llvm/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp

   1 //===-- X86MCAsmInfo.cpp - X86 asm properties -----------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains the declarations of the X86MCAsmInfo properties.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "X86MCAsmInfo.h"
  14 #include "llvm/MC/MCExpr.h"
  15 #include "llvm/MC/MCStreamer.h"
  16 #include "llvm/Support/CommandLine.h"
  17 #include "llvm/TargetParser/Triple.h"
  18 using namespace llvm;
  19
  20 enum AsmWriterFlavorTy {
  21   // Note: This numbering has to match the GCC assembler dialects for inline
  22   // asm alternatives to work right.
  23   ATT = 0, Intel = 1
  24 };
  25
  26 static cl::opt<AsmWriterFlavorTy> X86AsmSyntax(
  27     "x86-asm-syntax", cl::init(ATT), cl::Hidden,
  28     cl::desc("Select the assembly style for input"),
  29     cl::values(clEnumValN(ATT, "att", "Emit AT&T-style assembly"),
  30                clEnumValN(Intel, "intel", "Emit Intel-style assembly")));
  31
  32 static cl::opt<bool>
  33 MarkedJTDataRegions("mark-data-regions", cl::init(true),
  34   cl::desc("Mark code section jump table data regions."),
  35   cl::Hidden);
  36
  37 void X86MCAsmInfoDarwin::anchor() { }
  38
  39 X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
  40   bool is64Bit = T.getArch() == Triple::x86_64;
  41   if (is64Bit)
  42     CodePointerSize = CalleeSaveStackSlotSize = 8;
  43
  44   AssemblerDialect = X86AsmSyntax;
  45
  46   if (!is64Bit)
  47     Data64bitsDirective = nullptr;       // we can't emit a 64-bit unit
  48
  49   // Use ## as a comment string so that .s files generated by llvm can go
  50   // through the GCC preprocessor without causing an error.  This is needed
  51   // because "clang foo.s" runs the C preprocessor, which is usually reserved
  52   // for .S files on other systems.  Perhaps this is because the file system
  53   // wasn't always case preserving or something.
  54   CommentString = "##";
  55
  56   SupportsDebugInformation = true;
  57   UseDataRegionDirectives = MarkedJTDataRegions;
  58
  59   // Exceptions handling
  60   ExceptionsType = ExceptionHandling::DwarfCFI;
  61
  62   // old assembler lacks some directives
  63   // FIXME: this should really be a check on the assembler characteristics
  64   // rather than OS version
  65   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 6))
  66     HasWeakDefCanBeHiddenDirective = false;
  67
  68   // Assume ld64 is new enough that the abs-ified FDE relocs may be used
  69   // (actually, must, since otherwise the non-extern relocations we produce
  70   // overwhelm ld64's tiny little mind and it fails).
  71   DwarfFDESymbolsUseAbsDiff = true;
  72 }
  73
  74 X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple)
  75   : X86MCAsmInfoDarwin(Triple) {
  76 }
  77
  78 void X86ELFMCAsmInfo::anchor() { }
  79
  80 X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
  81   bool is64Bit = T.getArch() == Triple::x86_64;
  82   bool isX32 = T.isX32();
  83
  84   // For ELF, x86-64 pointer size depends on the ABI.
  85   // For x86-64 without the x32 ABI, pointer size is 8. For x86 and for x86-64
  86   // with the x32 ABI, pointer size remains the default 4.
  87   CodePointerSize = (is64Bit && !isX32) ? 8 : 4;
  88
  89   // OTOH, stack slot size is always 8 for x86-64, even with the x32 ABI.
  90   CalleeSaveStackSlotSize = is64Bit ? 8 : 4;
  91
  92   AssemblerDialect = X86AsmSyntax;
  93
  94   // Debug Information
  95   SupportsDebugInformation = true;
  96
  97   // Exceptions handling
  98   ExceptionsType = ExceptionHandling::DwarfCFI;
  99 }
 100
 101 const MCExpr *
 102 X86_64MCAsmInfoDarwin::getExprForPersonalitySymbol(const MCSymbol *Sym,
 103                                                    unsigned Encoding,
 104                                                    MCStreamer &Streamer) const {
 105   MCContext &Context = Streamer.getContext();
 106   const MCExpr *Res =
 107     MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOTPCREL, Context);
 108   const MCExpr *Four = MCConstantExpr::create(4, Context);
 109   return MCBinaryExpr::createAdd(Res, Four, Context);
 110 }
 111
 112 void X86MCAsmInfoMicrosoft::anchor() { }
 113
 114 X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
 115   if (Triple.getArch() == Triple::x86_64) {
 116     PrivateGlobalPrefix = ".L";
 117     PrivateLabelPrefix = ".L";
 118     CodePointerSize = 8;
 119     WinEHEncodingType = WinEH::EncodingType::Itanium;
 120   } else {
 121     // 32-bit X86 doesn't use CFI, so this isn't a real encoding type. It's just
 122     // a place holder that the Windows EHStreamer looks for to suppress CFI
 123     // output. In particular, usesWindowsCFI() returns false.
 124     WinEHEncodingType = WinEH::EncodingType::X86;
 125   }
 126
 127   ExceptionsType = ExceptionHandling::WinEH;
 128
 129   AssemblerDialect = X86AsmSyntax;
 130
 131   AllowAtInName = true;
 132 }
 133
 134 void X86MCAsmInfoMicrosoftMASM::anchor() { }
 135
 136 X86MCAsmInfoMicrosoftMASM::X86MCAsmInfoMicrosoftMASM(const Triple &Triple)
 137     : X86MCAsmInfoMicrosoft(Triple) {
 138   DollarIsPC = true;
 139   SeparatorString = "\n";
 140   CommentString = ";";
 141   AllowAdditionalComments = false;
 142   AllowQuestionAtStartOfIdentifier = true;
 143   AllowDollarAtStartOfIdentifier = true;
 144   AllowAtAtStartOfIdentifier = true;
 145 }
 146
 147 void X86MCAsmInfoGNUCOFF::anchor() { }
 148
 149 X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple) {
 150   assert((Triple.isOSWindows() || Triple.isUEFI()) &&
 151          "Windows and UEFI are the only supported COFF targets");
 152   if (Triple.getArch() == Triple::x86_64) {
 153     PrivateGlobalPrefix = ".L";
 154     PrivateLabelPrefix = ".L";
 155     CodePointerSize = 8;
 156     WinEHEncodingType = WinEH::EncodingType::Itanium;
 157     ExceptionsType = ExceptionHandling::WinEH;
 158   } else {
 159     ExceptionsType = ExceptionHandling::DwarfCFI;
 160   }
 161
 162   AssemblerDialect = X86AsmSyntax;
 163
 164   AllowAtInName = true;
 165 }