ARM/MC/ELF relocation "hello world" for movw/movt.
Lifted adjustFixupValue() from Darwin for sharing w ELF.
Test added
TODO:
refactor ELFObjectWriter::RecordRelocation more.
Possibly share more code with Darwin?
Lots more relocations...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120534 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index 4b97836..47c70ec 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -396,6 +396,10 @@
const MCFixup &Fixup, MCValue Target,
uint64_t &FixedValue);
+ protected:
+ // Fixme: pull up to ELFObjectWriter
+ unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
+ bool IsPCRel);
private:
static bool isFixupKindPCRel(unsigned Kind) {
switch (Kind) {
@@ -1434,13 +1438,105 @@
ARMELFObjectWriter::~ARMELFObjectWriter()
{}
+unsigned ARMELFObjectWriter::GetRelocType(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) {
+ MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
+ MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
+
+ if (IsPCRel) {
+ switch (Modifier) {
+ default: assert(0 && "Unimplemented Modifier");
+ case MCSymbolRefExpr::VK_None: break;
+ }
+ switch ((unsigned)Fixup.getKind()) {
+ default: assert(0 && "Unimplemented");
+ case ARM::fixup_arm_branch: return ELF::R_ARM_CALL; break;
+ }
+ } else {
+ switch ((unsigned)Fixup.getKind()) {
+ default: llvm_unreachable("invalid fixup kind!");
+ case ARM::fixup_arm_pcrel_12:
+ case ARM::fixup_arm_vfp_pcrel_12:
+ assert(0 && "Unimplemented"); break;
+ case ARM::fixup_arm_branch:
+ return ELF::R_ARM_CALL; break;
+ case ARM::fixup_arm_movt_hi16:
+ return ELF::R_ARM_MOVT_ABS; break;
+ case ARM::fixup_arm_movw_lo16:
+ return ELF::R_ARM_MOVW_ABS_NC; break;
+ }
+ }
+
+ if (RelocNeedsGOT(Modifier))
+ NeedsGOT = true;
+ return -1;
+}
+
void ARMELFObjectWriter::RecordRelocation(const MCAssembler &Asm,
const MCAsmLayout &Layout,
const MCFragment *Fragment,
const MCFixup &Fixup,
MCValue Target,
uint64_t &FixedValue) {
- assert(0 && "ARMELFObjectWriter::RecordRelocation() unimplemented");
+ int64_t Addend = 0;
+ int Index = 0;
+ int64_t Value = Target.getConstant();
+ const MCSymbol *RelocSymbol = NULL;
+
+ bool IsPCRel = isFixupKindPCRel(Fixup.getKind());
+ if (!Target.isAbsolute()) {
+ const MCSymbol &Symbol = Target.getSymA()->getSymbol();
+ const MCSymbol &ASymbol = Symbol.AliasedSymbol();
+ RelocSymbol = SymbolToReloc(Asm, Target, *Fragment);
+
+ if (const MCSymbolRefExpr *RefB = Target.getSymB()) {
+ const MCSymbol &SymbolB = RefB->getSymbol();
+ MCSymbolData &SDB = Asm.getSymbolData(SymbolB);
+ IsPCRel = true;
+ MCSectionData *Sec = Fragment->getParent();
+
+ // Offset of the symbol in the section
+ int64_t a = Layout.getSymbolAddress(&SDB) - Layout.getSectionAddress(Sec);
+
+ // Ofeset of the relocation in the section
+ int64_t b = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
+ Value += b - a;
+ }
+
+ if (!RelocSymbol) {
+ MCSymbolData &SD = Asm.getSymbolData(ASymbol);
+ MCFragment *F = SD.getFragment();
+
+ Index = F->getParent()->getOrdinal() + 1;
+
+ MCSectionData *FSD = F->getParent();
+ // Offset of the symbol in the section
+ Value += Layout.getSymbolAddress(&SD) - Layout.getSectionAddress(FSD);
+ } else {
+ if (Asm.getSymbolData(Symbol).getFlags() & ELF_Other_Weakref)
+ WeakrefUsedInReloc.insert(RelocSymbol);
+ else
+ UsedInReloc.insert(RelocSymbol);
+ Index = -1;
+ }
+ Addend = Value;
+ // Compensate for the addend on i386.
+ if (Is64Bit)
+ Value = 0;
+ }
+
+ FixedValue = Value;
+
+ // determine the type of the relocation
+ unsigned Type = GetRelocType(Target, Fixup, IsPCRel);
+
+ uint64_t RelocOffset = Layout.getFragmentOffset(Fragment) +
+ Fixup.getOffset();
+
+ if (!HasRelocationAddend) Addend = 0;
+ ELFRelocationEntry ERE(RelocOffset, Index, Type, RelocSymbol, Addend);
+ Relocations[Fragment->getParent()].push_back(ERE);
}
//===- MBlazeELFObjectWriter -------------------------------------------===//