what's wrong with the macro

[DaVinci]

#include<stdio. h>
#include<stdlib .h>
#include<string .h>

#define SECONDS_PER_YEA R (60*60*24*365)U L
int main()
{
unsigned long int u_i = SECONDS_PER_YEA R;
printf("%lu\n", u_i);

return 0;
}
cc -g -c -Wall -std=c99 -DDEBUG define.c
define.c: In function 'main':
define.c:17: error: expected ',' or ';' before 'UL'
make: *** [define.o] error 1

[pete]

Keith Thompson wrote:

>
ro******@ibd.nr c-cnrc.gc.ca (Walter Roberson) writes:

In article <45***********@ mindspring.com> ,
pete <pf*****@mindsp ring.comwrote:

>"Giorgio Silvestri" <gi************ **@libero.itwri tes:

#define SECONDS_PER_YEA R ((unsigned long)(60UL * 60UL * 24UL * 365UL))

>What is the cast for?

I believe it's superfluous.

Once the constant (without the cast) is computed by the parser, it
becomes a numeric value of indeterminate width -- through some unspecified
mechanism the parser knows the minimum width needed to represent it,
but it is not specifically that minimum width and not specifically UL
and so on. If the cast-less constant were determined
to be too large to match the other operand of the expression, then
widening is going to take place. In some contexts, if the constant
were determined to be able to fit within the *signed* version of
a larger type, it would be widened to *signed* rather than to
unsigned [remember, the system knows it as a numeric value at that point,
not specifically as an unsigned numeric value.]. The (unsigned long) cast
stops any uncertainty about exactly what type is going to be there.

I don't think so. C99 6.6p11 says:

The semantic rules for the evaluation of a constant expression are
the same as for nonconstant expressions.

The expression:

(60UL * 60UL * 24UL * 365UL)

is a constant expression, but not a constant (i.e., a literal).

A single integer literal with a UL suffix is of type unsigned long int
or unsigned long long int, depending on the value; all the constants
in the above are well within the guaranteed range of unsigned long, so
that's their type. Multiplying an unsigned long by an unsigned long
yields an unsigned long, so the entire expression is of type unsigned
long.

As it happens, the final result, 31536000, is also within the
guaranteed range of unsigned long, so there's no possibility of
overflow. But even if there were (say, if you wanted the number of
seconds in a millenium), an overflow wouldn't change the type of the
expression.

(60UL * 60 * 24 * 365) would be OK
even if (60 * 24 * 365) was greater than INT_MAX.

--
pete

[Serve Laurijssen]

"Frederick Gotham" <fg*******@SPAM .comwrote in message
news:8e******** ***********@new s.indigo.ie...

Keith Thompson posted:

<snip tripe>

Richard Heathfield posted:

<snip tripe>

Since the two self-proclaimed masters of this newsgroup won't reply to me,

I'm also a self-proclaimed master of this newsgroup and I'm replying to you
here. There is still hope

[Clever Monkey]

Serve Laurijssen wrote:

"Frederick Gotham" <fg*******@SPAM .comwrote in message
news:8e******** ***********@new s.indigo.ie...

>Keith Thompson posted:

<snip tripe>

Richard Heathfield posted:

<snip tripe>

Since the two self-proclaimed masters of this newsgroup won't reply to me,

I'm also a self-proclaimed master of this newsgroup and I'm replying to you
here. There is still hope

"I'm in charge, here."

[Keith Thompson]

"Serve Laurijssen" <se*@n.tkwrites :

"Frederick Gotham" <fg*******@SPAM .comwrote in message
news:8e******** ***********@new s.indigo.ie...

>Keith Thompson posted:

<snip tripe>

Richard Heathfield posted:

<snip tripe>

Since the two self-proclaimed masters of this newsgroup won't reply to me,

I'm also a self-proclaimed master of this newsgroup and I'm replying to you
here. There is still hope

You're a bit late. The article to which you're replying was posted on
October 24. Frederick Gotham apologized handsomely for his earlier
behavior on November 11, and has been quite untrollish since then
(though he hasn't posted here in about a month).

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[Kenny McCormack]

In article <ln************ @nuthaus.mib.or g>,
Keith Thompson <ks***@mib.orgw rote:

>"Serve Laurijssen" <se*@n.tkwrites :

>"Frederick Gotham" <fg*******@SPAM .comwrote in message
news:8e******* ************@ne ws.indigo.ie...

>>Keith Thompson posted:

<snip tripe>

Richard Heathfield posted:

<snip tripe>

Since the two self-proclaimed masters of this newsgroup won't reply to me,

I'm also a self-proclaimed master of this newsgroup and I'm replying to you
here. There is still hope

You're a bit late. The article to which you're replying was posted on
October 24. Frederick Gotham apologized handsomely for his earlier
behavior on November 11, and has been quite untrollish since then
(though he hasn't posted here in about a month).

I think it was pretty well established at the time that those "apologies"
were forged by the "regulars".

[Keith Thompson]

Keith Thompson <ks***@mib.orgw rites:
[...]

You're a bit late. The article to which you're replying was posted on
October 24. Frederick Gotham apologized handsomely for his earlier
behavior on November 11, and has been quite untrollish since then
(though he hasn't posted here in about a month).

And there's been zero evidence that his apology was anything other
than genuine (if it were forged, Frederick would have had ample
opportunity to say so).

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[Richard Heathfield]

Kenny McCormack said:

In article <ln************ @nuthaus.mib.or g>,
Keith Thompson <ks***@mib.orgw rote:

<snip>

>>You're a bit late. The article to which you're replying was posted on
October 24. Frederick Gotham apologized handsomely for his earlier
behavior on November 11, and has been quite untrollish since then
(though he hasn't posted here in about a month).

I think it was pretty well established at the time that those "apologies"
were forged by the "regulars".

Mr McCormack is incorrect, as usual.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.

[CBFalconer]

Clever Monkey wrote:

Serve Laurijssen wrote:

>"Frederick Gotham" <fg*******@SPAM .comwrote in message

.... snip ...

>>>
Since the two self-proclaimed masters of this newsgroup won't
reply to me,

I'm also a self-proclaimed master of this newsgroup and I'm
replying to you here. There is still hope

"I'm in charge, here."

"I'm the commander--see, I don't have to explain -- I don't need
to explain why I say things. That's the interesting thing about
being the President. Maybe somebody needs to explain to me why
they say something, but I don't feel like I owe anybody an
explanation." - George W. Bush, 2002-11-19

"I'm a war president. I make decisions here in the Oval Office
in foreign policy matters with war on my mind." - GWB 2004-2-8

"If I knew then what I know today, I would still have invaded
Iraq. It was the right decision" - G.W. Bush, 2004-08-02

"This notion that the United States is getting ready to attack
Iran is simply ridiculous. And having said that, all options
are on the table." - George W. Bush, Brussels, 2005-02-22

Who's in charge?

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home .att.net>

[Richard Bos]

CBFalconer <cb********@yah oo.comwrote:

Clever Monkey wrote:

Serve Laurijssen wrote:

"Frederick Gotham" <fg*******@SPAM .comwrote in message

... snip ...

>>
Since the two self-proclaimed masters of this newsgroup won't
reply to me,

I'm also a self-proclaimed master of this newsgroup and I'm
replying to you here. There is still hope

"I'm in charge, here."

"I'm the commander--see, I don't have to explain -- I don't need
to explain why I say things. That's the interesting thing about
being the President. Maybe somebody needs to explain to me why
they say something, but I don't feel like I owe anybody an
explanation." - George W. Bush, 2002-11-19

"I'm a war president. I make decisions here in the Oval Office
in foreign policy matters with war on my mind." - GWB 2004-2-8

"If I knew then what I know today, I would still have invaded
Iraq. It was the right decision" - G.W. Bush, 2004-08-02

"This notion that the United States is getting ready to attack
Iran is simply ridiculous. And having said that, all options
are on the table." - George W. Bush, Brussels, 2005-02-22

Who's in charge?

Cheney.

Richard