1 files changed, 140 insertions, 0 deletions
diff --git a/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp b/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
new file mode 100644
index 0000000000..36e3d83d4d
--- /dev/null
+++ b/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
@@ -0,0 +1,140 @@
+//===-- SystemZMCObjectWriter.cpp - SystemZ ELF writer --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#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:
+  // Override MCELFObjectTargetWriter.
+  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;
+};
+} // end anonymouse namespace
+
+SystemZObjectWriter::SystemZObjectWriter(uint8_t OSABI)
+  : MCELFObjectTargetWriter(/*Is64Bit=*/true, OSABI, ELF::EM_S390,
+                            /*HasRelocationAddend=*/ true) {}
+
+SystemZObjectWriter::~SystemZObjectWriter() {
+}
+
+// Return the relocation type for an absolute value of MCFixupKind Kind.
+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");
+}
+
+// Return the relocation type for a PC-relative value of MCFixupKind Kind.
+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");
+}
+
+// Return the R_390_TLS_LE* relocation type for MCFixupKind Kind.
+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");
+}
+
+// Return the PLT relocation counterpart of MCFixupKind Kind.
+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 {
+  // The addend in a PC-relative R_390_* relocation is always applied to
+  // the PC-relative part of the address.  If some kind of indirection
+  // is applied to the symbol first, we can't use an addend there too.
+  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, /*IsLittleEndian=*/false);
+}