjectWriter *llvm::createMachObjectWriter(MCMachObjectTargetWriter *MOTW,
+ raw_ostream &OS,
+ bool IsLittleEndian) {
+ return new MachObjectWriter(MOTW, OS, IsLittleEndian);
}
projects / oota-llvm.git / blobdiff