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From: "Stephen Kennedy" <Stephen.Kennedy@havok.com>
To: nobody@gcc.gnu.org
Cc: gcc-prs@gcc.gnu.org,
Subject: RE: c/9762: Address of 'char' is incorrect.
Date: Thu, 20 Feb 2003 18:36:00 -0000	[thread overview]
Message-ID: <20030220183600.3822.qmail@sources.redhat.com> (raw)

The following reply was made to PR c/9762; it has been noted by GNATS.

From: "Stephen Kennedy" <Stephen.Kennedy@havok.com>
To: "'Neil Booth'" <neil@daikokuya.co.uk>
Cc: <gcc-gnats@gcc.gnu.org>,
	<debian-gcc@lists.debian.org>
Subject: RE: c/9762: Address of 'char' is incorrect.
Date: Thu, 20 Feb 2003 18:32:19 -0000

 OK, the C standard does not say that this should work, so you
 can consider this bug closed.
 
 However, given knowledge of the calling convention of a
 particular machine, you can do neat things such as dynamic
 function binding. See www.drizzle.com/~scottb/gdc/fubi-paper.htm
 for instance.
 
 I've since changed to using assembly, but why does gcc
 return the address of a temp when 'a' is a char and not
 when 'a' is an int?
 
 Surprised, not unhappy,
 Stephen.
 
 ---
 Stephen Kennedy <Stephen.Kennedy@havok.com>
 t: +353 1 6693679   f: +353 1 6767094
 Game Developer Frontline Award Winner
 http://www.havok.com/news/release.html
 
 > > 	In the example below, '&a' is the address of a local 
 > copy of 'a' not of 'a'.
 > > 	if the type of 'a' is changed to int, it works as expected.
 > 
 > Works as who expected?  Where is the bug?  Please quote which part of
 > the C standard is violated.  You got an address, why are you unhappy?
 > 
 > Neil.
 > 
 > > #define TA char
 > > #define TB int
 > > #define TC int
 > > 
 > > void foobar(TA a, TB b, TC c);
 > > 
 > > int main()
 > > {
 > > 	foobar(1,2,3);
 > > 	return 0;
 > > }
 > > 
 > > void foobar(TA a, TB b, TC c)
 > > {
 > > 	printf("a == %i  claims %x\n", a, &a);
 > > 	printf("a == %i  really %x\n", (&b)[-1], (&b)-1);
 > > 	printf("b == %i  %x\n", b, &b);
 > > 	printf("c == %i  %x\n", c, &c);
 > > }
 > 


             reply	other threads:[~2003-02-20 18:36 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-02-20 18:36 Stephen Kennedy [this message]
  -- strict thread matches above, loose matches on Subject: below --
2003-02-20 20:33 neil
2003-02-20 19:06 Daniel Jacobowitz
2003-02-20 14:36 Andreas Schwab
2003-02-20  8:06 ebotcazou
2003-02-19 21:26 Neil Booth
2003-02-19 19:56 stephen.kennedy

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