Use -Werror in system/extras

* Remove unused variables.
* Fix redefined macro warnings.
* Fix sign-compare warnings.
* Fix 'return false' in main().
* Keep existing warnings to fix later.

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ib92ef5297693595fb84ed4f8e61665bda4cee312

57 files changed, 121 insertions, 98 deletions

diff --git a/ANRdaemon/Android.mk b/ANRdaemon/Android.mk
index 24072e21..de5accec 100644
--- a/ANRdaemon/Android.mk
+++ b/ANRdaemon/Android.mk
@@ -6,6 +6,7 @@ include $(CLEAR_VARS)
 LOCAL_SRC_FILES := ANRdaemon.cpp
 LOCAL_C_INCLUDES += external/zlib
 LOCAL_MODULE := anrd
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := debug
 LOCAL_SHARED_LIBRARIES := \
diff --git a/app-launcher/Android.mk b/app-launcher/Android.mk
index 755b1d3f..cef9daaa 100644
--- a/app-launcher/Android.mk
+++ b/app-launcher/Android.mk
@@ -5,6 +5,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE_HOST_OS := linux
 LOCAL_SRC_FILES := computestatsf.c
 LOCAL_MODULE := computestatsf
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE_TAGS := debug
 include $(BUILD_HOST_EXECUTABLE)
 
@@ -13,6 +14,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE_HOST_OS := linux
 LOCAL_SRC_FILES := computestats.c
 LOCAL_MODULE := computestats
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE_TAGS := debug
 include $(BUILD_HOST_EXECUTABLE)
 
diff --git a/boot_control_copy/Android.mk b/boot_control_copy/Android.mk
index fecd314c..c90fd7ce 100644
--- a/boot_control_copy/Android.mk
+++ b/boot_control_copy/Android.mk
@@ -4,7 +4,7 @@ LOCAL_PATH := $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := boot_control_copy.cpp bootinfo.cpp
-LOCAL_CFLAGS := -Wall -Wno-missing-field-initializers -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-missing-field-initializers -Wno-unused-parameter
 LOCAL_C_INCLUDES := system/core/mkbootimg bootable/recovery
 LOCAL_SHARED_LIBRARIES := libbase libcutils
 LOCAL_STATIC_LIBRARIES := libfs_mgr
diff --git a/bootctl/Android.mk b/bootctl/Android.mk
index 04dbf8dd..7a0c526b 100644
--- a/bootctl/Android.mk
+++ b/bootctl/Android.mk
@@ -5,6 +5,7 @@ include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := bootctl.cpp
 LOCAL_MODULE := bootctl
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES := \
     libhidlbase \
     libhidltransport \
diff --git a/bootctl/bootctl.cpp b/bootctl/bootctl.cpp
index d80bb158..799d0666 100644
--- a/bootctl/bootctl.cpp
+++ b/bootctl/bootctl.cpp
@@ -174,7 +174,6 @@ static uint32_t parse_slot(int pos, int argc, char *argv[])
 int main(int argc, char *argv[])
 {
     sp<IBootControl> module;
-    int ret;
 
     if (argc < 2) {
         usage(stderr, argc, argv);
diff --git a/cpustats/Android.mk b/cpustats/Android.mk
index 27899894..a6db30ff 100644
--- a/cpustats/Android.mk
+++ b/cpustats/Android.mk
@@ -2,6 +2,7 @@ LOCAL_PATH := $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := cpustats.c
+LOCAL_CFLAGS := -Wall -Werror
 
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := debug
diff --git a/cpustats/cpustats.c b/cpustats/cpustats.c
index 375143b6..b2b7c07c 100644
--- a/cpustats/cpustats.c
+++ b/cpustats/cpustats.c
@@ -301,7 +301,7 @@ static long unsigned get_cpu_total_time(struct cpu_info *cpu) {
  */
 static void print_stats() {
     char label[8];
-    int i, j;
+    int i;
     char print_freq;
 
     print_freq = should_print_freq_stats();
diff --git a/crypto-perf/Android.mk b/crypto-perf/Android.mk
index 291aca12..4a3cbe41 100644
--- a/crypto-perf/Android.mk
+++ b/crypto-perf/Android.mk
@@ -2,7 +2,7 @@ LOCAL_PATH := $(call my-dir)
 ifeq ($(TARGET_ARCH),arm64)
 include $(CLEAR_VARS)
 
-LOCAL_CFLAGS := -O0 -march=armv8-a+crypto
+LOCAL_CFLAGS := -O0 -march=armv8-a+crypto -Wall -Werror
 LOCAL_SRC_FILES := crypto.cpp
 
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
diff --git a/crypto-perf/crypto.cpp b/crypto-perf/crypto.cpp
index 2cd2709f..c1860764 100644
--- a/crypto-perf/crypto.cpp
+++ b/crypto-perf/crypto.cpp
@@ -121,7 +121,7 @@ int main(int argc, char **argv) {
     CPU_SET(cmd_data.cpu_to_lock, &cpuset);
     if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
 	perror("sched_setaffinity failed");
-	return false;
+	return 1;
     }
     gettimeofday(&begin_time, NULL);
     while (count < MAX_COUNT) {
diff --git a/ext4_utils/Android.mk b/ext4_utils/Android.mk
index a80e473d..6f26dd64 100644
--- a/ext4_utils/Android.mk
+++ b/ext4_utils/Android.mk
@@ -21,6 +21,7 @@ LOCAL_SHARED_LIBRARIES_darwin += libselinux
 LOCAL_SHARED_LIBRARIES_linux += libselinux
 LOCAL_CFLAGS_darwin := -DHOST
 LOCAL_CFLAGS_linux := -DHOST
+LOCAL_CFLAGS += -Wall -Werror
 include $(BUILD_HOST_EXECUTABLE)
 
 
@@ -30,6 +31,7 @@ LOCAL_MODULE := blk_alloc_to_base_fs
 LOCAL_SHARED_LIBRARIES := libcutils
 LOCAL_CFLAGS_darwin := -DHOST
 LOCAL_CFLAGS_linux := -DHOST
+LOCAL_CFLAGS += -Wall -Werror
 include $(BUILD_HOST_EXECUTABLE)
 
 #
@@ -49,7 +51,7 @@ LOCAL_SHARED_LIBRARIES := \
     libext4_utils \
     libselinux \
     libz
-LOCAL_CFLAGS := -DREAL_UUID
+LOCAL_CFLAGS := -DREAL_UUID -Wall -Werror
 include $(BUILD_EXECUTABLE)
 
 
@@ -57,11 +59,13 @@ include $(CLEAR_VARS)
 LOCAL_SRC_FILES := setup_fs.c
 LOCAL_MODULE := setup_fs
 LOCAL_SHARED_LIBRARIES += libcutils
+LOCAL_CFLAGS := -Wall -Werror
 include $(BUILD_EXECUTABLE)
 
 
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := ext4fixup_main.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE := ext4fixup
 LOCAL_SHARED_LIBRARIES += \
     libext4_utils \
@@ -72,6 +76,7 @@ include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := ext4fixup_main.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE := ext4fixup
 LOCAL_STATIC_LIBRARIES += \
     libext4_utils \
diff --git a/kexec_tools/Android.mk b/kexec_tools/Android.mk
index f6bf7dc2..c8a49321 100644
--- a/kexec_tools/Android.mk
+++ b/kexec_tools/Android.mk
@@ -20,4 +20,5 @@ LOCAL_MODULE := kexecload
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := eng
 LOCAL_SRC_FILES := kexecload.c
+LOCAL_CFLAGS := -Wall -Werror
 include $(BUILD_EXECUTABLE)
diff --git a/kexec_tools/kexecload.c b/kexec_tools/kexecload.c
index 2bf3d183..71365435 100644
--- a/kexec_tools/kexecload.c
+++ b/kexec_tools/kexecload.c
@@ -68,8 +68,7 @@ int main(int argc, char *argv[])
     int atag_file,
         zimage_file;
     int atag_size,
-        zimage_size,
-        total_size;
+        zimage_size;
     void *atag_buffer;
     void *zimage_buffer;
     struct kexec_segment segment[2];
@@ -85,7 +84,6 @@ int main(int argc, char *argv[])
     };
 
     while (1) {
-        int option_index = 0;
         c = getopt_long(argc, argv, "s:th", longopts, NULL);
         if (c < 0) {
             break;
diff --git a/ksmutils/Android.mk b/ksmutils/Android.mk
index b7825c4e..2be4ddf2 100644
--- a/ksmutils/Android.mk
+++ b/ksmutils/Android.mk
@@ -16,6 +16,7 @@ LOCAL_PATH:= $(call my-dir)
 
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := ksminfo.c lookup3.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES := libpagemap
 LOCAL_MODULE := ksminfo
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
diff --git a/ksmutils/lookup3.c b/ksmutils/lookup3.c
index 8fcc3255..6563feb3 100644
--- a/ksmutils/lookup3.c
+++ b/ksmutils/lookup3.c
@@ -316,6 +316,7 @@ uint32_t hashlittle( const void *key, size_t length, uint32_t initval)
      */
 #ifndef VALGRIND
 
+    (void) k8; // unused
     switch(length)
     {
     case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
@@ -501,6 +502,7 @@ void hashlittle2(
      */
 #ifndef VALGRIND
 
+    (void) k8; // unused
     switch(length)
     {
     case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
@@ -678,6 +680,7 @@ uint32_t hashbig( const void *key, size_t length, uint32_t initval)
      */
 #ifndef VALGRIND
 
+    (void) k8; // unused
     switch(length)
     {
     case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
diff --git a/latencytop/Android.mk b/latencytop/Android.mk
index 220f4e36..6649a83b 100644
--- a/latencytop/Android.mk
+++ b/latencytop/Android.mk
@@ -23,6 +23,6 @@ LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 
 LOCAL_MODULE_TAGS := debug
 
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 
 include $(BUILD_EXECUTABLE)
diff --git a/latencytop/latencytop.c b/latencytop/latencytop.c
index 667fbf7e..d20bd7f5 100644
--- a/latencytop/latencytop.c
+++ b/latencytop/latencytop.c
@@ -46,11 +46,9 @@ static struct latency_entry *read_process_stats(struct latency_entry *list, int
 static struct latency_entry *read_thread_stats(struct latency_entry *list, int erase, int pid, int tid, int fatal);
 
 static struct latency_entry *alloc_latency_entry(void);
-static void free_latency_entry(struct latency_entry *e);
 
 static void set_latencytop(int on);
 static struct latency_entry *read_latency_file(FILE *f, struct latency_entry *list);
-static void erase_latency_file(FILE *f);
 
 static struct latency_entry *find_latency_entry(struct latency_entry *e, char *reason);
 static void print_latency_entries(struct latency_entry *head);
@@ -286,11 +284,6 @@ static struct latency_entry *alloc_latency_entry(void) {
     return e;
 }
 
-static void free_latency_entry(struct latency_entry *e) {
-    e->next = free_entries;
-    free_entries = e;
-}
-
 static struct latency_entry *find_latency_entry(struct latency_entry *head, char *reason) {
     struct latency_entry *e;
 
@@ -319,10 +312,6 @@ static void set_latencytop(int on) {
     fclose(f);
 }
 
-static void erase_latency_file(FILE *f) {
-    fprintf(f, "erase\n");
-}
-
 static struct latency_entry *read_latency_file(FILE *f, struct latency_entry *list) {
     struct latency_entry *e, *head;
     char line[MAX_LINE];
diff --git a/librank/Android.mk b/librank/Android.mk
index 101b94a2..d19b2a6a 100644
--- a/librank/Android.mk
+++ b/librank/Android.mk
@@ -16,6 +16,7 @@ LOCAL_PATH:= $(call my-dir)
 
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := librank.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES := libpagemap
 LOCAL_MODULE := librank
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
diff --git a/librank/librank.c b/librank/librank.c
index f017c9d2..7aa19881 100644
--- a/librank/librank.c
+++ b/librank/librank.c
@@ -196,7 +196,6 @@ static int parse_perm(const char *perm)
 }
 
 int main(int argc, char *argv[]) {
-    char cmdline[256];
     char *prefix;
     size_t prefix_len;
     int (*compfn)(const void *a, const void *b);
@@ -211,8 +210,8 @@ int main(int argc, char *argv[]) {
     size_t num_maps;
     pm_memusage_t map_usage;
 
-    struct library_info *li, **lis;
-    struct mapping_info *mi, **mis;
+    struct library_info *li;
+    struct mapping_info *mi;
     struct process_info *pi;
 
     size_t i, j;
diff --git a/memtrack/Android.mk b/memtrack/Android.mk
index 5fa9f157..cd99b6cc 100644
--- a/memtrack/Android.mk
+++ b/memtrack/Android.mk
@@ -24,6 +24,7 @@ LOCAL_SRC_FILES := $(src_files)
 
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE := memtrack_share
+LOCAL_CFLAGS := -Wall -Werror -Wno-error=unused-value
 
 LOCAL_C_INCLUDES += $(includes)
 LOCAL_SHARED_LIBRARIES := \
@@ -37,6 +38,7 @@ LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 LOCAL_SRC_FILES := $(src_files)
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE := memtrack
+LOCAL_CFLAGS := -Wall -Werror -Wno-error=unused-value
 
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 LOCAL_STATIC_LIBRARIES := \
diff --git a/memtrack/memtrack.cpp b/memtrack/memtrack.cpp
index 8ff5c07d..d3736091 100644
--- a/memtrack/memtrack.cpp
+++ b/memtrack/memtrack.cpp
@@ -68,7 +68,7 @@ bool FileData::isAvail(size_t bytes_needed) {
   while (cur_idx_ + bytes_needed >= len_) {
     bytes = read(fd_, data_ + len_, max_ - len_);
     if (bytes == 0 || bytes == -1) {
-      read_complete_;
+      read_complete_; // unused read?
       break;
     }
     len_ += bytes;
diff --git a/memtrack/memtrack.h b/memtrack/memtrack.h
index 602fdb22..6c3ab453 100644
--- a/memtrack/memtrack.h
+++ b/memtrack/memtrack.h
@@ -24,7 +24,9 @@
 #include <vector>
 
 #define DEFAULT_SLEEP_DELAY_SECONDS 5
-#define NS_PER_SEC 1000000000LL
+#ifndef NS_PER_SEC
+#define NS_PER_SEC 1000000000ULL
+#endif
 
 class FileData {
 public:
diff --git a/micro_bench/Android.mk b/micro_bench/Android.mk
index 0655536e..843a2e5e 100644
--- a/micro_bench/Android.mk
+++ b/micro_bench/Android.mk
@@ -6,6 +6,7 @@ LOCAL_SRC_FILES := micro_bench.cpp
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE := micro_bench
+LOCAL_CFLAGS := -Wall -Werror -Wno-error=unused-variable
 
 LOCAL_MULTILIB := both
 LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)
@@ -19,6 +20,7 @@ LOCAL_SRC_FILES := micro_bench.cpp
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE := micro_bench_static
+LOCAL_CFLAGS := -Wall -Werror -Wno-error=unused-variable
 LOCAL_STATIC_LIBRARIES = libc libm
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 
diff --git a/micro_bench/micro_bench.cpp b/micro_bench/micro_bench.cpp
index 4d3177da..05cc54ed 100644
--- a/micro_bench/micro_bench.cpp
+++ b/micro_bench/micro_bench.cpp
@@ -400,6 +400,7 @@ int benchmarkMemset(const char *name, const command_data_t &cmd_data, void_func_
 int benchmarkMemsetCold(const char *name, const command_data_t &cmd_data, void_func_t func) {
     memset_func_t memset_func = reinterpret_cast<memset_func_t>(func);
     COLD_ONE_BUF(name, cmd_data, ;, memset_func(buf, l, size));
+    (void)buffer_size;
 
     return 0;
 }
@@ -430,7 +431,7 @@ int benchmarkMemmoveBackwards(const char *name, const command_data_t &cmd_data,
     memcpy_func_t memmove_func = reinterpret_cast<memcpy_func_t>(func);
 
     size_t size = cmd_data.args[0];
-    size_t alloc_size = size * 2 + 3 * cmd_data.dst_align;
+    size_t alloc_size = size * 2 + 3 * cmd_data.dst_align; // should alloc_size be used?
     uint8_t* src = allocateAlignedMemory(size, cmd_data.src_align, cmd_data.src_or_mask);
     if (!src)
         return -1;
diff --git a/multinetwork/Android.mk b/multinetwork/Android.mk
index 356a46a6..7e6426a1 100644
--- a/multinetwork/Android.mk
+++ b/multinetwork/Android.mk
@@ -6,6 +6,7 @@ ifneq ($(TARGET_BUILD_PDK), true)
 # Sample util binaries.
 include $(CLEAR_VARS)
 LOCAL_MODULE := dnschk
+LOCAL_CFLAGS := -Wall -Werror
 
 LOCAL_C_INCLUDES += frameworks/native/include external/libcxx/include
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
@@ -18,6 +19,7 @@ include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := httpurl
+LOCAL_CFLAGS := -Wall -Werror
 
 LOCAL_C_INCLUDES += frameworks/native/include external/libcxx/include
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
diff --git a/pagecache/Android.mk b/pagecache/Android.mk
index fe064100..7861273a 100644
--- a/pagecache/Android.mk
+++ b/pagecache/Android.mk
@@ -4,6 +4,7 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= dumpcache.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES := libcutils
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := debug
diff --git a/procmem/Android.mk b/procmem/Android.mk
index b7fba563..6e9e2105 100644
--- a/procmem/Android.mk
+++ b/procmem/Android.mk
@@ -16,6 +16,7 @@ LOCAL_PATH:= $(call my-dir)
 
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := procmem.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES := libpagemap
 LOCAL_MODULE := procmem
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
diff --git a/puncture_fs/Android.mk b/puncture_fs/Android.mk
index 0b79cca7..2c72ed8a 100644
--- a/puncture_fs/Android.mk
+++ b/puncture_fs/Android.mk
@@ -17,6 +17,7 @@ LOCAL_PATH := $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := puncture_fs.c
+LOCAL_CFLAGS := -Wall -Werror
 
 LOCAL_C_INCLUDES += system/core/logwrapper/include
 
diff --git a/sane_schedstat/Android.mk b/sane_schedstat/Android.mk
index c984b9f2..5351ea6a 100644
--- a/sane_schedstat/Android.mk
+++ b/sane_schedstat/Android.mk
@@ -7,6 +7,6 @@ LOCAL_SRC_FILES := sane_schedstat.c
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE := sane_schedstat
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 
 include $(BUILD_EXECUTABLE)
diff --git a/showmap/Android.mk b/showmap/Android.mk
index 44ca8183..c9279ba1 100644
--- a/showmap/Android.mk
+++ b/showmap/Android.mk
@@ -4,6 +4,7 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= showmap.cpp
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE:= showmap
diff --git a/showslab/Android.mk b/showslab/Android.mk
index c914a8b6..f48c52cb 100644
--- a/showslab/Android.mk
+++ b/showslab/Android.mk
@@ -4,6 +4,7 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= showslab.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES :=
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 
diff --git a/simpleperf/Android.mk b/simpleperf/Android.mk
index 5d079761..3cc6cf9f 100644
--- a/simpleperf/Android.mk
+++ b/simpleperf/Android.mk
@@ -17,17 +17,17 @@ LOCAL_PATH := $(call my-dir)
 
 simpleperf_version :=  $(shell git -C $(LOCAL_PATH) rev-parse --short=12 HEAD 2>/dev/null)
 
-simpleperf_common_cppflags := -Wextra -Wunused -Wno-unknown-pragmas \
+simpleperf_common_cflags := -Wall -Werror -Wextra -Wunused -Wno-unknown-pragmas \
                               -DSIMPLEPERF_REVISION='"$(simpleperf_version)"'
 
-simpleperf_cppflags_target := $(simpleperf_common_cppflags)
+simpleperf_cflags_target := $(simpleperf_common_cflags)
 
-simpleperf_cppflags_host := $(simpleperf_common_cppflags) \
+simpleperf_cflags_host := $(simpleperf_common_cflags) \
                             -DUSE_BIONIC_UAPI_HEADERS -I bionic/libc/kernel \
                             -fvisibility=hidden \
 
-simpleperf_cppflags_host_darwin := -I $(LOCAL_PATH)/nonlinux_support/include
-simpleperf_cppflags_host_windows := -I $(LOCAL_PATH)/nonlinux_support/include
+simpleperf_cflags_host_darwin := -I $(LOCAL_PATH)/nonlinux_support/include
+simpleperf_cflags_host_windows := -I $(LOCAL_PATH)/nonlinux_support/include
 
 
 LLVM_ROOT_PATH := external/llvm
@@ -133,7 +133,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target)
+LOCAL_CFLAGS := $(simpleperf_cflags_target)
 LOCAL_SRC_FILES := \
   $(libsimpleperf_src_files) \
   $(libsimpleperf_src_files_linux) \
@@ -148,10 +148,10 @@ include $(BUILD_STATIC_LIBRARY)
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf
 LOCAL_MODULE_HOST_OS := darwin linux windows
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_darwin := $(simpleperf_cppflags_host_darwin)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
-LOCAL_CPPFLAGS_windows := $(simpleperf_cppflags_host_windows)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_darwin := $(simpleperf_cflags_host_darwin)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
+LOCAL_CFLAGS_windows := $(simpleperf_cflags_host_windows)
 LOCAL_SRC_FILES := $(libsimpleperf_src_files)
 LOCAL_SRC_FILES_darwin := $(libsimpleperf_src_files_darwin)
 LOCAL_SRC_FILES_linux := $(libsimpleperf_src_files_linux)
@@ -174,7 +174,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE := simpleperf
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target)
+LOCAL_CFLAGS := $(simpleperf_cflags_target)
 LOCAL_SRC_FILES := main.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_with_libc_target)
 ifdef TARGET_2ND_ARCH
@@ -195,10 +195,10 @@ endif
 include $(CLEAR_VARS)
 LOCAL_MODULE := simpleperf_host
 LOCAL_MODULE_HOST_OS := darwin linux windows
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_darwin := $(simpleperf_cppflags_host_darwin)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
-LOCAL_CPPFLAGS_windows := $(simpleperf_cppflags_host_windows)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_darwin := $(simpleperf_cflags_host_darwin)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
+LOCAL_CFLAGS_windows := $(simpleperf_cflags_host_windows)
 LOCAL_SRC_FILES := main.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_host)
 LOCAL_STATIC_LIBRARIES_linux := $(simpleperf_static_libraries_host_linux)
@@ -227,7 +227,7 @@ endif
 # libsimpleperf_record.a on target
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_record
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target)
+LOCAL_CFLAGS := $(simpleperf_cflags_target)
 LOCAL_SRC_FILES := record_lib_interface.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_target)
 LOCAL_MULTILIB := both
@@ -240,7 +240,7 @@ include $(BUILD_STATIC_LIBRARY)
 # libsimpleperf_record.so on target
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_record
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target)
+LOCAL_CFLAGS := $(simpleperf_cflags_target)
 LOCAL_SRC_FILES := record_lib_interface.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_target)
 LOCAL_MULTILIB := both
@@ -254,8 +254,8 @@ include $(BUILD_SHARED_LIBRARY)
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_record
 LOCAL_MODULE_HOST_OS := linux
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
 LOCAL_SRC_FILES := record_lib_interface.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_host)
 LOCAL_STATIC_LIBRARIES_linux := $(simpleperf_static_libraries_host_linux)
@@ -270,8 +270,8 @@ include $(BUILD_HOST_STATIC_LIBRARY)
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_record
 LOCAL_MODULE_HOST_OS := linux
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
 LOCAL_SRC_FILES := record_lib_interface.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_host)
 LOCAL_STATIC_LIBRARIES_linux := $(simpleperf_static_libraries_host_linux)
@@ -290,10 +290,10 @@ include $(BUILD_HOST_SHARED_LIBRARY)
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_report
 LOCAL_MODULE_HOST_OS := darwin linux windows
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_darwin := $(simpleperf_cppflags_host_darwin)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
-LOCAL_CPPFLAGS_windows := $(simpleperf_cppflags_host_windows)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_darwin := $(simpleperf_cflags_host_darwin)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
+LOCAL_CFLAGS_windows := $(simpleperf_cflags_host_windows)
 LOCAL_SRC_FILES := report_lib_interface.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_host)
 LOCAL_STATIC_LIBRARIES_linux := $(simpleperf_static_libraries_host_linux)
@@ -321,7 +321,7 @@ endif
 # libsimpleperf_inplace_sampler.so on target
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_inplace_sampler
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target)
+LOCAL_CFLAGS := $(simpleperf_cflags_target)
 LOCAL_SRC_FILES := inplace_sampler_lib.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_target)
 LOCAL_MULTILIB := both
@@ -334,8 +334,8 @@ include $(BUILD_SHARED_LIBRARY)
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_inplace_sampler
 LOCAL_MODULE_HOST_OS := linux
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
 LOCAL_SRC_FILES := inplace_sampler_lib.cpp
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_host)
 LOCAL_STATIC_LIBRARIES_linux := $(simpleperf_static_libraries_host_linux)
@@ -375,7 +375,7 @@ simpleperf_unit_test_src_files_linux := \
 include $(CLEAR_VARS)
 LOCAL_MODULE := simpleperf_unit_test
 LOCAL_COMPATIBILITY_SUITE := device-tests
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target)
+LOCAL_CFLAGS := $(simpleperf_cflags_target)
 LOCAL_SRC_FILES := \
   $(simpleperf_unit_test_src_files) \
   $(simpleperf_unit_test_src_files_linux) \
@@ -391,10 +391,10 @@ include $(BUILD_NATIVE_TEST)
 include $(CLEAR_VARS)
 LOCAL_MODULE := simpleperf_unit_test
 LOCAL_MODULE_HOST_OS := darwin linux windows
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_darwin := $(simpleperf_cppflags_host_darwin)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
-LOCAL_CPPFLAGS_windows := $(simpleperf_cppflags_host_windows)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_darwin := $(simpleperf_cflags_host_darwin)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
+LOCAL_CFLAGS_windows := $(simpleperf_cflags_host_windows)
 LOCAL_SRC_FILES := $(simpleperf_unit_test_src_files)
 LOCAL_SRC_FILES_linux := $(simpleperf_unit_test_src_files_linux)
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_host)
@@ -414,7 +414,7 @@ simpleperf_cpu_hotplug_test_src_files := \
 include $(CLEAR_VARS)
 LOCAL_MODULE := simpleperf_cpu_hotplug_test
 LOCAL_COMPATIBILITY_SUITE := device-tests
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target)
+LOCAL_CFLAGS := $(simpleperf_cflags_target)
 LOCAL_SRC_FILES := $(simpleperf_cpu_hotplug_test_src_files)
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_with_libc_target)
 LOCAL_MULTILIB := both
@@ -426,8 +426,8 @@ include $(BUILD_NATIVE_TEST)
 include $(CLEAR_VARS)
 LOCAL_MODULE := simpleperf_cpu_hotplug_test
 LOCAL_MODULE_HOST_OS := linux
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
 LOCAL_SRC_FILES := $(simpleperf_cpu_hotplug_test_src_files)
 LOCAL_STATIC_LIBRARIES := libsimpleperf $(simpleperf_static_libraries_host)
 LOCAL_STATIC_LIBRARIES_linux := $(simpleperf_static_libraries_host_linux)
@@ -448,7 +448,7 @@ libsimpleperf_cts_test_src_files := \
 # libsimpleperf_cts_test target
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_cts_test
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target) -DRUN_IN_APP_CONTEXT="\"com.android.simpleperf\""
+LOCAL_CFLAGS := $(simpleperf_cflags_target) -DRUN_IN_APP_CONTEXT="\"com.android.simpleperf\""
 LOCAL_SRC_FILES := $(libsimpleperf_cts_test_src_files)
 LOCAL_STATIC_LIBRARIES := $(simpleperf_static_libraries_target)
 LOCAL_MULTILIB := both
@@ -460,8 +460,8 @@ include $(BUILD_STATIC_TEST_LIBRARY)
 include $(CLEAR_VARS)
 LOCAL_MODULE := libsimpleperf_cts_test
 LOCAL_MODULE_HOST_OS := linux
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
 LOCAL_SRC_FILES := $(libsimpleperf_cts_test_src_files)
 LOCAL_STATIC_LIBRARIES := $(simpleperf_static_libraries_host)
 LOCAL_STATIC_LIBRARIES_linux := $(simpleperf_static_libraries_host_linux)
@@ -476,7 +476,7 @@ include $(BUILD_HOST_STATIC_TEST_LIBRARY)
 # simpleperf_record_test target
 include $(CLEAR_VARS)
 LOCAL_MODULE := simpleperf_record_test
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_target)
+LOCAL_CFLAGS := $(simpleperf_cflags_target)
 LOCAL_SRC_FILES := record_lib_test.cpp
 LOCAL_SHARED_LIBRARIES := libsimpleperf_record
 LOCAL_MULTILIB := both
@@ -486,8 +486,8 @@ include $(BUILD_NATIVE_TEST)
 include $(CLEAR_VARS)
 LOCAL_MODULE := simpleperf_record_test
 LOCAL_MODULE_HOST_OS := linux
-LOCAL_CPPFLAGS := $(simpleperf_cppflags_host)
-LOCAL_CPPFLAGS_linux := $(simpleperf_cppflags_host_linux)
+LOCAL_CFLAGS := $(simpleperf_cflags_host)
+LOCAL_CFLAGS_linux := $(simpleperf_cflags_host_linux)
 LOCAL_SRC_FILES := record_lib_test.cpp
 LOCAL_SHARED_LIBRARIES := libsimpleperf_record
 LOCAL_LDLIBS_linux := $(simpleperf_ldlibs_host_linux)
diff --git a/sound/Android.mk b/sound/Android.mk
index a08c4371..860c4958 100644
--- a/sound/Android.mk
+++ b/sound/Android.mk
@@ -3,6 +3,6 @@ LOCAL_PATH := $(call my-dir)
 include $(CLEAR_VARS)
 LOCAL_MODULE := sound
 LOCAL_SRC_FILES := playwav.c
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 include $(BUILD_EXECUTABLE)
 
diff --git a/sound/playwav.c b/sound/playwav.c
index 19a755e8..604ad959 100644
--- a/sound/playwav.c
+++ b/sound/playwav.c
@@ -40,7 +40,9 @@ int pcm_play(unsigned rate, unsigned channels,
              void *cookie)
 {
     struct msm_audio_config config;
+#if 0
     struct msm_audio_stats stats;
+#endif
     unsigned sz, n;
     char buf[8192];
     int afd;
@@ -72,7 +74,7 @@ int pcm_play(unsigned rate, unsigned channels,
     for (n = 0; n < config.buffer_count; n++) {
         if (fill(buf, sz, cookie))
             break;
-        if (write(afd, buf, sz) != sz)
+        if (write(afd, buf, sz) != (ssize_t) sz)
             break;
     }
 
@@ -86,11 +88,10 @@ int pcm_play(unsigned rate, unsigned channels,
 #endif
         if (fill(buf, sz, cookie))
             break;
-        if (write(afd, buf, sz) != sz)
+        if (write(afd, buf, sz) != (ssize_t) sz)
             break;
     }
 
-done:
     close(afd);
     return 0;
 }
@@ -142,7 +143,7 @@ void play_file(unsigned rate, unsigned channels,
         fprintf(stderr,"could not allocate %d bytes\n", count);
         return;
     }
-    if (read(fd, next, count) != count) {
+    if (read(fd, next, count) != (ssize_t) count) {
         fprintf(stderr,"could not read %d bytes\n", count);
         return;
     }
@@ -153,7 +154,6 @@ void play_file(unsigned rate, unsigned channels,
 int wav_play(const char *fn)
 {
 	struct wav_header hdr;
-    unsigned rate, channels;
 	int fd;
 	fd = open(fn, O_RDONLY);
 	if (fd < 0) {
@@ -195,7 +195,7 @@ int wav_rec(const char *fn, unsigned channels, unsigned rate)
     struct wav_header hdr;
     unsigned char buf[8192];
     struct msm_audio_config cfg;
-    unsigned sz, n;
+    unsigned sz;
     int fd, afd;
     unsigned total = 0;
     unsigned char tmp;
@@ -265,11 +265,11 @@ int wav_rec(const char *fn, unsigned channels, unsigned rate)
         while (read(0, &tmp, 1) == 1) {
             if ((tmp == 13) || (tmp == 10)) goto done;
         }
-        if (read(afd, buf, sz) != sz) {
+        if (read(afd, buf, sz) != (ssize_t) sz) {
             perror("cannot read buffer");
             goto fail;
         }
-        if (write(fd, buf, sz) != sz) {
+        if (write(fd, buf, sz) != (ssize_t) sz) {
             perror("cannot write buffer");
             goto fail;
         }
diff --git a/taskstats/Android.mk b/taskstats/Android.mk
index 1a3cbdb7..38044f08 100644
--- a/taskstats/Android.mk
+++ b/taskstats/Android.mk
@@ -12,5 +12,6 @@ LOCAL_SHARED_LIBRARIES := \
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE:= taskstats
+LOCAL_CFLAGS:= -Wall -Werror
 
 include $(BUILD_EXECUTABLE)
diff --git a/tests/audio/alsa/Android.mk b/tests/audio/alsa/Android.mk
index c6e5a8af..7d37af96 100644
--- a/tests/audio/alsa/Android.mk
+++ b/tests/audio/alsa/Android.mk
@@ -20,6 +20,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE_TAGS := tests
 LOCAL_MODULE := pcmtest
 LOCAL_SRC_FILES := pcmtest.cpp
+LOCAL_CFLAGS:= -Wall -Werror
 LOCAL_SHARED_LIBRARIES += libcutils libutils liblog libtinyalsa
 LOCAL_STATIC_LIBRARIES += libtestUtil
 LOCAL_C_INCLUDES += system/extras/tests/include external/tinyalsa/include
diff --git a/tests/binder/benchmarks/Android.mk b/tests/binder/benchmarks/Android.mk
index b43dd326..e3812ff7 100644
--- a/tests/binder/benchmarks/Android.mk
+++ b/tests/binder/benchmarks/Android.mk
@@ -36,5 +36,6 @@ LOCAL_C_INCLUDES += \
 LOCAL_MODULE := binderAddInts
 LOCAL_COMPATIBILITY_SUITE := device-tests
 LOCAL_SRC_FILES := binderAddInts.cpp
+LOCAL_CFLAGS:= -Wall -Werror
 
 include $(BUILD_NATIVE_BENCHMARK)
diff --git a/tests/cpueater/Android.mk b/tests/cpueater/Android.mk
index 0bb08d9d..3ee7a379 100644
--- a/tests/cpueater/Android.mk
+++ b/tests/cpueater/Android.mk
@@ -20,7 +20,7 @@ LOCAL_MODULE := cpueater
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := eng
 LOCAL_SRC_FILES := cpueater.c
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
@@ -28,6 +28,7 @@ LOCAL_MODULE := daemonize
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := eng
 LOCAL_SRC_FILES := daemonize.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES := libhardware_legacy
 include $(BUILD_EXECUTABLE)
 
diff --git a/tests/crypto/Android.mk b/tests/crypto/Android.mk
index e118e5d0..d48f7229 100644
--- a/tests/crypto/Android.mk
+++ b/tests/crypto/Android.mk
@@ -7,5 +7,5 @@ include $(CLEAR_VARS)
 LOCAL_SRC_FILES:= get_dm_versions.c
 LOCAL_MODULE:= get_dm_versions
 LOCAL_MODULE_TAGS := optional
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 include $(BUILD_EXECUTABLE)
diff --git a/tests/crypto/get_dm_versions.c b/tests/crypto/get_dm_versions.c
index 8ffe0a19..ba6b8953 100644
--- a/tests/crypto/get_dm_versions.c
+++ b/tests/crypto/get_dm_versions.c
@@ -27,7 +27,6 @@ int main(int argc, char *argv[])
     char buffer[DM_CRYPT_BUF_SIZE];
     struct dm_ioctl *io;
     struct dm_target_versions *v;
-    int i;
     int fd;
 
     fd = open("/dev/device-mapper", O_RDWR);
diff --git a/tests/directiotest/Android.mk b/tests/directiotest/Android.mk
index fb5f12a2..2bde675f 100644
--- a/tests/directiotest/Android.mk
+++ b/tests/directiotest/Android.mk
@@ -5,4 +5,5 @@ LOCAL_MODULE := directiotest
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := eng
 LOCAL_SRC_FILES := directiotest.c
+LOCAL_CFLAGS := -Wall -Werror
 include $(BUILD_EXECUTABLE)
diff --git a/tests/ext4/Android.mk b/tests/ext4/Android.mk
index bdd4072a..a9a684d2 100644
--- a/tests/ext4/Android.mk
+++ b/tests/ext4/Android.mk
@@ -5,6 +5,7 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= rand_emmc_perf.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE:= rand_emmc_perf
 LOCAL_MULTILIB := both
 LOCAL_MODULE_STEM_32:= rand_emmc_perf
diff --git a/tests/framebuffer/Android.mk b/tests/framebuffer/Android.mk
index 7f4c7125..1c4f5df7 100644
--- a/tests/framebuffer/Android.mk
+++ b/tests/framebuffer/Android.mk
@@ -9,7 +9,7 @@ LOCAL_SHARED_LIBRARIES := \
 
 LOCAL_MODULE:= test-fb-refresh
 
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 
 include $(BUILD_EXECUTABLE)
 
@@ -20,5 +20,5 @@ LOCAL_SRC_FILES := fb_test.c
 LOCAL_MODULE = test-fb-simple
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 LOCAL_STATIC_LIBRARIES := libc
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 include $(BUILD_EXECUTABLE)
diff --git a/tests/framebuffer/fb_test.c b/tests/framebuffer/fb_test.c
index 0b8bc68c..6d386299 100644
--- a/tests/framebuffer/fb_test.c
+++ b/tests/framebuffer/fb_test.c
@@ -206,7 +206,6 @@ uint32_t black32 = 0x0;
 
 void draw_grid(int w, int h, void* _loc) {
     int i, j;
-    int v;
     int stride = fi.line_length / (vi.bits_per_pixel >> 3);
     uint16_t *loc = _loc;
     uint32_t *loc32 = _loc;
diff --git a/tests/framebuffer/refresh.c b/tests/framebuffer/refresh.c
index 38e78719..0c2bb9d5 100644
--- a/tests/framebuffer/refresh.c
+++ b/tests/framebuffer/refresh.c
@@ -32,7 +32,6 @@ int main(int argc, char** argv)
             0 };
     int fd = -1;
     int i=0;
-    int j=0;
     char name[64];
     while ((fd==-1) && device_template[i]) {
         snprintf(name, 64, device_template[i], 0);
diff --git a/tests/fstest/Android.mk b/tests/fstest/Android.mk
index 8ea48818..52f113ce 100644
--- a/tests/fstest/Android.mk
+++ b/tests/fstest/Android.mk
@@ -18,6 +18,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE_TAGS := tests
 LOCAL_MODULE := recovery_test
 LOCAL_SRC_FILES := recovery_test.cpp
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES += libcutils libutils libbase liblog \
                           liblogwrap libext4_utils
 LOCAL_STATIC_LIBRARIES += libtestUtil libfs_mgr
diff --git a/tests/fstest/recovery_test.cpp b/tests/fstest/recovery_test.cpp
index e2371395..c34607d6 100644
--- a/tests/fstest/recovery_test.cpp
+++ b/tests/fstest/recovery_test.cpp
@@ -216,7 +216,6 @@ class FsRecoveryTest : public ::testing::Test {
       UMOUNT_BIN,
       cache_str,
     };
-    int status;
     return android_fork_execvp_ext(ARRAY_SIZE(umount_argv), umount_argv,
                                    NULL, true, LOG_KLOG, false, NULL,
                                    NULL, 0) >= 0;
@@ -230,7 +229,6 @@ class FsRecoveryTest : public ::testing::Test {
       storage_str,
       mountall_str,
     };
-    int status;
     return android_fork_execvp_ext(ARRAY_SIZE(mountall_argv), mountall_argv,
                                    NULL, true, LOG_KLOG, false, NULL,
                                    NULL, 0) >= 0;
diff --git a/tests/iptables/qtaguid/Android.mk b/tests/iptables/qtaguid/Android.mk
index 6328883d..bc09bdd8 100644
--- a/tests/iptables/qtaguid/Android.mk
+++ b/tests/iptables/qtaguid/Android.mk
@@ -23,6 +23,6 @@ LOCAL_SRC_FILES := socketTag.cpp
 LOCAL_SHARED_LIBRARIES += libcutils libutils liblog libbase
 LOCAL_STATIC_LIBRARIES += libtestUtil
 LOCAL_C_INCLUDES += system/extras/tests/include
-LOCAL_CFLAGS += -fno-strict-aliasing
+LOCAL_CFLAGS += -Wall -Werror -fno-strict-aliasing
 
 include $(BUILD_NATIVE_TEST)
diff --git a/tests/kernel.config/Android.mk b/tests/kernel.config/Android.mk
index 0c87107f..aa506c08 100644
--- a/tests/kernel.config/Android.mk
+++ b/tests/kernel.config/Android.mk
@@ -33,7 +33,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE := kernel-config-unit-tests
 LOCAL_MODULE_TAGS := tests
 LOCAL_CFLAGS := $(test_c_flags)
-LOCAL_CFLAGS := -DHAS_KCMP
+LOCAL_CFLAGS += -DHAS_KCMP
 LOCAL_SRC_FILES := $(test_src_files)
 LOCAL_SHARED_LIBRARIES := libbase
 include $(BUILD_NATIVE_TEST)
@@ -42,7 +42,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE := CtsKernelConfigTestCases
 LOCAL_MODULE_TAGS := optional
 LOCAL_CFLAGS := $(test_c_flags)
-LOCAL_CFLAGS := -DHAS_KCMP
+LOCAL_CFLAGS += -DHAS_KCMP
 LOCAL_SRC_FILES := $(cts_src_files)
 LOCAL_MODULE_PATH := $(TARGET_OUT_DATA)/nativetest
 LOCAL_MULTILIB := both
@@ -60,4 +60,5 @@ LOCAL_SRC_FILES := \
     scrape_mmap_addr.cpp
 
 LOCAL_MODULE := scrape_mmap_addr
+LOCAL_CFLAGS := -Wall -Werror
 include $(BUILD_NATIVE_TEST)
diff --git a/tests/pagingtest/Android.mk b/tests/pagingtest/Android.mk
index 727e3b81..de952ce3 100644
--- a/tests/pagingtest/Android.mk
+++ b/tests/pagingtest/Android.mk
@@ -10,6 +10,8 @@ LOCAL_SRC_FILES:=    \
 
 LOCAL_MODULE:= pagingtest
 
+LOCAL_CFLAGS := -Wall -Werror
+
 LOCAL_MODULE_TAGS := tests
 
 LOCAL_MODULE_PATH := $(local_target_dir)
diff --git a/tests/pagingtest/mmap_test.c b/tests/pagingtest/mmap_test.c
index d0d9846a..93859880 100644
--- a/tests/pagingtest/mmap_test.c
+++ b/tests/pagingtest/mmap_test.c
@@ -10,7 +10,6 @@
 int mmap_test(int test_runs, unsigned long long alloc_size) {
     void *buf;
     int ret = -1;
-    int rc;
     int i;
     struct timeval begin_time, end_time, elapsed_time;
     struct timeval total_time_mmap, total_time_munmap, total_time_in, total_time_out;
@@ -43,8 +42,8 @@ int mmap_test(int test_runs, unsigned long long alloc_size) {
 
     ret = 0;
     goto end;
-err:
-    munmap(buf, alloc_size);
+// err:
+    munmap(buf, alloc_size); // unreached?
 end:
 err_map:
     return ret;
diff --git a/tests/pftest/Android.mk b/tests/pftest/Android.mk
index bedbd0cb..1f829370 100644
--- a/tests/pftest/Android.mk
+++ b/tests/pftest/Android.mk
@@ -13,6 +13,6 @@ LOCAL_MODULE:= pftest
 LOCAL_MODULE_TAGS := optional
 
 ## LOCAL_CFLAGS += -fstack-protector-all
-LOCAL_CFLAGS += -fomit-frame-pointer
+LOCAL_CFLAGS += -fomit-frame-pointer -Wall -Werror
 
 include $(BUILD_EXECUTABLE)
diff --git a/tests/schedtest/Android.mk b/tests/schedtest/Android.mk
index 036c9fec..a018cb50 100644
--- a/tests/schedtest/Android.mk
+++ b/tests/schedtest/Android.mk
@@ -6,6 +6,6 @@ LOCAL_SRC_FILES := \
 	schedtest.c
 
 LOCAL_MODULE := schedtest
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wno-unused-parameter -Wall -Werror
 
 include $(BUILD_EXECUTABLE)
diff --git a/tests/storage/Android.mk b/tests/storage/Android.mk
index 462ebef6..41bbd661 100644
--- a/tests/storage/Android.mk
+++ b/tests/storage/Android.mk
@@ -6,12 +6,14 @@ include $(CLEAR_VARS)
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := opentest.c
 LOCAL_MODULE := opentest
+LOCAL_CFLAGS      := -Wall -Werror
 LOCAL_MODULE_TAGS := optional
 include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES   := wipe_blkdev.c
 LOCAL_MODULE      := wipe_blkdev
+LOCAL_CFLAGS      := -Wall -Werror
 LOCAL_MODULE_TAGS := optional
 include $(BUILD_EXECUTABLE)
 
diff --git a/tests/timetest/Android.mk b/tests/timetest/Android.mk
index 0485caec..af3447fd 100644
--- a/tests/timetest/Android.mk
+++ b/tests/timetest/Android.mk
@@ -5,6 +5,7 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := timetest.c
 LOCAL_MODULE := timetest
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE_TAGS := tests
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 LOCAL_STATIC_LIBRARIES := libc
diff --git a/tests/uevents/Android.mk b/tests/uevents/Android.mk
index fb8a8518..46e712d4 100644
--- a/tests/uevents/Android.mk
+++ b/tests/uevents/Android.mk
@@ -6,6 +6,6 @@ LOCAL_SRC_FILES := uevents.c
 LOCAL_SHARED_LIBRARIES += libcutils
 LOCAL_MODULE:= uevents
 
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 
 include $(BUILD_EXECUTABLE)
diff --git a/verity/Android.mk b/verity/Android.mk
index e379a475..7ddf75f6 100644
--- a/verity/Android.mk
+++ b/verity/Android.mk
@@ -5,6 +5,7 @@ ifeq ($(HOST_OS),linux)
 include $(CLEAR_VARS)
 LOCAL_MODULE := verify_boot_signature
 LOCAL_SRC_FILES := verify_boot_signature.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE_CLASS := EXECUTABLES
 LOCAL_MODULE_TAGS := optional
 LOCAL_SHARED_LIBRARIES := libcrypto
@@ -16,6 +17,7 @@ endif # HOST_OS == linux
 include $(CLEAR_VARS)
 LOCAL_MODULE := generate_verity_key
 LOCAL_SRC_FILES := generate_verity_key.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE_CLASS := EXECUTABLES
 LOCAL_MODULE_TAGS := optional
 LOCAL_SHARED_LIBRARIES := libcrypto_utils libcrypto
diff --git a/verity/verify_boot_signature.c b/verity/verify_boot_signature.c
index 36760ad7..e1c53d81 100644
--- a/verity/verify_boot_signature.c
+++ b/verity/verify_boot_signature.c
@@ -92,7 +92,6 @@ static uint64_t page_align(uint64_t n, uint64_t page_size)
  */
 static int get_signature_offset(int fd, off64_t *offset)
 {
-    int i;
     struct boot_img_hdr hdr;
 
     if (!offset) {