How to modify the postgresql source code and build it?

Hello,
I need to initialize the db as the root and start the database server. In
order to accomplish this, I modified the initdb.c source file of pgsql
package and tried to compile it. Eventhough the build was successful, I
couldn't see the root user able to execute initdb executable generated by
the build. I wanted to know if there is any other procedure for building
the postgresql procedure?

Thanks
Shreesha.

P.S
Below is the changes done in initdb.c (shown in bold letters below)
-------------------------------------------------------------------------------------------------------------------------------
static char *
get_id(void)
{
#ifndef WIN32

struct passwd *pw;

// if (geteuid() == 0) /* 0 is root's uid */
*/* {*
* fprintf(stderr,*
* _("%s: cannot be run as root\n"*
* "Please log in (using, e.g., \"su\") as
the "*
* "(unprivileged) user that will\n"*
* "own the server process.\n"),*
* progname);*
* exit(1);*
* }*
**/*
...
}