#include <cstddef>
#include "AST.h"
#include "CfSource.h"
#include "CodeContext.h"
#include "compiler.h"
#include "parse.h"


const int CodeContext::recoverSlot = ios::xalloc();

void CodeContext::declare( const string &name, const CtType &type) {
  if (&whereDeclare == this)
    LocalVars::declare(name, type);
  else
    whereDeclare.declare(name, type);
}


inline CodeContext *CodeContext::recover( ostream &out )
{
  void * const pointer = out.pword( recoverSlot );
  return static_cast< CodeContext * >( pointer );    
}


void CodeContext::emitLineFileDirective( const SourcePosn &position, ostream &sink ) const
{
  if (!suppress_directives && position.known())
    sink << "#line " << position.posnToLineNumber()
	 << " \"" << *position.file << "\"\n";
}


void CodeContext::emitLineDirective( const SourcePosn &position, ostream &sink ) const
{
  if (!suppress_directives && position.known())
    sink << "#line " << position.posnToLineNumber() << '\n';
}


ostream &endCline( ostream &outs )
{
  outs << '\n';
  CodeContext *context = CodeContext::recover( outs );
  if (context == NULL) {
    cerr << "Internal Error: tried to use endCline outside any CodeContext" << endl;
    abort();
  }
  context->emitLineDirective( context->currentPosition, *context );
  return outs;
}


CodeContext::CodeContext( CodeContext &parent, ostream &sink )
  : LocalVars( parent ),
    strings( parent.strings ),
    sink( sink ),
    parent( &parent ),
    whereDeclare( *this ),
    currentPosition( parent.currentPosition ),
    startPosition( parent.currentPosition ),
    level( parent.level + 1 ),
    suppress_directives( !line_directives )
{
  pword( recoverSlot ) = this;
}


CodeContext::CodeContext( CodeContext &parent )
  : LocalVars( parent ),
    strings( parent.strings ),
    sink( parent ),
    parent( &parent ),
    whereDeclare( *this ),
    currentPosition( parent.currentPosition ),
    startPosition( parent.currentPosition ),
    level( parent.level + 1 ),
    suppress_directives( !line_directives )
{
  pword( recoverSlot ) = this;
}


CodeContext::CodeContext( CodeContext &parent, CodeContext &whereDeclare )
  : LocalVars( parent ),
    strings( parent.strings ),
    sink( parent ),
    parent( &parent ),
    whereDeclare( whereDeclare ),
    currentPosition( parent.currentPosition ),
    startPosition( parent.currentPosition ),
    level( parent.level + 1 ),
    suppress_directives( !line_directives )
{
  pword( recoverSlot ) = this;
}

CodeContext::CodeContext( CodeContext &parent, CodeContext *w )
  : LocalVars( parent ),
    strings( parent.strings ),
    sink( parent ),
    parent( &parent ),
    whereDeclare( w == NULL ? *this : *w ),
    currentPosition( parent.currentPosition ),
    startPosition( parent.currentPosition ),
    level( parent.level + 1 ),
    suppress_directives( !line_directives )
{
  pword( recoverSlot ) = this;
}


CodeContext::CodeContext( CfSource &file )
  : LocalVars( file ),
    strings( file ),
    sink( file ),
    parent( 0 ),
    whereDeclare( *this ),
    currentPosition( NoSourcePosition ),
    startPosition( NoSourcePosition ),
    level( 0 ),
    suppress_directives( !line_directives )
{
  pword( recoverSlot ) = this;
}


CodeContext::~CodeContext()
{
  codeGen();

  if (parent)
    {
      /* Set parent line information to the start of this context.
	 This is done in case the parent start_debug_{line,file}
	 information has not been filed yet. */
      parent->setPosition( startPosition );
    
      /* Set parent line information to the end of this context, so
	 that the parent can continue where this context left off. */
      parent->setPosition( currentPosition );
    }
}


void CodeContext::codeGen( ostream &sink ) const
{
  emitLineFileDirective( startPosition, sink );
  sink << "{/*L:" << level << "*/\n";
  emitLineDirective( startPosition, sink );

  LocalVars::codeGen( sink, suppress_directives ? 0 : startPosition.posnToLineNumber() );

  sink << str()
       << "}/*L:" << level << "*/\n";
  if (startPosition.file == currentPosition.file)
    emitLineDirective( currentPosition, sink );
  else
    emitLineFileDirective( currentPosition, sink );
}


void CodeContext::setPosition( const SourcePosn &newPosition )
{
  if (newPosition.known())
    {
      if (newPosition.file == currentPosition.file)
	if (newPosition.posnToLineNumber() == currentPosition.posnToLineNumber())
	  // same file, same line
	  ;
	else
	  // same file, different line
	  emitLineDirective( newPosition, *this );
      else
	// different file, different line
	emitLineFileDirective( newPosition, *this );
      
      currentPosition = newPosition;
      if (startPosition.unknown())
	startPosition = newPosition;
    }
}