Ambiguous references do not necessarily cause compilation errors (issue 5736).

runtime/vm/class_finalizer.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/class_finalizer.h"
 
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
 #include "vm/longjump.h"
@@ skipping 447 matching lines @@
   // Verify that the target constructor of the redirection exists.
   target = target_class.LookupConstructor(target_name);
   if (target.IsNull()) {
     target = target_class.LookupFactory(target_name);
   }
   if (target.IsNull()) {
     const String& user_visible_target_name =
         identifier.IsNull() ? target_class_name : target_name;
     // Replace the type with a malformed type and compile a throw when called.
     type = NewFinalizedMalformedType(
+        Error::Handle(),  // No previous error.
         cls,
         factory.token_pos(),
+        kTryResolve,  // No compile-time error.
         "class '%s' has no constructor or factory named '%s'",
         target_class_name.ToCString(),
         user_visible_target_name.ToCString());
     factory.SetRedirectionType(type);
     ASSERT(factory.RedirectionTarget() == Function::null());
     return;
   }
 
   // Verify that the target is compatible with the redirecting factory.
   if (!target.HasCompatibleParametersWith(factory)) {
     type = NewFinalizedMalformedType(
+        Error::Handle(),  // No previous error.
         cls,
         factory.token_pos(),
+        kTryResolve,  // No compile-time error.
         "constructor '%s' has incompatible parameters with "
         "redirecting factory '%s'",
         String::Handle(target.name()).ToCString(),
         String::Handle(factory.name()).ToCString());
     factory.SetRedirectionType(type);
     ASSERT(factory.RedirectionTarget() == Function::null());
     return;
   }
 
   // Verify that the target is const if the the redirecting factory is const.
@@ skipping 37 matching lines @@
   }
   factory.SetRedirectionType(target_type);
   factory.SetRedirectionTarget(target_target);
 }
 
 
 void ClassFinalizer::ResolveType(const Class& cls,
                                  const AbstractType& type,
                                  FinalizationKind finalization) {
   if (type.IsResolved() || type.IsFinalized()) {
+    if ((finalization == kCanonicalizeWellFormed) && type.IsMalformed()) {
+      ReportError(Error::Handle(type.malformed_error()));
+    }
     return;
   }
   if (FLAG_trace_type_finalization) {
     OS::Print("Resolve type '%s'\n", String::Handle(type.Name()).ToCString());
   }
 
   // Resolve the type class.
   if (!type.HasResolvedTypeClass()) {
     // Type parameters are always resolved in the parser in the correct
     // non-static scope or factory scope. That resolution scope is unknown here.
@@ skipping 119 matching lines @@
     }
     FinalizeTypeArguments(super_class, arguments, finalization);
   }
 }
 
 
 RawAbstractType* ClassFinalizer::FinalizeType(const Class& cls,
                                               const AbstractType& type,
                                               FinalizationKind finalization) {
   if (type.IsFinalized()) {
-    // Ensure type is canonical if canonicalization is requested.
+    // Ensure type is canonical if canonicalization is requested, unless type is
+    // malformed.
     if (finalization >= kCanonicalize) {
-      return type.Canonicalize();
+      if (type.IsMalformed()) {
+        if (finalization == kCanonicalizeWellFormed) {
+          ReportError(Error::Handle(type.malformed_error()));
+        }
+      } else {
+        return type.Canonicalize();
+      }
     }
     return type.raw();
   }
   ASSERT(type.IsResolved());
   ASSERT(finalization >= kFinalize);
 
   if (FLAG_trace_type_finalization) {
     OS::Print("Finalize type '%s'\n", String::Handle(type.Name()).ToCString());
   }
 
@@ skipping 836 matching lines @@
     type.set_is_finalized_instantiated();
     // Do not canonicalize malformed types, since they may not be resolved.
   } else {
     // The only case where the malformed type was already finalized is when its
     // type arguments are not within bounds. In that case, we have a prev_error.
     ASSERT(!prev_error.IsNull());
   }
 }
 
 
-RawType* ClassFinalizer::NewFinalizedMalformedType(const Class& cls,
-                                                   intptr_t type_pos,
-                                                   const char* format, ...) {
+RawType* ClassFinalizer::NewFinalizedMalformedType(
+    const Error& prev_error,
+    const Class& cls,
+    intptr_t type_pos,
+    FinalizationKind finalization,
+    const char* format, ...) {
   va_list args;
   va_start(args, format);
   const String& no_name = String::Handle(Symbols::Empty());
   const UnresolvedClass& unresolved_class = UnresolvedClass::Handle(
       UnresolvedClass::New(LibraryPrefix::Handle(), no_name, type_pos));
   const Type& type = Type::Handle(
       Type::New(unresolved_class, TypeArguments::Handle(), type_pos));
-  ReportMalformedType(Error::Handle(), cls, type, kTryResolve, format, args);
+  ReportMalformedType(prev_error, cls, type, finalization, format, args);
   va_end(args);
   ASSERT(type.IsMalformed());
   return type.raw();
 }
 
 
 void ClassFinalizer::FinalizeMalformedType(const Error& prev_error,
                                            const Class& cls,
                                            const Type& type,
                                            FinalizationKind finalization,
@@ skipping 26 matching lines @@
 void ClassFinalizer::ReportError(const char* format, ...) {
   va_list args;
   va_start(args, format);
   const Error& error = Error::Handle(
       Parser::FormatError(Script::Handle(), -1, "Error", format, args));
   va_end(args);
   ReportError(error);
 }
 
 }  // namespace dart