//
//===----------------------------------------------------------------------===//
+#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"
}
}
-static bool isFixupKindPCRel(unsigned Kind) {
- switch (Kind) {
- default:
- return false;
- case FK_PCRel_1:
- case FK_PCRel_2:
- case FK_PCRel_4:
- 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())
}
};
+ /// The target specific Mach-O writer instance.
+ llvm::OwningPtr<MCMachObjectTargetWriter> TargetObjectWriter;
+
/// @name Relocation Data
/// @{
/// @}
- unsigned Is64Bit : 1;
+private:
+ /// @name Utility Methods
+ /// @{
+
+ bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
+ const MCFixupKindInfo &FKI = Asm.getBackend().getFixupKindInfo(
+ (MCFixupKind) Kind);
- uint32_t CPUType;
- uint32_t CPUSubtype;
+ 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:
- MachObjectWriter(raw_ostream &_OS,
- bool _Is64Bit, uint32_t _CPUType, uint32_t _CPUSubtype,
+ MachObjectWriter(MCMachObjectTargetWriter *MOTW, raw_ostream &_OS,
bool _IsLittleEndian)
- : MCObjectWriter(_OS, _IsLittleEndian),
- Is64Bit(_Is64Bit), CPUType(_CPUType), CPUSubtype(_CPUSubtype) {
+ : MCObjectWriter(_OS, _IsLittleEndian), TargetObjectWriter(MOTW) {
}
+ /// @name Target Writer Proxy Accessors
+ /// @{
+
+ bool is64Bit() const { return TargetObjectWriter->is64Bit(); }
+
+ /// @}
+
void WriteHeader(unsigned NumLoadCommands, unsigned LoadCommandsSize,
bool SubsectionsViaSymbols) {
uint32_t Flags = 0;
uint64_t Start = OS.tell();
(void) Start;
- Write32(Is64Bit ? macho::HM_Object64 : macho::HM_Object32);
+ Write32(is64Bit() ? macho::HM_Object64 : macho::HM_Object32);
- Write32(CPUType);
- Write32(CPUSubtype);
+ 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 ?
+ assert(OS.tell() - Start == is64Bit() ?
macho::Header64Size : macho::Header32Size);
}
uint64_t Start = OS.tell();
(void) Start;
- unsigned SegmentLoadCommandSize = Is64Bit ? macho::SegmentLoadCommand64Size:
+ unsigned SegmentLoadCommandSize =
+ is64Bit() ? macho::SegmentLoadCommand64Size:
macho::SegmentLoadCommand32Size;
- Write32(Is64Bit ? macho::LCT_Segment64 : macho::LCT_Segment);
+ Write32(is64Bit() ? macho::LCT_Segment64 : macho::LCT_Segment);
Write32(SegmentLoadCommandSize +
- NumSections * (Is64Bit ? macho::Section64Size :
+ 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 (SD.getSection().isVirtualSection()) {
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 ? macho::Section64Size :
+ assert(OS.tell() - Start == is64Bit() ? macho::Section64Size :
macho::Section32Size);
}
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 (A_Base == B_Base && A_Base)
report_fatal_error("unsupported relocation with identical base");
- Value += Layout.getSymbolAddress(&A_SD) -
- (A_Base == NULL ? 0 : Layout.getSymbolAddress(A_Base));
- Value -= Layout.getSymbolAddress(&B_SD) -
- (B_Base == NULL ? 0 : 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));
if (A_Base) {
Index = A_Base->getIndex();
// 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() + "'");
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 = macho::RIT_Vanilla;
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()) {
// for pedantic compatibility with 'as'.
Type = A_SD->isExternal() ? macho::RIT_Difference :
macho::RIT_LocalDifference;
- Value2 = Layout.getSymbolAddress(B_SD);
+ Value2 = getSymbolAddress(B_SD, Layout);
+ FixedValue -= getSectionAddress(B_SD->getFragment()->getParent());
}
// Relocations are written out in reverse order, so the PAIR comes first.
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!");
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
if (Target.getSymB()) {
// If this is a subtraction then we're pcrel.
uint32_t FixupAddress =
- Layout.getFragmentAddress(Fragment) + Fixup.getOffset();
+ getFragmentAddress(Fragment, Layout) + Fixup.getOffset();
MCSymbolData *SD_B = &Asm.getSymbolData(Target.getSymB()->getSymbol());
IsPCRel = 1;
- FixedValue = (FixupAddress - Layout.getSymbolAddress(SD_B) +
+ FixedValue = (FixupAddress - getSymbolAddress(SD_B, Layout) +
Target.getConstant());
FixedValue += 1ULL << Log2Size;
} else {
void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment *Fragment, const MCFixup &Fixup,
MCValue Target, uint64_t &FixedValue) {
- if (Is64Bit) {
+ 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.
// FIXME: Currently, these are never generated (see code below). I cannot
// find a case where they are actually emitted.
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);
+ FixedValue -= Layout.getSymbolOffset(SD);
} else {
// The index is the section ordinal (1-based).
Index = SD->getFragment()->getParent()->getOrdinal() + 1;
+ FixedValue += getSectionAddress(SD->getFragment()->getParent());
}
+ if (IsPCRel)
+ FixedValue -= getSectionAddress(Fragment->getParent());
Type = macho::RIT_Vanilla;
}
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);
}
+ 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 {
- // If we aren't using scattered symbols, the fixup is fully resolved.
- if (!Asm.getBackend().hasScatteredSymbols())
- return true;
-
// Otherwise, determine whether this value is actually resolved; scattering
// may cause atoms to move.
// 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 ?
+ uint64_t LoadCommandsSize = is64Bit() ?
macho::SegmentLoadCommand64Size + NumSections * macho::Section64Size :
macho::SegmentLoadCommand32Size + NumSections * macho::Section32Size;
// Compute the total size of the section data, as well as its file size and
// vm size.
- uint64_t SectionDataStart = (Is64Bit ? macho::Header64Size :
+ uint64_t SectionDataStart = (is64Bit() ? macho::Header64Size :
macho::Header32Size) + LoadCommandsSize;
uint64_t SectionDataSize = 0;
uint64_t SectionDataFileSize = 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);
ie = Asm.end(); it != ie; ++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 * macho::RelocationInfoSize;
}
// The string table is written after symbol table.
uint64_t StringTableOffset =
- SymbolTableOffset + NumSymTabSymbols * (Is64Bit ? macho::Nlist64Size :
+ 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, this);
+ 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);
}
-MCObjectWriter *llvm::createMachObjectWriter(raw_ostream &OS, bool is64Bit,
- uint32_t CPUType,
- uint32_t CPUSubtype,
+MCObjectWriter *llvm::createMachObjectWriter(MCMachObjectTargetWriter *MOTW,
+ raw_ostream &OS,
bool IsLittleEndian) {
- return new MachObjectWriter(OS, is64Bit, CPUType, CPUSubtype, IsLittleEndian);
+ return new MachObjectWriter(MOTW, OS, IsLittleEndian);
}