Rewritten December 2023
The identifier DEBUG can be either a read-only system variable returning the debug level as set by SET.LIT, or a standard variable, depending on the following:
| • | If the /X:2 compiler switch is specified, then DEBUG is treated as the system variable, provided it has not been previously mapped as a regular user variable. |
| • | If the /DEBUG compiler switch is specified, then DEBUG is always treated as a read-only system variable whose value is 1. This is intended to allow an easy way of compiling a program in "debug mode". |
| • | If neither /X:2 nor /DEBUG switches specified, then DEBUG is treated as an ordinary variable. If not mapped and /M not specified, it will be auto-mapped like any other unmapped variable. |
Example
if DEBUG then
? "--DEBUG level set to ";DEBUG
else
? "--DEBUG not set"
endif
If the above program was named SHOWDEBUG and compiled using the /X:2 switch, then...
.SET DEBUG
.RUN SHOWDEBUG
-DEBUG level set to 1
.SET DEBUG 9
.RUN SHOWDEBUG
--DEBUG level set to 9
.SET NODEBUG
.RUN SHOWDEBUG
--DEBUG not set
If compiled without the /X:2 switch, DEBUG would be treated as an unmapped variable, either initialized to 0, or if /M specified, generating an unmapped variable error.
If compiled with both the /DEBUG and /X:2 switches, then regardless of any prior SET DEBUG statement, the result would be...
.RUN SHOWDEBUG
--DEBUG level set to 1
Comments
Regardless of the compiler switches, DEBUG acts like a variable and not a symbol, and thus cannot be tested by the ++IFxxx Conditional Compilation directives.
See Also
| • | SET.LIT |
