diff --git a/tests/expression/1.0/Android.mk b/tests/expression/1.0/Android.mk
new file mode 100644
index 0000000..98dc29e
--- /dev/null
+++ b/tests/expression/1.0/Android.mk
@@ -0,0 +1,33 @@
+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := android.hardware.tests.expression@1.0
+LOCAL_MODULE_CLASS := SHARED_LIBRARIES
+
+intermediates := $(local-generated-sources-dir)
+
+HIDL := $(HOST_OUT_EXECUTABLES)/hidl-gen$(HOST_EXECUTABLE_SUFFIX)
+
+#
+# Build IExpression.hal
+#
+GEN := $(intermediates)/android/hardware/tests/expression/1.0/ExpressionAll.cpp
+$(GEN): $(HIDL)
+$(GEN): PRIVATE_HIDL := $(HIDL)
+$(GEN): PRIVATE_DEPS := $(LOCAL_PATH)/IExpression.hal
+$(GEN): PRIVATE_OUTPUT_DIR := $(intermediates)
+$(GEN): PRIVATE_CUSTOM_TOOL = \
+    $(PRIVATE_HIDL) -o $(PRIVATE_OUTPUT_DIR) \
+    -Lc++ -randroid.hardware:hardware/interfaces\
+    android.hardware.tests.expression@1.0::$(patsubst %.hal,%,$(notdir $(PRIVATE_DEPS)))
+
+$(GEN): $(LOCAL_PATH)/IExpression.hal
+	$(transform-generated-source)
+LOCAL_GENERATED_SOURCES += $(GEN)
+
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(intermediates)
+LOCAL_SHARED_LIBRARIES := \
+  libhwbinder \
+  libutils \
+
+include $(BUILD_SHARED_LIBRARY)
diff --git a/tests/expression/1.0/IExpression.hal b/tests/expression/1.0/IExpression.hal
new file mode 100644
index 0000000..8a98055
--- /dev/null
+++ b/tests/expression/1.0/IExpression.hal
@@ -0,0 +1,33 @@
+package android.hardware.tests.expression@1.0;
+
+@hal_type(type="LIGHT")
+
+interface IExpression {
+  enum int_literals : int32_t {
+    literal = 4,
+    literalL = -4L,
+    simpleArithmetic = 4 + 1,
+    simpleIdentifier = literalL,
+    simpleIdentifier2 = literalL + simpleArithmetic,
+    boolExpr = 1 == 7 && !((3 != 4 || (2 < 3 <= 3 > 4)) >= 0),
+    bitExpr = ~42 & (1 << 3 | 16 >> 2) ^ 7,
+    arithmeticExpr = 2 + 3 - 4 * -7 / (10 % 3),
+    messyExpr = 2   + (-3&4   / 7),
+    paranExpr = (((((1 + 1))))),
+    ternary = 1?2:3,
+    ternary2 = 1&&2?3:4,
+    complicatedTernary2 = 1 - 1 && 2 + 3 || 5 ? 7 * 8 : -3
+  };
+  // const float SIMPLE_FLOAT1 = 1e20;
+  // const float SIMPLE_FLOAT2 = 1e-10L;
+  // const float SIMPLE_FLOAT3 = 1.;
+  // const float SIMPLE_FLOAT4 = 1.e-2;
+  // const float SIMPLE_FLOAT5 = 3.1416;
+  // const float SIMPLE_FLOAT6 = .5f;
+  // const float SIMPLE_FLOAT7 = 0.5e-3L;
+  // struct expressionist_t {
+  //   uint8_t[1 << 10] buffer;
+  // };
+  // @param(name = "mask", normal = 1 << 5)
+  // setExpression(expressionist_t state, int32_t mask) generates (int32_t ret);
+};
diff --git a/tests/foo/1.0/Android.mk b/tests/foo/1.0/Android.mk
index 3e2794b..2356506 100644
--- a/tests/foo/1.0/Android.mk
+++ b/tests/foo/1.0/Android.mk
@@ -9,23 +9,6 @@
 HIDL := $(HOST_OUT_EXECUTABLES)/hidl-gen$(HOST_EXECUTABLE_SUFFIX)
 
 #
-# Build IFooCallback.hal
-#
-GEN := $(intermediates)/android/hardware/tests/foo/1.0/FooCallbackAll.cpp
-$(GEN): $(HIDL)
-$(GEN): PRIVATE_HIDL := $(HIDL)
-$(GEN): PRIVATE_DEPS := $(LOCAL_PATH)/IFooCallback.hal
-$(GEN): PRIVATE_OUTPUT_DIR := $(intermediates)
-$(GEN): PRIVATE_CUSTOM_TOOL = \
-    $(PRIVATE_HIDL) -o $(PRIVATE_OUTPUT_DIR) \
-    -Lc++ -randroid.hardware:hardware/interfaces\
-    android.hardware.tests.foo@1.0::$(patsubst %.hal,%,$(notdir $(PRIVATE_DEPS)))
-
-$(GEN): $(LOCAL_PATH)/IFooCallback.hal
-	$(transform-generated-source)
-LOCAL_GENERATED_SOURCES += $(GEN)
-
-#
 # Build types.hal
 #
 GEN := $(intermediates)/android/hardware/tests/foo/1.0/types.cpp
@@ -43,6 +26,23 @@
 LOCAL_GENERATED_SOURCES += $(GEN)
 
 #
+# Build IFooCallback.hal
+#
+GEN := $(intermediates)/android/hardware/tests/foo/1.0/FooCallbackAll.cpp
+$(GEN): $(HIDL)
+$(GEN): PRIVATE_HIDL := $(HIDL)
+$(GEN): PRIVATE_DEPS := $(LOCAL_PATH)/IFooCallback.hal
+$(GEN): PRIVATE_OUTPUT_DIR := $(intermediates)
+$(GEN): PRIVATE_CUSTOM_TOOL = \
+    $(PRIVATE_HIDL) -o $(PRIVATE_OUTPUT_DIR) \
+    -Lc++ -randroid.hardware:hardware/interfaces\
+    android.hardware.tests.foo@1.0::$(patsubst %.hal,%,$(notdir $(PRIVATE_DEPS)))
+
+$(GEN): $(LOCAL_PATH)/IFooCallback.hal
+	$(transform-generated-source)
+LOCAL_GENERATED_SOURCES += $(GEN)
+
+#
 # Build IFoo.hal
 #
 GEN := $(intermediates)/android/hardware/tests/foo/1.0/FooAll.cpp