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//===-- AArch64ELFObjectWriter.cpp - AArch64 ELF Writer -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file handles ELF-specific object emission, converting LLVM's internal
// fixups into the appropriate relocations.
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/AArch64FixupKinds.h"
#include "MCTargetDesc/AArch64MCExpr.h"
#include "MCTargetDesc/AArch64MCTargetDesc.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
#include <cstdint>
using namespace llvm;
namespace {
class AArch64ELFObjectWriter : public MCELFObjectTargetWriter {
public:
AArch64ELFObjectWriter(uint8_t OSABI, bool IsLittleEndian, bool IsILP32);
~AArch64ELFObjectWriter() override = default;
protected:
unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
const MCFixup &Fixup, bool IsPCRel) const override;
bool IsILP32;
};
} // end anonymous namespace
AArch64ELFObjectWriter::AArch64ELFObjectWriter(uint8_t OSABI,
bool IsLittleEndian,
bool IsILP32)
: MCELFObjectTargetWriter(/*Is64Bit*/ true, OSABI, ELF::EM_AARCH64,
/*HasRelocationAddend*/ true),
IsILP32(IsILP32) {}
#define R_CLS(rtype) \
IsILP32 ? ELF::R_AARCH64_P32_##rtype : ELF::R_AARCH64_##rtype
#define BAD_ILP32_MOV(lp64rtype) "ILP32 absolute MOV relocation not "\
"supported (LP64 eqv: " #lp64rtype ")"
// assumes IsILP32 is true
static bool isNonILP32reloc(const MCFixup &Fixup,
AArch64MCExpr::VariantKind RefKind,
MCContext &Ctx) {
if ((unsigned)Fixup.getKind() != AArch64::fixup_aarch64_movw)
return false;
switch(RefKind) {
case AArch64MCExpr::VK_ABS_G3:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_UABS_G3));
return true;
case AArch64MCExpr::VK_ABS_G2:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_UABS_G2));
return true;
case AArch64MCExpr::VK_ABS_G2_S:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_SABS_G2));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_ABS_G2_NC:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_UABS_G2_NC));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_ABS_G1_S:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_SABS_G1));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_ABS_G1_NC:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_UABS_G1_NC));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_DTPREL_G2:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSLD_MOVW_DTPREL_G2));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_DTPREL_G1_NC:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSLD_MOVW_DTPREL_G1_NC));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_TPREL_G2:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSLE_MOVW_TPREL_G2));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_TPREL_G1_NC:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSLE_MOVW_TPREL_G1_NC));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_GOTTPREL_G1:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSIE_MOVW_GOTTPREL_G1));
return ELF::R_AARCH64_NONE;
case AArch64MCExpr::VK_GOTTPREL_G0_NC:
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSIE_MOVW_GOTTPREL_G0_NC));
return ELF::R_AARCH64_NONE;
default: return false;
}
return false;
}
unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
const MCValue &Target,
const MCFixup &Fixup,
bool IsPCRel) const {
AArch64MCExpr::VariantKind RefKind =
static_cast<AArch64MCExpr::VariantKind>(Target.getRefKind());
AArch64MCExpr::VariantKind SymLoc = AArch64MCExpr::getSymbolLoc(RefKind);
bool IsNC = AArch64MCExpr::isNotChecked(RefKind);
assert((!Target.getSymA() ||
Target.getSymA()->getKind() == MCSymbolRefExpr::VK_None) &&
"Should only be expression-level modifiers here");
assert((!Target.getSymB() ||
Target.getSymB()->getKind() == MCSymbolRefExpr::VK_None) &&
"Should only be expression-level modifiers here");
if (IsPCRel) {
switch ((unsigned)Fixup.getKind()) {
case FK_Data_1:
Ctx.reportError(Fixup.getLoc(), "1-byte data relocations not supported");
return ELF::R_AARCH64_NONE;
case FK_Data_2:
return R_CLS(PREL16);
case FK_Data_4:
return R_CLS(PREL32);
case FK_Data_8:
if (IsILP32) {
Ctx.reportError(Fixup.getLoc(), "ILP32 8 byte PC relative data "
"relocation not supported (LP64 eqv: PREL64)");
return ELF::R_AARCH64_NONE;
} else
return ELF::R_AARCH64_PREL64;
case AArch64::fixup_aarch64_pcrel_adr_imm21:
assert(SymLoc == AArch64MCExpr::VK_NONE && "unexpected ADR relocation");
return R_CLS(ADR_PREL_LO21);
case AArch64::fixup_aarch64_pcrel_adrp_imm21:
if (SymLoc == AArch64MCExpr::VK_ABS && !IsNC)
return R_CLS(ADR_PREL_PG_HI21);
if (SymLoc == AArch64MCExpr::VK_GOT && !IsNC)
return R_CLS(ADR_GOT_PAGE);
if (SymLoc == AArch64MCExpr::VK_GOTTPREL && !IsNC)
return R_CLS(TLSIE_ADR_GOTTPREL_PAGE21);
if (SymLoc == AArch64MCExpr::VK_TLSDESC && !IsNC)
return R_CLS(TLSDESC_ADR_PAGE21);
Ctx.reportError(Fixup.getLoc(),
"invalid symbol kind for ADRP relocation");
return ELF::R_AARCH64_NONE;
case AArch64::fixup_aarch64_pcrel_branch26:
return R_CLS(JUMP26);
case AArch64::fixup_aarch64_pcrel_call26:
return R_CLS(CALL26);
case AArch64::fixup_aarch64_ldr_pcrel_imm19:
if (SymLoc == AArch64MCExpr::VK_GOTTPREL)
return R_CLS(TLSIE_LD_GOTTPREL_PREL19);
return R_CLS(LD_PREL_LO19);
case AArch64::fixup_aarch64_pcrel_branch14:
return R_CLS(TSTBR14);
case AArch64::fixup_aarch64_pcrel_branch19:
return R_CLS(CONDBR19);
default:
Ctx.reportError(Fixup.getLoc(), "Unsupported pc-relative fixup kind");
return ELF::R_AARCH64_NONE;
}
} else {
if (IsILP32 && isNonILP32reloc(Fixup, RefKind, Ctx))
return ELF::R_AARCH64_NONE;
switch ((unsigned)Fixup.getKind()) {
case FK_Data_1:
Ctx.reportError(Fixup.getLoc(), "1-byte data relocations not supported");
return ELF::R_AARCH64_NONE;
case FK_Data_2:
return R_CLS(ABS16);
case FK_Data_4:
return R_CLS(ABS32);
case FK_Data_8:
if (IsILP32) {
Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(ABS64));
return ELF::R_AARCH64_NONE;
} else
return ELF::R_AARCH64_ABS64;
case AArch64::fixup_aarch64_add_imm12:
if (RefKind == AArch64MCExpr::VK_DTPREL_HI12)
return R_CLS(TLSLD_ADD_DTPREL_HI12);
if (RefKind == AArch64MCExpr::VK_TPREL_HI12)
return R_CLS(TLSLE_ADD_TPREL_HI12);
if (RefKind == AArch64MCExpr::VK_DTPREL_LO12_NC)
return R_CLS(TLSLD_ADD_DTPREL_LO12_NC);
if (RefKind == AArch64MCExpr::VK_DTPREL_LO12)
return R_CLS(TLSLD_ADD_DTPREL_LO12);
if (RefKind == AArch64MCExpr::VK_TPREL_LO12_NC)
return R_CLS(TLSLE_ADD_TPREL_LO12_NC);
if (RefKind == AArch64MCExpr::VK_TPREL_LO12)
return R_CLS(TLSLE_ADD_TPREL_LO12);
if (RefKind == AArch64MCExpr::VK_TLSDESC_LO12)
return R_CLS(TLSDESC_ADD_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
return R_CLS(ADD_ABS_LO12_NC);
Ctx.reportError(Fixup.getLoc(),
"invalid fixup for add (uimm12) instruction");
return ELF::R_AARCH64_NONE;
case AArch64::fixup_aarch64_ldst_imm12_scale1:
if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
return R_CLS(LDST8_ABS_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
return R_CLS(TLSLD_LDST8_DTPREL_LO12);
if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
return R_CLS(TLSLD_LDST8_DTPREL_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
return R_CLS(TLSLE_LDST8_TPREL_LO12);
if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
return R_CLS(TLSLE_LDST8_TPREL_LO12_NC);
Ctx.reportError(Fixup.getLoc(),
"invalid fixup for 8-bit load/store instruction");
return ELF::R_AARCH64_NONE;
case AArch64::fixup_aarch64_ldst_imm12_scale2:
if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
return R_CLS(LDST16_ABS_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
return R_CLS(TLSLD_LDST16_DTPREL_LO12);
if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
return R_CLS(TLSLD_LDST16_DTPREL_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
return R_CLS(TLSLE_LDST16_TPREL_LO12);
if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
return R_CLS(TLSLE_LDST16_TPREL_LO12_NC);
Ctx.reportError(Fixup.getLoc(),
"invalid fixup for 16-bit load/store instruction");
return ELF::R_AARCH64_NONE;
case AArch64::fixup_aarch64_ldst_imm12_scale4:
if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
return R_CLS(LDST32_ABS_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
return R_CLS(TLSLD_LDST32_DTPREL_LO12);
if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
return R_CLS(TLSLD_LDST32_DTPREL_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
return R_CLS(TLSLE_LDST32_TPREL_LO12);
if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
return R_CLS(TLSLE_LDST32_TPREL_LO12_NC);
Ctx.reportError(Fixup.getLoc(),
"invalid fixup for 32-bit load/store instruction");
return ELF::R_AARCH64_NONE;
case AArch64::fixup_aarch64_ldst_imm12_scale8:
if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
return R_CLS(LDST64_ABS_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_GOT && IsNC)
return R_CLS(LD64_GOT_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
return R_CLS(TLSLD_LDST64_DTPREL_LO12);
if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
return R_CLS(TLSLD_LDST64_DTPREL_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
return R_CLS(TLSLE_LDST64_TPREL_LO12);
if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
return R_CLS(TLSLE_LDST64_TPREL_LO12_NC);
if (SymLoc == AArch64MCExpr::VK_GOTTPREL && IsNC)
return IsILP32 ? ELF::R_AARCH64_P32_TLSIE_LD32_GOTTPREL_LO12_NC
: ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC;
if (SymLoc == AArch64MCExpr::VK_TLSDESC && IsNC)
return IsILP32 ? ELF::R_AARCH64_P32_TLSDESC_LD32_LO12_NC
: ELF::R_AARCH64_TLSDESC_LD64_LO12_NC;
Ctx.reportError(Fixup.getLoc(),
"invalid fixup for 64-bit load/store instruction");
return ELF::R_AARCH64_NONE;
case AArch64::fixup_aarch64_ldst_imm12_scale16:
if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
return R_CLS(LDST128_ABS_LO12_NC);
Ctx.reportError(Fixup.getLoc(),
"invalid fixup for 128-bit load/store instruction");
return ELF::R_AARCH64_NONE;
// ILP32 case not reached here, tested with isNonILP32reloc
case AArch64::fixup_aarch64_movw:
if (RefKind == AArch64MCExpr::VK_ABS_G3)
return ELF::R_AARCH64_MOVW_UABS_G3;
if (RefKind == AArch64MCExpr::VK_ABS_G2)
return ELF::R_AARCH64_MOVW_UABS_G2;
if (RefKind == AArch64MCExpr::VK_ABS_G2_S)
return ELF::R_AARCH64_MOVW_SABS_G2;
if (RefKind == AArch64MCExpr::VK_ABS_G2_NC)
return ELF::R_AARCH64_MOVW_UABS_G2_NC;
if (RefKind == AArch64MCExpr::VK_ABS_G1)
return R_CLS(MOVW_UABS_G1);
if (RefKind == AArch64MCExpr::VK_ABS_G1_S)
return ELF::R_AARCH64_MOVW_SABS_G1;
if (RefKind == AArch64MCExpr::VK_ABS_G1_NC)
return ELF::R_AARCH64_MOVW_UABS_G1_NC;
if (RefKind == AArch64MCExpr::VK_ABS_G0)
return R_CLS(MOVW_UABS_G0);
if (RefKind == AArch64MCExpr::VK_ABS_G0_S)
return R_CLS(MOVW_SABS_G0);
if (RefKind == AArch64MCExpr::VK_ABS_G0_NC)
return R_CLS(MOVW_UABS_G0_NC);
if (RefKind == AArch64MCExpr::VK_DTPREL_G2)
return ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G2;
if (RefKind == AArch64MCExpr::VK_DTPREL_G1)
return R_CLS(TLSLD_MOVW_DTPREL_G1);
if (RefKind == AArch64MCExpr::VK_DTPREL_G1_NC)
return ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G1_NC;
if (RefKind == AArch64MCExpr::VK_DTPREL_G0)
return R_CLS(TLSLD_MOVW_DTPREL_G0);
if (RefKind == AArch64MCExpr::VK_DTPREL_G0_NC)
return R_CLS(TLSLD_MOVW_DTPREL_G0_NC);
if (RefKind == AArch64MCExpr::VK_TPREL_G2)
return ELF::R_AARCH64_TLSLE_MOVW_TPREL_G2;
if (RefKind == AArch64MCExpr::VK_TPREL_G1)
return R_CLS(TLSLE_MOVW_TPREL_G1);
if (RefKind == AArch64MCExpr::VK_TPREL_G1_NC)
return ELF::R_AARCH64_TLSLE_MOVW_TPREL_G1_NC;
if (RefKind == AArch64MCExpr::VK_TPREL_G0)
return R_CLS(TLSLE_MOVW_TPREL_G0);
if (RefKind == AArch64MCExpr::VK_TPREL_G0_NC)
return R_CLS(TLSLE_MOVW_TPREL_G0_NC);
if (RefKind == AArch64MCExpr::VK_GOTTPREL_G1)
return ELF::R_AARCH64_TLSIE_MOVW_GOTTPREL_G1;
if (RefKind == AArch64MCExpr::VK_GOTTPREL_G0_NC)
return ELF::R_AARCH64_TLSIE_MOVW_GOTTPREL_G0_NC;
Ctx.reportError(Fixup.getLoc(),
"invalid fixup for movz/movk instruction");
return ELF::R_AARCH64_NONE;
case AArch64::fixup_aarch64_tlsdesc_call:
return R_CLS(TLSDESC_CALL);
default:
Ctx.reportError(Fixup.getLoc(), "Unknown ELF relocation type");
return ELF::R_AARCH64_NONE;
}
}
llvm_unreachable("Unimplemented fixup -> relocation");
}
MCObjectWriter *llvm::createAArch64ELFObjectWriter(raw_pwrite_stream &OS,
uint8_t OSABI,
bool IsLittleEndian,
bool IsILP32) {
MCELFObjectTargetWriter *MOTW =
new AArch64ELFObjectWriter(OSABI, IsLittleEndian, IsILP32);
return createELFObjectWriter(MOTW, OS, IsLittleEndian);
}
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