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/ErrorHandling.h" 21 22 using namespace llvm; 23 24 #define DEBUG_TYPE "aarch64symbolrefexpr" 25 26 const AArch64MCExpr *AArch64MCExpr::create(const MCExpr *Expr, VariantKind Kind, 27 MCContext &Ctx) { 28 return new (Ctx) AArch64MCExpr(Expr, Kind); 29 } 30 31 StringRef AArch64MCExpr::getVariantKindName() const { 32 switch (static_cast<uint32_t>(getKind())) { 33 case VK_CALL: return ""; 34 case VK_LO12: return ":lo12:"; 35 case VK_ABS_G3: return ":abs_g3:"; 36 case VK_ABS_G2: return ":abs_g2:"; 37 case VK_ABS_G2_S: return ":abs_g2_s:"; 38 case VK_ABS_G2_NC: return ":abs_g2_nc:"; 39 case VK_ABS_G1: return ":abs_g1:"; 40 case VK_ABS_G1_S: return ":abs_g1_s:"; 41 case VK_ABS_G1_NC: return ":abs_g1_nc:"; 42 case VK_ABS_G0: return ":abs_g0:"; 43 case VK_ABS_G0_S: return ":abs_g0_s:"; 44 case VK_ABS_G0_NC: return ":abs_g0_nc:"; 45 case VK_PREL_G3: return ":prel_g3:"; 46 case VK_PREL_G2: return ":prel_g2:"; 47 case VK_PREL_G2_NC: return ":prel_g2_nc:"; 48 case VK_PREL_G1: return ":prel_g1:"; 49 case VK_PREL_G1_NC: return ":prel_g1_nc:"; 50 case VK_PREL_G0: return ":prel_g0:"; 51 case VK_PREL_G0_NC: return ":prel_g0_nc:"; 52 case VK_DTPREL_G2: return ":dtprel_g2:"; 53 case VK_DTPREL_G1: return ":dtprel_g1:"; 54 case VK_DTPREL_G1_NC: return ":dtprel_g1_nc:"; 55 case VK_DTPREL_G0: return ":dtprel_g0:"; 56 case VK_DTPREL_G0_NC: return ":dtprel_g0_nc:"; 57 case VK_DTPREL_HI12: return ":dtprel_hi12:"; 58 case VK_DTPREL_LO12: return ":dtprel_lo12:"; 59 case VK_DTPREL_LO12_NC: return ":dtprel_lo12_nc:"; 60 case VK_TPREL_G2: return ":tprel_g2:"; 61 case VK_TPREL_G1: return ":tprel_g1:"; 62 case VK_TPREL_G1_NC: return ":tprel_g1_nc:"; 63 case VK_TPREL_G0: return ":tprel_g0:"; 64 case VK_TPREL_G0_NC: return ":tprel_g0_nc:"; 65 case VK_TPREL_HI12: return ":tprel_hi12:"; 66 case VK_TPREL_LO12: return ":tprel_lo12:"; 67 case VK_TPREL_LO12_NC: return ":tprel_lo12_nc:"; 68 case VK_TLSDESC_LO12: return ":tlsdesc_lo12:"; 69 case VK_ABS_PAGE: return ""; 70 case VK_ABS_PAGE_NC: return ":pg_hi21_nc:"; 71 case VK_GOT: return ":got:"; 72 case VK_GOT_PAGE: return ":got:"; 73 case VK_GOT_LO12: return ":got_lo12:"; 74 case VK_GOTTPREL: return ":gottprel:"; 75 case VK_GOTTPREL_PAGE: return ":gottprel:"; 76 case VK_GOTTPREL_LO12_NC: return ":gottprel_lo12:"; 77 case VK_GOTTPREL_G1: return ":gottprel_g1:"; 78 case VK_GOTTPREL_G0_NC: return ":gottprel_g0_nc:"; 79 case VK_TLSDESC: return ""; 80 case VK_TLSDESC_PAGE: return ":tlsdesc:"; 81 case VK_SECREL_LO12: return ":secrel_lo12:"; 82 case VK_SECREL_HI12: return ":secrel_hi12:"; 83 default: 84 llvm_unreachable("Invalid ELF symbol kind"); 85 } 86 } 87 88 void AArch64MCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const { 89 OS << getVariantKindName(); 90 Expr->print(OS, MAI); 91 } 92 93 void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const { 94 Streamer.visitUsedExpr(*getSubExpr()); 95 } 96 97 MCFragment *AArch64MCExpr::findAssociatedFragment() const { 98 llvm_unreachable("FIXME: what goes here?"); 99 } 100 101 bool AArch64MCExpr::evaluateAsRelocatableImpl(MCValue &Res, 102 const MCAsmLayout *Layout, 103 const MCFixup *Fixup) const { 104 if (!getSubExpr()->evaluateAsRelocatable(Res, Layout, Fixup)) 105 return false; 106 107 Res = 108 MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind()); 109 110 return true; 111 } 112 113 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) { 114 switch (Expr->getKind()) { 115 case MCExpr::Target: 116 llvm_unreachable("Can't handle nested target expression"); 117 break; 118 case MCExpr::Constant: 119 break; 120 121 case MCExpr::Binary: { 122 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr); 123 fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm); 124 fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm); 125 break; 126 } 127 128 case MCExpr::SymbolRef: { 129 // We're known to be under a TLS fixup, so any symbol should be 130 // modified. There should be only one. 131 const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr); 132 cast<MCSymbolELF>(SymRef.getSymbol()).setType(ELF::STT_TLS); 133 break; 134 } 135 136 case MCExpr::Unary: 137 fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm); 138 break; 139 } 140 } 141 142 void AArch64MCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const { 143 switch (getSymbolLoc(Kind)) { 144 default: 145 return; 146 case VK_DTPREL: 147 case VK_GOTTPREL: 148 case VK_TPREL: 149 case VK_TLSDESC: 150 break; 151 } 152 153 fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm); 154 } 155