Add an imported into list for libraries so that it is possible to lookup

vm/object.cc

Index: vm/object.cc
===================================================================
--- vm/object.cc	(revision 557)
+++ vm/object.cc	(working copy)
@@ -3406,22 +3406,46 @@
 }
 
 
-ClassDictionaryIterator::ClassDictionaryIterator(const Library& library)
+DictionaryIterator::DictionaryIterator(const Library& library)
     : array_(Array::Handle(library.dictionary())),
       // Last element in array is a Smi.
       size_(Array::Handle(library.dictionary()).Length() - 1),
       next_ix_(0) {
+  MoveToNextObject();
+}
+
+
+RawObject* DictionaryIterator::GetNext() {
+  ASSERT(HasNext());
+  int ix = next_ix_++;
+  MoveToNextObject();
+  ASSERT(array_.At(ix) != Object::null());
+  return array_.At(ix);
+}
+
+
+void DictionaryIterator::MoveToNextObject() {
+  Object& obj = Object::Handle(array_.At(next_ix_));
+  while (obj.IsNull() && HasNext()) {
+    next_ix_++;
+    obj = array_.At(next_ix_);
+  }
+}
+
+
+ClassDictionaryIterator::ClassDictionaryIterator(const Library& library)
+    : DictionaryIterator(library) {
   MoveToNextClass();
 }
 
 
-RawClass* ClassDictionaryIterator::GetNext() {
+RawClass* ClassDictionaryIterator::GetNextClass() {
   ASSERT(HasNext());
   int ix = next_ix_++;
+  Object& obj = Object::Handle(array_.At(ix));
   MoveToNextClass();
-  ASSERT(array_.At(ix) != Object::null());
   Class& cls = Class::Handle();
-  cls ^= array_.At(ix);
+  cls ^= obj.raw();
   return cls.raw();
 }
 
@@ -3578,10 +3602,12 @@
 
 
 RawObject* Library::LookupObject(const String& name) const {
+  // First check if the name is found in the local scope.
   Object& obj = Object::Handle(LookupLocalObject(name));
   if (!obj.IsNull()) {
     return obj.raw();
   }
+  // Now check if the name is found in the local scope of any imported libs.
   Library& import = Library::Handle();
   Array& imports = Array::Handle(this->imports());
   for (intptr_t i = 0; i < num_imports(); i++) {
@@ -3595,6 +3621,106 @@
 }
 
 
+RawObject* Library::LookupObjectInImporter(const String& name) const {
+  const Array& imported_into_libs = Array::Handle(this->imported_into());
+  Library& importer_lib = Library::Handle();
+  Object& obj = Object::Handle();
+  for (intptr_t i = 0; i < this->num_imported_into(); i++) {
+    importer_lib ^= imported_into_libs.At(i);
+    // Check if name is found in the top level scope of the importer.
+    ASSERT(importer_lib.raw() != raw());
+    // First check if name is found in the local scope of the library into

[Ivan Posva, 2011/10/20 08:46:04]

Please factor this out as it is essentially LookupObjectFiltered(name, *this)
where the second parameter is used to filter which imported library is skipped.
LookupObject then calls LookupObjectFiltered(name, Library::Handle()).

[siva, 2011/10/20 23:08:47]

Done.

+    // which this is imported into.
+    obj = importer_lib.LookupLocalObject(name);
+    if (!obj.IsNull()) {
+      return obj.raw();
+    }
+    // Now check if name is found in the top level scope of libs imported
+    // by the importer.
+    const Array& imports = Array::Handle(importer_lib.imports());
+    Library& import_lib = Library::Handle();
+    for (intptr_t j = 0; j < importer_lib.num_imports(); j++) {
+      import_lib ^= imports.At(j);
+      if (import_lib.raw() == raw()) {
+        continue;
+      }
+      obj = import_lib.LookupLocalObject(name);
+      if (!obj.IsNull()) {
+        return obj.raw();
+      }
+    }
+  }
+  return Object::null();
+}
+
+
+RawString* Library::DuplicateDefineErrorString(const Object& obj) const {
+  Class& cls = Class::Handle();
+  Function& func = Function::Handle();
+  Field& field = Field::Handle();
+  String& errstr = String::Handle();
+  if (obj.IsClass()) {
+    cls ^= obj.raw();
+    errstr = cls.Name();
+  } else if (obj.IsFunction()) {
+    func ^= obj.raw();
+    cls ^= func.owner();
+    errstr = func.name();
+  } else if (obj.IsField()) {
+    field ^= obj.raw();
+    cls ^= field.owner();
+    errstr = field.name();
+  } else {
+    UNREACHABLE();
+  }
+  const Library& lib = Library::Handle(cls.library());
+  Array& array = Array::Handle(Array::New(5));
+  array.SetAt(0, errstr);
+  errstr = String::New(" is defined in libraries ");
+  array.SetAt(1, errstr);
+  errstr = url();
+  array.SetAt(2, errstr);
+  errstr = String::New(" and ");
+  array.SetAt(3, errstr);
+  errstr = lib.url();
+  array.SetAt(4, errstr);
+  errstr = String::ConcatAll(array);
+  return errstr.raw();
+}
+
+
+RawObject* Library::FindDuplicateDefinition() const {
+  DictionaryIterator it(*this);
+  Object& obj = Object::Handle();
+  Class& cls = Class::Handle();
+  Function& func = Function::Handle();
+  Field& field = Field::Handle();
+  String& entry_name = String::Handle();
+  while (it.HasNext()) {
+    obj = it.GetNext();
+    if (obj.IsNull()) {

[Ivan Posva, 2011/10/20 08:46:04]

I don't think the iterator is ever handing out null objects.

[siva, 2011/10/20 23:08:47]

True, I changed this to an assertion.

On 2011/10/20 08:46:04, Ivan Posva wrote:

+      continue;
+    } else if (obj.IsClass()) {
+      cls ^= obj.raw();
+      entry_name = cls.Name();
+    } else if (obj.IsFunction()) {
+      func ^= obj.raw();
+      entry_name = func.name();
+    } else if (obj.IsField()) {
+      field ^= obj.raw();
+      entry_name = field.name();
+    } else {

[Ivan Posva, 2011/10/20 08:46:04]

Please add a comment explaining why you can skip library prefixes.

[siva, 2011/10/20 23:08:47]

Added comment stating that library prefixes in this library are not visible in
the importing scope.

On 2011/10/20 08:46:04, Ivan Posva wrote:

+      continue;
+    }
+    obj = LookupObjectInImporter(entry_name);
+    if (!obj.IsNull()) {
+      return obj.raw();
+    }
+  }
+  return Object::null();
+}
+
+
 RawClass* Library::LookupClass(const String& name) const {
   Object& obj = Object::Handle(LookupObject(name));
   if (!obj.IsNull() && obj.IsClass()) {
@@ -3654,9 +3780,24 @@
   intptr_t index = num_imports();
   imports.SetAt(index, library);
   set_num_imports(index + 1);
+  library.AddImportedInto(*this);
 }
 
 
+void Library::AddImportedInto(const Library& library) const {
+  Array& imported_into = Array::Handle(this->imported_into());
+  intptr_t capacity = imported_into.Length();
+  if (num_imported_into() == capacity) {
+    capacity = capacity + kImportedIntoCapacityIncrement;
+    imported_into = Array::Grow(imported_into, capacity);
+    StorePointer(&raw_ptr()->imported_into_, imported_into.raw());
+  }
+  intptr_t index = num_imported_into();
+  imported_into.SetAt(index, library);
+  set_num_imported_into(index + 1);
+}
+
+
 void Library::InitClassDictionary() const {
   // The last element of the dictionary specifies the number of in use slots.
   // TODO(iposva): Find reasonable initial size.
@@ -3677,6 +3818,14 @@
 }
 
 
+void Library::InitImportedIntoList() const {
+  const Array& imported_into =
+      Array::Handle(Array::New(kInitialImportedIntoCapacity, Heap::kOld));
+  StorePointer(&raw_ptr()->imported_into_, imported_into.raw());
+  raw_ptr()->num_imported_into_ = 0;
+}
+
+
 RawLibrary* Library::New() {
   const Class& library_class = Class::Handle(Object::library_class());
   RawObject* raw = Object::Allocate(library_class,
@@ -3702,6 +3851,7 @@
   result.raw_ptr()->loaded_ = false;
   result.InitClassDictionary();
   result.InitImportList();
+  result.InitImportedIntoList();
   if (import_core_lib) {
     Library& core_lib = Library::Handle(Library::CoreLibrary());
     ASSERT(!core_lib.IsNull());
@@ -3753,6 +3903,25 @@
 }
 
 
+RawString* Library::CheckForDuplicateDefinition() {
+  Library& lib = Library::Handle();
+  Isolate* isolate = Isolate::Current();
+  ASSERT(isolate != NULL);
+  ObjectStore* object_store = isolate->object_store();
+  ASSERT(object_store != NULL);
+  lib ^= object_store->registered_libraries();
+  Object& obj = Object::Handle();
+  while (!lib.IsNull()) {
+    obj = lib.FindDuplicateDefinition();
+    if (!obj.IsNull()) {
+      return lib.DuplicateDefineErrorString(obj);
+    }
+    lib ^= lib.next_registered();
+  }
+  return String::null();
+}
+
+
 bool Library::IsKeyUsed(intptr_t key) {
   intptr_t lib_key;
   Library& lib = Library::Handle();
@@ -3846,7 +4015,7 @@
   while (!lib.IsNull()) {
     ClassDictionaryIterator it(lib);
     while (it.HasNext()) {
-      cls ^= it.GetNext();
+      cls ^= it.GetNextClass();
       if (!cls.is_interface()) {
         Compiler::CompileAllFunctions(cls);
       }