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

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> 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: