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

   1 //===-- AArch64MCExpr.cpp - AArch64 specific MC expression classes --------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file contains the implementation of the assembly expression modifiers
  11 // accepted by the AArch64 architecture (e.g. ":lo12:", ":gottprel_g1:", ...).
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "AArch64MCExpr.h"
  16 #include "llvm/MC/MCAssembler.h"
  17 #include "llvm/MC/MCContext.h"
  18 #include "llvm/MC/MCELF.h"
  19 #include "llvm/MC/MCSymbol.h"
  20 #include "llvm/MC/MCValue.h"
  21 #include "llvm/Object/ELF.h"
  22 #include "llvm/Support/ErrorHandling.h"
  23
  24 using namespace llvm;
  25
  26 #define DEBUG_TYPE "aarch64symbolrefexpr"
  27
  28 const AArch64MCExpr *AArch64MCExpr::Create(const MCExpr *Expr, VariantKind Kind,
  29                                        MCContext &Ctx) {
  30   return new (Ctx) AArch64MCExpr(Expr, Kind);
  31 }
  32
  33 StringRef AArch64MCExpr::getVariantKindName() const {
  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_DTPREL_G2:           return ":dtprel_g2:";
  48   case VK_DTPREL_G1:           return ":dtprel_g1:";
  49   case VK_DTPREL_G1_NC:        return ":dtprel_g1_nc:";
  50   case VK_DTPREL_G0:           return ":dtprel_g0:";
  51   case VK_DTPREL_G0_NC:        return ":dtprel_g0_nc:";
  52   case VK_DTPREL_HI12:         return ":dtprel_hi12:";
  53   case VK_DTPREL_LO12:         return ":dtprel_lo12:";
  54   case VK_DTPREL_LO12_NC:      return ":dtprel_lo12_nc:";
  55   case VK_TPREL_G2:            return ":tprel_g2:";
  56   case VK_TPREL_G1:            return ":tprel_g1:";
  57   case VK_TPREL_G1_NC:         return ":tprel_g1_nc:";
  58   case VK_TPREL_G0:            return ":tprel_g0:";
  59   case VK_TPREL_G0_NC:         return ":tprel_g0_nc:";
  60   case VK_TPREL_HI12:          return ":tprel_hi12:";
  61   case VK_TPREL_LO12:          return ":tprel_lo12:";
  62   case VK_TPREL_LO12_NC:       return ":tprel_lo12_nc:";
  63   case VK_TLSDESC_LO12:        return ":tlsdesc_lo12:";
  64   case VK_ABS_PAGE:            return "";
  65   case VK_GOT_PAGE:            return ":got:";
  66   case VK_GOT_LO12:            return ":got_lo12:";
  67   case VK_GOTTPREL_PAGE:       return ":gottprel:";
  68   case VK_GOTTPREL_LO12_NC:    return ":gottprel_lo12:";
  69   case VK_GOTTPREL_G1:         return ":gottprel_g1:";
  70   case VK_GOTTPREL_G0_NC:      return ":gottprel_g0_nc:";
  71   case VK_TLSDESC:             return "";
  72   case VK_TLSDESC_PAGE:        return ":tlsdesc:";
  73   default:
  74     llvm_unreachable("Invalid ELF symbol kind");
  75   }
  76 }
  77
  78 void AArch64MCExpr::PrintImpl(raw_ostream &OS) const {
  79   if (getKind() != VK_NONE)
  80     OS << getVariantKindName();
  81   OS << *Expr;
  82 }
  83
  84 void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const {
  85   Streamer.visitUsedExpr(*getSubExpr());
  86 }
  87
  88 const MCSection *AArch64MCExpr::FindAssociatedSection() const {
  89   llvm_unreachable("FIXME: what goes here?");
  90 }
  91
  92 bool AArch64MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
  93                                             const MCAsmLayout *Layout,
  94                                             const MCFixup *Fixup) const {
  95   if (!getSubExpr()->EvaluateAsRelocatable(Res, Layout, Fixup))
  96     return false;
  97
  98   Res =
  99       MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind());
 100
 101   return true;
 102 }
 103
 104 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) {
 105   switch (Expr->getKind()) {
 106   case MCExpr::Target:
 107     llvm_unreachable("Can't handle nested target expression");
 108     break;
 109   case MCExpr::Constant:
 110     break;
 111
 112   case MCExpr::Binary: {
 113     const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr);
 114     fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm);
 115     fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm);
 116     break;
 117   }
 118
 119   case MCExpr::SymbolRef: {
 120     // We're known to be under a TLS fixup, so any symbol should be
 121     // modified. There should be only one.
 122     const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr);
 123     MCSymbolData &SD = Asm.getOrCreateSymbolData(SymRef.getSymbol());
 124     MCELF::SetType(SD, ELF::STT_TLS);
 125     break;
 126   }
 127
 128   case MCExpr::Unary:
 129     fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm);
 130     break;
 131   }
 132 }
 133
 134 void AArch64MCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
 135   switch (getSymbolLoc(Kind)) {
 136   default:
 137     return;
 138   case VK_DTPREL:
 139   case VK_GOTTPREL:
 140   case VK_TPREL:
 141   case VK_TLSDESC:
 142     break;
 143   }
 144
 145   fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm);
 146 }