Compila17 compiler

Contributors

• oddgfa - Odd Gunnar Fatland
• pavelju - Pavel Jurasek
• salihasa - Saliha Sajid

Usage

Build using ant build and run using ant run.

## Design We divided the nodes into three main parts: expressions, statements and declarations. The structure can be seen in the picture below. ![AST design][ast]

Solution methods

For writing the ambiguous grammar, we defined precedences of the operators. We reduced expressions into unary and binary and then binary expressions eventually into Logical Operator Expressions, Arithmetic Operator Expressions and Relational Operator Expressions. The operations were then applied to the input as per precedences.

For writing the unambiguous grammar we declared the operators as Strings. We created an unambiguous set of productions starting from unary expressions to parse an input file such that the operators with highest precedence are applied before others. There were some conflicts in unambiguous grammar but those were resolved by indication of the expression to be parsed first.

## AST from Compila.cmp ```` (PROGRAM (NAME ComplexAddition) (CLASS_DECL (NAME Complex) (VAR_DECL (TYPE float) (NAME Real)) (VAR_DECL (TYPE float) (NAME Imag)) ) (PROC_DECL (NAME Swap) (PARAM_DECL (TYPE (REF int)) (NAME a)) (PARAM_DECL (TYPE (REF int)) (NAME b))

	(VAR_DECL (TYPE int) (NAME tmp))

	(ASSIGN_STMT
		(NAME tmp)
		(DEREF (NAME a))
	)
	(ASSIGN_STMT
		(DEREF (NAME a))
		(DEREF (NAME b))
	)
	(ASSIGN_STMT
		(DEREF (NAME b))
		(NAME tmp)
	)
)
(PROC_DECL (TYPE Complex) (NAME Add)
	(PARAM_DECL (TYPE Complex) (NAME a))
	(PARAM_DECL (TYPE Complex) (NAME b))

	(VAR_DECL (TYPE Complex) (NAME retval))

	(ASSIGN_STMT
		(NAME retval)
		(NEW (TYPE Complex))
	)
	(ASSIGN_STMT
		( . (NAME retval) (NAME Real))
		(ARIT_OP +
			( . (NAME a) (NAME Real))
			( . (NAME b) (NAME Real))
		)
	)
	(ASSIGN_STMT
		( . (NAME retval) (NAME Imag))
		(ARIT_OP +
			( . (NAME a) (NAME Imag))
			( . (NAME b) (NAME Imag))
		)
	)
	(RETURN_STMT (NAME retval))

)
(PROC_DECL (TYPE int) (NAME Max)
	(PARAM_DECL (TYPE int) (NAME a))
	(PARAM_DECL (TYPE int) (NAME b))

	(IF_STMT
		(REL_OP >
			(NAME a)
			(NAME b)
		)
		(
			(RETURN_STMT (NAME a))
		)
	)

	(RETURN_STMT (NAME b))

)
(PROC_DECL (NAME Main)
	(PROC_DECL (TYPE float) (NAME Square)
		(PARAM_DECL (TYPE float) (NAME val))

		(RETURN_STMT (ARIT_OP #
			(NAME val)
			(FLOAT_LITERAL 2.0)
		))

	)
	(VAR_DECL (TYPE float) (NAME num))

	(ASSIGN_STMT
		(NAME num)
		(FLOAT_LITERAL 6.48074)
	)
	(CALL_STMT (NAME print_float)
		(NAME num)
	)

	(CALL_STMT (NAME print_str)
		(STRING_LITERAL " squared is ")
	)

	(CALL_STMT (NAME print_float)
		(CALL_STMT (NAME Square)
			(NAME num)
		)

	)

	(RETURN_STMT)

)

)

[ast]: https://scontent.flcy1-1.fna.fbcdn.net/v/t1.0-9/16998786_10202854026549374_6172743699134968588_n.jpg?oh=f6c5e250667e3a884c631beabfb0c223&oe=59287E53