objdump: DWARF error: could not find variable specification at offset ...

objdump: DWARF error: could not find variable specification at offset ...

[Freddie Chopin]

Hello!

I have multiple embedded projects that - as part of the compilation
process - produce also assembly listing with command similar to this
one:

$ arm-none-eabi-objdump -S --demangle distortosTest.elf > distortosTest.lss

This worked flawlessly up to (and including) previous release of
binutils. In 2.35 something changed. The assembly listing is still
generated and it seems to be correct (I did not check it very
thoroughly), the command ends with no fatal errors (it returns "0" to
the shell), however I see multiple errors like these:

arm-none-eabi-objdump: DWARF error: could not find variable specification at offset 2f9
arm-none-eabi-objdump: DWARF error: could not find variable specification at offset 305
arm-none-eabi-objdump: DWARF error: could not find variable specification at offset 311
...

If I take the .elf file produced by the "new" toolchain (it also
includes GCC 10.2) and do the command above but with objdump from the
"old" toolchain (binutils 2.34), then there is no error. In a reversed
scenario (.elf produced by "old" toolchain, passed to "new" objdump) I
see 10x more errors like the ones above.

I have no idea what does it mean, whether its a problem or not, what
variables are a problem here and how to solve it. Any hints will be
appreciated, I probably should provide some more details, but I don't
really know where to start...

P.S. Please keep me CCed.

Regards,
FCh

Re: objdump: DWARF error: could not find variable specification at offset ...

[Alan Modra]

On Mon, Aug 17, 2020 at 08:15:59PM +0200, Freddie Chopin via Binutils wrote:
> arm-none-eabi-objdump: DWARF error: could not find variable specification at offset 2f9

This is Nick's https://sourceware.org/bugzilla/show_bug.cgi?id=25676
patch.  Please open a new bug attaching an example object file showing
the warning.

-- 
Alan Modra
Australia Development Lab, IBM

Re: objdump: DWARF error: could not find variable specification at offset ...

[Nick Clifton]

Hi Freddie,

> arm-none-eabi-objdump: DWARF error: could not find variable specification at offset 2f9

  I think that these messages are probably another instance of this bug:

https://sourceware.org/bugzilla/show_bug.cgi?id=26520

  Please could you try using the latest binutils sources and see if that fixes the problem.

Cheers
  Nick


 

Re: objdump: DWARF error: could not find variable specification at offset ...

[Freddie Chopin]

On Tue, 2020-09-22 at 13:36 +0100, Nick Clifton wrote:
> Hi Freddie,
> 
> > arm-none-eabi-objdump: DWARF error: could not find variable
> > specification at offset 2f9
> 
>   I think that these messages are probably another instance of this
> bug:
> 
> https://sourceware.org/bugzilla/show_bug.cgi?id=26520
> 
>   Please could you try using the latest binutils sources and see if
> that fixes the problem.

Hmm... but that's the bug I reported after the first reply from Alan in
this thread, and I already wrote in bugzilla that after applying the
patch the problem is gone. Maybe you meant to post a link to a
different bug report?

Regards,
FCh