On Thu, May 5, 2011 at 2:20 AM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hi!
>
> My typed DWARF stack changes apparently broke ia64-hpux and H.J.'s out of
> tree x32 target. There are several issues:
> 1) for SUBREG mem_loc_descriptor's 3rd argument was wrong, found by code
> inspection
> 2) CONST/SYMBOL_REF/LABEL_REF when in MEM addresses on
> POINTERS_EXTEND_UNSIGNED
> targets are often Pmode, which is unfortunately larger than DWARF2_ADDR_SIZE
> and my conditional would just return NULL in that case instead of
> emitting DW_OP_addr.
> 3) and, when mem_loc_descriptor is called from unwind code, Pmodes larger
> than DWARF2_ADDR_SIZE would result in the new DW_OP_GNU_*_type etc. ops
> which are not allowed in .eh_frame/.debug_frame
> The following patch ought to fix that, bootstrapped/regtested on
> x86_64-linux and i686-linux and Steve tested it on ia64-hpux and H.J. on his
> port. Ok for trunk?
>
> 2011-05-05 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/48853
> * dwarf2out.c (mem_loc_descriptor) <case SUBREG>: Pass mem_mode
> instead of mode as 3rd argument to recursive call.
> (mem_loc_descriptor) <case REG>: If POINTERS_EXTEND_UNSIGNED, don't
> emit DW_OP_GNU_regval_type if mode is Pmode and mem_mode is not
> VOIDmode.
> (mem_loc_descriptor) <case SYMBOL_REF>: If POINTERS_EXTEND_UNSIGNED,
> don't give up if mode is Pmode and mem_mode is not VOIDmode.
> (mem_loc_descriptor) <case CONST_INT>: If POINTERS_EXTEND_UNSIGNED,
> use int_loc_descriptor if mode is Pmode and mem_mode is not VOIDmode.
>
Another problem. This patch
http://gcc.gnu.org/ml/gcc-patches/2011-03/msg01730.html
has
@@ -14562,7 +15110,10 @@ loc_descriptor (rtx rtl, enum machine_mo
up an entire register. For now, just assume that it is
legitimate to make the Dwarf info refer to the whole register which
contains the given subreg. */
- loc_result = loc_descriptor (SUBREG_REG (rtl), mode, initialized);
+ if (REG_P (SUBREG_REG (rtl)) && subreg_lowpart_p (rtl))
+ loc_result = loc_descriptor (SUBREG_REG (rtl), mode, initialized);
+ else
+ goto do_default;
break;
case REG:
It doesn't work with Pmode != ptr_mode. I got
Breakpoint 5, loc_descriptor (rtl=0x7ffff0acc900, mode=SImode,
initialized=VAR_INIT_STATUS_INITIALIZED)
at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:15027
15027 if ((REG_P (SUBREG_REG (rtl))
(gdb) bt
#0 loc_descriptor (rtl=0x7ffff0acc900, mode=SImode,
initialized=VAR_INIT_STATUS_INITIALIZED)
at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:15027
#1 0x00000000006dae2a in loc_descriptor (rtl=0x7ffff0a6c660, mode=SImode,
initialized=VAR_INIT_STATUS_INITIALIZED)
at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:15071
#2 0x00000000006dbc69 in dw_loc_list_1 (loc=0x7ffff0a87320,
varloc=0x7ffff0a6c660, want_address=2,
initialized=VAR_INIT_STATUS_INITIALIZED)
at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:15346
#3 0x00000000006dc5b2 in dw_loc_list (loc_list=0x7ffff0a6c800,
decl=0x7ffff0a87320, want_address=2)
at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:15602
#4 0x00000000006dd920 in loc_list_from_tree (loc=0x7ffff0a87320,
want_address=2) at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:15990
#5 0x00000000006e3d81 in add_location_or_const_value_attribute (
die=0x7ffff0acd640, decl=0x7ffff0a87320, cache_p=0 '\000',
attr=DW_AT_location)
at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:17500
#6 0x00000000006eae13 in gen_formal_parameter_die (node=0x7ffff0a87320,
origin=0x7ffff0b71d48, emit_name_p=1 '\001', context_die=0x7ffff0acd5a0)
at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:19244
#7 0x00000000006f6432 in gen_decl_die (decl=0x7ffff0a87320, origin=0x0,
---Type <return> to continue, or q <return> to quit---q
contextQuit
(gdb) call debug_rtx (rtl)
(subreg:SI (symbol_ref:DI ("a") [flags 0x2] <var_decl 0x7ffff0a87000 a>) 0)
(gdb) f 1
#1 0x00000000006dae2a in loc_descriptor (rtl=0x7ffff0a6c660, mode=SImode,
initialized=VAR_INIT_STATUS_INITIALIZED)
at /export/gnu/import/git/gcc-x32/gcc/dwarf2out.c:15071
15071 loc_result = loc_descriptor (loc, mode, initialized);
(gdb) call debug_rtx (rtl)
(var_location xxxxx (subreg:SI (symbol_ref:DI ("a") [flags 0x2]
<var_decl 0x7ffff0a87000 a>) 0))
This patch restores the old behavior for Pmode. OK for trunk if there
are no regressions?
Thanks.
--
H.J.
2011-05-11 H.J. Lu <hongjiu...@intel.com>
PR debug/48853
* dwarf2out.c (loc_descriptor) <case SUBREG>: If
POINTERS_EXTEND_UNSIGNED is defined, don't give up if mode of
SUBREG is Pmode.
2011-05-11 H.J. Lu <hongjiu...@intel.com>
PR debug/48853
* dwarf2out.c (loc_descriptor) <case SUBREG>: If
POINTERS_EXTEND_UNSIGNED is defined, don't give up if mode of
SUBREG is Pmode.
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index b85a55e..03d12de 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -15024,7 +15024,12 @@ loc_descriptor (rtx rtl, enum machine_mode mode,
up an entire register. For now, just assume that it is
legitimate to make the Dwarf info refer to the whole register which
contains the given subreg. */
- if (REG_P (SUBREG_REG (rtl)) && subreg_lowpart_p (rtl))
+ if ((REG_P (SUBREG_REG (rtl))
+#ifdef POINTERS_EXTEND_UNSIGNED
+ || GET_MODE (SUBREG_REG (rtl)) == Pmode
+#endif
+ )
+ && subreg_lowpart_p (rtl))
loc_result = loc_descriptor (SUBREG_REG (rtl), mode, initialized);
else
goto do_default;
