Koala STC

The tool koala-stc translates a Koala composition to a composite source tree. This process is called Source Tree Composition.

The basic idea is that for koala-stc Koala modules do not correspond to C source files but to source distributions (e.g., gzipped tar files). A composition consists of a source tree containing all unpacked source distributions, together with an integrated configuration and build process. This composite source tree can be handled as a unit, such that building and configuring can be done for the source tree as a whole, rather than for each subcomponent individually.

More on this topic can be found here:

• de Jonge, M. (2004). Multi-level Component Composition. Bosch, Jan, Ed. 2nd Groningen Workshop on Software Variability Modeling (SVM'04).
• de Jonge, M. (2004). Decoupling Source Trees into Build-Level Components. Bosch, J. and C. Krueger, Ed. Proceedings: Eighth International Conference on Software Reuse. 215--231. Springer-Verlag.
• de Jonge, M. (2002). Source Tree Composition. Gacek, Cristina, Ed. Proceedings: Seventh International Conference on Software Reuse. 17--32. Springer-Verlag.

The koala-stc tool takes as input a Koala composition and produces as output a source tree in which all modules are unpacked, and an GNU build environment that includes a set of Automake Makefiles and an Autoconf configuration script. The generated files will be stored in the directory specified with the '-d' command line switch (defaults to current working directory).

koala-stc -I <directory with Koala components> \
           -i <top-level component> \
           -d <output-dir>

The resulting source tree can now be compiled in the following steps:

   cd <output-dir>
   autoreconf -if
   configure --prefix <installation prefix> -C
   make install

The tool koala-stc makes an assumption about variability interfaces. An interface definition is assumed to be a variability interfaces iff the interface definition does not contain function prototypes. Thus, an interface definition is a variability interface if it consists solely of parameters, constants, or defined functions.

Parameters of variability interfaces that are not bound (and become constants) during the normalization process, become paramters of the composite bundle. This means that they propagate to top-level Autoconf configuration switches. These parameters can then be bound at configuration time. E.g., a parameter debug can be bound s follows:

   configure --with-debug=<some value>

The directory demos/stc in the source distribution of KoalaCompiler (see HowToObtainKoalaCompiler) contains examples of koala-stc

-- MerijnDeJonge - 22 Dec 2004