Re: [RFA] mips, eabi64, addr_bit == 32

Mark Kettenis
2006-06-17T23:15:06Z

> Date: Wed, 31 May 2006 16:25:36 -0700
> From: Michael Snyder <msnyder@redhat.com>
>
> Disagreement between gcc and gdb about the size of an addr
> causes numerous dwarf2-related complaints of the form:
>
> (gdb) advance foo^M
> foo (a=dwarf2_read_address: Corrupted DWARF expression.^M
> ) at
> /opt/redhat/gnupro-06r1-1/sources/tools/cross/gdb/testsuite/gdb.base/advan\ce.c:6^M
> 6 int b = a + 10;^M
> (gdb) FAIL: gdb.base/advance.exp: advance function called as param

Is this patch still on the table? It looks highly suspicious to me.
I mean, you have 64-bit pointers, but 32-bit addresses?

Shouldn't we just fix GCC to emit the correct debug info?

> 2006-05-31 Michael Snyder <msnyder@redhat.com>
>
> * mips-tdep.c (mips_gdbarch_init): EABI64, addr_bit is 32.
> (mips_write_pc): Difference between addr_bit and ptr_bit
> requires sign_extension when setting $pc.
>
> Index: mips-tdep.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/mips-tdep.c,v
> retrieving revision 1.393
> diff -p -r1.393 mips-tdep.c
> *** mips-tdep.c 31 May 2006 23:15:50 -0000 1.393
> --- mips-tdep.c 31 May 2006 23:18:47 -0000
> *************** mips_unwind_dummy_id (struct gdbarch *gd
> *** 838,843 ****
> --- 838,847 ----
> static void
> mips_write_pc (CORE_ADDR pc, ptid_t ptid)
> {
> + /* If addr_bit is 32, force sign extension. */
> + if (gdbarch_addr_bit (current_gdbarch) == 32)
> + if ((pc & 0xffffffff80000000LL) == 0x80000000)
> + pc |= 0xffffffff00000000LL;
> write_register_pid (mips_regnum (current_gdbarch)->pc, pc, ptid);
> }
>
> *************** mips_gdbarch_init (struct gdbarch_info i
> *** 4976,4981 ****
> --- 4980,4986 ----
> tdep->default_mask_address_p = 0;
> set_gdbarch_long_bit (gdbarch, 64);
> set_gdbarch_ptr_bit (gdbarch, 64);
> + set_gdbarch_addr_bit (gdbarch, 32);
> set_gdbarch_long_long_bit (gdbarch, 64);
> break;
> case MIPS_ABI_N32: