224 lines · cpp
1//===-- SystemZELFObjectWriter.cpp - SystemZ ELF writer -------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "MCTargetDesc/SystemZMCAsmInfo.h"10#include "MCTargetDesc/SystemZMCFixups.h"11#include "MCTargetDesc/SystemZMCTargetDesc.h"12#include "llvm/BinaryFormat/ELF.h"13#include "llvm/MC/MCContext.h"14#include "llvm/MC/MCELFObjectWriter.h"15#include "llvm/MC/MCExpr.h"16#include "llvm/MC/MCFixup.h"17#include "llvm/MC/MCObjectWriter.h"18#include "llvm/MC/MCValue.h"19#include "llvm/Support/ErrorHandling.h"20#include <cassert>21#include <cstdint>22#include <memory>23 24using namespace llvm;25 26namespace {27 28class SystemZELFObjectWriter : public MCELFObjectTargetWriter {29public:30 SystemZELFObjectWriter(uint8_t OSABI);31 ~SystemZELFObjectWriter() override = default;32 33protected:34 // Override MCELFObjectTargetWriter.35 unsigned getRelocType(const MCFixup &, const MCValue &,36 bool IsPCRel) const override;37 bool needsRelocateWithSymbol(const MCValue &, unsigned Type) const override;38 unsigned getAbsoluteReloc(SMLoc Loc, unsigned Kind) const;39 unsigned getPCRelReloc(SMLoc Loc, unsigned Kind) const;40};41 42} // end anonymous namespace43 44SystemZELFObjectWriter::SystemZELFObjectWriter(uint8_t OSABI)45 : MCELFObjectTargetWriter(/*Is64Bit_=*/true, OSABI, ELF::EM_S390,46 /*HasRelocationAddend_=*/true) {}47 48// Return the relocation type for an absolute value of MCFixupKind Kind.49unsigned SystemZELFObjectWriter::getAbsoluteReloc(SMLoc Loc,50 unsigned Kind) const {51 switch (Kind) {52 case FK_Data_1:53 case SystemZ::FK_390_U8Imm:54 case SystemZ::FK_390_S8Imm:55 return ELF::R_390_8;56 case SystemZ::FK_390_U12Imm:57 return ELF::R_390_12;58 case FK_Data_2:59 case SystemZ::FK_390_U16Imm:60 case SystemZ::FK_390_S16Imm:61 return ELF::R_390_16;62 case SystemZ::FK_390_S20Imm:63 return ELF::R_390_20;64 case FK_Data_4:65 case SystemZ::FK_390_U32Imm:66 case SystemZ::FK_390_S32Imm:67 return ELF::R_390_32;68 case FK_Data_8:69 return ELF::R_390_64;70 }71 reportError(Loc, "Unsupported absolute address");72 return 0;73}74 75// Return the relocation type for a PC-relative value of MCFixupKind Kind.76unsigned SystemZELFObjectWriter::getPCRelReloc(SMLoc Loc, unsigned Kind) const {77 switch (Kind) {78 case FK_Data_2:79 case SystemZ::FK_390_U16Imm:80 case SystemZ::FK_390_S16Imm:81 return ELF::R_390_PC16;82 case FK_Data_4:83 case SystemZ::FK_390_U32Imm:84 case SystemZ::FK_390_S32Imm:85 return ELF::R_390_PC32;86 case FK_Data_8:87 return ELF::R_390_PC64;88 case SystemZ::FK_390_PC12DBL:89 return ELF::R_390_PC12DBL;90 case SystemZ::FK_390_PC16DBL:91 return ELF::R_390_PC16DBL;92 case SystemZ::FK_390_PC24DBL:93 return ELF::R_390_PC24DBL;94 case SystemZ::FK_390_PC32DBL:95 return ELF::R_390_PC32DBL;96 }97 reportError(Loc, "Unsupported PC-relative address");98 return 0;99}100 101unsigned SystemZELFObjectWriter::getRelocType(const MCFixup &Fixup,102 const MCValue &Target,103 bool IsPCRel) const {104 SMLoc Loc = Fixup.getLoc();105 unsigned Kind = Fixup.getKind();106 auto Specifier = SystemZ::Specifier(Target.getSpecifier());107 switch (Specifier) {108 case SystemZ::S_INDNTPOFF:109 case SystemZ::S_NTPOFF:110 case SystemZ::S_TLSGD:111 case SystemZ::S_TLSLD:112 case SystemZ::S_TLSLDM:113 case SystemZ::S_DTPOFF:114 if (auto *SA = const_cast<MCSymbol *>(Target.getAddSym()))115 static_cast<MCSymbolELF *>(SA)->setType(ELF::STT_TLS);116 break;117 default:118 break;119 }120 121 switch (Specifier) {122 case SystemZ::S_None:123 if (IsPCRel)124 return getPCRelReloc(Loc, Kind);125 return getAbsoluteReloc(Loc, Kind);126 127 case SystemZ::S_NTPOFF:128 assert(!IsPCRel && "NTPOFF shouldn't be PC-relative");129 switch (Kind) {130 case FK_Data_4:131 return ELF::R_390_TLS_LE32;132 case FK_Data_8:133 return ELF::R_390_TLS_LE64;134 }135 reportError(Loc, "Unsupported thread-local address (local-exec)");136 return 0;137 138 case SystemZ::S_INDNTPOFF:139 if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)140 return ELF::R_390_TLS_IEENT;141 reportError(Loc,142 "Only PC-relative INDNTPOFF accesses are supported for now");143 return 0;144 145 case SystemZ::S_DTPOFF:146 assert(!IsPCRel && "DTPOFF shouldn't be PC-relative");147 switch (Kind) {148 case FK_Data_4:149 return ELF::R_390_TLS_LDO32;150 case FK_Data_8:151 return ELF::R_390_TLS_LDO64;152 }153 reportError(Loc, "Unsupported thread-local address (local-dynamic)");154 return 0;155 156 case SystemZ::S_TLSLDM:157 assert(!IsPCRel && "TLSLDM shouldn't be PC-relative");158 switch (Kind) {159 case FK_Data_4:160 return ELF::R_390_TLS_LDM32;161 case FK_Data_8:162 return ELF::R_390_TLS_LDM64;163 case SystemZ::FK_390_TLS_CALL:164 return ELF::R_390_TLS_LDCALL;165 }166 reportError(Loc, "Unsupported thread-local address (local-dynamic)");167 return 0;168 169 case SystemZ::S_TLSGD:170 assert(!IsPCRel && "TLSGD shouldn't be PC-relative");171 switch (Kind) {172 case FK_Data_4:173 return ELF::R_390_TLS_GD32;174 case FK_Data_8:175 return ELF::R_390_TLS_GD64;176 case SystemZ::FK_390_TLS_CALL:177 return ELF::R_390_TLS_GDCALL;178 }179 reportError(Loc, "Unsupported thread-local address (general-dynamic)");180 return 0;181 182 case SystemZ::S_GOT:183 case SystemZ::S_GOTENT:184 if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)185 return ELF::R_390_GOTENT;186 reportError(Loc, "Only PC-relative GOT accesses are supported for now");187 return 0;188 189 case SystemZ::S_PLT:190 assert(IsPCRel && "@PLT shouldn't be PC-relative");191 switch (Kind) {192 case SystemZ::FK_390_PC12DBL:193 return ELF::R_390_PLT12DBL;194 case SystemZ::FK_390_PC16DBL:195 return ELF::R_390_PLT16DBL;196 case SystemZ::FK_390_PC24DBL:197 return ELF::R_390_PLT24DBL;198 case SystemZ::FK_390_PC32DBL:199 return ELF::R_390_PLT32DBL;200 }201 reportError(Loc, "Unsupported PC-relative PLT address");202 return 0;203 204 default:205 llvm_unreachable("Modifier not supported");206 }207}208 209bool SystemZELFObjectWriter::needsRelocateWithSymbol(const MCValue &V,210 unsigned Type) const {211 switch (V.getSpecifier()) {212 case SystemZ::S_GOT:213 case SystemZ::S_PLT:214 return true;215 default:216 return false;217 }218}219 220std::unique_ptr<MCObjectTargetWriter>221llvm::createSystemZELFObjectWriter(uint8_t OSABI) {222 return std::make_unique<SystemZELFObjectWriter>(OSABI);223}224