Re: [commit/multiarch/hpux] set addr_bits_remove gdbarch method

[Joel Brobecker <brobecker@gnat.com>]

[Coming back to an old thread. Was it that long ago already? Sigh...]

On Wed, Aug 13, 2003 at 02:39:55PM -0400, Andrew Cagney wrote:
> Yep: Consider merging SMASH_TEXT_ADDRESS with ADDR_BITS_REMOVE
> http://sources.redhat.com/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gdb&pr=333
> 
> Any one got a preference over which one goes?  Otherwize, Joel, with 
> HP/UX cleaned up, it should either way be pretty obvious.

I looked a bit at the code, and I have a small preference of
ADDR_BITS_REMOVE over SMASH_TEXT_ADDRESS. In addition, the only
2 targets that set smash_text_address also define addr_bits_remove
(hppa-tdep.c and arm-tdep.c).  So it looked like there would be an easy
transition:

  - s/SMASH_TEXT_ADDRESS/ADDR_BITS_REMOVE/g
    This should be a noop if we assume:
        SMASH_TEXT_ADDRESS <=> ADDR_BITS_REMOVE

  - Remove the two calls to gdb_arch_set_smash_text_address
  - Delete the SMASH_TEXT_ADDRESS gdbarch method

Unfortunately, It doesn't look like these two methods are that
identical, at least in the case of arm:

    static CORE_ADDR
    arm_addr_bits_remove (CORE_ADDR val)
    {
      if (arm_apcs_32)
        return (val & (arm_pc_is_thumb (val) ? 0xfffffffe : 0xfffffffc));
      else
        return (val & 0x03fffffc);
    }
    
    /* When reading symbols, we need to zap the low bit of the address,
       which may be set to 1 for Thumb functions.  */
    static CORE_ADDR
    arm_smash_text_address (CORE_ADDR val)
    {
      return val & ~1;
    }

SMASH_TEXT_ADDRESS is used in coffread, dbxread, dwarfread, elfread,
and somread.

ADDR_BITS_REMOVE is used in arm*.c, buildsym, infrun, monitor, printcmd,
regcache, remote-mips, values.c (I have deliberately excluded mips-tdep,
remote-mips, s390-tdep, and sh64-tdep since these can not be covered
while the arm gdbarch is in effect).

Looks like the merge is not going to be that obvious... We need to see
if we can merge arm_addr_bits_remove and arm_smash_text_address first...

-- 
Joel