1 //===-- AArch64MCExpr.cpp - AArch64 specific MC expression classes --------===// 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains the implementation of the assembly expression modifiers 10 // accepted by the AArch64 architecture (e.g. ":lo12:", ":gottprel_g1:", ...). 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "AArch64MCExpr.h" 15 #include "llvm/BinaryFormat/ELF.h" 16 #include "llvm/MC/MCContext.h" 17 #include "llvm/MC/MCStreamer.h" 18 #include "llvm/MC/MCSymbolELF.h" 19 #include "llvm/MC/MCValue.h" 20 #include "llvm/Support/Casting.h" 21 #include "llvm/Support/ErrorHandling.h" 22 23 using namespace llvm; 24 25 #define DEBUG_TYPE "aarch64symbolrefexpr" 26 27 const AArch64MCExpr *AArch64MCExpr::create(const MCExpr *Expr, VariantKind Kind, 28 MCContext &Ctx) { 29 return new (Ctx) AArch64MCExpr(Expr, Kind); 30 } 31 32 StringRef AArch64MCExpr::getVariantKindName() const { 33 // clang-format off 34 switch (static_cast<uint32_t>(getKind())) { 35 case VK_CALL: return ""; 36 case VK_LO12: return ":lo12:"; 37 case VK_ABS_G3: return ":abs_g3:"; 38 case VK_ABS_G2: return ":abs_g2:"; 39 case VK_ABS_G2_S: return ":abs_g2_s:"; 40 case VK_ABS_G2_NC: return ":abs_g2_nc:"; 41 case VK_ABS_G1: return ":abs_g1:"; 42 case VK_ABS_G1_S: return ":abs_g1_s:"; 43 case VK_ABS_G1_NC: return ":abs_g1_nc:"; 44 case VK_ABS_G0: return ":abs_g0:"; 45 case VK_ABS_G0_S: return ":abs_g0_s:"; 46 case VK_ABS_G0_NC: return ":abs_g0_nc:"; 47 case VK_PREL_G3: return ":prel_g3:"; 48 case VK_PREL_G2: return ":prel_g2:"; 49 case VK_PREL_G2_NC: return ":prel_g2_nc:"; 50 case VK_PREL_G1: return ":prel_g1:"; 51 case VK_PREL_G1_NC: return ":prel_g1_nc:"; 52 case VK_PREL_G0: return ":prel_g0:"; 53 case VK_PREL_G0_NC: return ":prel_g0_nc:"; 54 case VK_DTPREL_G2: return ":dtprel_g2:"; 55 case VK_DTPREL_G1: return ":dtprel_g1:"; 56 case VK_DTPREL_G1_NC: return ":dtprel_g1_nc:"; 57 case VK_DTPREL_G0: return ":dtprel_g0:"; 58 case VK_DTPREL_G0_NC: return ":dtprel_g0_nc:"; 59 case VK_DTPREL_HI12: return ":dtprel_hi12:"; 60 case VK_DTPREL_LO12: return ":dtprel_lo12:"; 61 case VK_DTPREL_LO12_NC: return ":dtprel_lo12_nc:"; 62 case VK_TPREL_G2: return ":tprel_g2:"; 63 case VK_TPREL_G1: return ":tprel_g1:"; 64 case VK_TPREL_G1_NC: return ":tprel_g1_nc:"; 65 case VK_TPREL_G0: return ":tprel_g0:"; 66 case VK_TPREL_G0_NC: return ":tprel_g0_nc:"; 67 case VK_TPREL_HI12: return ":tprel_hi12:"; 68 case VK_TPREL_LO12: return ":tprel_lo12:"; 69 case VK_TPREL_LO12_NC: return ":tprel_lo12_nc:"; 70 case VK_TLSDESC_LO12: return ":tlsdesc_lo12:"; 71 case VK_TLSDESC_AUTH_LO12: return ":tlsdesc_auth_lo12:"; 72 case VK_ABS_PAGE: return ""; 73 case VK_ABS_PAGE_NC: return ":pg_hi21_nc:"; 74 case VK_GOT: return ":got:"; 75 case VK_GOT_PAGE: return ":got:"; 76 case VK_GOT_PAGE_LO15: return ":gotpage_lo15:"; 77 case VK_GOT_LO12: return ":got_lo12:"; 78 case VK_GOTTPREL: return ":gottprel:"; 79 case VK_GOTTPREL_PAGE: return ":gottprel:"; 80 case VK_GOTTPREL_LO12_NC: return ":gottprel_lo12:"; 81 case VK_GOTTPREL_G1: return ":gottprel_g1:"; 82 case VK_GOTTPREL_G0_NC: return ":gottprel_g0_nc:"; 83 case VK_TLSDESC: return ""; 84 case VK_TLSDESC_PAGE: return ":tlsdesc:"; 85 case VK_TLSDESC_AUTH: return ""; 86 case VK_TLSDESC_AUTH_PAGE: return ":tlsdesc_auth:"; 87 case VK_SECREL_LO12: return ":secrel_lo12:"; 88 case VK_SECREL_HI12: return ":secrel_hi12:"; 89 case VK_GOT_AUTH: return ":got_auth:"; 90 case VK_GOT_AUTH_PAGE: return ":got_auth:"; 91 case VK_GOT_AUTH_LO12: return ":got_auth_lo12:"; 92 default: 93 llvm_unreachable("Invalid ELF symbol kind"); 94 } 95 // clang-format on 96 } 97 98 void AArch64MCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const { 99 OS << getVariantKindName(); 100 Expr->print(OS, MAI); 101 } 102 103 void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const { 104 Streamer.visitUsedExpr(*getSubExpr()); 105 } 106 107 MCFragment *AArch64MCExpr::findAssociatedFragment() const { 108 llvm_unreachable("FIXME: what goes here?"); 109 } 110 111 bool AArch64MCExpr::evaluateAsRelocatableImpl(MCValue &Res, 112 const MCAssembler *Asm, 113 const MCFixup *Fixup) const { 114 if (!getSubExpr()->evaluateAsRelocatable(Res, Asm, Fixup)) 115 return false; 116 117 Res = 118 MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind()); 119 120 return true; 121 } 122 123 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) { 124 switch (Expr->getKind()) { 125 case MCExpr::Target: 126 llvm_unreachable("Can't handle nested target expression"); 127 break; 128 case MCExpr::Constant: 129 break; 130 131 case MCExpr::Binary: { 132 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr); 133 fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm); 134 fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm); 135 break; 136 } 137 138 case MCExpr::SymbolRef: { 139 // We're known to be under a TLS fixup, so any symbol should be 140 // modified. There should be only one. 141 const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr); 142 cast<MCSymbolELF>(SymRef.getSymbol()).setType(ELF::STT_TLS); 143 break; 144 } 145 146 case MCExpr::Unary: 147 fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm); 148 break; 149 } 150 } 151 152 void AArch64MCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const { 153 switch (getSymbolLoc(Kind)) { 154 default: 155 return; 156 case VK_DTPREL: 157 case VK_GOTTPREL: 158 case VK_TPREL: 159 case VK_TLSDESC: 160 case VK_TLSDESC_AUTH: 161 break; 162 } 163 164 fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm); 165 } 166 167 const AArch64AuthMCExpr *AArch64AuthMCExpr::create(const MCExpr *Expr, 168 uint16_t Discriminator, 169 AArch64PACKey::ID Key, 170 bool HasAddressDiversity, 171 MCContext &Ctx) { 172 return new (Ctx) 173 AArch64AuthMCExpr(Expr, Discriminator, Key, HasAddressDiversity); 174 } 175 176 void AArch64AuthMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const { 177 bool WrapSubExprInParens = !isa<MCSymbolRefExpr>(getSubExpr()); 178 if (WrapSubExprInParens) 179 OS << '('; 180 getSubExpr()->print(OS, MAI); 181 if (WrapSubExprInParens) 182 OS << ')'; 183 184 OS << "@AUTH(" << AArch64PACKeyIDToString(Key) << ',' << Discriminator; 185 if (hasAddressDiversity()) 186 OS << ",addr"; 187 OS << ')'; 188 } 189 190 void AArch64AuthMCExpr::visitUsedExpr(MCStreamer &Streamer) const { 191 Streamer.visitUsedExpr(*getSubExpr()); 192 } 193 194 MCFragment *AArch64AuthMCExpr::findAssociatedFragment() const { 195 llvm_unreachable("FIXME: what goes here?"); 196 } 197 198 bool AArch64AuthMCExpr::evaluateAsRelocatableImpl(MCValue &Res, 199 const MCAssembler *Asm, 200 const MCFixup *Fixup) const { 201 if (!getSubExpr()->evaluateAsRelocatable(Res, Asm, Fixup)) 202 return false; 203 204 if (Res.getSymB()) 205 report_fatal_error("Auth relocation can't reference two symbols"); 206 207 Res = MCValue::get(Res.getSymA(), nullptr, Res.getConstant(), getKind()); 208 return true; 209 } 210