From eb301edc44e18bfbed021e1ebef092982ec1df91 Mon Sep 17 00:00:00 2001
From: phantom <phantom10111@gmail.com>
Date: Sat, 29 Jun 2013 18:37:57 +0200
Subject: [PATCH] Enable LTO switch for configure script and automake 1.14 fix

---
 .hgignore       |  3 ++-
 configure.ac    | 31 +++++++++++++++++++++++++++++++
 src/Makefile.am |  2 ++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/.hgignore b/.hgignore
index 8350e07d42..41862eba46 100644
--- a/.hgignore
+++ b/.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
diff --git a/configure.ac b/configure.ac
index 2f19c2f5b5..bd19709a49 100644
--- a/configure.ac
+++ b/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])
diff --git a/src/Makefile.am b/src/Makefile.am
index 11f52385fa..7c86fa913f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,3 +1,5 @@
+AUTOMAKE_OPTIONS = subdir-objects
+
 ## Do not install stepmania in the traditional way.
 noinst_PROGRAMS = stepmania
 TESTS =