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/ADT/StringExtras.h"
16 #include "llvm/BinaryFormat/Dwarf.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCExpr.h"
19 #include "llvm/MC/MCStreamer.h"
20 #include "llvm/Support/CommandLine.h"
21
22 using namespace llvm;
23
24 namespace {
25 enum DefaultOnOff { Default, Enable, Disable };
26 }
27 static cl::opt<DefaultOnOff> DwarfExtendedLoc(
28 "dwarf-extended-loc", cl::Hidden,
29 cl::desc("Disable emission of the extended flags in .loc directives."),
30 cl::values(clEnumVal(Default, "Default for platform"),
31 clEnumVal(Enable, "Enabled"), clEnumVal(Disable, "Disabled")),
32 cl::init(Default));
33
34 namespace llvm {
35 cl::opt<cl::boolOrDefault> UseLEB128Directives(
36 "use-leb128-directives", cl::Hidden,
37 cl::desc(
38 "Disable the usage of LEB128 directives, and generate .byte instead."),
39 cl::init(cl::BOU_UNSET));
40 }
41
MCAsmInfo()42 MCAsmInfo::MCAsmInfo() {
43 SeparatorString = ";";
44 CommentString = "#";
45 LabelSuffix = ":";
46 PrivateGlobalPrefix = "L";
47 PrivateLabelPrefix = PrivateGlobalPrefix;
48 LinkerPrivateGlobalPrefix = "";
49 InlineAsmStart = "APP";
50 InlineAsmEnd = "NO_APP";
51 Code16Directive = ".code16";
52 Code32Directive = ".code32";
53 Code64Directive = ".code64";
54 ZeroDirective = "\t.zero\t";
55 AsciiDirective = "\t.ascii\t";
56 AscizDirective = "\t.asciz\t";
57 Data8bitsDirective = "\t.byte\t";
58 Data16bitsDirective = "\t.short\t";
59 Data32bitsDirective = "\t.long\t";
60 Data64bitsDirective = "\t.quad\t";
61 GlobalDirective = "\t.globl\t";
62 WeakDirective = "\t.weak\t";
63 if (DwarfExtendedLoc != Default)
64 SupportsExtendedDwarfLocDirective = DwarfExtendedLoc == Enable;
65 if (UseLEB128Directives != cl::BOU_UNSET)
66 HasLEB128Directives = UseLEB128Directives == cl::BOU_TRUE;
67 UseIntegratedAssembler = true;
68 ParseInlineAsmUsingAsmParser = false;
69 PreserveAsmComments = true;
70 PPCUseFullRegisterNames = false;
71 }
72
73 MCAsmInfo::~MCAsmInfo() = default;
74
addInitialFrameState(const MCCFIInstruction & Inst)75 void MCAsmInfo::addInitialFrameState(const MCCFIInstruction &Inst) {
76 InitialFrameState.push_back(Inst);
77 }
78
79 const MCExpr *
getExprForPersonalitySymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const80 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
81 unsigned Encoding,
82 MCStreamer &Streamer) const {
83 return getExprForFDESymbol(Sym, Encoding, Streamer);
84 }
85
86 const MCExpr *
getExprForFDESymbol(const MCSymbol * Sym,unsigned Encoding,MCStreamer & Streamer) const87 MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
88 unsigned Encoding,
89 MCStreamer &Streamer) const {
90 if (!(Encoding & dwarf::DW_EH_PE_pcrel))
91 return MCSymbolRefExpr::create(Sym, Streamer.getContext());
92
93 MCContext &Context = Streamer.getContext();
94 const MCExpr *Res = MCSymbolRefExpr::create(Sym, Context);
95 MCSymbol *PCSym = Context.createTempSymbol();
96 Streamer.emitLabel(PCSym);
97 const MCExpr *PC = MCSymbolRefExpr::create(PCSym, Context);
98 return MCBinaryExpr::createSub(Res, PC, Context);
99 }
100
isAcceptableChar(char C) const101 bool MCAsmInfo::isAcceptableChar(char C) const {
102 if (C == '@')
103 return doesAllowAtInName();
104
105 return isAlnum(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