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 WeakDirective = "\t.weak\t"; 79 WeakRefDirective = nullptr; 80 HasWeakDefDirective = false; 81 HasWeakDefCanBeHiddenDirective = false; 82 HasLinkOnceDirective = false; 83 HiddenVisibilityAttr = MCSA_Hidden; 84 HiddenDeclarationVisibilityAttr = MCSA_Hidden; 85 ProtectedVisibilityAttr = MCSA_Protected; 86 SupportsDebugInformation = false; 87 ExceptionsType = ExceptionHandling::None; 88 WinEHEncodingType = WinEH::EncodingType::Invalid; 89 DwarfUsesRelocationsAcrossSections = true; 90 DwarfFDESymbolsUseAbsDiff = false; 91 DwarfRegNumForCFI = false; 92 NeedsDwarfSectionOffsetDirective = false; 93 UseParensForSymbolVariant = false; 94 UseLogicalShr = true; 95 96 // FIXME: Clang's logic should be synced with the logic used to initialize 97 // this member and the two implementations should be merged. 98 // For reference: 99 // - Solaris always enables the integrated assembler by default 100 // - SparcELFMCAsmInfo and X86ELFMCAsmInfo are handling this case 101 // - Windows always enables the integrated assembler by default 102 // - MCAsmInfoCOFF is handling this case, should it be MCAsmInfoMicrosoft? 103 // - MachO targets always enables the integrated assembler by default 104 // - MCAsmInfoDarwin is handling this case 105 // - Generic_GCC toolchains enable the integrated assembler on a per 106 // architecture basis. 107 // - The target subclasses for AArch64, ARM, and X86 handle these cases 108 UseIntegratedAssembler = false; 109 110 CompressDebugSections = false; 111 } 112 113 MCAsmInfo::~MCAsmInfo() { 114 } 115 116 bool MCAsmInfo::isSectionAtomizableBySymbols(const MCSection &Section) const { 117 return false; 118 } 119 120 const MCExpr * 121 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym, 122 unsigned Encoding, 123 MCStreamer &Streamer) const { 124 return getExprForFDESymbol(Sym, Encoding, Streamer); 125 } 126 127 const MCExpr * 128 MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym, 129 unsigned Encoding, 130 MCStreamer &Streamer) const { 131 if (!(Encoding & dwarf::DW_EH_PE_pcrel)) 132 return MCSymbolRefExpr::create(Sym, Streamer.getContext()); 133 134 MCContext &Context = Streamer.getContext(); 135 const MCExpr *Res = MCSymbolRefExpr::create(Sym, Context); 136 MCSymbol *PCSym = Context.createTempSymbol(); 137 Streamer.EmitLabel(PCSym); 138 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, Context); 139 return MCBinaryExpr::createSub(Res, PC, Context); 140 } 141 142 static bool isAcceptableChar(char C) { 143 return (C >= 'a' && C <= 'z') || (C >= 'A' && C <= 'Z') || 144 (C >= '0' && C <= '9') || C == '_' || C == '$' || C == '.' || C == '@'; 145 } 146 147 bool MCAsmInfo::isValidUnquotedName(StringRef Name) const { 148 if (Name.empty()) 149 return false; 150 151 // If any of the characters in the string is an unacceptable character, force 152 // quotes. 153 for (char C : Name) { 154 if (!isAcceptableChar(C)) 155 return false; 156 } 157 158 return true; 159 } 160 161 bool MCAsmInfo::shouldOmitSectionDirective(StringRef SectionName) const { 162 // FIXME: Does .section .bss/.data/.text work everywhere?? 163 return SectionName == ".text" || SectionName == ".data" || 164 (SectionName == ".bss" && !usesELFSectionDirectiveForBSS()); 165 } 166
