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/evs/1.0/default/Android.mk b/automotive/evs/1.0/default/Android.mk
index 0ee7071..28abe6c 100644
--- a/automotive/evs/1.0/default/Android.mk
+++ b/automotive/evs/1.0/default/Android.mk
@@ -24,6 +24,6 @@
     liblog \
     libutils \
 
-LOCAL_CFLAGS := -O0 -g
+LOCAL_CFLAGS := -O0 -g -Wall -Werror
 
 include $(BUILD_EXECUTABLE)
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/biometrics/fingerprint/2.1/default/Android.bp b/biometrics/fingerprint/2.1/default/Android.bp
index e1d2cf7..b12ce61 100644
--- a/biometrics/fingerprint/2.1/default/Android.bp
+++ b/biometrics/fingerprint/2.1/default/Android.bp
@@ -1,5 +1,6 @@
 cc_binary {
     name: "android.hardware.biometrics.fingerprint@2.1-service",
+    defaults: ["hidl_defaults"],
     init_rc: ["android.hardware.biometrics.fingerprint@2.1-service.rc"],
     vendor: true,
     relative_install_path: "hw",
diff --git a/biometrics/fingerprint/2.1/default/service.cpp b/biometrics/fingerprint/2.1/default/service.cpp
index 1697c07..edfaac4 100644
--- a/biometrics/fingerprint/2.1/default/service.cpp
+++ b/biometrics/fingerprint/2.1/default/service.cpp
@@ -35,7 +35,9 @@
     configureRpcThreadpool(1, true /*callerWillJoin*/);
 
     if (bio != nullptr) {
-        bio->registerAsService();
+        if (::android::OK != bio->registerAsService()) {
+            return 1;
+        }
     } else {
         ALOGE("Can't create instance of BiometricsFingerprint, nullptr");
     }
diff --git a/bluetooth/1.0/default/Android.bp b/bluetooth/1.0/default/Android.bp
index 63e7562..48bbadf 100644
--- a/bluetooth/1.0/default/Android.bp
+++ b/bluetooth/1.0/default/Android.bp
@@ -115,6 +115,7 @@
 
 cc_binary {
     name: "android.hardware.bluetooth@1.0-service",
+    defaults: ["hidl_defaults"],
     relative_install_path: "hw",
     vendor: true,
     init_rc: ["android.hardware.bluetooth@1.0-service.rc"],
diff --git a/boot/1.0/default/Android.bp b/boot/1.0/default/Android.bp
index c9b7492..6cfbf32 100644
--- a/boot/1.0/default/Android.bp
+++ b/boot/1.0/default/Android.bp
@@ -1,5 +1,6 @@
 cc_library_shared {
     name: "android.hardware.boot@1.0-impl",
+    defaults: ["hidl_defaults"],
     relative_install_path: "hw",
     vendor: true,
     srcs: ["BootControl.cpp"],
@@ -17,6 +18,7 @@
 
 cc_binary {
     name: "android.hardware.boot@1.0-service",
+    defaults: ["hidl_defaults"],
     relative_install_path: "hw",
     vendor: true,
     init_rc: ["android.hardware.boot@1.0-service.rc"],
diff --git a/gatekeeper/1.0/default/Android.bp b/gatekeeper/1.0/default/Android.bp
index 4e6c9f0..ae3b91c 100644
--- a/gatekeeper/1.0/default/Android.bp
+++ b/gatekeeper/1.0/default/Android.bp
@@ -1,5 +1,6 @@
 cc_library_shared {
     name: "android.hardware.gatekeeper@1.0-impl",
+    defaults: ["hidl_defaults"],
     relative_install_path: "hw",
     vendor: true,
 
@@ -18,6 +19,7 @@
 
 cc_binary {
     name: "android.hardware.gatekeeper@1.0-service",
+    defaults: ["hidl_defaults"],
     relative_install_path: "hw",
     vendor: true,
     init_rc: ["android.hardware.gatekeeper@1.0-service.rc"],
diff --git a/gnss/1.0/default/Android.bp b/gnss/1.0/default/Android.bp
index 007ed97..ca495e6 100644
--- a/gnss/1.0/default/Android.bp
+++ b/gnss/1.0/default/Android.bp
@@ -1,5 +1,6 @@
 cc_library_shared {
     name: "android.hardware.gnss@1.0-impl",
+    defaults: ["hidl_defaults"],
     vendor: true,
     relative_install_path: "hw",
     srcs: [
@@ -27,14 +28,13 @@
         "libhardware",
     ],
 
-    cflags: ["-Werror"],
-
 }
 
 cc_binary {
     relative_install_path: "hw",
     vendor: true,
     name: "android.hardware.gnss@1.0-service",
+    defaults: ["hidl_defaults"],
     init_rc: ["android.hardware.gnss@1.0-service.rc"],
     srcs: ["service.cpp"],
 
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/soundtrigger/2.0/default/Android.mk b/soundtrigger/2.0/default/Android.mk
index 068c6b4..9262858 100644
--- a/soundtrigger/2.0/default/Android.mk
+++ b/soundtrigger/2.0/default/Android.mk
@@ -23,6 +23,8 @@
 LOCAL_SRC_FILES := \
     SoundTriggerHalImpl.cpp
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_SHARED_LIBRARIES := \
         libhidlbase \
         libhidltransport \
diff --git a/thermal/1.0/default/Android.bp b/thermal/1.0/default/Android.bp
index 2054b88..9d81474 100644
--- a/thermal/1.0/default/Android.bp
+++ b/thermal/1.0/default/Android.bp
@@ -34,6 +34,7 @@
 
 cc_binary {
     name: "android.hardware.thermal@1.0-service",
+    defaults: ["hidl_defaults"],
     relative_install_path: "hw",
     vendor: true,
     init_rc: ["android.hardware.thermal@1.0-service.rc"],
diff --git a/tv/cec/1.0/default/Android.bp b/tv/cec/1.0/default/Android.bp
index efb88ec..069f327 100644
--- a/tv/cec/1.0/default/Android.bp
+++ b/tv/cec/1.0/default/Android.bp
@@ -1,5 +1,6 @@
 cc_library_shared {
     name: "android.hardware.tv.cec@1.0-impl",
+    defaults: ["hidl_defaults"],
     vendor: true,
     relative_install_path: "hw",
     srcs: ["HdmiCec.cpp"],
@@ -18,6 +19,7 @@
 
 cc_binary {
     name: "android.hardware.tv.cec@1.0-service",
+    defaults: ["hidl_defaults"],
     relative_install_path: "hw",
     vendor: true,
     init_rc: ["android.hardware.tv.cec@1.0-service.rc"],
diff --git a/tv/input/1.0/default/Android.bp b/tv/input/1.0/default/Android.bp
index f8956f1..7c140a5 100644
--- a/tv/input/1.0/default/Android.bp
+++ b/tv/input/1.0/default/Android.bp
@@ -1,5 +1,6 @@
 cc_library_shared {
     name: "android.hardware.tv.input@1.0-impl",
+    defaults: ["hidl_defaults"],
     vendor: true,
     relative_install_path: "hw",
     srcs: ["TvInput.cpp"],
@@ -19,6 +20,7 @@
 
 cc_binary {
     name: "android.hardware.tv.input@1.0-service",
+    defaults: ["hidl_defaults"],
     relative_install_path: "hw",
     vendor: true,
     init_rc: ["android.hardware.tv.input@1.0-service.rc"],