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