Introduce the Error object class in the vm. It represents all of the

runtime/vm/raw_object.h

 // Copyright (c) 2011, 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.
 
 #ifndef VM_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "vm/assert.h"
 #include "vm/globals.h"
 #include "vm/snapshot.h"
@@ skipping 19 matching lines @@
   V(Script)                                                                    \
   V(Library)                                                                   \
   V(LibraryPrefix)                                                             \
   V(Code)                                                                      \
   V(Instructions)                                                              \
   V(PcDescriptors)                                                             \
   V(LocalVarDescriptors)                                                       \
   V(ExceptionHandlers)                                                         \
   V(Context)                                                                   \
   V(ContextScope)                                                              \
-  V(UnhandledException)                                                        \
-  V(ApiError)                                                                  \
+  V(Error)                                                                     \
+    V(ApiError)                                                                \
+    V(LanguageError)                                                           \
+    V(UnhandledException)                                                      \
+    V(UnwindError)                                                             \
   V(Instance)                                                                  \
     V(Number)                                                                  \
       V(Integer)                                                               \
         V(Smi)                                                                 \
         V(Mint)                                                                \
         V(Bigint)                                                              \
       V(Double)                                                                \
     V(String)                                                                  \
       V(OneByteString)                                                         \
       V(TwoByteString)                                                         \
@@ skipping 667 matching lines @@
   // Variable length data follows here.
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->data_[0]); }
   RawObject* data_[0];
   RawObject** to(intptr_t num_vars) {
     intptr_t data_length = num_vars * (sizeof(VariableDesc)/kWordSize);
     return reinterpret_cast<RawObject**>(&ptr()->data_[data_length - 1]);
   }
 };
 
 
-class RawUnhandledException : public RawObject {
+class RawError : public RawObject {
+  RAW_HEAP_OBJECT_IMPLEMENTATION(Error);
+};
+
+
+class RawApiError : public RawError {
+  RAW_HEAP_OBJECT_IMPLEMENTATION(ApiError);
+
+  RawObject** from() {
+    return reinterpret_cast<RawObject**>(&ptr()->message_);
+  }
+  RawString* message_;
+  RawObject** to() {
+    return reinterpret_cast<RawObject**>(&ptr()->message_);
+  }
+};
+
+
+class RawLanguageError : public RawError {
+  RAW_HEAP_OBJECT_IMPLEMENTATION(LanguageError);
+
+  RawObject** from() {
+    return reinterpret_cast<RawObject**>(&ptr()->message_);
+  }
+  RawString* message_;
+  RawObject** to() {
+    return reinterpret_cast<RawObject**>(&ptr()->message_);
+  }
+};
+
+
+class RawUnhandledException : public RawError {
   RAW_HEAP_OBJECT_IMPLEMENTATION(UnhandledException);
 
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->exception_);
   }
   RawInstance* exception_;
   RawInstance* stacktrace_;
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->stacktrace_);
   }
 };
 
 
-class RawApiError : public RawObject {
-  RAW_HEAP_OBJECT_IMPLEMENTATION(ApiError);
+class RawUnwindError : public RawError {
+  RAW_HEAP_OBJECT_IMPLEMENTATION(UnwindError);
 
   RawObject** from() {
-    return reinterpret_cast<RawObject**>(&ptr()->data_);
+    return reinterpret_cast<RawObject**>(&ptr()->message_);
   }
-  RawObject* data_;
+  RawString* message_;
   RawObject** to() {
-    return reinterpret_cast<RawObject**>(&ptr()->data_);
+    return reinterpret_cast<RawObject**>(&ptr()->message_);
   }
 };
 
 
 class RawInstance : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Instance);
 };
 
 
 class RawNumber : public RawInstance {
@@ skipping 200 matching lines @@
   intptr_t type_;  // Uninitialized, simple or complex.
   intptr_t flags_;  // Represents global/local, case insensitive, multiline.
 
   // Variable length data follows here.
   uint8_t data_[0];
 };
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_