MCAsmInfo.cpp revision 256281 
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  PCSymbol = "$";
38  SeparatorString = ";";
39  CommentColumn = 40;
40  CommentString = "#";
41  LabelSuffix = ":";
42  DebugLabelSuffix = ":";
43  GlobalPrefix = "";
44  PrivateGlobalPrefix = ".";
45  LinkerPrivateGlobalPrefix = "";
46  InlineAsmStart = "APP";
47  InlineAsmEnd = "NO_APP";
48  Code16Directive = ".code16";
49  Code32Directive = ".code32";
50  Code64Directive = ".code64";
51  AssemblerDialect = 0;
52  AllowQuotesInName = false;
53  AllowNameToStartWithDigit = false;
54  AllowPeriodsInName = true;
55  AllowUTF8 = true;
56  UseDataRegionDirectives = false;
57  ZeroDirective = "\t.zero\t";
58  AsciiDirective = "\t.ascii\t";
59  AscizDirective = "\t.asciz\t";
60  Data8bitsDirective = "\t.byte\t";
61  Data16bitsDirective = "\t.short\t";
62  Data32bitsDirective = "\t.long\t";
63  Data64bitsDirective = "\t.quad\t";
64  SunStyleELFSectionSwitchSyntax = false;
65  UsesELFSectionDirectiveForBSS = false;
66  AlignDirective = "\t.align\t";
67  AlignmentIsInBytes = true;
68  TextAlignFillValue = 0;
69  GPRel64Directive = 0;
70  GPRel32Directive = 0;
71  GlobalDirective = "\t.globl\t";
72  HasSetDirective = true;
73  HasAggressiveSymbolFolding = true;
74  COMMDirectiveAlignmentIsInBytes = true;
75  LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
76  HasDotTypeDotSizeDirective = true;
77  HasSingleParameterDotFile = true;
78  HasNoDeadStrip = false;
79  HasSymbolResolver = false;
80  WeakRefDirective = 0;
81  WeakDefDirective = 0;
82  LinkOnceDirective = 0;
83  HiddenVisibilityAttr = MCSA_Hidden;
84  HiddenDeclarationVisibilityAttr = MCSA_Hidden;
85  ProtectedVisibilityAttr = MCSA_Protected;
86  HasLEB128 = false;
87  SupportsDebugInformation = false;
88  ExceptionsType = ExceptionHandling::None;
89  DwarfUsesInlineInfoSection = false;
90  DwarfUsesRelocationsAcrossSections = true;
91  DwarfRegNumForCFI = false;
92  HasMicrosoftFastStdCallMangling = false;
93  NeedsDwarfSectionOffsetDirective = false;
94}
95
96MCAsmInfo::~MCAsmInfo() {
97}
98
99
100unsigned MCAsmInfo::getULEB128Size(unsigned Value) {
101  unsigned Size = 0;
102  do {
103    Value >>= 7;
104    Size += sizeof(int8_t);
105  } while (Value);
106  return Size;
107}
108
109unsigned MCAsmInfo::getSLEB128Size(int Value) {
110  unsigned Size = 0;
111  int Sign = Value >> (8 * sizeof(Value) - 1);
112  bool IsMore;
113
114  do {
115    unsigned Byte = Value & 0x7f;
116    Value >>= 7;
117    IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
118    Size += sizeof(int8_t);
119  } while (IsMore);
120  return Size;
121}
122
123const MCExpr *
124MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
125                                       unsigned Encoding,
126                                       MCStreamer &Streamer) const {
127  return getExprForFDESymbol(Sym, Encoding, Streamer);
128}
129
130const MCExpr *
131MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
132                               unsigned Encoding,
133                               MCStreamer &Streamer) const {
134  if (!(Encoding & dwarf::DW_EH_PE_pcrel))
135    return MCSymbolRefExpr::Create(Sym, Streamer.getContext());
136
137  MCContext &Context = Streamer.getContext();
138  const MCExpr *Res = MCSymbolRefExpr::Create(Sym, Context);
139  MCSymbol *PCSym = Context.CreateTempSymbol();
140  Streamer.EmitLabel(PCSym);
141  const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, Context);
142  return MCBinaryExpr::CreateSub(Res, PC, Context);
143}
144