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"
22 using namespace llvm;
23
24 enum 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
30 static cl::opt<AsmWriterFlavorTy>
31 AsmWriterFlavor("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
anchor()38 void X86MCAsmInfoDarwin::anchor() { }
39
X86MCAsmInfoDarwin(const Triple & T)40 X86MCAsmInfoDarwin::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
X86_64MCAsmInfoDarwin(const Triple & Triple)67 X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple)
68 : X86MCAsmInfoDarwin(Triple) {
69 }
70
anchor()71 void X86ELFMCAsmInfo::anchor() { }
72
X86ELFMCAsmInfo(const Triple & T)73 X86ELFMCAsmInfo::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
101 const MCExpr *
getExprForPersonalitySymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const102 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 const MCSection *X86ELFMCAsmInfo::
getNonexecutableStackSection(MCContext & Ctx) const113 getNonexecutableStackSection(MCContext &Ctx) const {
114 return Ctx.getELFSection(".note.GNU-stack", ELF::SHT_PROGBITS,
115 0, SectionKind::getMetadata());
116 }
117
anchor()118 void X86MCAsmInfoMicrosoft::anchor() { }
119
X86MCAsmInfoMicrosoft(const Triple & Triple)120 X86MCAsmInfoMicrosoft::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
anchor()131 void X86MCAsmInfoGNUCOFF::anchor() { }
132
X86MCAsmInfoGNUCOFF(const Triple & Triple)133 X86MCAsmInfoGNUCOFF::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