and look at the description at the top. Here's an intro.
This patch makes significant changes to the configure script. It adds the
lines AC_CANONICAL_HOST and AC_CANONICAL_TARGET which detect the OS and
processor type. The configure script, knowing the OS and processor type, can
then make intelligent decisions about which CFLAGS are needed and what is the
default GUI for that platform. One of the goals of this patch is to make it
so that on all supported platforms, "configure;make" will compile cleanly.
Configure detects the target platform, but it can be overridden by using
--target=___. This is important when using one platform to generate
Makefiles and header files for another platform. See config.guess script for
the exact details of platform naming.
The defaults that are currently implemented in the modified configure script
include:
If platform is windows* or winnt*, use win32 gui.
If platform is cygwin*, use win32 gui and compile with
"-mno-cygwin -DWIN32".
If platform is macosx* or darwin*, use carbon gui and compile
with "-fpascal-strings -fno-common -arch ppc -Wno-four-char-constants
-Wno-unknown-pragmas -Dmacintosh"
If platform is macos, use macos gui.
If platform is beos, use beos gui.
If platform is amigaos, use amigaos gui.
Otherwise, use X windows gui.
