World Wide Guide to FS Scenery Design | Utilities | Decompilers and Debuggers

BGLTST - A powerful debugger

BGLTST is a very useful little program that will scan a scenery file and tell you whether there are programming errors. It's not the very first of its kind, but it is the first widely-available debugger designed as a standalone program.

It will prove valuable for any scenery creator who works directly with source code (or is prepared to work with it for the sake of fixing problems!)

It focuses on the most common kinds of error -- illegal jumps or missing Return statements. [A detailed guide to source code is being prepared for these World Wide Guide pages.]

Like most such tools, BGLTST is a command-line utility. To use it, you simply copy this tool and the scenery file into the same directory, and then type a command that looks like this:

BGLTST Chicago.bgl

That would analyze and report any problems found in the Chicago scenery file, which according to this utility, includes two errors (in the FS5.1 version) where the programmer called or exited a subroutine without using a Return statement. (Such errors will not necessarily always cause problems, but they are to blame for most of the reported "Database errors".)

There are a number of special options you can select by adding parameters to the command line.

BGLTST is most useful when used with SCASM, because the latest versions of SCASM (1.7 and later) can produce a special "map" file that allows BGLTST to provide more descriptive information about the precise location of an error. When you compile code using SCASM, it can generate a map file which BGLTST can use for such reporting purposes. Nevertheless, even without a map file, BGLTST will report which Area an error occurs in, so at least it directs you to the approximate location of an error.

It will also tell you the "maximum subroutine level", which is the greatest number of "nesting" levels found anywhere in the file. This is one measure of the complexity found in the scenery code.

Documentation: Good. Assumes that you have some familiarity with scenery source code, which is probably a fair assumption if you're interested in finding source code errors.
Author: Manfred Moldenhauer [e-mail: 100117.1465@compuserve.com] of Hamburg, Germany, author of the widely-used SCASM compiler.
Distribution: Freeware
Version: 1.0
Size of compressed distribution file (BGLTST.ZIP): 30 KB
Date on main program file (BGLTST.EXE): 12 December 1996