fexec bug in v5.15?

[Carlos Antunes]

Adrain,

Just wanted to clarify that v5.14 with that scanner patch you provided
also exhibits the problem so I guess that patch is the culprit.

Thanks!

Carlos

Carlos Antunes wrote:
> Adrian,
>
> I have the following defined:
>
> consume_sp_optional := |*
>
>             ( ( '\r'? '\n' )? [ \t] )* { printf("===== sp_optional
> (%s)\n", p); };
>
>             '\r'? '\n' { printf("===== crlf (%s)\n", p); fexec
> tokstart; fret; };
>
>             any { printf("<---- sp_optional (%s)\n", p); fexec
> tokstart; fret; };
>
>         *|;
>
> This machine basically eats up optional spaces and tabs including
> folding and returns when CRLF is encountered. This worked fine with
> v5.14. With version 5.15, however, I think there might be a bug in the
> way fexec is working. Looking at the generated C code, I see
> (corresponding to the \r'? '\n' line ):
>
> tr6811:
> #line 26 "test.rl"
>         {tokend = p;{ printf("===== crlf (%s)\n", p); {p =
> ((tokstart))-1;} {p--;{cs = stack[--top]; goto _again;}} }p--;}
>         goto st6170;
>
>
> Now, there is this p = ((tokstart))-1 followed by a p-- (and another
> p-- that is never reached). Shouldn't the first expression be just p =
> tokstart? The purpose of the fexec in my code is to backtrack and make
> the CRLF available for further matching.
>
> Thanks!
>
> Carlos
>
>
>
> --
> "We hold [...] that all men are created equal; that they are
> endowed [...] with certain inalienable rights; that among
> these are life, liberty, and the pursuit of happiness"
>         -- Thomas Jefferson