[Bug preprocessor/24202] New: Segfault with #pragma once

[Bug preprocessor/24202] New: Segfault with #pragma once

[debian-gcc at lists dot debian dot org]

[ forwarded from http://bugs.debian.org/bug=330857 ]

unpacking the attached tarball and cpp -I.. -I. test.c gives:

% cpp -I.. -I. test.c
# 1 "test.c"
# 0 "<built-in>"
# 1 "<command line>"
# 1 "test.c"
# 1 "../tao/ORB.h" 1
# 1 "../tao/Sequence_T.h" 1


# 1 "../tao/Sequence.h" 1


# 1 "../tao/Sequence_T.h" 1
# 4 "../tao/Sequence.h" 2
# 4 "../tao/Sequence_T.h" 2

# 1 "../tao/Sequence_T.cpp" 1
# 6 "../tao/Sequence_T.h" 2
# 1 "../tao/ORB.h" 2
# 2 "test.c" 2
<built-in>:0: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.


-- 
           Summary: Segfault with #pragma once
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: debian-gcc at lists dot debian dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] Segfault with #pragma once

[debian-gcc at lists dot debian dot org]

------- Comment #1 from debian-gcc at lists dot debian dot org  2005-10-04 21:59 -------
Created an attachment (id=9882)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=9882&action=view)
Test case


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [4.1 Regression] Segfault with #pragma once

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2005-10-04 23:05 -------
Hmm, I think this is related to PR 15167.

This worked with "4.0.0 20050225" and "3.5.0 20040909".

Though it failed with "3.4.0 20040116" and 3.4.0 release and the current
mainline.

I am going to mark this currently as a 4.1 regression but not confirm it until
I can get a newer 4.0.x and 3.4.x though I will fill out the known to work/fail
for releases I tried.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
      Known to fail|                            |3.4.0 4.1.0
      Known to work|                            |3.3.3
            Summary|Segfault with #pragma once  |[4.1 Regression] Segfault
                   |                            |with #pragma once
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [4.1 Regression] Segfault with #pragma once

[janis187 at us dot ibm dot com]

------- Comment #3 from janis187 at us dot ibm dot com  2005-10-06 22:21 -------
The list of work/fail versions is very odd for this bug; it seems to have
worked on mainline until sometime between 20050828 and 20050904.  3.3.5 passes,
but all 3.4.x versions I tried fail.  4.0.0 passes but 4.0.2 fails.

I fired off several mainline builds between the 3.3 branchpoint and early
September to identify ranges on mainline where it passes and fails; those
should help show if it's an intermittent failure or has definite fix and
break points.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [4.1 Regression] Segfault with #pragma once

[janis187 at us dot ibm dot com]

------- Comment #4 from janis187 at us dot ibm dot com  2005-10-07 19:45 -------
The most recent break on mainline was by this patch from jakub:

  http://gcc.gnu.org/ml/gcc-cvs/2005-08/msg00974.html

The same patch was applied to the 4.0 branch, causing the failure in 4.0.2.

That patch from Jakub reverted part of this patch from Zack, which had fixed
this bug on mainline:

  http://gcc.gnu.org/ml/gcc-cvs/2004-06/msg00122.html

Before that, the failure on mainline started sometime between 2003-07-16 and
2003-09-15.  I can identify the patch if it would be useful to anyone.


-- 

janis187 at us dot ibm dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [4.0/4.1 Regression] Segfault with #pragma once

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2005-10-07 19:50 -------
(In reply to comment #4)
> Before that, the failure on mainline started sometime between 2003-07-16 and
> 2003-09-15.  I can identify the patch if it would be useful to anyone.

Hmm, can you because in PR 15167, Neil said:
>If it was broken back around 5th August 2003 I will look into this, as it was my
>new code.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|3.4.0 4.1.0                 |3.4.0 4.1.0 4.0.2
      Known to work|3.3.3                       |3.3.3 4.0.1 4.0.0
            Summary|[4.1 Regression] Segfault   |[4.0/4.1 Regression]
                   |with #pragma once           |Segfault with #pragma once
   Target Milestone|4.1.0                       |4.0.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [4.0/4.1 Regression] Segfault with #pragma once

[pinskia at gcc dot gnu dot org]

------- Comment #6 from pinskia at gcc dot gnu dot org  2005-10-08 13:37 -------
*** Bug 24271 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |lothar at tradescape dot biz


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [4.0/4.1 Regression] Segfault with #pragma once

[janis at gcc dot gnu dot org]

------- Comment #7 from janis at gcc dot gnu dot org  2005-10-08 22:10 -------
A regression test identified this patch from Neil on 2003-08-02 as thene start
of failures:

  http://gcc.gnu.org/ml/gcc-cvs/2003-08/msg00093.html



-- 

janis at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [4.0/4.1 Regression] Segfault with #pragma once

[janis at gcc dot gnu dot org]

------- Comment #8 from janis at gcc dot gnu dot org  2005-10-08 22:11 -------
Hmm, "regression test" in the last comment should have been "regression hunt".


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4/4.0/4.1 Regression] Segfault with #pragma once

[mmitchel at gcc dot gnu dot org]

------- Comment #9 from mmitchel at gcc dot gnu dot org  2005-10-31 06:02 -------
I'm marking this as P1, at least until we do some analysis.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4/4.0/4.1 Regression] Segfault with #pragma once

[wilson at gcc dot gnu dot org]

------- Comment #10 from wilson at gcc dot gnu dot org  2005-11-01 07:19 -------
On mainline, this appears to be fixable with a one line patch.

We are failing in should_stack_file because we have a _cpp_file struct with
buffer=0 and buffer_valid=1.  We call read_file which immediately returns
because buffer_valid is true.  Then we try to read chars from the buffer and
crash because it is still zero.

The trivial fix is that we must clear buffer_valid when we clear buffer.  This
is done in _cpp_pop_file_buffer.  The testcase works with this patch.

I haven't looked at any of the patch history or at the older gcc versions yet.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4/4.0/4.1 Regression] Segfault with #pragma once

[wilson at gcc dot gnu dot org]

------- Comment #11 from wilson at gcc dot gnu dot org  2005-11-01 07:22 -------
Created an attachment (id=10096)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10096&action=view)
clear buffer_valid when clearing buffer

Untested patch for mainline which makes the testcase work.


-- 

wilson at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |wilson at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4/4.0/4.1 Regression] Segfault with #pragma once

[wilson at gcc dot gnu dot org]

------- Comment #12 from wilson at gcc dot gnu dot org  2005-11-01 07:25 -------
The patch should use false instead of 0.  These new fangled boolean types keep
messing me up.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4/4.0/4.1 Regression] Segfault with #pragma once

[wilson at gcc dot gnu dot org]

------- Comment #13 from wilson at gcc dot gnu dot org  2005-11-01 23:51 -------
I believe the problem originated here:
2003-07-29  Neil Booth  <neil@daikokuya.co.uk>

        PR preprocessor/11569
        PR preprocessor/11649
        * Makefile.in (LIBCPP_DEPS): Add HASHTAB_H.
        * cppfiles.c: Completely rewritten.
        ...

This added the buffer_valid field, and added code that clears buffer without
also clearing buffer_valid.  This is revision 1.178 in the gcc/cppfiles.c file.

The failure occurs only when we free a valid buffer, and then try to reuse that
buffer because we still think it is valid.  Whether this occurs depends on how
buffers are managed by cpp, and how they are used by cpp, so I don't find it
surprising that this latent bug has been disappearing and reappearing over
time.  The patch identified by Janis just makes the problem more visible
because it adds more uses of buffer_valid.

Now I'm off to test my patch.  The same patch should work for all 3 gcc
versions.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4/4.0/4.1 Regression] Segfault with #pragma once

[wilson at gcc dot gnu dot org]

------- Comment #14 from wilson at gcc dot gnu dot org  2005-11-04 02:10 -------
Subject: Bug 24202

Author: wilson
Date: Fri Nov  4 02:10:19 2005
New Revision: 106472

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=106472
Log:
Fix failure with pragma once where buffer is NULL and buffer_valid is true.
PR preprocessor/24202
* files.c (_cpp_pop_file_buffer): Set buffer_valid to false.

Modified:
    trunk/libcpp/ChangeLog
    trunk/libcpp/files.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4/4.0/4.1 Regression] Segfault with #pragma once

[wilson at gcc dot gnu dot org]

------- Comment #15 from wilson at gcc dot gnu dot org  2005-11-04 02:12 -------
Subject: Bug 24202

Author: wilson
Date: Fri Nov  4 02:12:48 2005
New Revision: 106473

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=106473
Log:
Fix pragma once bug where buffer is NULL and buffer_valid is true.
PR preprocessor/24202
* files.c (_cpp_pop_file_buffer): Set buffer_valid to false.

Modified:
    branches/gcc-4_0-branch/libcpp/ChangeLog
    branches/gcc-4_0-branch/libcpp/files.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4 Regression] Segfault with #pragma once

[pinskia at gcc dot gnu dot org]

------- Comment #16 from pinskia at gcc dot gnu dot org  2005-11-04 04:42 -------
Fixed on the mainline and the 4.0 branch for 4.0.3 but is waiting for a back
port for 3.4.x.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|3.3.3 4.0.1 4.0.0           |3.3.3 4.0.1 4.0.0 4.0.3
                   |                            |4.1.0
            Summary|[3.4/4.0/4.1 Regression]    |[3.4 Regression] Segfault
                   |Segfault with #pragma once  |with #pragma once
   Target Milestone|4.0.3                       |3.4.6


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4 Regression] Segfault with #pragma once

[gdr at gcc dot gnu dot org]

------- Comment #17 from gdr at gcc dot gnu dot org  2006-03-01 10:11 -------
Subject: Bug 24202

Author: gdr
Date: Wed Mar  1 10:11:05 2006
New Revision: 111599

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=111599
Log:
Backport Jim Wilson's patch for PR 24202

Modified:
    branches/gcc-3_4-branch/gcc/ChangeLog
    branches/gcc-3_4-branch/gcc/cppfiles.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202

[Bug preprocessor/24202] [3.4 Regression] Segfault with #pragma once

[gdr at gcc dot gnu dot org]

------- Comment #18 from gdr at gcc dot gnu dot org  2006-03-01 10:11 -------
patch backported to 3.4.6.


-- 

gdr at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24202