Bug 1022349 - Part 2: Use clang-cl when building libffi if we're building with clang-cl; r=glandium

build/autoconf/ffi.m4

@@ -46,23 +46,26 @@ if test -z "$BUILDING_JS" -o -n "$JS_STANDALONE"; then
       # autotools can't quite handle an MSVC build environment yet.
       LDFLAGS=
       CFLAGS=
-      ac_configure_args="$ac_configure_args LD=link CPP=\"cl -nologo -EP\" \
-                         CXXCPP=\"cl -nologo -EP\" SHELL=sh.exe"
-      rtl=
-      if test -z "$MOZ_NO_DEBUG_RTL" -a -n "$MOZ_DEBUG"; then
-        rtl=" -DUSE_DEBUG_RTL"
+      ac_configure_args="$ac_configure_args LD=link CPP=\"$CC -nologo -EP\" \
+                         CXXCPP=\"$CXX -nologo -EP\" SHELL=sh.exe"
+      flags=
+      if test -z "$MOZ_NO_DEBUG_flags" -a -n "$MOZ_DEBUG"; then
+        flags=" -DUSE_DEBUG_RTL"
+      fi
+      if test -n "$CLANG_CL"; then
+        flags="$flags -clang-cl"
       fi
       case "${target_cpu}" in
       x86_64)
         # Need target since MSYS tools into mozilla-build may be 32bit
         ac_configure_args="$ac_configure_args \
-                           CC=\"$_topsrcdir/js/src/ctypes/libffi/msvcc.sh -m64$rtl\" \
-                           CXX=\"$_topsrcdir/js/src/ctypes/libffi/msvcc.sh -m64$rtl\""
+                           CC=\"$_topsrcdir/js/src/ctypes/libffi/msvcc.sh -m64$flags\" \
+                           CXX=\"$_topsrcdir/js/src/ctypes/libffi/msvcc.sh -m64$flags\""
         ;;
       *)
         ac_configure_args="$ac_configure_args \
-                           CC=\"$_topsrcdir/js/src/ctypes/libffi/msvcc.sh$rtl\" \
-                           CXX=\"$_topsrcdir/js/src/ctypes/libffi/msvcc.sh$rtl\""
+                           CC=\"$_topsrcdir/js/src/ctypes/libffi/msvcc.sh$flags\" \
+                           CXX=\"$_topsrcdir/js/src/ctypes/libffi/msvcc.sh$flags\""
         ;;
       esac
     fi