Configuration Options in vtf/setup

• CACR=yes (default). This requests our CACR default compiler and environment variable settings for known ASC platforms. This setting should be changed to CACR=no for all other platforms. See below for discussion of influential environment variables.
• OPT=no (default). This setting can be changed to OPT=yes to turn on compiler optimizations. By default, an optimized build is done when CACR=yes, otherwise a debug build is performed.
• MPI=no (default). By default, a serial build is performed. Setting MPI=yes will enable MPI support.
• BIT64=no (default). This setting can be changed to BIT64=yes to request a 64-bit build on platforms that support both 32-bit and 64-bit executables. The correct functioning of this option has not been verfied yet. This feature is fully experimental and should not be used for production.
• CACHE=yes (default). By default, configuration options and results of autoconf tests are cached to reduce configuration time and preserve a record of the previous configure options. Setting CACHE=no will disable configure option caching.
• OPTIONS. Used to pass additional configuration options directly to the configure script. Type ./configure --help to see all the available options and a brief description of each option.

Supported shell environment variables

Shell variables for configure should never be specified in the shell environment before running configure but provided as arguments of the configure call as vtf/setup demonstrates it. It is correct to say for instance ./configure CC=bizarre-cc, but incorrect to say CC=bizarre-cc ./configure, which, unfortunately, is what most users do. See autoconf manual, AC_ARG_VAR section. Variables specified directly in the configure call are automatically cached and will be used with the stored values during config.status --recheck without specifying them permanently in the shell environment. Below is a list of influential environment variables. If necessary, these may be set explicitly in the setup script, or placed on the configure command line by adding the settings to the OPTIONS variable.

CACR=yes (default)

Using the CACR default settings on a known ASC platform, it should not be necessary to set any additional environment variables. Simply configure your machine-dependent environment as described in VTF Installation and Configuration. Nevertheless, you may wish to selectively override some of the CACR default settings. You can use the variables in the table below for this purpose. This information can also be viewed by typing ./configure --help.

In addition to these variables, there are a few variables that are used to indicate the location of certain external software packages. Again, these variables are given proper default settings on all known ASC platforms when CACR=yes is used.

CACR=no

When configuring on a non-ASC platform, you may use the environment variables shown in the first and second table above to override the default compilers that are selected. For a build with MPI support enabled, you have two possible options. If your machine has mpich installed, you can put the mpich bin directory in your PATH and use the standard mpich compiler driver commands: mpiCC, mpicc and mpif77. If you do not have such compiler driver commands available, you can use your own compiler and use environment variable settings to supply the necessary flags:

-- RalfDeiterding, JulianCummings - 03 Mar 2005