This module reads in all doxygen XML files and constructs a (in-memory) SQL database that serves as index. We will be performing more or less complex queries into a graph of objects; using SQL avoids having to hand-craft all that logic.

To work around C’s lack of namespaces, the doxy module defines a human-readable Target string that can be used to uniquely refer to a documented C construct, even if the name is defined in multiple files.

The first document to be read is index.xml. Then the rest of the documents are read only to determine hierarchy relationships.