Next: , Previous: Target Macros, Up: Top

18 Host Configuration

Most details about the machine and system on which the compiler is actually running are detected by the configure script. Some things are impossible for configure to detect; these are described in two ways, either by macros defined in a file named xm-machine.h or by hook functions in the file specified by the out_host_hook_obj variable in config.gcc. (The intention is that very few hosts will need a header file but nearly every fully supported host will need to override some hooks.)

If you need to define only a few macros, and they have simple definitions, consider using the xm_defines variable in your config.gcc entry instead of creating a host configuration header. See System Config.