*Description*

The Koala compiler toolkit forms a generic framework for component composition. The framework works as follows:

	1 Components and compositions are expressed in the Koala component definition language
	1 The tool =koala-compiler= is used to synthesize an abstract composition. The combination of =koala-pack=, =implode-asfix=, =koala-wire=, and =koala-compiler= is called the _first-phase_ composition.
	1 Composition type-specific tools then perform a specific composition of components. The combination of tools for a particular composition type is called the _second-phase_ composition.

*First phase composition*

Given the component =koala-bundle= as showed in PackKoala, the first phase composition can be performed with the folllowing tool chain:
<verbatim>
	pack-koala -I ./koala-pb -i koala-tools-bundle \
	| implode-asfix \
	| koala-wire \
	| koala-compiler
</verbatim>

This produces an AbstractCompositionDefinition, describing the ingredients of the composition, its structure, as well as relations between modules and components in the composition.

*Second phase composition*

The second phase composition depends on the particular _composition-type_. Below we explain how [[http://www.cs.uu.nl/groups/ST/Merijn/PaperSourceTreeComposition][Source Tree Composition]] can be performed as second phase composition.

[[http://www.cs.uu.nl/groups/ST/Merijn/PaperSourceTreeComposition][Source Tree Composition]] consists of 
	1 Determining the build order of the components in the composition. This is performed by the tools =koala-tred= and =koala-build-order=. The first tool replaces transitive references (m1->C1->C2->m2) by direct references (m1->m2). The second tool reorders modules such that if a module is referenced, it occurs before the referencing module.
	1 Obtaining and integrating source trees. This is achieved with the tool =koala-tree-composer=. This tool produces a shell script that, when executed creates a directory hierarchy in which it unpacks the source trees of all components.
	1 Synthesizing a build and configuration process. This is achieved with the tool =koala-build-composer=. This tool creates in the constructed directory hierarchy a top-level Autoconf =configure= scripts as well as Automake =Makefiles=.

The second phase composition therefore consists of the following tool invocations:
<verbatim>
	koala-tred \
	| koala-buildorder \
	| koala-tree-composer -o <prefix> > composer.sh
	sh ./composer.sh

	koala-tred \
	| koala-buildorder \
	| koala-build-composer -o <prefix>
</verbatim>

The location where the source tree is produced is denoted with =&lt;prefix&gt;=.

You can now compile the generated composition:
<verbatim>
	cd <prefix>
	sh ./bootstrap.sh
	./configure
	make install
</verbatim>


We started developing some other second phase composition tools, including a petri-net  composer and a graph composer.






-- Main.MerijnDeJonge - 17 Feb 2004