diff -r 000000000000 -r 6474c204b198 build/autoconf/ccache.m4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/build/autoconf/ccache.m4	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+dnl This Source Code Form is subject to the terms of the Mozilla Public
+dnl License, v. 2.0. If a copy of the MPL was not distributed with this
+dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+dnl ======================================================
+dnl = Enable compiling with ccache
+dnl ======================================================
+AC_DEFUN([MOZ_CHECK_CCACHE],
+[
+MOZ_ARG_WITH_STRING(ccache,
+[  --with-ccache[=path/to/ccache]
+                          Enable compiling with ccache],
+    CCACHE=$withval, CCACHE="no")
+
+if test "$CCACHE" != "no"; then
+    if test -z "$CCACHE" -o "$CCACHE" = "yes"; then
+        CCACHE=
+    else
+        if test ! -e "$CCACHE"; then
+            AC_MSG_ERROR([$CCACHE not found])
+        fi
+    fi
+    MOZ_PATH_PROGS(CCACHE, $CCACHE ccache)
+    if test -z "$CCACHE" -o "$CCACHE" = ":"; then
+        AC_MSG_ERROR([ccache not found])
+    elif test -x "$CCACHE"; then
+        CC="$CCACHE $CC"
+        CXX="$CCACHE $CXX"
+        MOZ_USING_CCACHE=1
+    else
+        AC_MSG_ERROR([$CCACHE is not executable])
+    fi
+fi
+
+AC_SUBST(MOZ_USING_CCACHE)
+])