Re: Bison/flex compatibility revisited

[Bruce Lilly]

W. L. Estes wrote:

> I find this in the bison manual, in the chapter on invoking bison:
>
> `-p PREFIX'
> `--name-prefix=PREFIX'
>      Rename the external symbols used in the parser so that they start
>      with PREFIX instead of `yy'.  The precise list of symbols renamed
>      is `yyparse', `yylex', `yyerror', `yynerrs', `yylval', `yychar'
>      and `yydebug'.
>
> That's from not-the-most-recent version of bison, but it should still
> be useful.

That's achieved by the a bunch of macros near the top of the
bison-generated y.tab.c:

/* If NAME_PREFIX is specified substitute the variables and functions
   names.  */
#define yyparse mailparse
#define yylex   maillex
#define yyerror mailerror
#define yylval  maillval
#define yychar  mailchar
#define yydebug maildebug
#define yynerrs mailnerrs

And if the flex-generated header file is included w/o YY_HEADER_NO_UNDEFS,
its #undefs proceed to trounce those macros.