diff --git a/aclocal.m4 b/aclocal.m4
index b656bc7d348..c1e6c07bd7f 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -3,6 +3,8 @@ dnl Local autoconf macros used with mozilla
 dnl The contents of this file are under the Public Domain.
 dnl 
 
+builtin(include, build/autoconf/toolchain.m4)dnl
+builtin(include, build/autoconf/ccache.m4)dnl
 builtin(include, build/autoconf/nspr.m4)dnl
 builtin(include, build/autoconf/nss.m4)dnl
 builtin(include, build/autoconf/pkg.m4)dnl
diff --git a/build/autoconf/ccache.m4 b/build/autoconf/ccache.m4
new file mode 100644
index 00000000000..5e24691955b
--- /dev/null
+++ b/build/autoconf/ccache.m4
@@ -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)
+])
diff --git a/build/autoconf/toolchain.m4 b/build/autoconf/toolchain.m4
new file mode 100644
index 00000000000..a9498a80fd3
--- /dev/null
+++ b/build/autoconf/toolchain.m4
@@ -0,0 +1,62 @@
+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/.
+
+AC_DEFUN([MOZ_TOOL_VARIABLES],
+[
+GNU_AS=
+GNU_LD=
+GNU_CC=
+GNU_CXX=
+CC_VERSION='N/A'
+CXX_VERSION='N/A'
+if test "$GCC" = "yes"; then
+    GNU_CC=1
+    CC_VERSION=`$CC -v 2>&1 | grep 'gcc version'`
+fi
+if test "$GXX" = "yes"; then
+    GNU_CXX=1
+    CXX_VERSION=`$CXX -v 2>&1 | grep 'gcc version'`
+fi
+if test "`echo | $AS -o conftest.out -v 2>&1 | grep -c GNU`" != "0"; then
+    GNU_AS=1
+fi
+rm -f conftest.out
+if test "`echo | $LD -v 2>&1 | grep -c GNU`" != "0"; then
+    GNU_LD=1
+fi
+if test "$GNU_CC"; then
+    if `$CC -print-prog-name=ld` -v 2>&1 | grep -c GNU >/dev/null; then
+        GCC_USE_GNU_LD=1
+    fi
+fi
+
+INTEL_CC=
+INTEL_CXX=
+if test "$GCC" = yes; then
+   if test "`$CC -help 2>&1 | grep -c 'Intel(R) C++ Compiler'`" != "0"; then
+     INTEL_CC=1
+   fi
+fi
+
+if test "$GXX" = yes; then
+   if test "`$CXX -help 2>&1 | grep -c 'Intel(R) C++ Compiler'`" != "0"; then
+     INTEL_CXX=1
+   fi
+fi
+
+CLANG_CC=
+CLANG_CXX=
+if test "$GCC" = yes; then
+   if test "`$CC -v 2>&1 | grep -c 'clang version'`" != "0"; then
+     CLANG_CC=1
+   fi
+fi
+
+if test "$GXX" = yes; then
+   if test "`$CXX -v 2>&1 | grep -c 'clang version'`" != "0"; then
+     CLANG_CXX=1
+   fi
+fi
+AC_SUBST(CLANG_CXX)
+])
diff --git a/config/autoconf.mk.in b/config/autoconf.mk.in
index 3c18f9f3ca9..8eac4085a8e 100644
--- a/config/autoconf.mk.in
+++ b/config/autoconf.mk.in
@@ -84,6 +84,8 @@ MOZ_ETW         = @MOZ_ETW@
 MOZ_TRACE_JSCALLS = @MOZ_TRACE_JSCALLS@
 DEHYDRA_PATH    = @DEHYDRA_PATH@
 
+MOZ_USING_CCACHE = @MOZ_USING_CCACHE@
+CLANG_CXX = @CLANG_CXX@
 MOZ_LINKER = @MOZ_LINKER@
 MOZ_OLD_LINKER = @MOZ_OLD_LINKER@
 MOZ_ENABLE_SZIP = @MOZ_ENABLE_SZIP@
diff --git a/config/config.mk b/config/config.mk
index af01015dbdc..451a63e3964 100644
--- a/config/config.mk
+++ b/config/config.mk
@@ -562,6 +562,13 @@ ifdef MACOSX_DEPLOYMENT_TARGET
 export MACOSX_DEPLOYMENT_TARGET
 PBBUILD_SETTINGS += MACOSX_DEPLOYMENT_TARGET="$(MACOSX_DEPLOYMENT_TARGET)"
 endif # MACOSX_DEPLOYMENT_TARGET
+
+ifdef MOZ_USING_CCACHE
+ifdef CLANG_CXX
+export CCACHE_CPP2=1
+endif
+endif
+
 ifdef MOZ_OPTIMIZE
 ifeq (2,$(MOZ_OPTIMIZE))
 # Only override project defaults if the config specified explicit settings
diff --git a/configure.in b/configure.in
index 5a6ae4a9e84..bef1cbd513b 100644
--- a/configure.in
+++ b/configure.in
@@ -363,60 +363,7 @@ else
     fi
 fi
 
-GNU_AS=
-GNU_LD=
-GNU_CC=
-GNU_CXX=
-CC_VERSION='N/A'
-CXX_VERSION='N/A'
-if test "$GCC" = "yes"; then
-    GNU_CC=1
-    CC_VERSION=`$CC -v 2>&1 | grep 'gcc version'`
-fi
-if test "$GXX" = "yes"; then
-    GNU_CXX=1
-    CXX_VERSION=`$CXX -v 2>&1 | grep 'gcc version'`
-fi
-if test "`echo | $AS -o conftest.out -v 2>&1 | grep -c GNU`" != "0"; then
-    GNU_AS=1
-fi
-rm -f conftest.out
-if test "`echo | $LD -v 2>&1 | grep -c GNU`" != "0"; then
-    GNU_LD=1
-fi
-if test "$GNU_CC"; then
-    if `$CC -print-prog-name=ld` -v 2>&1 | grep -c GNU >/dev/null; then
-        GCC_USE_GNU_LD=1
-    fi
-fi
-
-INTEL_CC=
-INTEL_CXX=
-if test "$GCC" = yes; then
-   if test "`$CC -help 2>&1 | grep -c 'Intel(R) C++ Compiler'`" != "0"; then
-     INTEL_CC=1
-   fi
-fi
-
-if test "$GXX" = yes; then
-   if test "`$CXX -help 2>&1 | grep -c 'Intel(R) C++ Compiler'`" != "0"; then
-     INTEL_CXX=1
-   fi
-fi
-
-CLANG_CC=
-CLANG_CXX=
-if test "$GCC" = yes; then
-   if test "`$CC -v 2>&1 | grep -c 'clang version'`" != "0"; then
-     CLANG_CC=1
-   fi
-fi
-
-if test "$GXX" = yes; then
-   if test "`$CXX -v 2>&1 | grep -c 'clang version'`" != "0"; then
-     CLANG_CXX=1
-   fi
-fi
+MOZ_TOOL_VARIABLES
 
 dnl ========================================================
 dnl Special win32 checks
@@ -7167,32 +7114,7 @@ if test -n "$JS_CRASH_DIAGNOSTICS"; then
     AC_DEFINE(JS_CRASH_DIAGNOSTICS)
 fi
 
-dnl ======================================================
-dnl = Enable compiling with ccache
-dnl ======================================================
-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 $CXX"
-    else
-        AC_MSG_ERROR([$CCACHE is not executable])
-    fi
-fi
+MOZ_CHECK_CCACHE
 
 dnl ========================================================
 dnl = Enable static checking using gcc-dehydra
diff --git a/js/src/aclocal.m4 b/js/src/aclocal.m4
index 857649e0b33..63162189172 100644
--- a/js/src/aclocal.m4
+++ b/js/src/aclocal.m4
@@ -3,6 +3,8 @@ dnl Local autoconf macros used with mozilla
 dnl The contents of this file are under the Public Domain.
 dnl
 
+builtin(include, build/autoconf/toolchain.m4)dnl
+builtin(include, build/autoconf/ccache.m4)dnl
 builtin(include, build/autoconf/pkg.m4)dnl
 builtin(include, build/autoconf/nspr.m4)dnl
 builtin(include, build/autoconf/altoptions.m4)dnl
diff --git a/js/src/build/autoconf/ccache.m4 b/js/src/build/autoconf/ccache.m4
new file mode 100644
index 00000000000..5e24691955b
--- /dev/null
+++ b/js/src/build/autoconf/ccache.m4
@@ -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)
+])
diff --git a/js/src/build/autoconf/toolchain.m4 b/js/src/build/autoconf/toolchain.m4
new file mode 100644
index 00000000000..a9498a80fd3
--- /dev/null
+++ b/js/src/build/autoconf/toolchain.m4
@@ -0,0 +1,62 @@
+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/.
+
+AC_DEFUN([MOZ_TOOL_VARIABLES],
+[
+GNU_AS=
+GNU_LD=
+GNU_CC=
+GNU_CXX=
+CC_VERSION='N/A'
+CXX_VERSION='N/A'
+if test "$GCC" = "yes"; then
+    GNU_CC=1
+    CC_VERSION=`$CC -v 2>&1 | grep 'gcc version'`
+fi
+if test "$GXX" = "yes"; then
+    GNU_CXX=1
+    CXX_VERSION=`$CXX -v 2>&1 | grep 'gcc version'`
+fi
+if test "`echo | $AS -o conftest.out -v 2>&1 | grep -c GNU`" != "0"; then
+    GNU_AS=1
+fi
+rm -f conftest.out
+if test "`echo | $LD -v 2>&1 | grep -c GNU`" != "0"; then
+    GNU_LD=1
+fi
+if test "$GNU_CC"; then
+    if `$CC -print-prog-name=ld` -v 2>&1 | grep -c GNU >/dev/null; then
+        GCC_USE_GNU_LD=1
+    fi
+fi
+
+INTEL_CC=
+INTEL_CXX=
+if test "$GCC" = yes; then
+   if test "`$CC -help 2>&1 | grep -c 'Intel(R) C++ Compiler'`" != "0"; then
+     INTEL_CC=1
+   fi
+fi
+
+if test "$GXX" = yes; then
+   if test "`$CXX -help 2>&1 | grep -c 'Intel(R) C++ Compiler'`" != "0"; then
+     INTEL_CXX=1
+   fi
+fi
+
+CLANG_CC=
+CLANG_CXX=
+if test "$GCC" = yes; then
+   if test "`$CC -v 2>&1 | grep -c 'clang version'`" != "0"; then
+     CLANG_CC=1
+   fi
+fi
+
+if test "$GXX" = yes; then
+   if test "`$CXX -v 2>&1 | grep -c 'clang version'`" != "0"; then
+     CLANG_CXX=1
+   fi
+fi
+AC_SUBST(CLANG_CXX)
+])
diff --git a/js/src/config/autoconf.mk.in b/js/src/config/autoconf.mk.in
index 431d89f11a2..808f3dcf3d6 100644
--- a/js/src/config/autoconf.mk.in
+++ b/js/src/config/autoconf.mk.in
@@ -49,6 +49,8 @@ MOZ_ETW       = @MOZ_ETW@
 JS_HAS_CTYPES = @JS_HAS_CTYPES@
 DEHYDRA_PATH    = @DEHYDRA_PATH@
 
+MOZ_USING_CCACHE = @MOZ_USING_CCACHE@
+CLANG_CXX = @CLANG_CXX@
 NS_TRACE_MALLOC = @NS_TRACE_MALLOC@
 INCREMENTAL_LINKER = @INCREMENTAL_LINKER@
 MACOSX_DEPLOYMENT_TARGET = @MACOSX_DEPLOYMENT_TARGET@
diff --git a/js/src/config/config.mk b/js/src/config/config.mk
index af01015dbdc..451a63e3964 100644
--- a/js/src/config/config.mk
+++ b/js/src/config/config.mk
@@ -562,6 +562,13 @@ ifdef MACOSX_DEPLOYMENT_TARGET
 export MACOSX_DEPLOYMENT_TARGET
 PBBUILD_SETTINGS += MACOSX_DEPLOYMENT_TARGET="$(MACOSX_DEPLOYMENT_TARGET)"
 endif # MACOSX_DEPLOYMENT_TARGET
+
+ifdef MOZ_USING_CCACHE
+ifdef CLANG_CXX
+export CCACHE_CPP2=1
+endif
+endif
+
 ifdef MOZ_OPTIMIZE
 ifeq (2,$(MOZ_OPTIMIZE))
 # Only override project defaults if the config specified explicit settings
diff --git a/js/src/configure.in b/js/src/configure.in
index 83a68f711e4..2689e8b133c 100644
--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -340,60 +340,7 @@ else
     fi
 fi
 
-GNU_AS=
-GNU_LD=
-GNU_CC=
-GNU_CXX=
-CC_VERSION='N/A'
-CXX_VERSION='N/A'
-if test "$GCC" = "yes"; then
-    GNU_CC=1
-    CC_VERSION=`$CC -v 2>&1 | grep 'gcc version'`
-fi
-if test "$GXX" = "yes"; then
-    GNU_CXX=1
-    CXX_VERSION=`$CXX -v 2>&1 | grep 'gcc version'`
-fi
-if test "`echo | $AS -o conftest.out -v 2>&1 | grep -c GNU`" != "0"; then
-    GNU_AS=1
-fi
-rm -f conftest.out
-if test "`echo | $LD -v 2>&1 | grep -c GNU`" != "0"; then
-    GNU_LD=1
-fi
-if test "$GNU_CC"; then
-    if `$CC -print-prog-name=ld` -v 2>&1 | grep -c GNU >/dev/null; then
-        GCC_USE_GNU_LD=1
-    fi
-fi
-
-INTEL_CC=
-INTEL_CXX=
-if test "$GCC" = yes; then
-   if test "`$CC -help 2>&1 | grep -c 'Intel(R) C++ Compiler'`" != "0"; then
-     INTEL_CC=1
-   fi
-fi
-
-if test "$GXX" = yes; then
-   if test "`$CXX -help 2>&1 | grep -c 'Intel(R) C++ Compiler'`" != "0"; then
-     INTEL_CXX=1
-   fi
-fi
-
-CLANG_CC=
-CLANG_CXX=
-if test "$GCC" = yes; then
-   if test "`$CC -v 2>&1 | grep -c 'clang version'`" != "0"; then
-     CLANG_CC=1
-   fi
-fi
-
-if test "$GXX" = yes; then
-   if test "`$CXX -v 2>&1 | grep -c 'clang version'`" != "0"; then
-     CLANG_CXX=1
-   fi
-fi
+MOZ_TOOL_VARIABLES
 
 dnl Special win32 checks
 dnl ========================================================
@@ -3876,32 +3823,7 @@ if test -n "$JS_OOM_DO_BACKTRACES"; then
     AC_DEFINE(JS_OOM_DO_BACKTRACES)
 fi
 
-dnl ======================================================
-dnl = Enable compiling with ccache
-dnl ======================================================
-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 $CXX"
-    else
-        AC_MSG_ERROR([$CCACHE is not executable])
-    fi
-fi
+MOZ_CHECK_CCACHE
 
 dnl ========================================================
 dnl = Enable static checking using gcc-dehydra