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 #include "llvm/Support/ELF.h"
  21 using namespace llvm;
  22
  23 enum AsmWriterFlavorTy {
  24   // Note: This numbering has to match the GCC assembler dialects for inline
  25   // asm alternatives to work right.
  26   ATT = 0, Intel = 1
  27 };
  28
  29 static cl::opt<AsmWriterFlavorTy>
  30 AsmWriterFlavor("x86-asm-syntax", cl::init(ATT),
  31   cl::desc("Choose style of code to emit from X86 backend:"),
  32   cl::values(clEnumValN(ATT,   "att",   "Emit AT&T-style assembly"),
  33              clEnumValN(Intel, "intel", "Emit Intel-style assembly"),
  34              clEnumValEnd));
  35
  36
  37 static const char *const x86_asm_table[] = {
  38   "{si}", "S",
  39   "{di}", "D",
  40   "{ax}", "a",
  41   "{cx}", "c",
  42   "{memory}", "memory",
  43   "{flags}", "",
  44   "{dirflag}", "",
  45   "{fpsr}", "",
  46   "{cc}", "cc",
  47   0,0};
  48
  49 X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &Triple) {
  50   AsmTransCBE = x86_asm_table;
  51   AssemblerDialect = AsmWriterFlavor;
  52
  53   bool is64Bit = Triple.getArch() == Triple::x86_64;
  54
  55   TextAlignFillValue = 0x90;
  56
  57   if (!is64Bit)
  58     Data64bitsDirective = 0;       // we can't emit a 64-bit unit
  59
  60   // Use ## as a comment string so that .s files generated by llvm can go
  61   // through the GCC preprocessor without causing an error.  This is needed
  62   // because "clang foo.s" runs the C preprocessor, which is usually reserved
  63   // for .S files on other systems.  Perhaps this is because the file system
  64   // wasn't always case preserving or something.
  65   CommentString = "##";
  66   PCSymbol = ".";
  67
  68   SupportsDebugInformation = true;
  69   DwarfUsesInlineInfoSection = true;
  70
  71   // Exceptions handling
  72   ExceptionsType = ExceptionHandling::DwarfTable;
  73 }
  74
  75 X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
  76   AsmTransCBE = x86_asm_table;
  77   AssemblerDialect = AsmWriterFlavor;
  78
  79   TextAlignFillValue = 0x90;
  80
  81   PrivateGlobalPrefix = ".L";
  82   WeakRefDirective = "\t.weak\t";
  83   PCSymbol = ".";
  84
  85   // Set up DWARF directives
  86   HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
  87
  88   // Debug Information
  89   SupportsDebugInformation = true;
  90
  91   // Exceptions handling
  92   ExceptionsType = ExceptionHandling::DwarfTable;
  93
  94   // OpenBSD has buggy support for .quad in 32-bit mode, just split into two
  95   // .words.
  96   if (T.getOS() == Triple::OpenBSD && T.getArch() == Triple::x86)
  97     Data64bitsDirective = 0;
  98 }
  99
 100 const MCSection *X86ELFMCAsmInfo::
 101 getNonexecutableStackSection(MCContext &Ctx) const {
 102   return Ctx.getELFSection(".note.GNU-stack", ELF::SHT_PROGBITS,
 103                            0, SectionKind::getMetadata());
 104 }
 105
 106 X86MCAsmInfoCOFF::X86MCAsmInfoCOFF(const Triple &Triple) {
 107   if (Triple.getArch() == Triple::x86_64) {
 108     GlobalPrefix = "";
 109     PrivateGlobalPrefix = ".L";
 110   }
 111
 112   AsmTransCBE = x86_asm_table;
 113   AssemblerDialect = AsmWriterFlavor;
 114
 115   TextAlignFillValue = 0x90;
 116 }