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* [Bug debug/13365] New: Missing DWARF line info for empty function
@ 2003-12-09  4:32 gcc-bugzilla at gcc dot gnu dot org
  2003-12-09  5:22 ` [Bug debug/13365] [3.3/3.4 Regression] " pinskia at gcc dot gnu dot org
                   ` (8 more replies)
  0 siblings, 9 replies; 10+ messages in thread
From: gcc-bugzilla at gcc dot gnu dot org @ 2003-12-09  4:32 UTC (permalink / raw)
  To: gcc-bugs


Current CVS gcc generates DWARF line number information that is incomplete, a regression
from earlier gcc versions, such as the native RedHat 9 gcc.

Environment:
System: Linux fred.ninemoons.com 2.4.20-20.9 #1 Mon Aug 18 11:27:43 EDT 2003 i686 athlon i386 GNU/Linux
Architecture: i686

host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: /src/sourceware/gcc/gcc/configure -v --prefix=/usr/local/sourceware --enable-languages=c,c++ : (reconfigured) /src/sourceware/gcc/gcc/configure -v --prefix=/usr/local/sourceware --enable-languages=c

How-To-Repeat:

I decided to investigate the following failure in the gdb testsuite
funcargs.exp test, that has led to what I believe is a gcc bug in the
DWARF debug information generated by the latest compiler (3.4
20031207):

  FAIL: gdb.base/funcargs.exp: continue to call6k

The problem can reproduced using:

  void foo ()
  {
  }

  void bar ()
  {
    static int dummy = 0;
  }

  main ()
  {
    foo ();
    bar ();
  }

If I debug the above program compiled with the 20031207 gcc, gdb
prints it's breakpoint stop message differently for foo than for bar:

  $ /usr/local/sourceware/bin/gcc -g -o x x.c
  $ gdb -q x
  (gdb) br foo
  Breakpoint 1 at 0x8048327: file x.c, line 2.
  (gdb) bar bar
  Undefined command: "bar".  Try "help".
  (gdb) br bar
  Breakpoint 2 at 0x804832c: file x.c, line 8.
  (gdb) run
  Starting program: /tmp/x 
  
  Breakpoint 1, 0x08048327 in foo () at x.c:2
  2       {
  (gdb) c
  Continuing.
  
  Breakpoint 2, bar () at x.c:8
  8       }

However debugging the program when compiled with the native RedHat 9 gcc
produces different, and correct, results:

  $ /usr/bin/gcc -g -o x x.c
  $ gdb -q x
  (gdb) br foo
  Breakpoint 1 at 0x80482f7: file x.c, line 3.
  (gdb) br bar
  Breakpoint 2 at 0x80482fc: file x.c, line 8.
  (gdb) run
  Starting program: /tmp/x 
  
  Breakpoint 1, foo () at x.c:3
  3       }
  (gdb) c
  Continuing.
  
  Breakpoint 2, bar () at x.c:8
  8       }
  (gdb) 

If you dump the debug line info for the 20031207 gcc compiled executable
using "readelf --debug-dump=line x" you get:

 Line Number Statements:
  Extended opcode 2: set Address to 0x8048324
  Special opcode 6: advance Address by 0 to 0x8048324 and Line by 1 to 2
  Special opcode 79: advance Address by 5 to 0x8048329 and Line by 4 to 6
  Special opcode 49: advance Address by 3 to 0x804832c and Line by 2 to 8
  Special opcode 36: advance Address by 2 to 0x804832e and Line by 3 to 11
  Advance PC by constant 17 to 0x804833f
  Special opcode 160: advance Address by 11 to 0x804834a and Line by 1 to 12
  Special opcode 76: advance Address by 5 to 0x804834f and Line by 1 to 13
  Special opcode 76: advance Address by 5 to 0x8048354 and Line by 1 to 14
  Advance PC by 2 to 8048356
  Extended opcode 1: End of Sequence

Dumping the debug line info for the native RedHat 9 gcc compiled executable
produces:

 Line Number Statements:
  Extended opcode 2: set Address to 0x80482f4
  Special opcode 6: advance Address by 0 to 0x80482f4 and Line by 1 to 2
  Special opcode 48: advance Address by 3 to 0x80482f7 and Line by 1 to 3  <=== NOTE
  Special opcode 36: advance Address by 2 to 0x80482f9 and Line by 3 to 6
  Special opcode 49: advance Address by 3 to 0x80482fc and Line by 2 to 8
  Special opcode 36: advance Address by 2 to 0x80482fe and Line by 3 to 11
  Special opcode 230: advance Address by 16 to 0x804830e and Line by 1 to 12
  Special opcode 76: advance Address by 5 to 0x8048313 and Line by 1 to 13
  Special opcode 76: advance Address by 5 to 0x8048318 and Line by 1 to 14
  Advance PC by 2 to 804831a
  Extended opcode 1: End of Sequence

Note that the 20031207 compiled debug info is missing the line number
info corresponding to "advance Address by 3 to 0x80482f7 and Line by 1
to 3" that is in the RedHat 9 executable.

For more in depth discussion of the gdb issues see the thread at:

  http://sources.redhat.com/ml/gdb-patches/2003-12/msg00253.html

-Fred

-- 
           Summary: Missing DWARF line info for empty function
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: fnf at ninemoons dot com
                CC: gcc-bugs at gcc dot gnu dot org
 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=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
@ 2003-12-09  5:22 ` pinskia at gcc dot gnu dot org
  2003-12-09  5:24 ` pinskia at gcc dot gnu dot org
                   ` (7 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2003-12-09  5:22 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-12-09 05:22 -------
Confirmed, a regression from 3.2.3.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |wrong-code
   Last reconfirmed|0000-00-00 00:00:00         |2003-12-09 05:22:02
               date|                            |
            Summary|Missing DWARF line info for |[3.3/3.4 Regression] Missing
                   |empty function              |DWARF line info for empty
                   |                            |function
   Target Milestone|---                         |3.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
  2003-12-09  5:22 ` [Bug debug/13365] [3.3/3.4 Regression] " pinskia at gcc dot gnu dot org
@ 2003-12-09  5:24 ` pinskia at gcc dot gnu dot org
  2003-12-23 22:09 ` janis187 at us dot ibm dot com
                   ` (6 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2003-12-09  5:24 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-12-09 05:24 -------
Should note I also tested 3.3.1 where the problem is too.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
  2003-12-09  5:22 ` [Bug debug/13365] [3.3/3.4 Regression] " pinskia at gcc dot gnu dot org
  2003-12-09  5:24 ` pinskia at gcc dot gnu dot org
@ 2003-12-23 22:09 ` janis187 at us dot ibm dot com
  2004-01-10 15:53 ` pinskia at gcc dot gnu dot org
                   ` (5 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: janis187 at us dot ibm dot com @ 2003-12-23 22:09 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From janis187 at us dot ibm dot com  2003-12-23 20:00 -------
The regression in PR 13365 was introduced or exposed on mainline with
this patch:

Sat Feb 22 12:42:16 CET 2003  Jan Hubicka  <jh@suse.cz>

        * c-decl.c (c_expand_body_1): Fix.

and on the 3.3-branch with:

2003-06-12  Jakub Jelinek  <jakub@redhat.com>

        * c-decl.c (c_expand_body): Save input_filename and lineno,
        set it before tree inlining and restore before return.

The regression hunts took place on i686-pc-linux-gnu using the                 
submitter's test case compiled with -g.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at redhat dot com, jh
                   |                            |at suse dot cz


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
                   ` (2 preceding siblings ...)
  2003-12-23 22:09 ` janis187 at us dot ibm dot com
@ 2004-01-10 15:53 ` pinskia at gcc dot gnu dot org
  2004-01-10 16:23 ` pinskia at gcc dot gnu dot org
                   ` (4 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-01-10 15:53 UTC (permalink / raw)
  To: gcc-bugs



-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |minor
           Keywords|wrong-code                  |wrong-debug
   Target Milestone|3.3.3                       |3.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
                   ` (3 preceding siblings ...)
  2004-01-10 15:53 ` pinskia at gcc dot gnu dot org
@ 2004-01-10 16:23 ` pinskia at gcc dot gnu dot org
  2004-01-11  5:21 ` drow at gcc dot gnu dot org
                   ` (3 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-01-10 16:23 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-10 16:23 -------
Not worth fixing as line info for empty functions can be either place.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
                   ` (4 preceding siblings ...)
  2004-01-10 16:23 ` pinskia at gcc dot gnu dot org
@ 2004-01-11  5:21 ` drow at gcc dot gnu dot org
  2004-01-25  3:09 ` [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF2 " pinskia at gcc dot gnu dot org
                   ` (2 subsequent siblings)
  8 siblings, 0 replies; 10+ messages in thread
From: drow at gcc dot gnu dot org @ 2004-01-11  5:21 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From drow at gcc dot gnu dot org  2004-01-11 05:21 -------
That's got nothing to do with it.  The issue is not which line the second
line note specifies but that there be a second line note marking the end
of the prologue.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|WONTFIX                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF2 line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
                   ` (5 preceding siblings ...)
  2004-01-11  5:21 ` drow at gcc dot gnu dot org
@ 2004-01-25  3:09 ` pinskia at gcc dot gnu dot org
  2004-01-27  5:55 ` [Bug debug/13365] [3.3 " pinskia at gcc dot gnu dot org
  2004-01-29  5:02 ` gdr at gcc dot gnu dot org
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-01-25  3:09 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-25 03:09 -------
Fixed in 3.5 at least:
 Line Number Statements:
  Extended opcode 2: set Address to 0x8048324
  Special opcode 6: advance Address by 0 to 0x8048324 and Line by 1 to 2
  Special opcode 47: advance Address by 3 to 0x8048327 and Line by 0 to 2  <-- note
  Special opcode 37: advance Address by 2 to 0x8048329 and Line by 4 to 6
  Special opcode 49: advance Address by 3 to 0x804832c and Line by 2 to 8
  Special opcode 36: advance Address by 2 to 0x804832e and Line by 3 to 11
  Advance PC by constant 17 to 0x804833f
  Special opcode 160: advance Address by 11 to 0x804834a and Line by 1 to 12
  Special opcode 76: advance Address by 5 to 0x804834f and Line by 1 to 13
  Special opcode 76: advance Address by 5 to 0x8048354 and Line by 1 to 14
  Advance PC by 2 to 8048356
  Extended opcode 1: End of Sequence

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[3.3/3.4/3.5 Regression]    |[3.3/3.4 Regression] Missing
                   |Missing DWARF line info for |DWARF2 line info for empty
                   |empty function              |function


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3 Regression] Missing DWARF2 line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
                   ` (6 preceding siblings ...)
  2004-01-25  3:09 ` [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF2 " pinskia at gcc dot gnu dot org
@ 2004-01-27  5:55 ` pinskia at gcc dot gnu dot org
  2004-01-29  5:02 ` gdr at gcc dot gnu dot org
  8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-01-27  5:55 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-27 05:55 -------
This also works in 3.4 now too.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |NEW
      Known to work|3.5.0                       |3.2.3 3.5.0 3.4.0
            Summary|[3.3/3.4 Regression] Missing|[3.3 Regression] Missing
                   |DWARF2 line info for empty  |DWARF2 line info for empty
                   |function                    |function
   Target Milestone|3.4.0                       |3.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [Bug debug/13365] [3.3 Regression] Missing DWARF2 line info for empty function
  2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
                   ` (7 preceding siblings ...)
  2004-01-27  5:55 ` [Bug debug/13365] [3.3 " pinskia at gcc dot gnu dot org
@ 2004-01-29  5:02 ` gdr at gcc dot gnu dot org
  8 siblings, 0 replies; 10+ messages in thread
From: gdr at gcc dot gnu dot org @ 2004-01-29  5:02 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From gdr at gcc dot gnu dot org  2004-01-29 05:02 -------
Unlikely to be fixed in 3.3.x

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13365


^ permalink raw reply	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2004-01-29  5:02 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-12-09  4:32 [Bug debug/13365] New: Missing DWARF line info for empty function gcc-bugzilla at gcc dot gnu dot org
2003-12-09  5:22 ` [Bug debug/13365] [3.3/3.4 Regression] " pinskia at gcc dot gnu dot org
2003-12-09  5:24 ` pinskia at gcc dot gnu dot org
2003-12-23 22:09 ` janis187 at us dot ibm dot com
2004-01-10 15:53 ` pinskia at gcc dot gnu dot org
2004-01-10 16:23 ` pinskia at gcc dot gnu dot org
2004-01-11  5:21 ` drow at gcc dot gnu dot org
2004-01-25  3:09 ` [Bug debug/13365] [3.3/3.4 Regression] Missing DWARF2 " pinskia at gcc dot gnu dot org
2004-01-27  5:55 ` [Bug debug/13365] [3.3 " pinskia at gcc dot gnu dot org
2004-01-29  5:02 ` gdr at gcc dot gnu dot org

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