configure.info: Build and Host Options
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Build and Host Options
When you run `configure', you must use both the `--build' and
`--host' options.
The `--build' option is used to specify the configuration name of
the build system. This can normally be the result of running the
`config.guess' shell script, and it is reasonable to use
`--build=`config.guess`'.
The `--host' option is used to specify the configuration name of the
host system.
As we explained earlier, `config.guess' is used to set the default
value for the `--host' option (*note Using the Host Type::). We can
now see that since `config.guess' returns the type of system on which
it is run, it really identifies the build system. Since the host
system is normally the same as the build system (i.e., people do not
normally build using a cross compiler), it is reasonable to use the
result of `config.guess' as the default for the host system when the
`--host' option is not used.
It might seem that if the `--host' option were used without the
`--build' option that the configure script could run `config.guess' to
determine the build system, and presume a Canadian Cross if the result
of `config.guess' differed from the `--host' option. However, for
historical reasons, some configure scripts are routinely run using an
explicit `--host' option, rather than using the default from
`config.guess'. As noted earlier, it is difficult or impossible to
reliably compare configuration names (*note Using the Target Type::).
Therefore, by convention, if the `--host' option is used, but the
`--build' option is not used, then the build system defaults to the
host system.
Created Wed Sep 1 16:42:00 2004 on bee with info_to_html version 0.9.6.