[Bug c/25161] New: Internal compiler error (segfault) instead of error message

[Bug c/25161] New: Internal compiler error (segfault) instead of error message

[gccbug at zevv dot nl]

GCC version :

  4.0.2

Complete C file :

   int a;
   char buf[(int)&a];


command line :

   gcc-4.0 -c file.c

Error message :

  t.c:3: 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.
  For Debian GNU/Linux specific bug reporting instructions,
  see <URL:file:///usr/share/doc/gcc-4.0/README.Bugs>.


This (Faulty) code gives normal errors with gcc-2.95 and gcc-3.2.3


-- 
           Summary: Internal compiler error (segfault) instead of error
                    message
           Product: gcc
           Version: 4.0.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gccbug at zevv dot nl
 GCC build triplet: i486-linux-gnu
  GCC host triplet: i486-linux-gnu
GCC target triplet: i486-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2005-11-29 20:57 -------
Confirmed.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
  GCC build triplet|i486-linux-gnu              |
   GCC host triplet|i486-linux-gnu              |
 GCC target triplet|i486-linux-gnu              |
           Keywords|                            |ice-on-invalid-code
      Known to fail|4.0.2                       |4.0.2 4.1.0 4.2.0
      Known to work|2.95 3.2.3                  |2.95 3.2.3 3.4.0
   Last reconfirmed|0000-00-00 00:00:00         |2005-11-29 20:57:05
               date|                            |
            Summary|Internal compiler error     |[4.0/4.1/4.2 Regression]
                   |(segfault) instead of error |Internal compiler error
                   |message                     |(segfault) instead of error
                   |                            |message
   Target Milestone|---                         |4.0.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[janis at gcc dot gnu dot org]

------- Comment #2 from janis at gcc dot gnu dot org  2005-11-30 21:33 -------
A regression hunt identified this patch to fix PR c/12913

http://gcc.gnu.org/viewcvs?view=rev&rev=98464

r98464 | jsm28 | 2005-04-20 16:41:48 +0000 (Wed, 20 Apr 2005)


-- 

janis at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jsm28 at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[reichelt at gcc dot gnu dot org]

------- Comment #3 from reichelt at gcc dot gnu dot org  2005-12-05 11:54 -------
Btw, this is a regression from GCC 4.0.0 to GCC 4.0.1.


-- 

reichelt at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|4.0.2 4.1.0 4.2.0           |4.0.1 4.0.2 4.1.0 4.2.0
      Known to work|2.95 3.2.3 3.4.0            |2.95 3.2.3 3.4.0 4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[mmitchel at gcc dot gnu dot org]

------- Comment #4 from mmitchel at gcc dot gnu dot org  2005-12-19 18:45 -------
Since the code is invalid, this is not a huge problem, but still shoudl be
fixed: P2.


-- 

mmitchel at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[steven at gcc dot gnu dot org]

------- Comment #5 from steven at gcc dot gnu dot org  2006-01-08 15:05 -------
Created an attachment (id=10594)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10594&action=view)
Robustify

Ideally we would be able to reject (int)&a as non-constant and therefore
illegal because the storage size of buf isn't constant.  Unfortunately we do
this in finish_decl, which is not called after the point where we fail now.

My hack-around is to deal with label_context_stack_vm==NULL in more places. 
Sadly I have no idea what this variable is for, and Joseph did not add any
comment or documentation of any form for these global variables.
(Ironic: the people who always rightly point out that people should document
what they are doing sometimes fail to document their own work :-)

If there is a way to reject this non-constant _before_ we call
c_begin_vm_scope, that would be the "right" fix AFAICT.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[steven at gcc dot gnu dot org]

------- Comment #6 from steven at gcc dot gnu dot org  2006-01-08 15:09 -------
Of course I mean "[finish_decl] _is_ called after the point where we fail now".
 The error for (int)&a not being a constant is issued from finish_decl, but we
ICE before we call finish_decl for buf.

We ICE during a call to start_decl from c-parser:

1222              else
1223                {
1224                  tree d = start_decl (declarator, specs, false,
1225                                       chainon (postfix_attrs,
1226                                                all_prefix_attrs));
1227                  if (d)
1228                    finish_decl (d, NULL_TREE, asm_name);
1229                }

so we never reach the point where we call finish_decl.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[neil at daikokuya dot co dot uk]

------- Comment #7 from neil at daikokuya dot co dot uk  2006-01-09 04:38 -------
Subject: Re:  [4.0/4.1/4.2 Regression] Internal compiler error (segfault)
instead of error message

steven at gcc dot gnu dot org wrote:-

> Sadly I have no idea what this variable is for, and Joseph did not add any

Detecting jumps over variably modified types as required in C99.

Neil.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

Re: [Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[Neil Booth]

steven at gcc dot gnu dot org wrote:-

> Sadly I have no idea what this variable is for, and Joseph did not add any

Detecting jumps over variably modified types as required in C99.

Neil.

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[joseph at codesourcery dot com]

------- Comment #8 from joseph at codesourcery dot com  2006-01-15 23:52 -------
Subject: Re:  [4.0/4.1/4.2 Regression] Internal compiler error
 (segfault) instead of error message

On Sun, 8 Jan 2006, steven at gcc dot gnu dot org wrote:

> My hack-around is to deal with label_context_stack_vm==NULL in more places. 
> Sadly I have no idea what this variable is for, and Joseph did not add any
> comment or documentation of any form for these global variables.

The documentation is on the structure definition c_label_context_vm (and 
similarly c_label_context_se).

I think fixing pushdecl not to call c_begin_vm_scope if current_scope == 
file_scope should suffice.

> If there is a way to reject this non-constant _before_ we call
> c_begin_vm_scope, that would be the "right" fix AFAICT.

The right fix there would perhaps be in grokdeclarator,

                if (TREE_CODE (size) == INTEGER_CST)
                  {
                    constant_expression_warning (size);
                    if (tree_int_cst_sgn (size) < 0)
                      {
                        error ("size of array %qs is negative", name);
                        size = integer_one_node;
                      }
                  }
                else
                  {
                    /* Make sure the array size remains visibly
                       nonconstant even if it is (eg) a const variable
                       with known value.  */
                    size_varies = 1;

before the "else" have an "else if" case that checks for NORMAL or FIELD 
at file scope, gives an error and uses integer_one_node instead.  This 
should also cause certain other cases we silently accept to be 
unconditionally rejected instead:

int a;
int (*b)[(__SIZE_TYPE__)&a];
  (ICEs at present because of this bug, older GCC accepts silently)

or

int a;
struct s { int b[(__SIZE_TYPE__)&a]; };

or

int a;
struct s { int (*x)[(__SIZE_TYPE__)&a]; };

That way we don't rely on variable_size to give an error (it's not a good 
place to do so anyway, this error belongs in the front end), which won't 
work for TREE_CONSTANT cases such as these addresses.  (All examples 
including the original test ((int) changed to (__SIZE_TYPE__)) should of 
course be added as testcases.)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[mmitchel at gcc dot gnu dot org]

------- Comment #9 from mmitchel at gcc dot gnu dot org  2006-02-24 00:26 -------
This issue will not be resolved in GCC 4.1.0; retargeted at GCC 4.1.1.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.0.3                       |4.1.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[mmitchel at gcc dot gnu dot org]

------- Comment #10 from mmitchel at gcc dot gnu dot org  2006-05-25 02:33 -------
Will not be fixed in 4.1.1; adjust target milestone to 4.1.2.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.1                       |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[jsm28 at gcc dot gnu dot org]

------- Comment #11 from jsm28 at gcc dot gnu dot org  2006-06-04 16:49 -------
Testing a fix.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jsm28 at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2006-02-12 18:03:48         |2006-06-04 16:49:39
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1/4.2 Regression] Internal compiler error (segfault) instead of error message

[jsm28 at gcc dot gnu dot org]

------- Comment #12 from jsm28 at gcc dot gnu dot org  2006-06-05 00:51 -------
Subject: Bug 25161

Author: jsm28
Date: Mon Jun  5 00:51:45 2006
New Revision: 114378

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=114378
Log:
        PR c/25161
        PR c/27020
        * c-decl.c (grokdeclarator): Disallow variably modified types at
        file scope.  Avoid marking shared array type of constant size as
        VLA.

testsuite:
        * gcc.dg/array-10.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/array-10.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-decl.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1 Regression] Internal compiler error (segfault) instead of error message

[jsm28 at gcc dot gnu dot org]

------- Comment #13 from jsm28 at gcc dot gnu dot org  2006-06-05 14:30 -------
Subject: Bug 25161

Author: jsm28
Date: Mon Jun  5 14:29:52 2006
New Revision: 114388

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=114388
Log:
        PR c/25161
        PR c/27020
        * c-decl.c (grokdeclarator): Disallow variably modified types at
        file scope.  Avoid marking shared array type of constant size as
        VLA.

testsuite:
        * gcc.dg/array-10.c: New test.

Added:
    branches/gcc-4_1-branch/gcc/testsuite/gcc.dg/array-10.c
      - copied unchanged from r114387, trunk/gcc/testsuite/gcc.dg/array-10.c
Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/c-decl.c
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1 Regression] Internal compiler error (segfault) instead of error message

[jsm28 at gcc dot gnu dot org]

------- Comment #14 from jsm28 at gcc dot gnu dot org  2006-06-05 16:50 -------
Subject: Bug 25161

Author: jsm28
Date: Mon Jun  5 16:50:45 2006
New Revision: 114394

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=114394
Log:
        PR c/25161
        PR c/27020
        * c-decl.c (grokdeclarator): Disallow variably modified types at
        file scope.  Avoid marking shared array type of constant size as
        VLA.

testsuite:
        * gcc.dg/array-10.c: New test.

Added:
    branches/gcc-4_0-branch/gcc/testsuite/gcc.dg/array-10.c
      - copied unchanged from r114392, trunk/gcc/testsuite/gcc.dg/array-10.c
Modified:
    branches/gcc-4_0-branch/gcc/ChangeLog
    branches/gcc-4_0-branch/gcc/c-decl.c
    branches/gcc-4_0-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1 Regression] Internal compiler error (segfault) instead of error message

[pinskia at gcc dot gnu dot org]

------- Comment #15 from pinskia at gcc dot gnu dot org  2006-06-05 17:33 -------
Fixed in 4.0.4 and 4.1.2.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to work|2.95 3.2.3 3.4.0 4.0.0 4.2.0|2.95 3.2.3 3.4.0 4.0.0 4.2.0
                   |                            |4.0.4 4.1.2
         Resolution|                            |FIXED
   Target Milestone|4.1.2                       |4.0.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161

[Bug c/25161] [4.0/4.1 Regression] Internal compiler error (segfault) instead of error message

[pinskia at gcc dot gnu dot org]

------- Comment #16 from pinskia at gcc dot gnu dot org  2006-12-16 18:31 -------
*** Bug 30231 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mikhail dot vorozhtsov at
                   |                            |gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25161