Method ParseForStatement

neo/d3xp/script/Script_Compiler.cpp:1825–1890

================ idCompiler::ParseForStatement Form of for statement with a counter: a = 0; start: << patch4 if ( !( a < 10 ) ) { goto end; << patch1 } else { goto process; << patch3 } increment: << patch2 a = a + 1; goto start; << goto patch4 process: statements; goto increment; << goto patch2 end: Form of for statement without a counter: a = 0; start: << patch2

================
*/
void idCompiler::ParseForStatement( void ) {
	idVarDef	*e;
	int			start;
	int			patch1;
	int			patch2;
	int			patch3;
	int			patch4;

	loopDepth++;

	start = gameLocal.program.NumStatements();

	ExpectToken( "(" );

	// init
	if ( !CheckToken( ";" ) ) {
		do {
			GetExpression( TOP_PRIORITY );
		} while( CheckToken( "," ) );

		ExpectToken( ";" );
	}

	// condition
	patch2 = gameLocal.program.NumStatements();

	e = GetExpression( TOP_PRIORITY );
	ExpectToken( ";" );

	//FIXME: add check for constant expression
	patch1 = gameLocal.program.NumStatements();
	EmitOpcode( OP_IFNOT, e, 0 );

	// counter
	if ( !CheckToken( ")" ) ) {
		patch3 = gameLocal.program.NumStatements();
		EmitOpcode( OP_IF, e, 0 );

		patch4 = patch2;
		patch2 = gameLocal.program.NumStatements();
		do {
			GetExpression( TOP_PRIORITY );
		} while( CheckToken( "," ) );

		ExpectToken( ")" );

		// goto patch4
		EmitOpcode( OP_GOTO, JumpTo( patch4 ), 0 );

		// fixup patch3
		gameLocal.program.GetStatement( patch3 ).b = JumpFrom( patch3 );
	}

	ParseStatement();

	// goto patch2
	EmitOpcode( OP_GOTO, JumpTo( patch2 ), 0 );