lldb/Interpreter/CommandInterpreter.h

//===-- CommandInterpreter.h ------------------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//

#ifndef liblldb_CommandInterpreter_h_
#define liblldb_CommandInterpreter_h_

#include "lldb/Core/Debugger.h"
#include "lldb/Core/IOHandler.h"
#include "lldb/Interpreter/CommandAlias.h"
#include "lldb/Interpreter/CommandHistory.h"
#include "lldb/Interpreter/CommandObject.h"
#include "lldb/Interpreter/ScriptInterpreter.h"
#include "lldb/Utility/Args.h"
#include "lldb/Utility/Broadcaster.h"
#include "lldb/Utility/CompletionRequest.h"
#include "lldb/Utility/Event.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/StringList.h"
#include "lldb/lldb-forward.h"
#include "lldb/lldb-private.h"
#include <mutex>

namespace lldb_private {

class CommandInterpreterRunOptions {
public:
  /// Construct a CommandInterpreterRunOptions object. This class is used to
  /// control all the instances where we run multiple commands, e.g.
  /// HandleCommands, HandleCommandsFromFile, RunCommandInterpreter.
  ///
  /// The meanings of the options in this object are:
  ///
  /// \param[in] stop_on_continue
  ///    If \b true, execution will end on the first command that causes the
  ///    process in the execution context to continue. If \b false, we won't
  ///    check the execution status.
  /// \param[in] stop_on_error
  ///    If \b true, execution will end on the first command that causes an
  ///    error.
  /// \param[in] stop_on_crash
  ///    If \b true, when a command causes the target to run, and the end of the
  ///    run is a signal or exception, stop executing the commands.
  /// \param[in] echo_commands
  ///    If \b true, echo the command before executing it. If \b false, execute
  ///    silently.
  /// \param[in] echo_comments
  ///    If \b true, echo command even if it is a pure comment line. If
  ///    \b false, print no ouput in this case. This setting has an effect only
  ///    if echo_commands is \b true.
  /// \param[in] print_results
  ///    If \b true and the command succeeds, print the results of the command
  ///    after executing it. If \b false, execute silently.
  /// \param[in] print_errors
  ///    If \b true and the command fails, print the results of the command
  ///    after executing it. If \b false, execute silently.
  /// \param[in] add_to_history
  ///    If \b true add the commands to the command history. If \b false, don't
  ///    add them.
  CommandInterpreterRunOptions(LazyBool stop_on_continue,
                               LazyBool stop_on_error, LazyBool stop_on_crash,
                               LazyBool echo_commands, LazyBool echo_comments,
                               LazyBool print_results, LazyBool print_errors,
                               LazyBool add_to_history)
      : m_stop_on_continue(stop_on_continue), m_stop_on_error(stop_on_error),
        m_stop_on_crash(stop_on_crash), m_echo_commands(echo_commands),
        m_echo_comment_commands(echo_comments), m_print_results(print_results),
        m_print_errors(print_errors), m_add_to_history(add_to_history) {}

  CommandInterpreterRunOptions()
      : m_stop_on_continue(eLazyBoolCalculate),
        m_stop_on_error(eLazyBoolCalculate),
        m_stop_on_crash(eLazyBoolCalculate),
        m_echo_commands(eLazyBoolCalculate),
        m_echo_comment_commands(eLazyBoolCalculate),
        m_print_results(eLazyBoolCalculate), m_print_errors(eLazyBoolCalculate),
        m_add_to_history(eLazyBoolCalculate) {}

  void SetSilent(bool silent) {
    LazyBool value = silent ? eLazyBoolNo : eLazyBoolYes;

    m_print_results = value;
    m_print_errors = value;
    m_echo_commands = value;
    m_echo_comment_commands = value;
    m_add_to_history = value;
  }
  // These return the default behaviors if the behavior is not
  // eLazyBoolCalculate. But I've also left the ivars public since for
  // different ways of running the interpreter you might want to force
  // different defaults...  In that case, just grab the LazyBool ivars directly
  // and do what you want with eLazyBoolCalculate.
  bool GetStopOnContinue() const { return DefaultToNo(m_stop_on_continue); }

  void SetStopOnContinue(bool stop_on_continue) {
    m_stop_on_continue = stop_on_continue ? eLazyBoolYes : eLazyBoolNo;
  }

  bool GetStopOnError() const { return DefaultToNo(m_stop_on_error); }

  void SetStopOnError(bool stop_on_error) {
    m_stop_on_error = stop_on_error ? eLazyBoolYes : eLazyBoolNo;
  }

  bool GetStopOnCrash() const { return DefaultToNo(m_stop_on_crash); }

  void SetStopOnCrash(bool stop_on_crash) {
    m_stop_on_crash = stop_on_crash ? eLazyBoolYes : eLazyBoolNo;
  }

  bool GetEchoCommands() const { return DefaultToYes(m_echo_commands); }

  void SetEchoCommands(bool echo_commands) {
    m_echo_commands = echo_commands ? eLazyBoolYes : eLazyBoolNo;
  }

  bool GetEchoCommentCommands() const {
    return DefaultToYes(m_echo_comment_commands);
  }

  void SetEchoCommentCommands(bool echo_comments) {
    m_echo_comment_commands = echo_comments ? eLazyBoolYes : eLazyBoolNo;
  }

  bool GetPrintResults() const { return DefaultToYes(m_print_results); }

  void SetPrintResults(bool print_results) {
    m_print_results = print_results ? eLazyBoolYes : eLazyBoolNo;
  }

  bool GetPrintErrors() const { return DefaultToYes(m_print_errors); }

  void SetPrintErrors(bool print_errors) {
    m_print_errors = print_errors ? eLazyBoolYes : eLazyBoolNo;
  }

  bool GetAddToHistory() const { return DefaultToYes(m_add_to_history); }

  void SetAddToHistory(bool add_to_history) {
    m_add_to_history = add_to_history ? eLazyBoolYes : eLazyBoolNo;
  }

  LazyBool m_stop_on_continue;
  LazyBool m_stop_on_error;
  LazyBool m_stop_on_crash;
  LazyBool m_echo_commands;
  LazyBool m_echo_comment_commands;
  LazyBool m_print_results;
  LazyBool m_print_errors;
  LazyBool m_add_to_history;

private:
  static bool DefaultToYes(LazyBool flag) {
    switch (flag) {
    case eLazyBoolNo:
      return false;
    default:
      return true;
    }
  }

  static bool DefaultToNo(LazyBool flag) {
    switch (flag) {
    case eLazyBoolYes:
      return true;
    default:
      return false;
    }
  }
};

class CommandInterpreter : public Broadcaster,
                           public Properties,
                           public IOHandlerDelegate {
public:
  enum {
    eBroadcastBitThreadShouldExit = (1 << 0),
    eBroadcastBitResetPrompt = (1 << 1),
    eBroadcastBitQuitCommandReceived = (1 << 2), // User entered quit
    eBroadcastBitAsynchronousOutputData = (1 << 3),
    eBroadcastBitAsynchronousErrorData = (1 << 4)
  };

  enum ChildrenTruncatedWarningStatus // tristate boolean to manage children
                                      // truncation warning
  { eNoTruncation = 0,                // never truncated
    eUnwarnedTruncation = 1,          // truncated but did not notify
    eWarnedTruncation = 2             // truncated and notified
  };

  enum CommandTypes {
    eCommandTypesBuiltin = 0x0001, // native commands such as "frame"
    eCommandTypesUserDef = 0x0002, // scripted commands
    eCommandTypesAliases = 0x0004, // aliases such as "po"
    eCommandTypesHidden = 0x0008,  // commands prefixed with an underscore
    eCommandTypesAllThem = 0xFFFF  // all commands
  };

  CommandInterpreter(Debugger &debugger, bool synchronous_execution);

  ~CommandInterpreter() override;

  // These two functions fill out the Broadcaster interface:

  static ConstString &GetStaticBroadcasterClass();

  ConstString &GetBroadcasterClass() const override {
    return GetStaticBroadcasterClass();
  }

  void SourceInitFileCwd(CommandReturnObject &result);
  void SourceInitFileHome(CommandReturnObject &result);

  bool AddCommand(llvm::StringRef name, const lldb::CommandObjectSP &cmd_sp,
                  bool can_replace);

  bool AddUserCommand(llvm::StringRef name, const lldb::CommandObjectSP &cmd_sp,
                      bool can_replace);

  lldb::CommandObjectSP GetCommandSPExact(llvm::StringRef cmd,
                                          bool include_aliases) const;

  CommandObject *GetCommandObject(llvm::StringRef cmd,
                                  StringList *matches = nullptr,
                                  StringList *descriptions = nullptr) const;

  bool CommandExists(llvm::StringRef cmd) const;

  bool AliasExists(llvm::StringRef cmd) const;

  bool UserCommandExists(llvm::StringRef cmd) const;

  CommandAlias *AddAlias(llvm::StringRef alias_name,
                         lldb::CommandObjectSP &command_obj_sp,
                         llvm::StringRef args_string = llvm::StringRef());

  // Remove a command if it is removable (python or regex command)
  bool RemoveCommand(llvm::StringRef cmd);

  bool RemoveAlias(llvm::StringRef alias_name);

  bool GetAliasFullName(llvm::StringRef cmd, std::string &full_name) const;

  bool RemoveUser(llvm::StringRef alias_name);

  void RemoveAllUser() { m_user_dict.clear(); }

  const CommandAlias *GetAlias(llvm::StringRef alias_name) const;

  CommandObject *BuildAliasResult(llvm::StringRef alias_name,
                                  std::string &raw_input_string,
                                  std::string &alias_result,
                                  CommandReturnObject &result);

  bool HandleCommand(const char *command_line, LazyBool add_to_history,
                     CommandReturnObject &result,
                     ExecutionContext *override_context = nullptr,
                     bool repeat_on_empty_command = true,
                     bool no_context_switching = false);

  bool WasInterrupted() const;

  /// Execute a list of commands in sequence.
  ///
  /// \param[in] commands
  ///    The list of commands to execute.
  /// \param[in,out] context
  ///    The execution context in which to run the commands. Can be nullptr in
  ///    which case the default
  ///    context will be used.
  /// \param[in] options
  ///    This object holds the options used to control when to stop, whether to
  ///    execute commands,
  ///    etc.
  /// \param[out] result
  ///    This is marked as succeeding with no output if all commands execute
  ///    safely,
  ///    and failed with some explanation if we aborted executing the commands
  ///    at some point.
  void HandleCommands(const StringList &commands, ExecutionContext *context,
                      CommandInterpreterRunOptions &options,
                      CommandReturnObject &result);

  /// Execute a list of commands from a file.
  ///
  /// \param[in] file
  ///    The file from which to read in commands.
  /// \param[in,out] context
  ///    The execution context in which to run the commands. Can be nullptr in
  ///    which case the default
  ///    context will be used.
  /// \param[in] options
  ///    This object holds the options used to control when to stop, whether to
  ///    execute commands,
  ///    etc.
  /// \param[out] result
  ///    This is marked as succeeding with no output if all commands execute
  ///    safely,
  ///    and failed with some explanation if we aborted executing the commands
  ///    at some point.
  void HandleCommandsFromFile(FileSpec &file, ExecutionContext *context,
                              CommandInterpreterRunOptions &options,
                              CommandReturnObject &result);

  CommandObject *GetCommandObjectForCommand(llvm::StringRef &command_line);

  // This handles command line completion.
  void HandleCompletion(CompletionRequest &request);

  // This version just returns matches, and doesn't compute the substring. It
  // is here so the Help command can call it for the first argument.
  void HandleCompletionMatches(CompletionRequest &request);

  int GetCommandNamesMatchingPartialString(const char *cmd_cstr,
                                           bool include_aliases,
                                           StringList &matches,
                                           StringList &descriptions);

  void GetHelp(CommandReturnObject &result,
               uint32_t types = eCommandTypesAllThem);

  void GetAliasHelp(const char *alias_name, StreamString &help_string);

  void OutputFormattedHelpText(Stream &strm, llvm::StringRef prefix,
                               llvm::StringRef help_text);

  void OutputFormattedHelpText(Stream &stream, llvm::StringRef command_word,
                               llvm::StringRef separator,
                               llvm::StringRef help_text, size_t max_word_len);

  // this mimics OutputFormattedHelpText but it does perform a much simpler
  // formatting, basically ensuring line alignment. This is only good if you
  // have some complicated layout for your help text and want as little help as
  // reasonable in properly displaying it. Most of the times, you simply want
  // to type some text and have it printed in a reasonable way on screen. If
  // so, use OutputFormattedHelpText
  void OutputHelpText(Stream &stream, llvm::StringRef command_word,
                      llvm::StringRef separator, llvm::StringRef help_text,
                      uint32_t max_word_len);

  Debugger &GetDebugger() { return m_debugger; }

  ExecutionContext GetExecutionContext() {
    const bool thread_and_frame_only_if_stopped = true;
    return m_exe_ctx_ref.Lock(thread_and_frame_only_if_stopped);
  }

  void UpdateExecutionContext(ExecutionContext *override_context);

  lldb::PlatformSP GetPlatform(bool prefer_target_platform);

  const char *ProcessEmbeddedScriptCommands(const char *arg);

  void UpdatePrompt(llvm::StringRef prompt);

  bool Confirm(llvm::StringRef message, bool default_answer);

  void LoadCommandDictionary();

  void Initialize();

  void Clear();

  bool HasCommands() const;

  bool HasAliases() const;

  bool HasUserCommands() const;

  bool HasAliasOptions() const;

  void BuildAliasCommandArgs(CommandObject *alias_cmd_obj,
                             const char *alias_name, Args &cmd_args,
                             std::string &raw_input_string,
                             CommandReturnObject &result);

  int GetOptionArgumentPosition(const char *in_string);

  void SkipLLDBInitFiles(bool skip_lldbinit_files) {
    m_skip_lldbinit_files = skip_lldbinit_files;
  }

  void SkipAppInitFiles(bool skip_app_init_files) {
    m_skip_app_init_files = skip_app_init_files;
  }

  bool GetSynchronous();

  void FindCommandsForApropos(llvm::StringRef word, StringList &commands_found,
                              StringList &commands_help,
                              bool search_builtin_commands,
                              bool search_user_commands,
                              bool search_alias_commands);

  bool GetBatchCommandMode() { return m_batch_command_mode; }

  bool SetBatchCommandMode(bool value) {
    const bool old_value = m_batch_command_mode;
    m_batch_command_mode = value;
    return old_value;
  }

  void ChildrenTruncated() {
    if (m_truncation_warning == eNoTruncation)
      m_truncation_warning = eUnwarnedTruncation;
  }

  bool TruncationWarningNecessary() {
    return (m_truncation_warning == eUnwarnedTruncation);
  }

  void TruncationWarningGiven() { m_truncation_warning = eWarnedTruncation; }

  const char *TruncationWarningText() {
    return "*** Some of your variables have more members than the debugger "
           "will show by default. To show all of them, you can either use the "
           "--show-all-children option to %s or raise the limit by changing "
           "the target.max-children-count setting.\n";
  }

  CommandHistory &GetCommandHistory() { return m_command_history; }

  bool IsActive();

  void RunCommandInterpreter(bool auto_handle_events, bool spawn_thread,
                             CommandInterpreterRunOptions &options);

  void GetLLDBCommandsFromIOHandler(const char *prompt,
                                    IOHandlerDelegate &delegate,
                                    void *baton = nullptr);

  void GetPythonCommandsFromIOHandler(const char *prompt,
                                      IOHandlerDelegate &delegate,
                                      void *baton = nullptr);

  const char *GetCommandPrefix();

  // Properties
  bool GetExpandRegexAliases() const;

  bool GetPromptOnQuit() const;

  void SetPromptOnQuit(bool enable);

  bool GetEchoCommands() const;
  void SetEchoCommands(bool enable);

  bool GetEchoCommentCommands() const;
  void SetEchoCommentCommands(bool enable);

  /// Specify if the command interpreter should allow that the user can
  /// specify a custom exit code when calling 'quit'.
  void AllowExitCodeOnQuit(bool allow);

  /// Sets the exit code for the quit command.
  /// \param[in] exit_code
  ///     The exit code that the driver should return on exit.
  /// \return True if the exit code was successfully set; false if the
  ///         interpreter doesn't allow custom exit codes.
  /// \see AllowExitCodeOnQuit
  LLVM_NODISCARD bool SetQuitExitCode(int exit_code);

  /// Returns the exit code that the user has specified when running the
  /// 'quit' command.
  /// \param[out] exited
  ///     Set to true if the user has called quit with a custom exit code.
  int GetQuitExitCode(bool &exited) const;

  void ResolveCommand(const char *command_line, CommandReturnObject &result);

  bool GetStopCmdSourceOnError() const;

  uint32_t GetNumErrors() const { return m_num_errors; }

  bool GetQuitRequested() const { return m_quit_requested; }

  lldb::IOHandlerSP
  GetIOHandler(bool force_create = false,
               CommandInterpreterRunOptions *options = nullptr);

  bool GetStoppedForCrash() const { return m_stopped_for_crash; }

  bool GetSpaceReplPrompts() const;

protected:
  friend class Debugger;

  // IOHandlerDelegate functions
  void IOHandlerInputComplete(IOHandler &io_handler,
                              std::string &line) override;

  ConstString IOHandlerGetControlSequence(char ch) override {
    if (ch == 'd')
      return ConstString("quit\n");
    return ConstString();
  }

  bool IOHandlerInterrupt(IOHandler &io_handler) override;

  void GetProcessOutput();

  bool DidProcessStopAbnormally() const;

  void SetSynchronous(bool value);

  lldb::CommandObjectSP GetCommandSP(llvm::StringRef cmd,
                                     bool include_aliases = true,
                                     bool exact = true,
                                     StringList *matches = nullptr,
                                     StringList *descriptions = nullptr) const;

private:
  Status PreprocessCommand(std::string &command);

  void SourceInitFile(FileSpec file, CommandReturnObject &result);

  // Completely resolves aliases and abbreviations, returning a pointer to the
  // final command object and updating command_line to the fully substituted
  // and translated command.
  CommandObject *ResolveCommandImpl(std::string &command_line,
                                    CommandReturnObject &result);

  void FindCommandsForApropos(llvm::StringRef word, StringList &commands_found,
                              StringList &commands_help,
                              CommandObject::CommandMap &command_map);

  // An interruptible wrapper around the stream output
  void PrintCommandOutput(Stream &stream, llvm::StringRef str);

  bool EchoCommandNonInteractive(llvm::StringRef line,
                                 const Flags &io_handler_flags) const;

  // A very simple state machine which models the command handling transitions
  enum class CommandHandlingState {
    eIdle,
    eInProgress,
    eInterrupted,
  };

  std::atomic<CommandHandlingState> m_command_state{
      CommandHandlingState::eIdle};

  int m_iohandler_nesting_level = 0;

  void StartHandlingCommand();
  void FinishHandlingCommand();
  bool InterruptCommand();

  Debugger &m_debugger; // The debugger session that this interpreter is
                        // associated with
  ExecutionContextRef m_exe_ctx_ref; // The current execution context to use
                                     // when handling commands
  bool m_synchronous_execution;
  bool m_skip_lldbinit_files;
  bool m_skip_app_init_files;
  CommandObject::CommandMap m_command_dict; // Stores basic built-in commands
                                            // (they cannot be deleted, removed
                                            // or overwritten).
  CommandObject::CommandMap
      m_alias_dict; // Stores user aliases/abbreviations for commands
  CommandObject::CommandMap m_user_dict; // Stores user-defined commands
  CommandHistory m_command_history;
  std::string m_repeat_command; // Stores the command that will be executed for
                                // an empty command string.
  lldb::IOHandlerSP m_command_io_handler_sp;
  char m_comment_char;
  bool m_batch_command_mode;
  ChildrenTruncatedWarningStatus m_truncation_warning; // Whether we truncated
                                                       // children and whether
                                                       // the user has been told
  uint32_t m_command_source_depth;
  std::vector<uint32_t> m_command_source_flags;
  uint32_t m_num_errors;
  bool m_quit_requested;
  bool m_stopped_for_crash;

  // The exit code the user has requested when calling the 'quit' command.
  // No value means the user hasn't set a custom exit code so far.
  llvm::Optional<int> m_quit_exit_code;
  // If the driver is accepts custom exit codes for the 'quit' command.
  bool m_allow_exit_code = false;
};

} // namespace lldb_private

#endif // liblldb_CommandInterpreter_h_