Constants defined by the compiler Foundation

By default, the Xbase++ compiler predefines some constants to identify the compiler and to identify the operating system. This allows program code specific for a compiler or an operating system to be excluded from compilation, using the directives #ifdef, #ifndef, #else and #endif. The #define constants are:

For example, if the same PRG file is to be compiled by Xbase++ and Clipper, there may be situations where both compilers behave differently. Such conflicts can be resolved as follows:

#ifdef __XPP__ 
    <Xbase++ Code> 
#else 
    <Clipper Code> 
#endif 

#ifdef XPPVER 
#if XPPVER > 01810000 
    <requires Xbase++ higher than version 1.8 to compile> 
#endif 
#endif 

In this way, program code for different compilers can be maintained in the very same PRG file.

Additional constants defined by the compiler are available for debugging and/or versioning purposes. They can be used in the following way:

? __FILE__, __LINE__, __DATE__, __TIME__ 

The compiler replaces these constants with the corresponding information, i.e. the values for these constants change while the compiler processes source code files.

__FILE__

A character string containing the name of the source code file.

__FILEPATH__

A character string containing the name and the complete path of the source code file.

__LINE__

A numeric value indicating the source line number where this constant appears.

__DATE__

A character string containing the compilation date in the format "YYYYMMDD", with YYYY being the year, DD is the day and MM is the month. This format can be converted to a variable of type Date by Stod().

__TIME__

A character string containing the compilation time in the format HH:MM:SS.