[fpc-devel] x86_64 stabs info - patch (sort of)

[Jonas Maebe]

On 12 Oct 2010, at 21:55, Willibald Krenn wrote:

> Am 12.10.2010 20:33, schrieb Jonas Maebe:
>>> dwarf2 debug information seems to be broken too.
>> 
>> Keep this in mind: http://bugs.freepascal.org/view.php?id=15692
> 
> I don't know exactly what to conclude from this discussion.

Try using the -WB0040000 command line option.

> Are 32 bit pointers enough for WinPE? Then stabs would be fine anyways.

The problem is that GDB (at least in the past) zero-extends all offsets in the stabs debug information. That means that a local variable at location ebp-16 is interpreted as being at location ebp+4294967280. There are probably more such small problems, because Stabs was never designed nor implemented to be used for 64 bit platforms within the GNU tool chain.

>> You may also want to try with the external linker (-Xe).
> 
> Hmm, -Xe does not seem to work on my system.

What does "not work" mean?

> So, stabs remains the only thing that is working. (Even if it has limitations it is better than 0.)

I'm not opposed to committing that change, it's just that Stabs is a dead end and since no compiler I know of uses it for generating 64 bit debug information (other than a few older Mac OS X compilers, but Mac OS X uses its own fork of GDB), it's probably also very badly tested within GDB itself.


Jonas
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