mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-10-09 18:55:33 +00:00
7b25ecf6ad
We on the linker to resolve calls to the appropriate BL/BLX instruction to make interworking function correctly. It uses the symbol in the relocation to do that, so we need to be careful about being too clever. To enable this for ARM mode, split the BL/BLX fixup kind off from the unconditional-branch fixups. rdar://10927209 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151571 91177308-0d34-0410-b5e6-96231b3b80d8
282 lines
9.1 KiB
C++
282 lines
9.1 KiB
C++
//===-- ARMELFObjectWriter.cpp - ARM 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 };
|
|
unsigned GetRelocTypeInner(const MCValue &Target,
|
|
const MCFixup &Fixup,
|
|
bool IsPCRel) const;
|
|
|
|
|
|
public:
|
|
ARMELFObjectWriter(uint8_t OSABI);
|
|
|
|
virtual ~ARMELFObjectWriter();
|
|
|
|
virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
|
|
bool IsPCRel, bool IsRelocWithSymbol,
|
|
int64_t Addend) const;
|
|
virtual unsigned getEFlags() const;
|
|
virtual const MCSymbol *ExplicitRelSym(const MCAssembler &Asm,
|
|
const MCValue &Target,
|
|
const MCFragment &F,
|
|
const MCFixup &Fixup,
|
|
bool IsPCRel) 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().AliasedSymbol();
|
|
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: llvm_unreachable("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:
|
|
llvm_unreachable("unimplemented");
|
|
case MCSymbolRefExpr::VK_ARM_GOTTPOFF:
|
|
Type = ELF::R_ARM_TLS_IE32;
|
|
break;
|
|
}
|
|
break;
|
|
case ARM::fixup_arm_bl:
|
|
case ARM::fixup_arm_blx:
|
|
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:
|
|
Type = ELF::R_ARM_THM_CALL;
|
|
break;
|
|
}
|
|
} else {
|
|
switch ((unsigned)Fixup.getKind()) {
|
|
default: llvm_unreachable("invalid fixup kind!");
|
|
case FK_Data_4:
|
|
switch (Modifier) {
|
|
default: llvm_unreachable("Unsupported Modifier");
|
|
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;
|
|
case MCSymbolRefExpr::VK_ARM_TARGET1:
|
|
Type = ELF::R_ARM_TARGET1;
|
|
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:
|
|
llvm_unreachable("Unimplemented");
|
|
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);
|
|
}
|