Context as a set of objects

A context as a set of objects has a logical structure. It is structured hierarchically as follows (see figure 6):

1. Objects at the lowest level are program definitions. They include the following objects:

   • control sections (CSECTs)

   • entry points (ENTRYs)

   • COMMON sections

   • dummy sections (DSECTs)

   • external dummy sections (XDSEC-Ds)

2. Objects at the next higher level are modules. They contain the program definitions. Modules can be object modules (OMs) or link and load modules (LLMs).

3. Objects at the next higher level are referred to as load units. A load unit contains all the modules that are linked and loaded with one load call.

4. The context itself consists of one or more load units. It is the highest-level object.

Figure 6: Logical structure of a context as a set of objects