llvm-6502/lib/MC/MCSymbol.cpp
Rafael Espindola 4af106a677 Add back r203962, r204028 and r204059.
This reverts commit r204137.

This includes a fix for handling aliases of aliases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204178 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-18 20:40:38 +00:00

117 lines
3.2 KiB
C++

//===- 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/MCExpr.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.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;
}
/// NameNeedsQuoting - Return true if the identifier \p Str needs quotes to be
/// syntactically correct.
static bool NameNeedsQuoting(StringRef Str) {
assert(!Str.empty() && "Cannot create an empty MCSymbol");
// 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;
}
const MCSymbol &MCSymbol::AliasedSymbol() const {
const MCSymbol *S = this;
while (S->isVariable()) {
const MCExpr *Value = S->getVariableValue();
if (Value->getKind() != MCExpr::SymbolRef)
return *S;
const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value);
S = &Ref->getSymbol();
}
return *S;
}
const MCSymbol *MCSymbol::getBaseSymbol(const MCAsmLayout &Layout) const {
// FIXME: shouldn't EvaluateAsRelocatable be responsible for following as many
// variables as possible?
const MCSymbol *S = this;
while (S->isVariable()) {
const MCExpr *Expr = S->getVariableValue();
MCValue Value;
if (!Expr->EvaluateAsRelocatable(Value, &Layout))
return nullptr;
if (Value.getSymB())
return nullptr;
const MCSymbolRefExpr *A = Value.getSymA();
if (!A)
return nullptr;
S = &A->getSymbol();
}
return S;
}
void MCSymbol::setVariableValue(const MCExpr *Value) {
assert(!IsUsed && "Cannot set a variable that has already been used.");
assert(Value && "Invalid variable value!");
this->Value = Value;
// Variables should always be marked as in the same "section" as the value.
const MCSection *Section = Value->FindAssociatedSection();
if (Section)
setSection(*Section);
else
setUndefined();
}
void MCSymbol::print(raw_ostream &OS) const {
// The name for this MCSymbol is required to be a valid target name. However,
// some targets support quoting names with funny characters. If the name
// contains a funny character, then print it quoted.
StringRef Name = getName();
if (!NameNeedsQuoting(Name)) {
OS << Name;
return;
}
OS << '"';
for (unsigned I = 0, E = Name.size(); I != E; ++I) {
char C = Name[I];
if (C == '\n')
OS << "\\n";
else if (C == '"')
OS << "\\\"";
else
OS << C;
}
OS << '"';
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MCSymbol::dump() const {
print(dbgs());
}
#endif