llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp

   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_ABS_PAGE:            return "";
  72   case VK_ABS_PAGE_NC:         return ":pg_hi21_nc:";
  73   case VK_GOT:                 return ":got:";
  74   case VK_GOT_PAGE:            return ":got:";
  75   case VK_GOT_PAGE_LO15:       return ":gotpage_lo15:";
  76   case VK_GOT_LO12:            return ":got_lo12:";
  77   case VK_GOTTPREL:            return ":gottprel:";
  78   case VK_GOTTPREL_PAGE:       return ":gottprel:";
  79   case VK_GOTTPREL_LO12_NC:    return ":gottprel_lo12:";
  80   case VK_GOTTPREL_G1:         return ":gottprel_g1:";
  81   case VK_GOTTPREL_G0_NC:      return ":gottprel_g0_nc:";
  82   case VK_TLSDESC:             return "";
  83   case VK_TLSDESC_PAGE:        return ":tlsdesc:";
  84   case VK_SECREL_LO12:         return ":secrel_lo12:";
  85   case VK_SECREL_HI12:         return ":secrel_hi12:";
  86   case VK_GOT_AUTH:            return ":got_auth:";
  87   case VK_GOT_AUTH_PAGE:       return ":got_auth:";
  88   case VK_GOT_AUTH_LO12:       return ":got_auth_lo12:";
  89   default:
  90     llvm_unreachable("Invalid ELF symbol kind");
  91   }
  92   // clang-format on
  93 }
  94
  95 void AArch64MCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
  96   OS << getVariantKindName();
  97   Expr->print(OS, MAI);
  98 }
  99
 100 void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const {
 101   Streamer.visitUsedExpr(*getSubExpr());
 102 }
 103
 104 MCFragment *AArch64MCExpr::findAssociatedFragment() const {
 105   llvm_unreachable("FIXME: what goes here?");
 106 }
 107
 108 bool AArch64MCExpr::evaluateAsRelocatableImpl(MCValue &Res,
 109                                               const MCAssembler *Asm,
 110                                               const MCFixup *Fixup) const {
 111   if (!getSubExpr()->evaluateAsRelocatable(Res, Asm, Fixup))
 112     return false;
 113
 114   Res =
 115       MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind());
 116
 117   return true;
 118 }
 119
 120 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) {
 121   switch (Expr->getKind()) {
 122   case MCExpr::Target:
 123     llvm_unreachable("Can't handle nested target expression");
 124     break;
 125   case MCExpr::Constant:
 126     break;
 127
 128   case MCExpr::Binary: {
 129     const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr);
 130     fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm);
 131     fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm);
 132     break;
 133   }
 134
 135   case MCExpr::SymbolRef: {
 136     // We're known to be under a TLS fixup, so any symbol should be
 137     // modified. There should be only one.
 138     const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr);
 139     cast<MCSymbolELF>(SymRef.getSymbol()).setType(ELF::STT_TLS);
 140     break;
 141   }
 142
 143   case MCExpr::Unary:
 144     fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm);
 145     break;
 146   }
 147 }
 148
 149 void AArch64MCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
 150   switch (getSymbolLoc(Kind)) {
 151   default:
 152     return;
 153   case VK_DTPREL:
 154   case VK_GOTTPREL:
 155   case VK_TPREL:
 156   case VK_TLSDESC:
 157     break;
 158   }
 159
 160   fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm);
 161 }
 162
 163 const AArch64AuthMCExpr *AArch64AuthMCExpr::create(const MCExpr *Expr,
 164                                                    uint16_t Discriminator,
 165                                                    AArch64PACKey::ID Key,
 166                                                    bool HasAddressDiversity,
 167                                                    MCContext &Ctx) {
 168   return new (Ctx)
 169       AArch64AuthMCExpr(Expr, Discriminator, Key, HasAddressDiversity);
 170 }
 171
 172 void AArch64AuthMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
 173   bool WrapSubExprInParens = !isa<MCSymbolRefExpr>(getSubExpr());
 174   if (WrapSubExprInParens)
 175     OS << '(';
 176   getSubExpr()->print(OS, MAI);
 177   if (WrapSubExprInParens)
 178     OS << ')';
 179
 180   OS << "@AUTH(" << AArch64PACKeyIDToString(Key) << ',' << Discriminator;
 181   if (hasAddressDiversity())
 182     OS << ",addr";
 183   OS << ')';
 184 }
 185
 186 void AArch64AuthMCExpr::visitUsedExpr(MCStreamer &Streamer) const {
 187   Streamer.visitUsedExpr(*getSubExpr());
 188 }
 189
 190 MCFragment *AArch64AuthMCExpr::findAssociatedFragment() const {
 191   llvm_unreachable("FIXME: what goes here?");
 192 }
 193
 194 bool AArch64AuthMCExpr::evaluateAsRelocatableImpl(MCValue &Res,
 195                                                   const MCAssembler *Asm,
 196                                                   const MCFixup *Fixup) const {
 197   if (!getSubExpr()->evaluateAsRelocatable(Res, Asm, Fixup))
 198     return false;
 199
 200   if (Res.getSymB())
 201     report_fatal_error("Auth relocation can't reference two symbols");
 202
 203   Res = MCValue::get(Res.getSymA(), nullptr, Res.getConstant(), getKind());
 204   return true;
 205 }