Print exception hint in the debugger client when an exception is thrown. (#1841)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg [email protected]

Author: zherczeg

jerry-core/debugger/jerry-debugger.c

@@ -16,12 +16,14 @@
 #ifdef JERRY_DEBUGGER
 
 #include "byte-code.h"
+#include "ecma-builtin-helpers.h"
 #include "ecma-conversion.h"
 #include "ecma-eval.h"
 #include "ecma-objects.h"
 #include "jcontext.h"
 #include "jerry-debugger.h"
 #include "jerryscript-port.h"
+#include "lit-char-helpers.h"
 
 /**
  * Type cast the debugger send buffer into a specific type.
@@ -715,4 +717,151 @@ jerry_debugger_send_memstats (void)
   jerry_debugger_send (sizeof (jerry_debugger_send_memstats_t));
 } /* jerry_debugger_send_memstats */
 
+/*
+ * Converts an standard error into a string.
+ *
+ * @return standard error string
+ */
+static ecma_string_t *
+jerry_debugger_exception_object_to_string (ecma_value_t exception_obj_value) /**< exception object */
+{
+  ecma_object_t *object_p = ecma_get_object_from_value (exception_obj_value);
+
+  ecma_object_t *prototype_p = ecma_get_object_prototype (object_p);
+
+  if (prototype_p == NULL
+      || ecma_get_object_type (prototype_p) != ECMA_OBJECT_TYPE_GENERAL
+      || !ecma_get_object_is_builtin (prototype_p))
+  {
+    return NULL;
+  }
+
+  lit_magic_string_id_t string_id;
+
+  switch (((ecma_extended_object_t *) prototype_p)->u.built_in.id)
+  {
+#ifndef CONFIG_DISABLE_ERROR_BUILTINS
+    case ECMA_BUILTIN_ID_EVAL_ERROR_PROTOTYPE:
+    {
+      string_id = LIT_MAGIC_STRING_EVAL_ERROR_UL;
+      break;
+    }
+    case ECMA_BUILTIN_ID_RANGE_ERROR_PROTOTYPE:
+    {
+      string_id = LIT_MAGIC_STRING_RANGE_ERROR_UL;
+      break;
+    }
+    case ECMA_BUILTIN_ID_REFERENCE_ERROR_PROTOTYPE:
+    {
+      string_id = LIT_MAGIC_STRING_REFERENCE_ERROR_UL;
+      break;
+    }
+    case ECMA_BUILTIN_ID_SYNTAX_ERROR_PROTOTYPE:
+    {
+      string_id = LIT_MAGIC_STRING_SYNTAX_ERROR_UL;
+      break;
+    }
+    case ECMA_BUILTIN_ID_TYPE_ERROR_PROTOTYPE:
+    {
+      string_id = LIT_MAGIC_STRING_TYPE_ERROR_UL;
+      break;
+    }
+    case ECMA_BUILTIN_ID_URI_ERROR_PROTOTYPE:
+    {
+      string_id = LIT_MAGIC_STRING_URI_ERROR_UL;
+      break;
+    }
+#endif /* !CONFIG_DISABLE_ERROR_BUILTINS */
+    case ECMA_BUILTIN_ID_ERROR_PROTOTYPE:
+    {
+      string_id = LIT_MAGIC_STRING_ERROR_UL;
+      break;
+    }
+    default:
+    {
+      return NULL;
+    }
+  }
+
+  lit_utf8_size_t size = lit_get_magic_string_size (string_id);
+  JERRY_ASSERT (size <= 14);
+
+  lit_utf8_byte_t data[16];
+  memcpy (data, lit_get_magic_string_utf8 (string_id), size);
+
+  ecma_string_t message_string;
+  ecma_init_ecma_magic_string (&message_string, LIT_MAGIC_STRING_MESSAGE);
+
+  ecma_property_t *property_p;
+  property_p = ecma_find_named_property (ecma_get_object_from_value (exception_obj_value),
+                                         &message_string);
+
+  if (property_p == NULL
+      || ECMA_PROPERTY_GET_TYPE (*property_p) != ECMA_PROPERTY_TYPE_NAMEDDATA)
+  {
+    return ecma_new_ecma_string_from_utf8 (data, size);
+  }
+
+  ecma_property_value_t *prop_value_p = ECMA_PROPERTY_VALUE_PTR (property_p);
+
+  if (!ecma_is_value_string (prop_value_p->value))
+  {
+    return ecma_new_ecma_string_from_utf8 (data, size);
+  }
+
+  data[size] = LIT_CHAR_COLON;
+  data[size + 1] = LIT_CHAR_SP;
+
+  ecma_string_t *type_string_p = ecma_new_ecma_string_from_utf8 (data, size + 2);
+
+  ecma_string_t *string_p = ecma_concat_ecma_strings (type_string_p,
+                                                      ecma_get_string_from_value (prop_value_p->value));
+  ecma_deref_ecma_string (type_string_p);
+  return string_p;
+} /* jerry_debugger_exception_object_to_string */
+
+/**
+ * Send string representation of exception to the client.
+ *
+ * @return true - if the data sent successfully to the debugger client,
+ *         false - otherwise
+ */
+bool
+jerry_debugger_send_exception_string (ecma_value_t exception_value) /**< error value */
+{
+  ecma_string_t *string_p = NULL;
+
+  if (ecma_is_value_object (exception_value))
+  {
+    ecma_value_t object_value = ecma_get_value_from_error_value (exception_value);
+
+    string_p = jerry_debugger_exception_object_to_string (object_value);
+    if (string_p == NULL)
+    {
+      string_p = ecma_get_string_from_value (ecma_builtin_helper_object_to_string (object_value));
+    }
+  }
+  else if (ecma_is_value_string (exception_value))
+  {
+    string_p = ecma_get_string_from_value (exception_value);
+    ecma_ref_ecma_string (string_p);
+  }
+  else
+  {
+    exception_value = ecma_op_to_string (exception_value);
+    string_p = ecma_get_string_from_value (exception_value);
+  }
+
+  ECMA_STRING_TO_UTF8_STRING (string_p, string_data_p, string_size);
+
+  bool result = jerry_debugger_send_string (JERRY_DEBUGGER_EXCEPTION_STR,
+                                            string_data_p,
+                                            string_size);
+
+  ECMA_FINALIZE_UTF8_STRING (string_data_p, string_size);
+
+  ecma_deref_ecma_string (string_p);
+  return result;
+} /* jerry_debugger_send_exception_string */
+
 #endif /* JERRY_DEBUGGER */

jerry-core/debugger/jerry-debugger.h

@@ -102,12 +102,14 @@ typedef enum
   JERRY_DEBUGGER_MEMSTATS_RECEIVE = 14, /**< memstats sent to the client*/
   JERRY_DEBUGGER_BREAKPOINT_HIT = 15, /**< notify breakpoint hit */
   JERRY_DEBUGGER_EXCEPTION_HIT = 16, /**< notify exception hit */
-  JERRY_DEBUGGER_BACKTRACE = 17, /**< backtrace data */
-  JERRY_DEBUGGER_BACKTRACE_END = 18, /**< last backtrace data */
-  JERRY_DEBUGGER_EVAL_RESULT = 19, /**< eval result */
-  JERRY_DEBUGGER_EVAL_RESULT_END = 20, /**< last part of eval result */
-  JERRY_DEBUGGER_EVAL_ERROR = 21, /**< eval result when an error is occured */
-  JERRY_DEBUGGER_EVAL_ERROR_END = 22, /**< last part of eval result when an error is occured */
+  JERRY_DEBUGGER_EXCEPTION_STR = 17, /**< exception string fragment */
+  JERRY_DEBUGGER_EXCEPTION_STR_END = 18, /**< exception string last fragment */
+  JERRY_DEBUGGER_BACKTRACE = 19, /**< backtrace data */
+  JERRY_DEBUGGER_BACKTRACE_END = 20, /**< last backtrace data */
+  JERRY_DEBUGGER_EVAL_RESULT = 21, /**< eval result */
+  JERRY_DEBUGGER_EVAL_RESULT_END = 22, /**< last part of eval result */
+  JERRY_DEBUGGER_EVAL_ERROR = 23, /**< eval result when an error is occured */
+  JERRY_DEBUGGER_EVAL_ERROR_END = 24, /**< last part of eval result when an error is occured */
 
   /* Messages sent by the client to server. */
 
@@ -316,6 +318,7 @@ bool jerry_debugger_send_string (uint8_t message_type, const uint8_t *string_p,
 bool jerry_debugger_send_function_cp (jerry_debugger_header_type_t type, ecma_compiled_code_t *compiled_code_p);
 bool jerry_debugger_send_parse_function (uint32_t line, uint32_t column);
 void jerry_debugger_send_memstats (void);
+bool jerry_debugger_send_exception_string (ecma_value_t exception_value);
 
 #endif /* JERRY_DEBUGGER */
 

jerry-core/vm/vm.c

@@ -2550,7 +2550,10 @@ vm_loop (vm_frame_ctx_t *frame_ctx_p) /**< frame context */
           && !(frame_ctx_p->bytecode_header_p->status_flags & CBC_CODE_FLAGS_DEBUGGER_IGNORE)
           && !(JERRY_CONTEXT (debugger_flags) & (JERRY_DEBUGGER_VM_IGNORE_EXCEPTION | JERRY_DEBUGGER_VM_IGNORE)))
       {
-        jerry_debugger_breakpoint_hit (JERRY_DEBUGGER_EXCEPTION_HIT);
+        if (jerry_debugger_send_exception_string (result))
+        {
+          jerry_debugger_breakpoint_hit (JERRY_DEBUGGER_EXCEPTION_HIT);
+        }
       }
 #endif /* JERRY_DEBUGGER */
     }

jerry-debugger/jerry-client-ws.html

@@ -51,12 +51,14 @@ <h2>JerryScript HTML (WebSocket) Debugger Client</h2>
 var JERRY_DEBUGGER_MEMSTATS_RECEIVE = 14;
 var JERRY_DEBUGGER_BREAKPOINT_HIT = 15;
 var JERRY_DEBUGGER_EXCEPTION_HIT = 16;
-var JERRY_DEBUGGER_BACKTRACE = 17;
-var JERRY_DEBUGGER_BACKTRACE_END = 18;
-var JERRY_DEBUGGER_EVAL_RESULT = 19;
-var JERRY_DEBUGGER_EVAL_RESULT_END = 20;
-var JERRY_DEBUGGER_EVAL_ERROR = 21;
-var JERRY_DEBUGGER_EVAL_ERROR_END = 22;
+var JERRY_DEBUGGER_EXCEPTION_STR = 17;
+var JERRY_DEBUGGER_EXCEPTION_STR_END = 18;
+var JERRY_DEBUGGER_BACKTRACE = 19;
+var JERRY_DEBUGGER_BACKTRACE_END = 20;
+var JERRY_DEBUGGER_EVAL_RESULT = 21;
+var JERRY_DEBUGGER_EVAL_RESULT_END = 22;
+var JERRY_DEBUGGER_EVAL_ERROR = 23;
+var JERRY_DEBUGGER_EVAL_ERROR_END = 24;
 
 var JERRY_DEBUGGER_FREE_BYTE_CODE_CP = 1;
 var JERRY_DEBUGGER_UPDATE_BREAKPOINT = 2;
@@ -113,6 +115,7 @@ <h2>JerryScript HTML (WebSocket) Debugger Client</h2>
   var pendingBreakpoints = [ ];
   var backtraceFrame = 0;
   var evalResult = null;
+  var exceptionData = null;
 
   function assert(expr)
   {
@@ -830,6 +833,11 @@ <h2>JerryScript HTML (WebSocket) Debugger Client</h2>
         if (message[0] == JERRY_DEBUGGER_EXCEPTION_HIT)
         {
           appendLog("Exception throw detected (to disable automatic stop type exception 0)");
+          if (exceptionData)
+          {
+            appendLog("Exception hint: " + cesu8ToString(exceptionData));
+            exceptionData = null;
+          }
         }
 
         lastBreakpointHit = breakpoint;
@@ -847,6 +855,13 @@ <h2>JerryScript HTML (WebSocket) Debugger Client</h2>
         return;
       }
 
+      case JERRY_DEBUGGER_EXCEPTION_STR:
+      case JERRY_DEBUGGER_EXCEPTION_STR_END:
+      {
+        exceptionData = concatUint8Arrays(exceptionData, message);
+        return;
+      }
+
       case JERRY_DEBUGGER_BACKTRACE:
       case JERRY_DEBUGGER_BACKTRACE_END:
       {

jerry-debugger/jerry-client-ws.py

@@ -42,12 +42,14 @@
 JERRY_DEBUGGER_MEMSTATS_RECEIVE = 14
 JERRY_DEBUGGER_BREAKPOINT_HIT = 15
 JERRY_DEBUGGER_EXCEPTION_HIT = 16
-JERRY_DEBUGGER_BACKTRACE = 17
-JERRY_DEBUGGER_BACKTRACE_END = 18
-JERRY_DEBUGGER_EVAL_RESULT = 19
-JERRY_DEBUGGER_EVAL_RESULT_END = 20
-JERRY_DEBUGGER_EVAL_ERROR = 21
-JERRY_DEBUGGER_EVAL_ERROR_END = 22
+JERRY_DEBUGGER_EXCEPTION_STR = 17
+JERRY_DEBUGGER_EXCEPTION_STR_END = 18
+JERRY_DEBUGGER_BACKTRACE = 19
+JERRY_DEBUGGER_BACKTRACE_END = 20
+JERRY_DEBUGGER_EVAL_RESULT = 21
+JERRY_DEBUGGER_EVAL_RESULT_END = 22
+JERRY_DEBUGGER_EVAL_ERROR = 23
+JERRY_DEBUGGER_EVAL_ERROR_END = 24
 
 
 # Messages sent by the client to server.
@@ -813,6 +815,7 @@ def main():
     args = arguments_parse()
 
     debugger = JerryDebugger(args.address)
+    exception_string = ""
 
     non_interactive = args.non_interactive
 
@@ -865,6 +868,9 @@ def main():
 
             if buffer_type == JERRY_DEBUGGER_EXCEPTION_HIT:
                 print("Exception throw detected (to disable automatic stop type exception 0)")
+                if exception_string:
+                    print("Exception hint: %s" % (exception_string))
+                    exception_string = ""
 
             if breakpoint[1]:
                 breakpoint_info = "at"
@@ -880,6 +886,12 @@ def main():
             if prompt.quit:
                 break
 
+        elif buffer_type == JERRY_DEBUGGER_EXCEPTION_STR:
+            exception_string += data[3:]
+
+        elif buffer_type == JERRY_DEBUGGER_EXCEPTION_STR_END:
+            exception_string += data[3:]
+
         elif buffer_type in [JERRY_DEBUGGER_BACKTRACE, JERRY_DEBUGGER_BACKTRACE_END]:
             frame_index = 0
 

tests/debugger/do_exception.cmd

@@ -1,2 +1,5 @@
 c
+c
+c
+c
 quit

tests/debugger/do_exception.expected

@@ -2,5 +2,18 @@ Connecting to: localhost:5001
 Stopped at tests/debugger/do_exception.js:15
 (jerry-debugger) c
 Exception throw detected (to disable automatic stop type exception 0)
-Stopped at tests/debugger/do_exception.js:19 (in foo() at line:17, col:1)
+Exception hint: TypeError
+Stopped around tests/debugger/do_exception.js:19 (in foo() at line:17, col:1)
+(jerry-debugger) c
+Exception throw detected (to disable automatic stop type exception 0)
+Exception hint: ReferenceError
+Stopped at tests/debugger/do_exception.js:24 (in foo() at line:17, col:1)
+(jerry-debugger) c
+Exception throw detected (to disable automatic stop type exception 0)
+Exception hint: 456
+Stopped at tests/debugger/do_exception.js:29 (in foo() at line:17, col:1)
+(jerry-debugger) c
+Exception throw detected (to disable automatic stop type exception 0)
+Exception hint: RangeError: Bad range!
+Stopped around tests/debugger/do_exception.js:34 (in foo() at line:17, col:1)
 (jerry-debugger) quit

tests/debugger/do_exception.js

@@ -15,11 +15,25 @@
 print("exception handler configuration test")
 
 function foo() {
-    try {
-        b = a / c;
-    } catch (e) {
-        print(e); // pass exception object to err handler
-    }
+  try {
+    undefined();
+  } catch (e) {
+  }
+
+  try {
+    xxx();
+  } catch (e) {
+  }
+
+  try {
+    throw 456;
+  } catch (e) {
+  }
+
+  try {
+    throw new RangeError("Bad range!");
+  } catch (e) {
+  }
 }
 
 foo()