[Bug bootstrap/41405] [4.5 Regression] Bootstrap fails at revision 151873 on *-apple-darwin9

["dominiq at lps dot ens dot fr" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #13 from dominiq at lps dot ens dot fr  2009-09-20 15:24 -------
The culprit is indeed r151815. Reverting the change after having updated to
r151893 on i686-apple-darwin9 ( r151895 on powerpc-apple-darwin9) allows a
successful bootstrap (currently building the libs on powerpc).

In http://gcc.gnu.org/ml/gcc-patches/2009-09/msg00220.html the patch is
motivated by:

> I think the important question is whether older debuggers would be able
> to deal gracefully with these location entries or constant values.  I
> understand they're supposed to, and I have no evidence that GDB isn't, so
> I offer this patch to revert the last-minute addition of tests for
> dwarf_version >= 4 in the VTA merge patch.
> 
> Should I check it in so that we can get a better idea of what, if
> anything, breaks?

Apparently the changes affect more than GDB. So now that you have "get a better
idea of what, if anything, breaks" it seems appropriate to revert them.

> Yes, probably the apple tools barf on the new dwarf opcodes.  Please report the
> issue to them.  

As far as I understand the problem, I do not see why tools not designed to
accept "dwarf_version 4" can be blamed for that (it would be like blaming the
CD player in my car for not reading MP3 CDs).

> A GCC side fix would be to add an option to restrict dwarf to dwarf2 and turn that option on by 
> default for darwin.

What is the difference with reverting the patch?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41405