MCAsmInfo.cpp revision cd81d94322a39503e4a3e87b6ee03d4fcb3465fb 
1//===-- MCAsmInfo.cpp - Asm Info -------------------------------------------==//
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 defines target asm properties related what form asm statements
11// should take.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/MC/MCAsmInfo.h"
16#include "llvm/MC/MCContext.h"
17#include "llvm/MC/MCExpr.h"
18#include "llvm/MC/MCStreamer.h"
19#include "llvm/Support/DataTypes.h"
20#include "llvm/Support/Dwarf.h"
21#include <cctype>
22#include <cstring>
23using namespace llvm;
24
25MCAsmInfo::MCAsmInfo() {
26  PointerSize = 4;
27  CalleeSaveStackSlotSize = 4;
28
29  IsLittleEndian = true;
30  StackGrowsUp = false;
31  HasSubsectionsViaSymbols = false;
32  HasMachoZeroFillDirective = false;
33  HasMachoTBSSDirective = false;
34  HasStaticCtorDtorReferenceInStaticMode = false;
35  LinkerRequiresNonEmptyDwarfLines = false;
36  MaxInstLength = 4;
37  MinInstAlignment = 1;
38  DollarIsPC = false;
39  SeparatorString = ";";
40  CommentString = "#";
41  LabelSuffix = ":";
42  UseAssignmentForEHBegin = false;
43  PrivateGlobalPrefix = "L";
44  LinkerPrivateGlobalPrefix = "";
45  InlineAsmStart = "APP";
46  InlineAsmEnd = "NO_APP";
47  Code16Directive = ".code16";
48  Code32Directive = ".code32";
49  Code64Directive = ".code64";
50  AssemblerDialect = 0;
51  AllowAtInName = false;
52  UseDataRegionDirectives = false;
53  ZeroDirective = "\t.zero\t";
54  AsciiDirective = "\t.ascii\t";
55  AscizDirective = "\t.asciz\t";
56  Data8bitsDirective = "\t.byte\t";
57  Data16bitsDirective = "\t.short\t";
58  Data32bitsDirective = "\t.long\t";
59  Data64bitsDirective = "\t.quad\t";
60  SunStyleELFSectionSwitchSyntax = false;
61  UsesELFSectionDirectiveForBSS = false;
62  AlignmentIsInBytes = true;
63  TextAlignFillValue = 0;
64  GPRel64Directive = nullptr;
65  GPRel32Directive = nullptr;
66  GlobalDirective = "\t.globl\t";
67  HasSetDirective = true;
68  HasAggressiveSymbolFolding = true;
69  COMMDirectiveAlignmentIsInBytes = true;
70  LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
71  HasDotTypeDotSizeDirective = true;
72  HasSingleParameterDotFile = true;
73  HasIdentDirective = false;
74  HasNoDeadStrip = false;
75  WeakRefDirective = nullptr;
76  HasWeakDefDirective = false;
77  HasWeakDefCanBeHiddenDirective = false;
78  HasLinkOnceDirective = false;
79  HiddenVisibilityAttr = MCSA_Hidden;
80  HiddenDeclarationVisibilityAttr = MCSA_Hidden;
81  ProtectedVisibilityAttr = MCSA_Protected;
82  HasLEB128 = false;
83  SupportsDebugInformation = false;
84  ExceptionsType = ExceptionHandling::None;
85  WinEHEncodingType = WinEH::EncodingType::ET_Invalid;
86  DwarfUsesRelocationsAcrossSections = true;
87  DwarfFDESymbolsUseAbsDiff = false;
88  DwarfRegNumForCFI = false;
89  NeedsDwarfSectionOffsetDirective = false;
90  UseParensForSymbolVariant = false;
91
92  // FIXME: Clang's logic should be synced with the logic used to initialize
93  //        this member and the two implementations should be merged.
94  // For reference:
95  // - Solaris always enables the integrated assembler by default
96  //   - SparcELFMCAsmInfo and X86ELFMCAsmInfo are handling this case
97  // - Windows always enables the integrated assembler by default
98  //   - MCAsmInfoCOFF is handling this case, should it be MCAsmInfoMicrosoft?
99  // - MachO targets always enables the integrated assembler by default
100  //   - MCAsmInfoDarwin is handling this case
101  // - Generic_GCC toolchains enable the integrated assembler on a per
102  //   architecture basis.
103  //   - The target subclasses for AArch64, ARM, and X86 handle these cases
104  UseIntegratedAssembler = false;
105
106  CompressDebugSections = false;
107}
108
109MCAsmInfo::~MCAsmInfo() {
110}
111
112const MCExpr *
113MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
114                                       unsigned Encoding,
115                                       MCStreamer &Streamer) const {
116  return getExprForFDESymbol(Sym, Encoding, Streamer);
117}
118
119const MCExpr *
120MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
121                               unsigned Encoding,
122                               MCStreamer &Streamer) const {
123  if (!(Encoding & dwarf::DW_EH_PE_pcrel))
124    return MCSymbolRefExpr::Create(Sym, Streamer.getContext());
125
126  MCContext &Context = Streamer.getContext();
127  const MCExpr *Res = MCSymbolRefExpr::Create(Sym, Context);
128  MCSymbol *PCSym = Context.CreateTempSymbol();
129  Streamer.EmitLabel(PCSym);
130  const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, Context);
131  return MCBinaryExpr::CreateSub(Res, PC, Context);
132}
133