public:
ARMELFObjectWriter(uint8_t OSABI);
- virtual ~ARMELFObjectWriter();
+ ~ARMELFObjectWriter() override;
unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
bool IsPCRel) const override;
- const MCSymbol *ExplicitRelSym(const MCAssembler &Asm,
- const MCValue &Target, const MCFragment &F,
- const MCFixup &Fixup,
- bool IsPCRel) const override;
+
+ bool needsRelocateWithSymbol(const MCSymbol &Sym,
+ unsigned Type) const override;
};
}
ARMELFObjectWriter::~ARMELFObjectWriter() {}
-// In ARM, _MergedGlobals and other most symbols get emitted directly.
-// I.e. not as an offset to a section symbol.
-// This code is an approximation of what ARM/gcc does.
-
-STATISTIC(PCRelCount, "Total number of PIC Relocations");
-STATISTIC(NonPCRelCount, "Total number of non-PIC relocations");
-
-const MCSymbol *ARMELFObjectWriter::ExplicitRelSym(const MCAssembler &Asm,
- const MCValue &Target,
- const MCFragment &F,
- const MCFixup &Fixup,
- bool IsPCRel) const {
- const MCSymbol &Symbol = Target.getSymA()->getSymbol().AliasedSymbol();
- bool EmitThisSym = false;
-
- const MCSectionELF &Section =
- static_cast<const MCSectionELF&>(Symbol.getSection());
- bool InNormalSection = true;
- unsigned RelocType = 0;
- RelocType = GetRelocTypeInner(Target, Fixup, IsPCRel);
- assert(!Target.getSymB() ||
- Target.getSymB()->getKind() == MCSymbolRefExpr::VK_None);
+bool ARMELFObjectWriter::needsRelocateWithSymbol(const MCSymbol &Sym,
+ unsigned Type) const {
+ // FIXME: This is extremely conservative. This really needs to use a
+ // whitelist with a clear explanation for why each realocation needs to
+ // point to the symbol, not to the section.
+ switch (Type) {
+ default:
+ return true;
- DEBUG(
- MCSymbolRefExpr::VariantKind Kind = Fixup.getAccessVariant();
- dbgs() << "considering symbol "
- << Section.getSectionName() << "/"
- << Symbol.getName() << "/"
- << " Rel:" << (unsigned)RelocType
- << " Kind: " << (int)Kind
- << " Tmp:"
- << Symbol.isAbsolute() << "/" << Symbol.isDefined() << "/"
- << Symbol.isVariable() << "/" << Symbol.isTemporary()
- << " Counts:" << PCRelCount << "/" << NonPCRelCount << "\n");
-
- if (IsPCRel) { ++PCRelCount;
- switch (RelocType) {
- default:
- // Most relocation types are emitted as explicit symbols
- InNormalSection =
- StringSwitch<bool>(Section.getSectionName())
- .Case(".data.rel.ro.local", false)
- .Case(".data.rel", false)
- .Case(".bss", false)
- .Default(true);
- EmitThisSym = true;
- break;
- case ELF::R_ARM_ABS32:
- // But things get strange with R_ARM_ABS32
- // In this case, most things that go in .rodata show up
- // as section relative relocations
- InNormalSection =
- StringSwitch<bool>(Section.getSectionName())
- .Case(".data.rel.ro.local", false)
- .Case(".data.rel", false)
- .Case(".rodata", false)
- .Case(".bss", false)
- .Default(true);
- EmitThisSym = false;
- break;
- }
- } else {
- NonPCRelCount++;
- InNormalSection =
- StringSwitch<bool>(Section.getSectionName())
- .Case(".data.rel.ro.local", false)
- .Case(".rodata", false)
- .Case(".data.rel", false)
- .Case(".bss", false)
- .Default(true);
-
- switch (RelocType) {
- default: EmitThisSym = true; break;
- case ELF::R_ARM_ABS32: EmitThisSym = false; break;
- case ELF::R_ARM_PREL31: EmitThisSym = false; break;
- }
+ case ELF::R_ARM_PREL31:
+ case ELF::R_ARM_ABS32:
+ return false;
}
-
- if (EmitThisSym)
- return &Symbol;
- if (! Symbol.isTemporary() && InNormalSection) {
- return &Symbol;
- }
- return NULL;
}
// Need to examine the Fixup when determining whether to
unsigned ARMELFObjectWriter::GetRelocTypeInner(const MCValue &Target,
const MCFixup &Fixup,
bool IsPCRel) const {
- MCSymbolRefExpr::VariantKind Modifier = Fixup.getAccessVariant();
+ MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
unsigned Type = 0;
if (IsPCRel) {
switch ((unsigned)Fixup.getKind()) {
- default: llvm_unreachable("Unimplemented");
+ default:
+ report_fatal_error("unsupported relocation on symbol");
+ return ELF::R_ARM_NONE;
case FK_Data_4:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_GOTTPOFF:
Type = ELF::R_ARM_TLS_IE32;
break;
+ case MCSymbolRefExpr::VK_GOTPCREL:
+ Type = ELF::R_ARM_GOT_PREL;
+ break;
}
break;
case ARM::fixup_arm_blx:
case ARM::fixup_arm_uncondbl:
switch (Modifier) {
case MCSymbolRefExpr::VK_PLT:
- Type = ELF::R_ARM_PLT32;
+ Type = ELF::R_ARM_CALL;
break;
case MCSymbolRefExpr::VK_ARM_TLSCALL:
Type = ELF::R_ARM_TLS_CALL;
Type = ELF::R_ARM_THM_JUMP24;
break;
case ARM::fixup_arm_movt_hi16:
- case ARM::fixup_arm_movt_hi16_pcrel:
Type = ELF::R_ARM_MOVT_PREL;
break;
case ARM::fixup_arm_movw_lo16:
- case ARM::fixup_arm_movw_lo16_pcrel:
Type = ELF::R_ARM_MOVW_PREL_NC;
break;
case ARM::fixup_t2_movt_hi16:
- case ARM::fixup_t2_movt_hi16_pcrel:
Type = ELF::R_ARM_THM_MOVT_PREL;
break;
case ARM::fixup_t2_movw_lo16:
- case ARM::fixup_t2_movw_lo16_pcrel:
Type = ELF::R_ARM_THM_MOVW_PREL_NC;
break;
case ARM::fixup_arm_thumb_bl:
}
} else {
switch ((unsigned)Fixup.getKind()) {
- default: llvm_unreachable("invalid fixup kind!");
+ default:
+ report_fatal_error("unsupported relocation on symbol");
+ return ELF::R_ARM_NONE;
+ case FK_Data_1:
+ switch (Modifier) {
+ default: llvm_unreachable("unsupported Modifier");
+ case MCSymbolRefExpr::VK_None:
+ Type = ELF::R_ARM_ABS8;
+ break;
+ }
+ break;
+ case FK_Data_2:
+ switch (Modifier) {
+ default: llvm_unreachable("unsupported modifier");
+ case MCSymbolRefExpr::VK_None:
+ Type = ELF::R_ARM_ABS16;
+ break;
+ }
+ break;
case FK_Data_4:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_GOTOFF:
Type = ELF::R_ARM_GOTOFF32;
break;
+ case MCSymbolRefExpr::VK_GOTPCREL:
+ Type = ELF::R_ARM_GOT_PREL;
+ break;
case MCSymbolRefExpr::VK_ARM_TARGET1:
Type = ELF::R_ARM_TARGET1;
break;
case MCSymbolRefExpr::VK_ARM_PREL31:
Type = ELF::R_ARM_PREL31;
break;
+ case MCSymbolRefExpr::VK_ARM_SBREL:
+ Type = ELF::R_ARM_SBREL32;
+ break;
case MCSymbolRefExpr::VK_ARM_TLSLDO:
Type = ELF::R_ARM_TLS_LDO32;
break;
return Type;
}
-MCObjectWriter *llvm::createARMELFObjectWriter(raw_ostream &OS,
+MCObjectWriter *llvm::createARMELFObjectWriter(raw_pwrite_stream &OS,
uint8_t OSABI,
bool IsLittleEndian) {
MCELFObjectTargetWriter *MOTW = new ARMELFObjectWriter(OSABI);