From: Martin Stromberg <eplmst AT epl DOT ericsson DOT se>
Message-Id: <200211081254.NAA18624@lws256.lu.erisoft.se>
Subject: Re: Weird ceil() and other results
To: djgpp-workers AT delorie DOT com
Date: Fri, 8 Nov 2002 13:54:42 +0100 (MET)
In-Reply-To: <005501c2871e$2a5b9990$0100a8c0@p4> from "Andrew Cottrell" at Nov 08, 2002 10:57:47 PM
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> 
> If I comment out the #include <math.h> from the program below then the
> program compiles and links without any errors or warnings. The results are:-
>     date = 52.680000
>     date = 51.680000
>     decimalPart = 1072705824.000000
>     wholePart = 1077938047.000000
>     down = 1077939071.000000
> 
> If I include the #inclue <math.h> from the program below then the program
> compiles and links without any errors or warnings. The results are:-
>     date = 52.680000
>     date = 51.680000
>     decimalPart = 0.680000
>     wholePart = 51.000000
>     down = 52.000000
> 
> These results are correct....
> 
> Does anyone know why I would get wrong results, but no error messages if I
> do not include math.h? I would have expected to get error messages
> indicating a problem rather than a bad exe.

The reason it breaks when it breaks is that undeclared functions in C
defaults to returning int. So when something else than int is returned
things breaks. 

Does "-Wall" generate a warning message?


Right,

						MartinS