##
2.4.8 VPATH feature

SDCC supports the VPATH feature provided by configure and make. It allows to separate the source and build trees. Here's an example:

cd ~ # cd $HOME

tar -xjf sdcc-src-yyyymmdd-rrrr.tar.bz2 # extract source to directory sdcc

mkdir sdcc.build # put output in sdcc.build

cd sdcc.build

../sdcc/configure # configure is doing all the magic!

make

That's it! configure will create the directory tree will all the necessary Makefiles in ~/sdcc.build. It automagically computes the variables srcdir, top_srcdir and top_buildir for each directory. After running make the generated files will be in ~/sdcc.build, while the source files stay in ~/sdcc.
This is not only usefull for building different binaries, e.g. when cross compiling. It also gives you a much better overview in the source tree when all the generated files are not scattered between the source files. And the best thing is: if you want to change a file you can leave the original file untouched in the source directory. Simply copy it to the build directory, edit it, enter `make clean', `rm Makefile.dep' and `make'. make will do the rest for you!