On 29/04/2026 23:45, Pierre Muller via fpc-devel wrote:
It also breaks this for FpDebug, which was able to show them. (btw, gdb
can too)
Though, it is still correct.... (more or less).
I agree, we do need DWARF that works with GDB...
GDB is generating an assertion error when trying to dispaly the value
of these constants.
Yes, if language is Pascal.
From what I could find (and I am not very acquainted with the gdb
source, so its little), if GDB does not see an address, it checks that
the bitoffset is 0. => but it that check asserts that a bit address must
be explicitly given.
Which leads to an interesting question
- Why wasn't it fixed?
It now works for classes, but is left broken for advanced records (see
example at the end)....
I do not understand what you mean by saying that it is now fixed,
Well, GDB no longer asserts/crashes (when you build gdb without assert)
when it prints a class.
=> so printing a pascal class in gdb is now fixed.
before my commit, I wasn't able to debug the Free Pascal trunk
compiler using GDB.
Yes, exactly. And that is fixed.
Well, except for records with constants.
Only problem: gdb is broken if the language is set to Pascal.
The valid DWARF-5 works if the language is c++. But of course not, if it
is Pascal.
I am still the official Pascal maintainer of GDB, but I didn't do
anything
to improve GDB for a looonng time.
I would maybe make more sense if you would directly step up to volunteer
as Pascal maintainer of GDB?
As just mentioned, my GDB source knowledge is almost none existent.
Also never done much with any c/c++ variant. I can read it...
Why is there a (reverted) commit that attempts to fix this by removing
the constant from TObject (and leaving the dwarf info as is)?
This is how I did on several test machines to be able to use GDB to
debug Free Pascal compiler.
I pushed this local change by accident, that is why I reverted it.
Ah, ok...
I really was surprised, it didn't make sense as a real fix.
We had a discussion on core when I raised the issue about the fact
that adding a constant
field to the system TObject (which is the base class of all classes)
completely broke the usage of GDB, as any inspection of a class instance
led to a internal assertion error inside GDB.
set language c++
doesn't fix all, but a few things get better.
But it means
p *MyObject
instead of
p MyObject^
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