A.17 STAR_DEFAULTS

STAR_DEFAULTS([options=''])

Sets up the defaults for Starlink configure.ac files. The optional OPTIONS argument holds a space-separated list of option keywords, of which the only ones defined at present are per-package-dirs and docs-only.

As part of its initialisation, this macro does the following:

• Makes sure that the variable STARLINK is defined, so that you can use it elsewhere in your configure.ac file. The value of this variable depends on the STARCONF_DEFAULT_STARLINK variable which is defined by the ./starconf.status script (see Section 2.2), and can be overridden by a setting of STARLINK in the environment, though you are discouraged from doing that.
• Sets appropriate vales for variables AM_FCFLAGS and AM_LDFLAGS (you shouldn't have to care, as the point of these prefixed variables is that they should be orthogonal to the unprefixed variables with the similar names, but see Section 6.4 for a gotcha).
• Defines and substitutes variables PACKAGE_VERSION_MAJOR, ..._MINOR, ..._RELEASE and ..._INTEGER. These are respectively the major, minor and release numbers extracted from PACKAGE_VERSION, and an integer representation of these consisting of major * 1000000 + minor * 1000 + release.

This macro also sets the prefix shell variable to its default value. Standard autoconf ./configure scripts also do this, but at a slightly later stage, which prevents the variable being used safely within configure.ac scripts. This is useful if you have to configure a thirdparty package in a subdirectory, by calling its ./configure script with a suitable --prefix option.

The option per-package-dirs, has three consequences:

1. applications, help and etc files are installed in a package-specific directory (however the fac_*_err files are regarded as being in a separate category, and still install in /star/help, without any package-specific prefix);
2. the otherwise-forbidden variable bin_DATA is permitted: any files assigned to this variable are installed in the (package-specific) binary directory as data, as opposed to executables;
3. a file version.dat is created (at make rather than install time). This holds the bare PACKAGE_VERSION number, and is installed in the binary directory.

The docs-dir option declares that this component contains only documentation (or at least, no code). This triggers mild changes in the behaviour of the STAR_DEFAULTS macro which should make configuration somewhat faster in this case. Certain other macros, such as STAR_MESSGEN, are disabled.