Gnu make source code

[Mohamed Horani]

Hey i'm working in a graduation project is about modifying Gnu make package

Anyway i'm studying the Code right now .. But it seems more complex to
understand

so i really need help...

i couldn't determine the beginning and the end of the source file so it was
a bad start for me.
i wanna a clue how to start reading the source package of GNU Make ?!

Second i noticed the source package written in multi-programming language
e.g. m4 files something looks like that

isnt it written purely in C programming language ?!

Third there is an option -j so i can compile most of  packages in parallel ?

Where i can find the -j option code in the source file ?!

Thanks in Advance