[PATCH v1 4/7] ld.texi: Add ASCII to info file

[Jan Beulich]

On 05.07.2024 17:38, Ulf Samuelsson wrote:
> 
> Den 2024-07-02 kl. 10:12, skrev Jan Beulich:
>> First: Please don't drop the mailing list from Cc. Second: Please don't
>> top-post.
>>
>> On 02.07.2024 00:21, Ulf Samuelsson wrote:
>>> I submitted the code in this patch series more than a year ago, and it got accepted.
>>> Then a lot was reverted since I had not assigned the copyright to FSF.
>>> For unknown reasons, my ASCIZ patches remained, but the ASCII stuff was reverted.
>>> The reason for the naming is to be similar to how I remember naming in some assemblers where ASCIZ is zero terminated and ASCII is not zero terminated.
>>>
>>> If the string is too long, so it does not fit, it is really an error.
>>> Adding a zero when truncating is a little less intrusive and may reduce runtime errors.
>>> ASCII tells people what it is meant to be doing. ASCIIZ will make a lot of people wonder what the difference is between ASCIZ and ASCIIZ. It will also be misleading, because it does not add a zero if the string fits.
>> Then did I read the code wrong? I was left with the impression that you'll
>> truncate at size-1, to ensure zero termination. Plus as you say in this
>> doc, size being 0 results in ASCIZ behavior, i.e. zero-terminates too.
> 
>               "          111111"
>               "0123456789012345"
> 
>    ASCII (16) "This is a string"
> 
>    results in 'size' == 16. Since the string is 16 characters, 'len' 
> will be 16 as well.

And hence

  else if (len >= size)
    {
      len = size - 1;

would reduce len down to 15 afaics, such that ...


>    This loop will be run 16 times, and i will be 16 at the exit of
> 
>    for (i = 0; i < len; i++)
>      lang_add_data (BYTE, exp_intop (string[i]));
> 
>    Since i == 16, and size == 16, the following loop will not be run 
> even once.
> 
>    while (i++ < size)
>      lang_add_data (BYTE, exp_intop ('\0'));
> 
>    so no '\0' will be added.

... a '\0' will be added here? Otherwise, if I continue to overlook
something, what I can say is that ...

> ===============================
> 
>    ASCII (16) "This is a string."
> 
>    size = 16, len = 17.  len > size, solen is set to 16-1 = 15.
> 
>    copy the first 15 characters in the first loop, add a single '\0' in 
> the second loop.

... this would be pretty odd to me: Why would a nul be inserted in
this case, but not in the one further up?

Jan