[Courgette] Refactor: Manage AssemblyProgram and EncodedProgram with scoped_ptr.

courgette/program_detector.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "courgette/program_detector.h"
+
+#include <utility>
+
+#include "courgette/assembly_program.h"
+#include "courgette/disassembler.h"
+#include "courgette/disassembler_elf_32_arm.h"
+#include "courgette/disassembler_elf_32_x86.h"
+#include "courgette/disassembler_win32_x64.h"
+#include "courgette/disassembler_win32_x86.h"
+
+namespace courgette {
+
+namespace {
+
+// Returns a new instance of Disassembler subclass if binary data given in
+// |buffer| and |length| matches a known binary format, otherwise null.
+scoped_ptr<Disassembler> DetectDisassembler(const void* buffer, size_t length) {
+  scoped_ptr<Disassembler> disassembler;
+
+  disassembler.reset(new DisassemblerWin32X86(buffer, length));
+  if (disassembler->ParseHeader())
+    return disassembler;
+
+  disassembler.reset(new DisassemblerWin32X64(buffer, length));
+  if (disassembler->ParseHeader())
+    return disassembler;
+
+  disassembler.reset(new DisassemblerElf32X86(buffer, length));
+  if (disassembler->ParseHeader())
+    return disassembler;
+
+  disassembler.reset(new DisassemblerElf32ARM(buffer, length));
+  if (disassembler->ParseHeader())
+    return disassembler;
+
+  return nullptr;
+}
+
+}  // namespace
+
+Status DetectExecutableType(const void* buffer,
+                            size_t length,
+                            ExecutableType* type,
+                            size_t* detected_length) {
+  scoped_ptr<Disassembler> disassembler(DetectDisassembler(buffer, length));
+
+   if (!disassembler) {  // We failed to detect anything.
+    *type = EXE_UNKNOWN;
+    *detected_length = 0;
+    return C_INPUT_NOT_RECOGNIZED;
+  }
+
+  *type = disassembler->kind();
+  *detected_length = disassembler->length();
+  return C_OK;
+}
+
+Status ParseDetectedExecutable(const void* buffer,
+                               size_t length,
+                               scoped_ptr<AssemblyProgram>* output) {
+  output->reset();
+
+  scoped_ptr<Disassembler> disassembler(DetectDisassembler(buffer, length));
+  if (!disassembler)
+    return C_INPUT_NOT_RECOGNIZED;
+
+  scoped_ptr<AssemblyProgram> program(
+      new AssemblyProgram(disassembler->kind()));
+
+  if (!disassembler->Disassemble(program.get()))
+    return C_DISASSEMBLY_FAILED;
+
+  if (!program->TrimLabels())
+    return C_TRIM_FAILED;
+
+  *output = std::move(program);
+  return C_OK;
+}
+
+}  // namespace courgette