Re: [RFA] PowerPC VLE port

["Maciej W. Rozycki" <macro at codesourcery dot com>]

On Sat, 13 Aug 2011, Alan Modra wrote:

> -/* This bit is reserved by BFD for processor specific stuff.  Name
> -   it properly so that we can easily stay consistent elsewhere.  */
> -#define SEC_PPC_VLE		SEC_TIC54X_BLOCK
> 
> Please revert this accidental commit now rather than waiting until the
> whole patch is approved.

 Not accidental at all.  This bit is used in bfd/coffcode.h like this:

#ifdef STYP_BLOCK
  if (sec_flags & SEC_TIC54X_BLOCK)
    styp_flags |= STYP_BLOCK;
#endif

that is potentially for any target defining STYP_BLOCK.

 I can see that STYP_BLOCK is only defined by include/coff/ti.h, so the 
overloading of this flag like this should be safe after all, but I find 
this confusing and I think that while the macro can indeed use the bit 
occupied by SEC_TIC54X_BLOCK, a couple of adjustments should be made:

1. STYP_BLOCK (and consequently STYP_CLINK) should be renamed 
   STYP_TIC54X_BLOCK (STYP_TIC54X_CLINK) to indicate they are
   target-specific.

2. The definition of SEC_TIC54X_BLOCK (and SEC_TIC54X_CLINK) in 
   bfd/section.c replaced with SEC_BACKEND_1 (and SEC_BACKEND_2) or 
   suchlike, to indicate these two bits are backend-specific, and the two 
   former macros only defined by the include/coff/ti.h, in terms of the 
   two latters (respectively).

3. Likewise SEC_PPC_VLE (and SEC_MEP_VLIW) redefined in terms of 
   SEC_BACKEND_1.

 Do you agree?

> > +.  {*  Indicate that the section has the VLE bit set. *}
> > +.#define SEC_PPC_VLE 0x80000000
> > +.
> 
> Where is this used?  If needed, I'd rather see one of the sec_flg[0-6]
> bits used instead for backend specific flags.

 OK, so should we keep this flag or not after all, hmm?  It looks to me 
like the removal above you've objected is good either way. :)

  Maciej