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 NeedsLocalForSize = false; 43 PrivateGlobalPrefix = "L"; 44 PrivateLabelPrefix = PrivateGlobalPrefix; 45 LinkerPrivateGlobalPrefix = ""; 46 InlineAsmStart = "APP"; 47 InlineAsmEnd = "NO_APP"; 48 Code16Directive = ".code16"; 49 Code32Directive = ".code32"; 50 Code64Directive = ".code64"; 51 AssemblerDialect = 0; 52 AllowAtInName = false; 53 SupportsQuotedNames = true; 54 UseDataRegionDirectives = false; 55 ZeroDirective = "\t.zero\t"; 56 AsciiDirective = "\t.ascii\t"; 57 AscizDirective = "\t.asciz\t"; 58 Data8bitsDirective = "\t.byte\t"; 59 Data16bitsDirective = "\t.short\t"; 60 Data32bitsDirective = "\t.long\t"; 61 Data64bitsDirective = "\t.quad\t"; 62 SunStyleELFSectionSwitchSyntax = false; 63 UsesELFSectionDirectiveForBSS = false; 64 AlignmentIsInBytes = true; 65 TextAlignFillValue = 0; 66 GPRel64Directive = nullptr; 67 GPRel32Directive = nullptr; 68 GlobalDirective = "\t.globl\t"; 69 SetDirectiveSuppressesReloc = false; 70 HasAggressiveSymbolFolding = true; 71 COMMDirectiveAlignmentIsInBytes = true; 72 LCOMMDirectiveAlignmentType = LCOMM::NoAlignment; 73 HasFunctionAlignment = true; 74 HasDotTypeDotSizeDirective = true; 75 HasSingleParameterDotFile = true; 76 HasIdentDirective = false; 77 HasNoDeadStrip = false; 78 HasAltEntry = false; 79 WeakDirective = "\t.weak\t"; 80 WeakRefDirective = nullptr; 81 HasWeakDefDirective = false; 82 HasWeakDefCanBeHiddenDirective = false; 83 HasLinkOnceDirective = false; 84 HiddenVisibilityAttr = MCSA_Hidden; 85 HiddenDeclarationVisibilityAttr = MCSA_Hidden; 86 ProtectedVisibilityAttr = MCSA_Protected; 87 SupportsDebugInformation = false; 88 ExceptionsType = ExceptionHandling::None; 89 WinEHEncodingType = WinEH::EncodingType::Invalid; 90 DwarfUsesRelocationsAcrossSections = true; 91 DwarfFDESymbolsUseAbsDiff = false; 92 DwarfRegNumForCFI = false; 93 NeedsDwarfSectionOffsetDirective = false; 94 UseParensForSymbolVariant = false; 95 UseLogicalShr = true; 96 97 // FIXME: Clang's logic should be synced with the logic used to initialize 98 // this member and the two implementations should be merged. 99 // For reference: 100 // - Solaris always enables the integrated assembler by default 101 // - SparcELFMCAsmInfo and X86ELFMCAsmInfo are handling this case 102 // - Windows always enables the integrated assembler by default 103 // - MCAsmInfoCOFF is handling this case, should it be MCAsmInfoMicrosoft? 104 // - MachO targets always enables the integrated assembler by default 105 // - MCAsmInfoDarwin is handling this case 106 // - Generic_GCC toolchains enable the integrated assembler on a per 107 // architecture basis. 108 // - The target subclasses for AArch64, ARM, and X86 handle these cases 109 UseIntegratedAssembler = false; 110 PreserveAsmComments = true; 111 112 CompressDebugSections = DebugCompressionType::DCT_None; 113 } 114 115 MCAsmInfo::~MCAsmInfo() { 116 } 117 118 bool MCAsmInfo::isSectionAtomizableBySymbols(const MCSection &Section) const { 119 return false; 120 } 121 122 const MCExpr * 123 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym, 124 unsigned Encoding, 125 MCStreamer &Streamer) const { 126 return getExprForFDESymbol(Sym, Encoding, Streamer); 127 } 128 129 const MCExpr * 130 MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym, 131 unsigned Encoding, 132 MCStreamer &Streamer) const { 133 if (!(Encoding & dwarf::DW_EH_PE_pcrel)) 134 return MCSymbolRefExpr::create(Sym, Streamer.getContext()); 135 136 MCContext &Context = Streamer.getContext(); 137 const MCExpr *Res = MCSymbolRefExpr::create(Sym, Context); 138 MCSymbol *PCSym = Context.createTempSymbol(); 139 Streamer.EmitLabel(PCSym); 140 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, Context); 141 return MCBinaryExpr::createSub(Res, PC, Context); 142 } 143 144 static bool isAcceptableChar(char C) { 145 return (C >= 'a' && C <= 'z') || (C >= 'A' && C <= 'Z') || 146 (C >= '0' && C <= '9') || C == '_' || C == '$' || C == '.' || C == '@'; 147 } 148 149 bool MCAsmInfo::isValidUnquotedName(StringRef Name) const { 150 if (Name.empty()) 151 return false; 152 153 // If any of the characters in the string is an unacceptable character, force 154 // quotes. 155 for (char C : Name) { 156 if (!isAcceptableChar(C)) 157 return false; 158 } 159 160 return true; 161 } 162 163 bool MCAsmInfo::shouldOmitSectionDirective(StringRef SectionName) const { 164 // FIXME: Does .section .bss/.data/.text work everywhere?? 165 return SectionName == ".text" || SectionName == ".data" || 166 (SectionName == ".bss" && !usesELFSectionDirectiveForBSS()); 167 } 168
