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From: Reza Roboubi <reza@parvan.net>
To: David Sveningsson <ext@sidvind.com>,  gcc-help@gcc.gnu.org
Subject: Re: inconsistent macro behavior
Date: Mon, 28 Jul 2008 12:57:00 -0000	[thread overview]
Message-ID: <488DB86E.3010909@parvan.net> (raw)
In-Reply-To: <488D68C3.9090404@sidvind.com>

David Sveningsson wrote:
>> The questions are:
>> a.)  What's even going on here?  Why the apparent inconsistency?
>> b.)  What _should_ be the correct behavior, both in terms of the
>> (extended) GNU C language, and also the standard C language?

> 
> I believe that each c-style string must be encapsulated with " even for 
> the preprocessor to work. Actually, at least gcc-4.3 emits warnings 
> about missing termination for both line 1 and 2 in your test case.
> 
> Perhaps you could work something out with the ## concatenation operator?

Thanks for your replies.

So, double quotes are needed, but I'm still wondering why these behave 
differently:
$ gcc -Wall -E test.c
$ gcc -Wall -c test.c

I mean, what does the gcc back end do _differently_ for those two commands?
---------------------------------------
As a side note, I just checked Torvalds' sparse compiler, and 
interestingly, it returns:

test.c:2:1: warning: Newline in string or character constant
char * c = "llll\n#define y " y ;

In other words, it is amalgamating lines 1+2 into a single string 
literal.  However, sparse does this consistently, regardless of of 
whether I use sparse -E or sparse -c.  So, I can understand what it's doing.

Reza.

  reply	other threads:[~2008-07-28 12:14 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-28  7:29 Reza Roboubi
2008-07-28  8:36 ` David Sveningsson
2008-07-28 12:57   ` Reza Roboubi [this message]
2008-07-28 12:28 ` Reza Roboubi
     [not found] <1217227025.3398.ezmlm@gcc.gnu.org>
2008-07-28  8:41 ` Jay

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