— Component: source-file

A source file is any file that the system does not know how to generate from other components of the system.

Note that this is not necessarily the same thing as “a file containing data that is typically fed to a compiler”. If a file is generated by some pre-processor stage (e.g. a .h file from .h.in by autoconf) then it is not, by this definition, a source file. Conversely, we might have a graphic file that cannot be automatically regenerated, or a proprietary shared library that we received as a binary: these do count as source files for our purposes.

Subclasses of source-file exist for various languages. FIXME: describe these.

— Component: module

A module is a collection of sub-components.

A module component has the following extra initargs:

• :components the components contained in this module
• :default-component-class All child components which don't specify their class explicitly are inferred to be of this type.
• :if-component-dep-fails This attribute takes one of the values :fail, :try-next, :ignore, its default value is :fail. The other values can be used for implementing conditional compilation based on implementation *features*, for the case where it is not necessary for all files in a module to be compiled.
• :serial When this attribute is set, each subcomponent of this component is assumed to depend on all subcomponents before it in the list given to :components, i.e. all of them are loaded before a compile or load operation is performed on it.

The default operation knows how to traverse a module, so most operations will not need to provide methods specialised on modules.

module may be subclassed to represent components such as foreign-language linked libraries or archive files.

— Component: system

system is a subclass of module.

A system is a module with a few extra attributes for documentation purposes; these are given elsewhere. See The defsystem grammar.

Users can create new classes for their systems: the default defsystem macro takes a :classs keyword argument.