Creating build hosts files

The build hosts file is the client-side control file for parallel builds.

Build hosts files that you specify by using the CCASE_HOST_TYPE environment variable must be located in your home directory, and each file must have a name that begins with .bldhost. Choose a file name extension for each build hosts file that describes its intended use. For example:

.bldhost.day

List of hosts used to perform parallel builds during the workday

.bldhost.night

List of hosts used to perform overnight parallel builds

Build hosts files that you specify with the -B option can be located anywhere and do not have to have special names.

Your build environment determines whether you need multiple build hosts files. In a heterogeneous network, for example, architecture-specific builds might or might not need to be performed on hosts of that architecture. (You might have cross-compilers, which eliminates this restriction.)

When you start a parallel build, you can specify a certain build hosts file or have clearmake select one by using the -B option. If you do not specify -B when running a parallel build, clearmake does the following:

1. Determines the host type.
2. Looks in the password database to determine your home directory.
3. Uses the file .bldhost.$CCASE_HOST_TYPE in your home directory.

For example, you can set up two build hosts files, for daytime and nighttime use, as follows:

1. Create a build hosts file for daytime use. For daytime builds, you can use the list of hosts that your system administrator has provided in /usr/local/lib, along with your own host. To minimize the disruption to other work, you can specify that each host is to be used only if it is not heavily loaded, that is, if it is at least 75% idle.

   % cat > $HOME/.bldhost.day
   -idle 75
   neptune
   #include /usr/local/lib/day_builds
   <CTRL+D>

2. Create a build hosts file for overnight use. For overnight builds, you can use another list of hosts provided by the system administrator.

   % cat > $HOME/.bldhost.night
   #include /usr/local/lib/night_builds
   <CTRL+D>

   Because this file does not include an -idle specification, clearmake uses a host only if it is at least 50% idle.

If CCASE_HOST_TYPE is set, but clearmake cannot find or read the build hosts file, it does not perform the build. (clearmake assumes that if CCASE_HOST_TYPE is set, you want to perform a parallel build. Because the parallel build might use a host with a different architecture than the local host, performing the build on the local host might yield incorrect results. Therefore, by default, clearmake does not build on the local host if CCASE_HOST_TYPE is set.)

clearmake does not use a host during a parallel build if your current view cannot be used on that host. (For example, the host might not be able to access the view's storage directory.)

You set the CCASE_HOST_TYPE variable conditionally in your makefile, using target-dependent variable bindings. If you set the variable on the clearmake command line, in your process environment, or unconditionally in your makefile, it applies to all targets.

For example, to ensure that the target x is built on host neon or saturn:

x := CCASE_BLD_HOSTS = neon saturn

You can also use patterns in target names. For example, to build all .o files on host pluto:

%.o := CCASE_BLD_HOSTS = pluto

clearmake applies CCASE_BLD_HOSTS bindings to dependencies of the specified targets. To apply CCASE_BLD_HOSTS to the specified targets but not their dependencies, add the following line to the built-ins file for your compatibility mode:

To determine the name of any .bldhost file clearmake reads during the build process, use the clearmake -v command.