[Bug fortran/33375] New: ICE (segfault) gfortran.dg/common_6.f90

[Bug fortran/33375] New: ICE (segfault) gfortran.dg/common_6.f90

[burnus at gcc dot gnu dot org]

With 4.3.0 20070910 [trunk revision 128322] I get a segmentation fault when
compiling gfortran.dg/common_6.f90; excerpt:

! PR 23765 : We used to incorrectly accept common blocks with no symbols
common          ! { dg-error "Syntax error" }
common y/d/     ! { dg-error "Syntax error" }

The crash happens in: resolve_common_blocks

  for (csym = common_root->n.common->head; csym; csym = csym->common_next)
    {
      if (csym->ts.type == BT_DERIVED
          && !(csym->ts.derived->attr.sequence
               || csym->ts.derived->attr.is_bind_c))

When the error happens:
(gdb) p csym->ts
$9 = {type = 0, kind = 0, derived = 0x0, cl = 0x0, is_c_interop = 6,
  is_iso_c = 1, f90_type = BT_UNKNOWN}

I don't understand why "csym->ts.derived->attr" is evaluated as "csym->ts.type
!= BT_DERIVED". ???


-- 
           Summary: ICE (segfault) gfortran.dg/common_6.f90
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug middle-end/33375] [4.3 Regression] ICE (segfault) gfortran.dg/common_6.f90

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2007-09-10 08:54 -------
The regression occurred between (working)
  gcc version 4.3.0 20070906 (experimental) [trunk revision 128175] (GCC)
and
  gcc version 4.3.0 20070907 (experimental) [trunk revision 128228] (GCC)
on x86_64-unknown-linux-gnu.

As I cannot find any gcc/fortran/* change which could have caused this, I
assign it to the middle end.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|fortran                     |middle-end
            Summary|ICE (segfault)              |[4.3 Regression] ICE
                   |gfortran.dg/common_6.f90    |(segfault)
                   |                            |gfortran.dg/common_6.f90
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] [4.3 Regression] ICE (segfault) gfortran.dg/common_6.f90

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2007-09-10 16:00 -------
Back to fortran; I was wrong. This is not a regression, but it occurred from
the beginning as valgrind shows. That it crashes is new, however.


More debugging; the line:
  common /b/x/c/  ! { dg-error "Syntax error" }
is matched properly in gfc_match_common: sym->name is "x" and the typespec
looks ok as well.

However, in resolve_common_blocks:
  for (csym = common_root->n.common->head; csym; csym = csym->common_next)
    {

(gdb) p csym
$36 = (gfc_symbol *) 0xf475b0
(gdb) p sym->name
Cannot access memory at address 0x0
(gdb) p sym->ts
Cannot access memory at address 0x20

Thus something corrupts the symbol in between.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|middle-end                  |fortran


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] [4.3 Regression] ICE (segfault) gfortran.dg/common_6.f90

[fxcoudert at gcc dot gnu dot org]

-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-09-17 09:27:20
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[danglin at gcc dot gnu dot org]

------- Comment #3 from danglin at gcc dot gnu dot org  2007-09-29 20:42 -------
Also occurs on hppa64-hp-hpux11.11.


-- 

danglin at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[tobi at gcc dot gnu dot org]

------- Comment #4 from tobi at gcc dot gnu dot org  2007-10-07 20:03 -------
If we reject the common as syntactically wrong, it should never be resolved.


-- 

tobi at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[burnus at gcc dot gnu dot org]

------- Comment #5 from burnus at gcc dot gnu dot org  2008-01-06 21:50 -------
*** Bug 34693 has been marked as a duplicate of this bug. ***


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hjl at lucon dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[burnus at gcc dot gnu dot org]

------- Comment #6 from burnus at gcc dot gnu dot org  2008-01-06 22:23 -------
*** Bug 34693 has been marked as a duplicate of this bug. ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[hjl at lucon dot org]

------- Comment #7 from hjl at lucon dot org  2008-01-07 04:57 -------
gfc_undo_symbols has

 for (p = changed_syms; p; p = q) 
    {    
      q = p->tlink;

      if (p->new)
        {    
          /* Symbol was new.  */
          delete_symtree (&p->ns->sym_root, p->name);

          p->refs--;
          if (p->refs < 0) 
            gfc_internal_error ("gfc_undo_symbols(): Negative refs");
          if (p->refs == 0)
            gfc_free_symbol (p);
          continue;
        }

"P" is freed. But it still accessible by resolve_common_vars somehow.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[burnus at gcc dot gnu dot org]

------- Comment #8 from burnus at gcc dot gnu dot org  2008-01-07 07:48 -------
*** Bug 34698 has been marked as a duplicate of this bug. ***


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ismail at pardus dot org dot
                   |                            |tr


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[hjl at lucon dot org]

------- Comment #9 from hjl at lucon dot org  2008-01-07 22:57 -------
We are processing common block symbols which we have rejected/freed before.
This patch works for me:

Index: symbol.c
===================================================================
--- symbol.c    (revision 131352)
+++ symbol.c    (working copy)
@@ -2726,14 +2726,14 @@ gfc_commit_symbol (gfc_symbol *sym)
 /* Recursive function that deletes an entire tree and all the common
    head structures it points to.  */

-static void
-free_common_tree (gfc_symtree * common_tree)
+void
+gfc_free_common_tree (gfc_symtree * common_tree)
 {
   if (common_tree == NULL)
     return;

-  free_common_tree (common_tree->left);
-  free_common_tree (common_tree->right);
+  gfc_free_common_tree (common_tree->left);
+  gfc_free_common_tree (common_tree->right);

   gfc_free (common_tree);
 }  
@@ -2863,7 +2863,7 @@ gfc_free_namespace (gfc_namespace *ns)

   free_sym_tree (ns->sym_root);
   free_uop_tree (ns->uop_root);
-  free_common_tree (ns->common_root);
+  gfc_free_common_tree (ns->common_root);

   for (cl = ns->cl_list; cl; cl = cl2)
     {
Index: gfortran.h
===================================================================
--- gfortran.h  (revision 131352)
+++ gfortran.h  (working copy)
@@ -2137,6 +2137,7 @@ int gfc_symbols_could_alias (gfc_symbol 
 void gfc_undo_symbols (void);
 void gfc_commit_symbols (void);
 void gfc_commit_symbol (gfc_symbol *);
+void gfc_free_common_tree (gfc_symtree *);
 void gfc_free_namespace (gfc_namespace *);

 void gfc_symbol_init_2 (void);
Index: match.c
===================================================================
--- match.c     (revision 131352)
+++ match.c     (working copy)
@@ -2956,6 +2956,8 @@ done:
   return MATCH_YES;

 syntax:
+  gfc_free_common_tree (gfc_current_ns->common_root);
+  gfc_current_ns->common_root = NULL;
   gfc_syntax_error (ST_COMMON);

 cleanup:

I don't know if it is 100% correct.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[jvdelisle at gcc dot gnu dot org]

------- Comment #10 from jvdelisle at gcc dot gnu dot org  2008-01-08 04:16 -------
No longer segfaults on x86-64

Valgrind reports with common_6.f90

==10016== 1,160 bytes in 5 blocks are definitely lost in loss record 2 of 6
==10016==    at 0x4A059F6: malloc (vg_replace_malloc.c:149)
==10016==    by 0xB3FBD7: xmalloc (xmalloc.c:147)
==10016==    by 0x448EC4: gfc_getmem (misc.c:37)
==10016==    by 0x442281: gfc_get_common (match.c:2701)
==10016==    by 0x443F29: gfc_match_common (match.c:2793)
==10016==    by 0x452419: match_word (parse.c:64)
==10016==    by 0x45316F: decode_statement (parse.c:195)
==10016==    by 0x4535F4: next_statement (parse.c:505)
==10016==    by 0x4568E1: gfc_parse_file (parse.c:3317)
==10016==    by 0x47F414: gfc_be_parse_file (f95-lang.c:260)
==10016==    by 0x6F25E4: toplev_main (toplev.c:1042)
==10016==    by 0x3B7EC1E073: (below main) (in /lib64/libc-2.7.so)
==10016== 
==10016== LEAK SUMMARY:
==10016==    definitely lost: 1,160 bytes in 5 blocks.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] ICE (segfault) gfortran.dg/common_6.f90

[hjl at lucon dot org]

------- Comment #11 from hjl at lucon dot org  2008-01-08 13:56 -------
A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2008-01/msg00294.html


-- 

hjl at lucon dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2008-
                   |                            |01/msg00294.html


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] [4.3 Regression] ICE (segfault) gfortran.dg/common_6.f90

[rguenth at gcc dot gnu dot org]

------- Comment #12 from rguenth at gcc dot gnu dot org  2008-01-16 15:25 -------
I still see it on x86_64-linux.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |error-recovery
           Priority|P3                          |P5
            Summary|ICE (segfault)              |[4.3 Regression] ICE
                   |gfortran.dg/common_6.f90    |(segfault)
                   |                            |gfortran.dg/common_6.f90


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] [4.3 Regression] ICE (segfault) gfortran.dg/common_6.f90

[hjl at gcc dot gnu dot org]

------- Comment #13 from hjl at gcc dot gnu dot org  2008-01-18 01:29 -------
Subject: Bug 33375

Author: hjl
Date: Fri Jan 18 01:29:11 2008
New Revision: 131621

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=131621
Log:
2008-01-17  H.J. Lu  <hongjiu.lu@intel.com>

        PR fortran/33375
        * symbol.c (free_common_tree): Renamed to ...
        (gfc_free_common_tree): This.  Remove static.
        (gfc_free_namespace): Updated.

        * gfortran.h (gfc_free_common_tree): New.

        * match.c (gfc_match_common): Call gfc_free_common_tree () with
        gfc_current_ns->common_root and set gfc_current_ns->common_root
        to NULL on syntax error.

Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/match.c
    trunk/gcc/fortran/symbol.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] [4.3 Regression] ICE (segfault) gfortran.dg/common_6.f90

[ubizjak at gmail dot com]

------- Comment #14 from ubizjak at gmail dot com  2008-01-18 08:05 -------
Fixed.


-- 

ubizjak at gmail dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375

[Bug fortran/33375] [4.3 Regression] ICE (segfault) gfortran.dg/common_6.f90

[dfranke at gcc dot gnu dot org]

------- Comment #15 from dfranke at gcc dot gnu dot org  2008-01-24 21:37 -------
Subject: Bug 33375

Author: dfranke
Date: Thu Jan 24 21:36:14 2008
New Revision: 131811

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=131811
Log:
2008-01-24  Daniel Franke  <franke.daniel@gmail.com>

        PR fortran/33375
        PR fortran/34858
        * gfortran.h: Revert changes from 2008-01-17.
        * match.c: Likewise.
        * symbol.c: Likewise.
        (gfc_undo_symbols): Undo namespace changes related to common blocks.


Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/match.c
    trunk/gcc/fortran/symbol.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33375