[Bug preprocessor/36453] New: PR36320 breaks boost

[Bug preprocessor/36453] New: PR36320 breaks boost

[mueller at gcc dot gnu dot org]

testcase:

=== Cut ===
#if !defined(BOOST_PP_IS_ITERATING)

#elif BOOST_PP_ITERATION_DEPTH() == 1
#endif
=== Cut ===

error: missing binary operator before token "("


from reading the PR36320, this behaviour doesn't seem to be intended. It was
intended to only add a check for non-null argument.


-- 
           Summary: PR36320 breaks boost
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mueller at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[rguenth at gcc dot gnu dot org]

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rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at redhat dot com
OtherBugsDependingO|                            |36320
              nThis|                            |
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-06-06 20:03:39
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[tromey at gcc dot gnu dot org]

------- Comment #1 from tromey at gcc dot gnu dot org  2008-06-06 20:23 -------
By my reading of the standard, issuing an error here is correct.
The restrictions on #elif are only lifted if it is in a skipped group.
But, in this case, it is not.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[mueller at gcc dot gnu dot org]

------- Comment #2 from mueller at gcc dot gnu dot org  2008-06-10 22:14 -------
so the code should be changed to

#elif defined(BOOST_PP_ITERATION_DEPTH) && BOOST_PP_ITERATION_DEPTH() == 1

?

it is confusing that #elif behaves more like "#if" and not like "#else\n#if"


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[tromey at gcc dot gnu dot org]

------- Comment #3 from tromey at gcc dot gnu dot org  2008-07-06 03:25 -------
Sorry, I somehow missed the followup comment.

>> #elif defined(BOOST_PP_ITERATION_DEPTH) && BOOST_PP_ITERATION_DEPTH() == 1

The expression has to be valid after preprocessing.
So, if BOOST_PP_ITERATION_DEPTH is not defined, this will yield an error.

>> it is confusing that #elif behaves more like "#if" and not like "#else\n#if"

I agree, but by my reading this is what the standard actually says.
I am open to arguments contrariwise, or to rulings from gcc developers more
expert at standardese than I.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[mueller at gcc dot gnu dot org]

------- Comment #4 from mueller at gcc dot gnu dot org  2008-07-07 09:25 -------
well, lets keep it at that for now


-- 

mueller at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[schwab at suse dot de]

------- Comment #5 from schwab at suse dot de  2008-09-14 08:08 -------
*** Bug 37518 has been marked as a duplicate of this bug. ***


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schwab at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rwgk at yahoo dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[schwab at suse dot de]

------- Comment #6 from schwab at suse dot de  2008-10-09 14:46 -------
*** Bug 37781 has been marked as a duplicate of this bug. ***


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schwab at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jarda at grisoft dot cz


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[sam at gcc dot gnu dot org]

------- Comment #7 from sam at gcc dot gnu dot org  2008-10-09 20:39 -------
Note that this has been fixed in Boost SVN repository recently
(http://svn.boost.org/trac/boost/ticket/2069).


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[rguenth at gcc dot gnu dot org]

------- Comment #8 from rguenth at gcc dot gnu dot org  2008-12-05 12:20 -------
*** Bug 38161 has been marked as a duplicate of this bug. ***


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rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |h dot b dot furuseth at usit
                   |                            |dot uio dot no


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[knocte at gmail dot com]

------- Comment #9 from knocte at gmail dot com  2010-05-06 18:02 -------
Hello.

I'm in a position in which I cannot upgrade my Boost libraries right now.

So, is there a way that I can tell gcc to ignore this warning for now?

Thanks in advance.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453

[Bug preprocessor/36453] PR36320 breaks boost

[rguenther at suse dot de]

------- Comment #10 from rguenther at suse dot de  2010-05-07 08:39 -------
Subject: Re:  PR36320 breaks boost

On Thu, 6 May 2010, knocte at gmail dot com wrote:

> ------- Comment #9 from knocte at gmail dot com  2010-05-06 18:02 -------
> Hello.
> 
> I'm in a position in which I cannot upgrade my Boost libraries right now.
> 
> So, is there a way that I can tell gcc to ignore this warning for now?

No.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36453