Re: [DotGNU]Hello from pnetC

[Erik Rozendaal]

Rhys Weatherley wrote:

> Gopal already found one oddity last night when he became
> the first test victim: evaluation order is the reverse of
> regular C compilers.
>
>    int i=10;
>    printf("%d %d %d",i++,i++,i++);
>
>    gcc : 12 11 10
>    cscc: 10 11 12
>
> This is due to the way the CLR works.  It always evaluates
> from left to right, instead of the usual C right to left.
> I don't think that there is anything that we can do about
> this, unfortunately.
Actually, this is undefined behavior in C. Modifying a variable multiple 
time between sequence points (usually between statements, but there are 
other sequence points) is not allowed. Also, in C the evaluation order 
of function call arguments is not defined either. So both gcc and cscc 
are "correct". Although a correct (but evil) compiler could also format 
your harddrive...

See section 3 of the C FAQ at http://www.eskimo.com/~scs/C-faq/top.html 
for more about sequence points. It'll quickly make you want to program 
C# or Java again :)

Erik