//===--- PreprocessingRecord.cpp - Record of Preprocessing ------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements the PreprocessingRecord class, which maintains a record
//  of what occurred during preprocessing, and its helpers.
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/PreprocessingRecord.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/Token.h"

using namespace clang;

ExternalPreprocessingRecordSource::~ExternalPreprocessingRecordSource() { }

void PreprocessingRecord::MaybeLoadPreallocatedEntities() const {
  if (!ExternalSource || LoadedPreallocatedEntities)
    return;
  
  LoadedPreallocatedEntities = true;
  ExternalSource->ReadPreprocessedEntities();
}

PreprocessingRecord::PreprocessingRecord()
  : ExternalSource(0), NumPreallocatedEntities(0), 
    LoadedPreallocatedEntities(false)
{
}

PreprocessingRecord::iterator 
PreprocessingRecord::begin(bool OnlyLocalEntities) {
  if (OnlyLocalEntities)
    return PreprocessedEntities.begin() + NumPreallocatedEntities;
  
  MaybeLoadPreallocatedEntities();
  return PreprocessedEntities.begin();
}

PreprocessingRecord::iterator PreprocessingRecord::end(bool OnlyLocalEntities) {
  if (!OnlyLocalEntities)
    MaybeLoadPreallocatedEntities();
  
  return PreprocessedEntities.end();
}

PreprocessingRecord::const_iterator 
PreprocessingRecord::begin(bool OnlyLocalEntities) const {
  if (OnlyLocalEntities)
    return PreprocessedEntities.begin() + NumPreallocatedEntities;
  
  MaybeLoadPreallocatedEntities();
  return PreprocessedEntities.begin();
}

PreprocessingRecord::const_iterator 
PreprocessingRecord::end(bool OnlyLocalEntities) const {
  if (!OnlyLocalEntities)
    MaybeLoadPreallocatedEntities();
  
  return PreprocessedEntities.end();
}

void PreprocessingRecord::addPreprocessedEntity(PreprocessedEntity *Entity) {
  PreprocessedEntities.push_back(Entity);
}

void PreprocessingRecord::SetExternalSource(
                                    ExternalPreprocessingRecordSource &Source,
                                            unsigned NumPreallocatedEntities) {
  assert(!ExternalSource &&
         "Preprocessing record already has an external source");
  ExternalSource = &Source;
  this->NumPreallocatedEntities = NumPreallocatedEntities;
  PreprocessedEntities.insert(PreprocessedEntities.begin(), 
                              NumPreallocatedEntities, 0);
}

void PreprocessingRecord::SetPreallocatedEntity(unsigned Index, 
                                                PreprocessedEntity *Entity) {
  assert(Index < NumPreallocatedEntities &&"Out-of-bounds preallocated entity");
  PreprocessedEntities[Index] = Entity;
}

void PreprocessingRecord::RegisterMacroDefinition(MacroInfo *Macro, 
                                                  MacroDefinition *MD) {
  MacroDefinitions[Macro] = MD;
}

MacroDefinition *PreprocessingRecord::findMacroDefinition(const MacroInfo *MI) {
  llvm::DenseMap<const MacroInfo *, MacroDefinition *>::iterator Pos
    = MacroDefinitions.find(MI);
  if (Pos == MacroDefinitions.end())
    return 0;
  
  return Pos->second;
}

void PreprocessingRecord::MacroExpands(const Token &Id, const MacroInfo* MI) {
  if (MacroDefinition *Def = findMacroDefinition(MI))
    PreprocessedEntities.push_back(
                       new (*this) MacroInstantiation(Id.getIdentifierInfo(),
                                                      Id.getLocation(),
                                                      Def));
}

void PreprocessingRecord::MacroDefined(const IdentifierInfo *II, 
                                       const MacroInfo *MI) {
  SourceRange R(MI->getDefinitionLoc(), MI->getDefinitionEndLoc());
  MacroDefinition *Def
    = new (*this) MacroDefinition(II, MI->getDefinitionLoc(), R);
  MacroDefinitions[MI] = Def;
  PreprocessedEntities.push_back(Def);
}

void PreprocessingRecord::MacroUndefined(const IdentifierInfo *II, 
                                         const MacroInfo *MI) {
  llvm::DenseMap<const MacroInfo *, MacroDefinition *>::iterator Pos
    = MacroDefinitions.find(MI);
  if (Pos != MacroDefinitions.end())
    MacroDefinitions.erase(Pos);
}