1//===-- X86MCAsmInfo.cpp - X86 asm properties -----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains the declarations of the X86MCAsmInfo properties.
10//
11//===----------------------------------------------------------------------===//
12
13#include "X86MCAsmInfo.h"
14#include "llvm/MC/MCExpr.h"
15#include "llvm/MC/MCStreamer.h"
16#include "llvm/Support/CommandLine.h"
17#include "llvm/TargetParser/Triple.h"
18using namespace llvm;
19
20enum AsmWriterFlavorTy {
21 // Note: This numbering has to match the GCC assembler dialects for inline
22 // asm alternatives to work right.
23 ATT = 0, Intel = 1
24};
25
26static cl::opt<AsmWriterFlavorTy> AsmWriterFlavor(
27 "x86-asm-syntax", cl::init(Val: ATT), cl::Hidden,
28 cl::desc("Choose style of code to emit from X86 backend:"),
29 cl::values(clEnumValN(ATT, "att", "Emit AT&T-style assembly"),
30 clEnumValN(Intel, "intel", "Emit Intel-style assembly")));
31
32static cl::opt<bool>
33MarkedJTDataRegions("mark-data-regions", cl::init(Val: true),
34 cl::desc("Mark code section jump table data regions."),
35 cl::Hidden);
36
37void X86MCAsmInfoDarwin::anchor() { }
38
39X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
40 bool is64Bit = T.getArch() == Triple::x86_64;
41 if (is64Bit)
42 CodePointerSize = CalleeSaveStackSlotSize = 8;
43
44 AssemblerDialect = AsmWriterFlavor;
45
46 TextAlignFillValue = 0x90;
47
48 if (!is64Bit)
49 Data64bitsDirective = nullptr; // we can't emit a 64-bit unit
50
51 // Use ## as a comment string so that .s files generated by llvm can go
52 // through the GCC preprocessor without causing an error. This is needed
53 // because "clang foo.s" runs the C preprocessor, which is usually reserved
54 // for .S files on other systems. Perhaps this is because the file system
55 // wasn't always case preserving or something.
56 CommentString = "##";
57
58 SupportsDebugInformation = true;
59 UseDataRegionDirectives = MarkedJTDataRegions;
60
61 // Exceptions handling
62 ExceptionsType = ExceptionHandling::DwarfCFI;
63
64 // old assembler lacks some directives
65 // FIXME: this should really be a check on the assembler characteristics
66 // rather than OS version
67 if (T.isMacOSX() && T.isMacOSXVersionLT(Major: 10, Minor: 6))
68 HasWeakDefCanBeHiddenDirective = false;
69
70 // Assume ld64 is new enough that the abs-ified FDE relocs may be used
71 // (actually, must, since otherwise the non-extern relocations we produce
72 // overwhelm ld64's tiny little mind and it fails).
73 DwarfFDESymbolsUseAbsDiff = true;
74}
75
76X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple)
77 : X86MCAsmInfoDarwin(Triple) {
78}
79
80void X86ELFMCAsmInfo::anchor() { }
81
82X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
83 bool is64Bit = T.getArch() == Triple::x86_64;
84 bool isX32 = T.isX32();
85
86 // For ELF, x86-64 pointer size depends on the ABI.
87 // For x86-64 without the x32 ABI, pointer size is 8. For x86 and for x86-64
88 // with the x32 ABI, pointer size remains the default 4.
89 CodePointerSize = (is64Bit && !isX32) ? 8 : 4;
90
91 // OTOH, stack slot size is always 8 for x86-64, even with the x32 ABI.
92 CalleeSaveStackSlotSize = is64Bit ? 8 : 4;
93
94 AssemblerDialect = AsmWriterFlavor;
95
96 TextAlignFillValue = 0x90;
97
98 // Debug Information
99 SupportsDebugInformation = true;
100
101 // Exceptions handling
102 ExceptionsType = ExceptionHandling::DwarfCFI;
103}
104
105const MCExpr *
106X86_64MCAsmInfoDarwin::getExprForPersonalitySymbol(const MCSymbol *Sym,
107 unsigned Encoding,
108 MCStreamer &Streamer) const {
109 MCContext &Context = Streamer.getContext();
110 const MCExpr *Res =
111 MCSymbolRefExpr::create(Symbol: Sym, Kind: MCSymbolRefExpr::VK_GOTPCREL, Ctx&: Context);
112 const MCExpr *Four = MCConstantExpr::create(Value: 4, Ctx&: Context);
113 return MCBinaryExpr::createAdd(LHS: Res, RHS: Four, Ctx&: Context);
114}
115
116void X86MCAsmInfoMicrosoft::anchor() { }
117
118X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
119 if (Triple.getArch() == Triple::x86_64) {
120 PrivateGlobalPrefix = ".L";
121 PrivateLabelPrefix = ".L";
122 CodePointerSize = 8;
123 WinEHEncodingType = WinEH::EncodingType::Itanium;
124 } else {
125 // 32-bit X86 doesn't use CFI, so this isn't a real encoding type. It's just
126 // a place holder that the Windows EHStreamer looks for to suppress CFI
127 // output. In particular, usesWindowsCFI() returns false.
128 WinEHEncodingType = WinEH::EncodingType::X86;
129 }
130
131 ExceptionsType = ExceptionHandling::WinEH;
132
133 AssemblerDialect = AsmWriterFlavor;
134
135 TextAlignFillValue = 0x90;
136
137 AllowAtInName = true;
138}
139
140void X86MCAsmInfoMicrosoftMASM::anchor() { }
141
142X86MCAsmInfoMicrosoftMASM::X86MCAsmInfoMicrosoftMASM(const Triple &Triple)
143 : X86MCAsmInfoMicrosoft(Triple) {
144 DollarIsPC = true;
145 SeparatorString = "\n";
146 CommentString = ";";
147 AllowAdditionalComments = false;
148 AllowQuestionAtStartOfIdentifier = true;
149 AllowDollarAtStartOfIdentifier = true;
150 AllowAtAtStartOfIdentifier = true;
151}
152
153void X86MCAsmInfoGNUCOFF::anchor() { }
154
155X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple) {
156 assert((Triple.isOSWindows() || Triple.isUEFI()) &&
157 "Windows and UEFI are the only supported COFF targets");
158 if (Triple.getArch() == Triple::x86_64) {
159 PrivateGlobalPrefix = ".L";
160 PrivateLabelPrefix = ".L";
161 CodePointerSize = 8;
162 WinEHEncodingType = WinEH::EncodingType::Itanium;
163 ExceptionsType = ExceptionHandling::WinEH;
164 } else {
165 ExceptionsType = ExceptionHandling::DwarfCFI;
166 }
167
168 AssemblerDialect = AsmWriterFlavor;
169
170 TextAlignFillValue = 0x90;
171
172 AllowAtInName = true;
173}
174