How to compile Calc

Hi,
I have check out a new copy of calc libreoffice-3-4 project and have no
clue on how to compile it.

There are 4 sub project inside calc project. May I know how should I
compile in order to have the calc program up?

There are Makefile inside each project, when trying to compile it, I hit
this error:
Makefile:25: *** No environment set!.  Stop.

When searching inside the Makefile, I got this variable $(SOLARENV), I have
no clue how to resolve this variable, hope you guys can help.

THanks @!