Move the ARM specific parts of the ELF writer to Target/ARM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147115 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp b/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
new file mode 100644
index 0000000..b669a48
--- /dev/null
+++ b/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
@@ -0,0 +1,286 @@
+//===-- X86ELFObjectWriter.cpp - X86 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/ARMFixupKinds.h"
+#include "MCTargetDesc/ARMMCTargetDesc.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/MC/MCELFObjectWriter.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCValue.h"
+
+using namespace llvm;
+
+namespace {
+ class ARMELFObjectWriter : public MCELFObjectTargetWriter {
+ enum { DefaultEABIVersion = 0x05000000U };
+
+ const MCSymbol *ExplicitRelSym(const MCAssembler &Asm,
+ const MCValue &Target,
+ const MCFragment &F,
+ const MCFixup &Fixup,
+ bool IsPCRel) const;
+ unsigned GetRelocTypeInner(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const;
+
+
+ public:
+ ARMELFObjectWriter(uint8_t OSABI);
+
+ virtual ~ARMELFObjectWriter();
+ protected:
+ virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
+ bool IsPCRel, bool IsRelocWithSymbol,
+ int64_t Addend) const;
+ virtual unsigned getEFlags() const;
+ };
+}
+
+ARMELFObjectWriter::ARMELFObjectWriter(uint8_t OSABI)
+ : MCELFObjectTargetWriter(/*Is64Bit*/ false, OSABI,
+ ELF::EM_ARM,
+ /*HasRelocationAddend*/ false) {}
+
+ARMELFObjectWriter::~ARMELFObjectWriter() {}
+
+// FIXME: get the real EABI Version from the Triple.
+unsigned ARMELFObjectWriter::getEFlags() const {
+ return ELF::EF_ARM_EABIMASK & DefaultEABIVersion;
+}
+
+// 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();
+ bool EmitThisSym = false;
+
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(Symbol.getSection());
+ bool InNormalSection = true;
+ unsigned RelocType = 0;
+ RelocType = GetRelocTypeInner(Target, Fixup, IsPCRel);
+
+ DEBUG(
+ const MCSymbolRefExpr::VariantKind Kind = Target.getSymA()->getKind();
+ MCSymbolRefExpr::VariantKind Kind2;
+ Kind2 = Target.getSymB() ? Target.getSymB()->getKind() :
+ MCSymbolRefExpr::VK_None;
+ dbgs() << "considering symbol "
+ << Section.getSectionName() << "/"
+ << Symbol.getName() << "/"
+ << " Rel:" << (unsigned)RelocType
+ << " Kind: " << (int)Kind << "/" << (int)Kind2
+ << " 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;
+ }
+ }
+
+ if (EmitThisSym)
+ return &Symbol;
+ if (! Symbol.isTemporary() && InNormalSection) {
+ return &Symbol;
+ }
+ return NULL;
+}
+
+// Need to examine the Fixup when determining whether to
+// emit the relocation as an explicit symbol or as a section relative
+// offset
+unsigned ARMELFObjectWriter::GetRelocType(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel,
+ bool IsRelocWithSymbol,
+ int64_t Addend) const {
+ return GetRelocTypeInner(Target, Fixup, IsPCRel);
+}
+
+unsigned ARMELFObjectWriter::GetRelocTypeInner(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const {
+ MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
+ MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
+
+ unsigned Type = 0;
+ if (IsPCRel) {
+ switch ((unsigned)Fixup.getKind()) {
+ default: assert(0 && "Unimplemented");
+ case FK_Data_4:
+ switch (Modifier) {
+ default: llvm_unreachable("Unsupported Modifier");
+ case MCSymbolRefExpr::VK_None:
+ Type = ELF::R_ARM_REL32;
+ break;
+ case MCSymbolRefExpr::VK_ARM_TLSGD:
+ assert(0 && "unimplemented");
+ break;
+ case MCSymbolRefExpr::VK_ARM_GOTTPOFF:
+ Type = ELF::R_ARM_TLS_IE32;
+ break;
+ }
+ break;
+ case ARM::fixup_arm_uncondbranch:
+ switch (Modifier) {
+ case MCSymbolRefExpr::VK_ARM_PLT:
+ Type = ELF::R_ARM_PLT32;
+ break;
+ default:
+ Type = ELF::R_ARM_CALL;
+ break;
+ }
+ break;
+ case ARM::fixup_arm_condbranch:
+ Type = ELF::R_ARM_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:
+ case ARM::fixup_arm_thumb_blx:
+ switch (Modifier) {
+ case MCSymbolRefExpr::VK_ARM_PLT:
+ Type = ELF::R_ARM_THM_CALL;
+ break;
+ default:
+ Type = ELF::R_ARM_NONE;
+ break;
+ }
+ break;
+ }
+ } else {
+ switch ((unsigned)Fixup.getKind()) {
+ default: llvm_unreachable("invalid fixup kind!");
+ case FK_Data_4:
+ switch (Modifier) {
+ default: llvm_unreachable("Unsupported Modifier"); break;
+ case MCSymbolRefExpr::VK_ARM_GOT:
+ Type = ELF::R_ARM_GOT_BREL;
+ break;
+ case MCSymbolRefExpr::VK_ARM_TLSGD:
+ Type = ELF::R_ARM_TLS_GD32;
+ break;
+ case MCSymbolRefExpr::VK_ARM_TPOFF:
+ Type = ELF::R_ARM_TLS_LE32;
+ break;
+ case MCSymbolRefExpr::VK_ARM_GOTTPOFF:
+ Type = ELF::R_ARM_TLS_IE32;
+ break;
+ case MCSymbolRefExpr::VK_None:
+ Type = ELF::R_ARM_ABS32;
+ break;
+ case MCSymbolRefExpr::VK_ARM_GOTOFF:
+ Type = ELF::R_ARM_GOTOFF32;
+ break;
+ }
+ break;
+ case ARM::fixup_arm_ldst_pcrel_12:
+ case ARM::fixup_arm_pcrel_10:
+ case ARM::fixup_arm_adr_pcrel_12:
+ case ARM::fixup_arm_thumb_bl:
+ case ARM::fixup_arm_thumb_cb:
+ case ARM::fixup_arm_thumb_cp:
+ case ARM::fixup_arm_thumb_br:
+ assert(0 && "Unimplemented");
+ break;
+ case ARM::fixup_arm_uncondbranch:
+ Type = ELF::R_ARM_CALL;
+ break;
+ case ARM::fixup_arm_condbranch:
+ Type = ELF::R_ARM_JUMP24;
+ break;
+ case ARM::fixup_arm_movt_hi16:
+ Type = ELF::R_ARM_MOVT_ABS;
+ break;
+ case ARM::fixup_arm_movw_lo16:
+ Type = ELF::R_ARM_MOVW_ABS_NC;
+ break;
+ case ARM::fixup_t2_movt_hi16:
+ Type = ELF::R_ARM_THM_MOVT_ABS;
+ break;
+ case ARM::fixup_t2_movw_lo16:
+ Type = ELF::R_ARM_THM_MOVW_ABS_NC;
+ break;
+ }
+ }
+
+ return Type;
+}
+
+MCObjectWriter *llvm::createARMELFObjectWriter(raw_ostream &OS,
+ uint8_t OSABI) {
+ MCELFObjectTargetWriter *MOTW = new ARMELFObjectWriter(OSABI);
+ return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/true);
+}