Re: Pascal Calling Convention

[Keith Thompson <kst-u@mib.org>]

Dennis Lee Bieber <wlfraed@ix.netcom.com> writes:
> On Thu, 24 Mar 2011 01:43:57 +0100, Yannick Duchêne (Hibou57)
> <yannick_duchene@yahoo.fr> declaimed the following in comp.lang.ada:
>
>> [ebp+0] := ... [ebp+4] := ... and so on. But I feel to remember parameter  
>> passing order for WinAPI is the reversed one than C. I will have a test  
>> tomorrow to check (I am not running Windows right now).
>
> 	Could it be (hypothesis) that it is the parameter /evaluation/ order
> which is reversed?
>
> 	That is, does
>
> 	i = 0;
> 	someC(i++, i++, i++);
>
> produce
> 		(0, 1, 2)
> or
> 		(2, 1, 0)

On my system, it produced (2, 1, 0), but this doesn't mean anything.
In C, the order of evaluation of function arguments is explicitly
unspecified.  Furthermore, in this particular case, the multiple
modifications to the same object without an intervening sequence
point mean that the behavior of the program is undefined; it
could legitimately print "a suffusion of yellow" or cause your
keyboard to explode.  (C's "undefined behavior" is very much like
Ada's "erroneous execution" -- and IMHO C chose a better term to
describe it.)

Furthermore, the order of evaluation of the argument expressions
isn't *necessarily* related to the order in which the results are
pushed onto the stack (assuming there even is a stack).

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
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