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_DTPREL_G2: return ":dtprel_g2:"; 46 case VK_DTPREL_G1: return ":dtprel_g1:"; 47 case VK_DTPREL_G1_NC: return ":dtprel_g1_nc:"; 48 case VK_DTPREL_G0: return ":dtprel_g0:"; 49 case VK_DTPREL_G0_NC: return ":dtprel_g0_nc:"; 50 case VK_DTPREL_HI12: return ":dtprel_hi12:"; 51 case VK_DTPREL_LO12: return ":dtprel_lo12:"; 52 case VK_DTPREL_LO12_NC: return ":dtprel_lo12_nc:"; 53 case VK_TPREL_G2: return ":tprel_g2:"; 54 case VK_TPREL_G1: return ":tprel_g1:"; 55 case VK_TPREL_G1_NC: return ":tprel_g1_nc:"; 56 case VK_TPREL_G0: return ":tprel_g0:"; 57 case VK_TPREL_G0_NC: return ":tprel_g0_nc:"; 58 case VK_TPREL_HI12: return ":tprel_hi12:"; 59 case VK_TPREL_LO12: return ":tprel_lo12:"; 60 case VK_TPREL_LO12_NC: return ":tprel_lo12_nc:"; 61 case VK_TLSDESC_LO12: return ":tlsdesc_lo12:"; 62 case VK_ABS_PAGE: return ""; 63 case VK_ABS_PAGE_NC: return ":pg_hi21_nc:"; 64 case VK_GOT: return ":got:"; 65 case VK_GOT_PAGE: return ":got:"; 66 case VK_GOT_LO12: return ":got_lo12:"; 67 case VK_GOTTPREL: return ":gottprel:"; 68 case VK_GOTTPREL_PAGE: return ":gottprel:"; 69 case VK_GOTTPREL_LO12_NC: return ":gottprel_lo12:"; 70 case VK_GOTTPREL_G1: return ":gottprel_g1:"; 71 case VK_GOTTPREL_G0_NC: return ":gottprel_g0_nc:"; 72 case VK_TLSDESC: return ""; 73 case VK_TLSDESC_PAGE: return ":tlsdesc:"; 74 case VK_SECREL_LO12: return ":secrel_lo12:"; 75 case VK_SECREL_HI12: return ":secrel_hi12:"; 76 default: 77 llvm_unreachable("Invalid ELF symbol kind"); 78 } 79 } 80 81 void AArch64MCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const { 82 OS << getVariantKindName(); 83 Expr->print(OS, MAI); 84 } 85 86 void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const { 87 Streamer.visitUsedExpr(*getSubExpr()); 88 } 89 90 MCFragment *AArch64MCExpr::findAssociatedFragment() const { 91 llvm_unreachable("FIXME: what goes here?"); 92 } 93 94 bool AArch64MCExpr::evaluateAsRelocatableImpl(MCValue &Res, 95 const MCAsmLayout *Layout, 96 const MCFixup *Fixup) const { 97 if (!getSubExpr()->evaluateAsRelocatable(Res, Layout, Fixup)) 98 return false; 99 100 Res = 101 MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind()); 102 103 return true; 104 } 105 106 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) { 107 switch (Expr->getKind()) { 108 case MCExpr::Target: 109 llvm_unreachable("Can't handle nested target expression"); 110 break; 111 case MCExpr::Constant: 112 break; 113 114 case MCExpr::Binary: { 115 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr); 116 fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm); 117 fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm); 118 break; 119 } 120 121 case MCExpr::SymbolRef: { 122 // We're known to be under a TLS fixup, so any symbol should be 123 // modified. There should be only one. 124 const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr); 125 cast<MCSymbolELF>(SymRef.getSymbol()).setType(ELF::STT_TLS); 126 break; 127 } 128 129 case MCExpr::Unary: 130 fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm); 131 break; 132 } 133 } 134 135 void AArch64MCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const { 136 switch (getSymbolLoc(Kind)) { 137 default: 138 return; 139 case VK_DTPREL: 140 case VK_GOTTPREL: 141 case VK_TPREL: 142 case VK_TLSDESC: 143 break; 144 } 145 146 fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm); 147 } 148