------- Comment #2 from danglin at gcc dot gnu dot org 2008-11-18 02:31 -------
The hppa gas target currently defines DWARF2_LINE_MIN_INSN_LENGTH to 4 in
tc-hppa.h. I can fix this failure by changing DWARF2_LINE_MIN_INSN_LENGTH
to 1. However, the failure appears to be caused by an inconsistency in
the handling of DW_CFA_advance_loc1, DW_CFA_advance_loc2 and
DW_CFA_advance_loc4
in dw2gencfi.c and unwind-dw2.c.
In dw2gencfi.c, we have:
addressT delta = S_GET_VALUE (to) - S_GET_VALUE (from);
addressT scaled = delta / DWARF2_LINE_MIN_INSN_LENGTH;
if (scaled <= 0x3F)
out_one (DW_CFA_advance_loc + scaled);
else if (delta <= 0xFF)
{
out_one (DW_CFA_advance_loc1);
out_one (delta);
}
else if (delta <= 0xFFFF)
{
out_one (DW_CFA_advance_loc2);
out_two (delta);
}
else
{
out_one (DW_CFA_advance_loc4);
out_four (delta);
}
In unwind-dw2.c, we have:
case DW_CFA_advance_loc1:
fs->pc += read_1u (insn_ptr) * fs->code_align;
insn_ptr += 1;
break;
case DW_CFA_advance_loc2:
fs->pc += read_2u (insn_ptr) * fs->code_align;
insn_ptr += 2;
break;
case DW_CFA_advance_loc4:
fs->pc += read_4u (insn_ptr) * fs->code_align;
insn_ptr += 4;
break;
The code in binutils/dwarf.c also scales the file values by the code
alignment factor. So two against one says the dw2gencfi.c code is wrong.
--
danglin at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rth at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37610
