COBOL Manual for TNS and TNS/R Programs

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Issues Related to Binding and Linking

HP COBOL Manual for TNS and TNS/R Programs—522555-006

24-2

Code and Data Blocks

How the Compiler Produces Code and Data Blocks

To understand how the compiler produces code and data blocks from HP COBOL

source code, you must know about separately compiled programs and compilation

units.

A separately compiled program is an HP COBOL source program that is not nested

within any other program. It can have other HP COBOL source programs nested within

it.

A compilation unit is a collection of source statements presented to a compiler in one

compilation. It contains one or more separately compiled programs.

For each compilation unit, the compiler produces a single object file. For each

separately compiled program in the compilation unit, the object file contains one

relocatable code block for the outermost source program, one relocatable code block

for each program nested inside the outermost source program, and one or more data

blocks. Each nest of programs produces an indivisible nest of code blocks. In the

object file, the code and data blocks exist solely as named code blocks and data

blocks; they do not have a collective identity.

Figure 24-1. Code and Data Blocks

Compiler

Separately compiled program A

Separately compiled program B

Nested program C

Nested program D

Code

Block

Code

Block

Code

Block

Code

Block

Data

Block

Data

Block

Data

Block

Data

Block

Data

Block

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