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