Most non-trivial C programs make extensive use of data structures. For the user attempting to understand unfamiliar code, comprehending the data structures at the heart of a program may be at least as important as understanding the details of functional dependencies.
HyperCode provides links from programmer-defined data type names in
variable declarations to the corresponding data structure definitions.
A user browsing HyperCode with Mosaic, for instance, can click
on a type name to view the definition of the structure that the type
name represents (Figure 5). Of course, if a data
structure contains elements which are of programmer-defined types,
they are linked to their respective definitions. HyperCode thus enables a
user to explore data structure dependencies as easily as function
dependencies.
Further parallelling the treatment of functions, HyperCode provides
links from type definitions to lists of their use sites (Figure
6). Each element of a type backtrace list is, in
turn, linked to the site in the code which it describes; thus, from a
type definition, a user can discover each variable which is declared
to be of that type.
As with function links, the data type links provided by HyperCode
explicitly represent an important aspect of program structure;
specifically, data type links encode the entire set of data structure
relationships used by a program. Again as with function links, data
type links are extremely useful to a user considering modifying
particular structures: data type links make it easy to evaluate the
effects of a proposed modification to a data structure on every
dependent data structure and variable.
