Hello Clifford, * Clifford Yapp wrote on Wed, Mar 10, 2010 at 02:28:00AM CET: > I have a problem with some Lex and Yacc files. They require newer > versions of flex/bison/m4 be present on the system to correctly > generate code, and that's not something that can always be assumed. > I've cooked up some configure logic to check the version of flex > available in configure.ac. What I'm trying to do is have the build > run flex and bison if the versions available are high enough, and if > that's not possible I'd like to fall back to building alternate static > copies of the generated source code. This functions in normal build > situations, but a make distcheck on a machine where flex and yacc are > not up to par still results in make attempting to process the .ll and > .yy files, despite the conditional logic. > > Is there a way at the Makefile.am level to prevent the distcheck > target running flex and bison on these files?
Right after AM_PROG_LEX or AC_PROG_LEX in configure.ac, check for the version requirements, and if they are not met, set LEX to $(top_srcdir)/$auxdir/missing --run flex with $auxdir being the directory set with AC_CONFIG_AUX_DIR. Hmm, neither Autoconf nor Autoconf provide a public variable for this. You might need $(abs_top_srcdir) if lex is used in weird ways. Yacc/bison should work similarly. Completely untested; please report back whether that worked as intended. Thanks. If it doesn't, a small example package to look at would be good. Cheers, Ralf
