Fix warnings and set Werror flag to not let them happen again.

Test: it builds.
Bug: b/37159108
Change-Id: I898f5de0f8e992404977d4958b8dd44af4aea9fe

5 files changed, 4 insertions, 6 deletions

diff --git a/jni_jpegstream/Android.mk b/jni_jpegstream/Android.mk
index b13d4fb35..cac2a7b72 100644
--- a/jni_jpegstream/Android.mk
+++ b/jni_jpegstream/Android.mk
@@ -17,6 +17,7 @@ LOCAL_SDK_VERSION   := 17
 LOCAL_ARM_MODE := arm
 
 LOCAL_CFLAGS    += -ffast-math -O3 -funroll-loops
+LOCAL_CFLAGS += -Wall -Wextra -Werror
 LOCAL_LDLIBS := -llog
 
 LOCAL_CPP_EXTENSION := .cpp
diff --git a/jni_jpegstream/src/jerr_hook.cpp b/jni_jpegstream/src/jerr_hook.cpp
index f8f864f78..c8491ccbd 100644
--- a/jni_jpegstream/src/jerr_hook.cpp
+++ b/jni_jpegstream/src/jerr_hook.cpp
@@ -34,7 +34,6 @@ void ErrExit(j_common_ptr cinfo) {
  * to logcat's error log.
  */
 void ErrOutput(j_common_ptr cinfo) {
-    ErrManager* mgr = reinterpret_cast<ErrManager*>(cinfo->err);
     char buf[JMSG_LENGTH_MAX];
     (*cinfo->err->format_message) (cinfo, buf);
     buf[JMSG_LENGTH_MAX - 1] = '\0';  // Force null terminator
diff --git a/jni_jpegstream/src/jpeg_hook.cpp b/jni_jpegstream/src/jpeg_hook.cpp
index cca54e405..db04c18e1 100644
--- a/jni_jpegstream/src/jpeg_hook.cpp
+++ b/jni_jpegstream/src/jpeg_hook.cpp
@@ -121,7 +121,7 @@ void Mgr_skip_input_data_fcn(j_decompress_ptr cinfo, long num_bytes) {
         return;
     }
     SourceManager *src = reinterpret_cast<SourceManager*>(cinfo->src);
-    if (src->mgr.bytes_in_buffer >= num_bytes) {
+    if (src->mgr.bytes_in_buffer >= (size_t)num_bytes) {
         src->mgr.bytes_in_buffer -= num_bytes;
         src->mgr.next_input_byte += num_bytes;
     } else {
@@ -149,7 +149,7 @@ void Mgr_skip_input_data_fcn(j_decompress_ptr cinfo, long num_bytes) {
     }
 }
 
-void Mgr_term_source_fcn(j_decompress_ptr cinfo) {
+void Mgr_term_source_fcn(j_decompress_ptr cinfo __unused) {
     //noop
 }
 
diff --git a/jni_jpegstream/src/jpeg_reader.cpp b/jni_jpegstream/src/jpeg_reader.cpp
index 4726b6426..9662152da 100644
--- a/jni_jpegstream/src/jpeg_reader.cpp
+++ b/jni_jpegstream/src/jpeg_reader.cpp
@@ -215,7 +215,6 @@ void JpegReader::formatPixels(uint8_t* buf, int32_t len) {
     // Do endianness and alpha for output format
     if (mFormat == Jpeg_Config::FORMAT_RGBA) {
         // Set alphas to 255
-        uint8_t* end = buf + len - 1;
         for (int i = len - 1; i >= 0; i -= 4) {
             buf[i] = 255;
             buf[i - 1] = *--iter;
@@ -224,7 +223,6 @@ void JpegReader::formatPixels(uint8_t* buf, int32_t len) {
         }
     } else if (mFormat == Jpeg_Config::FORMAT_ABGR) {
         // Reverse endianness and set alphas to 255
-        uint8_t* end = buf + len - 1;
         int r, g, b;
         for (int i = len - 1; i >= 0; i -= 4) {
             b = *--iter;
diff --git a/jni_jpegstream/src/jpegstream.cpp b/jni_jpegstream/src/jpegstream.cpp
index 3b9a6830b..afff64ce1 100644
--- a/jni_jpegstream/src/jpegstream.cpp
+++ b/jni_jpegstream/src/jpegstream.cpp
@@ -323,7 +323,7 @@ static int registerNativeMethods(JNIEnv* env, const char* className,
     return JNI_TRUE;
 }
 
-jint JNI_OnLoad(JavaVM* vm, void* reserved) {
+jint JNI_OnLoad(JavaVM* vm, void* reserved __unused) {
     JNIEnv* env;
     if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
         LOGE("Error: GetEnv failed in JNI_OnLoad");