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 MaxInstLength = 4;
36 MinInstAlignment = 1;
37 DollarIsPC = false;
38 SeparatorString = ";";
39 CommentString = "#";
40 LabelSuffix = ":";
41 UseAssignmentForEHBegin = false;
42 NeedsLocalForSize = false;
43 PrivateGlobalPrefix = "L";
44 PrivateLabelPrefix = PrivateGlobalPrefix;
45 LinkerPrivateGlobalPrefix = "";
46 InlineAsmStart = "APP";
47 InlineAsmEnd = "NO_APP";
48 Code16Directive = ".code16";
49 Code32Directive = ".code32";
50 Code64Directive = ".code64";
51 AssemblerDialect = 0;
52 AllowAtInName = false;
53 SupportsQuotedNames = true;
54 UseDataRegionDirectives = false;
55 ZeroDirective = "\t.zero\t";
56 AsciiDirective = "\t.ascii\t";
57 AscizDirective = "\t.asciz\t";
58 Data8bitsDirective = "\t.byte\t";
59 Data16bitsDirective = "\t.short\t";
60 Data32bitsDirective = "\t.long\t";
61 Data64bitsDirective = "\t.quad\t";
62 SunStyleELFSectionSwitchSyntax = false;
63 UsesELFSectionDirectiveForBSS = false;
64 AlignmentIsInBytes = true;
65 TextAlignFillValue = 0;
66 GPRel64Directive = nullptr;
67 GPRel32Directive = nullptr;
68 GlobalDirective = "\t.globl\t";
69 SetDirectiveSuppressesReloc = false;
70 HasAggressiveSymbolFolding = true;
71 COMMDirectiveAlignmentIsInBytes = true;
72 LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
73 HasFunctionAlignment = true;
74 HasDotTypeDotSizeDirective = true;
75 HasSingleParameterDotFile = true;
76 HasIdentDirective = false;
77 HasNoDeadStrip = false;
78 HasAltEntry = false;
79 WeakDirective = "\t.weak\t";
80 WeakRefDirective = nullptr;
81 HasWeakDefDirective = false;
82 HasWeakDefCanBeHiddenDirective = false;
83 HasLinkOnceDirective = false;
84 HiddenVisibilityAttr = MCSA_Hidden;
85 HiddenDeclarationVisibilityAttr = MCSA_Hidden;
86 ProtectedVisibilityAttr = MCSA_Protected;
87 SupportsDebugInformation = false;
88 ExceptionsType = ExceptionHandling::None;
89 WinEHEncodingType = WinEH::EncodingType::Invalid;
90 DwarfUsesRelocationsAcrossSections = true;
91 DwarfFDESymbolsUseAbsDiff = false;
92 DwarfRegNumForCFI = false;
93 NeedsDwarfSectionOffsetDirective = false;
94 UseParensForSymbolVariant = false;
95 UseLogicalShr = true;
96
97 // FIXME: Clang's logic should be synced with the logic used to initialize
98 // this member and the two implementations should be merged.
99 // For reference:
100 // - Solaris always enables the integrated assembler by default
101 // - SparcELFMCAsmInfo and X86ELFMCAsmInfo are handling this case
102 // - Windows always enables the integrated assembler by default
103 // - MCAsmInfoCOFF is handling this case, should it be MCAsmInfoMicrosoft?
104 // - MachO targets always enables the integrated assembler by default
105 // - MCAsmInfoDarwin is handling this case
106 // - Generic_GCC toolchains enable the integrated assembler on a per
107 // architecture basis.
108 // - The target subclasses for AArch64, ARM, and X86 handle these cases
109 UseIntegratedAssembler = false;
110 PreserveAsmComments = true;
111
112 CompressDebugSections = DebugCompressionType::DCT_None;
113 }
114
~MCAsmInfo()115 MCAsmInfo::~MCAsmInfo() {
116 }
117
isSectionAtomizableBySymbols(const MCSection & Section) const118 bool MCAsmInfo::isSectionAtomizableBySymbols(const MCSection &Section) const {
119 return false;
120 }
121
122 const MCExpr *
getExprForPersonalitySymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const123 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
124 unsigned Encoding,
125 MCStreamer &Streamer) const {
126 return getExprForFDESymbol(Sym, Encoding, Streamer);
127 }
128
129 const MCExpr *
getExprForFDESymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const130 MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
131 unsigned Encoding,
132 MCStreamer &Streamer) const {
133 if (!(Encoding & dwarf::DW_EH_PE_pcrel))
134 return MCSymbolRefExpr::create(Sym, Streamer.getContext());
135
136 MCContext &Context = Streamer.getContext();
137 const MCExpr *Res = MCSymbolRefExpr::create(Sym, Context);
138 MCSymbol *PCSym = Context.createTempSymbol();
139 Streamer.EmitLabel(PCSym);
140 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, Context);
141 return MCBinaryExpr::createSub(Res, PC, Context);
142 }
143
isAcceptableChar(char C)144 static bool isAcceptableChar(char C) {
145 return (C >= 'a' && C <= 'z') || (C >= 'A' && C <= 'Z') ||
146 (C >= '0' && C <= '9') || C == '_' || C == '$' || C == '.' || C == '@';
147 }
148
isValidUnquotedName(StringRef Name) const149 bool MCAsmInfo::isValidUnquotedName(StringRef Name) const {
150 if (Name.empty())
151 return false;
152
153 // If any of the characters in the string is an unacceptable character, force
154 // quotes.
155 for (char C : Name) {
156 if (!isAcceptableChar(C))
157 return false;
158 }
159
160 return true;
161 }
162
shouldOmitSectionDirective(StringRef SectionName) const163 bool MCAsmInfo::shouldOmitSectionDirective(StringRef SectionName) const {
164 // FIXME: Does .section .bss/.data/.text work everywhere??
165 return SectionName == ".text" || SectionName == ".data" ||
166 (SectionName == ".bss" && !usesELFSectionDirectiveForBSS());
167 }
168