[PATCH] D28679: [llvm-dwp] - Reuse object::Decompressor class

[George Rimar via llvm-commits]

>> +  Expected<Decompressor> Dec =
>> +      Decompressor::create(Name, Contents, false /*IsLE*/, false /*Is64Bit*/);
>> +  if (!Dec)
>> +    return createError(Name, Dec.takeError());
>
>Why not just return Dec.takeError()?
>
>Cheers,
>Rafael

compressfail.test initially reported something like:
error: failure while decompressing compressed section: 'zdebug_{{.*}}.dwo'

Decompressor::create() can return next text
for this this patch:

"zlib is not available"
"corrupted compressed section header"
"corrupted uncompressed section size"

For first one "return Dec.takeError()" would probably work, but other 2 relative
to corrupted header probably require print of section name too.
Otherwise we end up with inconsistent error messages, like:

"corrupted compressed section header" 
vs 
"failure while decompressing compressed section: 'zdebug_{{.*}}.dwo', <SOME REASON HERE>"

Best regards,
George.