Dart_PropagateError, take 2.

runtime/vm/compiler.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_COMPILER_H_
 #define VM_COMPILER_H_
 
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
 #include "vm/runtime_entry.h"
 
 namespace dart {
 
 // Forward declarations.
 class Class;
 class Function;
 class Library;
 class RawInstance;
 class Script;
 class SequenceNode;
 
 DECLARE_RUNTIME_ENTRY(CompileFunction);
 
 class Compiler : public AllStatic {
  public:
   // Extracts class, interface, function symbols from the script and populates
   // the symbol tables and the class dictionary of the library.
-  static void Compile(const Library& library, const Script& script);
+  //
+  // Returns Error::null() if there is no compilation error.
+  static RawError* Compile(const Library& library, const Script& script);
 
   // Generates code for given function and sets its code field.
-  static void CompileFunction(const Function& function);
+  //
+  // Returns Error::null() if there is no compilation error.
+  static RawError* CompileFunction(const Function& function);
 
   // Generates optimized code for function.
-  static void CompileOptimizedFunction(const Function& function);
+  //
+  // Returns Error::null() if there is no compilation error.
+  static RawError* CompileOptimizedFunction(const Function& function);
 
   // Generates and executes code for a given code fragment, e.g. a
   // compile time constant expression. Returns the result returned
   // by the fragment.
-  static RawInstance* ExecuteOnce(SequenceNode* fragment);
+  //
+  // The return value is either a RawInstance on success or a RawError
+  // on compilation failure.
+  static RawObject* ExecuteOnce(SequenceNode* fragment);
 
   // Eagerly compiles all functions in a class.
-  static void CompileAllFunctions(const Class& cls);
+  //
+  // Returns Error::null() if there is no compilation error.
+  static RawError* CompileAllFunctions(const Class& cls);
 };
 
 }  // namespace dart
 
 #endif  // VM_COMPILER_H_