Using the DEBUG preprocessor symbol
You can use the syntax #IF DEFINED followed
by a predefined preprocessor symbol to mark a block of code for
specialized processing before it is compiled. The block of conditional
code is automatically parsed by a PowerBuilder preprocessor before
it is passed to the compiler. Most of the predefined preprocessor
symbols are used only for .NET targets, but the DEBUG symbol can
be used in standard PowerBuilder targets as well.
The symbol is useful if you want to add code to your application
to help you debug while you are testing the application. For example,
you might add a block like the following:
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#if defined DEBUG then<br>   MessageBox("Debugging","Ctr value is " + string(i))<br>#end if |
When you run or debug the application in the development environment,
the code is always parsed and you always see the message box. When
you run the executable file, the code is parsed only if the DEBUG
symbol is enabled on the General page in the Project painter. While
you are still testing the application, turning the DEBUG symbol
can help you find differences in behavior in the development environment
and the executable file.
Although you would not typically enable the DEBUG symbol in
a release build, if a problem is reported in a production application,
you can redeploy the release build with the DEBUG symbol enabled
to help determine the nature or location of the problem.
Adding breakpoints in a DEBUG block
When you use the DEBUG symbol, you can add breakpoints in
the DEBUG block only for lines of code that are not in an ELSE clause
that removes the DEBUG condition. If you attempt to add a breakpoint
in the ELSE clause, the debugger automatically switches the breakpoint
to the last line of the clause defining the DEBUG condition. Consider
this code:
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#if defined DEBUG then<br>   /*debugging code*/<br>#else<br>   /* other action*/<br>#end if |
In this example, if you add a breakpoint to the line /* other, the breakpoint would
action*/
automatically switch to the line /*debugging.
code*/
Code in ELSE clause is parsed
Note that any code that you place in the ELSE clause will
be parsed by the compiler when you build an executable file with
the DEBUG symbol disabled.
Pasting a DEBUG block into a script
You can use the Paste Special>Preprocessor>#If
Defined DEBUG Then pop–up menu item in the Script
view to paste a template into a script.
Limitations
Conditional compilation is not supported in DataWindow syntax,
structure or menu objects. You cannot edit the source code for an
object to include conditional compilation blocks that span function,
event, or variable definition boundaries.
You must rebuild your application after you add a DEBUG conditional
block.