Fix error string to include information about class and library when the snapshot writer throws an …

runtime/vm/snapshot.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/exceptions.h"
@@ skipping 1037 matching lines @@
                                uint8_t** buffer,
                                ReAlloc alloc,
                                intptr_t initial_size)
     : BaseWriter(buffer, alloc, initial_size),
       kind_(kind),
       isolate_(Isolate::Current()),
       object_store_(isolate_->object_store()),
       class_table_(isolate_->class_table()),
       forward_list_(kMaxPredefinedObjectIds),
       exception_type_(Exceptions::kNone),
-      exception_msg_(NULL) {
+      exception_msg_(NULL),
+      unmarked_objects_(false) {
 }
 
 
 void SnapshotWriter::WriteObject(RawObject* rawobj) {
   WriteObjectImpl(rawobj);
   WriteForwardedObjects();
 }
 
 
 void SnapshotWriter::HandleVMIsolateObject(RawObject* rawobj) {
@@ skipping 534 matching lines @@
     } else {
       WriteObjectRef(data[i]);
     }
   }
 }
 
 
 void SnapshotWriter::CheckIfSerializable(RawClass* cls) {
   if (Class::IsSignatureClass(cls)) {
     // We do not allow closure objects in an isolate message.
-    SetWriteException(Exceptions::kArgument,
-                      "Illegal argument in isolate message"
-                      " : (object is a closure)");
+    Isolate* isolate = Isolate::Current();
+    HANDLESCOPE(isolate);
+    const char* format = "Illegal argument in isolate message"
+                         " : (object is a closure - %s %s)";
+    UnmarkAll();  // Unmark objects now as we are about to print stuff.
+    const Class& clazz = Class::Handle(isolate, cls);
+    const Function& func = Function::Handle(isolate,
+                                            clazz.signature_function());
+    ASSERT(!func.IsNull());
+    intptr_t len = OS::SNPrint(NULL, 0, format,
+                               clazz.ToCString(), func.ToCString()) + 1;
+    char* chars = isolate->current_zone()->Alloc<char>(len);
+    OS::SNPrint(chars, len, format, clazz.ToCString(), func.ToCString());
+    SetWriteException(Exceptions::kArgument, chars);
   }
   if (cls->ptr()->num_native_fields_ != 0) {
     // We do not allow objects with native fields in an isolate message.
-    SetWriteException(Exceptions::kArgument,
-                      "Illegal argument in isolate message"
-                      " : (object extends NativeWrapper)");
+    Isolate* isolate = Isolate::Current();
+    HANDLESCOPE(Isolate::Current());
+    const char* format = "Illegal argument in isolate message"
+                         " : (object extends NativeWrapper - %s)";
+    UnmarkAll();  // Unmark objects now as we are about to print stuff.
+    const Class& clazz = Class::Handle(isolate, cls);
+    intptr_t len = OS::SNPrint(NULL, 0, format, clazz.ToCString()) + 1;
+    char* chars = isolate->current_zone()->Alloc<char>(len);
+    OS::SNPrint(chars, len, format, clazz.ToCString());
+    SetWriteException(Exceptions::kArgument, chars);
   }
 }
 
 
 void SnapshotWriter::SetWriteException(Exceptions::ExceptionType type,
                                        const char* msg) {
   set_exception_type(type);
   set_exception_msg(msg);
   // The more specific error is set up in SnapshotWriter::ThrowException().
   isolate()->long_jump_base()->
@@ skipping 143 matching lines @@
     NoGCScope no_gc;
     WriteObject(obj.raw());
     UnmarkAll();
   } else {
     ThrowException(exception_type(), exception_msg());
   }
 }
 
 
 }  // namespace dart