From 231223086cef64b71a33ffe5e167b1addfc0fed7 Mon Sep 17 00:00:00 2001
From: M4x1m3 <M4x1me@protonmail.com>
Date: Wed, 15 Jul 2020 11:38:40 +0200
Subject: [PATCH] [mpy] Added passing errors to JS

---
 python/port/port.cpp | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/python/port/port.cpp b/python/port/port.cpp
index bc2ee4113..83fe8c910 100644
--- a/python/port/port.cpp
+++ b/python/port/port.cpp
@@ -7,6 +7,38 @@
 #include <string.h>
 #include <setjmp.h>
 
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+
+void python_error_start(const char* type) {
+  EM_ASM({
+    Module.___temp_python_error = new Object();
+    Module.___temp_python_error["stacktrace"] = new Array();
+    Module.___temp_python_error["type"] = Module.UTF8ToString($0);
+  }, type);
+}
+
+void python_error_add_trace(const char* file, int line, const char* block) {
+  EM_ASM({
+    var temp_obj = new Object();
+    temp_obj["file"] = Module.UTF8ToString($0);
+    temp_obj["line"] = $1;
+    temp_obj["block"] = Module.UTF8ToString($2);
+    Module.___temp_python_error.stacktrace.push(temp_obj);
+  }, file, line, block);
+}
+
+void python_error_end() {
+  EM_ASM({
+    if (typeof Module.onPythonError === "function") {
+      Module.onPythonError(Module.___temp_python_error); 
+    }
+    delete Module.___temp_python_error;
+  });
+}
+#endif
+
+
 /* py/parsenum.h is a C header which uses C keyword restrict.
  * It does not exist in C++ so we define it here in order to be able to include
  * py/parsenum.h header. */
@@ -65,6 +97,10 @@ bool MicroPython::ExecutionEnvironment::runCode(const char * str) {
      * because we want to print custom information, we copied and modified the
      * content of mp_obj_print_exception instead of calling it. */
     if (mp_obj_is_exception_instance((mp_obj_t)nlr.ret_val)) {
+#ifdef __EMSCRIPTEN__
+      mp_obj_exception_t* the_exception = (mp_obj_exception_t*) MP_OBJ_TO_PTR((mp_obj_t)nlr.ret_val);
+      python_error_start(qstr_str(the_exception->base.type->name));
+#endif
         size_t n, *values;
         mp_obj_exception_get_traceback((mp_obj_t)nlr.ret_val, &n, &values);
         if (n > 0) {
@@ -74,6 +110,9 @@ bool MicroPython::ExecutionEnvironment::runCode(const char * str) {
                 if (values[i] == 0) {
                   mp_printf(&mp_plat_print, "  Last command\n");
                 } else {
+#ifdef __EMSCRIPTEN__
+                  python_error_add_trace((const char*) qstr_str(values[i]), (int) values[i + 1], (const char*) qstr_str(values[i+2]));
+#endif
 #if MICROPY_ENABLE_SOURCE_LINE
                   mp_printf(&mp_plat_print, "  File \"%q\", line %d", values[i], (int)values[i + 1]);
 #else
@@ -90,6 +129,9 @@ bool MicroPython::ExecutionEnvironment::runCode(const char * str) {
               }
             }
         }
+#ifdef __EMSCRIPTEN__
+      python_error_end();
+#endif
     }
     mp_obj_print_helper(&mp_plat_print, (mp_obj_t)nlr.ret_val, PRINT_EXC);
     mp_print_str(&mp_plat_print, "\n");