SystemZMCObjectWriter.cpp [plain text]
#include "MCTargetDesc/SystemZMCTargetDesc.h"
#include "MCTargetDesc/SystemZMCFixups.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCValue.h"
using namespace llvm;
namespace {
class SystemZObjectWriter : public MCELFObjectTargetWriter {
public:
SystemZObjectWriter(uint8_t OSABI);
virtual ~SystemZObjectWriter();
protected:
virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
bool IsPCRel, bool IsRelocWithSymbol,
int64_t Addend) const LLVM_OVERRIDE;
virtual const MCSymbol *ExplicitRelSym(const MCAssembler &Asm,
const MCValue &Target,
const MCFragment &F,
const MCFixup &Fixup,
bool IsPCRel) const LLVM_OVERRIDE;
};
}
SystemZObjectWriter::SystemZObjectWriter(uint8_t OSABI)
: MCELFObjectTargetWriter(true, OSABI, ELF::EM_S390,
true) {}
SystemZObjectWriter::~SystemZObjectWriter() {
}
static unsigned getAbsoluteReloc(unsigned Kind) {
switch (Kind) {
case FK_Data_1: return ELF::R_390_8;
case FK_Data_2: return ELF::R_390_16;
case FK_Data_4: return ELF::R_390_32;
case FK_Data_8: return ELF::R_390_64;
}
llvm_unreachable("Unsupported absolute address");
}
static unsigned getPCRelReloc(unsigned Kind) {
switch (Kind) {
case FK_Data_2: return ELF::R_390_PC16;
case FK_Data_4: return ELF::R_390_PC32;
case FK_Data_8: return ELF::R_390_PC64;
case SystemZ::FK_390_PC16DBL: return ELF::R_390_PC16DBL;
case SystemZ::FK_390_PC32DBL: return ELF::R_390_PC32DBL;
case SystemZ::FK_390_PLT16DBL: return ELF::R_390_PLT16DBL;
case SystemZ::FK_390_PLT32DBL: return ELF::R_390_PLT32DBL;
}
llvm_unreachable("Unsupported PC-relative address");
}
static unsigned getTLSLEReloc(unsigned Kind) {
switch (Kind) {
case FK_Data_4: return ELF::R_390_TLS_LE32;
case FK_Data_8: return ELF::R_390_TLS_LE64;
}
llvm_unreachable("Unsupported absolute address");
}
static unsigned getPLTReloc(unsigned Kind) {
switch (Kind) {
case SystemZ::FK_390_PC16DBL: return ELF::R_390_PLT16DBL;
case SystemZ::FK_390_PC32DBL: return ELF::R_390_PLT32DBL;
}
llvm_unreachable("Unsupported absolute address");
}
unsigned SystemZObjectWriter::GetRelocType(const MCValue &Target,
const MCFixup &Fixup,
bool IsPCRel,
bool IsRelocWithSymbol,
int64_t Addend) const {
MCSymbolRefExpr::VariantKind Modifier = (Target.isAbsolute() ?
MCSymbolRefExpr::VK_None :
Target.getSymA()->getKind());
unsigned Kind = Fixup.getKind();
switch (Modifier) {
case MCSymbolRefExpr::VK_None:
if (IsPCRel)
return getPCRelReloc(Kind);
return getAbsoluteReloc(Kind);
case MCSymbolRefExpr::VK_NTPOFF:
assert(!IsPCRel && "NTPOFF shouldn't be PC-relative");
return getTLSLEReloc(Kind);
case MCSymbolRefExpr::VK_GOT:
if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)
return ELF::R_390_GOTENT;
llvm_unreachable("Only PC-relative GOT accesses are supported for now");
case MCSymbolRefExpr::VK_PLT:
assert(IsPCRel && "@PLT shouldt be PC-relative");
return getPLTReloc(Kind);
default:
llvm_unreachable("Modifier not supported");
}
}
const MCSymbol *SystemZObjectWriter::ExplicitRelSym(const MCAssembler &Asm,
const MCValue &Target,
const MCFragment &F,
const MCFixup &Fixup,
bool IsPCRel) const {
if (!Target.isAbsolute() &&
Target.getSymA()->getKind() != MCSymbolRefExpr::VK_None &&
IsPCRel)
return &Target.getSymA()->getSymbol().AliasedSymbol();
return NULL;
}
MCObjectWriter *llvm::createSystemZObjectWriter(raw_ostream &OS,
uint8_t OSABI) {
MCELFObjectTargetWriter *MOTW = new SystemZObjectWriter(OSABI);
return createELFObjectWriter(MOTW, OS, false);
}