Rewrite all units and other logic to better use return values and added TRY() helper

utils/error.c

@@ -21,6 +21,13 @@
 
 #include "platform.h"
 
+static const char *const error_names[] = {
+#define X(name, text) STR(name),
+    X_ERROR_CODES
+#undef X
+};
+COMPILER_ASSERT(ERROR_COUNT == ELEMENTS_IN_ARRAY(error_names));
+
 static const char *const error_message[] = {
 #define X(name, text) text,
     X_ERROR_CODES
@@ -28,18 +35,33 @@ static const char *const error_message[] = {
 };
 COMPILER_ASSERT(ERROR_COUNT == ELEMENTS_IN_ARRAY(error_message));
 
-const char *error_get_string(error_t error)
+const char *error_get_message(error_t error)
 {
-    const char *msg = 0;
+    const char *msg = NULL;
 
     if (error < ERROR_COUNT) {
         msg = error_message[error];
     }
 
-    if (0 == msg) {
-        assert_param(0);
-        msg = "";
+    if (NULL == msg) {
+        return error_get_name(error);
     }
 
     return msg;
 }
+
+const char *error_get_name(error_t error)
+{
+    const char *name = 0;
+
+    if (error < ERROR_COUNT) {
+        name = error_names[error];
+    }
+
+    if (0 == name) {
+        dbg("%d", (int)error);
+        trap("MISSING ERROR NAME");
+    }
+
+    return name;
+}

utils/error.h

@@ -26,25 +26,35 @@
 }
 #endif
 
+// fields: name, msg. If msg is NULL, name as string will be used instead.
 #define X_ERROR_CODES \
     /* Shared errors */  \
-    X(SUCCESS,"OK") \
-    X(FAILURE,"Failure") \
-    X(INTERNAL,"Internal error") \
-    X(LOADING,"Init in progress") \
+    X(SUCCESS, NULL) /* operation succeeded / unit loaded */ \
+    X(FAILURE, NULL) /* generic error */   \
+    X(INTERNAL_ERROR, NULL) /* a bug */    \
+    X(LOADING, NULL) /* unit is loading */ \
+    X(UNKNOWN_COMMAND, NULL) \
+    X(BAD_COUNT, NULL) \
+    X(MALFORMED_COMMAND, NULL) \
+    X(NOT_APPLICABLE, NULL) \
+    X(HW_TIMEOUT, NULL) \
+    X(NO_SUCH_UNIT, NULL) \
+    X(OVERRUN, NULL) /* used in bulk transfer */ \
+    X(PROTOCOL_BREACH, NULL) /* eating with the wrong spoon */  \
     \
-    /* VFS user errors */ \
-    X(ERROR_DURING_TRANSFER,"Error during transfer") \
-    X(TRANSFER_TIMEOUT,"Transfer timed out") \
-    /*X(FILE_BOUNDS,"Possible mismatch between file size and size programmed")*/ \
-    X(OOO_SECTOR,"File sent out of order by PC") \
+    /* VFS user errors (those are meant to be shown to user) */ \
+    X(ERROR_DURING_TRANSFER, "Error during transfer") \
+    X(TRANSFER_TIMEOUT, "Transfer timed out") \
+    X(OOO_SECTOR, "File sent out of order by PC") \
     \
-    /* File stream errors */ \
-    X(SUCCESS_DONE,"End of stream") \
-    X(SUCCESS_DONE_OR_CONTINUE,"End of stream, or more to come") \
+    /* File stream errors/status */ \
+    X(SUCCESS_DONE, NULL) \
+    X(SUCCESS_DONE_OR_CONTINUE, NULL) \
     \
     /* Unit loading */ \
     X(BAD_CONFIG, "Configuration error") \
+    X(BAD_KEY, "Unexpected config key") \
+    X(BAD_VALUE, "Bad config value") \
     X(OUT_OF_MEM, "Not enough RAM") \
     X(RESOURCE_NOT_AVAILABLE, "Required pin / peripheral not available")
 
@@ -56,7 +66,15 @@ typedef enum {
     ERROR_COUNT
 } error_t;
 
-const char *error_get_string(error_t error) __attribute__((pure));
+const char *error_get_message(error_t error) __attribute__((pure));
+const char *error_get_name(error_t error) __attribute__((pure));
+
+/** Check return value and return it if not E_SUCCESS */
+#define TRY(call) do { \
+    error_t _rv; \
+    _rv = call; \
+    if (E_SUCCESS != _rv) return _rv; \
+} while (0)
 
 #ifdef __cplusplus
 }