src/llvm/lib/MC/MCAsmInfo.cpp

   1 //===-- MCAsmInfo.cpp - Asm Info -------------------------------------------==//
   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 defines target asm properties related what form asm statements
  11 // should take.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/MC/MCAsmInfo.h"
  16 #include "llvm/MC/MCContext.h"
  17 #include "llvm/MC/MCExpr.h"
  18 #include "llvm/MC/MCStreamer.h"
  19 #include "llvm/Support/DataTypes.h"
  20 #include "llvm/Support/Dwarf.h"
  21 #include <cctype>
  22 #include <cstring>
  23 using namespace llvm;
  24
  25 MCAsmInfo::MCAsmInfo() {
  26   PointerSize = 4;
  27   CalleeSaveStackSlotSize = 4;
  28
  29   IsLittleEndian = true;
  30   StackGrowsUp = false;
  31   HasSubsectionsViaSymbols = false;
  32   HasMachoZeroFillDirective = false;
  33   HasMachoTBSSDirective = false;
  34   HasStaticCtorDtorReferenceInStaticMode = false;
  35   MaxInstLength = 4;
  36   MinInstAlignment = 1;
  37   DollarIsPC = false;
  38   SeparatorString = ";";
  39   CommentString = "#";
  40   LabelSuffix = ":";
  41   UseAssignmentForEHBegin = false;
  42   PrivateGlobalPrefix = "L";
  43   PrivateLabelPrefix = PrivateGlobalPrefix;
  44   LinkerPrivateGlobalPrefix = "";
  45   InlineAsmStart = "APP";
  46   InlineAsmEnd = "NO_APP";
  47   Code16Directive = ".code16";
  48   Code32Directive = ".code32";
  49   Code64Directive = ".code64";
  50   AssemblerDialect = 0;
  51   AllowAtInName = false;
  52   UseDataRegionDirectives = false;
  53   ZeroDirective = "\t.zero\t";
  54   AsciiDirective = "\t.ascii\t";
  55   AscizDirective = "\t.asciz\t";
  56   Data8bitsDirective = "\t.byte\t";
  57   Data16bitsDirective = "\t.short\t";
  58   Data32bitsDirective = "\t.long\t";
  59   Data64bitsDirective = "\t.quad\t";
  60   SunStyleELFSectionSwitchSyntax = false;
  61   UsesELFSectionDirectiveForBSS = false;
  62   AlignmentIsInBytes = true;
  63   TextAlignFillValue = 0;
  64   GPRel64Directive = nullptr;
  65   GPRel32Directive = nullptr;
  66   GlobalDirective = "\t.globl\t";
  67   SetDirectiveSuppressesReloc = false;
  68   HasAggressiveSymbolFolding = true;
  69   COMMDirectiveAlignmentIsInBytes = true;
  70   LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
  71   HasDotTypeDotSizeDirective = true;
  72   HasSingleParameterDotFile = true;
  73   HasIdentDirective = false;
  74   HasNoDeadStrip = false;
  75   WeakDirective = "\t.weak\t";
  76   WeakRefDirective = nullptr;
  77   HasWeakDefDirective = false;
  78   HasWeakDefCanBeHiddenDirective = false;
  79   HasLinkOnceDirective = false;
  80   HiddenVisibilityAttr = MCSA_Hidden;
  81   HiddenDeclarationVisibilityAttr = MCSA_Hidden;
  82   ProtectedVisibilityAttr = MCSA_Protected;
  83   SupportsDebugInformation = false;
  84   ExceptionsType = ExceptionHandling::None;
  85   WinEHEncodingType = WinEH::EncodingType::Invalid;
  86   DwarfUsesRelocationsAcrossSections = true;
  87   DwarfFDESymbolsUseAbsDiff = false;
  88   DwarfRegNumForCFI = false;
  89   NeedsDwarfSectionOffsetDirective = false;
  90   UseParensForSymbolVariant = false;
  91
  92   // FIXME: Clang's logic should be synced with the logic used to initialize
  93   //        this member and the two implementations should be merged.
  94   // For reference:
  95   // - Solaris always enables the integrated assembler by default
  96   //   - SparcELFMCAsmInfo and X86ELFMCAsmInfo are handling this case
  97   // - Windows always enables the integrated assembler by default
  98   //   - MCAsmInfoCOFF is handling this case, should it be MCAsmInfoMicrosoft?
  99   // - MachO targets always enables the integrated assembler by default
 100   //   - MCAsmInfoDarwin is handling this case
 101   // - Generic_GCC toolchains enable the integrated assembler on a per
 102   //   architecture basis.
 103   //   - The target subclasses for AArch64, ARM, and X86 handle these cases
 104   UseIntegratedAssembler = false;
 105
 106   CompressDebugSections = false;
 107 }
 108
 109 MCAsmInfo::~MCAsmInfo() {
 110 }
 111
 112 bool MCAsmInfo::isSectionAtomizableBySymbols(const MCSection &Section) const {
 113   return false;
 114 }
 115
 116 const MCExpr *
 117 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
 118                                        unsigned Encoding,
 119                                        MCStreamer &Streamer) const {
 120   return getExprForFDESymbol(Sym, Encoding, Streamer);
 121 }
 122
 123 const MCExpr *
 124 MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
 125                                unsigned Encoding,
 126                                MCStreamer &Streamer) const {
 127   if (!(Encoding & dwarf::DW_EH_PE_pcrel))
 128     return MCSymbolRefExpr::Create(Sym, Streamer.getContext());
 129
 130   MCContext &Context = Streamer.getContext();
 131   const MCExpr *Res = MCSymbolRefExpr::Create(Sym, Context);
 132   MCSymbol *PCSym = Context.CreateTempSymbol();
 133   Streamer.EmitLabel(PCSym);
 134   const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, Context);
 135   return MCBinaryExpr::CreateSub(Res, PC, Context);
 136 }