📟 Small Top-Down Compiler written in C

##About this Project

This project progressively builds up a small compiler for the below given CFG tools using the following technologies :

• C
• LEX
• YACC

##Context - Free Grammar

• [program] ==> class Program { [field_decl]* [method_decl]* }
• [field_decl] ==> [type] (id | id [ int_literal ] ) ( , id | id [ int-literal ] )* ;
• [field_decl] ==> [type] [id] = [constant] ;
• [method_decl] ==> { [type] | void } [id] (( ([type] [id]) ( , [type] [id])*)? ) [block]
• [block] ==> { [var_decl]* [statement]* }
• [var_decl] ==> [type] [id] ( , [id])* ;
• [type] ==> int | boolean
• [statement] ==> [location] [assign_op] [expr] ;
• [statement] ==> [method_call] ;
• [statement] ==> if ( [expr] ) [block] ( else [block] )?
• [statement] ==> for [id] = [expr] , [expr] [block]
• [statement] ==> return ( [expr] )? ;
• [statement] ==> break ;
• [statement] ==> continue ;
• [statement] ==> [block]
• [assign_op] ==> =
• [assign_op] ==> +=
• [assign_op] ==> -=
• [method_call] ==> [method_name] ( ([expr] ( , [expr] )*)? )
• [method_call] ==> callout ( [string_literal] ( , [callout_arg] )* )
• [method_name] ==> [id]
• [location] ==> [id]
• [location] ==> id [ expr ]
• [expr] ==> [location]
• [expr] ==> [method_call]
• [expr] ==> [literal]
• [expr] ==> '[expr] [bin_op] [expr]
• [expr] ==> - [expr]
• [expr] ==> ! [expr]
• [expr] ==> ( [expr] )
• [callout_arg] ==> [expr] | [string_literal]
• [bin_op] ==> [arith_op] | [rel_op] | [eq_op] | [cond_op]
• [arith_op] ==> + | - | * | / | %
• [rel_op] ==> < | > | <= | >=
• [eq_op] ==> == | !=
• [cond_op] -> && | ||
• [literal] ==> [int_literal] | [char_literal] | [bool_literal]
• [id] ==> [alpha] [alpha_num]*
• [alpha] ==> [a-zA-Z_]
• [alpha_num] ==> [alpha] | [digit]
• [digit] ==> [0-9]
• [hex_digit] ==> [digit] | [a-fA-F]
• [int_literal] ==> [decimal_literal] | [hex_literal]
• [decimal_literal] ==> [digit] [digit]*
• [hex_literal] ==> 0x [hex_digit] [hex_digit]*
• [bool_literal] ==> true | false
• [char_literal] ==> ‘[char]’
• [string_literal] ==> “[char]*”

##Features :

• Written in vanilla C
• Code is highly Modularized
• Abstraction Maintained
• Readability due to inline comments

How to Use The Code From source ?

$ git clone --recursive git@github.com:jainpranav/SmallCompiler.git

Contributing

Bug Reports & Feature Requests

Please use the issue tracker to report any bugs or file feature requests