Make Flex and Bison tests inconditional

By GNU/automake design, those tools have to be present when building
from VCS, even if the generated code is not actually compiled. This
fixes #19086.

Also this potentially allows more than one module to use them.

configure.ac

@@ -65,6 +65,8 @@ AC_PROG_EGREP
 AC_PROG_MAKE_SET
 AC_PROG_INSTALL
 AM_PROG_AS
+AC_PROG_LEX
+AC_PROG_YACC
 
 AC_ARG_VAR([DESKTOP_FILE_VALIDATE], [Validator for desktop entry files])
 AC_CHECK_PROGS(DESKTOP_FILE_VALIDATE, [${DESKTOP_FILE_VALIDATE} desktop-file-validate], :)
@@ -2979,10 +2981,8 @@ dnl
 AC_ARG_ENABLE(css,
 [  --enable-css            CSS selector engine (default auto)])
 AS_IF([test "${enable_css}" != "no"], [
-  AC_PROG_LEX
   with_css="no"
   AS_IF([test "x$LEX" != "x:"], [
-    AC_PROG_YACC
     dnl can only accept bison or we need byacc feature test for %destructor
     AS_IF([test "x$YACC" = "xbison -y"], [
         AC_DEFINE(HAVE_CSS, 1, [Define if CSS engine is built])

modules/codec/Makefile.am

@@ -228,9 +228,7 @@ libwebvtt_plugin_la_SOURCES = codec/webvtt/subsvtt.c \
                               demux/webvtt.c \
                               demux/mp4/minibox.h
 codec_LTLIBRARIES += libwebvtt_plugin.la
-AM_YFLAGS = -d
 if ENABLE_CSS
-SUFFIXES += .l .y
 # dependency: we need grammar build first
 BUILT_SOURCES += codec/webvtt/CSSGrammar.h
 libwebvtt_plugin_la_CFLAGS = $(AM_CFLAGS) -I$(srcdir)/codec/webvtt/ -I$(builddir)/codec/webvtt/

modules/common.am

@@ -35,5 +35,6 @@ AM_LDFLAGS = \
 if HAVE_WIN32
 AM_LDFLAGS += $(top_builddir)/modules/module.rc.lo -Wc,-static
 endif
+AM_YFLAGS = -d
 
-SUFFIXES =
+SUFFIXES = .l .y