Makefile.am: drop AM_LFLAGS

We don't use a lex/flex anymore so this is not used.

Signed-off-by: Ran Benita <ran234@gmail.com>
parser: don't use enum yytokentype

byacc doesn't support this, it just puts out #define's for the tokens.

Signed-off-by: Ran Benita <ran234@gmail.com>
parser: use %pure-parser instead of %define api.pure

Both bison and byacc support this syntax. Bison manpage says something
about this giving more or less options, but we don't care.

Signed-off-by: Ran Benita <ran234@gmail.com>
parser: drop %name-prefix, use -p yacc argument instead

Even though the %name-prefix is more sensible, byacc doesn't support it,
but both bison and byacc support the -p argument.

Signed-off-by: Ran Benita <ran234@gmail.com>
parser: don't use %locations

byacc doesn't support this feature.

We print the line/col of the last scanned token instead. This is slightly
less in case of *parser* errors (not syntax errors), but I couldn't make
it point to another line, and this are pretty cryptic anyways. So it's
good enough. Also might be a bit faster, but haven't checked.

Signed-off-by: Ran Benita <ran234@gmail.com>
parser: add a workaround for byacc

Unlike bison, byacc outputs its own parser code *after* our own parser.y
code, which includes the #undef. So this fix is needed for the 'scanner'
-> 'param->scanner' translation to work in the parser.c code generated
by byacc.

Signed-off-by: Ran Benita <ran234@gmail.com>
parser: add some notes about byacc working

We now also work with byacc (version tested: 20130925) which some people
prefer, perhaps due to its license (public domain) or performance
(haven't compared).

When using byacc, currently the following warning comes up:
    src/xkbcomp/parser.c:954:14: warning: declaration shadows a variable in the global scope [-Wshadow]
        YYSTYPE  yylval;
                ^
    src/xkbcomp/parser.c:37:20: note: expanded from macro 'yylval'
    #define yylval     _xkbcommon_lval
                    ^
    ./src/xkbcomp/parser.h:96:16: note: previous declaration is here
    extern YYSTYPE _xkbcommon_lval;

This is due to a bug in byacc - it shouldn't output that extern line in
%pure-parser mode. So the warning stays.

Signed-off-by: Ran Benita <ran234@gmail.com>