Re: [PATCH 08/12] libpoke: Fix printf %v for strings to give valid literals

[Mohammad-Reza Nabipoor]

On Thu, May 27, 2021 at 02:04:46PM +0200, Jose E. Marchesi wrote:
> 
> Hi Mohammad.
> 
> > diff --git a/libpoke/pkl-gen.pks b/libpoke/pkl-gen.pks
> > index 431b0ef7..70f69485 100644
> > --- a/libpoke/pkl-gen.pks
> > +++ b/libpoke/pkl-gen.pks
> > @@ -1893,6 +1893,7 @@
> >          begsc
> >          push "\""
> >          prints
> > +        .call _pkl_escape_string; VAL
> >          prints
> >          push "\""
> >          prints
> > diff --git a/libpoke/pkl-rt.pk b/libpoke/pkl-rt.pk
> > index 033636e0..f8aa32b8 100644
> > --- a/libpoke/pkl-rt.pk
> > +++ b/libpoke/pkl-rt.pk
> > @@ -251,6 +251,40 @@ fun _pkl_base_prefix = (int<32> base) string:
> >     return "";
> >   }
> >  
> > +/* Return a new string in which all the non-printable characters are 
> > replaced
> > +   with a escape sequence (\xXX).  */
> > +
> > +fun _pkl_escape_string = (string str) string:
> > +  {
> > +    var chars = "0123456789abcdef",
> > +        len = str'length,
> > +        len_esc = 0;
> > +
> > +    /* Calculate the length of escaped string.  */
> > +    for (var i = 0UL; i < len; ++i)
> > +      len_esc += str[i] - 0x20UB < 0x5fUB /* is printable */ ? 1 : 4 /* 
> > \xXX */;
> > +
> > +    var esc = "?" * len_esc;
> > +
> > +    for (var i = 0UL, j = 0UL; i < len; ++i)
> > +      {
> > +        if (str[i] - 0x20UB < 0x5fUB)
> > +          {
> > +            __pkl_unsafe_string_set (esc, j, str[i] as string);
> > +            ++j;
> > +          }
> > +        else
> > +          {
> > +            var nib_lo = chars[str[i] & 0xfUB] as string,
> > +                nib_hi = chars[(str[i] .>> 4) & 0xfUB] as string;
> > +
> > +            __pkl_unsafe_string_set (esc, j, "\\x" + nib_hi + nib_lo);
> > +            j += 4;
> > +          }
> > +      }
> > +    return esc;
> > +  }
> 
> Very nice :)
> 
> OK for both master and maint/poke-1 (I think we really should backport
> the strset instruction and __pkl_unsafe_string_set to poke 1.x).
> 

I did backport it.
Pushed.
Thanks.