Autoconf and Makefile variables

Throught the project autoconf is used and here is a brief explanation of some of the autoconf macros.
(cd $(SOME_DIR2); rm -rf config.cache; $(TARGET_CONFIGURE_OPTS) CFLAGS="$(TARGET_CFLAGS)" CPPFLAGS="$(SED_CFLAGS)" ./configure --target=$(GNU_TARGET_NAME) --host=$(GNU_TARGET_NAME) --build=$(GNU_HOST_NAME) --prefix=/usr );
The macros are defined in the file Virutual.mk and are the following
ARCH:=i386
OPTIMIZE_FOR_CPU=$(ARCH)
GNU_TARGET_NAME=$(OPTIMIZE_FOR_CPU)-linux
GNU_HOST_NAME:=$(HOST_ARCH)-pc-linux-gnu

the following triplet will be defined throughout the buid process:

--target=$(GNU_TARGET_NAME)
--host=$(GNU_TARGET_NAME)
--build=$(GNU_HOST_NAME)

and are infact called a configuration triplet and are as follows cpu-manufacturer-operating_system.