lambda: Add support for invoke-interface for boxed innate lambdas

Lambda closures created with the 'create-lambda' instruction
(termed "innate lambdas") can be turned into an object with 'box-lambda'.

This CL enables support for those kinds of lambdas to work with
'invoke-interface' by generating a proxy class for the lambda.

Note: MIPS32/64 support not included.

Bug: 24618608
Bug: 25107649
Change-Id: Ic8f1bb66ebeaed4097e758a50becf1cff6ccaefb
diff --git a/runtime/lambda_proxy_test.cc b/runtime/lambda_proxy_test.cc
new file mode 100644
index 0000000..63d6ccc
--- /dev/null
+++ b/runtime/lambda_proxy_test.cc
@@ -0,0 +1,367 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <jni.h>
+#include <vector>
+
+#include "art_field-inl.h"
+#include "class_linker-inl.h"
+#include "compiler_callbacks.h"
+#include "common_compiler_test.h"
+#include "mirror/field-inl.h"
+#include "mirror/lambda_proxy.h"
+#include "mirror/method.h"
+#include "scoped_thread_state_change.h"
+
+namespace art {
+
+// The enclosing class of all the interfaces used by this test.
+// -- Defined as a macro to allow for string concatenation.
+#define TEST_INTERFACE_ENCLOSING_CLASS_NAME "LambdaInterfaces"
+// Generate out "LLambdaInterfaces$<<iface>>;" , replacing <<iface>> with the interface name.
+#define MAKE_TEST_INTERFACE_NAME(iface) ("L" TEST_INTERFACE_ENCLOSING_CLASS_NAME "$" iface ";")
+
+#define ASSERT_NOT_NULL(x) ASSERT_TRUE((x) != nullptr)
+#define ASSERT_NULL(x) ASSERT_TRUE((x) == nullptr)
+#define EXPECT_NULL(x) EXPECT_TRUE((x) == nullptr)
+
+class LambdaProxyTest  // : public CommonCompilerTest {
+    : public CommonRuntimeTest {
+ public:
+  // Generate a lambda proxy class with the given name and interfaces. This is a simplification from what
+  // libcore does to fit to our test needs. We do not check for duplicated interfaces or methods and
+  // we do not declare exceptions.
+  mirror::Class* GenerateProxyClass(ScopedObjectAccess& soa,
+                                    jobject jclass_loader,
+                                    const char* class_name,
+                                    const std::vector<mirror::Class*>& interfaces)
+      SHARED_REQUIRES(Locks::mutator_lock_) {
+    CHECK(class_name != nullptr);
+    CHECK(jclass_loader != nullptr);
+
+    mirror::Class* java_lang_object =
+        class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;");
+    CHECK(java_lang_object != nullptr);
+
+    jclass java_lang_class = soa.AddLocalReference<jclass>(mirror::Class::GetJavaLangClass());
+
+    // Builds the interfaces array.
+    jobjectArray proxy_class_interfaces = soa.Env()->NewObjectArray(interfaces.size(),
+                                                                    java_lang_class,
+                                                                    nullptr);  // No initial element.
+    soa.Self()->AssertNoPendingException();
+    for (size_t i = 0; i < interfaces.size(); ++i) {
+      soa.Env()->SetObjectArrayElement(proxy_class_interfaces,
+                                       i,
+                                       soa.AddLocalReference<jclass>(interfaces[i]));
+    }
+
+    // Builds the method array.
+    jsize methods_count = 3;  // Object.equals, Object.hashCode and Object.toString.
+    for (mirror::Class* interface : interfaces) {
+      methods_count += interface->NumVirtualMethods();
+    }
+    jobjectArray proxy_class_methods =
+        soa.Env()->NewObjectArray(methods_count,
+                                  soa.AddLocalReference<jclass>(mirror::Method::StaticClass()),
+                                  nullptr);  // No initial element.
+    soa.Self()->AssertNoPendingException();
+
+    jsize array_index = 0;
+
+    //
+    // Fill the method array with the Object and all the interface's virtual methods.
+    //
+
+    // Add a method to 'proxy_class_methods'
+    auto add_method_to_array = [&](ArtMethod* method) SHARED_REQUIRES(Locks::mutator_lock_) {
+      CHECK(method != nullptr);
+      soa.Env()->SetObjectArrayElement(proxy_class_methods,
+                                       array_index++,
+                                       soa.AddLocalReference<jobject>(
+                                           mirror::Method::CreateFromArtMethod(soa.Self(),
+                                                                               method))
+                                      );  // NOLINT: [whitespace/parens] [2]
+
+      LOG(DEBUG) << "Add " << PrettyMethod(method) << " to list of methods to generate proxy";
+    };
+    // Add a method to 'proxy_class_methods' by looking it up from java.lang.Object
+    auto add_method_to_array_by_lookup = [&](const char* name, const char* method_descriptor)
+        SHARED_REQUIRES(Locks::mutator_lock_) {
+      ArtMethod* method = java_lang_object->FindDeclaredVirtualMethod(name,
+                                                                      method_descriptor,
+                                                                      sizeof(void*));
+      add_method_to_array(method);
+    };
+
+    // Add all methods from Object.
+    add_method_to_array_by_lookup("equals",   "(Ljava/lang/Object;)Z");
+    add_method_to_array_by_lookup("hashCode", "()I");
+    add_method_to_array_by_lookup("toString", "()Ljava/lang/String;");
+
+    // Now adds all interfaces virtual methods.
+    for (mirror::Class* interface : interfaces) {
+      mirror::Class* next_class = interface;
+      do {
+        for (ArtMethod& method : next_class->GetVirtualMethods(sizeof(void*))) {
+          add_method_to_array(&method);
+        }
+        next_class = next_class->GetSuperClass();
+      } while (!next_class->IsObjectClass());
+      // Skip adding any methods from "Object".
+    }
+    CHECK_EQ(array_index, methods_count);
+
+    // Builds an empty exception array.
+    jobjectArray proxy_class_throws = soa.Env()->NewObjectArray(0 /* length */,
+                                                                java_lang_class,
+                                                                nullptr /* initial element*/);
+    soa.Self()->AssertNoPendingException();
+
+    bool already_exists;
+    mirror::Class* proxy_class =
+        class_linker_->CreateLambdaProxyClass(soa,
+                                              soa.Env()->NewStringUTF(class_name),
+                                              proxy_class_interfaces,
+                                              jclass_loader,
+                                              proxy_class_methods,
+                                              proxy_class_throws,
+                                              /*out*/&already_exists);
+
+    CHECK(!already_exists);
+
+    soa.Self()->AssertNoPendingException();
+    return proxy_class;
+  }
+
+  LambdaProxyTest() {
+  }
+
+  virtual void SetUp() {
+    CommonRuntimeTest::SetUp();
+  }
+
+  virtual void SetUpRuntimeOptions(RuntimeOptions* options ATTRIBUTE_UNUSED) {
+    // Do not have any compiler options because we don't want to run as an AOT
+    // (In particular the lambda proxy class generation isn't currently supported for AOT).
+    this->callbacks_.reset();
+  }
+
+  template <typename THandleScope>
+  Handle<mirror::Class> GenerateProxyClass(THandleScope& hs,
+                                           const char* name,
+                                           const std::vector<mirror::Class*>& interfaces)
+      SHARED_REQUIRES(Locks::mutator_lock_) {
+    return hs.NewHandle(GenerateProxyClass(*soa_, jclass_loader_, name, interfaces));
+  }
+
+ protected:
+  ScopedObjectAccess* soa_ = nullptr;
+  jobject jclass_loader_ = nullptr;
+};
+
+// Creates a lambda proxy class and check ClassHelper works correctly.
+TEST_F(LambdaProxyTest, ProxyClassHelper) {
+  // gLogVerbosity.class_linker = true;  // Uncomment to enable class linker logging.
+
+  ASSERT_NOT_NULL(Thread::Current());
+
+  ScopedObjectAccess soa(Thread::Current());
+  soa_ = &soa;
+
+  // Must happen after CommonRuntimeTest finishes constructing the runtime.
+  jclass_loader_ = LoadDex(TEST_INTERFACE_ENCLOSING_CLASS_NAME);
+  jobject jclass_loader = jclass_loader_;
+
+  StackHandleScope<4> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
+
+  Handle<mirror::Class> J(hs.NewHandle(
+      class_linker_->FindClass(soa.Self(), MAKE_TEST_INTERFACE_NAME("J"), class_loader)));
+  ASSERT_TRUE(J.Get() != nullptr);
+
+  std::vector<mirror::Class*> interfaces;
+  interfaces.push_back(J.Get());
+  Handle<mirror::Class> proxy_class(hs.NewHandle(
+      GenerateProxyClass(soa, jclass_loader, "$Proxy1234", interfaces)));
+  interfaces.clear();  // Don't least possibly stale objects in the array as good practice.
+  ASSERT_TRUE(proxy_class.Get() != nullptr);
+  ASSERT_TRUE(proxy_class->IsLambdaProxyClass());
+  ASSERT_TRUE(proxy_class->IsInitialized());
+
+  EXPECT_EQ(1U, proxy_class->NumDirectInterfaces());  // LambdaInterfaces$J.
+  EXPECT_EQ(J.Get(), mirror::Class::GetDirectInterface(soa.Self(), proxy_class, 0));
+  std::string temp;
+  const char* proxy_class_descriptor = proxy_class->GetDescriptor(&temp);
+  EXPECT_STREQ("L$Proxy1234;", proxy_class_descriptor);
+  EXPECT_EQ(nullptr, proxy_class->GetSourceFile());
+
+  // Make sure all the virtual methods are marked as a proxy
+  for (ArtMethod& method : proxy_class->GetVirtualMethods(sizeof(void*))) {
+    SCOPED_TRACE(PrettyMethod(&method, /* with_signature */true));
+    EXPECT_TRUE(method.IsProxyMethod());
+    EXPECT_TRUE(method.IsLambdaProxyMethod());
+    EXPECT_FALSE(method.IsReflectProxyMethod());
+  }
+}
+
+// Creates a proxy class and check FieldHelper works correctly.
+TEST_F(LambdaProxyTest, ProxyFieldHelper) {
+  // gLogVerbosity.class_linker = true;  // Uncomment to enable class linker logging.
+
+  ASSERT_NOT_NULL(Thread::Current());
+
+  ScopedObjectAccess soa(Thread::Current());
+  soa_ = &soa;
+
+  // Must happen after CommonRuntimeTest finishes constructing the runtime.
+  jclass_loader_ = LoadDex(TEST_INTERFACE_ENCLOSING_CLASS_NAME);
+  jobject jclass_loader = jclass_loader_;
+
+  StackHandleScope<9> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
+
+  Handle<mirror::Class> I(hs.NewHandle(
+      class_linker_->FindClass(soa.Self(), MAKE_TEST_INTERFACE_NAME("I"), class_loader)));
+  ASSERT_NOT_NULL(I.Get());
+
+  // Create the lambda proxy which implements interfaces "I".
+  Handle<mirror::Class> proxy_class = GenerateProxyClass(hs,
+                                                         "$Proxy1234",
+                                                         { I.Get() });  // Interfaces.
+
+  ASSERT_NOT_NULL(proxy_class.Get());
+  EXPECT_TRUE(proxy_class->IsLambdaProxyClass());
+  EXPECT_TRUE(proxy_class->IsInitialized());
+  EXPECT_NULL(proxy_class->GetIFieldsPtr());
+
+  LengthPrefixedArray<ArtField>* static_fields = proxy_class->GetSFieldsPtr();
+  ASSERT_NOT_NULL(static_fields);
+
+  // Must have "throws" and "interfaces" static fields.
+  ASSERT_EQ(+mirror::LambdaProxy::kStaticFieldCount, proxy_class->NumStaticFields());
+
+  static constexpr const char* kInterfacesClassName = "[Ljava/lang/Class;";
+  static constexpr const char* kThrowsClassName     = "[[Ljava/lang/Class;";
+
+  // Class for "interfaces" field.
+  Handle<mirror::Class> interfaces_field_class =
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), kInterfacesClassName));
+  ASSERT_NOT_NULL(interfaces_field_class.Get());
+
+  // Class for "throws" field.
+  Handle<mirror::Class> throws_field_class =
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), kThrowsClassName));
+  ASSERT_NOT_NULL(throws_field_class.Get());
+
+  // Helper to test the static fields for correctness.
+  auto test_static_field = [&](size_t index,
+                               const char* field_name,
+                               Handle<mirror::Class>& handle_class,
+                               const char* class_name)
+      SHARED_REQUIRES(Locks::mutator_lock_) {
+    ArtField* field = &static_fields->At(index);
+    EXPECT_STREQ(field_name, field->GetName());
+    EXPECT_STREQ(class_name, field->GetTypeDescriptor());
+    EXPECT_EQ(handle_class.Get(), field->GetType</*kResolve*/true>())
+        << "Expected: " << PrettyClass(interfaces_field_class.Get()) << ", "
+        << "Actual: " << PrettyClass(field->GetType</*kResolve*/true>()) << ", "
+        << "field_name: " << field_name;
+    std::string temp;
+    EXPECT_STREQ("L$Proxy1234;", field->GetDeclaringClass()->GetDescriptor(&temp));
+    EXPECT_FALSE(field->IsPrimitiveType());
+  };
+
+  // Test "Class[] interfaces" field.
+  test_static_field(mirror::LambdaProxy::kStaticFieldIndexInterfaces,
+                    "interfaces",
+                    interfaces_field_class,
+                    kInterfacesClassName);
+
+  // Test "Class[][] throws" field.
+  test_static_field(mirror::LambdaProxy::kStaticFieldIndexThrows,
+                    "throws",
+                    throws_field_class,
+                    kThrowsClassName);
+}
+
+// Creates two proxy classes and check the art/mirror fields of their static fields.
+TEST_F(LambdaProxyTest, CheckArtMirrorFieldsOfProxyStaticFields) {
+  // gLogVerbosity.class_linker = true;  // Uncomment to enable class linker logging.
+
+  ASSERT_NOT_NULL(Thread::Current());
+
+  ScopedObjectAccess soa(Thread::Current());
+  soa_ = &soa;
+
+  // Must happen after CommonRuntimeTest finishes constructing the runtime.
+  jclass_loader_ = LoadDex(TEST_INTERFACE_ENCLOSING_CLASS_NAME);
+  jobject jclass_loader = jclass_loader_;
+
+  StackHandleScope<8> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
+
+  Handle<mirror::Class> proxyClass0;
+  Handle<mirror::Class> proxyClass1;
+  {
+    Handle<mirror::Class> L(hs.NewHandle(
+        class_linker_->FindClass(soa.Self(), MAKE_TEST_INTERFACE_NAME("L"), class_loader)));
+    ASSERT_TRUE(L.Get() != nullptr);
+
+    std::vector<mirror::Class*> interfaces = { L.Get() };
+    proxyClass0 = hs.NewHandle(GenerateProxyClass(soa, jclass_loader, "$Proxy0", interfaces));
+    proxyClass1 = hs.NewHandle(GenerateProxyClass(soa, jclass_loader, "$Proxy1", interfaces));
+  }
+
+  ASSERT_TRUE(proxyClass0.Get() != nullptr);
+  ASSERT_TRUE(proxyClass0->IsLambdaProxyClass());
+  ASSERT_TRUE(proxyClass0->IsInitialized());
+  ASSERT_TRUE(proxyClass1.Get() != nullptr);
+  ASSERT_TRUE(proxyClass1->IsLambdaProxyClass());
+  ASSERT_TRUE(proxyClass1->IsInitialized());
+
+  LengthPrefixedArray<ArtField>* static_fields0 = proxyClass0->GetSFieldsPtr();
+  ASSERT_TRUE(static_fields0 != nullptr);
+  ASSERT_EQ(2u, static_fields0->size());
+  LengthPrefixedArray<ArtField>* static_fields1 = proxyClass1->GetSFieldsPtr();
+  ASSERT_TRUE(static_fields1 != nullptr);
+  ASSERT_EQ(2u, static_fields1->size());
+
+  EXPECT_EQ(static_fields0->At(0).GetDeclaringClass(), proxyClass0.Get());
+  EXPECT_EQ(static_fields0->At(1).GetDeclaringClass(), proxyClass0.Get());
+  EXPECT_EQ(static_fields1->At(0).GetDeclaringClass(), proxyClass1.Get());
+  EXPECT_EQ(static_fields1->At(1).GetDeclaringClass(), proxyClass1.Get());
+
+  Handle<mirror::Field> field00 =
+      hs.NewHandle(mirror::Field::CreateFromArtField(soa.Self(), &static_fields0->At(0), true));
+  Handle<mirror::Field> field01 =
+      hs.NewHandle(mirror::Field::CreateFromArtField(soa.Self(), &static_fields0->At(1), true));
+  Handle<mirror::Field> field10 =
+      hs.NewHandle(mirror::Field::CreateFromArtField(soa.Self(), &static_fields1->At(0), true));
+  Handle<mirror::Field> field11 =
+      hs.NewHandle(mirror::Field::CreateFromArtField(soa.Self(), &static_fields1->At(1), true));
+  EXPECT_EQ(field00->GetArtField(), &static_fields0->At(0));
+  EXPECT_EQ(field01->GetArtField(), &static_fields0->At(1));
+  EXPECT_EQ(field10->GetArtField(), &static_fields1->At(0));
+  EXPECT_EQ(field11->GetArtField(), &static_fields1->At(1));
+}
+
+// TODO: make sure there's a non-abstract implementation of the single-abstract-method on the class.
+
+}  // namespace art