.IFDEF-.ELSE-.ENDC
Perform conditional processing
WTSupported in traditional Synergy on Windows
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WNSupported in Synergy .NET on Windows
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USupported on UNIX
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VSupported on OpenVMS
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.IFDEF data_element [. . . source_1 . . .] [.ELSE . . . [source_2 . . .]] .ENDC
Arguments
data_ element
One of the following:
- A defined macro
- A data declaration in the current routine
- A data declaration in a class
- A data declaration in a structure, defined at any level and visible at that moment in processing
- An enumeration
source_1
(optional) One or more lines of source code.
source_2
(optional) One or more lines of source code.
Discussion
The .IFDEF compilation control directive indicates that the statements that follow are to be compiled if the specified data element has already been defined.
The source_1 lines of code are compiled only if the specified variable or identifier is defined prior to the .IFDEF directive. If the .ELSE directive is present, the source_2 lines of code are compiled only if the specified variable or identifier is not defined prior to the .IFDEF directive.
You can use one or more of the .ELSE, .IFT, .IFF, and .IFTF directives within an .IFDEF conditional block. These conditional compilation control directives can be nested.
The .ENDC directive must always close an .IFDEF conditional block. If .ENDC is not present, a warning is generated.
Examples
The following example shows a simple conditional compilation control operation.
.define TTCHN ,1 .define DEBUG proc open(TTCHN, o, "tt:") . . . .ifdef DEBUG writes(TTCHN, "Entering mod1") ;This code will be compiled. .endc
The following example shows nesting of the .IFDEF conditional compilation control directive.
.define SHOWTABLES .define SHOWTBLB .define TTCHN ,1 proc open(TTCHN, o, "tt:") . . . .ifdef SHOWTABLES .ifdef SHOWTBLA writes(TTCHN, "Table A") ;This code won't be compiled. .endc .ifdef SHOWTBLB writes(TTCHN, "Table B") ;This code will be compiled. .endc .endc