fix buffer overflow in error handling module

- fixed ring buffer overflow in errcatch module
- fixed naming of commands in sercomm module
- added comments to macro's in consts.h
- properly handle `W2_E_WARN_UNCAUGHT_ERROR` and
  `W2_E_WARN_ERR_BUFFER_FULL` (these used to cause infinite loops)
- added buffer full warning code
- added options to hide some simulation messages
- more boilerplate sercomm module code

1 files changed, 19 insertions, 6 deletions

diff --git a/robot/errcatch.c b/robot/errcatch.c
index 1262a38..f66b2a1 100644
--- a/robot/errcatch.c
+++ b/robot/errcatch.c
@@ -8,15 +8,25 @@
 #include "modes.h"
 #include "orangutan_shim.h"
 
-w2_s_error *g_w2_error_buffer[W2_E_BUFFER_SIZE] = {};
-uint8_t g_w2_error_index						= 0;
-uint8_t g_w2_error_offset						= 0;
+w2_s_error *g_w2_error_buffer[W2_ERROR_BUFFER_SIZE] = {};
+uint8_t g_w2_error_index							= 0;
+uint8_t g_w2_error_offset							= 0;
+uint8_t g_w2_error_buffer_full						= 0;
+uint8_t g_w2_error_uncaught							= 0;
 
 void w2_errcatch_main() {
 	while (g_w2_error_index != g_w2_error_offset) {
 		w2_s_error *error = g_w2_error_buffer[g_w2_error_offset];
 		w2_errcatch_handle_error(error);
-		g_w2_error_offset = (g_w2_error_offset + 1) % W2_E_BUFFER_SIZE;
+		g_w2_error_offset = (g_w2_error_offset + 1) % W2_ERROR_BUFFER_SIZE;
+	}
+	if (g_w2_error_buffer_full) {
+		w2_errcatch_throw(W2_E_WARN_ERR_BUFFER_FULL);
+		g_w2_error_buffer_full = 0;
+	}
+	if (g_w2_error_uncaught) {
+		w2_errcatch_throw(W2_E_WARN_UNCAUGHT_ERROR);
+		g_w2_error_uncaught = 0;
 	}
 }
 
@@ -30,10 +40,13 @@ w2_s_error *w2_alloc_error(enum w2_e_errorcodes code, uint16_t length, const cha
 
 void w2_errcatch_throw(enum w2_e_errorcodes code) { w2_errcatch_throw_msg(code, 0, ""); }
 void w2_errcatch_throw_msg(enum w2_e_errorcodes code, uint16_t length, const char *message) {
+	uint8_t next_index	   = (g_w2_error_index + 1) % W2_ERROR_BUFFER_SIZE;
+	g_w2_error_buffer_full = next_index == g_w2_error_offset;
 	free(g_w2_error_buffer[g_w2_error_index]);
 	w2_s_error *error					= w2_alloc_error(code, length, message);
 	g_w2_error_buffer[g_w2_error_index] = error;
-	g_w2_error_index					= (g_w2_error_index + 1) % W2_E_BUFFER_SIZE;
+	if (g_w2_error_buffer_full) return;
+	g_w2_error_index = next_index;
 }
 
 void w2_errcatch_handle_error(w2_s_error *error) {
@@ -48,7 +61,7 @@ void w2_errcatch_handle_error(w2_s_error *error) {
 			break;
 		}
 		default: {
-			w2_errcatch_throw(W2_E_WARN_UNCAUGHT_ERROR);
+			g_w2_error_uncaught = 1;
 #ifdef W2_SIM
 			simwarn("Uncaught/unhandled error found with code 0x%02x\n", error->code);
 #endif