1 //===- MCAsmInfo.cpp - Asm Info -------------------------------------------===//
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 defines target asm properties related what form asm statements
10 // should take.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/MC/MCAsmInfo.h"
15 #include "llvm/BinaryFormat/Dwarf.h"
16 #include "llvm/MC/MCContext.h"
17 #include "llvm/MC/MCExpr.h"
18 #include "llvm/MC/MCStreamer.h"
19 #include "llvm/Support/CommandLine.h"
20
21 using namespace llvm;
22
23 enum DefaultOnOff { Default, Enable, Disable };
24 static cl::opt<DefaultOnOff> DwarfExtendedLoc(
25 "dwarf-extended-loc", cl::Hidden,
26 cl::desc("Disable emission of the extended flags in .loc directives."),
27 cl::values(clEnumVal(Default, "Default for platform"),
28 clEnumVal(Enable, "Enabled"), clEnumVal(Disable, "Disabled")),
29 cl::init(Default));
30
MCAsmInfo()31 MCAsmInfo::MCAsmInfo() {
32 SeparatorString = ";";
33 CommentString = "#";
34 LabelSuffix = ":";
35 PrivateGlobalPrefix = "L";
36 PrivateLabelPrefix = PrivateGlobalPrefix;
37 LinkerPrivateGlobalPrefix = "";
38 InlineAsmStart = "APP";
39 InlineAsmEnd = "NO_APP";
40 Code16Directive = ".code16";
41 Code32Directive = ".code32";
42 Code64Directive = ".code64";
43 ZeroDirective = "\t.zero\t";
44 AsciiDirective = "\t.ascii\t";
45 AscizDirective = "\t.asciz\t";
46 Data8bitsDirective = "\t.byte\t";
47 Data16bitsDirective = "\t.short\t";
48 Data32bitsDirective = "\t.long\t";
49 Data64bitsDirective = "\t.quad\t";
50 GlobalDirective = "\t.globl\t";
51 WeakDirective = "\t.weak\t";
52 if (DwarfExtendedLoc != Default)
53 SupportsExtendedDwarfLocDirective = DwarfExtendedLoc == Enable;
54
55 // FIXME: Clang's logic should be synced with the logic used to initialize
56 // this member and the two implementations should be merged.
57 // For reference:
58 // - Solaris always enables the integrated assembler by default
59 // - SparcELFMCAsmInfo and X86ELFMCAsmInfo are handling this case
60 // - Windows always enables the integrated assembler by default
61 // - MCAsmInfoCOFF is handling this case, should it be MCAsmInfoMicrosoft?
62 // - MachO targets always enables the integrated assembler by default
63 // - MCAsmInfoDarwin is handling this case
64 // - Generic_GCC toolchains enable the integrated assembler on a per
65 // architecture basis.
66 // - The target subclasses for AArch64, ARM, and X86 handle these cases
67 UseIntegratedAssembler = false;
68 PreserveAsmComments = true;
69 }
70
71 MCAsmInfo::~MCAsmInfo() = default;
72
addInitialFrameState(const MCCFIInstruction & Inst)73 void MCAsmInfo::addInitialFrameState(const MCCFIInstruction &Inst) {
74 InitialFrameState.push_back(Inst);
75 }
76
isSectionAtomizableBySymbols(const MCSection & Section) const77 bool MCAsmInfo::isSectionAtomizableBySymbols(const MCSection &Section) const {
78 return false;
79 }
80
81 const MCExpr *
getExprForPersonalitySymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const82 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
83 unsigned Encoding,
84 MCStreamer &Streamer) const {
85 return getExprForFDESymbol(Sym, Encoding, Streamer);
86 }
87
88 const MCExpr *
getExprForFDESymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const89 MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
90 unsigned Encoding,
91 MCStreamer &Streamer) const {
92 if (!(Encoding & dwarf::DW_EH_PE_pcrel))
93 return MCSymbolRefExpr::create(Sym, Streamer.getContext());
94
95 MCContext &Context = Streamer.getContext();
96 const MCExpr *Res = MCSymbolRefExpr::create(Sym, Context);
97 MCSymbol *PCSym = Context.createTempSymbol();
98 Streamer.EmitLabel(PCSym);
99 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, Context);
100 return MCBinaryExpr::createSub(Res, PC, Context);
101 }
102
isAcceptableChar(char C) const103 bool MCAsmInfo::isAcceptableChar(char C) const {
104 return (C >= 'a' && C <= 'z') || (C >= 'A' && C <= 'Z') ||
105 (C >= '0' && C <= '9') || C == '_' || C == '$' || C == '.' || C == '@';
106 }
107
isValidUnquotedName(StringRef Name) const108 bool MCAsmInfo::isValidUnquotedName(StringRef Name) const {
109 if (Name.empty())
110 return false;
111
112 // If any of the characters in the string is an unacceptable character, force
113 // quotes.
114 for (char C : Name) {
115 if (!isAcceptableChar(C))
116 return false;
117 }
118
119 return true;
120 }
121
shouldOmitSectionDirective(StringRef SectionName) const122 bool MCAsmInfo::shouldOmitSectionDirective(StringRef SectionName) const {
123 // FIXME: Does .section .bss/.data/.text work everywhere??
124 return SectionName == ".text" || SectionName == ".data" ||
125 (SectionName == ".bss" && !usesELFSectionDirectiveForBSS());
126 }
127