On Wed, Jan 11, 2012 at 1:49 AM, Kenneth Graunke <kenn...@whitecape.org> wrote: > On 01/10/2012 10:16 PM, Matt Turner wrote: >> >> Defining these macros lets us use AC_PROG_YACC/LEX which makes automake >> easier while still specifically requiring bison and flex. >> >> Based on bison.m4 and flex.m4 found in LLVM's tree. >> >> Signed-off-by: Matt Turner<matts...@gmail.com> >> --- >> configure.ac | 9 ++++----- >> m4/bison.m4 | 16 ++++++++++++++++ >> m4/flex.m4 | 16 ++++++++++++++++ >> 3 files changed, 36 insertions(+), 5 deletions(-) >> create mode 100644 m4/bison.m4 >> create mode 100644 m4/flex.m4 >> >> diff --git a/configure.ac b/configure.ac >> index 511d147..c0abeb9 100644 >> --- a/configure.ac >> +++ b/configure.ac >> @@ -45,11 +45,10 @@ if test "x$MKDEP" = "x"; then >> AC_MSG_ERROR([makedepend is required to build Mesa]) >> fi >> >> -AC_PATH_PROG([FLEX], [flex]) >> -test "x$FLEX" = "x"&& AC_MSG_ERROR([flex is needed to build Mesa]) >> - >> -AC_PATH_PROG([BISON], [bison]) >> -test "x$BISON" = "x"&& AC_MSG_ERROR([bison is needed to build Mesa]) >> +m4_include([m4/bison.m4]) >> +AC_PROG_BISON >> +m4_include([m4/flex.m4]) >> +AC_PROG_FLEX >> >> dnl Our fallback install-sh is a symlink to minstall. Use the existing >> dnl configuration in that case. >> diff --git a/m4/bison.m4 b/m4/bison.m4 >> new file mode 100644 >> index 0000000..641d438 >> --- /dev/null >> +++ b/m4/bison.m4 >> @@ -0,0 +1,16 @@ >> +# >> +# Check for Bison. >> +# >> +# This macro verifies that Bison is installed. If successful, then >> +# 1) YACC is set to bison -y (to emulate YACC calls) > > > I don't think we want to emulate POSIX yacc. We're not using -y today, and > I expect it'd only break things... > > >> +# 2) BISON is set to bison >> +# >> +AC_DEFUN([AC_PROG_BISON], >> +[AC_PROG_YACC() >> +if test "$YACC" != "bison -y"; then >> + AC_SUBST(BISON,[]) >> + AC_MSG_WARN([bison not found]) >> +else >> + AC_SUBST(BISON,[bison]) >> +fi >> +]) >> diff --git a/m4/flex.m4 b/m4/flex.m4 >> new file mode 100644 >> index 0000000..6a2a004 >> --- /dev/null >> +++ b/m4/flex.m4 >> @@ -0,0 +1,16 @@ >> +# >> +# Check for FLEX. >> +# >> +# This macro verifies that flex is installed. If successful, then >> +# 1) LEX is set to flex (to emulate lex calls) >> +# 2) FLEX is set to flex >> +# >> +AC_DEFUN([AC_PROG_FLEX], >> +[AC_PROG_LEX() >> +if test "$LEX" != "flex"; then >> + AC_SUBST(FLEX,[]) >> + AC_MSG_ERROR([flex not found]) >> +else >> + AC_SUBST(FLEX,[flex]) >> +fi >> +]) > > > I like the idea of AC_PROG_FLEX and AC_PROG_BISON macros, but I don't care > for this implementation. I would expect them to perform some kind of > feature check, or ask the program whether it's flex/bison. This just > matches on the name, so if I had flex installed only as "lex", or bison > installed as "bison25" or such, this would break. > > Maybe this is okay, but at least in my mind, only allowing one name seems to > kind of defeat the point of a configure check. Not entirely, but still.
Agree, this isn't very good. Using AC_PROG_PATH for bison and flex doesn't make automake happy, but using AC_PROG_YACC/LEX works fine. Oh, and when experimenting with this I discovered that bison -y worked while plain bison didn't. Who knows. I suggest we just do what my previous automake patch does with AC_PROG_YACC/LEX and just let builders ensure that they're using flex and bison. In Gentoo, we've found that this is very common. Matt _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
