Re: Wrong value on a type

[Hans Aberg]

At 15:55 +0100 2001/01/23, Akim Demaille wrote:
>>... All that i did was change
>|  /my_pattern/    { yylval = yytext; return STRING; }
>|
>| by the line
>|
>|  /my_pattern/    { yylval = strdup (yytext); return STRING; }
>|
>| and the problem desapear!. But why do you say that this is not as perfect
>| as they could?
>
>Nope, for reasons similar to those given by Hans.  I agree with him I
>don't remember having seen a written rule somewhere stating that
>yytext is null-terminated, but I never observed the converse.  If you
>carefully read the Flex documentation, there are many samples that
>would break if the yytext was not 0-terminated (yet it shows how to
>use strdup), but I couldn't find any indication about it.

Actually, the code that Flex writes has a macro YY_DO_BEFORE_ACTION which
makes sure yytext is 0-terminated while the action is executed.

  Hans Aberg