[Bug debug/29614] New: DWARF information for function static variable is missing after unrelated code addition

[Bug debug/29614] New: DWARF information for function static variable is missing after unrelated code addition

[fnf at specifixinc dot com]

A bunch of tests in the gdb testsuite dealing with static variables inside
function scopes have started failing recently with the latest development gcc. 
I simplified the test case down to a small program that shows that simply
adding a small bit of unrelated code causes the DWARF information to disappear.
 Here is a typescript:

Script started on Tue 24 Oct 2006 08:58:44 PM MST
$ cat b.c
int bar ()
{
  static int funclocal = 4;     /* In data section */
  return funclocal;
}

int foo ()
{
  static int funclocal = 3;     /* In Data section */
  return funclocal;
}

#ifdef EXPOSEBUG
void bell ()
{
  static int usedval;
}
#endif

main ()
{
  extern void exit (int);
  exit (bar() + foo());
}
$ gcc -g -o b b.c
$ readelf --debug-dump b | grep funclocal
     DW_AT_name        : (indirect string, offset: 0x0): funclocal
     DW_AT_name        : (indirect string, offset: 0x0): funclocal
     DW_AT_name        : (indirect string, offset: 0x0): funclocal
  0x00000000 66756e63 6c6f6361 6c00              funclocal.
$ gcc -DEXPOSEBUG -g -o b b.c
$ readelf --debug-dump b | grep funclocal
     DW_AT_name        : funclocal
$ gdb b
GNU gdb 6.5.50.20060923-cvs
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...
Using host libthread_db library "/lib/libthread_db.so.1".
(gdb) br foo
Breakpoint 1 at 0x8048361: file b.c, line 10.
(gdb) br bar
Breakpoint 2 at 0x8048357: file b.c, line 4.
(gdb) run
Starting program:
/media/backups/new/build/specifix/experimental/i686-pc-linux-gnu/gdb/gdb/testsuite/b

Breakpoint 2, bar () at b.c:4
4         return funclocal;
(gdb) p funclocal
No symbol "funclocal" in current context.
(gdb) c
Continuing.

Breakpoint 1, foo () at b.c:10
10        return funclocal;
(gdb) p funclocal
$1 = 3
(gdb) quit
The program is running.  Exit anyway? (y or n) y
$ exit

Script done on Tue 24 Oct 2006 08:59:51 PM MST


-- 
           Summary: DWARF information for function static variable is
                    missing after unrelated code addition
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: fnf at specifixinc dot com
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29614

[Bug debug/29614] [4.2/4.3 Regression] DWARF information for function static variable is missing after unrelated code addition

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2006-10-28 18:49 -------
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|i686-pc-linux-gnu           |
   GCC host triplet|i686-pc-linux-gnu           |
           Keywords|                            |wrong-debug
   Last reconfirmed|0000-00-00 00:00:00         |2006-10-28 18:49:28
               date|                            |
            Summary|DWARF information for       |[4.2/4.3 Regression] DWARF
                   |function static variable is |information for function
                   |missing after unrelated code|static variable is missing
                   |addition                    |after unrelated code
                   |                            |addition
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29614

[Bug debug/29614] [4.2/4.3 Regression] DWARF information for function static variable is missing after unrelated code addition

[sje at cup dot hp dot com]

------- Comment #2 from sje at cup dot hp dot com  2006-12-21 23:20 -------
This bug only occurs when NOT in -funit-at-a-time mode.  Is there a plan to
switch all front-ends to unit-at-a-time compilation (which will fix this bug)
or is it still worth coming up with a fix for NON unit-at-a-time usage?  The
problem seems to be when moving declarations from the varpool_nodes_queue to
the varpool_assembled_nodes_queue in varpool_assemble_pending_decls
(varpool.c).  This routine gets called multiple times with a decl and we wind
up putting a declaration on the varpool_assembled_nodes_queue multiple times,
messing up the next_needed links in this linked list.


-- 

sje at cup dot hp dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sje at cup dot hp dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29614

[Bug debug/29614] [4.2/4.3 Regression] DWARF information for function static variable is missing after unrelated code addition

[hubicka at ucw dot cz]

------- Comment #3 from hubicka at ucw dot cz  2006-12-22 00:54 -------
Subject: Re:  [4.2/4.3 Regression] DWARF information for function static
variable is missing after unrelated code addition

Hi,
Even if all frontends can do unit-at-a-time, non-unit-at-a-time is,
sadly, still essential for Java.  For Java it is common to do link-time
optimizations and our memory consumption with unit-at-a-time is too
large for this.  So fixing it is desirable.  Thank you for looking into
this!


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29614

[Bug debug/29614] [4.2/4.3 Regression] DWARF information for function static variable is missing after unrelated code addition

[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=29614

[Bug debug/29614] [4.2/4.3 Regression] DWARF information for function static variable is missing after unrelated code addition

[patchapp at dberlin dot org]

------- Comment #4 from patchapp at dberlin dot org  2007-02-20 21:40 -------
Subject: Bug number PR debug/29614

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/2007-02/msg01728.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29614

[Bug debug/29614] [4.2/4.3 Regression] DWARF information for function static variable is missing after unrelated code addition

[sje at gcc dot gnu dot org]

------- Comment #5 from sje at gcc dot gnu dot org  2007-02-24 00:11 -------
Subject: Bug 29614

Author: sje
Date: Sat Feb 24 00:11:39 2007
New Revision: 122277

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122277
Log:
        PR debug/29614
        * varpool.c (varpool_assemble_pending_decls):  Set
        varpool_last_needed_node to null.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/varpool.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29614

[Bug debug/29614] [4.2 Regression] DWARF information for function static variable is missing after unrelated code addition

[sje at gcc dot gnu dot org]

------- Comment #6 from sje at gcc dot gnu dot org  2007-03-05 23:52 -------
Subject: Bug 29614

Author: sje
Date: Mon Mar  5 23:52:09 2007
New Revision: 122583

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122583
Log:
        Backported from mainline
        PR debug/29614
        * cgraph.h (cgraph_varpool_last_needed_node): Make global.
        * cgraph.c (cgraph_varpool_last_needed_node): Ditto.
        * cgraphunit.c (cgraph_varpool_assemble_pending_decls):
        Set cgraph_varpool_last_needed_node to NULL.

Modified:
    branches/gcc-4_2-branch/gcc/ChangeLog
    branches/gcc-4_2-branch/gcc/cgraph.c
    branches/gcc-4_2-branch/gcc/cgraph.h
    branches/gcc-4_2-branch/gcc/cgraphunit.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29614

[Bug debug/29614] [4.2 Regression] DWARF information for function static variable is missing after unrelated code addition

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2007-03-05 23:56 -------
Fixed.


-- 

pinskia at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29614