Message-Id:	<1.5.4.32.19970731133711.0068ce34@dce03.ipt.br>
Mime-Version:	1.0
Date:	Thu, 31 Jul 1997 10:37:11 -0300
To:	ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire), djgpp AT delorie DOT com
From:	Cesar Scarpini Rabak <csrabak AT dce03 DOT ipt DOT br>
Subject:	Re: sizeof() in #if

At 05:12 27/07/97 GMT, Paul Derbyshire wrote:
>
>What about predefined macros? Info cpp macros predefined. There're bunch,
>including I think, __GNU_C__ and __DJGPP__ in DJGPP. Presumably others
>such as Microsoft C++ and Borland C++ have their own, like __BORLAND__.
>Then you make conditional compile statements like so:
>
>
>#if defined __GNU_C__
>  putpixel(dx,dy,17);
>#elif defined __BORLAND_C__
>  plotpixel(dx,dy,17,NULL);
>#else
>  #error I only compile with DJGPP or Borland
>#endif  

I'm affraid that what was being discussed is something different and earlier
of the stage the solution of yours would apply:

        the configure script GNU software uses attempts to detect the
existence and afterwads the properties of the C compiler in the installation
executing a 
'echo main{} > foo.c' and 'cc foo.c' then looking if a a.out file was
generated. If so it does some more complicated tests to check for some
properties of the compiler.

The question is: in the MS-DOG environment, the C compiler can be anything,
but in general will _not_ be called by 'cc'. In the years I worked with C
compilers in DOS I've seen CL for Microsoft, TCC and BCC for Borland
(command line only), WCL for Watcom and SC for Symantec (former Zortech
which was ZC if memory does not betray me...).

So I think the earlier advice of letting the user configure manually the
compiler is the best one after of all! OTH, _in the sources_ the macro
approach can be useful.

If people in this ng needs info on the macros of these compilers, I may
search for them and post them here, or alternatively, e-mail them on
individual basis.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Cesar Scarpini Rabak                      E-mail: csrabak AT ipt DOT br
DME/ASC                                   Phone: 55-11-268-3522 Ext.350
IPT - Instituto de Pesquisas Tecnologicas Fax:   55-11-268-5996
Av. Prof. Almeida Prado, 532.  Sao Paulo - SP 05508-901 BRAZIL
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