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      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   LinkerRequiresNonEmptyDwarfLines = false;
     36   MaxInstLength = 4;
     37   MinInstAlignment = 1;
     38   PCSymbol = "$";
     39   SeparatorString = ";";
     40   CommentColumn = 40;
     41   CommentString = "#";
     42   LabelSuffix = ":";
     43   DebugLabelSuffix = ":";
     44   GlobalPrefix = "";
     45   PrivateGlobalPrefix = ".";
     46   LinkerPrivateGlobalPrefix = "";
     47   InlineAsmStart = "APP";
     48   InlineAsmEnd = "NO_APP";
     49   Code16Directive = ".code16";
     50   Code32Directive = ".code32";
     51   Code64Directive = ".code64";
     52   AssemblerDialect = 0;
     53   AllowQuotesInName = false;
     54   AllowNameToStartWithDigit = false;
     55   AllowPeriodsInName = true;
     56   AllowUTF8 = true;
     57   UseDataRegionDirectives = false;
     58   ZeroDirective = "\t.zero\t";
     59   AsciiDirective = "\t.ascii\t";
     60   AscizDirective = "\t.asciz\t";
     61   Data8bitsDirective = "\t.byte\t";
     62   Data16bitsDirective = "\t.short\t";
     63   Data32bitsDirective = "\t.long\t";
     64   Data64bitsDirective = "\t.quad\t";
     65   SunStyleELFSectionSwitchSyntax = false;
     66   UsesELFSectionDirectiveForBSS = false;
     67   AlignDirective = "\t.align\t";
     68   AlignmentIsInBytes = true;
     69   TextAlignFillValue = 0;
     70   GPRel64Directive = 0;
     71   GPRel32Directive = 0;
     72   GlobalDirective = "\t.globl\t";
     73   HasSetDirective = true;
     74   HasAggressiveSymbolFolding = true;
     75   COMMDirectiveAlignmentIsInBytes = true;
     76   LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
     77   HasDotTypeDotSizeDirective = true;
     78   HasSingleParameterDotFile = true;
     79   HasNoDeadStrip = false;
     80   HasSymbolResolver = false;
     81   WeakRefDirective = 0;
     82   WeakDefDirective = 0;
     83   LinkOnceDirective = 0;
     84   HiddenVisibilityAttr = MCSA_Hidden;
     85   HiddenDeclarationVisibilityAttr = MCSA_Hidden;
     86   ProtectedVisibilityAttr = MCSA_Protected;
     87   HasLEB128 = false;
     88   SupportsDebugInformation = false;
     89   ExceptionsType = ExceptionHandling::None;
     90   DwarfUsesInlineInfoSection = false;
     91   DwarfUsesRelocationsAcrossSections = true;
     92   DwarfRegNumForCFI = false;
     93   HasMicrosoftFastStdCallMangling = false;
     94   NeedsDwarfSectionOffsetDirective = false;
     95 }
     96 
     97 MCAsmInfo::~MCAsmInfo() {
     98 }
     99 
    100 
    101 unsigned MCAsmInfo::getULEB128Size(uint64_t Value) {
    102   unsigned Size = 0;
    103   do {
    104     Value >>= 7;
    105     Size += sizeof(int8_t);
    106   } while (Value);
    107   return Size;
    108 }
    109 
    110 unsigned MCAsmInfo::getSLEB128Size(int64_t Value) {
    111   unsigned Size = 0;
    112   int Sign = Value >> (8 * sizeof(Value) - 1);
    113   bool IsMore;
    114 
    115   do {
    116     unsigned Byte = Value & 0x7f;
    117     Value >>= 7;
    118     IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
    119     Size += sizeof(int8_t);
    120   } while (IsMore);
    121   return Size;
    122 }
    123 
    124 const MCExpr *
    125 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
    126                                        unsigned Encoding,
    127                                        MCStreamer &Streamer) const {
    128   return getExprForFDESymbol(Sym, Encoding, Streamer);
    129 }
    130 
    131 const MCExpr *
    132 MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
    133                                unsigned Encoding,
    134                                MCStreamer &Streamer) const {
    135   if (!(Encoding & dwarf::DW_EH_PE_pcrel))
    136     return MCSymbolRefExpr::Create(Sym, Streamer.getContext());
    137 
    138   MCContext &Context = Streamer.getContext();
    139   const MCExpr *Res = MCSymbolRefExpr::Create(Sym, Context);
    140   MCSymbol *PCSym = Context.CreateTempSymbol();
    141   Streamer.EmitLabel(PCSym);
    142   const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, Context);
    143   return MCBinaryExpr::CreateSub(Res, PC, Context);
    144 }
    145