Version Control

TRANSX is maintained using the UPD code (Ref. 27), which is similar in concept to the UPDATE code used on Cray and CDC systems. It keeps a history of changes to a computer code that is very useful as part of a Quality Assurance (QA) program. However, UPD is much simpler than UPDATE, thereby facilitating transport from system to system. This transportability is very important, because it ensures that one set of ``updates'' will produce the same code for compilation on all the target systems. With other systems used in the past, modifications sometimes behaved differently on different systems.

UPD reads two files. The file named SRC contains the base version of the source code for the program. This file can be broken up into separately named sections with ``*DECK name'' cards. However, TRANSX uses only the single deck named ``TRANSX.'' For simplicity, there is no counterpart to the binary ``program library'' used in the UPDATE system. The second file is called UPN, and it contains the commands to modify the base source file into a compiler input file for the current version.

The following example illustrates the features of the UPN file needed for maintaining the TRANSX code:

*CPL
*LST
*IDENT UP1
*/ 6 JAN 92 -- INCREASE SIZE OF MAIN CONTAINER ARRAY
*D TRANSX.182
      DIMENSION A(500000)
*D TRANSX.222
      NAMAX=500000
*IDENT VERS
*/ VERSION UPDATE FOR TRANSX
*D TRANSX.12
C     VERS. 2.1 (6 JAN 92)
*D TRANSX.216
      DATA VERS/'  VERS. 2.1 (6 JAN 92)'/
*IDENT UNICOS
*/ ----------------------------------------------------
*/ MACHINE-DEPENDENT CHANGES TO TRANSX
*/ FOR CRAY-XMP MACHINES USING UNICOS AT LOS ALAMOS
*/ ----------------------------------------------------
*/ ELAPSED TIME
*D TRANSX.3806
      CALL SECOND(TIME)
*/ DATE
*D TRANSX.3816
      CALL DATE(HDATE)
*/ WALL CLOCK TIME
*D TRANSX.3826
      CALL CLOCK(HTIME)

The first line of this example gives the command CPL, which causes a compiler input file named CPL to be written containing the updated program. The command LST causes a listing file named LST to be written. These listing files are a little easier to read than normal CPL files.

The first set of changes begins with the card *IDENT UP1. The modified lines on the CPL or LST files will contain labels like UP1.2, UP1.3, etc. This particular ``ident'' changes two lines in order to increase the size of the main container array. The symbol ``*/'' introduces a comment line. It is very important for QA purposes to include comments in each ident that describe the purpose of the change. It is also very important that each change be dated as shown.

The next ident updates the version label on the code listing and the version string that is written to every TRANSX listing file. The numbering convention used for TRANSX is suggested by this example. Including an ident called UP1 increments the TRANSX version to 2.1; UP2 would give 2.2; and so on. Note that the date from the last ident is transferred to ident VERS. This scheme will be used for all ``official'' changes to TRANSX. Users are free to make private changes using their own special ident names.

The third ident implements some machine-dependent changes. These changes will be discussed below.

The general format for the delete command is

*D line1,line2

If ``,line2'' is omitted, line2 is taken to be the same as line1. The actual values for the line references can refer to lines in the base code (e.g., TRANSX.234) or to changed lines (e.g., UP1.2). In general, any line label that appears on the current CPL or LST file can be used. The delete command causes the range of lines named to be removed, and any text following the command is inserted at that point in the file. The insert command has the form

*I line1

Any text following the command is inserted after the named line. There is also a ``before'' command:

*B line1

that causes the following lines to be inserted before the named line. Other features of the UPD code and more details on its use will be found in the UPD report.

TRANSX HyperText Manual
TRANSX HyperText Help Package
T-2 Nuclear Information Service