RFH: Annotating ELF binaries

[Florian Weimer]

On 11/05/2016 12:57 AM, Ian Lance Taylor wrote:
> On Fri, Nov 4, 2016 at 8:02 AM, Nick Clifton <nickc@redhat.com> wrote:
>>
>>   We (the tools team at Red Hat) are working on a project to add
>>   annotations to ELF binaries, so that we can answer various questions
>>   about them.  We have set up a wiki page about the project here:
>>
>> https://fedoraproject.org/wiki/Toolchain/Watermark#Markup_for_ELF_objects
>>
>>   We would very much like this to be something more than just an
>>   internal project, and so we are reaching out to you for your opinions,
>>   suggestions and advice.  If you are interested in being able answer
>>   questions such as 'how was this function compiled ?' or 'is this
>>   library compatible with this application ?' then please take a minute
>>   to have a look at the proposal.
>
> Wearing my Go hat, I observe that you are mixing together general
> properties ("Which (architecture specific) ABI variant is in use in
> object X?") with language-specific properties ("agree upon the format
> of long double?").  I encourage a clear separation of those two
> different kinds of notes.

I'm not sure how to draw the line.  I consider the size and format of 
“long double” very much an ABI matter.

The psABI uses C types throughout, although it is used for much more 
than just C .  There is no language-independent name I know of for the 
floating point type larger than the type which resembles IEEE double 
precision floats.  But I would expect that Ada's definition of 
Long_Long_Float would have to be adjusted to align with ABI changes in 
this area.

Thanks,
Florian