riscv64: Add basic disassembler.

Add a disassembler that differentiates between 16-bit and
32-bit instructions and disassembles 32-bit LUI, AUIPC,
branches, loads, stores and integral arithmetic operations.

Test: m dump-oat  # and manually inspect output
Bug: 283082089
Change-Id: I0946aaf2bb99d5539efbcecabc111def2a512439

1 files changed, 42 insertions, 0 deletions

diff --git a/disassembler/disassembler_riscv64.h b/disassembler/disassembler_riscv64.h
new file mode 100644
index 0000000000..739d58d33a
--- /dev/null
+++ b/disassembler/disassembler_riscv64.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2023 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_DISASSEMBLER_DISASSEMBLER_RISCV64_H_
+#define ART_DISASSEMBLER_DISASSEMBLER_RISCV64_H_
+
+#include "disassembler.h"
+
+namespace art {
+namespace riscv64 {
+
+class DisassemblerRiscv64 final : public Disassembler {
+ public:
+  explicit DisassemblerRiscv64(DisassemblerOptions* options)
+      : Disassembler(options) {}
+
+  size_t Dump(std::ostream& os, const uint8_t* begin) override;
+  void Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) override;
+
+ private:
+  class Printer;
+
+  DISALLOW_COPY_AND_ASSIGN(DisassemblerRiscv64);
+};
+
+}  // namespace riscv64
+}  // namespace art
+
+#endif  // ART_DISASSEMBLER_DISASSEMBLER_RISCV64_H_