Lshal: support commands.

Support the following commands:
  lshal list
  lshal list -itrpc
  lshal help
  lshal help list
  lshal list -h
  lshal list --help

Test: run these commands
Bug: 37725279
Change-Id: I970fbc8d250d43f57e92f783229e0645d7e8df4e
diff --git a/cmds/lshal/ListCommand.h b/cmds/lshal/ListCommand.h
new file mode 100644
index 0000000..42c965f
--- /dev/null
+++ b/cmds/lshal/ListCommand.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2017 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 FRAMEWORK_NATIVE_CMDS_LSHAL_LIST_COMMAND_H_
+#define FRAMEWORK_NATIVE_CMDS_LSHAL_LIST_COMMAND_H_
+
+#include <stdint.h>
+
+#include <fstream>
+#include <string>
+#include <vector>
+
+#include <android-base/macros.h>
+#include <android/hidl/manager/1.0/IServiceManager.h>
+
+#include "NullableOStream.h"
+#include "TableEntry.h"
+#include "utils.h"
+
+namespace android {
+namespace lshal {
+
+class Lshal;
+
+class ListCommand {
+public:
+    ListCommand(Lshal &lshal);
+    Status main(const std::string &command, const Arg &arg);
+private:
+    Status parseArgs(const std::string &command, const Arg &arg);
+    Status fetch();
+    void postprocess();
+    void dump();
+    void putEntry(TableEntrySource source, TableEntry &&entry);
+    Status fetchPassthrough(const sp<::android::hidl::manager::V1_0::IServiceManager> &manager);
+    Status fetchBinderized(const sp<::android::hidl::manager::V1_0::IServiceManager> &manager);
+    Status fetchAllLibraries(const sp<::android::hidl::manager::V1_0::IServiceManager> &manager);
+    bool getReferencedPids(
+        pid_t serverPid, std::map<uint64_t, Pids> *objects) const;
+    void dumpTable();
+    void dumpVintf() const;
+    void printLine(
+            const std::string &interfaceName,
+            const std::string &transport,
+            const std::string &arch,
+            const std::string &server,
+            const std::string &serverCmdline,
+            const std::string &address, const std::string &clients,
+            const std::string &clientCmdlines) const ;
+    // Return /proc/{pid}/cmdline if it exists, else empty string.
+    const std::string &getCmdline(pid_t pid);
+    // Call getCmdline on all pid in pids. If it returns empty string, the process might
+    // have died, and the pid is removed from pids.
+    void removeDeadProcesses(Pids *pids);
+    void forEachTable(const std::function<void(Table &)> &f);
+    void forEachTable(const std::function<void(const Table &)> &f) const;
+
+    Lshal &mLshal;
+
+    Table mServicesTable{};
+    Table mPassthroughRefTable{};
+    Table mImplementationsTable{};
+
+    NullableOStream<std::ostream> mErr;
+    NullableOStream<std::ostream> mOut;
+    NullableOStream<std::ofstream> mFileOutput = nullptr;
+    TableEntryCompare mSortColumn = nullptr;
+    TableEntrySelect mSelectedColumns = 0;
+    // If true, cmdlines will be printed instead of pid.
+    bool mEnableCmdlines = false;
+
+    // If true, calls IBase::debug(...) on each service.
+    bool mEmitDebugInfo = false;
+
+    bool mVintf = false;
+    // If an entry does not exist, need to ask /proc/{pid}/cmdline to get it.
+    // If an entry exist but is an empty string, process might have died.
+    // If an entry exist and not empty, it contains the cached content of /proc/{pid}/cmdline.
+    std::map<pid_t, std::string> mCmdlines;
+
+    DISALLOW_COPY_AND_ASSIGN(ListCommand);
+};
+
+
+}  // namespace lshal
+}  // namespace android
+
+#endif  // FRAMEWORK_NATIVE_CMDS_LSHAL_LIST_COMMAND_H_