Diff Checker Code Comments

Introduction

This repository contains the scripts to remove comments - single line and multi-line comments written in the javadoc style

Javadoc comments are written in the following format:

    /**
    * Returns an Image object that can then be painted on the screen. 
    * The url argument must specify an absolute <a href="#{@link}">{@link URL}</a>. The name
    * argument is a specifier that is relative to the url argument. 
    * <p>
    * This method always returns immediately, whether or not the 
    * image exists. When this applet attempts to draw the image on
    * the screen, the data will be loaded. The graphics primitives 
    * that draw the image will incrementally paint on the screen. 
    *
    * @param  url  an absolute URL giving the base location of the image
    * @param  name the location of the image, relative to the url argument
    * @return      the image at the specified URL
    * @see         Image
    */

    public Image getImage(URL url, String name) {
        try {
            return getImage(new URL(url, name));
        } catch (MalformedURLException e) {
            return null;
        }
    }

This style is used to write API documentation

Use case

During the course of my GSoD project, I have been writing API documentation for C/C++ code using the documentation generator Doxygen

To avoid the possibility that the source code may be modified in the process of doing so, I created a script written in lex that can be used to remove comments from the source code. A diff of the 2 files can be performed to ensure the integrity of the source code

Usage

1. Install lex/flex. Lex is the lexical analyser that parses the input source code and tokenises it

2. Execute lex remove_comments.l. This produces a file lex.yy.c. Read more about what a lexical analyser does here

3. Execute cc lex.yy.c, this generates the executable a.out, like any other C program

4. Run ./a.out <source-file> <target-file>, where <source file> is the file with comments and <target file> is a new file without comments

Example

1. Consider a sample file input.cpp with the contents

/** 
 * This is a sample input which javadoc style comments 
 */
#include<stdio.h>

int main(){
	/**
	 * Performs the addition of 3 and 5
	 */
	printf("The sum of 3 and 5 is %d\n", 3+5);
	return 0;
}

2. On executing the above-mentioned commands, the output is in file output.cpp

#include<stdio.h>

int main(){
	

	printf("The sum of 3 and 5 is d\n", 3+5);
	return 0;
}

The output has newlines which can be removed during further preprocessing