🚀 go-pugleaf

In article <8810160211.AA07329@sun.mcs.clarkson.edu> gary@SUN.MCS.CLARKSON.EDU (Gary Levin) writes:
>certain prototype definitions appear not to be accepted.
>
>why does it complain about yyy, but not xxx?  seems that there is a
>curious bug in the prototyping code.
>
>------
>char * yyy();
>extern char * yyy(char *, char);
>
>char * xxx();
>extern char * xxx(int,int);
>-----
>
>Until it is fixed, I can't make use of the prototype checking, because
>the standard includes don't have the prototype info.  (yyy is the same
>as index).

It better not be fixed! It is right!

The reason is this:  When the compiler sees

	char *yyy()

It assumes that all args get passed as 32 bit quantities.  Once it
actually knows that the size of a char is 8 bits, it is free to
(consistently) pass that as an 8 bit or 16 bit quantity if the
architecture allows.

	char *xxx(int, int)

on the other hand, doesn't in any way affect arg passing on a 32 bit
int machine.  Therefore,

	char *yyy(char *, char)

need not have the same stack layout as

	char *yyy()

Jon

Thanks to those who pointed out the relation between the old and new
definitions and the old and new function heads.  The ANSI standard
could have been written more clearly.

Warning:  Borland's interpretation of the ANSI standard is off.  Their
view is that the prototyped definitions (i.e. prototype without the
body) would control the widening effect of BOTH the call and the
function head.  This is convenient, but, as you have shown, wrong.

My apologies for posting to the util group by mistake.  Thought I'd
send the thanks here, but further comments should move to gcc.bug
--

-----
Gary Levin/Dept of Math & CS/Clarkson Univ/Potsdam, NY 13676/(315) 268-2384
BitNet: gary@clutx   Internet: gary@clutx.clarkson.edu