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.h b/compiler/dex/dex_to_dex_decompiler.h
new file mode 100644
index 0000000..5502ca2
--- /dev/null
+++ b/compiler/dex/dex_to_dex_decompiler.h
@@ -0,0 +1,38 @@
+/*
+ * 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.
+ */
+
+#ifndef ART_COMPILER_DEX_DEX_TO_DEX_DECOMPILER_H_
+#define ART_COMPILER_DEX_DEX_TO_DEX_DECOMPILER_H_
+
+#include "base/array_ref.h"
+#include "dex_file.h"
+
+namespace art {
+namespace optimizer {
+
+// "Decompile", that is unquicken, the code item provided, given the
+// associated quickening data.
+// TODO: code_item isn't really a const element, but changing it
+// to non-const has too many repercussions on the code base. We make it
+// consistent with DexToDexCompiler, but we should really change it to
+// DexFile::CodeItem*.
+bool ArtDecompileDEX(const DexFile::CodeItem& code_item,
+                     const ArrayRef<const uint8_t>& quickened_data);
+
+}  // namespace optimizer
+}  // namespace art
+
+#endif  // ART_COMPILER_DEX_DEX_TO_DEX_DECOMPILER_H_