X86MCAsmInfo.cpp

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//===-- X86MCAsmInfo.cpp - X86 asm properties -----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the declarations of the X86MCAsmInfo properties.
//
//===----------------------------------------------------------------------===//
 
#include "X86MCAsmInfo.h"
#include "llvm/ADT/Enum.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/TargetParser/Triple.h"
using namespace llvm;
 
enum AsmWriterFlavorTy {
  // Note: This numbering has to match the GCC assembler dialects for inline
  // asm alternatives to work right.
  ATT = 0, Intel = 1
};
 
static cl::opt<AsmWriterFlavorTy> X86AsmSyntax(
    "x86-asm-syntax", cl::init(ATT), cl::Hidden,
    cl::desc("Select the assembly style for input"),
    cl::values(clEnumValN(ATT, "att", "Emit AT&T-style assembly"),
               clEnumValN(Intel, "intel", "Emit Intel-style assembly")));
 
static cl::opt<bool>
MarkedJTDataRegions("mark-data-regions", cl::init(true),
  cl::desc("Mark code section jump table data regions."),
  cl::Hidden);
 
constexpr EnumStringDef<MCAsmInfo::AtSpecifierKind> AtSpecifierDefs[] = {
    {{"ABS8"}, X86::S_ABS8},
    {{"DTPOFF"}, X86::S_DTPOFF},
    {{"DTPREL"}, X86::S_DTPREL},
    {{"GOT"}, X86::S_GOT},
    {{"GOTENT"}, X86::S_GOTENT},
    {{"GOTNTPOFF"}, X86::S_GOTNTPOFF},
    {{"GOTOFF"}, X86::S_GOTOFF},
    {{"GOTPCREL"}, X86::S_GOTPCREL},
    {{"GOTPCREL_NORELAX"}, X86::S_GOTPCREL_NORELAX},
    {{"GOTREL"}, X86::S_GOTREL},
    {{"GOTTPOFF"}, X86::S_GOTTPOFF},
    {{"INDNTPOFF"}, X86::S_INDNTPOFF},
    {{"IMGREL"}, MCSymbolRefExpr::VK_COFF_IMGREL32},
    {{"NTPOFF"}, X86::S_NTPOFF},
    {{"PCREL"}, X86::S_PCREL},
    {{"PLT"}, X86::S_PLT},
    {{"PLTOFF"}, X86::S_PLTOFF},
    {{"SECREL32"}, X86::S_COFF_SECREL},
    {{"SIZE"}, X86::S_SIZE},
    {{"tlscall"}, X86::S_TLSCALL},
    {{"tlsdesc"}, X86::S_TLSDESC},
    {{"TLSGD"}, X86::S_TLSGD},
    {{"TLSLD"}, X86::S_TLSLD},
    {{"TLSLDM"}, X86::S_TLSLDM},
    {{"TLVP"}, X86::S_TLVP},
    {{"TLVPPAGE"}, X86::S_TLVPPAGE},
    {{"TLVPPAGEOFF"}, X86::S_TLVPPAGEOFF},
    {{"TPOFF"}, X86::S_TPOFF},
};
constexpr auto atSpecifiers = BUILD_ENUM_STRINGS(AtSpecifierDefs);
 
void X86MCAsmInfoDarwin::anchor() { }
 
X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T,
                                       const MCTargetOptions &Options)
    : MCAsmInfoDarwin(Options) {
  bool is64Bit = T.isX86_64();
  if (is64Bit)
    CodePointerSize = CalleeSaveStackSlotSize = 8;
 
  AssemblerDialect = X86AsmSyntax;
 
  if (!is64Bit)
    Data64bitsDirective = nullptr;       // we can't emit a 64-bit unit
 
  // Use ## as a comment string so that .s files generated by llvm can go
  // through the GCC preprocessor without causing an error.  This is needed
  // because "clang foo.s" runs the C preprocessor, which is usually reserved
  // for .S files on other systems.  Perhaps this is because the file system
  // wasn't always case preserving or something.
  CommentString = "##";
 
  SupportsDebugInformation = true;
  UseDataRegionDirectives = MarkedJTDataRegions;
 
  // Exceptions handling
  ExceptionsType = ExceptionHandling::DwarfCFI;
 
  // old assembler lacks some directives
  // FIXME: this should really be a check on the assembler characteristics
  // rather than OS version
  if (T.isMacOSX() && T.isMacOSXVersionLT(10, 6))
    HasWeakDefCanBeHiddenDirective = false;
 
  // Assume ld64 is new enough that the abs-ified FDE relocs may be used
  // (actually, must, since otherwise the non-extern relocations we produce
  // overwhelm ld64's tiny little mind and it fails).
  DwarfFDESymbolsUseAbsDiff = true;
 
  initializeAtSpecifiers(atSpecifiers);
}
 
X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple,
                                             const MCTargetOptions &Options)
    : X86MCAsmInfoDarwin(Triple, Options) {}
 
void X86ELFMCAsmInfo::anchor() { }
 
X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T,
                                 const MCTargetOptions &Options)
    : MCAsmInfoELF(Options) {
  bool is64Bit = T.isX86_64();
  bool isX32 = T.isX32();
 
  // For ELF, x86-64 pointer size depends on the ABI.
  // For x86-64 without the x32 ABI, pointer size is 8. For x86 and for x86-64
  // with the x32 ABI, pointer size remains the default 4.
  CodePointerSize = (is64Bit && !isX32) ? 8 : 4;
 
  // OTOH, stack slot size is always 8 for x86-64, even with the x32 ABI.
  CalleeSaveStackSlotSize = is64Bit ? 8 : 4;
 
  AssemblerDialect = X86AsmSyntax;
 
  // Debug Information
  SupportsDebugInformation = true;
 
  // Exceptions handling
  ExceptionsType = ExceptionHandling::DwarfCFI;
 
  initializeAtSpecifiers(atSpecifiers);
}
 
const MCExpr *
X86_64MCAsmInfoDarwin::getExprForPersonalitySymbol(const MCSymbol *Sym,
                                                   unsigned Encoding,
                                                   MCStreamer &Streamer) const {
  MCContext &Context = Streamer.getContext();
  const MCExpr *Res = MCSymbolRefExpr::create(Sym, X86::S_GOTPCREL, Context);
  const MCExpr *Four = MCConstantExpr::create(4, Context);
  return MCBinaryExpr::createAdd(Res, Four, Context);
}
 
void X86MCAsmInfoMicrosoft::anchor() { }
 
X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple,
                                             const MCTargetOptions &Options)
    : MCAsmInfoMicrosoft(Options) {
  if (Triple.isX86_64()) {
    InternalSymbolPrefix = ".L";
    CodePointerSize = 8;
    WinEHEncodingType = WinEH::EncodingType::Itanium;
  } else {
    // 32-bit X86 doesn't use CFI, so this isn't a real encoding type. It's just
    // a place holder that the Windows EHStreamer looks for to suppress CFI
    // output. In particular, usesWindowsCFI() returns false.
    WinEHEncodingType = WinEH::EncodingType::X86;
  }
 
  ExceptionsType = ExceptionHandling::WinEH;
 
  AssemblerDialect = X86AsmSyntax;
 
  AllowAtInName = true;
 
  initializeAtSpecifiers(atSpecifiers);
}
 
void X86MCAsmInfoMicrosoftMASM::anchor() { }
 
X86MCAsmInfoMicrosoftMASM::X86MCAsmInfoMicrosoftMASM(
    const Triple &Triple, const MCTargetOptions &Options)
    : X86MCAsmInfoMicrosoft(Triple, Options) {
  DollarIsPC = true;
  SeparatorString = "\n";
  CommentString = ";";
  AllowAdditionalComments = false;
  AllowQuestionAtStartOfIdentifier = true;
  AllowDollarAtStartOfIdentifier = true;
  AllowAtAtStartOfIdentifier = true;
}
 
void X86MCAsmInfoGNUCOFF::anchor() { }
 
X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple,
                                         const MCTargetOptions &Options)
    : MCAsmInfoGNUCOFF(Options) {
  assert(Triple.isOSWindowsOrUEFI() &&
         "Windows and UEFI are the only supported COFF targets");
  if (Triple.isX86_64()) {
    InternalSymbolPrefix = ".L";
    CodePointerSize = 8;
    WinEHEncodingType = WinEH::EncodingType::Itanium;
    ExceptionsType = ExceptionHandling::WinEH;
  } else {
    ExceptionsType = ExceptionHandling::DwarfCFI;
  }
 
  AssemblerDialect = X86AsmSyntax;
 
  AllowAtInName = true;
 
  initializeAtSpecifiers(atSpecifiers);
}