[Bug debug/21946] New: Invalid DWARF2 debug info emitted

[Bug debug/21946] New: Invalid DWARF2 debug info emitted

[jakub at gcc dot gnu dot org]

On ppc32:
/* { dg-options "-m32 -O2 -g" } */
extern int m;
struct A { unsigned char a; };
struct B { void *b; };
extern struct B *fn (int x);
struct C { struct C *c; };
static unsigned char *d;
typedef int (*T) (struct C *, void *);
struct C *foo (struct C *, T, void *);
int fx (struct C *, void *);

static struct C *
bar (struct C *x, unsigned char y, unsigned char z)
{
  unsigned char v[2] = { y, z };
  return foo (x, fx, v);
}

struct C *
baz (struct A *x, long long int y)
{
  struct B *b;
  struct C *c;
  long long int z;

  if (!(m == 4 || m == 2))
    return 0;
  z = x->a;
  b = fn (z);
  if (!b)
    return 0;
  c = (struct C *) b->b;
  if (!c)
    return 0;
  if (m == 2 && z >= 240)
    z -= 240;
  else if (d)
    z = d[z];
  if (z == 255)
    return 0;
  return bar (c->c, z, y);
}

emits:
emits in one range for the y variable (DImode, i.e. 2 hard registers):
        .4byte  .LVL0-.Ltext0    # Location list begin address (*.LLST2)
        .4byte  .LVL2-.Ltext0    # Location list end address (*.LLST2)
        .2byte  0x6      # Location expression size
        .byte   0x55     # DW_OP_reg5
        .byte   0x93     # DW_OP_piece
        .byte   0x4      # uleb128 0x4
        .byte   0x56     # DW_OP_reg6
        .byte   0x93     # DW_OP_piece
        .byte   0x4      # uleb128 0x4
        .4byte  .LVL2-.Ltext0    # Location list begin address (*.LLST2)
        .4byte  .LVL3-.Ltext0    # Location list end address (*.LLST2)
        .2byte  0xb      # Location expression size
        .byte   0x55     # DW_OP_reg5
        .byte   0x93     # DW_OP_piece
        .byte   0x4      # uleb128 0x4
        .byte   0x56     # DW_OP_reg6
        .byte   0x93     # DW_OP_piece
        .byte   0x4      # uleb128 0x4
        .byte   0x93     # DW_OP_piece
        .byte   0x8      # uleb128 0x8
        .byte   0x56     # DW_OP_reg6
        .byte   0x93     # DW_OP_piece
        .byte   0x4      # uleb128 0x4
...

Similar problems occur even on little-endian targets, although less often:
           0xffffffff8014ebb0..0xffffffff8014ebc2 [   0] fbreg 160
                                                  [   3] piece 4
                                                  [   5] fbreg 164
                                                  [   8] piece 4
           0xffffffff8014ebc2..0xffffffff8014ebc4 [   0] fbreg 160
           0xffffffff8014ebc4..0xffffffff8014ebd6 [   0] fbreg 160
                                                  [   3] piece 8        <-- BAD
                                                  [   5] fbreg 164
                                                  [   8] piece 4
(64-bit variable).

Not a regression, as -fvar-tracking is new in GCC 4.0, though one might say
that before we at least were not generating invalid debug info.

-- 
           Summary: Invalid DWARF2 debug info emitted
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: debug
        AssignedTo: jakub at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: ppc-linux, x86_64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21946

[Bug debug/21946] Invalid DWARF2 debug info emitted

[jakub at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2005-
                   |                            |06/msg00312.html
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-06-07 08:41:52
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21946

[Bug debug/21946] Invalid DWARF2 debug info emitted

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-06-07 10:17 -------
Subject: Bug 21946

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	jakub@gcc.gnu.org	2005-06-07 10:17:36

Modified files:
	gcc            : ChangeLog dwarf2out.c var-tracking.c 
	                 Makefile.in 

Log message:
	PR debug/21946
	* dwarf2out.c (add_loc_descr_op_piece): New function.
	(multiple_reg_loc_descriptor, concat_loc_descriptor,
	loc_descriptor): Use it.
	* var-tracking.c: Include regs.h and expr.h.
	(emit_note_insn_var_location): Skip over pieces where offset
	is smaller than previous offset plus previous piece mode size.
	Optimize adjacent hard registers or memory locations.
	* Makefile.in (var-tracking.o): Depend on $(REGS_H) and $(EXPR_H).

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.9065&r2=2.9066
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/dwarf2out.c.diff?cvsroot=gcc&r1=1.597&r2=1.598
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/var-tracking.c.diff?cvsroot=gcc&r1=2.28&r2=2.29
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/Makefile.in.diff?cvsroot=gcc&r1=1.1498&r2=1.1499



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21946

[Bug debug/21946] [4.0 Regression] Invalid DWARF2 debug info emitted

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-debug
      Known to work|                            |4.1.0
   Last reconfirmed|2005-06-07 08:41:52         |2005-06-07 15:20:16
               date|                            |
            Summary|Invalid DWARF2 debug info   |[4.0 Regression] Invalid
                   |emitted                     |DWARF2 debug info emitted
   Target Milestone|---                         |4.0.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21946

[Bug debug/21946] [4.0 Regression] Invalid DWARF2 debug info emitted

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-06-08 07:48 -------
Subject: Bug 21946

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	ebotcazou@gcc.gnu.org	2005-06-08 07:48:28

Modified files:
	gcc            : ChangeLog dwarf2out.c 

Log message:
	PR debug/21946
	* dwarf2out.c (add_loc_descr_op_piece): Move to the
	DWARF2_DEBUGGING_INFO section.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.9086&r2=2.9087
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/dwarf2out.c.diff?cvsroot=gcc&r1=1.599&r2=1.600



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21946

[Bug debug/21946] [4.0 Regression] Invalid DWARF2 debug info emitted

[mmitchel at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.0.1                       |4.0.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21946

[Bug debug/21946] [4.0 Regression] Invalid DWARF2 debug info emitted

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-07-09 08:44 -------
Subject: Bug 21946

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-4_0-branch
Changes by:	jakub@gcc.gnu.org	2005-07-09 08:44:27

Modified files:
	gcc            : ChangeLog Makefile.in dwarf2out.c 
	                 var-tracking.c 

Log message:
	Backport from the mainline:
	2005-06-08  Eric Botcazou  <ebotcazou@libertysurf.fr>
	PR debug/21946
	* dwarf2out.c (add_loc_descr_op_piece): Move to the
	DWARF2_DEBUGGING_INFO section.
	
	2005-06-07  Jakub Jelinek  <jakub@redhat.com>
	PR debug/21946
	* dwarf2out.c (add_loc_descr_op_piece): New function.
	(multiple_reg_loc_descriptor, concat_loc_descriptor,
	loc_descriptor): Use it.
	* var-tracking.c: Include regs.h and expr.h.
	(emit_note_insn_var_location): Skip over pieces where offset
	is smaller than previous offset plus previous piece mode size.
	Optimize adjacent hard registers or memory locations.
	* Makefile.in (var-tracking.o): Depend on $(REGS_H) and $(EXPR_H).

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=2.7592.2.306&r2=2.7592.2.307
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/Makefile.in.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.1447.2.1&r2=1.1447.2.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/dwarf2out.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.570.2.8&r2=1.570.2.9
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/var-tracking.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=2.26&r2=2.26.10.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21946

[Bug debug/21946] [4.0 Regression] Invalid DWARF2 debug info emitted

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-09 15:13 -------
Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21946