Enable LTO switch for configure script and automake 1.14 fix

.hgignore

@@ -60,7 +60,8 @@ src/libtomcrypt/Release-*
 src/libtommath/build-*
 src/libtommath/Release-*
 src/*.old
-src/.deps
+*/.deps
+*/.dirstamp
 src/*.a
 src/*.so
 GtkModule.so

configure.ac

@@ -48,6 +48,37 @@ case $compile in
 	;;
 esac
 
+AC_ARG_ENABLE(lto, AS_HELP_STRING([--enable-lto], [Enable LTO]), enable_lto=$enableval, enable_lto=no)
+if test x$enable_lto = xyes; then
+	if test "$CXX" != "g++"; then
+		AC_MSG_ERROR([g++ compiler is needed to use lto (if you have it installed, pass CXX=g++ to ./configure)])
+	fi
+	gxx_version="`g++ -dumpversion`"
+	gxx_version_major=$(echo $gxx_version | cut -d'.' -f1)
+	gxx_version_minor=$(echo $gxx_version | cut -d'.' -f2)
+	if test [ "$gxx_version_major" -lt "4" ] || test [ "$gxx_version_minor" -lt "5" ]; then
+		AC_MSG_ERROR([Your g++ version is too old and doesn't support lto])
+	fi
+	CFLAGS="$CFLAGS -O0 -flto"
+	CXXFLAGS="$CXXFLAGS -O0 -flto"
+	LDFLAGS="$LDFLAGS -flto"
+	case $compile in
+		release)
+		LDFLAGS="$LDFLAGS -O3"
+		;;
+		debug)
+		LDFLAGS="$LDFLAGS -g"
+		;;
+		fast)
+		LDFLAGS="$LDFLAGS -O2 -fno-inline"
+		;;
+	esac
+	if test [ "$gxx_version_minor" -ge "8" ]; then
+		CFLAGS="$CFLAGS -fno-fat-lto-objects"
+		CXXFLAGS="$CXXFLAGS -fno-fat-lto-objects"
+	fi
+fi
+
 
 # Some (broken?) versions of gcc treat char as unsigned, check for that.
 AC_LANG_PUSH([C])

src/Makefile.am

@@ -1,3 +1,5 @@
+AUTOMAKE_OPTIONS = subdir-objects
+
 ## Do not install stepmania in the traditional way.
 noinst_PROGRAMS = stepmania
 TESTS =