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//===- lib/MC/MCSymbol.cpp - MCSymbol implementation ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
// Sentinel value for the absolute pseudo section.
const MCSection *MCSymbol::AbsolutePseudoSection =
reinterpret_cast<const MCSection *>(1);
static bool isAcceptableChar(char C) {
if ((C < 'a' || C > 'z') &&
(C < 'A' || C > 'Z') &&
(C < '0' || C > '9') &&
C != '_' && C != '$' && C != '.' && C != '@')
return false;
return true;
}
static char HexDigit(int V) {
return V < 10 ? V+'0' : V+'A'-10;
}
static void MangleLetter(raw_ostream &OS, unsigned char C) {
OS << '_' << HexDigit(C >> 4) << HexDigit(C & 15) << '_';
}
/// NameNeedsEscaping - Return true if the identifier \arg Str needs quotes
/// for this assembler.
static bool NameNeedsEscaping(const StringRef &Str, const MCAsmInfo &MAI) {
assert(!Str.empty() && "Cannot create an empty MCSymbol");
// If the first character is a number and the target does not allow this, we
// need quotes.
if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9')
return true;
// If any of the characters in the string is an unacceptable character, force
// quotes.
for (unsigned i = 0, e = Str.size(); i != e; ++i)
if (!isAcceptableChar(Str[i]))
return true;
return false;
}
static void PrintMangledName(raw_ostream &OS, StringRef Str,
const MCAsmInfo &MAI) {
// The first character is not allowed to be a number unless the target
// explicitly allows it.
if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9') {
MangleLetter(OS, Str[0]);
Str = Str.substr(1);
}
for (unsigned i = 0, e = Str.size(); i != e; ++i) {
if (!isAcceptableChar(Str[i]))
MangleLetter(OS, Str[i]);
else
OS << Str[i];
}
}
/// PrintMangledQuotedName - On systems that support quoted symbols, we still
/// have to escape some (obscure) characters like " and \n which would break the
/// assembler's lexing.
static void PrintMangledQuotedName(raw_ostream &OS, StringRef Str) {
OS << '"';
for (unsigned i = 0, e = Str.size(); i != e; ++i) {
if (Str[i] == '"')
OS << "_QQ_";
else if (Str[i] == '\n')
OS << "_NL_";
else
OS << Str[i];
}
OS << '"';
}
void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const {
if (MAI == 0 || !NameNeedsEscaping(getName(), *MAI)) {
OS << getName();
return;
}
// On systems that do not allow quoted names, print with mangling.
if (!MAI->doesAllowQuotesInName())
return PrintMangledName(OS, getName(), *MAI);
// If the string contains a double quote or newline, we still have to mangle
// it.
if (getName().find('"') != std::string::npos ||
getName().find('\n') != std::string::npos)
return PrintMangledQuotedName(OS, getName());
OS << '"' << getName() << '"';
}
void MCSymbol::dump() const {
print(errs(), 0);
}
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