#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Object/MachOFormat.h"
#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Target/TargetAsmBackend.h"
-
-// FIXME: Gross.
-#include "../Target/ARM/ARMFixupKinds.h"
-#include "../Target/X86/X86FixupKinds.h"
#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 FK_PCRel_1:
- case FK_Data_1: return 0;
- case FK_PCRel_2:
- case FK_Data_2: return 1;
- case FK_PCRel_4:
- // FIXME: Remove these!!!
- 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 doesSymbolRequireExternRelocation(MCSymbolData *SD) {
+bool MachObjectWriter::
+doesSymbolRequireExternRelocation(const MCSymbolData *SD) {
// Undefined symbols are always extern.
if (SD->Symbol->isUndefined())
return true;
return false;
}
-namespace {
-
-class MachObjectWriter : public MCObjectWriter {
- /// 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();
- }
- };
-
- /// The target specific Mach-O writer instance.
- llvm::OwningPtr<MCMachObjectTargetWriter> TargetObjectWriter;
-
- /// @name Relocation Data
- /// @{
-
- llvm::DenseMap<const MCSectionData*,
- std::vector<macho::RelocationEntry> > 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;
-
- /// @}
-
-private:
- /// @name Utility Methods
- /// @{
-
- bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
- const MCFixupKindInfo &FKI = Asm.getBackend().getFixupKindInfo(
- (MCFixupKind) Kind);
-
- 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;
-
- 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;
-public:
- MachObjectWriter(MCMachObjectTargetWriter *MOTW, raw_ostream &_OS,
- bool _IsLittleEndian)
- : MCObjectWriter(_OS, _IsLittleEndian), TargetObjectWriter(MOTW) {
- }
-
- /// @name Target Writer Proxy Accessors
- /// @{
+bool MachObjectWriter::
+MachSymbolData::operator<(const MachSymbolData &RHS) const {
+ return SymbolData->getSymbol().getName() <
+ RHS.SymbolData->getSymbol().getName();
+}
- bool is64Bit() const { return TargetObjectWriter->is64Bit(); }
- bool isARM() const {
- uint32_t CPUType = TargetObjectWriter->getCPUType() & ~mach::CTFM_ArchMask;
- return CPUType == mach::CTM_ARM;
- }
+bool MachObjectWriter::isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
+ const MCFixupKindInfo &FKI = Asm.getBackend().getFixupKindInfo(
+ (MCFixupKind) Kind);
- /// @}
-
- void WriteHeader(unsigned NumLoadCommands, unsigned LoadCommandsSize,
- bool SubsectionsViaSymbols);
-
- /// 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);
-
- void WriteSection(const MCAssembler &Asm, const MCAsmLayout &Layout,
- const MCSectionData &SD, uint64_t FileOffset,
- uint64_t RelocationsStart, unsigned NumRelocations);
-
- void WriteSymtabLoadCommand(uint32_t SymbolOffset, uint32_t NumSymbols,
- uint32_t StringTableOffset,
- uint32_t StringTableSize);
-
- 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);
-
- void WriteNlist(MachSymbolData &MSD, const MCAsmLayout &Layout);
-
- // 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.
+ return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel;
+}
- 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);
-
- void RecordScatteredRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup, MCValue Target,
- unsigned Log2Size,
- uint64_t &FixedValue);
-
- void RecordARMScatteredRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup, MCValue Target,
- unsigned Log2Size,
- uint64_t &FixedValue);
-
- void RecordARMMovwMovtRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup, MCValue Target,
- uint64_t &FixedValue);
-
- void RecordTLVPRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup, MCValue Target,
- uint64_t &FixedValue);
-
- static bool getARMFixupKindMachOInfo(unsigned Kind, unsigned &RelocType,
- unsigned &Log2Size);
-
- void RecordARMRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
- const MCFragment *Fragment, const MCFixup &Fixup,
- MCValue Target, uint64_t &FixedValue);
-
- void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
- const MCFragment *Fragment, const MCFixup &Fixup,
- MCValue Target, uint64_t &FixedValue);
-
- void BindIndirectSymbols(MCAssembler &Asm);
-
- /// 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);
-
- void computeSectionAddresses(const MCAssembler &Asm,
- const MCAsmLayout &Layout);
-
- void ExecutePostLayoutBinding(MCAssembler &Asm, const MCAsmLayout &Layout);
-
- virtual bool IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
- const MCSymbolData &DataA,
- const MCFragment &FB,
- bool InSet,
- bool IsPCRel) const;
-
- void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
-};
-
-} // end anonymous namespace
+uint64_t MachObjectWriter::getFragmentAddress(const MCFragment *Fragment,
+ const MCAsmLayout &Layout) const {
+ return getSectionAddress(Fragment->getParent()) +
+ Layout.getFragmentOffset(Fragment);
+}
uint64_t MachObjectWriter::getSymbolAddress(const MCSymbolData* SD,
const MCAsmLayout &Layout) const {
const MCSymbol &Symbol = Data.getSymbol();
uint8_t Type = 0;
uint16_t Flags = Data.getFlags();
- uint32_t Address = 0;
+ uint64_t Address = 0;
// Set the N_TYPE bits. See <mach-o/nlist.h>.
//
Write32(Address);
}
-void MachObjectWriter::RecordX86_64Relocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- uint64_t &FixedValue) {
- unsigned IsPCRel = isFixupKindPCRel(Asm, 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 =
- getFragmentAddress(Fragment, Layout) + 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 accommodated 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 = macho::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 = 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(&A_SD);
-
- const MCSymbol *B = &Target.getSymB()->getSymbol();
- MCSymbolData &B_SD = Asm.getSymbolData(*B);
- const MCSymbolData *B_Base = Asm.getAtom(&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");
-
- // 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. 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 += 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();
- IsExtern = 1;
- }
- else {
- Index = A_SD.getFragment()->getParent()->getOrdinal() + 1;
- IsExtern = 0;
- }
- Type = macho::RIT_X86_64_Unsigned;
-
- macho::RelocationEntry MRE;
- MRE.Word0 = FixupOffset;
- MRE.Word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (IsExtern << 27) |
- (Type << 28));
- Relocations[Fragment->getParent()].push_back(MRE);
-
- 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(&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 preceding
- // non-local symbol).
- if (Base) {
- Index = Base->getIndex();
- IsExtern = 1;
-
- // Add the local offset, if needed.
- if (Base != &SD)
- Value += Layout.getSymbolOffset(&SD) - Layout.getSymbolOffset(Base);
- } else if (Symbol->isInSection() && !Symbol->isVariable()) {
- // The index is the section ordinal (1-based).
- Index = SD.getFragment()->getParent()->getOrdinal() + 1;
- IsExtern = 0;
- 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() + "'");
- }
-
- 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 = macho::RIT_X86_64_GOTLoad;
- else
- Type = macho::RIT_X86_64_GOT;
- } else if (Modifier == MCSymbolRefExpr::VK_TLVP) {
- Type = macho::RIT_X86_64_TLV;
- } else if (Modifier != MCSymbolRefExpr::VK_None) {
- report_fatal_error("unsupported symbol modifier in relocation");
- } else {
- 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
- // 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 = 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 {
- if (Modifier != MCSymbolRefExpr::VK_None)
- report_fatal_error("unsupported symbol modifier in branch "
- "relocation");
-
- Type = macho::RIT_X86_64_Branch;
- }
- } else {
- if (Modifier == MCSymbolRefExpr::VK_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 = 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 = macho::RIT_X86_64_Unsigned;
- }
- }
-
- // x86_64 always writes custom values into the fixups.
- FixedValue = Value;
-
- // struct relocation_info (8 bytes)
- macho::RelocationEntry MRE;
- MRE.Word0 = FixupOffset;
- MRE.Word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (IsExtern << 27) |
- (Type << 28));
- Relocations[Fragment->getParent()].push_back(MRE);
-}
-
-void MachObjectWriter::RecordScatteredRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- unsigned Log2Size,
- uint64_t &FixedValue) {
- uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
- unsigned IsPCRel = isFixupKindPCRel(Asm, Fixup.getKind());
- unsigned Type = macho::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 = getSymbolAddress(A_SD, Layout);
- uint64_t SecAddr = getSectionAddress(A_SD->getFragment()->getParent());
- FixedValue += SecAddr;
- 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() ? (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 == macho::RIT_Difference ||
- Type == macho::RIT_Generic_LocalDifference) {
- macho::RelocationEntry MRE;
- MRE.Word0 = ((0 << 0) |
- (macho::RIT_Pair << 24) |
- (Log2Size << 28) |
- (IsPCRel << 30) |
- macho::RF_Scattered);
- MRE.Word1 = Value2;
- Relocations[Fragment->getParent()].push_back(MRE);
- }
-
- macho::RelocationEntry MRE;
- MRE.Word0 = ((FixupOffset << 0) |
- (Type << 24) |
- (Log2Size << 28) |
- (IsPCRel << 30) |
- macho::RF_Scattered);
- MRE.Word1 = Value;
- Relocations[Fragment->getParent()].push_back(MRE);
-}
-
-void MachObjectWriter::RecordARMScatteredRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- unsigned Log2Size,
- uint64_t &FixedValue) {
- uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
- unsigned IsPCRel = isFixupKindPCRel(Asm, Fixup.getKind());
- unsigned Type = macho::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 = getSymbolAddress(A_SD, Layout);
- uint64_t SecAddr = getSectionAddress(A_SD->getFragment()->getParent());
- FixedValue += SecAddr;
- 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.
- Type = macho::RIT_Difference;
- 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 == macho::RIT_Difference ||
- Type == macho::RIT_Generic_LocalDifference) {
- macho::RelocationEntry MRE;
- MRE.Word0 = ((0 << 0) |
- (macho::RIT_Pair << 24) |
- (Log2Size << 28) |
- (IsPCRel << 30) |
- macho::RF_Scattered);
- MRE.Word1 = Value2;
- Relocations[Fragment->getParent()].push_back(MRE);
- }
-
- macho::RelocationEntry MRE;
- MRE.Word0 = ((FixupOffset << 0) |
- (Type << 24) |
- (Log2Size << 28) |
- (IsPCRel << 30) |
- macho::RF_Scattered);
- MRE.Word1 = Value;
- Relocations[Fragment->getParent()].push_back(MRE);
-}
-
-void MachObjectWriter::RecordARMMovwMovtRelocation(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(Asm, Fixup.getKind());
- unsigned Type = macho::RIT_ARM_Half;
-
- // 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 = getSymbolAddress(A_SD, Layout);
- uint32_t Value2 = 0;
- uint64_t SecAddr = getSectionAddress(A_SD->getFragment()->getParent());
- FixedValue += SecAddr;
-
- 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.
- Type = macho::RIT_ARM_HalfDifference;
- Value2 = getSymbolAddress(B_SD, Layout);
- FixedValue -= getSectionAddress(B_SD->getFragment()->getParent());
- }
-
- // Relocations are written out in reverse order, so the PAIR comes first.
- // ARM_RELOC_HALF and ARM_RELOC_HALF_SECTDIFF abuse the r_length field:
- //
- // For these two r_type relocations they always have a pair following them and
- // the r_length bits are used differently. The encoding of the r_length is as
- // follows:
- // low bit of r_length:
- // 0 - :lower16: for movw instructions
- // 1 - :upper16: for movt instructions
- // high bit of r_length:
- // 0 - arm instructions
- // 1 - thumb instructions
- // the other half of the relocated expression is in the following pair
- // relocation entry in the the low 16 bits of r_address field.
- unsigned ThumbBit = 0;
- unsigned MovtBit = 0;
- switch ((unsigned)Fixup.getKind()) {
- default: break;
- case ARM::fixup_arm_movt_hi16:
- case ARM::fixup_arm_movt_hi16_pcrel:
- MovtBit = 1;
- break;
- case ARM::fixup_t2_movt_hi16:
- case ARM::fixup_t2_movt_hi16_pcrel:
- MovtBit = 1;
- // Fallthrough
- case ARM::fixup_t2_movw_lo16:
- case ARM::fixup_t2_movw_lo16_pcrel:
- ThumbBit = 1;
- break;
- }
-
-
- if (Type == macho::RIT_ARM_HalfDifference) {
- uint32_t OtherHalf = MovtBit
- ? (FixedValue & 0xffff) : ((FixedValue & 0xffff0000) >> 16);
-
- macho::RelocationEntry MRE;
- MRE.Word0 = ((OtherHalf << 0) |
- (macho::RIT_Pair << 24) |
- (MovtBit << 28) |
- (ThumbBit << 29) |
- (IsPCRel << 30) |
- macho::RF_Scattered);
- MRE.Word1 = Value2;
- Relocations[Fragment->getParent()].push_back(MRE);
- }
-
- macho::RelocationEntry MRE;
- MRE.Word0 = ((FixupOffset << 0) |
- (Type << 24) |
- (MovtBit << 28) |
- (ThumbBit << 29) |
- (IsPCRel << 30) |
- macho::RF_Scattered);
- MRE.Word1 = Value;
- Relocations[Fragment->getParent()].push_back(MRE);
-}
-
-void MachObjectWriter::RecordTLVPRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- uint64_t &FixedValue) {
- assert(Target.getSymA()->getKind() == MCSymbolRefExpr::VK_TLVP &&
- !is64Bit() &&
- "Should only be called with a 32-bit TLVP relocation!");
-
- unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
- uint32_t Value = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
- unsigned IsPCRel = 0;
-
- // Get the symbol data.
- MCSymbolData *SD_A = &Asm.getSymbolData(Target.getSymA()->getSymbol());
- unsigned Index = SD_A->getIndex();
-
- // 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)
- macho::RelocationEntry MRE;
- MRE.Word0 = Value;
- MRE.Word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (1 << 27) | // Extern
- (macho::RIT_Generic_TLV << 28)); // Type
- Relocations[Fragment->getParent()].push_back(MRE);
-}
-
-bool MachObjectWriter::getARMFixupKindMachOInfo(unsigned Kind,
- unsigned &RelocType,
- unsigned &Log2Size) {
- RelocType = unsigned(macho::RIT_Vanilla);
- Log2Size = ~0U;
-
- switch (Kind) {
- default:
- return false;
-
- case FK_Data_1:
- Log2Size = llvm::Log2_32(1);
- return true;
- case FK_Data_2:
- Log2Size = llvm::Log2_32(2);
- return true;
- case FK_Data_4:
- Log2Size = llvm::Log2_32(4);
- return true;
- case FK_Data_8:
- Log2Size = llvm::Log2_32(8);
- return true;
-
- // Handle 24-bit branch kinds.
- case ARM::fixup_arm_ldst_pcrel_12:
- case ARM::fixup_arm_pcrel_10:
- case ARM::fixup_arm_adr_pcrel_12:
- case ARM::fixup_arm_condbranch:
- case ARM::fixup_arm_uncondbranch:
- RelocType = unsigned(macho::RIT_ARM_Branch24Bit);
- // Report as 'long', even though that is not quite accurate.
- Log2Size = llvm::Log2_32(4);
- return true;
-
- // Handle Thumb branches.
- case ARM::fixup_arm_thumb_br:
- RelocType = unsigned(macho::RIT_ARM_ThumbBranch22Bit);
- Log2Size = llvm::Log2_32(2);
- return true;
-
- case ARM::fixup_t2_uncondbranch:
- case ARM::fixup_arm_thumb_bl:
- case ARM::fixup_arm_thumb_blx:
- RelocType = unsigned(macho::RIT_ARM_ThumbBranch22Bit);
- Log2Size = llvm::Log2_32(4);
- return true;
-
- case ARM::fixup_arm_movt_hi16:
- case ARM::fixup_arm_movt_hi16_pcrel:
- case ARM::fixup_t2_movt_hi16:
- case ARM::fixup_t2_movt_hi16_pcrel:
- RelocType = unsigned(macho::RIT_ARM_HalfDifference);
- // Report as 'long', even though that is not quite accurate.
- Log2Size = llvm::Log2_32(4);
- return true;
-
- case ARM::fixup_arm_movw_lo16:
- case ARM::fixup_arm_movw_lo16_pcrel:
- case ARM::fixup_t2_movw_lo16:
- case ARM::fixup_t2_movw_lo16_pcrel:
- RelocType = unsigned(macho::RIT_ARM_Half);
- // Report as 'long', even though that is not quite accurate.
- Log2Size = llvm::Log2_32(4);
- return true;
- }
-}
-void MachObjectWriter::RecordARMRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- uint64_t &FixedValue) {
- unsigned IsPCRel = isFixupKindPCRel(Asm, Fixup.getKind());
- unsigned Log2Size;
- unsigned RelocType = macho::RIT_Vanilla;
- if (!getARMFixupKindMachOInfo(Fixup.getKind(), RelocType, Log2Size)) {
- report_fatal_error("unknown ARM fixup kind!");
- 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.
- if (Target.getSymB()) {
- if (RelocType == macho::RIT_ARM_Half ||
- RelocType == macho::RIT_ARM_HalfDifference)
- return RecordARMMovwMovtRelocation(Asm, Layout, Fragment, Fixup,
- Target, FixedValue);
- return RecordARMScatteredRelocation(Asm, Layout, Fragment, Fixup,
- Target, Log2Size, FixedValue);
- }
-
- // Get the symbol data, if any.
- MCSymbolData *SD = 0;
- if (Target.getSymA())
- SD = &Asm.getSymbolData(Target.getSymA()->getSymbol());
-
- // FIXME: For other platforms, we need to use scattered relocations for
- // internal relocations with offsets. If this is an internal relocation with
- // an offset, it also needs a scattered relocation entry.
- //
- // Is this right for ARM?
- uint32_t Offset = Target.getConstant();
- if (IsPCRel && RelocType == macho::RIT_Vanilla)
- Offset += 1 << Log2Size;
- if (Offset && SD && !doesSymbolRequireExternRelocation(SD))
- return RecordARMScatteredRelocation(Asm, Layout, Fragment, Fixup, Target,
- Log2Size, FixedValue);
-
- // See <reloc.h>.
- uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
- unsigned Index = 0;
- unsigned IsExtern = 0;
- unsigned Type = 0;
-
- if (Target.isAbsolute()) { // constant
- // FIXME!
- report_fatal_error("FIXME: relocations to absolute targets "
- "not yet implemented");
- } else {
- // Resolve constant variables.
- if (SD->getSymbol().isVariable()) {
- int64_t Res;
- if (SD->getSymbol().getVariableValue()->EvaluateAsAbsolute(
- Res, Layout, SectionAddress)) {
- FixedValue = Res;
- return;
- }
- }
-
- // 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.getSymbolOffset(SD);
- } else {
- // The index is the section ordinal (1-based).
- const MCSectionData &SymSD = Asm.getSectionData(
- SD->getSymbol().getSection());
- Index = SymSD.getOrdinal() + 1;
- FixedValue += getSectionAddress(&SymSD);
- }
- if (IsPCRel)
- FixedValue -= getSectionAddress(Fragment->getParent());
-
- // The type is determined by the fixup kind.
- Type = RelocType;
- }
-
- // struct relocation_info (8 bytes)
- macho::RelocationEntry MRE;
- MRE.Word0 = FixupOffset;
- MRE.Word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (IsExtern << 27) |
- (Type << 28));
- Relocations[Fragment->getParent()].push_back(MRE);
-}
-
void MachObjectWriter::RecordRelocation(const MCAssembler &Asm,
const MCAsmLayout &Layout,
const MCFragment *Fragment,
const MCFixup &Fixup,
MCValue Target,
uint64_t &FixedValue) {
- // 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(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() &&
- 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.
- if (Target.getSymB())
- return RecordScatteredRelocation(Asm, Layout, Fragment, Fixup,
- Target, Log2Size, 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, Log2Size, FixedValue);
-
- // See <reloc.h>.
- uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
- 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 = macho::RIT_Vanilla;
- } else {
- // Resolve constant variables.
- if (SD->getSymbol().isVariable()) {
- int64_t Res;
- if (SD->getSymbol().getVariableValue()->EvaluateAsAbsolute(
- Res, Layout, SectionAddress)) {
- FixedValue = Res;
- return;
- }
- }
-
- // 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.getSymbolOffset(SD);
- } else {
- // The index is the section ordinal (1-based).
- const MCSectionData &SymSD = Asm.getSectionData(
- SD->getSymbol().getSection());
- Index = SymSD.getOrdinal() + 1;
- FixedValue += getSectionAddress(&SymSD);
- }
- if (IsPCRel)
- FixedValue -= getSectionAddress(Fragment->getParent());
-
- Type = macho::RIT_Vanilla;
- }
-
- // struct relocation_info (8 bytes)
- macho::RelocationEntry MRE;
- MRE.Word0 = FixupOffset;
- MRE.Word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (IsExtern << 27) |
- (Type << 28));
- Relocations[Fragment->getParent()].push_back(MRE);
+ TargetObjectWriter->RecordRelocation(this, Asm, Layout, Fragment, Fixup,
+ Target, FixedValue);
}
void MachObjectWriter::BindIndirectSymbols(MCAssembler &Asm) {
// 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.
+ //
+ // If the file isn't using sub-sections-via-symbols, we can make the
+ // same assumptions about any symbol that we normally make about
+ // assembler locals.
if (!Asm.getBackend().hasReliableSymbolDifference()) {
- if (!SA.isTemporary() || !SA.isInSection() || &SecA != &SecB)
+ if (!SA.isInSection() || &SecA != &SecB ||
+ (!SA.isTemporary() && &FB != Asm.getSymbolData(SA).getFragment()))
return false;
return true;
}
+ // For Darwin x86_64, there is one special case when the reference IsPCRel.
+ // If the fragment with the reference does not have a base symbol but meets
+ // the simple way of dealing with this, in that it is a temporary symbol in
+ // the same atom then it is assumed to be fully resolved. This is needed so
+ // a relocation entry is not created and so the static linker does not
+ // mess up the reference later.
+ else if(!FB.getAtom() &&
+ SA.isTemporary() && SA.isInSection() && &SecA == &SecB){
+ return true;
+ }
} else {
if (!TargetObjectWriter->useAggressiveSymbolFolding())
return false;
}
- const MCFragment &FA = *Asm.getSymbolData(SA).getFragment();
+ const MCFragment *FA = Asm.getSymbolData(SA).getFragment();
+
+ // Bail if the symbol has no fragment.
+ if (!FA)
+ return false;
- A_Base = FA.getAtom();
+ A_Base = FA->getAtom();
if (!A_Base)
return false;
return false;
}
-void MachObjectWriter::WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) {
+void MachObjectWriter::WriteObject(MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
unsigned NumSections = Asm.size();
// The section data starts after the header, the segment load command (and
// Write the actual section data.
for (MCAssembler::const_iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
- Asm.WriteSectionData(it, Layout);
+ Asm.writeSectionData(it, Layout);
uint64_t Pad = getPaddingSize(it, Layout);
for (unsigned int i = 0; i < Pad; ++i)
projects / oota-llvm.git / blobdiff