//===- lib/MC/MCContext.cpp - Machine Code Context ------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/MC/MCContext.h"

#include "llvm/MC/MCAtom.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
using namespace llvm;

MCContext::MCContext()
{
}

MCContext::~MCContext() {
}

MCSection *MCContext::GetSection(const char *Name) {
  MCSection *&Entry = Sections[Name];
  
  if (!Entry)
    Entry = new (*this) MCSection(Name);

  return Entry;
}
    
MCAtom *MCContext::CreateAtom(MCSection *Section) {
  return new (*this) MCAtom(Section);
}

MCSymbol *MCContext::CreateSymbol(MCAtom *Atom, const char *Name) {
  assert(Name[0] != '\0' && "Normal symbols cannot be unnamed!");

  // Create and bind the symbol, and ensure that names are unique.
  MCSymbol *&Entry = Symbols[Name];
  assert(!Entry && "Duplicate symbol definition!");
  return Entry = new (*this) MCSymbol(Atom, Name, false);
}

/// GetOrCreateSymbol - Lookup the symbol inside with the specified
/// @param Name.  If it exists, return it.  If not, create a forward
/// reference and return it.
///
/// @param Name - The symbol name, which must be unique across all symbols.
MCSymbol *MCContext::GetOrCreateSymbol(const char *Name) {
  MCSymbol *&Entry = Symbols[Name];
  if (Entry) return Entry;

  // FIXME: is a null atom the right way to make a forward ref?
  return Entry = new (*this) MCSymbol(0, Name, false);
}


MCSymbol *MCContext::CreateTemporarySymbol(MCAtom *Atom, const char *Name) {
  // If unnamed, just create a symbol.
  if (Name[0] == '\0')
    new (*this) MCSymbol(Atom, "", true);
    
  // Otherwise create as usual.
  MCSymbol *&Entry = Symbols[Name];
  assert(!Entry && "Duplicate symbol definition!");
  return Entry = new (*this) MCSymbol(Atom, Name, true);
}

MCSymbol *MCContext::LookupSymbol(const char *Name) const {
  return Symbols.lookup(Name);
}

void MCContext::ClearSymbolValue(MCSymbol *Sym) {
  SymbolValues.erase(Sym);
}

void MCContext::SetSymbolValue(MCSymbol *Sym, const MCValue &Value) {
  SymbolValues[Sym] = Value;
}

const MCValue *MCContext::GetSymbolValue(MCSymbol *Sym) const {
  DenseMap<MCSymbol*, MCValue>::iterator it = SymbolValues.find(Sym);

  if (it == SymbolValues.end())
    return 0;

  return &it->second;
}