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1 // Copyright 2011 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "src/v8.h"
6 
7 #include "src/api.h"
8 #include "src/execution.h"
9 #include "src/messages.h"
10 #include "src/spaces-inl.h"
11 
12 namespace v8 {
13 namespace internal {
14 
15 
16 // If no message listeners have been registered this one is called
17 // by default.
DefaultMessageReport(Isolate * isolate,const MessageLocation * loc,Handle<Object> message_obj)18 void MessageHandler::DefaultMessageReport(Isolate* isolate,
19                                           const MessageLocation* loc,
20                                           Handle<Object> message_obj) {
21   SmartArrayPointer<char> str = GetLocalizedMessage(isolate, message_obj);
22   if (loc == NULL) {
23     PrintF("%s\n", str.get());
24   } else {
25     HandleScope scope(isolate);
26     Handle<Object> data(loc->script()->name(), isolate);
27     SmartArrayPointer<char> data_str;
28     if (data->IsString())
29       data_str = Handle<String>::cast(data)->ToCString(DISALLOW_NULLS);
30     PrintF("%s:%i: %s\n", data_str.get() ? data_str.get() : "<unknown>",
31            loc->start_pos(), str.get());
32   }
33 }
34 
35 
MakeMessageObject(Isolate * isolate,const char * type,MessageLocation * loc,Vector<Handle<Object>> args,Handle<JSArray> stack_frames)36 Handle<JSMessageObject> MessageHandler::MakeMessageObject(
37     Isolate* isolate,
38     const char* type,
39     MessageLocation* loc,
40     Vector< Handle<Object> > args,
41     Handle<JSArray> stack_frames) {
42   Factory* factory = isolate->factory();
43   Handle<String> type_handle = factory->InternalizeUtf8String(type);
44   Handle<FixedArray> arguments_elements =
45       factory->NewFixedArray(args.length());
46   for (int i = 0; i < args.length(); i++) {
47     arguments_elements->set(i, *args[i]);
48   }
49   Handle<JSArray> arguments_handle =
50       factory->NewJSArrayWithElements(arguments_elements);
51 
52   int start = 0;
53   int end = 0;
54   Handle<Object> script_handle = factory->undefined_value();
55   if (loc) {
56     start = loc->start_pos();
57     end = loc->end_pos();
58     script_handle = Script::GetWrapper(loc->script());
59   }
60 
61   Handle<Object> stack_frames_handle = stack_frames.is_null()
62       ? Handle<Object>::cast(factory->undefined_value())
63       : Handle<Object>::cast(stack_frames);
64 
65   Handle<JSMessageObject> message =
66       factory->NewJSMessageObject(type_handle,
67                                   arguments_handle,
68                                   start,
69                                   end,
70                                   script_handle,
71                                   stack_frames_handle);
72 
73   return message;
74 }
75 
76 
ReportMessage(Isolate * isolate,MessageLocation * loc,Handle<Object> message)77 void MessageHandler::ReportMessage(Isolate* isolate,
78                                    MessageLocation* loc,
79                                    Handle<Object> message) {
80   // We are calling into embedder's code which can throw exceptions.
81   // Thus we need to save current exception state, reset it to the clean one
82   // and ignore scheduled exceptions callbacks can throw.
83 
84   // We pass the exception object into the message handler callback though.
85   Object* exception_object = isolate->heap()->undefined_value();
86   if (isolate->has_pending_exception()) {
87     exception_object = isolate->pending_exception();
88   }
89   Handle<Object> exception_handle(exception_object, isolate);
90 
91   Isolate::ExceptionScope exception_scope(isolate);
92   isolate->clear_pending_exception();
93   isolate->set_external_caught_exception(false);
94 
95   v8::Local<v8::Message> api_message_obj = v8::Utils::MessageToLocal(message);
96   v8::Local<v8::Value> api_exception_obj = v8::Utils::ToLocal(exception_handle);
97 
98   v8::NeanderArray global_listeners(isolate->factory()->message_listeners());
99   int global_length = global_listeners.length();
100   if (global_length == 0) {
101     DefaultMessageReport(isolate, loc, message);
102     if (isolate->has_scheduled_exception()) {
103       isolate->clear_scheduled_exception();
104     }
105   } else {
106     for (int i = 0; i < global_length; i++) {
107       HandleScope scope(isolate);
108       if (global_listeners.get(i)->IsUndefined()) continue;
109       v8::NeanderObject listener(JSObject::cast(global_listeners.get(i)));
110       Handle<Foreign> callback_obj(Foreign::cast(listener.get(0)));
111       v8::MessageCallback callback =
112           FUNCTION_CAST<v8::MessageCallback>(callback_obj->foreign_address());
113       Handle<Object> callback_data(listener.get(1), isolate);
114       {
115         // Do not allow exceptions to propagate.
116         v8::TryCatch try_catch;
117         callback(api_message_obj, callback_data->IsUndefined()
118                                       ? api_exception_obj
119                                       : v8::Utils::ToLocal(callback_data));
120       }
121       if (isolate->has_scheduled_exception()) {
122         isolate->clear_scheduled_exception();
123       }
124     }
125   }
126 }
127 
128 
GetMessage(Isolate * isolate,Handle<Object> data)129 Handle<String> MessageHandler::GetMessage(Isolate* isolate,
130                                           Handle<Object> data) {
131   Factory* factory = isolate->factory();
132   Handle<String> fmt_str =
133       factory->InternalizeOneByteString(STATIC_ASCII_VECTOR("FormatMessage"));
134   Handle<JSFunction> fun = Handle<JSFunction>::cast(Object::GetProperty(
135           isolate->js_builtins_object(), fmt_str).ToHandleChecked());
136   Handle<JSMessageObject> message = Handle<JSMessageObject>::cast(data);
137   Handle<Object> argv[] = { Handle<Object>(message->type(), isolate),
138                             Handle<Object>(message->arguments(), isolate) };
139 
140   MaybeHandle<Object> maybe_result = Execution::TryCall(
141       fun, isolate->js_builtins_object(), ARRAY_SIZE(argv), argv);
142   Handle<Object> result;
143   if (!maybe_result.ToHandle(&result) || !result->IsString()) {
144     return factory->InternalizeOneByteString(STATIC_ASCII_VECTOR("<error>"));
145   }
146   Handle<String> result_string = Handle<String>::cast(result);
147   // A string that has been obtained from JS code in this way is
148   // likely to be a complicated ConsString of some sort.  We flatten it
149   // here to improve the efficiency of converting it to a C string and
150   // other operations that are likely to take place (see GetLocalizedMessage
151   // for example).
152   result_string = String::Flatten(result_string);
153   return result_string;
154 }
155 
156 
GetLocalizedMessage(Isolate * isolate,Handle<Object> data)157 SmartArrayPointer<char> MessageHandler::GetLocalizedMessage(
158     Isolate* isolate,
159     Handle<Object> data) {
160   HandleScope scope(isolate);
161   return GetMessage(isolate, data)->ToCString(DISALLOW_NULLS);
162 }
163 
164 
165 } }  // namespace v8::internal
166