//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// CodeGenerator2.cc -- 
//
// Author           : Richard C. Bilson
// Created On       : Mon May 18 07:44:20 2015
// Last Modified By : Peter A. Buhr
// Last Modified On : Thu May 21 17:13:35 2015
// Update Count     : 7
//

#include <algorithm>
#include <iostream>
#include <cassert>
#include <list>

#include "SynTree/Type.h"
#include "SynTree/Declaration.h"
#include "SynTree/Statement.h"
#include "SynTree/Expression.h"
#include "SynTree/Initializer.h"

#include "utility.h"
#include "UnimplementedError.h"

#include "CodeGenerator2.h"
#include "OperatorTable.h"
#include "GenType.h"

using namespace std;

namespace CodeGen {
	int CodeGenerator2::tabsize = 4;

	CodeGenerator2::CodeGenerator2( std::ostream &os ) : cur_indent( 0 ), insideFunction( false ), before( os ), after() { }

	CodeGenerator2::CodeGenerator2( std::ostream &os, std::string init, int indent, bool infunp )
		: cur_indent( indent ), insideFunction( infunp ), before( os ) {
		//before << std::string( init );
	}

	CodeGenerator2::CodeGenerator2( std::ostream &os, char *init, int indent, bool infunp )
		: cur_indent( indent ), insideFunction( infunp ), before( os ) {
		//before << std::string( init );
	}

	string mangleName( DeclarationWithType *decl ) {
		if ( decl->get_mangleName() != "" ) {
			return decl->get_mangleName();
		} else {
			return decl->get_name();
		} // if
	}
  
	//*** Declarations
	void CodeGenerator2::visit( FunctionDecl *functionDecl ) {
		handleStorageClass( functionDecl );
		before << genType( functionDecl->get_functionType(), mangleName( functionDecl ) );

		// how to get this to the Functype?
		std::list< Declaration * > olds = functionDecl->get_oldDecls();
		if ( ! olds.empty() ) {
			before << " /* function has old declaration */";
		} // if

		// acceptAll( functionDecl->get_oldDecls(), *this );
		if ( functionDecl->get_statements() ) {
			functionDecl->get_statements()->accept(*this );
		} // if
	}

	void CodeGenerator2::visit( ObjectDecl *objectDecl ) {
		handleStorageClass( objectDecl );
		before << genType( objectDecl->get_type(), mangleName( objectDecl ) );
	
		if ( objectDecl->get_init() ) {
			before << " = ";
			objectDecl->get_init()->accept( *this );
		} // if
		if ( objectDecl->get_bitfieldWidth() ) {
			before << ":";
			objectDecl->get_bitfieldWidth()->accept( *this );
		} // if
	}

	void CodeGenerator2::handleAggregate( AggregateDecl *aggDecl ) {
		if ( aggDecl->get_name() != "" )
			before << aggDecl->get_name();
	
		std::list< Declaration * > &memb = aggDecl->get_members();

		if ( ! memb.empty() ) {
			before << endl << string( cur_indent, ' ' ) << "{" << endl;

			cur_indent += CodeGenerator2::tabsize; 
			for ( std::list< Declaration* >::iterator i = memb.begin(); i != memb.end();  i++) {
				before << string( cur_indent, ' ' ); 
				(*i)->accept(*this );
				before << ";" << endl;
			}

			cur_indent -= CodeGenerator2::tabsize; 

			before << string( cur_indent, ' ' ) << "}";
		} // if
	}

	void CodeGenerator2::visit( StructDecl *structDecl ) {
		before << "struct ";
		handleAggregate( structDecl );
	}

	void CodeGenerator2::visit( UnionDecl *aggregateDecl ) {
		before << "union ";
		handleAggregate( aggregateDecl );
	}
  
	void CodeGenerator2::visit( EnumDecl *aggDecl ) {
		before << "enum ";

		if ( aggDecl->get_name() != "" )
			before << aggDecl->get_name();
	
		std::list< Declaration* > &memb = aggDecl->get_members();

		if ( ! memb.empty() ) {
			before << endl << "{" << endl;

			cur_indent += CodeGenerator2::tabsize; 
			for ( std::list< Declaration* >::iterator i = memb.begin(); i != memb.end();  i++) {
				ObjectDecl *obj = dynamic_cast< ObjectDecl* >( *i );
				assert( obj );
				before << string( cur_indent, ' ' ) << mangleName( obj ); 
				if ( obj->get_init() ) {
					before << " = ";
					obj->get_init()->accept(*this );
				} // if
				before << "," << endl;
			} // for

			cur_indent -= CodeGenerator2::tabsize; 

			before << "}" << endl;
		} // if
	}
  
	void CodeGenerator2::visit( ContextDecl *aggregateDecl ) {}
  
	void CodeGenerator2::visit( TypedefDecl *typeDecl ) {
		before << "typedef ";
		before << genType( typeDecl->get_base(), typeDecl->get_name() );
	}
  
	void CodeGenerator2::visit( TypeDecl *typeDecl ) {
		// really, we should mutate this into something that isn't a TypeDecl but that requires large-scale changes,
		// still to be done
		before << "extern unsigned long " << typeDecl->get_name();
		if ( typeDecl->get_base() ) {
			before << " = sizeof( " << genType( typeDecl->get_base(), "" ) << " )";
		} // if
	}

	void CodeGenerator2::visit( SingleInit *init ) {
		init->get_value()->accept( *this );
	}

	void CodeGenerator2::visit( ListInit *init ) {
		before << "{ ";
		genCommaList( init->begin_initializers(), init->end_initializers() );
		before << " }";
	}

	void CodeGenerator2::visit( Constant *constant ) { 
		before << constant->get_value() ;
	}

	//*** Expressions
	void CodeGenerator2::visit( ApplicationExpr *applicationExpr ) {
		if ( VariableExpr *varExpr = dynamic_cast< VariableExpr* >( applicationExpr->get_function() ) ) {
			OperatorInfo opInfo;
			if ( varExpr->get_var()->get_linkage() == LinkageSpec::Intrinsic && operatorLookup( varExpr->get_var()->get_name(), opInfo ) ) {
				std::list< Expression* >::iterator arg = applicationExpr->get_args().begin();
				switch ( opInfo.type ) {
				  case OT_PREFIXASSIGN:
				  case OT_POSTFIXASSIGN:
				  case OT_INFIXASSIGN:
					{
						assert( arg != applicationExpr->get_args().end() );
						if ( AddressExpr *addrExpr = dynamic_cast< AddressExpr * >( *arg ) ) {
	        
							*arg = addrExpr->get_arg();
						} else {
							UntypedExpr *newExpr = new UntypedExpr( new NameExpr( "*?" ) );
							newExpr->get_args().push_back( *arg );
							*arg = newExpr;
						} // if
						break;
					}
	      
				  default:
					// do nothing
					;
				}
	    
				switch ( opInfo.type ) {
				  case OT_INDEX:
					assert( applicationExpr->get_args().size() == 2 );
					(*arg++)->accept( *this );
					before << "[";
					(*arg)->accept( *this );
					before << "]";
					break;
	      
				  case OT_CALL:
					// there are no intrinsic definitions of the function call operator
					assert( false );
					break;
	      
				  case OT_PREFIX:
				  case OT_PREFIXASSIGN:
					assert( applicationExpr->get_args().size() == 1 );
					before << "(";
					before << opInfo.symbol;
					(*arg)->accept( *this );
					before << ")";
					break;
	      
				  case OT_POSTFIX:
				  case OT_POSTFIXASSIGN:
					assert( applicationExpr->get_args().size() == 1 );
					(*arg)->accept( *this );
					before << opInfo.symbol;
					break;

				  case OT_INFIX:
				  case OT_INFIXASSIGN:
					assert( applicationExpr->get_args().size() == 2 );
					before << "(";
					(*arg++)->accept( *this );
					before << opInfo.symbol;
					(*arg)->accept( *this );
					before << ")";
					break;
	      
				  case OT_CONSTANT:
					// there are no intrinsic definitions of 0 or 1 as functions
					assert( false );
				}
			} else {
				varExpr->accept( *this );
				before << "(";
				genCommaList( applicationExpr->get_args().begin(), applicationExpr->get_args().end() );
				before << ")";
			} // if
		} else {
			applicationExpr->get_function()->accept( *this );
			before << "(";
			genCommaList( applicationExpr->get_args().begin(), applicationExpr->get_args().end() );
			before << ")";
		} // if
	}
  
	void CodeGenerator2::visit( UntypedExpr *untypedExpr ) {
		if ( NameExpr *nameExpr = dynamic_cast< NameExpr* >( untypedExpr->get_function() ) ) {
			OperatorInfo opInfo;
			if ( operatorLookup( nameExpr->get_name(), opInfo ) ) {
				std::list< Expression* >::iterator arg = untypedExpr->get_args().begin();
				switch ( opInfo.type ) {
				  case OT_INDEX:
					assert( untypedExpr->get_args().size() == 2 );
					(*arg++)->accept( *this );
					before << "[";
					(*arg)->accept( *this );
					before << "]";
					break;
	      
				  case OT_CALL:
					assert( false );
					break;
	      
				  case OT_PREFIX:
				  case OT_PREFIXASSIGN:
					assert( untypedExpr->get_args().size() == 1 );
					before << "(";
					before << opInfo.symbol;
					(*arg)->accept( *this );
					before << ")";
					break;
	      
				  case OT_POSTFIX:
				  case OT_POSTFIXASSIGN:
					assert( untypedExpr->get_args().size() == 1 );
					(*arg)->accept( *this );
					before << opInfo.symbol;
					break;
  
				  case OT_INFIX:
				  case OT_INFIXASSIGN:
					assert( untypedExpr->get_args().size() == 2 );
					before << "(";
					(*arg++)->accept( *this );
					before << opInfo.symbol;
					(*arg)->accept( *this );
					before << ")";
					break;
	      
				  case OT_CONSTANT:
					// there are no intrinsic definitions of 0 or 1 as functions
					assert( false );
				}
			} else {
				nameExpr->accept( *this );
				before << "(";
				genCommaList( untypedExpr->get_args().begin(), untypedExpr->get_args().end() );
				before << ")";
			} // if
		} else {
			untypedExpr->get_function()->accept( *this );
			before << "(";
			genCommaList( untypedExpr->get_args().begin(), untypedExpr->get_args().end() );
			before << ")";
		} // if
	}
  
	void CodeGenerator2::visit( NameExpr *nameExpr ) {
		OperatorInfo opInfo;
		if ( operatorLookup( nameExpr->get_name(), opInfo ) ) {
			assert( opInfo.type == OT_CONSTANT );
			before << opInfo.symbol;
		} else {
			before << nameExpr->get_name();
		} // if
	}
  
	void CodeGenerator2::visit( AddressExpr *addressExpr ) {
		before << "(&";
		// this hack makes sure that we don't convert "constant_zero" to "0" if we're taking its address
		if ( VariableExpr *variableExpr = dynamic_cast< VariableExpr* >( addressExpr->get_arg() ) ) {
			before << mangleName( variableExpr->get_var() );
		} else {
			addressExpr->get_arg()->accept( *this );
		} // if
		before << ")";
	}

	void CodeGenerator2::visit( CastExpr *castExpr ) {
		before << "((";
		if ( castExpr->get_results().empty() ) {
			before << "void" ;
		} else {
			before << genType( castExpr->get_results().front(), "" );
		} // if
		before << ")";
		castExpr->get_arg()->accept( *this );
		before << ")";
	}
  
	void CodeGenerator2::visit( UntypedMemberExpr *memberExpr ) {
		assert( false );
	}
  
	void CodeGenerator2::visit( MemberExpr *memberExpr ) {
		memberExpr->get_aggregate()->accept( *this );
		before << "." << mangleName( memberExpr->get_member() );
	}
  
	void CodeGenerator2::visit( VariableExpr *variableExpr ) {
		OperatorInfo opInfo;
		if ( variableExpr->get_var()->get_linkage() == LinkageSpec::Intrinsic && operatorLookup( variableExpr->get_var()->get_name(), opInfo ) && opInfo.type == OT_CONSTANT ) {
			before << opInfo.symbol;
		} else {
			before << mangleName( variableExpr->get_var() );
		} // if
	}
  
	void CodeGenerator2::visit( ConstantExpr *constantExpr ) {
		assert( constantExpr->get_constant() );
		constantExpr->get_constant()->accept( *this );
	}
  
	void CodeGenerator2::visit( SizeofExpr *sizeofExpr ) {
		before << "sizeof(";
		if ( sizeofExpr->get_isType() ) {
			before << genType( sizeofExpr->get_type(), "" );
		} else {
			sizeofExpr->get_expr()->accept( *this );
		} // if
		before << ")";
	}
  
	void CodeGenerator2::visit( LogicalExpr *logicalExpr ) {
		before << "(";
		logicalExpr->get_arg1()->accept( *this );
		if ( logicalExpr->get_isAnd() ) {
			before << " && ";
		} else {
			before << " || ";
		} // if
		logicalExpr->get_arg2()->accept( *this );
		before << ")";
	}
  
	void CodeGenerator2::visit( ConditionalExpr *conditionalExpr ) {
		before << "(";
		conditionalExpr->get_arg1()->accept( *this );
		before << " ? ";
		conditionalExpr->get_arg2()->accept( *this );
		before << " : ";
		conditionalExpr->get_arg3()->accept( *this );
		before << ")";
	}
  
	void CodeGenerator2::visit( CommaExpr *commaExpr ) {
		before << "(";
		commaExpr->get_arg1()->accept( *this );
		before << " , ";
		commaExpr->get_arg2()->accept( *this );
		before << ")";
	}
  
	void CodeGenerator2::visit( TupleExpr *tupleExpr ) {}
  
	void CodeGenerator2::visit( TypeExpr *typeExpr ) {}
  
  
	//*** Statements
	void CodeGenerator2::visit( CompoundStmt *compoundStmt ) {
		std::list<Statement*> ks = compoundStmt->get_kids();

		before << endl << string( cur_indent, ' ' ) << "{" << endl;

		cur_indent += CodeGenerator2::tabsize; 

		for ( std::list<Statement *>::iterator i = ks.begin(); i != ks.end();  i++) {
			before << string( cur_indent, ' ' ) << printLabels( (*i)->get_labels() )  ;
			(*i)->accept(*this );
			shift_left();
			before << endl;
		}
		cur_indent -= CodeGenerator2::tabsize; 

		before << string( cur_indent, ' ' ) << "}" << endl;
	}

	void CodeGenerator2::visit( ExprStmt *exprStmt ) {
		if ( exprStmt != 0 ) {
			exprStmt->get_expr()->accept( *this );
			shift_left();
			before << ";" ;
		} // if
	}

	void CodeGenerator2::visit( IfStmt *ifStmt ) {
		before << "if (";
		ifStmt->get_condition()->accept(*this );
		after += ")\n";
		shift_left(); 

		cur_indent += CodeGenerator2::tabsize;
		before << string( cur_indent, ' ' );
		ifStmt->get_thenPart()->accept(*this );
		cur_indent -= CodeGenerator2::tabsize; 
		shift_left(); before << endl;

		if ( ifStmt->get_elsePart() != 0) {
			before << string( cur_indent, ' ' ) << " else " << endl ;

			cur_indent += CodeGenerator2::tabsize; 
			ifStmt->get_elsePart()->accept(*this );
			cur_indent -= CodeGenerator2::tabsize; 
		} // if
	}

	void CodeGenerator2::visit( SwitchStmt *switchStmt ) {
		//before << /* "\r" << */ string( cur_indent, ' ' ) << CodeGenerator2::printLabels( switchStmt->get_labels() ) 
		before << "switch (" ;
		switchStmt->get_condition()->accept(*this );
		after += ")\n";
		shift_left();

		before << string( cur_indent, ' ' ) << "{" << std::endl;
		cur_indent += CodeGenerator2::tabsize;

		std::list< Statement * > stmts = switchStmt->get_branches();
		bool lastBreak = false; 

		// horrible, horrible hack
		if ( dynamic_cast<BranchStmt *>( stmts.back() ) != 0 ) {
			lastBreak = true;
			stmts.pop_back();
		} // if
		acceptAll( stmts, *this );
		if ( lastBreak ) {
			Statement *st = switchStmt->get_branches().back();
			before << CodeGenerator2::printLabels( st->get_labels());
			st->accept( *this );
		} // if
	  
		cur_indent -= CodeGenerator2::tabsize; 

		before << /* "\r" << */ string( cur_indent, ' ' ) << "}" << endl ;
	}

	void CodeGenerator2::visit( CaseStmt *caseStmt ) {
		before << string( cur_indent, ' ' );
		if ( caseStmt->isDefault()) 
			before << "default "  ;
		else {
			before << "case "  ;
			caseStmt->get_condition()->accept(*this );
		} // if
		after += ":\n";
		shift_left();

		std::list<Statement *> sts = caseStmt->get_statements();

		cur_indent += CodeGenerator2::tabsize;
		for ( std::list<Statement *>::iterator i = sts.begin(); i != sts.end();  i++) {
			before << /* "\r" << */ string( cur_indent, ' ' ) << printLabels( (*i)->get_labels() )  ;
			(*i)->accept(*this );
			shift_left();
			before << ";" << endl;
		}
		cur_indent -= CodeGenerator2::tabsize;
	}

	void CodeGenerator2::visit( BranchStmt *branchStmt ) {
		switch ( branchStmt->get_type()) {
		  case BranchStmt::Goto:
			if ( ! branchStmt->get_target().empty() )
				before << "goto " << branchStmt->get_target();
			else { 
				if ( branchStmt->get_computedTarget() != 0 ) {
					before << "goto *";
					branchStmt->get_computedTarget()->accept( *this );
				} // if
			} // if
			break;
		  case BranchStmt::Break:
			before << "break";
			break;
		  case BranchStmt::Continue:
			before << "continue";
			break;
		}
		before << ";";
	}


	void CodeGenerator2::visit( ReturnStmt *returnStmt ) {
		before << "return ";

		// xxx -- check for null expression;
		if ( returnStmt->get_expr() ) {
			returnStmt->get_expr()->accept( *this );
		} // if
		after += ";";
	}

	void CodeGenerator2::visit( WhileStmt *whileStmt ) {
		if ( whileStmt->get_isDoWhile() )
			before << "do" ;
		else {
			before << "while (" ;
			whileStmt->get_condition()->accept(*this );
			after += ")";
		} // if
		after += "{\n";
		shift_left();

		whileStmt->get_body()->accept( *this );

		before << /* "\r" << */ string( cur_indent, ' ' ) << "}" ;

		if ( whileStmt->get_isDoWhile() ) {
			before << " while (" ;
			whileStmt->get_condition()->accept(*this );
			after += ");";
		} // if

		after += "\n";
	}

	void CodeGenerator2::visit( ForStmt *forStmt ) {
		before << "for (";

		if ( forStmt->get_initialization() != 0 )
			forStmt->get_initialization()->accept( *this );
		else
			before << ";";
		shift_left();

		if ( forStmt->get_condition() != 0 )
			forStmt->get_condition()->accept( *this );
		shift_left(); before << ";";

		if ( forStmt->get_increment() != 0 )
			forStmt->get_increment()->accept( *this );
		shift_left(); before << ")" << endl;

		if ( forStmt->get_body() != 0 ) {
			cur_indent += CodeGenerator2::tabsize; 
			before << string( cur_indent, ' ' ) << CodeGenerator2::printLabels( forStmt->get_body()->get_labels() );
			forStmt->get_body()->accept( *this );
			cur_indent -= CodeGenerator2::tabsize; 
		} // if
	}

	void CodeGenerator2::visit( NullStmt *nullStmt ) {
		//before << /* "\r" << */ string( cur_indent, ' ' ) << CodeGenerator2::printLabels( nullStmt->get_labels() );
		before << "/* null statement */ ;";
	}

	void CodeGenerator2::visit( DeclStmt *declStmt ) {
		declStmt->get_decl()->accept( *this );
	
		if ( doSemicolon( declStmt->get_decl() ) ) {
			after += ";";
		} // if
		shift_left();
	}

	std::string CodeGenerator2::printLabels( std::list< Label > &l ) {
		std::string str( "" );
		l.unique();

		for ( std::list< Label >::iterator i = l.begin(); i != l.end(); i++ )
			str += *i + ": ";

		return str;
	}

	void CodeGenerator2::shift_left() {
		before << after;
		after = "";
	}

	void CodeGenerator2::handleStorageClass( Declaration *decl ) {
		switch ( decl->get_storageClass() ) {
		  case Declaration::NoStorageClass:
			break;
		  case Declaration::Extern:
			before << "extern ";
			break;
		  case Declaration::Static:
			before << "static ";
			break;
		  case Declaration::Auto:
			// silently drop storage class
			break;
		  case Declaration::Register:
			before << "register ";
			break;
		} // switch
	}
} // namespace CodeGen

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //