Re: Conditional compilation of debug traces without cpp

["Martin Krischik" <krischik@users.sourceforge.net>]

guillaume.portail@grospied.enanglais.com wrote:
> Jean-Pierre Rosen wrote:
>
> > Switching packages is then not more difficult than changing a #define...
>
> Nice, thank you ! And thank you for your Debug package, I already know
> about it.
>
> But don't you think that the elaboration of the calls will still exist ?
> Executing the statement :
>
> 	Null_Proc ("I was here" & Function_Call(A+12));
>
> will always produce a call to Function_Call, even if Null_Proc has a
> null body, I guess.
> I have zillion of 'complicated' traces like this :
>
> 	Traces.Put_Info ("Mouse at home, ears=" & (+Mice.ears)
>                                        & "tong=" & (+Mice.tong)
>                                        ...
>                                        & "legs=" & (+Mice.legs));
>
> where "+" is a rename of some kind of 'Image, may be a sophisticated
> one. In general returning fixed-length strings, but not always. So I
> suspect that theses traces call every "+" involved in the elaboration of
> the call, maybe doing heap allocation, even when Trace.Put_info is null.

Indeed. For simple cases "-O3" and "pragma Inline" will help. For GNAT
you can take it furher with pragma "Pure_Function" but you are right:
eventually you reach the point where functions will be called even when
the result is not needed.

You could use "GNAT PREPROCESS" - which gives you the same solution as
C/C++: a text preprocessor. With all the advantages and disadvantages.
Well not quite: "GNAT PREPROCESS" writes the preprocessed file to the
drive - which has it's own set advantages and disadvantages.

Martin