lldb/source/Commands/CommandObjectTrace.cpp - rust-lang/llvm-project - Git at Google

 //===-- CommandObjectTrace.cpp --------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #include "CommandObjectTrace.h"

 #include "llvm/Support/JSON.h"
 #include "llvm/Support/MemoryBuffer.h"

 #include "lldb/Core/Debugger.h"
 #include "lldb/Core/PluginManager.h"
 #include "lldb/Host/OptionParser.h"
 #include "lldb/Interpreter/CommandInterpreter.h"
 #include "lldb/Interpreter/CommandObject.h"
 #include "lldb/Interpreter/CommandOptionArgumentTable.h"
 #include "lldb/Interpreter/CommandReturnObject.h"
 #include "lldb/Interpreter/OptionArgParser.h"
 #include "lldb/Interpreter/OptionGroupFormat.h"
 #include "lldb/Interpreter/OptionValueBoolean.h"
 #include "lldb/Interpreter/OptionValueLanguage.h"
 #include "lldb/Interpreter/OptionValueString.h"
 #include "lldb/Interpreter/Options.h"
 #include "lldb/Target/Process.h"
 #include "lldb/Target/Trace.h"

 using namespace lldb;
 using namespace lldb_private;
 using namespace llvm;

 // CommandObjectTraceSave
 #define LLDB_OPTIONS_trace_save
 #include "CommandOptions.inc"

 #pragma mark CommandObjectTraceSave

 class CommandObjectTraceSave : public CommandObjectParsed {
 public:
   class CommandOptions : public Options {
   public:
     CommandOptions() { OptionParsingStarting(nullptr); }

     Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
                           ExecutionContext *execution_context) override {
       Status error;
       const int short_option = m_getopt_table[option_idx].val;

       switch (short_option) {
       case 'c': {
         m_compact = true;
         break;
       }
       default:
         llvm_unreachable("Unimplemented option");
       }
       return error;
     }

     void OptionParsingStarting(ExecutionContext *execution_context) override {
       m_compact = false;
     };

     llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
       return llvm::ArrayRef(g_trace_save_options);
     };

     bool m_compact;
   };

   Options *GetOptions() override { return &m_options; }

   CommandObjectTraceSave(CommandInterpreter &interpreter)
       : CommandObjectParsed(
             interpreter, "trace save",
             "Save the trace of the current target in the specified directory, "
             "which will be created if needed. "
             "This directory will contain a trace bundle, with all the "
             "necessary files the reconstruct the trace session even on a "
             "different computer. "
             "Part of this bundle is the bundle description file with the name "
             "trace.json. This file can be used by the \"trace load\" command "
             "to load this trace in LLDB."
             "Note: if the current target contains information of multiple "
             "processes or targets, they all will be included in the bundle.",
             "trace save [<cmd-options>] <bundle_directory>",
             eCommandRequiresProcess | eCommandTryTargetAPILock |
                 eCommandProcessMustBeLaunched | eCommandProcessMustBePaused |
                 eCommandProcessMustBeTraced) {
     CommandArgumentData bundle_dir{eArgTypeDirectoryName, eArgRepeatPlain};
     m_arguments.push_back({bundle_dir});
   }

   void
   HandleArgumentCompletion(CompletionRequest &request,
                            OptionElementVector &opt_element_vector) override {
     lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(
         GetCommandInterpreter(), lldb::eDiskFileCompletion, request, nullptr);
   }

   ~CommandObjectTraceSave() override = default;

 protected:
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     if (command.size() != 1) {
       result.AppendError("a single path to a directory where the trace bundle "
                          "will be created is required");
       return false;
     }

     FileSpec bundle_dir(command[0].ref());
     FileSystem::Instance().Resolve(bundle_dir);

     ProcessSP process_sp = m_exe_ctx.GetProcessSP();

     TraceSP trace_sp = process_sp->GetTarget().GetTrace();

     if (llvm::Expected<FileSpec> desc_file =
             trace_sp->SaveToDisk(bundle_dir, m_options.m_compact)) {
       result.AppendMessageWithFormatv(
           "Trace bundle description file written to: {0}", *desc_file);
       result.SetStatus(eReturnStatusSuccessFinishResult);
     } else {
       result.AppendError(toString(desc_file.takeError()));
     }

     return result.Succeeded();
   }

   CommandOptions m_options;
 };

 // CommandObjectTraceLoad
 #define LLDB_OPTIONS_trace_load
 #include "CommandOptions.inc"

 #pragma mark CommandObjectTraceLoad

 class CommandObjectTraceLoad : public CommandObjectParsed {
 public:
   class CommandOptions : public Options {
   public:
     CommandOptions() { OptionParsingStarting(nullptr); }

     ~CommandOptions() override = default;

     Status SetOptionValue(uint32_t option_idx, StringRef option_arg,
                           ExecutionContext *execution_context) override {
       Status error;
       const int short_option = m_getopt_table[option_idx].val;

       switch (short_option) {
       case 'v': {
         m_verbose = true;
         break;
       }
       default:
         llvm_unreachable("Unimplemented option");
       }
       return error;
     }

     void OptionParsingStarting(ExecutionContext *execution_context) override {
       m_verbose = false;
     }

     ArrayRef<OptionDefinition> GetDefinitions() override {
       return ArrayRef(g_trace_load_options);
     }

     bool m_verbose; // Enable verbose logging for debugging purposes.
   };

   CommandObjectTraceLoad(CommandInterpreter &interpreter)
       : CommandObjectParsed(
             interpreter, "trace load",
             "Load a post-mortem processor trace session from a trace bundle.",
             "trace load <trace_description_file>") {
     CommandArgumentData session_file_arg{eArgTypeFilename, eArgRepeatPlain};
     m_arguments.push_back({session_file_arg});
   }

   void
   HandleArgumentCompletion(CompletionRequest &request,
                            OptionElementVector &opt_element_vector) override {
     lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(
         GetCommandInterpreter(), lldb::eDiskFileCompletion, request, nullptr);
   }

   ~CommandObjectTraceLoad() override = default;

   Options *GetOptions() override { return &m_options; }

 protected:
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     if (command.size() != 1) {
       result.AppendError("a single path to a JSON file containing a the "
                          "description of the trace bundle is required");
       return false;
     }

     const FileSpec trace_description_file(command[0].ref());

     llvm::Expected<lldb::TraceSP> trace_or_err =
         Trace::LoadPostMortemTraceFromFile(GetDebugger(),
                                            trace_description_file);

     if (!trace_or_err) {
       result.AppendErrorWithFormat(
           "%s\n", llvm::toString(trace_or_err.takeError()).c_str());
       return false;
     }

     if (m_options.m_verbose) {
       result.AppendMessageWithFormatv("loading trace with plugin {0}\n",
                                       trace_or_err.get()->GetPluginName());
     }

     result.SetStatus(eReturnStatusSuccessFinishResult);
     return true;
   }

   CommandOptions m_options;
 };

 // CommandObjectTraceDump
 #define LLDB_OPTIONS_trace_dump
 #include "CommandOptions.inc"

 #pragma mark CommandObjectTraceDump

 class CommandObjectTraceDump : public CommandObjectParsed {
 public:
   class CommandOptions : public Options {
   public:
     CommandOptions() { OptionParsingStarting(nullptr); }

     ~CommandOptions() override = default;

     Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
                           ExecutionContext *execution_context) override {
       Status error;
       const int short_option = m_getopt_table[option_idx].val;

       switch (short_option) {
       case 'v': {
         m_verbose = true;
         break;
       }
       default:
         llvm_unreachable("Unimplemented option");
       }
       return error;
     }

     void OptionParsingStarting(ExecutionContext *execution_context) override {
       m_verbose = false;
     }

     llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
       return llvm::ArrayRef(g_trace_dump_options);
     }

     bool m_verbose; // Enable verbose logging for debugging purposes.
   };

   CommandObjectTraceDump(CommandInterpreter &interpreter)
       : CommandObjectParsed(interpreter, "trace dump",
                             "Dump the loaded processor trace data.",
                             "trace dump") {}

   ~CommandObjectTraceDump() override = default;

   Options *GetOptions() override { return &m_options; }

 protected:
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     Status error;
     // TODO: fill in the dumping code here!
     if (error.Success()) {
       result.SetStatus(eReturnStatusSuccessFinishResult);
     } else {
       result.AppendErrorWithFormat("%s\n", error.AsCString());
     }
     return result.Succeeded();
   }

   CommandOptions m_options;
 };

 // CommandObjectTraceSchema
 #define LLDB_OPTIONS_trace_schema
 #include "CommandOptions.inc"

 #pragma mark CommandObjectTraceSchema

 class CommandObjectTraceSchema : public CommandObjectParsed {
 public:
   class CommandOptions : public Options {
   public:
     CommandOptions() { OptionParsingStarting(nullptr); }

     ~CommandOptions() override = default;

     Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
                           ExecutionContext *execution_context) override {
       Status error;
       const int short_option = m_getopt_table[option_idx].val;

       switch (short_option) {
       case 'v': {
         m_verbose = true;
         break;
       }
       default:
         llvm_unreachable("Unimplemented option");
       }
       return error;
     }

     void OptionParsingStarting(ExecutionContext *execution_context) override {
       m_verbose = false;
     }

     llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
       return llvm::ArrayRef(g_trace_schema_options);
     }

     bool m_verbose; // Enable verbose logging for debugging purposes.
   };

   CommandObjectTraceSchema(CommandInterpreter &interpreter)
       : CommandObjectParsed(interpreter, "trace schema",
                             "Show the schema of the given trace plugin.",
                             "trace schema <plug-in>. Use the plug-in name "
                             "\"all\" to see all schemas.\n") {
     CommandArgumentData plugin_arg{eArgTypeNone, eArgRepeatPlain};
     m_arguments.push_back({plugin_arg});
   }

   ~CommandObjectTraceSchema() override = default;

   Options *GetOptions() override { return &m_options; }

 protected:
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     Status error;
     if (command.empty()) {
       result.AppendError(
           "trace schema cannot be invoked without a plug-in as argument");
       return false;
     }

     StringRef plugin_name(command[0].c_str());
     if (plugin_name == "all") {
       size_t index = 0;
       while (true) {
         StringRef schema = PluginManager::GetTraceSchema(index++);
         if (schema.empty())
           break;

         result.AppendMessage(schema);
       }
     } else {
       if (Expected<StringRef> schemaOrErr =
               Trace::FindPluginSchema(plugin_name))
         result.AppendMessage(*schemaOrErr);
       else
         error = schemaOrErr.takeError();
     }

     if (error.Success()) {
       result.SetStatus(eReturnStatusSuccessFinishResult);
     } else {
       result.AppendErrorWithFormat("%s\n", error.AsCString());
     }
     return result.Succeeded();
   }

   CommandOptions m_options;
 };

 // CommandObjectTrace

 CommandObjectTrace::CommandObjectTrace(CommandInterpreter &interpreter)
     : CommandObjectMultiword(interpreter, "trace",
                              "Commands for loading and using processor "
                              "trace information.",
                              "trace [<sub-command-options>]") {
   LoadSubCommand("load",
                  CommandObjectSP(new CommandObjectTraceLoad(interpreter)));
   LoadSubCommand("dump",
                  CommandObjectSP(new CommandObjectTraceDump(interpreter)));
   LoadSubCommand("save",
                  CommandObjectSP(new CommandObjectTraceSave(interpreter)));
   LoadSubCommand("schema",
                  CommandObjectSP(new CommandObjectTraceSchema(interpreter)));
 }

 CommandObjectTrace::~CommandObjectTrace() = default;

 Expected<CommandObjectSP> CommandObjectTraceProxy::DoGetProxyCommandObject() {
   ProcessSP process_sp = m_interpreter.GetExecutionContext().GetProcessSP();

   if (!process_sp)
     return createStringError(inconvertibleErrorCode(),
                              "Process not available.");
   if (m_live_debug_session_only && !process_sp->IsLiveDebugSession())
     return createStringError(inconvertibleErrorCode(),
                              "Process must be alive.");

   if (Expected<TraceSP> trace_sp = process_sp->GetTarget().GetTraceOrCreate())
     return GetDelegateCommand(**trace_sp);
   else
     return createStringError(inconvertibleErrorCode(),
                              "Tracing is not supported. %s",
                              toString(trace_sp.takeError()).c_str());
 }

 CommandObject *CommandObjectTraceProxy::GetProxyCommandObject() {
   if (Expected<CommandObjectSP> delegate = DoGetProxyCommandObject()) {
     m_delegate_sp = *delegate;
     m_delegate_error.clear();
     return m_delegate_sp.get();
   } else {
     m_delegate_sp.reset();
     m_delegate_error = toString(delegate.takeError());
     return nullptr;
   }
 }
	//===-- CommandObjectTrace.cpp --------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#include "CommandObjectTrace.h"

	#include "llvm/Support/JSON.h"
	#include "llvm/Support/MemoryBuffer.h"

	#include "lldb/Core/Debugger.h"
	#include "lldb/Core/PluginManager.h"
	#include "lldb/Host/OptionParser.h"
	#include "lldb/Interpreter/CommandInterpreter.h"
	#include "lldb/Interpreter/CommandObject.h"
	#include "lldb/Interpreter/CommandOptionArgumentTable.h"
	#include "lldb/Interpreter/CommandReturnObject.h"
	#include "lldb/Interpreter/OptionArgParser.h"
	#include "lldb/Interpreter/OptionGroupFormat.h"
	#include "lldb/Interpreter/OptionValueBoolean.h"
	#include "lldb/Interpreter/OptionValueLanguage.h"
	#include "lldb/Interpreter/OptionValueString.h"
	#include "lldb/Interpreter/Options.h"
	#include "lldb/Target/Process.h"
	#include "lldb/Target/Trace.h"

	using namespace lldb;
	using namespace lldb_private;
	using namespace llvm;

	// CommandObjectTraceSave
	#define LLDB_OPTIONS_trace_save
	#include "CommandOptions.inc"

	#pragma mark CommandObjectTraceSave

	class CommandObjectTraceSave : public CommandObjectParsed {
	public:
	class CommandOptions : public Options {
	public:
	CommandOptions() { OptionParsingStarting(nullptr); }

	Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
	ExecutionContext *execution_context) override {
	Status error;
	const int short_option = m_getopt_table[option_idx].val;

	switch (short_option) {
	case 'c': {
	m_compact = true;
	break;
	}
	default:
	llvm_unreachable("Unimplemented option");
	}
	return error;
	}

	void OptionParsingStarting(ExecutionContext *execution_context) override {
	m_compact = false;
	};

	llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
	return llvm::ArrayRef(g_trace_save_options);
	};

	bool m_compact;
	};

	Options *GetOptions() override { return &m_options; }

	CommandObjectTraceSave(CommandInterpreter &interpreter)
	: CommandObjectParsed(
	interpreter, "trace save",
	"Save the trace of the current target in the specified directory, "
	"which will be created if needed. "
	"This directory will contain a trace bundle, with all the "
	"necessary files the reconstruct the trace session even on a "
	"different computer. "
	"Part of this bundle is the bundle description file with the name "
	"trace.json. This file can be used by the \"trace load\" command "
	"to load this trace in LLDB."
	"Note: if the current target contains information of multiple "
	"processes or targets, they all will be included in the bundle.",
	"trace save [<cmd-options>] <bundle_directory>",
	eCommandRequiresProcess \| eCommandTryTargetAPILock \|
	eCommandProcessMustBeLaunched \| eCommandProcessMustBePaused \|
	eCommandProcessMustBeTraced) {
	CommandArgumentData bundle_dir{eArgTypeDirectoryName, eArgRepeatPlain};
	m_arguments.push_back({bundle_dir});
	}

	void
	HandleArgumentCompletion(CompletionRequest &request,
	OptionElementVector &opt_element_vector) override {
	lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(
	GetCommandInterpreter(), lldb::eDiskFileCompletion, request, nullptr);
	}

	~CommandObjectTraceSave() override = default;

	protected:
	bool DoExecute(Args &command, CommandReturnObject &result) override {
	if (command.size() != 1) {
	result.AppendError("a single path to a directory where the trace bundle "
	"will be created is required");
	return false;
	}

	FileSpec bundle_dir(command[0].ref());
	FileSystem::Instance().Resolve(bundle_dir);

	ProcessSP process_sp = m_exe_ctx.GetProcessSP();

	TraceSP trace_sp = process_sp->GetTarget().GetTrace();

	if (llvm::Expected<FileSpec> desc_file =
	trace_sp->SaveToDisk(bundle_dir, m_options.m_compact)) {
	result.AppendMessageWithFormatv(
	"Trace bundle description file written to: {0}", *desc_file);
	result.SetStatus(eReturnStatusSuccessFinishResult);
	} else {
	result.AppendError(toString(desc_file.takeError()));
	}

	return result.Succeeded();
	}

	CommandOptions m_options;
	};

	// CommandObjectTraceLoad
	#define LLDB_OPTIONS_trace_load
	#include "CommandOptions.inc"

	#pragma mark CommandObjectTraceLoad

	class CommandObjectTraceLoad : public CommandObjectParsed {
	public:
	class CommandOptions : public Options {
	public:
	CommandOptions() { OptionParsingStarting(nullptr); }

	~CommandOptions() override = default;

	Status SetOptionValue(uint32_t option_idx, StringRef option_arg,
	ExecutionContext *execution_context) override {
	Status error;
	const int short_option = m_getopt_table[option_idx].val;

	switch (short_option) {
	case 'v': {
	m_verbose = true;
	break;
	}
	default:
	llvm_unreachable("Unimplemented option");
	}
	return error;
	}

	void OptionParsingStarting(ExecutionContext *execution_context) override {
	m_verbose = false;
	}

	ArrayRef<OptionDefinition> GetDefinitions() override {
	return ArrayRef(g_trace_load_options);
	}

	bool m_verbose; // Enable verbose logging for debugging purposes.
	};

	CommandObjectTraceLoad(CommandInterpreter &interpreter)
	: CommandObjectParsed(
	interpreter, "trace load",
	"Load a post-mortem processor trace session from a trace bundle.",
	"trace load <trace_description_file>") {
	CommandArgumentData session_file_arg{eArgTypeFilename, eArgRepeatPlain};
	m_arguments.push_back({session_file_arg});
	}

	void
	HandleArgumentCompletion(CompletionRequest &request,
	OptionElementVector &opt_element_vector) override {
	lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(
	GetCommandInterpreter(), lldb::eDiskFileCompletion, request, nullptr);
	}

	~CommandObjectTraceLoad() override = default;

	Options *GetOptions() override { return &m_options; }

	protected:
	bool DoExecute(Args &command, CommandReturnObject &result) override {
	if (command.size() != 1) {
	result.AppendError("a single path to a JSON file containing a the "
	"description of the trace bundle is required");
	return false;
	}

	const FileSpec trace_description_file(command[0].ref());

	llvm::Expected<lldb::TraceSP> trace_or_err =
	Trace::LoadPostMortemTraceFromFile(GetDebugger(),
	trace_description_file);

	if (!trace_or_err) {
	result.AppendErrorWithFormat(
	"%s\n", llvm::toString(trace_or_err.takeError()).c_str());
	return false;
	}

	if (m_options.m_verbose) {
	result.AppendMessageWithFormatv("loading trace with plugin {0}\n",
	trace_or_err.get()->GetPluginName());
	}

	result.SetStatus(eReturnStatusSuccessFinishResult);
	return true;
	}

	CommandOptions m_options;
	};

	// CommandObjectTraceDump
	#define LLDB_OPTIONS_trace_dump
	#include "CommandOptions.inc"

	#pragma mark CommandObjectTraceDump

	class CommandObjectTraceDump : public CommandObjectParsed {
	public:
	class CommandOptions : public Options {
	public:
	CommandOptions() { OptionParsingStarting(nullptr); }

	~CommandOptions() override = default;

	Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
	ExecutionContext *execution_context) override {
	Status error;
	const int short_option = m_getopt_table[option_idx].val;

	switch (short_option) {
	case 'v': {
	m_verbose = true;
	break;
	}
	default:
	llvm_unreachable("Unimplemented option");
	}
	return error;
	}

	void OptionParsingStarting(ExecutionContext *execution_context) override {
	m_verbose = false;
	}

	llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
	return llvm::ArrayRef(g_trace_dump_options);
	}

	bool m_verbose; // Enable verbose logging for debugging purposes.
	};

	CommandObjectTraceDump(CommandInterpreter &interpreter)
	: CommandObjectParsed(interpreter, "trace dump",
	"Dump the loaded processor trace data.",
	"trace dump") {}

	~CommandObjectTraceDump() override = default;

	Options *GetOptions() override { return &m_options; }

	protected:
	bool DoExecute(Args &command, CommandReturnObject &result) override {
	Status error;
	// TODO: fill in the dumping code here!
	if (error.Success()) {
	result.SetStatus(eReturnStatusSuccessFinishResult);
	} else {
	result.AppendErrorWithFormat("%s\n", error.AsCString());
	}
	return result.Succeeded();
	}

	CommandOptions m_options;
	};

	// CommandObjectTraceSchema
	#define LLDB_OPTIONS_trace_schema
	#include "CommandOptions.inc"

	#pragma mark CommandObjectTraceSchema

	class CommandObjectTraceSchema : public CommandObjectParsed {
	public:
	class CommandOptions : public Options {
	public:
	CommandOptions() { OptionParsingStarting(nullptr); }

	~CommandOptions() override = default;

	Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
	ExecutionContext *execution_context) override {
	Status error;
	const int short_option = m_getopt_table[option_idx].val;

	switch (short_option) {
	case 'v': {
	m_verbose = true;
	break;
	}
	default:
	llvm_unreachable("Unimplemented option");
	}
	return error;
	}

	void OptionParsingStarting(ExecutionContext *execution_context) override {
	m_verbose = false;
	}

	llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
	return llvm::ArrayRef(g_trace_schema_options);
	}

	bool m_verbose; // Enable verbose logging for debugging purposes.
	};

	CommandObjectTraceSchema(CommandInterpreter &interpreter)
	: CommandObjectParsed(interpreter, "trace schema",
	"Show the schema of the given trace plugin.",
	"trace schema <plug-in>. Use the plug-in name "
	"\"all\" to see all schemas.\n") {
	CommandArgumentData plugin_arg{eArgTypeNone, eArgRepeatPlain};
	m_arguments.push_back({plugin_arg});
	}

	~CommandObjectTraceSchema() override = default;

	Options *GetOptions() override { return &m_options; }

	protected:
	bool DoExecute(Args &command, CommandReturnObject &result) override {
	Status error;
	if (command.empty()) {
	result.AppendError(
	"trace schema cannot be invoked without a plug-in as argument");
	return false;
	}

	StringRef plugin_name(command[0].c_str());
	if (plugin_name == "all") {
	size_t index = 0;
	while (true) {
	StringRef schema = PluginManager::GetTraceSchema(index++);
	if (schema.empty())
	break;

	result.AppendMessage(schema);
	}
	} else {
	if (Expected<StringRef> schemaOrErr =
	Trace::FindPluginSchema(plugin_name))
	result.AppendMessage(*schemaOrErr);
	else
	error = schemaOrErr.takeError();
	}

	if (error.Success()) {
	result.SetStatus(eReturnStatusSuccessFinishResult);
	} else {
	result.AppendErrorWithFormat("%s\n", error.AsCString());
	}
	return result.Succeeded();
	}

	CommandOptions m_options;
	};

	// CommandObjectTrace

	CommandObjectTrace::CommandObjectTrace(CommandInterpreter &interpreter)
	: CommandObjectMultiword(interpreter, "trace",
	"Commands for loading and using processor "
	"trace information.",
	"trace [<sub-command-options>]") {
	LoadSubCommand("load",
	CommandObjectSP(new CommandObjectTraceLoad(interpreter)));
	LoadSubCommand("dump",
	CommandObjectSP(new CommandObjectTraceDump(interpreter)));
	LoadSubCommand("save",
	CommandObjectSP(new CommandObjectTraceSave(interpreter)));
	LoadSubCommand("schema",
	CommandObjectSP(new CommandObjectTraceSchema(interpreter)));
	}

	CommandObjectTrace::~CommandObjectTrace() = default;

	Expected<CommandObjectSP> CommandObjectTraceProxy::DoGetProxyCommandObject() {
	ProcessSP process_sp = m_interpreter.GetExecutionContext().GetProcessSP();

	if (!process_sp)
	return createStringError(inconvertibleErrorCode(),
	"Process not available.");
	if (m_live_debug_session_only && !process_sp->IsLiveDebugSession())
	return createStringError(inconvertibleErrorCode(),
	"Process must be alive.");

	if (Expected<TraceSP> trace_sp = process_sp->GetTarget().GetTraceOrCreate())
	return GetDelegateCommand(**trace_sp);
	else
	return createStringError(inconvertibleErrorCode(),
	"Tracing is not supported. %s",
	toString(trace_sp.takeError()).c_str());
	}

	CommandObject *CommandObjectTraceProxy::GetProxyCommandObject() {
	if (Expected<CommandObjectSP> delegate = DoGetProxyCommandObject()) {
	m_delegate_sp = *delegate;
	m_delegate_error.clear();
	return m_delegate_sp.get();
	} else {
	m_delegate_sp.reset();
	m_delegate_error = toString(delegate.takeError());
	return nullptr;
	}
	}