22. Creating a build_visit Module¶

To create the skeleton for a build_visit module, run construct_build_visit_module.sh <module>, where <module> is the name of the library you wish to build. The script is located in src/tools/dev/scripts/bv_support. For purposes of the rest of this section, <module> will be named foo.

Running construct_build_visit_module.sh foo will create the file: bv_foo.sh containing most of the code needed, and only a few functions will require modification.

There are three functions in the file that absolutely need to be fleshed out further: bv_foo_info, bv_foo_host_profile, and build_foo. Other build_visit modules may be helpful as examples for filling these out. If the package being built has a decent CMake build system, please use that in the build_foo function.

Here is a list of all the functions that will be defined (listed in order of appearance in the file):

bv_foo_initialize: Initialize any variables controlled by command line options.
bv_foo_enable: Enables the module (sets DO_FOO to yes).
bv_foo_disable: Disables the module (sets DO_FOO to no).
bv_foo_depends_on: What other modules does foo depend on. For example, the osmesa module returns llvm.
bv_foo_info: Name of the foo tarball, the version, etc.
bv_foo_print: Prints info about the foo module.
bv_foo_print_usage: Prints how to enable the module and any other relevant command line args.
bv_foo_host_profile: Adds the necessary information about the foo module to config-site host profile cmake file. Most often this is just the insall location, but could also be version information.
bv_foo_initialize_vars: Set vars possibly needed by other modules, such as install location for the module (can use EXPORT). This is an optional function and can be removed if not needed.
bv_foo_ensure: Ensure the module has been downloaded and extracted properly.
build_foo: Where all the steps for building and installing the module reside.
bv_foo_is_enabled: Returns true if the module is enabled, and false otherwise
bv_foo_is_installed: Returns true if the module is installed, and false otherwise
bv_foo_build: Checks if foo is already installed, and calls build_foo if not.

Most of the above referenced functions will suit fine as originally written by the construction script.

If your module has dependencies on other build_visit modules, then also modify bv_foo_depends_on.

If you want to allow use of a system version of your module, then bv_foo_initialize needs work to ensure extra command line arguments are added. See bv_qt.sh as an example of allowing system or also an alternate (already installed but not system) qt. bv_qt_system_qt and bv_alt_qt_dir were added and other functions were modified to support this for qt.

Once bv_foo.sh has been updated appropriately, add the module name to bv_support/modules.xml under the appropriate categories. Then run the build_visit script to ensure that your module builds and installs correctly, and that the host profile entry is correct.

Order of execution of the functions:

bv_foo_initialize
bv_foo_info
bv_foo_[enable|disable]
bv_foo_is_enabled
bv_foo_initialize_vars (if defined)
bv_foo_ensure
bv_foo_is_enabled
bv_foo_is_installed
bv_foo_depends_on
bv_foo_build
bv_foo_host_profile