maint: avoid "magic number exit".

[bison.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index 2540698d702a09fc93c4a4237e2acfda2b946386..1fffa67cd461f7b25be5666116678034b2f5ea3b 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -20,14 +20,15 @@
 # keyword in at least string.h from gnulib.  We need Autoconf 2.68 or
 # better to avoid a typo in the `configure --help' entry for the YACC
 # environment variable.
-AC_PREREQ(2.68)
+AC_PREREQ([2.68])
+m4_pattern_forbid([^gl_[A-Z]])
 
 AC_INIT([GNU Bison],
         m4_esyscmd([build-aux/git-version-gen .tarball-version]),
         [bug-bison@gnu.org])
-AC_DEFINE([PACKAGE_COPYRIGHT_YEAR], [2012],
-          [The copyright year for this package])
 AC_SUBST([PACKAGE_COPYRIGHT_YEAR], [2012])
+AC_DEFINE_UNQUOTED([PACKAGE_COPYRIGHT_YEAR], [$PACKAGE_COPYRIGHT_YEAR],
+                   [The copyright year for this package])
 
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([m4])
@@ -44,9 +45,10 @@ AC_CONFIG_MACRO_DIR([m4])
 # releases, we want to be able run make dist without being required to
 # add a bogus NEWS entry.  In that case, the version string
 # automatically contains a dash, which we also let disable gnits.
-AM_INIT_AUTOMAKE([1.11.1 dist-xz]
+AM_INIT_AUTOMAKE([1.11.1 dist-xz silent-rules]
                  m4_bmatch(m4_defn([AC_PACKAGE_VERSION]), [[-_]],
                            [gnu], [gnits]))
+AM_SILENT_RULES([yes])
 AC_CONFIG_HEADERS([lib/config.h:lib/config.hin])
 
 # Checks for the compiler.
@@ -55,14 +57,14 @@ AC_PROG_CC_STDC
 # Gnulib (early checks).
 gl_EARLY
 
-AC_ARG_ENABLE(gcc-warnings,
+AC_ARG_ENABLE([gcc-warnings],
 [  --enable-gcc-warnings   turn on lots of GCC warnings (not recommended)],
-[case "${enableval}" in
+[case $enable_gcc_warnings in
    yes|no) ;;
-   *)      AC_MSG_ERROR([bad value ${enableval} for gcc-warnings option]) ;;
+   *)  AC_MSG_ERROR([invalid value for --gcc-warnings: $enable_gcc_warnings]);;
  esac],
-             [enableval=no])
-if test "${enableval}" = yes; then
+              [enable_gcc_warnings=no])
+if test "$enable_gcc_warnings" = yes; then
   gl_WARN_ADD([-Werror], [WERROR_CFLAGS])
   AC_SUBST([WERROR_CFLAGS])
   gl_WARN_ADD([-Wall])