llvm-project/llvm/lib/MC/MCAsmInfo.cpp

135 lines
4.8 KiB
C++

//===- MCAsmInfo.cpp - Asm Info -------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines target asm properties related what form asm statements
// should take.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
enum DefaultOnOff { Default, Enable, Disable };
static cl::opt<DefaultOnOff> DwarfExtendedLoc(
"dwarf-extended-loc", cl::Hidden,
cl::desc("Disable emission of the extended flags in .loc directives."),
cl::values(clEnumVal(Default, "Default for platform"),
clEnumVal(Enable, "Enabled"), clEnumVal(Disable, "Disabled")),
cl::init(Default));
cl::opt<cl::boolOrDefault> UseLEB128Directives(
"use-leb128-directives", cl::Hidden,
cl::desc(
"Disable the usage of LEB128 directives, and generate .byte instead."),
cl::init(cl::BOU_UNSET));
MCAsmInfo::MCAsmInfo() {
SeparatorString = ";";
CommentString = "#";
LabelSuffix = ":";
PrivateGlobalPrefix = "L";
PrivateLabelPrefix = PrivateGlobalPrefix;
LinkerPrivateGlobalPrefix = "";
InlineAsmStart = "APP";
InlineAsmEnd = "NO_APP";
Code16Directive = ".code16";
Code32Directive = ".code32";
Code64Directive = ".code64";
ZeroDirective = "\t.zero\t";
AsciiDirective = "\t.ascii\t";
AscizDirective = "\t.asciz\t";
Data8bitsDirective = "\t.byte\t";
Data16bitsDirective = "\t.short\t";
Data32bitsDirective = "\t.long\t";
Data64bitsDirective = "\t.quad\t";
GlobalDirective = "\t.globl\t";
WeakDirective = "\t.weak\t";
if (DwarfExtendedLoc != Default)
SupportsExtendedDwarfLocDirective = DwarfExtendedLoc == Enable;
if (UseLEB128Directives != cl::BOU_UNSET)
HasLEB128Directives = UseLEB128Directives == cl::BOU_TRUE;
// FIXME: Clang's logic should be synced with the logic used to initialize
// this member and the two implementations should be merged.
// For reference:
// - Solaris always enables the integrated assembler by default
// - SparcELFMCAsmInfo and X86ELFMCAsmInfo are handling this case
// - Windows always enables the integrated assembler by default
// - MCAsmInfoCOFF is handling this case, should it be MCAsmInfoMicrosoft?
// - MachO targets always enables the integrated assembler by default
// - MCAsmInfoDarwin is handling this case
// - Generic_GCC toolchains enable the integrated assembler on a per
// architecture basis.
// - The target subclasses for AArch64, ARM, and X86 handle these cases
UseIntegratedAssembler = true;
PreserveAsmComments = true;
}
MCAsmInfo::~MCAsmInfo() = default;
void MCAsmInfo::addInitialFrameState(const MCCFIInstruction &Inst) {
InitialFrameState.push_back(Inst);
}
bool MCAsmInfo::isSectionAtomizableBySymbols(const MCSection &Section) const {
return false;
}
const MCExpr *
MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
unsigned Encoding,
MCStreamer &Streamer) const {
return getExprForFDESymbol(Sym, Encoding, Streamer);
}
const MCExpr *
MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
unsigned Encoding,
MCStreamer &Streamer) const {
if (!(Encoding & dwarf::DW_EH_PE_pcrel))
return MCSymbolRefExpr::create(Sym, Streamer.getContext());
MCContext &Context = Streamer.getContext();
const MCExpr *Res = MCSymbolRefExpr::create(Sym, Context);
MCSymbol *PCSym = Context.createTempSymbol();
Streamer.emitLabel(PCSym);
const MCExpr *PC = MCSymbolRefExpr::create(PCSym, Context);
return MCBinaryExpr::createSub(Res, PC, Context);
}
bool MCAsmInfo::isAcceptableChar(char C) const {
return (C >= 'a' && C <= 'z') || (C >= 'A' && C <= 'Z') ||
(C >= '0' && C <= '9') || C == '_' || C == '$' || C == '.' || C == '@';
}
bool MCAsmInfo::isValidUnquotedName(StringRef Name) const {
if (Name.empty())
return false;
// If any of the characters in the string is an unacceptable character, force
// quotes.
for (char C : Name) {
if (!isAcceptableChar(C))
return false;
}
return true;
}
bool MCAsmInfo::shouldOmitSectionDirective(StringRef SectionName) const {
// FIXME: Does .section .bss/.data/.text work everywhere??
return SectionName == ".text" || SectionName == ".data" ||
(SectionName == ".bss" && !usesELFSectionDirectiveForBSS());
}