We have seen before how preprocessor statements in source code can be a source of problems for program tracing. The problem is even more serious for wholesale parsing of source code, because the preprocessor and Delphi are effectively two languages mixed together. When a program is compiled, the preprocessor code is evaluated first, producing a file that only has Delphi left. This is the Delphi source code that effectively is compiled.
Evaluating the preprocessor code is thus a sort of partial compilation of the program, from preprocessor/Delphi down to Delphi.
Unfortunately, BDS has no tool for preprocessing, but there is a preprocessor
called DIPP
written by Ralf Junker. The preprocess.py tool uses DIPP internally.
You can preprocess a single file or a codebase at large, but you have to know two things:
H-, R+ and are
listed in the DelphiCompilerFlags file.DEBUG can
either be set or not set. These are also listed in the DelphiCompilerFlags
file.You can preprocess without setting either one, but then your program may not evaluate correctly.
You then run the tool:
$ preprocess.py -d "H-;R+" -c "DEBUG;WIN" Root.dpr
>> Preprocessing includes in Root.dpr ...
[/home/frank/code/samples/preproc] + wine /home/frank/code/dipp/dipp-1.6.1.exe \
Root.dpr /tmp/.Root.dpr -o -PD2006 -li
The Delphi Inspiration Pascal Preprocessor - Version 1.6.1
Copyright (c) 2003-2010 Ralf Junker, The Delphi Inpiration
http://www.yunqa.de/delphi/
In: Z:\home\frank\code\samples\preproc\Root.dpr
Out: Z:\tmp\.Root.dpr
Processed 16 lines in 1 ms.
* DONE ...
>> Preprocessing conditionals in Root.dpr ...
[/home/frank/code/samples/preproc] + wine /home/frank/code/dipp/dipp-1.6.1.exe \
Root.dpr /tmp/.Root.dpr -o -PD2006 -c -h '-DDEBUG;WIN'
The Delphi Inspiration Pascal Preprocessor - Version 1.6.1
Copyright (c) 2003-2010 Ralf Junker, The Delphi Inpiration
http://www.yunqa.de/delphi/
In: Z:\home\frank\code\samples\preproc\Root.dpr
Out: Z:\tmp\.Root.dpr
Processed 16 lines in 0 ms.
* DONE ...
Preprocessing happens in two steps: