[Bug preprocessor/28709] New: [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens with ##

[Bug preprocessor/28709] New: [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens with ##

[reichelt at gcc dot gnu dot org]

The following invalid code snippet generates a bogus error message since
GCC 3.1:

==========================
#define foo - ## >>
foo;
==========================

bug.c:2:1: error: pasting "->" and ">>" does not give a valid preprocessing
token
bug.c:2: error: expected identifier or '(' before '->' token

The problem is that we tried to paste "-" and ">>" and not "->" and ">>".
GCC 3.0.x produced a correct diagnostic.


-- 
           Summary: [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens
                    with ##
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Keywords: diagnostic, monitored
          Severity: normal
          Priority: P3
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: reichelt at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens with ##

[reichelt at gcc dot gnu dot org]

-- 

reichelt at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.0.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens with ##

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |minor


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens with ##

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jakub at gcc dot gnu dot org
                   |dot org                     |
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2006-
                   |                            |08/msg00548.html
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-08-16 16:19:10
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens with ##

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens with ##

[mmitchel at gcc dot gnu dot org]

------- Comment #1 from mmitchel at gcc dot gnu dot org  2006-10-11 22:30 -------
This patch is OK, thanks.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1/4.2 regression] Bad diagnostic pasting tokens with ##

[jakub at gcc dot gnu dot org]

------- Comment #2 from jakub at gcc dot gnu dot org  2006-10-12 09:26 -------
Subject: Bug 28709

Author: jakub
Date: Thu Oct 12 09:25:59 2006
New Revision: 117664

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=117664
Log:
        PR preprocessor/28709
        * macro.c (paste_tokens): Do error reporting here, use BUF with the
        spelled LHS token as opposed to spelling it again.
        (paste_all_tokens): Don't report errors here, just break on failure.

        * gcc.dg/cpp/paste14.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/cpp/paste14.c
Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/libcpp/ChangeLog
    trunk/libcpp/macro.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[reichelt at gcc dot gnu dot org]

------- Comment #3 from reichelt at gcc dot gnu dot org  2006-10-23 20:41 -------
Just a minor nit: The second error message still contains the "->" token
which should not have been generated. But that's probably tolerable.

bug.c:2:1: error: pasting "-" and ">>" does not give a valid preprocessing
token
bug.c:2: error: expected identifier or '(' before '->' token


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[tromey at gcc dot gnu dot org]

------- Comment #4 from tromey at gcc dot gnu dot org  2006-12-28 04:22 -------
FWIW what happens here is that 'foo;' is turned into
'-> >>;' by cpp; then the second error is emitted by the
C parser.  You can easily see this by comparing the -E output
against the --syntax-only output.

The problem here is that paste_tokens backs up over
the '>>' token, but it leaves the half-pasted '->' token
in *plhs.  I have a fix that I'm testing.


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[patchapp at dberlin dot org]

------- Comment #5 from patchapp at dberlin dot org  2007-01-01 21:57 -------
Subject: Bug number PR preprocessor/28709

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2006-12/msg01852.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[gdr at gcc dot gnu dot org]

------- Comment #6 from gdr at gcc dot gnu dot org  2007-02-03 18:54 -------
Won't fix in GCC-4.0.x.  Adjusting milestone.


-- 

gdr at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.0.4                       |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.3                       |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.2                       |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[ahs3 at fc dot hp dot com]

------- Comment #7 from ahs3 at fc dot hp dot com  2007-03-07 00:49 -------
Is this code snippet related to this bug, or a new one entirely?

------------------------------------------------
#define LABEL(a, b) a##b##:

int main () {
LABEL(all,done)
   return 0;
}
------------------------------------------------

If I compile it:

$ gcc -o foo.o foo.c
foo.c:4:1: error: pasting "alldone" and ":" does not give a valid preprocessing
token

However, if I use -E first, and compile the result, the snippet compiles
properly,


-- 

ahs3 at fc dot hp dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ahs3 at fc dot hp dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[pinskia at gcc dot gnu dot org]

------- Comment #8 from pinskia at gcc dot gnu dot org  2007-03-07 00:58 -------
(In reply to comment #7)
> Is this code snippet related to this bug, or a new one entirely?
Actually the error message is fully correct in that case.

> $ gcc -o foo.o foo.c
> foo.c:4:1: error: pasting "alldone" and ":" does not give a valid preprocessing
> token
> 
> However, if I use -E first, and compile the result, the snippet compiles
> properly,

I don't, I get an error even with -E on the mainline, 3.3.5, and 4.0.2:
gcc t.c -E -o t.i
t.c:4:1: error: pasting "alldone" and ":" does not give a valid preprocessing
token


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[ahs3 at fc dot hp dot com]

------- Comment #9 from ahs3 at fc dot hp dot com  2007-03-07 18:43 -------
Ah, my fault; I wasn't being clear.  I still get the error message with -E,
that is true.  However, the resulting code from cpp I thought was correct -- it
just produces what I thought was a normal C label, and if I ignore the error
message, I can compile the output from -E just fine.  It seems to me that if
cpp no longer recognizes ##, then the message should say so ('deprecated cpp
token', or something); if cpp does recognize ##, then I don't think the error
message should  be produced at all since the resulting tokens ('alldone:') are
valid C source.

If none of those are the case, what bit of info am I not understanding?  And
I'm still not sure this is the same bug as the original report -- it seems
similar, but let me know if it's something different entirely.

Thanks.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[pinskia at gcc dot gnu dot org]

------- Comment #10 from pinskia at gcc dot gnu dot org  2007-03-07 21:39 -------
(In reply to comment #9)> 
> If none of those are the case, what bit of info am I not understanding?

Yes "alldone:" are really two seperate tokens in C :).
If you change the definition of LABEL to:
#define LABEL(a, b) a##b :

it works exactly the same as you want it to work.

And yes it is unrelated to this bug really.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[tromey at gcc dot gnu dot org]

------- Comment #11 from tromey at gcc dot gnu dot org  2007-04-25 01:29 -------
*** Bug 31182 has been marked as a duplicate of this bug. ***


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dsb at boyski dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[tromey at gcc dot gnu dot org]

------- Comment #13 from tromey at gcc dot gnu dot org  2007-05-02 20:34 -------
I checked in the follow-up patch to the trunk.
So this fully works on 4.3.


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|4.2.0                       |4.2.0 4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[tromey at gcc dot gnu dot org]

------- Comment #12 from tromey at gcc dot gnu dot org  2007-05-02 20:33 -------
Subject: Bug 28709

Author: tromey
Date: Wed May  2 19:33:44 2007
New Revision: 124356

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124356
Log:
libcpp
        PR preprocessor/28709:
        * macro.c (paste_tokens): Remove PASTE_LEFT from the old lhs.
gcc/testsuite
        PR preprocessor/28709:
        * gcc.dg/cpp/pr28709.c: New file.

Added:
    trunk/gcc/testsuite/gcc.dg/cpp/pr28709.c
Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/libcpp/ChangeLog
    trunk/libcpp/macro.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.0/4.1 regression] Bad diagnostic pasting tokens with ##

[jakub at gcc dot gnu dot org]

------- Comment #14 from jakub at gcc dot gnu dot org  2007-06-26 11:44 -------
Subject: Bug 28709

Author: jakub
Date: Tue Jun 26 11:43:50 2007
New Revision: 126021

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=126021
Log:
        PR preprocessor/28709
        * macro.c (paste_tokens): Do error reporting here, use BUF with the
        spelled LHS token as opposed to spelling it again.
        (paste_all_tokens): Don't report errors here, just break on failure.

        * gcc.dg/cpp/paste14.c: New test.

Added:
    branches/redhat/gcc-4_1-branch/gcc/testsuite/gcc.dg/cpp/paste14.c
Modified:
    branches/redhat/gcc-4_1-branch/gcc/testsuite/ChangeLog
    branches/redhat/gcc-4_1-branch/libcpp/ChangeLog
    branches/redhat/gcc-4_1-branch/libcpp/macro.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709

[Bug preprocessor/28709] [4.1 regression] Bad diagnostic pasting tokens with ##

[jsm28 at gcc dot gnu dot org]

------- Comment #15 from jsm28 at gcc dot gnu dot org  2008-07-04 15:49 -------
Closing 4.1 branch.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to fail|                            |4.1.3
         Resolution|                            |FIXED
   Target Milestone|4.1.3                       |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28709