Re: [PATCH] Proper _to_regnum for DWARF on Cygwin

[Mark Kettenis <kettenis@chello.nl>]

   Date: 19 Apr 2004 08:50:59 +0200
   From: Eli Zaretskii <eliz@elta.co.il>

   > Date: Sun, 18 Apr 2004 20:38:38 +0200 (CEST)
   > From: Mark Kettenis <kettenis@chello.nl>
   > 
   > +  /* We typically use DWARF-in-COFF with the dbx register numbering.  */
   > +  set_gdbarch_dwarf_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum);
   > +  set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum);
   >  }

   Mark, doesn't this code above from i386_coff_init_abi contradict the
   code further down (and the register mapping used by GCC), viz:

   > +  /* Use the SVR4 register numbering scheme for DWARF and DWARF 2.  */
   > +  set_gdbarch_dwarf_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum);
   > +  set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum);

   ?  For DJGPP, at least, DWARF2-in-COFF uses i386_svr4_reg_to_regnum
   register mapping, not i386_dbx_reg_to_regnum.  Am I missing something
   here?

Hmm.  I very much agree with what Brian wrote in his follow-up
messages.  I think DJGPP is doing the right thing using the SVR4
scheme for DWARF2 while staying backwards compatible for stabs.  I'd
advise him to do the same for cygwin.  If i386_coff_init_abi will be
gone, the comments aren't contradictiory anymore.

   > +  /* NOTE: kettenis/20040418: GCC does have two possible register
   > +     numbering schemes on the i386: dbx and SVR4.  These schemes
   > +     differ in how they number %ebp, %esp, %eflags, and the
   > +     floating-point registers, and are implemented by the attays
								^^^^^^
   A typo.

I though I'd fixed that one :-(.