compiler_design

This is basically a java compiler which checks the grammer of a java code i.e. it's token sequence, checks scope of a variable and produces intermediate code in TAC(three address code) format.

A1 Lexical analyser

checks grammer of the input code i.e. token sequence.

The grammer used in this code is simpler then the standard grammer of java program.

(<identifier> <identifier>)*
(<identifier> <compstat> <identifier>)*

%where compstat = "<" | ">" | "=".

A2 Syntax analyser

Checks whether the assignment statements written in the code are valid or not. For instance are we writing code like this

int a="string";

or

int a;

a={1,2,3};

It reports error on such code input.

A3 Intermediate code generator

Produces intermediate code int TAC(three address code) format of a given code.

For instance

input code=

int a=b+c+d;

output code=

int temp_var1=b+c;

int temp_var2=temp_var1+d;

int a=temp_var2;

A4 Scope analyser

Prints all the variables in a given scope.

For instance

input code=

.

.

.

.

.

printvars();

output code=

a b c d ....

% where a b c d... are variables that are accessible in the given scope.