//
//===----------------------------------------------------------------------===//
+#include "MCTargetDesc/ARMMCTargetDesc.h"
#include "MCTargetDesc/ARMBaseInfo.h"
#include "MCTargetDesc/ARMFixupKinds.h"
#include "llvm/ADT/Twine.h"
-#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCAsmLayout.h"
-#include "llvm/MC/MCMachObjectWriter.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCFixupKindInfo.h"
+#include "llvm/MC/MCMachOSymbolFlags.h"
+#include "llvm/MC/MCMachObjectWriter.h"
#include "llvm/MC/MCValue.h"
-#include "llvm/Object/MachOFormat.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MachO.h"
using namespace llvm;
-using namespace llvm::object;
namespace {
class ARMMachObjectWriter : public MCMachObjectTargetWriter {
MCValue Target,
unsigned Log2Size,
uint64_t &FixedValue);
- void RecordARMMovwMovtRelocation(MachObjectWriter *Writer,
- const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup, MCValue Target,
- uint64_t &FixedValue);
+ void RecordARMScatteredHalfRelocation(MachObjectWriter *Writer,
+ const MCAssembler &Asm,
+ const MCAsmLayout &Layout,
+ const MCFragment *Fragment,
+ const MCFixup &Fixup, MCValue Target,
+ uint64_t &FixedValue);
+
+ bool requiresExternRelocation(MachObjectWriter *Writer,
+ const MCAssembler &Asm,
+ const MCFragment &Fragment,
+ unsigned RelocType, const MCSymbolData *SD,
+ uint64_t FixedValue);
public:
ARMMachObjectWriter(bool Is64Bit, uint32_t CPUType,
void RecordRelocation(MachObjectWriter *Writer,
const MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment *Fragment, const MCFixup &Fixup,
- MCValue Target, uint64_t &FixedValue);
+ MCValue Target, uint64_t &FixedValue) override;
};
}
static bool getARMFixupKindMachOInfo(unsigned Kind, unsigned &RelocType,
unsigned &Log2Size) {
- RelocType = unsigned(macho::RIT_Vanilla);
+ RelocType = unsigned(MachO::ARM_RELOC_VANILLA);
Log2Size = ~0U;
switch (Kind) {
Log2Size = llvm::Log2_32(8);
return true;
- // Handle 24-bit branch kinds.
+ // These fixups are expected to always be resolvable at assembly time and
+ // have no relocations supported.
case ARM::fixup_arm_ldst_pcrel_12:
case ARM::fixup_arm_pcrel_10:
case ARM::fixup_arm_adr_pcrel_12:
+ return false;
+
+ // Handle 24-bit branch kinds.
case ARM::fixup_arm_condbranch:
case ARM::fixup_arm_uncondbranch:
- RelocType = unsigned(macho::RIT_ARM_Branch24Bit);
+ case ARM::fixup_arm_uncondbl:
+ case ARM::fixup_arm_condbl:
+ case ARM::fixup_arm_blx:
+ RelocType = unsigned(MachO::ARM_RELOC_BR24);
// 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);
+ RelocType = unsigned(MachO::ARM_THUMB_RELOC_BR22);
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);
+ RelocType = unsigned(MachO::ARM_THUMB_RELOC_BR22);
Log2Size = llvm::Log2_32(4);
return true;
+ // For movw/movt 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
case ARM::fixup_arm_movt_hi16:
- case ARM::fixup_arm_movt_hi16_pcrel:
+ RelocType = unsigned(MachO::ARM_RELOC_HALF);
+ Log2Size = 1;
+ return true;
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);
+ RelocType = unsigned(MachO::ARM_RELOC_HALF);
+ Log2Size = 3;
return true;
case ARM::fixup_arm_movw_lo16:
- case ARM::fixup_arm_movw_lo16_pcrel:
+ RelocType = unsigned(MachO::ARM_RELOC_HALF);
+ Log2Size = 0;
+ return true;
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);
+ RelocType = unsigned(MachO::ARM_RELOC_HALF);
+ Log2Size = 2;
return true;
}
}
void ARMMachObjectWriter::
-RecordARMMovwMovtRelocation(MachObjectWriter *Writer,
- const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- uint64_t &FixedValue) {
+RecordARMScatteredHalfRelocation(MachObjectWriter *Writer,
+ 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 = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
- unsigned Type = macho::RIT_ARM_Half;
+ unsigned Type = MachO::ARM_RELOC_HALF;
// See <reloc.h>.
const MCSymbol *A = &Target.getSymA()->getSymbol();
- MCSymbolData *A_SD = &Asm.getSymbolData(*A);
+ const MCSymbolData *A_SD = &Asm.getSymbolData(*A);
if (!A_SD->getFragment())
- report_fatal_error("symbol '" + A->getName() +
+ Asm.getContext().FatalError(Fixup.getLoc(),
+ "symbol '" + A->getName() +
"' can not be undefined in a subtraction expression");
uint32_t Value = Writer->getSymbolAddress(A_SD, Layout);
FixedValue += SecAddr;
if (const MCSymbolRefExpr *B = Target.getSymB()) {
- MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
+ const MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
if (!B_SD->getFragment())
- report_fatal_error("symbol '" + B->getSymbol().getName() +
+ Asm.getContext().FatalError(Fixup.getLoc(),
+ "symbol '" + B->getSymbol().getName() +
"' can not be undefined in a subtraction expression");
// Select the appropriate difference relocation type.
- Type = macho::RIT_ARM_HalfDifference;
+ Type = MachO::ARM_RELOC_HALF_SECTDIFF;
Value2 = Writer->getSymbolAddress(B_SD, Layout);
FixedValue -= Writer->getSectionAddress(B_SD->getFragment()->getParent());
}
// 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.
+ // relocation entry in 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;
+ // The thumb bit shouldn't be set in the 'other-half' bit of the
+ // relocation, but it will be set in FixedValue if the base symbol
+ // is a thumb function. Clear it out here.
+ if (A_SD->getFlags() & SF_ThumbFunc)
+ FixedValue &= 0xfffffffe;
break;
case ARM::fixup_t2_movt_hi16:
- case ARM::fixup_t2_movt_hi16_pcrel:
+ if (A_SD->getFlags() & SF_ThumbFunc)
+ FixedValue &= 0xfffffffe;
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) {
+ if (Type == MachO::ARM_RELOC_HALF_SECTDIFF) {
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;
+ MachO::any_relocation_info MRE;
+ MRE.r_word0 = ((OtherHalf << 0) |
+ (MachO::ARM_RELOC_PAIR << 24) |
+ (MovtBit << 28) |
+ (ThumbBit << 29) |
+ (IsPCRel << 30) |
+ MachO::R_SCATTERED);
+ MRE.r_word1 = Value2;
Writer->addRelocation(Fragment->getParent(), MRE);
}
- macho::RelocationEntry MRE;
- MRE.Word0 = ((FixupOffset << 0) |
- (Type << 24) |
- (MovtBit << 28) |
- (ThumbBit << 29) |
- (IsPCRel << 30) |
- macho::RF_Scattered);
- MRE.Word1 = Value;
+ MachO::any_relocation_info MRE;
+ MRE.r_word0 = ((FixupOffset << 0) |
+ (Type << 24) |
+ (MovtBit << 28) |
+ (ThumbBit << 29) |
+ (IsPCRel << 30) |
+ MachO::R_SCATTERED);
+ MRE.r_word1 = Value;
Writer->addRelocation(Fragment->getParent(), MRE);
}
uint64_t &FixedValue) {
uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
- unsigned Type = macho::RIT_Vanilla;
+ unsigned Type = MachO::ARM_RELOC_VANILLA;
// See <reloc.h>.
const MCSymbol *A = &Target.getSymA()->getSymbol();
- MCSymbolData *A_SD = &Asm.getSymbolData(*A);
+ const MCSymbolData *A_SD = &Asm.getSymbolData(*A);
if (!A_SD->getFragment())
- report_fatal_error("symbol '" + A->getName() +
+ Asm.getContext().FatalError(Fixup.getLoc(),
+ "symbol '" + A->getName() +
"' can not be undefined in a subtraction expression");
uint32_t Value = Writer->getSymbolAddress(A_SD, Layout);
uint32_t Value2 = 0;
if (const MCSymbolRefExpr *B = Target.getSymB()) {
- MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
+ const MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
if (!B_SD->getFragment())
- report_fatal_error("symbol '" + B->getSymbol().getName() +
+ Asm.getContext().FatalError(Fixup.getLoc(),
+ "symbol '" + B->getSymbol().getName() +
"' can not be undefined in a subtraction expression");
// Select the appropriate difference relocation type.
- Type = macho::RIT_Difference;
+ Type = MachO::ARM_RELOC_SECTDIFF;
Value2 = Writer->getSymbolAddress(B_SD, Layout);
FixedValue -= Writer->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;
+ if (Type == MachO::ARM_RELOC_SECTDIFF ||
+ Type == MachO::ARM_RELOC_LOCAL_SECTDIFF) {
+ MachO::any_relocation_info MRE;
+ MRE.r_word0 = ((0 << 0) |
+ (MachO::ARM_RELOC_PAIR << 24) |
+ (Log2Size << 28) |
+ (IsPCRel << 30) |
+ MachO::R_SCATTERED);
+ MRE.r_word1 = Value2;
Writer->addRelocation(Fragment->getParent(), MRE);
}
- macho::RelocationEntry MRE;
- MRE.Word0 = ((FixupOffset << 0) |
- (Type << 24) |
- (Log2Size << 28) |
- (IsPCRel << 30) |
- macho::RF_Scattered);
- MRE.Word1 = Value;
+ MachO::any_relocation_info MRE;
+ MRE.r_word0 = ((FixupOffset << 0) |
+ (Type << 24) |
+ (Log2Size << 28) |
+ (IsPCRel << 30) |
+ MachO::R_SCATTERED);
+ MRE.r_word1 = Value;
Writer->addRelocation(Fragment->getParent(), MRE);
}
+bool ARMMachObjectWriter::requiresExternRelocation(MachObjectWriter *Writer,
+ const MCAssembler &Asm,
+ const MCFragment &Fragment,
+ unsigned RelocType,
+ const MCSymbolData *SD,
+ uint64_t FixedValue) {
+ // Most cases can be identified purely from the symbol.
+ if (Writer->doesSymbolRequireExternRelocation(SD))
+ return true;
+ int64_t Value = (int64_t)FixedValue; // The displacement is signed.
+ int64_t Range;
+ switch (RelocType) {
+ default:
+ return false;
+ case MachO::ARM_RELOC_BR24:
+ // PC pre-adjustment of 8 for these instructions.
+ Value -= 8;
+ // ARM BL/BLX has a 25-bit offset.
+ Range = 0x1ffffff;
+ break;
+ case MachO::ARM_THUMB_RELOC_BR22:
+ // PC pre-adjustment of 4 for these instructions.
+ Value -= 4;
+ // Thumb BL/BLX has a 24-bit offset.
+ Range = 0xffffff;
+ }
+ // BL/BLX also use external relocations when an internal relocation
+ // would result in the target being out of range. This gives the linker
+ // enough information to generate a branch island.
+ const MCSectionData &SymSD = Asm.getSectionData(
+ SD->getSymbol().getSection());
+ Value += Writer->getSectionAddress(&SymSD);
+ Value -= Writer->getSectionAddress(Fragment.getParent());
+ // If the resultant value would be out of range for an internal relocation,
+ // use an external instead.
+ if (Value > Range || Value < -(Range + 1))
+ return true;
+ return false;
+}
+
void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer,
const MCAssembler &Asm,
const MCAsmLayout &Layout,
uint64_t &FixedValue) {
unsigned IsPCRel = Writer->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;
- }
+ unsigned RelocType = MachO::ARM_RELOC_VANILLA;
+ if (!getARMFixupKindMachOInfo(Fixup.getKind(), RelocType, Log2Size))
+ // If we failed to get fixup kind info, it's because there's no legal
+ // relocation type for the fixup kind. This happens when it's a fixup that's
+ // expected to always be resolvable at assembly time and not have any
+ // relocations needed.
+ Asm.getContext().FatalError(Fixup.getLoc(),
+ "unsupported relocation on symbol");
// 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(Writer, Asm, Layout, Fragment, Fixup,
- Target, FixedValue);
+ if (RelocType == MachO::ARM_RELOC_HALF)
+ return RecordARMScatteredHalfRelocation(Writer, Asm, Layout, Fragment,
+ Fixup, Target, FixedValue);
return RecordARMScatteredRelocation(Writer, Asm, Layout, Fragment, Fixup,
Target, Log2Size, FixedValue);
}
// Get the symbol data, if any.
- MCSymbolData *SD = 0;
+ const MCSymbolData *SD = nullptr;
if (Target.getSymA())
SD = &Asm.getSymbolData(Target.getSymA()->getSymbol());
//
// Is this right for ARM?
uint32_t Offset = Target.getConstant();
- if (IsPCRel && RelocType == macho::RIT_Vanilla)
+ if (IsPCRel && RelocType == MachO::ARM_RELOC_VANILLA)
Offset += 1 << Log2Size;
if (Offset && SD && !Writer->doesSymbolRequireExternRelocation(SD))
return RecordARMScatteredRelocation(Writer, Asm, Layout, Fragment, Fixup,
}
// Check whether we need an external or internal relocation.
- if (Writer->doesSymbolRequireExternRelocation(SD)) {
+ if (requiresExternRelocation(Writer, Asm, *Fragment, RelocType, SD,
+ FixedValue)) {
IsExtern = 1;
Index = SD->getIndex();
}
// struct relocation_info (8 bytes)
- macho::RelocationEntry MRE;
- MRE.Word0 = FixupOffset;
- MRE.Word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (IsExtern << 27) |
- (Type << 28));
+ MachO::any_relocation_info MRE;
+ MRE.r_word0 = FixupOffset;
+ MRE.r_word1 = ((Index << 0) |
+ (IsPCRel << 24) |
+ (Log2Size << 25) |
+ (IsExtern << 27) |
+ (Type << 28));
+
+ // Even when it's not a scattered relocation, movw/movt always uses
+ // a PAIR relocation.
+ if (Type == MachO::ARM_RELOC_HALF) {
+ // The other-half value only gets populated for the movt and movw
+ // relocation entries.
+ uint32_t Value = 0;
+ switch ((unsigned)Fixup.getKind()) {
+ default: break;
+ case ARM::fixup_arm_movw_lo16:
+ case ARM::fixup_t2_movw_lo16:
+ Value = (FixedValue >> 16) & 0xffff;
+ break;
+ case ARM::fixup_arm_movt_hi16:
+ case ARM::fixup_t2_movt_hi16:
+ Value = FixedValue & 0xffff;
+ break;
+ }
+ MachO::any_relocation_info MREPair;
+ MREPair.r_word0 = Value;
+ MREPair.r_word1 = ((0xffffff << 0) |
+ (Log2Size << 25) |
+ (MachO::ARM_RELOC_PAIR << 28));
+
+ Writer->addRelocation(Fragment->getParent(), MREPair);
+ }
+
Writer->addRelocation(Fragment->getParent(), MRE);
}
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