Add dequickening support.

Both vdex and BCI require full dequickening support. This
change implements dequickening by using the existing encoded
quickening, and adds the checkcast quickening to that encoding.

bug: 30937355
bug: 32369913
Test: dex_to_dex_decompiler_test.cc test-art-host

Change-Id: Ie95f46946d59b28157d6e47dcf4a859be032d1c3
diff --git a/compiler/dex/dex_to_dex_decompiler_test.cc b/compiler/dex/dex_to_dex_decompiler_test.cc
new file mode 100644
index 0000000..ea6c7a2
--- /dev/null
+++ b/compiler/dex/dex_to_dex_decompiler_test.cc
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2016 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 "dex/dex_to_dex_decompiler.h"
+
+#include "class_linker.h"
+#include "compiler/common_compiler_test.h"
+#include "compiler/compiled_method.h"
+#include "compiler/driver/compiler_options.h"
+#include "compiler/driver/compiler_driver.h"
+#include "compiler_callbacks.h"
+#include "dex_file.h"
+#include "handle_scope-inl.h"
+#include "verifier/method_verifier-inl.h"
+#include "mirror/class_loader.h"
+#include "runtime.h"
+#include "thread.h"
+#include "scoped_thread_state_change-inl.h"
+
+namespace art {
+
+class DexToDexDecompilerTest : public CommonCompilerTest {
+ public:
+  void CompileAll(jobject class_loader) REQUIRES(!Locks::mutator_lock_) {
+    TimingLogger timings("CompilerDriverTest::CompileAll", false, false);
+    TimingLogger::ScopedTiming t(__FUNCTION__, &timings);
+    compiler_options_->boot_image_ = false;
+    compiler_options_->SetCompilerFilter(CompilerFilter::kInterpretOnly);
+    compiler_driver_->CompileAll(class_loader,
+                                 GetDexFiles(class_loader),
+                                 /* verifier_deps */ nullptr,
+                                 &timings);
+  }
+
+  void RunTest(const char* dex_name) {
+    Thread* self = Thread::Current();
+    // First load the original dex file.
+    jobject original_class_loader;
+    {
+      ScopedObjectAccess soa(self);
+      original_class_loader = LoadDex(dex_name);
+    }
+    const DexFile* original_dex_file = GetDexFiles(original_class_loader)[0];
+
+    // Load the dex file again and make it writable to quicken them.
+    jobject class_loader;
+    const DexFile* updated_dex_file = nullptr;
+    {
+      ScopedObjectAccess soa(self);
+      class_loader = LoadDex(dex_name);
+      updated_dex_file = GetDexFiles(class_loader)[0];
+      Runtime::Current()->GetClassLinker()->RegisterDexFile(
+          *updated_dex_file, soa.Decode<mirror::ClassLoader>(class_loader).Ptr());
+    }
+    // The dex files should be identical.
+    int cmp = memcmp(original_dex_file->Begin(),
+                     updated_dex_file->Begin(),
+                     updated_dex_file->Size());
+    ASSERT_EQ(0, cmp);
+
+    updated_dex_file->EnableWrite();
+    CompileAll(class_loader);
+    // The dex files should be different after quickening.
+    cmp = memcmp(original_dex_file->Begin(), updated_dex_file->Begin(), updated_dex_file->Size());
+    ASSERT_NE(0, cmp);
+
+    // Unquicken the dex file.
+    for (uint32_t i = 0; i < updated_dex_file->NumClassDefs(); ++i) {
+      const DexFile::ClassDef& class_def = updated_dex_file->GetClassDef(i);
+      const uint8_t* class_data = updated_dex_file->GetClassData(class_def);
+      if (class_data == nullptr) {
+        continue;
+      }
+      ClassDataItemIterator it(*updated_dex_file, class_data);
+      // Skip fields
+      while (it.HasNextStaticField()) {
+        it.Next();
+      }
+      while (it.HasNextInstanceField()) {
+        it.Next();
+      }
+
+      // Unquicken each method.
+      while (it.HasNextDirectMethod()) {
+        uint32_t method_idx = it.GetMemberIndex();
+        CompiledMethod* compiled_method =
+            compiler_driver_->GetCompiledMethod(MethodReference(updated_dex_file, method_idx));
+        ArrayRef<const uint8_t> table;
+        if (compiled_method != nullptr) {
+          table = compiled_method->GetVmapTable();
+        }
+        optimizer::ArtDecompileDEX(*it.GetMethodCodeItem(), table);
+        it.Next();
+      }
+      while (it.HasNextVirtualMethod()) {
+        uint32_t method_idx = it.GetMemberIndex();
+        CompiledMethod* compiled_method =
+            compiler_driver_->GetCompiledMethod(MethodReference(updated_dex_file, method_idx));
+        ArrayRef<const uint8_t> table;
+        if (compiled_method != nullptr) {
+          table = compiled_method->GetVmapTable();
+        }
+        optimizer::ArtDecompileDEX(*it.GetMethodCodeItem(), table);
+        it.Next();
+      }
+      DCHECK(!it.HasNext());
+    }
+
+    // Make sure after unquickening we go back to the same contents as the original dex file.
+    cmp = memcmp(original_dex_file->Begin(), updated_dex_file->Begin(), updated_dex_file->Size());
+    ASSERT_EQ(0, cmp);
+  }
+};
+
+TEST_F(DexToDexDecompilerTest, VerifierDeps) {
+  RunTest("VerifierDeps");
+}
+
+TEST_F(DexToDexDecompilerTest, DexToDexDecompiler) {
+  RunTest("DexToDexDecompiler");
+}
+
+}  // namespace art