lib/Target/X86/X86MCAsmInfo.cpp

   1 //===-- X86MCAsmInfo.cpp - X86 asm properties -----------------------------===//
   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 contains the declarations of the X86MCAsmInfo properties.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "X86MCAsmInfo.h"
  15 #include "X86TargetMachine.h"
  16 #include "llvm/ADT/Triple.h"
  17 #include "llvm/MC/MCContext.h"
  18 #include "llvm/MC/MCSectionELF.h"
  19 #include "llvm/Support/CommandLine.h"
  20 using namespace llvm;
  21
  22 enum AsmWriterFlavorTy {
  23   // Note: This numbering has to match the GCC assembler dialects for inline
  24   // asm alternatives to work right.
  25   ATT = 0, Intel = 1
  26 };
  27
  28 static cl::opt<AsmWriterFlavorTy>
  29 AsmWriterFlavor("x86-asm-syntax", cl::init(ATT),
  30   cl::desc("Choose style of code to emit from X86 backend:"),
  31   cl::values(clEnumValN(ATT,   "att",   "Emit AT&T-style assembly"),
  32              clEnumValN(Intel, "intel", "Emit Intel-style assembly"),
  33              clEnumValEnd));
  34
  35
  36 static const char *const x86_asm_table[] = {
  37   "{si}", "S",
  38   "{di}", "D",
  39   "{ax}", "a",
  40   "{cx}", "c",
  41   "{memory}", "memory",
  42   "{flags}", "",
  43   "{dirflag}", "",
  44   "{fpsr}", "",
  45   "{cc}", "cc",
  46   0,0};
  47
  48 X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &Triple) {
  49   AsmTransCBE = x86_asm_table;
  50   AssemblerDialect = AsmWriterFlavor;
  51
  52   bool is64Bit = Triple.getArch() == Triple::x86_64;
  53
  54   TextAlignFillValue = 0x90;
  55
  56   if (!is64Bit)
  57     Data64bitsDirective = 0;       // we can't emit a 64-bit unit
  58
  59   // Use ## as a comment string so that .s files generated by llvm can go
  60   // through the GCC preprocessor without causing an error.  This is needed
  61   // because "clang foo.s" runs the C preprocessor, which is usually reserved
  62   // for .S files on other systems.  Perhaps this is because the file system
  63   // wasn't always case preserving or something.
  64   CommentString = "##";
  65   PCSymbol = ".";
  66
  67   SupportsDebugInformation = true;
  68   DwarfUsesInlineInfoSection = true;
  69
  70   // Exceptions handling
  71   ExceptionsType = ExceptionHandling::Dwarf;
  72 }
  73
  74 X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
  75   AsmTransCBE = x86_asm_table;
  76   AssemblerDialect = AsmWriterFlavor;
  77
  78   TextAlignFillValue = 0x90;
  79
  80   PrivateGlobalPrefix = ".L";
  81   WeakRefDirective = "\t.weak\t";
  82   PCSymbol = ".";
  83
  84   // Set up DWARF directives
  85   HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
  86
  87   // Debug Information
  88   SupportsDebugInformation = true;
  89
  90   // Exceptions handling
  91   ExceptionsType = ExceptionHandling::Dwarf;
  92
  93   // OpenBSD has buggy support for .quad in 32-bit mode, just split into two
  94   // .words.
  95   if (T.getOS() == Triple::OpenBSD && T.getArch() == Triple::x86)
  96     Data64bitsDirective = 0;
  97 }
  98
  99 const MCSection *X86ELFMCAsmInfo::
 100 getNonexecutableStackSection(MCContext &Ctx) const {
 101   return Ctx.getELFSection(".note.GNU-stack", MCSectionELF::SHT_PROGBITS,
 102                            0, SectionKind::getMetadata(), false);
 103 }
 104
 105 X86MCAsmInfoCOFF::X86MCAsmInfoCOFF(const Triple &Triple) {
 106   if (Triple.getArch() == Triple::x86_64)
 107     GlobalPrefix = "";
 108
 109   AsmTransCBE = x86_asm_table;
 110   AssemblerDialect = AsmWriterFlavor;
 111
 112   TextAlignFillValue = 0x90;
 113 }