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
