Abstract: Apparatus and methods for the hierarchical display of routine call dependencies in a software program are implemented. A list of routines in a preselected software program is displayed in first and second regions in a window on an display device. By selecting a routine in the list in the first region, one or more routines called by the selected routine are displayed, in a tree hierarchy beneath the selected routine. Selection of a routine in the list in the second region displays, in a tree hierarchy, routines that call the selected routine.

Abstract: A apparatus and method for cross-referencing routines in software is implemented. Declarations in the software program are searched for routine declarations. For each routine declaration found, an entry in a first table in a database is generated and a routine identifier for the routine entered. In response to each identifier entered, the routines corresponding thereto are searched for calls to other routines. For each call, entry in a second table is generated in which, in a first field, the identifier of the routine being searched is written, and in a second field, an identifier for the called routine is written. The user may select for outputting the routines called by a particular routine, in which case, the entries are accessed via the first field and the contents of the second field are output. Alternatively, the user may select for outputting the routines called by a particular routine, in which case the entries are accessed via the second field and the contents of the first field are output.

Abstract: A method and apparatus for “drilling down” through a tree-based hierarchy are provided. Node descriptors corresponding to the nodes in the tree-based hierarchy are contained in entries in a data structure. Each node has a descriptor included in a first field in at least one entry in the data structure. A second field of the corresponding entry contains a node descriptor of a descendant node of the node corresponding to the descriptor in the first field. In response to user input, a descendant tree for a selected node is displayed by recursively searching in the first field of each entry in the data structure. Similarly, an ascendant tree is displayed by recursively searching in the second field of each entry in the data structure.