[lldb-dev] The mysterious case of unsupported DW_FORMs

[Leonard Mosescu via lldb-dev]

Great. Thanks for the reminder, here's the llvm-dwarfdump bug
<https://bugs.llvm.org/show_bug.cgi?id=38488>



On Wed, Aug 8, 2018 at 7:11 AM, <paul.robinson at sony.com> wrote:

> I posted this suggestion on dwarf-discuss, where I would hope various tool
> maintainers are watching.
>
>
>
> The maintainer of dwarfdump says that a new version now "prints the type
> of compression and the compression factor for each compressed section
> that's being reported."  Very small sections (< 100 bytes) tend to get
> larger, but he says he's seeing nearly 10x compression factors on string
> sections.  Other sections are in between these extremes.
>
>
>
> Don't know about the GNU tools (readelf, objdump).
>
>
>
> Did you file a bug for llvm-dwarfdump?  I haven't noticed one.
>
> --paulr
>
>
>
> *From:* Leonard Mosescu [mailto:mosescu at google.com]
> *Sent:* Thursday, August 02, 2018 12:53 PM
> *To:* Robinson, Paul
> *Cc:* LLDB
> *Subject:* Re: [lldb-dev] The mysterious case of unsupported DW_FORMs
>
>
>
> Thanks Paul! I have a fix for the LLDB handling of compressed sections in
> an upcoming change (together with improved logging). The email was mostly
> in case some other poor soul hit the same problem (until I get a chance to
> commit the fixes)
>
>
>
> *(*) none of the tools bothered to make a note that the sections are
> compressed (*
> *SHF_COMPRESSED) *That seems like a completely valid feature request.
> Again filing a bug would be the right tactic.  I'm willing to do this one
> for you, if you don't have a bugzilla account.
>
>
>
> I'll open a request for llvm-dwarfdump. If you happen to be in touch with
> the developers of the other tools (readelf, objdump, dwarfdump) feel free
> to forward them the notes.
>
>
>
>
>
>
>
> On Thu, Aug 2, 2018 at 7:21 AM, <paul.robinson at sony.com> wrote:
>
> Why weren't my local LLVM & LLDB builds able to decompress the sections?
> CMake!
>
>
>
> Remembering to delete CMakeCache.txt is usually the part I forget to do.
>
>
>
> LLDB tried to decompress, but when failed to do so it carried on returning
> and alter attempting to parse the compressed bytes as is.
>
>
>
> A section that is compressed but can't be decompressed should be treated
> as corrupt/unparseable.  That seems like an LLDB bug; do you have an
> account on the project bugzilla?
>
>
>
> *(*) none of the tools bothered to make a note that the sections are
> compressed (**SHF_COMPRESSED)*
>
>
>
> That seems like a completely valid feature request.  Again filing a bug
> would be the right tactic.  I'm willing to do this one for you, if you
> don't have a bugzilla account.
>
>
>
> Thanks,
>
> --paulr
>
>
>
>
>
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