maint: maintainer-release-check.

[bison.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index 78f641d3c1fa9ae4ce674444bb979a44fd5ecb92..3c3fa421474692370f5146c2a57861e60b316d39 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -70,7 +70,7 @@ if test "$enable_gcc_warnings" = yes; then
     -Wcast-qual -Wformat -Wpointer-arith -Wwrite-strings'
   warn_c='-Wbad-function-cast -Wmissing-declarations -Wmissing-prototypes
     -Wshadow -Wstrict-prototypes'
-  warn_cxx=''
+  warn_cxx='-Wnoexcept -Wzero-as-null-pointer-constant'
   AC_LANG_PUSH([C])
   for i in $warn_common $warn_c;
   do
@@ -114,6 +114,7 @@ AC_SUBST([YACC_LIBRARY])
 
 # Checks for programs.
 AC_PROG_LEX
+$LEX_IS_FLEX || AC_MSG_ERROR([Flex is required])
 AC_PROG_YACC
 AC_PROG_RANLIB
 AC_PROG_GNU_M4
@@ -137,7 +138,6 @@ gl_INIT
 # Checks for library functions.
 AC_CHECK_FUNCS_ONCE([setlocale])
 AM_WITH_DMALLOC
-BISON_PREREQ_SUBPIPE
 BISON_PREREQ_TIMEVAR
 
 # Gettext.