Manual

114 Bison 2.3
%token START_FOO START_BAR;
%start start;
start: START_FOO foo
| START_BAR bar;
These tokens prevents the introduction of new conflicts. As far as the parser goes, that
is all that is needed.
Now the difficult part is ensuring that the scanner will send these tokens first. If your
scanner is hand-written, that should be straightforward. If your scanner is generated by
Lex, them there is simple means to do it: recall that anything between ‘%{ ... %}’ after the
first %% is copied verbatim in the top of the generated yylex function. Make sure a variable
start_token is available in the scanner (e.g., a global variable or using %lex-param etc.),
and use the following:
/* Prologue. */
%%
%{
if (start_token)
{
int t = start_token;
start_token = 0;
return t;
}
%}
/* The rules. */
11.6 Secure Conform
Is Bison secure Does it conform to POSIX
If you’re looking for a guarantee or certification, we don’t provide it. However, Bison is
intended to be a reliable program that conforms to the POSIX specification for Yacc. If you
run into problems, please send us a bug report.
11.7 I can’t build Bison
I can’t build Bison because make complains that
msgfmt is not found.
What should I do
Like most GNU packages with internationalization support, that feature is turned
on by default. If you have problems building in the ‘po’ subdirectory, it indicates
that your system’s internationalization support is lacking. You can re-configure Bison
with ‘--disable-nls’ to turn off this support, or you can install GNU gettext from
ftp://ftp.gnu.org/gnu/gettext/ and re-configure Bison. See the file ‘ABOUT-NLS’ for
more information.
11.8 Where can I find help
I’m having trouble using Bison. Where can I find help