Object and program module structure

Object modules, load modules, and program objects share the same logical structure consisting of:

Control dictionaries, containing information to resolve symbolic cross-references between sections and to relocate address constants. When a language translator converts source modules into object modules, it generates a control dictionary entry whenever it processes an external symbol, address constant, or section. Most language translators produce two kinds of control dictionaries: an external symbol dictionary (ESD) and a relocation dictionary (RLD).
Text, containing the instructions and data of the program.
Identification (IDR) data, containing program control and user-provided information about the modules.
Associated data (ADATA) for various uses.

Each of these structural elements appears as one or more classes in the module.

A description of the external symbol and relocation dictionaries follows.