OCCAM Preprocessor

Program occpp is an OCCAM preprocessor, developed by Andres Kruse. A more comprehensive description of the program than given here can be found in [7]. The purpose of occpp is to extend the number of available compiler metacommands, as follows:

• #DEFINE variable
  a statement to define a variable.
• #UNDEF variable
  undefine a variable.
• #IFDEF variable, #ENDIF
  if the variable is defined the code that is enclosed between these two statements will be processed further.
• #IFNDEF variable, #ENDIF
  if the variable is defined the code will NOT be processed further.
• #ELSE
  extension to #IFDEF and #IFNDEF

With the -D and -U option this preprocessor can be used as a tool to have conditionally compiled code.

The syntax is as follows:

occpp [-v] [[-Dvariable1] [-Dvariable2]...] [[-Uvariable1] [-Uvariable2]...] file[s]

with:

• -h
  give usage information (no processing)
• -v
  print information while processing
• -V
  print debug information
• -F
  force occpp to overwrite existing .occ and .inc files (normally it will only overwrite .occ and .inc files if they differ from the new version (good for make!))
• -Dvariable define the variable to be TRUE this cannot be overwritten by an #UNDEF in the file !
• -Uvariable define the variable to be FALSE this cannot be overwritten by an #DEFINE in the file !
• -o file name of the output file then only one input file is allowed
• file[s] names of the occam source files; the extension has to be .opp or .ipp or .ppp.

occp will automatically generate files with the extension ``.occ'', ``.inc'' and ``.pgm''