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 "llvm/ADT/Triple.h"
16#include "llvm/MC/MCContext.h"
17#include "llvm/MC/MCExpr.h"
18#include "llvm/MC/MCSectionELF.h"
19#include "llvm/MC/MCStreamer.h"
20#include "llvm/Support/CommandLine.h"
21#include "llvm/Support/ELF.h"
22using namespace llvm;
23
24enum AsmWriterFlavorTy {
25  // Note: This numbering has to match the GCC assembler dialects for inline
26  // asm alternatives to work right.
27  ATT = 0, Intel = 1
28};
29
30static cl::opt<AsmWriterFlavorTy>
31AsmWriterFlavor("x86-asm-syntax", cl::init(ATT),
32  cl::desc("Choose style of code to emit from X86 backend:"),
33  cl::values(clEnumValN(ATT,   "att",   "Emit AT&T-style assembly"),
34             clEnumValN(Intel, "intel", "Emit Intel-style assembly"),
35             clEnumValEnd));
36
37
38void X86MCAsmInfoDarwin::anchor() { }
39
40X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
41  bool is64Bit = T.getArch() == Triple::x86_64;
42  if (is64Bit)
43    PointerSize = 8;
44
45  AssemblerDialect = AsmWriterFlavor;
46
47  TextAlignFillValue = 0x90;
48
49  if (!is64Bit)
50    Data64bitsDirective = 0;       // we can't emit a 64-bit unit
51
52  // Use ## as a comment string so that .s files generated by llvm can go
53  // through the GCC preprocessor without causing an error.  This is needed
54  // because "clang foo.s" runs the C preprocessor, which is usually reserved
55  // for .S files on other systems.  Perhaps this is because the file system
56  // wasn't always case preserving or something.
57  CommentString = "##";
58  PCSymbol = ".";
59
60  SupportsDebugInformation = true;
61  DwarfUsesInlineInfoSection = true;
62
63  // Exceptions handling
64  ExceptionsType = ExceptionHandling::DwarfCFI;
65}
66
67X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple)
68  : X86MCAsmInfoDarwin(Triple) {
69}
70
71void X86ELFMCAsmInfo::anchor() { }
72
73X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
74  if (T.getArch() == Triple::x86_64)
75    PointerSize = 8;
76
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::DwarfCFI;
93
94  // OpenBSD and Bitrig have buggy support for .quad in 32-bit mode, just split
95  // into two .words.
96  if ((T.getOS() == Triple::OpenBSD || T.getOS() == Triple::Bitrig) &&
97       T.getArch() == Triple::x86)
98    Data64bitsDirective = 0;
99}
100
101const MCExpr *
102X86_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
112const MCSection *X86ELFMCAsmInfo::
113getNonexecutableStackSection(MCContext &Ctx) const {
114  return Ctx.getELFSection(".note.GNU-stack", ELF::SHT_PROGBITS,
115                           0, SectionKind::getMetadata());
116}
117
118void X86MCAsmInfoMicrosoft::anchor() { }
119
120X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
121  if (Triple.getArch() == Triple::x86_64) {
122    GlobalPrefix = "";
123    PrivateGlobalPrefix = ".L";
124  }
125
126  AssemblerDialect = AsmWriterFlavor;
127
128  TextAlignFillValue = 0x90;
129}
130
131void X86MCAsmInfoGNUCOFF::anchor() { }
132
133X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple) {
134  if (Triple.getArch() == Triple::x86_64) {
135    GlobalPrefix = "";
136    PrivateGlobalPrefix = ".L";
137  }
138
139  AssemblerDialect = AsmWriterFlavor;
140
141  TextAlignFillValue = 0x90;
142
143  // Exceptions handling
144  ExceptionsType = ExceptionHandling::DwarfCFI;
145}
146