11.3 Using the System Type

How do you use a canonical system type? Usually, you use it in one or more case statements in `configure.ac' to select system-specific C files. Then, using AC_CONFIG_LINKS, link those files which have names based on the system name, to generic names, such as `host.h' or `target.c' (see section 4.10 Creating Configuration Links). The case statement patterns can use shell wild cards to group several cases together, like in this fragment:

case "$target" in i386-*-mach* | i386-*-gnu*) obj_format=aout emulation=mach bfd_gas=yes ;; i960-*-bout) obj_format=bout ;; esac

and in `configure.ac', use:

AC_CONFIG_LINKS(host.h:config/$machine.h object.h:config/$obj_format.h)

You can also use the host system type to find cross-compilation tools. See section 5.2.2 Generic Program and File Checks, for information about the AC_CHECK_TOOL macro which does that.