[Bug ld/30193] ASCII command length checking corner cases not properly handled

[pexu at sourceware dot mail.kapsi.fi]

https://sourceware.org/bugzilla/show_bug.cgi?id=30193

Pekka Seppänen <pexu at sourceware dot mail.kapsi.fi> changed:

           What    |Removed                     |Added
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             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #4 from Pekka Seppänen <pexu at sourceware dot mail.kapsi.fi> ---
(In reply to Nick Clifton from comment #1)
> (In reply to Pekka Seppänen from comment #0)
> Hi Pekka,
> 
> > of the input string (that has been processed).  As the checking currently
> > uses `len >= size' it is not possible to output a string that is exactly the
> > allocated size, e.g. `ASCII (5) "ascii"'.
> 
> This is deliberate.  The ASCII directive always produces a zero-terminated
> string.  From the documentation:
> 
>     If the string is too long, a warning is issued 
>     and the string is truncated.  The string will 
>     still be zero-terminated in this case.
>

I see, my bad, I was perhaps thinking this being more equal to assembler .ascii
and .asciz.  Of these two only the latter produces zero-terminated string.  It
would have been nice to replace 64-bit hex values (that translate to
non-terminated ascii strings) with ASCII (8) "<value>" where the value is
exactly 8 bytes.

> 
> > Also, as lang_add_string() processes both ASCIZ and ASCII commands it is not
> > possible to produce an empty output, e.g. `ASCII (0) ""'.  This might be
> > useful if the command would be used to produce variable padding.
>  
> I find that very unlikely.  Why would the padding need to be in the form of
> ascii characters ?
> 

This is obviously personal preference, but I usually like to leave my handmark,
or subtle signature, on the software I'm working on.  So, many times, I might
use something that is human readable as padding (or marker, for that matter).

Anyway, I see this sparked an improvement nonetheless and I learned about
testsuite internals, so I don't consider this a wasted effort.

Thanks,
  -- Pekka

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