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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>
23 using namespace llvm;
24 
MCAsmInfo()25 MCAsmInfo::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   PCSymbol = "$";
39   SeparatorString = ";";
40   CommentColumn = 40;
41   CommentString = "#";
42   LabelSuffix = ":";
43   DebugLabelSuffix = ":";
44   GlobalPrefix = "";
45   PrivateGlobalPrefix = ".";
46   LinkerPrivateGlobalPrefix = "";
47   InlineAsmStart = "APP";
48   InlineAsmEnd = "NO_APP";
49   Code16Directive = ".code16";
50   Code32Directive = ".code32";
51   Code64Directive = ".code64";
52   AssemblerDialect = 0;
53   AllowQuotesInName = false;
54   AllowNameToStartWithDigit = false;
55   AllowPeriodsInName = true;
56   AllowUTF8 = true;
57   UseDataRegionDirectives = false;
58   ZeroDirective = "\t.zero\t";
59   AsciiDirective = "\t.ascii\t";
60   AscizDirective = "\t.asciz\t";
61   Data8bitsDirective = "\t.byte\t";
62   Data16bitsDirective = "\t.short\t";
63   Data32bitsDirective = "\t.long\t";
64   Data64bitsDirective = "\t.quad\t";
65   SunStyleELFSectionSwitchSyntax = false;
66   UsesELFSectionDirectiveForBSS = false;
67   AlignDirective = "\t.align\t";
68   AlignmentIsInBytes = true;
69   TextAlignFillValue = 0;
70   GPRel64Directive = 0;
71   GPRel32Directive = 0;
72   GlobalDirective = "\t.globl\t";
73   HasSetDirective = true;
74   HasAggressiveSymbolFolding = true;
75   COMMDirectiveAlignmentIsInBytes = true;
76   LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
77   HasDotTypeDotSizeDirective = true;
78   HasSingleParameterDotFile = true;
79   HasNoDeadStrip = false;
80   HasSymbolResolver = false;
81   WeakRefDirective = 0;
82   WeakDefDirective = 0;
83   LinkOnceDirective = 0;
84   HiddenVisibilityAttr = MCSA_Hidden;
85   HiddenDeclarationVisibilityAttr = MCSA_Hidden;
86   ProtectedVisibilityAttr = MCSA_Protected;
87   HasLEB128 = false;
88   SupportsDebugInformation = false;
89   ExceptionsType = ExceptionHandling::None;
90   DwarfUsesInlineInfoSection = false;
91   DwarfUsesRelocationsAcrossSections = true;
92   DwarfRegNumForCFI = false;
93   HasMicrosoftFastStdCallMangling = false;
94   NeedsDwarfSectionOffsetDirective = false;
95 }
96 
~MCAsmInfo()97 MCAsmInfo::~MCAsmInfo() {
98 }
99 
100 
getULEB128Size(uint64_t Value)101 unsigned MCAsmInfo::getULEB128Size(uint64_t Value) {
102   unsigned Size = 0;
103   do {
104     Value >>= 7;
105     Size += sizeof(int8_t);
106   } while (Value);
107   return Size;
108 }
109 
getSLEB128Size(int64_t Value)110 unsigned MCAsmInfo::getSLEB128Size(int64_t Value) {
111   unsigned Size = 0;
112   int Sign = Value >> (8 * sizeof(Value) - 1);
113   bool IsMore;
114 
115   do {
116     unsigned Byte = Value & 0x7f;
117     Value >>= 7;
118     IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
119     Size += sizeof(int8_t);
120   } while (IsMore);
121   return Size;
122 }
123 
124 const MCExpr *
getExprForPersonalitySymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const125 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
126                                        unsigned Encoding,
127                                        MCStreamer &Streamer) const {
128   return getExprForFDESymbol(Sym, Encoding, Streamer);
129 }
130 
131 const MCExpr *
getExprForFDESymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const132 MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
133                                unsigned Encoding,
134                                MCStreamer &Streamer) const {
135   if (!(Encoding & dwarf::DW_EH_PE_pcrel))
136     return MCSymbolRefExpr::Create(Sym, Streamer.getContext());
137 
138   MCContext &Context = Streamer.getContext();
139   const MCExpr *Res = MCSymbolRefExpr::Create(Sym, Context);
140   MCSymbol *PCSym = Context.CreateTempSymbol();
141   Streamer.EmitLabel(PCSym);
142   const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, Context);
143   return MCBinaryExpr::CreateSub(Res, PC, Context);
144 }
145