diff --git a/CleanSpec.mk b/CleanSpec.mk
index 42399a6..cad545c 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -56,3 +56,4 @@
 $(call add-clean-step, rm -rf $(OUT_DIR)/soong/.intermediates/hardware/interfaces/)
 $(call add-clean-step, rm -rf $(OUT_DIR)/soong/.intermediates/hardware/interfaces/)
 $(call add-clean-step, find $(PRODUCT_OUT)/system $(PRODUCT_OUT)/vendor -type f -name "android\.hardware\.configstore*" -print0 | xargs -0 rm -f)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/lib/vndk-sp/android.hardware.graphics.allocator*)
diff --git a/audio/2.0/default/Android.mk b/audio/2.0/default/Android.mk
index 621853c..70fa750 100644
--- a/audio/2.0/default/Android.mk
+++ b/audio/2.0/default/Android.mk
@@ -30,6 +30,8 @@
     StreamIn.cpp \
     StreamOut.cpp \
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_SHARED_LIBRARIES := \
     libbase \
     libcutils \
@@ -65,6 +67,8 @@
 LOCAL_SRC_FILES := \
     service.cpp
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_SHARED_LIBRARIES := \
     libhidlbase \
     libhidltransport \
diff --git a/audio/2.0/default/StreamIn.cpp b/audio/2.0/default/StreamIn.cpp
index b81cbb9..575a4f4 100644
--- a/audio/2.0/default/StreamIn.cpp
+++ b/audio/2.0/default/StreamIn.cpp
@@ -87,7 +87,6 @@
     }
     ssize_t readResult = mStream->read(mStream, &mBuffer[0], requestedToRead);
     mStatus.retval = Result::OK;
-    uint64_t read = 0;
     if (readResult >= 0) {
         mStatus.reply.read = readResult;
         if (!mDataMQ->write(&mBuffer[0], readResult)) {
@@ -326,7 +325,7 @@
     ThreadInfo threadInfo = {0, 0};
 
     // Wrap the _hidl_cb to return an error
-    auto sendError = [this, &threadInfo, &_hidl_cb](Result result) {
+    auto sendError = [&threadInfo, &_hidl_cb](Result result) {
         _hidl_cb(result, CommandMQ::Descriptor(), DataMQ::Descriptor(),
                  StatusMQ::Descriptor(), threadInfo);
 
diff --git a/audio/2.0/default/StreamOut.cpp b/audio/2.0/default/StreamOut.cpp
index 290d0b1..242e8fc 100644
--- a/audio/2.0/default/StreamOut.cpp
+++ b/audio/2.0/default/StreamOut.cpp
@@ -302,7 +302,7 @@
     ThreadInfo threadInfo = {0, 0};
 
     // Wrap the _hidl_cb to return an error
-    auto sendError = [this, &threadInfo, &_hidl_cb](Result result) {
+    auto sendError = [&threadInfo, &_hidl_cb](Result result) {
         _hidl_cb(result, CommandMQ::Descriptor(), DataMQ::Descriptor(),
                  StatusMQ::Descriptor(), threadInfo);
 
diff --git a/audio/effect/2.0/default/Android.bp b/audio/effect/2.0/default/Android.bp
index 79bb8b0..e1072b4 100644
--- a/audio/effect/2.0/default/Android.bp
+++ b/audio/effect/2.0/default/Android.bp
@@ -1,5 +1,6 @@
 cc_library_shared {
     name: "android.hardware.audio.effect@2.0-impl",
+    defaults: ["hidl_defaults"],
     vendor: true,
     relative_install_path: "hw",
     srcs: [
diff --git a/audio/effect/2.0/default/Effect.cpp b/audio/effect/2.0/default/Effect.cpp
index 2d36604..184607e 100644
--- a/audio/effect/2.0/default/Effect.cpp
+++ b/audio/effect/2.0/default/Effect.cpp
@@ -610,10 +610,8 @@
 }
 
 Return<void> Effect::getAuxChannelsConfig(getAuxChannelsConfig_cb _hidl_cb)  {
-    uint32_t halCmd = EFFECT_FEATURE_AUX_CHANNELS;
     uint32_t halResult[alignedSizeIn<uint32_t>(sizeof(uint32_t) + sizeof(channel_config_t))];
     memset(halResult, 0, sizeof(halResult));
-    uint32_t halResultSize = 0;
     EffectAuxChannelsConfig result;
     Result retval = getCurrentConfigImpl(
             EFFECT_FEATURE_AUX_CHANNELS,
diff --git a/automotive/vehicle/2.0/default/Android.mk b/automotive/vehicle/2.0/default/Android.mk
index 72e1364..ebc565d 100644
--- a/automotive/vehicle/2.0/default/Android.mk
+++ b/automotive/vehicle/2.0/default/Android.mk
@@ -28,6 +28,8 @@
     common/src/VehiclePropertyStore.cpp \
     common/src/VehicleUtils.cpp \
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_C_INCLUDES := \
     $(LOCAL_PATH)/common/include/vhal_v2_0
 
@@ -53,6 +55,8 @@
     common/src/VehiclePropertyStore.cpp \
     common/src/VehicleUtils.cpp \
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_C_INCLUDES := \
     $(LOCAL_PATH)/common/include/vhal_v2_0
 
diff --git a/automotive/vehicle/2.1/default/Android.mk b/automotive/vehicle/2.1/default/Android.mk
index f19263c..f6efc0e 100644
--- a/automotive/vehicle/2.1/default/Android.mk
+++ b/automotive/vehicle/2.1/default/Android.mk
@@ -25,6 +25,8 @@
 LOCAL_SRC_FILES := \
     common/src/Obd2SensorStore.cpp
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_C_INCLUDES := \
     $(LOCAL_PATH)/common/include/vhal_v2_1 \
     $(LOCAL_PATH)/../../2.0/default/common/include/vhal_v2_0 \
diff --git a/graphics/allocator/2.0/Android.bp b/graphics/allocator/2.0/Android.bp
index 0b0722e..50b474e 100644
--- a/graphics/allocator/2.0/Android.bp
+++ b/graphics/allocator/2.0/Android.bp
@@ -5,7 +5,6 @@
     root: "android.hardware",
     vndk: {
         enabled: true,
-        support_system_process: true,
     },
     srcs: [
         "IAllocator.hal",
diff --git a/keymaster/3.0/vts/functional/keymaster_hidl_hal_test.cpp b/keymaster/3.0/vts/functional/keymaster_hidl_hal_test.cpp
index 78353ea..9e7c9f6 100644
--- a/keymaster/3.0/vts/functional/keymaster_hidl_hal_test.cpp
+++ b/keymaster/3.0/vts/functional/keymaster_hidl_hal_test.cpp
@@ -2762,7 +2762,8 @@
               Begin(KeyPurpose::ENCRYPT,
                     AuthorizationSetBuilder().Padding(PaddingMode::RSA_OAEP).Digest(Digest::SHA1)));
     string result;
-    EXPECT_EQ(ErrorCode::INVALID_INPUT_LENGTH, Finish(message, &result));
+    auto error = Finish(message, &result);
+    EXPECT_TRUE(error == ErrorCode::INVALID_INPUT_LENGTH || error == ErrorCode::INVALID_ARGUMENT);
     EXPECT_EQ(0U, result.size());
 }
 
@@ -2820,7 +2821,8 @@
     auto params = AuthorizationSetBuilder().Padding(PaddingMode::RSA_PKCS1_1_5_ENCRYPT);
     EXPECT_EQ(ErrorCode::OK, Begin(KeyPurpose::ENCRYPT, params));
     string result;
-    EXPECT_EQ(ErrorCode::INVALID_INPUT_LENGTH, Finish(message, &result));
+    auto error = Finish(message, &result);
+    EXPECT_TRUE(error == ErrorCode::INVALID_INPUT_LENGTH || error == ErrorCode::INVALID_ARGUMENT);
     EXPECT_EQ(0U, result.size());
 }
 
diff --git a/light/2.0/default/Android.mk b/light/2.0/default/Android.mk
index 1f44e66..da75e1a 100644
--- a/light/2.0/default/Android.mk
+++ b/light/2.0/default/Android.mk
@@ -7,6 +7,8 @@
 LOCAL_SRC_FILES := \
     Light.cpp \
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_SHARED_LIBRARIES := \
     libhidlbase \
     libhidltransport \
@@ -28,6 +30,8 @@
 LOCAL_SRC_FILES := \
     service.cpp \
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_SHARED_LIBRARIES := \
     liblog \
     libcutils \
diff --git a/tests/expression/1.0/IExpressionExt.hal b/tests/expression/1.0/IExpressionExt.hal
index e96bf0d..8b56ec6 100644
--- a/tests/expression/1.0/IExpressionExt.hal
+++ b/tests/expression/1.0/IExpressionExt.hal
@@ -26,7 +26,9 @@
         ENUM_BEST = android.hardware.tests.expression@1.0::IExpression.Constants:CONST_BAR,
     };
 
-    typedef Color[((Constants:MAX_ARRAY_SIZE << 1) - (Constants:CONST_FOO + 1)*8) >> 1] SixteenColors;
+    typedef Constants AlsoConstants;
+
+    typedef Color[((Constants:MAX_ARRAY_SIZE << 1) - (AlsoConstants:CONST_FOO + 1)*8) >> 1] SixteenColors;
     struct ArrayOfColors {
         Color[(Constants:MAX_ARRAY_SIZE << 1) - (Constants:CONST_FOO + 1)*8] my32Colors; // 32
     };
diff --git a/tests/foo/1.0/types.hal b/tests/foo/1.0/types.hal
index 6b4b697..b358a93 100644
--- a/tests/foo/1.0/types.hal
+++ b/tests/foo/1.0/types.hal
@@ -38,3 +38,30 @@
 struct Unrelated {
     Outer.Inner great;
 };
+
+// structs to test enum iterators in hidl_test
+struct EnumIterators {
+    enum Empty : uint32_t {};
+
+    enum Parent : uint32_t {
+        A,
+    };
+    enum EmptyChild : Parent {};
+    enum Grandchild : EmptyChild {
+        B,
+    };
+
+    enum SkipsValues : uint32_t {
+        A = 7,
+        B,
+        C = 100,
+        D,
+        E
+    };
+    enum MultipleValues : uint32_t {
+        A = 7,
+        B = 7,
+        C = 8,
+        D = 7,
+    };
+};
\ No newline at end of file
diff --git a/usb/1.0/vts/functional/VtsHalUsbV1_0TargetTest.cpp b/usb/1.0/vts/functional/VtsHalUsbV1_0TargetTest.cpp
index b77398f..e01b974 100644
--- a/usb/1.0/vts/functional/VtsHalUsbV1_0TargetTest.cpp
+++ b/usb/1.0/vts/functional/VtsHalUsbV1_0TargetTest.cpp
@@ -160,7 +160,7 @@
   // and the callback thread.
   std::mutex usb_mtx;
   std::condition_variable usb_cv;
-  int usb_count;
+  int usb_count = 0;
 };
 
 /*