Hello automakers. Due to current implementation details, when dealing with Yacc sources, automake must know the contents of the `$(AM_YFLAGS)' variable (or similar `$(foo_YFLAGS)' variables) *statically and unconditionally* in order to always generate proper code.
This is due to the special handling of the `-d' yacc flag; on this issue, read at <http://www.gnu.org/software/automake/manual/html_node/Yacc-and-Lex.html>: ``AM_YFLAGS is usually used to pass the -d option to yacc. Automake knows what this means and will automatically adjust its rules to update and distribute the header file built by 'yacc -d'. '' And while automake correctly warns if AM_YFLAGS is conditionally *defined*: $ cat configure.ac AC_INIT(x,0) AM_INIT_AUTOMAKE(foreign) AC_PROG_CC AC_PROG_YACC AC_CONFIG_FILES(Makefile) AM_CONDITIONAL(COND,:) $ aclocal $ cat > Makefile.am <<'END' bin_PROGRAMS = foo bar foo_SOURCES = foo.y bar_SOURCES = bar.y if COND AM_YFLAGS = -d endif END $ automake -a -Werror; echo status=$? Makefile.am:5: automake does not support AM_YFLAGS being defined conditionally status=1 it erronously doesn't warn if AM_YFLAGS is conditionally *extended*: $ cat configure.ac AC_INIT(x,0) AM_INIT_AUTOMAKE(foreign) AC_PROG_CC AC_PROG_YACC AC_CONFIG_FILES(Makefile) AM_CONDITIONAL(COND,:) $ aclocal $ cat > Makefile.am <<'END' bin_PROGRAMS = foo bar foo_SOURCES = foo.y bar_SOURCES = bar.y AM_YFLAGS = if COND AM_YFLAGS += -d endif END $ automake -a -Werror; echo status=$? status=0 I think this bug shouldn't be difficult to fix, and I'll attempt a fix soonish; but as usual, having it in the bug tracker doesn't hurt IMHO. Regards, Stefano
