Minor error-sending cleanup. Produce callstacks.

git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@4126 ed5197a5-7fde-0310-b194-c3ffbd925b24

src/ssb.c

@@ -25,6 +25,15 @@
 #include <time.h>
 #include <uv.h>
 
+#include <backtrace.h>
+
+#ifndef _WIN32
+#ifndef __ANDROID__
+#include <execinfo.h>
+#endif
+#include <unistd.h>
+#endif
+
 #if !defined(_countof)
 #define _countof(a) ((int)(sizeof((a)) / sizeof(*(a))))
 #endif
@@ -622,30 +631,68 @@ void tf_ssb_connection_rpc_send_json(tf_ssb_connection_t* connection, uint8_t fl
 	JS_FreeValue(context, json);
 }
 
+static int _tf_ssb_backtrace_callback(void* data, uintptr_t pc, const char* filename, int line_number, const char* function)
+{
+	char** stack = data;
+	char line[256];
+	int length = snprintf(line, sizeof(line), "%p %s:%d %s\n", (void*)pc, filename, line_number, function);
+	int current = *stack ? strlen(*stack) : 0;
+	*stack = tf_resize_vec(*stack, current + length + 1);
+	memcpy(*stack + current, line, length + 1);
+	return 0;
+}
+
+static void _tf_ssb_backtrace_error(void* data, const char* message, int error)
+{
+	char** stack = data;
+	int length = strlen(message);
+	if (message)
+	{
+		int current = *stack ? strlen(*stack) : 0;
+		*stack = tf_resize_vec(*stack, current + length + 1);
+		memcpy(*stack + current, message, length + 1);
+	}
+}
+
+static char* _tf_ssb_backtrace_string()
+{
+	extern struct backtrace_state* g_backtrace_state;
+	int count = 0;
+	void* buffer[32];
+	char* string = NULL;
+#ifdef _WIN32
+	count = CaptureStackBackTrace(0, sizeof(buffer) / sizeof(*buffer), buffer, NULL);
+#elif !defined(__ANDROID__)
+	count = backtrace(buffer, sizeof(buffer) / sizeof(*buffer));
+#endif
+	for (int i = 0; i < count; i++)
+	{
+		backtrace_pcinfo(
+			g_backtrace_state, 
+			(uintptr_t)buffer[i],
+			_tf_ssb_backtrace_callback,
+			_tf_ssb_backtrace_error,
+			&string);
+	}
+	return string;
+}
+
 void tf_ssb_connection_rpc_send_error(tf_ssb_connection_t* connection, uint8_t flags, int32_t request_number, const char* error)
 {
 	JSContext* context = connection->ssb->context;
 	JSValue message = JS_NewObject(context);
+	char* stack = _tf_ssb_backtrace_string();
 	JS_SetPropertyStr(context, message, "name", JS_NewString(context, "Error"));
-	JS_SetPropertyStr(context, message, "stack", JS_NewString(context, "none"));
+	JS_SetPropertyStr(context, message, "stack", JS_NewString(context, stack));
 	JS_SetPropertyStr(context, message, "message", JS_NewString(context, error));
-	tf_ssb_connection_rpc_send_json(connection, flags | k_ssb_rpc_flag_end_error, request_number, message, NULL, NULL, NULL);
+	tf_ssb_connection_rpc_send_json(connection, ((flags & k_ssb_rpc_flag_stream) ? (k_ssb_rpc_flag_stream | k_ssb_rpc_flag_end_error) : 0), request_number, message, NULL, NULL, NULL);
 	JS_FreeValue(context, message);
+	tf_free(stack);
 }
 
 void tf_ssb_connection_rpc_send_error_method_not_allowed(tf_ssb_connection_t* connection, uint8_t flags, int32_t request_number)
 {
-	const char* k_unsupported = "{\"message\": \"method: is not in list of allowed methods\", \"name\": \"Error\", \"stack\": \"none\"}";
+	tf_ssb_connection_rpc_send_error(connection, flags, request_number, "method is not in list of allowed methods");
-	tf_ssb_connection_rpc_send(
-		connection,
-		k_ssb_rpc_flag_json |
-			((flags & k_ssb_rpc_flag_stream) ? (k_ssb_rpc_flag_stream | k_ssb_rpc_flag_end_error) : 0),
-		request_number,
-		(const uint8_t*)k_unsupported,
-		strlen(k_unsupported),
-		NULL,
-		NULL,
-		NULL);
 }
 
 static int _utf8_len(uint8_t ch)
@@ -1378,8 +1425,7 @@ static void _tf_ssb_connection_rpc_recv(tf_ssb_connection_t* connection, uint8_t
 		}
 	}
 
-	if (request_number < 0 &&
+	if (flags & k_ssb_rpc_flag_end_error)
-		(flags & k_ssb_rpc_flag_end_error))
 	{
 		_tf_ssb_connection_remove_request(connection, -request_number);
 	}