Fix crc calculation error, code-style issues and other fixes

TESTS/mbed_platform/crash_reporting/main.cpp

@@ -29,7 +29,8 @@
 #define MSG_KEY_DEVICE_READY "crash_reporting_ready"
 #define MSG_KEY_DEVICE_ERROR "crash_reporting_inject_error"
 
-void mbed_error_reboot_callback(mbed_error_ctx *error_context) {
+void mbed_error_reboot_callback(mbed_error_ctx *error_context)
+{
     TEST_ASSERT_EQUAL_UINT(MBED_ERROR_OUT_OF_MEMORY, error_context->error_status);
     TEST_ASSERT_EQUAL_UINT(1, error_context->error_reboot_count);
     mbed_reset_reboot_error_info();
@@ -46,12 +47,15 @@ void test_crash_reporting()
     static char _key[MSG_KEY_LEN + 1] = { };
     static char _value[MSG_VALUE_LEN + 1] = { };
 
+    printf("\nWaiting for inject error\n");
     greentea_parse_kv(_key, _value, MSG_KEY_LEN, MSG_VALUE_LEN);
+    printf("\nGot inject error\n");
     if (strcmp(_key, MSG_KEY_DEVICE_ERROR) == 0) {
+        printf("\nErroring...\n");
         MBED_ERROR1(MBED_ERROR_OUT_OF_MEMORY, "Executing crash reporting test.", 0xDEADBAD);
         TEST_ASSERT_MESSAGE(0, "crash_reporting() error call failed.");
     }
-
+    printf("\nWaiting for inject error");
     TEST_ASSERT_MESSAGE(0, "Unexpected message received.");
 }
 

platform/mbed_error.c

@@ -40,7 +40,7 @@
 #define ERROR_REPORT(ctx, error_msg, error_filename, error_line, print_thread_info) print_error_report(ctx, error_msg, error_filename, error_line, print_thread_info)
 static void print_error_report(const mbed_error_ctx *ctx, const char *, const char *error_filename, int error_line, bool print_thread_info);
 #else
-#define ERROR_REPORT(ctx, error_msg, error_filename, error_line) ((void) 0)
+#define ERROR_REPORT(ctx, error_msg, error_filename, error_line, print_thread_info) ((void) 0)
 #endif
 
 static core_util_atomic_flag error_in_progress = CORE_UTIL_ATOMIC_FLAG_INIT;
@@ -66,13 +66,14 @@ static mbed_error_status_t handle_error(mbed_error_status_t error_status, unsign
 //we dont have many uses cases to create a C wrapper for MbedCRC and the data
 //we calculate CRC on in this context is very less we will use a local
 //implementation here.
-static unsigned int compute_crc32(void *data, int datalen)
+static unsigned int compute_crc32(const void *data, int datalen)
 {
     const unsigned int polynomial = 0x04C11DB7; /* divisor is 32bit */
     unsigned int crc = 0; /* CRC value is 32bit */
+    unsigned char *buf = (unsigned char *)data;//use a temp variable to make code readable and to avoid typecasting issues.
     
-    for ( ;datalen>=0; datalen-- ) {
+    for (; datalen>0; datalen-- ) {
-        unsigned char b = (*(unsigned char *)data);
+        unsigned char b = *buf++;
         crc ^= (unsigned int)(b << 24); /* move byte into upper 8bit */
         for (int i = 0; i < 8; i++) {
             /* is MSB 1 */
@@ -191,7 +192,8 @@ static mbed_error_status_t handle_error(mbed_error_status_t error_status, unsign
     return MBED_SUCCESS;
 }
 
-WEAK void mbed_error_reboot_callback(mbed_error_ctx *error_context) {
+WEAK void mbed_error_reboot_callback(mbed_error_ctx *error_context)
+{
     //Dont do anything here, let application override this if required.
 }
 
@@ -200,9 +202,12 @@ mbed_error_status_t mbed_error_initialize(void)
 {
 #if MBED_CONF_PLATFORM_CRASH_CAPTURE_ENABLED
     uint32_t crc_val = 0;
+    
+    //Just check if we have valid value for error_status, if error_status is positive(which is not valid), no need to check crc
+    if (report_error_ctx->error_status < 0) {
         crc_val = compute_crc32(report_error_ctx, offsetof(mbed_error_ctx, crc_error_ctx));
         //Read report_error_ctx and check if CRC is correct, and with valid status code
-    if ((report_error_ctx->crc_error_ctx == crc_val) && (report_error_ctx->is_error_processed == 0) && (report_error_ctx->error_status < 0)) {
+        if ((report_error_ctx->crc_error_ctx == crc_val) && (report_error_ctx->is_error_processed == 0)) {
             is_reboot_error_valid = true;
 #if MBED_CONF_PLATFORM_REBOOT_CRASH_REPORT_ENABLED && !defined(NDEBUG)
             //Report the error info
@@ -224,8 +229,8 @@ mbed_error_status_t mbed_error_initialize(void)
             crc_val = compute_crc32(report_error_ctx, offsetof(mbed_error_ctx, crc_error_ctx));
             report_error_ctx->crc_error_ctx = crc_val;
         }
+    }
 #endif
-    
     return MBED_SUCCESS;
 }
 
@@ -291,8 +296,6 @@ WEAK MBED_NORETURN mbed_error_status_t mbed_error(mbed_error_status_t error_stat
 #endif
 #endif
     mbed_halt_system();
-    
-    return MBED_ERROR_FAILED_OPERATION;
 }
 
 //Register an application defined callback with error handling